Printed wiring board

Technical Field

0001The present invention relates to a printed wiring board for mounting electronic parts such as capacitors, IC and the like on the outer layer, more particularly, a printed wiring board adaptable to narrow pitching of solder bump for mounting electronic parts.

Background Art

0002Recent years, high performance is remarkable in electronics represented by portable telephones and communication terminals. And, for these electronics is used a printed wiring board having IC chips mounted thereon. As a form of mounting an IC chip on a printed wiring board, a flip chip type of directly mounting an IC chip on the surface of a printed wiring board is widely employed. As such a printed wiring board, there has been known the one comprising a core substrate, a build-up layer formed on the core substrate and connecting pads for mounting an IC chip through a solder bump on the surface of the build-up layer.

0003Here, a printed wiring board is made of epoxy resin, BT (bismaleimide triazine) resin phenol resin and the like formed with reinforcement such as glass fiber or the like. The thermal expansion coefficient of these core substrates is about 12-20 ppm/°C (30 - 200°C) and about 4 times larger than that (about 3.5 ppm/°C) of silicon of the IC chip.

0004Therefore, the flip-chip type has, in case of repeating temperature change with heat generation, the possibility of destroying the solder bump due to differences in thermal expansion and heat contraction between the IC chip and the core substrate. For solving such problem, there is proposed a method of interposing an interposer having a thermal expansion coefficient between the printed wiring board and the IC (refer to <patcit id="pcit0001" dnum="JP59000996A"><text>Japanese unexamined patent application No. 59-996</text></patcit>).

0005However, the method of interposing an interposer between the IC and the printed wiring board cannot meet needs of downsizing of electronic parts. Further, addition of an excessive part such as the interposer makes the cost high.

0006Accordingly, an object of the present invention is to solve the above problem of prior art by providing a printed wiring board having excellent connection reliability and insulation reliability which can make downsizing and low cost possible even with narrow pitch structure having conductor pads (connecting pads) provided for mounting solder bumps thereon with a pitch of 200 µm or less.

Disclosure of the Invention

0007The inventors have, as a result of earnest study for realizing the above object, completed the invention having the following essentials and construction based on such knowledge that connection reliability and insulation reliability between the solder bump and electronic parts such as IC chips and the like are improved by limiting the ratio of height of the solder bump provided on the connecting pad exposed from an opening provided in a solder resist layer to diameter of the opening to a predetermined range so as to contribute to the downsizing and low cost.

0008That is, the present invention provides <ol id="ol0001" compact="compact"><li>(1) a printed wiring board comprising a wiring substrate provided with at least one conductor circuit, a solder resist layer formed on the surface of the wiring substrate, covering the at least one conductor circuit, conductor pads formed on a part of the at least one conductor circuit exposed from respective openings provided in the solder resist layer for mounting electronic parts, and solder bumps formed on the respective conductor pads, wherein the conductor pads are arranged with a pitch of 200 µm or less and the ratio (H/D) of a height H of the solder bump from the surface of the solder resist layer to an opening diameter D of the opening is 0.55 to 1.0. Further, the present invention provides</li><li>(2) a printed wiring board comprising a wiring substrate provided with at least one conductor circuit, a solder resist layer formed on the surface of the wiring substrate, covering the at least one conductor circuit, conductor pads formed on a part of the at least one conductor circuit exposed from the respective openings provided in the solder resist for mounting electronic parts, solder bumps formed on the respective conductor pads, and an under fill material or resin for sealing a gap or space defined between electronic parts mounted through the solder bumps and the solder resist layer, wherein the conductor pads are arranged with a pitch of 200 µm or less and the ratio (H/D) of a height H of the solder bump from the surface of the solder resist layer to an opening diameter D of the opening is 0.55 to 1.0.</li></ol>

0009In the present invention, the surface of the solder resist layer can be flattened at least in an electronic part mounting region, and it is desirable that maximum surface roughness (uneven amount) of the flattened surface (1st uneven face) is made 0.8 to 3.0 µ m.

0010Further, in the present invention, the surface of the flattened solder resist layer can be further roughened, and it is desirable that surface roughness of the surface (2nd uneven face) of the roughened solder resist layer is smaller than the maximum surface roughness of the flattened surface and 0.2 to 0.5 µm at an arithmetic mean roughness (Ra).

0011Further, in the present invention, it is desirable that the conductor pad defined as a part of the conductor circuit exposed from the opening provided in the solder resist layer is formed in the form of a filled via which is defined by a plated conductor completely filled within an opening provided in an interlaminar insulative resin layer positioned at the outermost layer, and an uneven amount of the filled via surface exposed from the interlaminar insulative resin layer surface is -5 µm to +5 µm in relation to the thickness of the conductor circuit formed on the interlaminar insulative resin layer.

0012Further, in the present invention, "conductor pad" is defined as a part of the conductor circuit exposed from the opening provided in the solder resist layer. The conductor circuit can be, for instance, formed in the form (connecting pad) of utilizing a part of the conductor circuit, the form of a viahole (including the filled via in which plated conductor is completely filled within the opening provided in the resin insulating layer) or the form consisting of the viahole and the conductor circuit, so that in a broad sense, it indicates a part of the conductor circuit including the connecting pads and the viaholes.

0013Further, in the present invention, "opening diameter (D)" of the opening provided in the solder resist layer means a "diameter" of the opening when the opening side wall is not tapered, and means a diameter (of the opening upper part) of the opening exposed on the solder resist layer surface when the opening side wall is tapered.

0014Further, in the present invention, "maximum surface roughness" means, as schematically shown in <figref idref="f0008">Fig. 8</figref>, in the electronic part mounting region, the maximum value in differences X1, X2, X3, X4, X5, ... between the height of the solder resist layer on the conductor pad or the conductor circuit and that of the solder resist layer on an adjacent conductor pad non-forming portion or a conductor circuit non-forming portion.

0015Further, "arithmetic mean roughness" means arithmetic mean roughness (Ra) prescribed in JIS B0601.

0016According to the present invention, a height of the solder bump can be made comparatively large by making a ratio (H/D) of the height H of the solder bump from the solder resist layer surface to the opening diameter D of the opening 0.55 or more, thereby easily deforming the solder bump itself and enlarging volume (amount) of the solder. As a result, stress which can be absorbed by the solder is increased to improve connection reliability. On the other hand, the solder fused between the adjacent solder bumps is hard to move by making a ratio (H/D) of the height H of the solder bump from the solder resist layer surface to the opening diameter D of the opening 1.0 or less, thereby hardly moving the solder molten between adjacent solder bumps to control irregular solder bump height and to prevent short-circuit of adjacent solder bumps. As a result, connection reliability and insulation reliability are improved.

0017Further, the flattened surface (1st uneven face) in at least the electronic part mounting region of the solder resist layer surface can decrease generation of void in the under fill material filled between the solder resist layer surface and the mounted electronic parts by making the maximum surface roughness (uneven amount) 0.8 to 3.0 <i>µ</i>m. As a result, connection reliability is improved.

0018Further, when surface roughness of the surface (2nd uneven face) of the roughened solder resist layer is made smaller than an uneven amount of the flattened surface and about 0.2 to 0.5µ m at an arithmetic mean roughness Ra, adhesion between the solder resist layer surface and the under fill material can be improved, and residual material such as flux, cleaning solution and the like on the solder resist layer surface can be lessened. As a result, connection reliability and insulation reliability are improved.

0019Further, the conductor pad is formed into a filled via and the uneven amount of the filled via surface exposed from the outermost interlaminar insulative resin layer surface is made from -5 µm to +5 µm in relation to the thickness of a conductor circuit formed on the interlaminar insulative resin layer, thereby increasing contact points between the filled via and the solder ball so as to improve wettability in case of forming a solder bump, to lessen catching up or involvement of void within the solder bump and missing bump and to obtain fine adaptability.

0020Further, without requiring any interposer, the board can be thinned and the cost can be lowered at the same time.

Brief Description of the Drawings

0021<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a sectional view of the printed wiring board according to the present invention.</li><li><figref idref="f0002">Fig. 2</figref> is a sectional view showing a state of mounting an IC chip on the printed wiring board shown in <figref idref="f0001">Fig. 1</figref> and placing on a daughter board.</li><li><figref idref="f0003">Figs. 3A to 3C</figref> are views explaining steps of forming solder bumps on the printed wiring board.</li><li><figref idref="f0004">Figs 4A to 4B</figref> are schematic views showing structure of an apparatus for mounting the solder balls on the wiring board.</li><li><figref idref="f0005">Fig. 5A</figref> is a schematic view explaining positioning of the printed wiring board, and <figref idref="f0005">Fig 5B</figref> is a schematic view explaining supply of solder balls to mounting cylinders.</li><li><figref idref="f0006">Fig. 6A</figref> is a schematic view explaining assembly of solder balls by mounting cylinders, and <figref idref="f0006">Fig. 6B</figref> is a schematic view explaining assembly and guidance of solder balls by the mounting cylinders.</li><li><figref idref="f0007">Fig. 7A</figref> is a schematic view explaining dropping solder balls to connecting pads, and <figref idref="f0007">Fig. 7B</figref> is a schematic view explaining removal of solder balls by adsorbed-ball removing cylinder.</li><li><figref idref="f0008">Fig. 8</figref> is a schematic view explaining maximum surface roughness of the solder resist layer surface.</li><li><figref idref="f0008">Fig. 9</figref> is a schematic view explaining relation between bump height (H) and solder resist layer opening diameter (D) according to the present invention.</li><li><figref idref="f0009">Figs. 10A to 10B</figref> are schematic views explaining unevenness of the filled via surface as a connecting pad.</li><li><figref idref="f0009">Figs. 11A to 11B</figref> are schematic views explaining connecting pad region.</li></ul>

Best Mode for Carrying Out the Invention

0022One embodiment of the printed wiring board according to the present invention will be described hereinafter. In the printed wiring board, as shown in <figref idref="f0008">Fig. 9</figref>, at least one opening is provided in a solder resist layer (SR layer) formed on the outermost layer of a wiring board, a part of the conductor circuit exposed from the at least one opening is formed as connecting pads, the connecting pads are arranged with a pitch of 200 <i>µ</i>m or less, and solder bumps are formed on the respective connecting pads, a ratio (H/D) of a height H from the solder resist layer surface of the solder bump formed on the connecting pad to the opening diameter D is within a range of 0.55 to 1.0.

0023In the embodiment of the present invention, for forming the respective solder bumps in the corresponding openings provided in the solder resist layer, it is desirable to use a novel method and a device for dropping solder balls having very fine particle diameter on the connecting pads through the corresponding openings of a ball aligning mask as described below, without employing a printing method with the use of a conventional mask.

0024First, a novel solder ball mounting method and a device thereof are used for manufacturing. As to the printed wiring board of the present invention, the construction of one embodiment is explained by referring to <figref idref="f0001">Fig. 1</figref> and <figref idref="f0002">Fig. 2</figref>.

0025<figref idref="f0001">Fig. 1</figref> shows a sectional view of a printed wiring board 10, and <figref idref="f0002">Fig. 2</figref> shows a state in which an IC chip 90 is mounted on the printed wiring board 10 and the printed wiring board 10 is mounted on a daughter board 94. As shown in <figref idref="f0001">Fig. 1</figref>, the printed wiring board 10 has a conductor circuit 34 formed on both surfaces of a core substrate 30, and the respective conductor circuits are electrically connected through a plated through hole 36.

0026Further, on the conductor circuit 34 of the core substrate 30 is formed a conductor circuit 58 forming a conductor circuit layer through an interlaminar insulative resin layer 50. The conductor circuit 58 is connected to the conductor circuit 34 through via hole 60. On the conductor circuit 58 is formed a conductor circuit 158 through an interlaminar insulative resin layer 150. The conductor circuit 158 is connected to the conductor circuit 58 through a via hole 160 formed in an interlaminar insulative resin layer 150.

0027A solder resist layer 70 is formed by covering the conductor circuit 158 and the via hole 160, and a connecting pad 75 is formed by forming a nickel plated layer 72 and a gold plated layer 74 on an opening 70 provided in the solder resist layer 71. On the connecting pad 75 of the top face is formed a solder bump 78U and on the connecting pad 75 of the bottom face is formed a BGA (ball grid array) 78D.

0028As shown in <figref idref="f0002">Fig. 2</figref>, the solder bump 78U on the top face side of the printed wiring board 10 is connected to an electrode 92 of the IC chip 90 to form an IC mounted printed wiring board, and the IC mounted printed wiring board is connected to a land 96 of a daughter board 94 through the BGA 78D.

0029Further, it is desirable that the surface of the solder resist layer corresponding to at least electronic parts mounting region is flattened. The solder resist layer and the solder bump are different in thermal expansion coefficient, so that there are produced repeatedly contraction and expansion at the boundary vicinity between the solder bump and the solder resist layer. And, when large unevenness is existent on the solder resist layer surface, i.e. less flatness, the volume of the solder resist layer in the bump vicinity is small to be easily broken. Therefore, by making flatness of the solder resist layer surface small to some extent, the volume of the solder resist layer where large stress is applied to is increased, bending portion where stress tends to concentrate is lessened, and heat cycle resistance can easily be improved.

0030The flattened surface of the solder resist layer is desirably 0.8 to 3.0 µm in maximum surface roughness. The reason is if the maximum surface roughness is within a range of 0.8 to 3.0 µm, crack is hardly generated in the solder resist in the vicinity of the conductor pad, and air (void) is hard to enter into the under fill resin. As a result, insulation reliability and connection reliability are improved.

0031Further, in the embodiment of the present invention, it is desirable to further apply a roughening treatment to the flattened surface of the solder resist layer.

0032Wettability of the under fill resin is easily improved by applying the roughening treatment to the surface of the solder resist layer flattened to some extent, so that under fill resin can be filled in a narrow gap portion in the boundary vicinity between the solder resist layer and the solder bump so as to improve connection reliability.

0033It is desirable that the roughened surface of the solder resist layer is smaller than the maximum surface roughness of the flattened surface and 0. 2 to 0.5 µm at an arithmetic mean roughness (Ra).

0034The reason is that when the arithmetic mean roughness Ra is made within a range of 0.2 to 0.5 µm, adhesion to the under fill resin can be increased, and flux residue and cleaning residue are hardly remained on the solder resist surface. As a result, insulation reliability and connection reliability are easily improved.

0035In the embodiment of the present invention, as understood from <figref idref="f0001">Fig. 1</figref> and <figref idref="f0002">Fig. 2</figref>, among the connecting pads 75 provided on the surface of the substrate as conductor pads for mounting electronic parts, two connecting pads positioned at the center are formed in the form of a land right above the viahole 160, two connecting pads adjacent thereto are formed in the form of pads adjacent to the land of the viahole 160, and further two connecting pads positioned at both ends are formed in the form of a pad consisting of a part of a wiring pattern of the conductor circuit 158.

0036Further, among the connecting pads 75 of the bottom face, two connecting pads positioned at both ends are formed in the form of a land right above the viahole 160, and four connecting pads positioned at the center are formed in the form of a pad adjacent to a land of the viahole 160.

0037The viahole 160 as a connecting pad formed by the solder bump 78U is preferably a filled via, and the uneven amount of the filled via surface exposed from the surface of the interlaminar insulative resin layer 150 is, as shown in <figref idref="f0009">Figs. 10A to 10B</figref>, desirably within a range of -5 µm to +5 µm in relation to the surface thickness of the conductor circuit 158. The reason why the depressed or protruded amount of the filled via surface is restricted to a mentioned above is due to the fact that when the depressed amount is more than 5 µm (-5 µm), the number of contact point defined by the solder ball and the connecting pad consisting of the filled via is reduced, wettability becomes poor in case of forming the solder bump, and entanglement of voids within the bump and missing bump are not controlled, while when the protruded amount of the filled via surface is more than 5 µm(+ 5 µm), the thickness of the conductor circuit 158 becomes too large to be adaptable for fine pitched patterning.

0038Further, the "electronic parts mounting region" in the embodiment of the invention substantially corresponds to a region (hereinafter, simply called as "connecting pad region") where conductor pads such as filled via and the like for mounting electronic parts are provided.

0039For example, <figref idref="f0009">Fig. 11A</figref> shows a state of aligning all of the outermost peripheral connecting pads along each side of a rectangle among grid-like aligned connecting pads, and <figref idref="f0009">Fig. 11B</figref> shows a state of not aligning some of the outermost peripheral connecting pads along each side of the rectangle, however, in either case, when the connecting pad region is made rectangle, a rectangle region determined to minimize an area of the region enclosing all connecting pads is called as "connecting pad region".

0040<figref idref="f0003">Figs. 3A to 3C</figref> are views explaining the steps for forming the solder bumps on the printed wiring board 10 according to the present invention.

0041First, a flux layer 80 is formed for covering conductor pads formed in the openings 71 provided in the solder resist layer 70 on the top face side of the printed wiring board, i.e. the connecting pads 75 by a printing method (see <figref idref="f0003">Fig. 3A</figref>).

0042Next, on the connecting pads 75 on the top face side of the printed wiring board are mounted very small solder balls 78s (for example, made by Hitachi Metals or Tamura) with the use of a solder ball loader described later on (see <figref idref="f0003">Fig. 3B</figref>). Such solder ball is desirable 40 µm or more and less than 200 µm in diameter. When the diameter is less than 40 µm, each solder ball does not easily drop on the corresponding connecting pad because it is light in weight, while when the diameter is 200 µm or more, solder balls are not assembled in a cylinder member, causing the presence of connecting pads with no solder balls mounted thereon. In order to match for the fine patterning, the solder ball having a diameter of 80 µm or less is desirable.

0043Thereafter, solder balls 78L of a usual diameter (250 µm) are adsorbed and placed on the connecting pads 75 on the bottom face side of the printed wiring board with the use of an adsorption head as described in <patcit id="pcit0002" dnum="JP1975429A"><text>Japanese Patent No. 1975429</text></patcit>, for instance (see <figref idref="f0003">Fig. 3C</figref>).

0044Next, by heating in a reflow furnace to form, 500 pieces to 30,000 pieces of the solder bumps 78U are formed with a pitch of 60 to 200 µm on the top face side of the printed wiring board 10 as shown in <figref idref="f0001">Fig. 1</figref>, and 250 pieces of BGA 78D are formed with a pitch of 2 mm on the bottom face side thereof, for instance.

0045The pitch of the solder bumps corresponds to a pitch of the connecting pads, and when the pitch of the connecting pads is less than 60 µm, manufacture of solder balls suitable for the pitch becomes difficult. When the pitch of the connecting pads is more than 200 µm, it becomes impossible to obtain a printed wiring board adaptable for fine patterning or narrow pitching.

0046Further, as shown in <figref idref="f0002">Fig. 2</figref>, an IC mounted printed wiring board 10 is formed by mounting the IC chip 90 through the solder bumps 78U by reflowing, and this IC mounted printed wiring board 10 is mounted on the daughter board 94 through BGA 78D.

0047Next, the solder ball loader for mounting the very small solder balls 78s on the corresponding connecting pads of the above-described printed wiring board is explained by referring to <figref idref="f0004">Figs. 4A to 4B</figref>.

0048<figref idref="f0004">Fig. 4A</figref> is a block diagram showing the structure of the solder ball loader, and <figref idref="f0004">Fig. 4B</figref> is a view taken from an arrow B of the solder ball loader of <figref idref="f0004">Fig 4A</figref>.

0049The solder ball loader 20 comprises an XYθ suction table 14 for positioning and holding the printed wiring board 10, a vertical moving shaft 12 for moving the XYθ suction table 14 up and down, a ball aligning mask 16 with an opening corresponding to the connecting pad 75 of the printed wiring board, a mounting cylinder (cylinder member) 24 for guiding the solder balls moving on the ball aligning mask 16, a suction box 26 for giving negative pressure to the mounting cylinder 24, a solder ball removing cylinder 61 for recovering excessive solder balls, a suction box 66 for giving negative pressure to the solder ball removing cylinder 61, an adsorbed ball removing and adsorbing device 68 for holding the collected solder balls, a mask clamp 44 for clamping the ball aligning mask 16, an X-axis direction moving shaft 40 for sending the mounting cylinder 24 and the solder ball removing cylinder 61 to the X-axis direction, a moving shaft supporting guide 42 for supporting the X-axis direction moving shaft 40, an alignment camera 46 for taking an image of the multilayer printed wiring board 10, a residue detecting sensor 18 for detecting residual amount of the solder balls under the mounting cylinder 24 and a solder ball supplier 22 for supplying solder balls to the side of the mounting cylinder 24 based on the residue detected by the residue detecting sensor 18.

0050A plurality of the mounting cylinders 24 and the solder ball removing cylinder 61 are arranged in the Y-axis direction by corresponding to size of the connecting pad regions. Further, the size may correspond to a plurality of the connecting pad areas. Here, the Y-axis direction is expedient and may be aligned in the X-axis direction. The XYθ suction table 14 functions as positioning, adsorption, maintenance and correction of the solder ball mounted printed wiring board 10. The alignment camera 46 detects an alignment mark of the printed wiring board 10 on the XYθ suction table 14 to regulate a position between the printed wiring board 10 and the ball aligning mask 16 based on the detected position. The residue detecting sensor 18 detects the residue of the solder balls by an optical method.

0051Next, a process for mounting the solder balls by the solder ball loader 20 is explained by referring to <figref idref="f0005 f0006 f0007">Figs. 5 to 7</figref>.

(1) Position recognition and correction of the printed wiring board

0052As shown in <figref idref="f0005">Fig 5A</figref>, an alignment mark 34M of the printed wiring board 10 is recognized by the alignment camera 46, and the position of the printed wiring board 10 in relation to the ball aligning mask 16 is corrected by the suction table 14. That is, openings 16a of the ball aligning mask 16 are adjusted for corresponding to the connecting pads 75 of the printed wiring board 10 in position, respectively. In addition, here, for the reason of illustrating convenience, only one sheet size of the printed wiring board 10 is shown, but actually, solder balls are mounted to a printed wiring board of worksheet size for constructing a plurality of printed wiring boards, and after forming solder bumps, the worksheet size board is cut into respective multilayer printed wiring boards.

(2) Solder balls and supply thereof

0053As shown in <figref idref="f0005">Fig. 5B</figref>, quantitative solder balls 78s are supplied from a solder ball supplying device 22 to the side of the mounting cylinder 24. Here, as the solder ball, any commercial item (a product of Hitachi Metals, for example) may be used or, solder balls may be manufactured according to the manufacturing device and method described in <patcit id="pcit0003" dnum="JP2001226705A"><text>Japanese unexamined patent application No. 2001-226705</text></patcit>.

0054After manufactured, such solder balls are placed on a metal plate (e.g. nickel plate of 25 <i>µ</i>m thick) having a square slit (opening) of which length and breadth are smaller than a designated diameter of the solder ball by 1 µm, and the solder balls are rolled thereon and dropped from the slit. Then, small balls having smaller diameters than designated are removed. Thereafter, the solder balls remained on the metal plate are classified by a metal plate having a square slit of which length and breadth are larger than the desired diameter of the solder ball by 1 µm, and solder balls dropped from the slit are collected so as to obtain the solder balls having a substantially equal diameter to the desired diameter.

(3) Loading of solder balls

0055As shown in <figref idref="f0006">Fig. 6A</figref>, on the upper part of the ball aligning mask 16 is positioned the mounting cylinder 24 by keeping predetermined clearance (e.g. 50% to 300% of a ball diameter), solder balls 78s are assembled on the ball aligning mask 16 right under the opening 24A of the mounting cylinder 24 by adsorbing air from the suction portion 24B at a running speed of 5 m/sec to 35 m/sec in a gap between the mounting cylinder and the printed wiring board.

0056Thereafter, as shown in <figref idref="f0006">Fig. 6B</figref> and <figref idref="f0007">Fig.7A</figref>, the mounting cylinders 24 aligned along the Y-axis of the printed wiring board 10 are sent to the horizontal direction along the X-axis by means of the X-axis direction moving shaft 40. Thereby, the solder balls 78s assembled on the ball aligning mask 16 are moved with the movement of the mounting cylinder 24, dropped to the corresponding connecting pads 75 of the printed wiring board 10 through the openings 16a of the ball aligning mask 16 and loaded. Thereby, the solder balls 78s are successively aligned on the whole connecting pads on the side of the printed wiring board 10.

(4) Removal of the solder ball

0057As shown in <figref idref="f0007">Fig. 7B</figref>, the excessive solder balls 78s are guided to a place having no opening 16a on the ball aligning mask 16, then adsorbed and removed by the solder ball removing cylinder 61.

(5) Substrate removal

0058Then, the printed wiring board 10 is removed from the suction table 14.

0059According to the solder ball loading method and the solder ball loader 20 as explained in the above, the solder balls 78s are assembled by positioning the mounting cylinder 24 on the upper part of the ball aligning mask 16 and adsorbing air from the suction portion 24B on the top of the mounting cylinder 24, the assembled solder balls 78s are moved on the ball aligning mask 16 by moving the mounting cylinder 24 in the horizontal direction, and the solder balls 78s can be dropped to the respective connecting pads 75 of the printed wiring board 10 through the respective openings 16a of the ball aligning mask 16.

0060Therefore, fine solder balls 78s can certainly be mounted on the whole of the connecting pads 75 of the printed wiring board 10. Further, since the solder balls 78s can be moved with no contact, the solder balls can be mounted on the connecting pads 75 without damage, which is different from a printing method with the use of a conventional squeeze, and the solder bumps 78U can be equalized in height.

0061Therefore, according to the above-described method, there are provided excellent mountability of electronic parts such as IC and the like, heat cycle test after the mounting and environment resistance test such as high temperature-high humidity test and the like.

0062Further, without depending on flatness of products, even printed wiring board having much undulated surface can place solder balls appropriately on the connecting pads.

0063Further, as the fine solder balls could certainly be placed on the connecting pads, even in the printed wiring board having such a narrow pitch alignment that the connecting pad pitch is 60 to 200 µm and the solder resist opening diameter is 40 to 150 µ m, in the whole of bumps, stable bumps having substantially uniform heights can be formed.

0064Further, the solder balls are guided by suction force so as to prevent aggregation and adhesion of solder balls. Further, adjusting number of the mounting cylinder 24 so as to be applied to many forms and small production enables the applicability to various sizes of the works (multilayer printed wiring board of work sheet size).

0065In the solder ball loader as described above, the mounting cylinders 24 are aligned in the Y direction by corresponding to width of the work (printed wiring board of work sheet size), so that the solder balls can positively be mounted on the whole of connecting pads 75 of the printed wiring boards by simply sending a plurality of mounting cylinders 24 to the vertical direction (X direction) in relation to the row direction.

0066Further, the solder balls 78s remained on the ball aligning mask 16 can be collected by the solder ball removing cylinder 61, so that there are no problem such that excessive solder ball are remained to cause any trouble and the like.

0067With the use of the above-described solder ball loading method and device, the solder balls mounted on the connecting pads of the wiring substrate become solder bumps having predetermined height by means of a reflow treatment, IC chips are mounted on the substrate through such solder bumps, and the printed wiring board according to the present invention is manufactured.

(Example 1)

(1) Manufacture of printed wiring board

0068As starting material, a double sided copper-clad laminate (e.g. "MCL-E-67" made by Hitachi Chemical) is used, and on this substrate are formed a through-hole conductor and a conductor circuit by a known method. Thereafter, insulating layers and conductor circuit layers are alternately laminated by a known method (e.g. described in a publication entitled "<nplcit id="ncit0001" npl-type="b"><text>Build-up Multilayer Printed Wiring Board" (Kiyoshi Takagi) published by Nikkan Kogyo Shinbunsha on June 20, 2000</text></nplcit>), and in the outermost conductor circuit layer, a group of connecting pads for mounting an IC chip having a grid-like arrangement having thickness: 20 µm, diameter (conductor pad diameter): 150 µm, pitch: 200 µm, number: 50 x 40 (pieces) is formed within a connecting pad region of 150 mm².

0069An area of the region for forming these connecting pads was 150 mm². Such connecting pads are formed by a method similar to that described in <patcit id="pcit0004" dnum="JP2000357762A"><text>Japanese unexamined patent application No. 2000-357762</text></patcit>.

0070Further, in case of changing size, pitch, number and arrangement of connecting pad, the pattern (opening diameter, pitch, arrangement, etc.) of a plated resist is changed.

0071Formation of a solder resist layer is that screen printing is carried out under the following printing condition with the use of a commercial solder resist to form a solder resist layer having a thickness of 15 to 25 µm (on the connecting pad) for covering the connecting pad.

(Printing condition)

0072<tables id="tabl0001" num="0001"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="30mm" /><colspec colnum="2" colname="col2" colwidth="50mm" /><tbody><row><entry>Solder resist ink :</entry><entry>"RPZ-1" made by Hitachi Kogyo</entry></row><row><entry>Ink viscosity :</entry><entry>45±15 Pa·s</entry></row><row><entry>Screen :</entry><entry>polyester fiber (130 to 300 mesh)</entry></row><row><entry>Squeeze speed :</entry><entry>100 to 200 mm/sec</entry></row></tbody></tgroup></table></tables>

0073In this embodiment, thickness of the solder resist layer is 25 µm.

0074Thereafter, a photo mask having a pattern (mask pattern) of opening of solder resist thereon is exposed to ultraviolet ray of 100 to 1000 mJ under the state of adhering to the solder resist layer, and developed with a sodium carbonate solution (Na₂CO₃) of 10 g/L, thereby forming an opening of 120 µm in diameter on the connecting pad.

(2) Mounting of solder balls

0075After applying commercial rozin flux to the surface (IC mounting face) of the printed wiring board manufactured in the above (1), solder balls are loaded on the suction table of a solder ball loader, alignment marks of the printed wiring board and the ball aligning mask are recognized by using a CCD camera, and alignment of the printed wiring board and the ball aligning mask is carried out.

0076Here, as the ball aligning mask, a metal mask made of Ni is used having openings of 175 µm in diameter at the position corresponding to the connecting pads of the printed wiring board.

0077It is also possible to use ball aligning masks made of SUS and polyimide.

0078Further, an opening diameter formed in the ball aligning mask is preferably 1.1 to 1.5 times the ball diameter used, and a thickness of the ball aligning mask is preferably 1/2 to 3/4 of the diameter of the solder ball used.

0079Next, the mounting cylinder of 200 mm in height with a size (1.2 to 3 times to the connecting pad region) corresponding to the connecting pad region is positioned on the metal mask (ball aligning mask) by keeping clearance of 2 times the solder ball diameter, and solder balls (made by Hitachi Metals) of 145 µm in diameter consisting of Sn/Pb solder (Sn/Pb=63:37) are mounted on the peripheral vicinity of the mask.

0080In this example, Sn/Pb is used for the solder ball, use may be made of Pb free solder consisting of at least one metal and Sn selected from the group of Ag, Co, In, Bi, Zn and the like. Further, air is adsorbed from the top of the mounting cylinder, and the gap running speed between the mounting cylinder and the printed wiring board is regulated to 5 to 35 m/sec for assembling the solder balls within the mounting cylinder.

0081Thereafter, the mounting cylinder is moved at 10 to 40 mm/sec of the moving speed to roll the solder balls, and the solder balls are dropped from the respective openings of the ball aligning mask and mounted on the corresponding connection pads.

(3) Formation of solder bump

0082Further, after removing excessive solder balls on the ball aligning mask, the solder ball aligning mask and the printed wiring board are separately taken out of the solder ball loader, and finally, the printed wiring board is put in the reflowing apparatus set at 230°C to form a solder bump.

0083After forming the solder bump, a height of the solder bump protruded from the solder resist surface is measured by a laser microscope ("VX-8500" made by KEYENCE or "WYKO NT-2000" made by Veeco).

0084Further, measurement points are four corners and a center of a rectangle, i.e. four solder bumps located at the four corners of a rectangle defined by the connecting pad group and a solder bump substantially positioned at the center of the rectangle are measured at this time, and five solder balls in total are measured. As a result, the minimum value of the solder bump height is 66 µ m and the maximum value thereof is 70 µm.

(4) Mounting of IC chip

0085After measured the height of each solder bump, an IC chip is mounted through the solder bumps, and an IC chip mounted printed wiring board is manufactured by filling a commercial under fill resin between the IC chip and the solder resist.

(Example 2)

0086Except that the printing condition (mesh of the screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 20 µm and the solder ball having a diameter of 140 µm is mounted with the use of the ball aligning mask having an opening diameter of 160 µm, a printed wiring boards is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 63 µm and the maximum value thereof becomes 68 µm.

(Example 3)

0087Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 15 µm and the solder ball having a diameter of 135 µm is mounted with the use of the ball aligning mask having an opening diameter of 155 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 65 µm and the maximum value thereof becomes 70 µm.

(Example 4)

0088Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 10 µm and the solder ball having a diameter of 130 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 66 µm and the maximum value thereof becomes 68 µm.

(Example 5)

0089Except that the pattern of the plating resist is changed to change connecting pad diameter: 120 µm and pitch: 150 µm, the mask pattern of a photo mask in case of forming a solder resist opening is changed to change the solder resist opening diameter to 90 µm, the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 10 µm and the solder ball having a diameter of 90 µm is mounted with the use of the ball aligning mask having an opening diameter of 110 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 46 µm and the maximum value thereof becomes 49 µm.

(Example 6)

0090Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 15 µm, and the solder ball having a diameter of 95 µm is mounted with the use of the ball aligning mask having an opening diameter of 115 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 45 µm and the maximum value thereof becomes 49 µm.

(Example 7)

0091Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 20 µm and the solder ball having a diameter of 100 µm is mounted with the use of the ball aligning mask having an opening diameter of 120 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 47 µm and the maximum value thereof becomes 49 µm.

(Example 8)

0092Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 25 µm and the solder ball having a diameter of 105 µm is mounted with the use of the ball aligning mask having an opening diameter of 130 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 47 µm and the maximum value thereof becomes 48 µm.

(Example 9)

0093Except that the pattern of the plating resist is changed to change connecting pad diameter: 80 µm and pitch: 100 µm, the mask pattern of the photo mask in case of forming a solder resist opening is set to change the solder resist opening diameter to 60 µm, the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 10 µm and the solder ball having a diameter of 50 µm is mounted with the use of the ball aligning mask having an opening diameter of 60 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 31 µm and the maximum value thereof becomes 34 µm.

(Example 10)

0094Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 15 µm and the solder ball having a diameter of 55 µm is mounted with the use of the ball aligning mask having an opening diameter of 70 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 33 µm and the maximum value thereof becomes 34 µm.

(Example 11)

0095Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 20 µm and the solder ball having a diameter of 60 µm is mounted with the use of the ball aligning mask having an opening diameter of 70 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 33 µm and the maximum value thereof becomes 35 µm.

(Example 12)

0096Except that the printing condition (mesh of screen and printing speed) of the solder resist is regulated, film thickness of the solder resist is made 25 µm and the solder ball having a diameter of 65 µm is mounted with the use of the ball aligning mask having an opening diameter of 80 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 32 µm and the maximum value thereof becomes 34 µm.

(Example 13)

0097Except that the solder ball having a diameter of 160 µm is mounted with the use of the ball aligning mask having an opening diameter of 190 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 84 µm and the maximum value thereof becomes 87 µm.

(Example 14)

0098Except that the solder ball having a diameter of 155 µm is mounted with the use of the ball aligning mask having an opening diameter of 180 µm, a printed wiring board is manufactured in the same manner as in Example 2. As a result, the minimum value of the solder bump height becomes 83 µm and the maximum value thereof becomes 86 µm.

(Example 15)

0099Except that the solder ball having a diameter of 150 µm is mounted with the use of the ball aligning mask having an opening diameter of 180 µm, a printed wiring board is manufactured in the same manner as in Example 3. As a result, the minimum value of the solder bump height becomes 83 µm and the minimum value thereof becomes 87 µm.

(Example 16)

0100Except that the solder ball having a diameter of 145 µm is mounted with the use of the ball aligning mask having an opening diameter of 170 µm, a printed wiring board is manufactured in the same manner as in Example 4. As a result, the minimum value of the solder bump height becomes 84 µm and the maximum value thereof becomes 86 µm.

(Example 17)

0101Except that the solder ball having a diameter of 100 µm is mounted with the use of the ball aligning mask having an opening diameter of 120 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 63 µm and the maximum value thereof becomes 66 µm.

(Example 18)

0102Except that the solder ball having a diameter of 105 µm is mounted with the use of the ball aligning mask having an opening diameter of 130 µm, a printed wiring board is manufactured in the same manner as in Example 6. As a result, the minimum value of the solder bump height becomes 63 µm and the maximum value thereof becomes 66 µm.

(Example 19)

0103Except that the solder ball having a diameter of 110 µm is mounted with the use of the ball aligning mask having an opening diameter of 140 µm, a printed wiring board is manufactured in the same manner as in Example 7. As a result, the minimum value of the solder bump height becomes 61 µm and the maximum value thereof becomes 67 µm.

(Example 20)

0104Except that the solder ball having a diameter of 115 µm is mounted with the use of the ball aligning mask having an opening diameter of 140 µm, a printed wiring board is manufactured in the same manner as in Example 8. As a result, the minimum value of the solder bump height becomes 61 µm and the maximum value thereof becomes 65 µm.

(Example 21)

0105Except that the solder ball having a diameter of 60 µm is mounted with the use of the ball aligning mask having an opening diameter of 80 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 40 µm and the maximum value thereof becomes 43 µm.

(Example 22)

0106Except that the solder ball having a diameter of 65 µm is mounted with the use of the ball aligning mask having an opening diameter of 85 µm, a printed wiring board is manufactured in the same manner as in Example 10. As a result, the minimum value of the solder bump height becomes 40 µm and the maximum value thereof becomes 43 µm.

(Example 23)

0107Except that the solder ball having a diameter of 70 µm is mounted with the use of the ball aligning mask having an opening diameter of 90 µm, a printed wiring board is manufactured in the same manner as in Example 11. As a result, the minimum value of the solder bump height becomes 41 µm and the maximum value thereof becomes 44 µm.

(Example 24)

0108Except that the solder ball having a diameter of 75 µm is mounted with the use of the ball aligning mask having an opening diameter of 95 µm, a printed wiring boards is manufactured in the same manner as in Example 12. As a result, the minimum value of the solder bump height becomes 42 µm and the maximum value thereof becomes 42 µm.

(Example 25)

0109Except that the solder ball having a diameter of 190 µm is mounted with the use of the ball aligning mask having an opening diameter of 230 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 120 µm and the maximum value thereof becomes 120 µm.

(Example 26)

0110Except that the solder ball having a diameter of 185 µm is mounted with the use of the ball aligning mask having an opening diameter of 230 <i>µ</i>m, a printed wiring board is manufactured in the same manner as in Example 2. As a result, the minimum value of the solder bump height becomes 121 µm and the maximum value thereof becomes 122 µm.

(Example 27)

0111Except that the solder ball having a diameter of 180 µm is mounted with the use of the ball aligning mask having an opening diameter of 220 µm, a printed wiring boards is manufactured in the same manner as in Example 3. As a result, the minimum value of the solder bump height becomes 122 µm and the maximum value thereof becomes 126 µm.

(Example 28)

0112Except that the solder ball having a diameter of 175 µm is mounted with the use of the ball aligning mask having an opening diameter of 200 µm, a printed wiring board is manufactured in the same manner as in Example 4. As a result, the minimum value of the solder bump height becomes 122 µm and the maximum value thereof becomes 123 µm.

(Example 29)

0113Except that the solder ball having a diameter of 125 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 92 µm and the maximum value thereof becomes 94 µm.

(Example 30)

0114Except that the solder ball having a diameter of 130 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 <i>µ</i>m, a printed wiring board is manufactured in the same manner as in Example 6. As a result, the minimum value of the solder bump height becomes 90 µm and the maximum value thereof becomes 93 µm.

(Example 31)

0115Except that the solder ball having a diameter of 135 µm is mounted with the use of the ball aligning mask having an opening diameter of 160 µm, a printed wiring board is manufactured in the same manner as in Example 7. As a result, the minimum value of the solder bump height becomes 91 µm and the maximum value thereof becomes 93 µm.

(Example 32)

0116Except that the solder ball having a diameter of 140 µm is mounted with the use of the ball aligning mask having an opening diameter of 170 µm, a printed wiring board is manufactured in the same manner as in Example 8. As a result, the minimum value of the solder bump height becomes 90 µm and the maximum value thereof becomes 91 µm.

(Example 33)

0117Except that the solder ball having a diameter of 75 µm is mounted with the use of the ball aligning mask having an opening diameter of 90 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 61 µm and the maximum value thereof becomes 63 µm.

(Example 34)

0118Except that the solder ball having a diameter of 80 µm is mounted with the use of the ball aligning mask having an opening diameter of 100 µm, a printed wiring board is manufactured in the same manner as in Example 10. As a result, the minimum value of the solder bump height becomes 60 µm and the maximum value thereof becomes 63 µm.

(Example 35)

0119Except that the solder ball having a diameter of 85 µm is mounted with the use of the ball aligning mask having an opening diameter of 110 µm, a printed wiring board is manufactured in the same manner as in Example 11. As a result, the minimum value of the solder bump height becomes 62 µm and the maximum value thereof becomes 63 µm.

(Example 36)

0120Except that the solder ball having a diameter of 90 µm is mounted with the use of the ball aligning mask having an opening diameter of 120 µm, a printed wiring board is manufactured in the same manner as in Example 12. As a result, the minimum value of the solder bump height becomes 60 µm and the maximum value thereof becomes 61 µm.

(Comparative Example 1)

0121Except that the solder ball having a diameter of 125 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 48 µm and the maximum value thereof becomes 50 µm.

(Comparative Example 2)

0122Except that the solder ball having a diameter of 120 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 µm, a printed wiring board is manufactured in the same manner as in Example 2. As a result, the minimum value of the solder bump height becomes 46 µm and the maximum value thereof becomes 50 µm.

(Comparative Example 3)

0123Except that the solder ball having a diameter of 115 µm is mounted with the use of the ball aligning mask having an opening diameter of 130 µm, a printed wiring board is manufactured in the same manner as in Example 3. As a result, the minimum value of the solder bump height becomes 45 µm and the maximum value thereof becomes 47 µm.

(Comparative Example 4)

0124Except that the solder ball having a diameter of 110 µm is mounted with the use of the ball aligning mask having an opening diameter of 130 µm, a printed wiring board is manufactured in the same manner as in Example 4. As a result, the minimum value of the solder bump height becomes 48 µm and the maximum value thereof becomes 50 µm.

(Comparative Example 5)

0125Except that the solder ball having a diameter of 80 µm is mounted with the use of the ball aligning mask having an opening diameter of 100 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 35 µm and the maximum value thereof becomes 36 µm.

(Comparative Example 6)

0126Except that the solder ball having a diameter of 85 µm is mounted with the use of the ball aligning mask having an opening diameter of 110 µm, a printed wiring board is manufactured in the same manner as in Example 6. As a result, the minimum value of the solder bump height becomes 33 µm and the maximum value thereof becomes 35 µm.

(Comparative Example 7)

0127Except that the solder ball having a diameter of 90 µm is mounted with the use of the ball aligning mask having an opening diameter of 115 µm, a printed wiring board is manufactured in the same manner as in Example 7. As a result, the minimum value of the solder bump height becomes 36 µm and the maximum value thereof becomes 38 µm.

(Comparative Example 8)

0128Except that the solder ball having a diameter of 95 µm is mounted with the use of the ball aligning mask having an opening diameter of 120 µm, a printed wiring board is manufactured in the same manner as in Example 8. As a result, the minimum value of the solder bump height becomes 36 µm and the maximum value thereof becomes 39 µm.

(Comparative Example 9)

0129Except that the solder ball having a diameter of 40 µm is mounted with the use of the ball aligning mask having an opening diameter of 55 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 22 µm and the maximum value thereof becomes 24 µm.

(Comparative Example 10)

0130Except that the solder ball having a diameter of 45 µm is mounted with the use of the ball aligning mask having an opening diameter of 60 µm, a printed wiring board is manufactured in the same manner as in Example 10. As a result, the minimum value of the solder bump height becomes 21 µm and the maximum value thereof becomes 23 µm.

(Comparative Example 11)

0131Except that the solder ball having a diameter of 50 µm is mounted with the use of the ball aligning mask having an opening diameter of 70 µm, a printed wiring board is manufactured in the same manner as in Example 11. As a result, the minimum value of the solder bump height becomes 20 µm and the maximum value thereof becomes 22 µm.

(Comparative Example 12)

0132Except that the solder ball having a diameter of 55 µm is mounted with the use of the ball aligning mask having an opening diameter of 80 µm, a printed wiring board is manufactured in the same manner as in Example 12. As a result, the minimum value of the solder bumper height becomes 24 µm and the maximum value thereof becomes 26 µm.

(Comparative Example 13)

0133Except that the solder ball having a diameter of 220 µm is mounted with the use of the ball aligning mask having an opening diameter of 260 µm, a printed wiring board is manufactured in the same manner as in Example 1. As a result, the minimum value of the solder bump height becomes 155 µm and the maximum value thereof becomes 165 µm.

(Comparative Example 14)

0134Except that the solder ball having a diameter of 215 µm is mounted with the use of the ball aligning mask having an opening diameter of 260 µm, a printed wiring board is manufactured in the same manner as in Example 2. As a result, the minimum value of the solder bump height becomes 100 µm and the maximum value thereof becomes 180 µm.

(Comparative Example 15)

0135Except that the solder ball having a diameter of 210 µm is mounted with the use of the ball aligning mask having an opening diameter of 250 µm, a printed wiring board is manufactured in the same manner as in Example 3. As a result, the minimum value of the solder bump height becomes 150 µm and the maximum value thereof becomes 160 µm.

(Comparative Example 16)

0136Except that the solder ball having a diameter of 205 µm is mounted with the use of the ball aligning mask having an opening diameter of 240 µm, a printed wiring board is manufactured in the same manner as in Example 4. As a result, the minimum value of the solder bump height becomes 112 µm and the maximum value thereof becomes 158 µm.

(Comparative Example 17)

0137Except that the solder ball having a diameter of 155 µm is mounted with the use of the ball aligning mask having an opening diameter of 180 µm, a printed wiring board is manufactured in the same manner as in Example 5. As a result, the minimum value of the solder bump height becomes 88 µm and the maximum value thereof becomes 120 µm.

(Comparative Example 18)

0138Except that the solder ball having a diameter of 160 µm is mounted with the use of the ball aligning mask having an opening diameter of 180 µm, a printed wiring board is manufactured in the same manner as in Example 6. As a result, the minimum value of the solder bump height becomes 120 µm and the maximum value thereof becomes 180 µm.

(Comparative Example 19)

0139Except that the solder ball having a diameter of 165 µm is mounted with the use of the ball aligning mask having an opening diameter of 190 µm, a printed wiring board is manufactured in the same manner as in Example 7. As a result, the minimum value of the solder bump height becomes 120 µm and the maximum value thereof becomes 128 µm.

(Comparative Example 20)

0140Except that the solder ball having a diameter of 170 µm is mounted with the use of the ball aligning mask having an opening diameter of 200 µm, a printed wiring board is manufactured in the same manner as in Example 8. As a result, the minimum value of the solder bump height becomes 75 µm and the maximum value thereof becomes 160 µm.

(Comparative Example 21)

0141Except that the solder ball having a diameter of 105 µm is mounted with the use of the ball aligning mask having an opening diameter of 140 µm, a printed wiring board is manufactured in the same manner as in Example 9. As a result, the minimum value of the solder bump height becomes 80 µm and the maximum value thereof becomes 88 µm.

(Comparative Example 22)

0142Except that the solder ball having a diameter of 110 µm is mounted with the use of the ball aligning mask having an opening diameter of 140 µm, a printed wiring board is manufactured in the same manner as in Example 10. As a result, the minimum value of the solder bump height becomes 40 µm and the maximum value thereof becomes 90 µm.

(Comparative Example 23)

0143Except that the solder ball having a diameter of 115 µm is mounted with the use of the ball aligning mask having an opening diameter of 140 µm, a printed wiring board is manufactured in the same manner as in Example 11. As a result, the minimum value of the solder bump height becomes 80 µm and the maximum value thereof becomes 85 µm.

(Comparative Example 24)

0144Except that the solder ball having a diameter of 120 µm is mounted with the use of the ball aligning mask having an opening diameter of 150 µm, a printed wiring board is manufactured in the same manner as in Example 12. As a result, the minimum value of the solder bump height becomes 75 µm and the maximum value thereof becomes 90 µm.

0145Here, as to the IC mounted printed wiring boards manufactured according to Examples 1 to 36 and Comparative Examples 1 to 24, a test for evaluating heat cycle resistance is conducted as follows.

(Heat cycle resistance)

0146First, there is measured electric resistance (between a pair of connecting pads exposed to the surface opposite to the IC chip mounted surface of the IC mounted printed wiring board and electrically connected to the IC chip) of a specific circuit through IC chips, and its value is determined as an initial value.

0147Thereafter, a heat cycle test under the condition of -55°C (5 minutes) ↔ 125°C 5 minutes) as one cycle is repeated 1000 times to those IC chip mounting printed wiring boards. Electric resistances after 500 cycles and 1000 cycles are measured, respectively, and a rate of change (100 x (measured value - initial value)/initial value (%)) with the initial value is obtained. The case within ±10 is evaluated as "good (O)", and others are evaluated as "no good (x)". This test result is shown in Table 1 and Table 2. <tables id="tabl0002" num="0002"><table frame="all"><title>(Table 1)</title><tgroup cols="12"><colspec colnum="1" colname="col1" colwidth="19mm" /><colspec colnum="2" colname="col2" colwidth="21mm" /><colspec colnum="3" colname="col3" colwidth="21mm" /><colspec colnum="4" colname="col4" colwidth="21mm" /><colspec colnum="5" colname="col5" colwidth="20mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="20mm" /><colspec colnum="8" colname="col8" colwidth="20mm" /><colspec colnum="9" colname="col9" colwidth="21mm" /><colspec colnum="10" colname="col10" colwidth="20mm" /><colspec colnum="11" colname="col11" colwidth="20mm" /><colspec colnum="12" colname="col12" colwidth="21mm" /><thead><row><entry morerows="1" align="center" valign="middle">Examples</entry><entry morerows="1" align="center" valign="middle">Diameter of Connecting Pad (µm)</entry><entry morerows="1" align="center" valign="middle">Pitch of Connecting Pad (µm)</entry><entry morerows="1" align="center" valign="middle">Thickness of Solder Resist Layer (µm)</entry><entry morerows="1" align="center" valign="middle">Opening Diameter of Solder Resist Layer (µm)</entry><entry morerows="1" align="center" valign="middle">Diameter of Solder Ball (µm)</entry><entry morerows="1" align="center" valign="middle">Opening Diameter of Mask (µm)</entry><entry morerows="1" align="center" valign="middle">Height of Bamp (minimum) (µm)</entry><entry morerows="1" align="center" valign="middle">Height of Bamp(Maximum) (µm)</entry><entry morerows="1" align="center" valign="middle">Height of Bamp/ <i>Opening Diameter</i> of SR</entry><entry namest="col11" nameend="col12" align="center" valign="middle">Heat Cycle Test</entry></row><row><entry align="center" valign="middle">500 cycles</entry><entry align="center" valign="middle">1000 cycles</entry></row></thead><tbody><row><entry align="center" valign="middle">Example 1</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">145</entry><entry align="center" valign="middle">175</entry><entry align="center" valign="middle">66</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">0.55</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 2</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">68</entry><entry align="center" valign="middle">0.53</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 3</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">135</entry><entry align="center" valign="middle">155</entry><entry align="center" valign="middle">65</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">0.54</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 4</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">66</entry><entry align="center" valign="middle">68</entry><entry align="center" valign="middle">0.55</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 5</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">46</entry><entry align="center" valign="middle">49</entry><entry align="center" valign="middle">0.51</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 6</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">95</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">45</entry><entry align="center" valign="middle">49</entry><entry align="center" valign="middle">0.50</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 7</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">47</entry><entry align="center" valign="middle">49</entry><entry align="center" valign="middle">0.52</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 8</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">105</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">47</entry><entry align="center" valign="middle">49</entry><entry align="center" valign="middle">0.52</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 9</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">50</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">31</entry><entry align="center" valign="middle">34</entry><entry align="center" valign="middle">0.52</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 10</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">55</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">33</entry><entry align="center" valign="middle">34</entry><entry align="center" valign="middle">0.55</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 11</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">33</entry><entry align="center" valign="middle">35</entry><entry align="center" valign="middle">0.55</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 12</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">65</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">32</entry><entry align="center" valign="middle">34</entry><entry align="center" valign="middle">0.53</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 13</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">190</entry><entry align="center" valign="middle">84</entry><entry align="center" valign="middle">87</entry><entry align="center" valign="middle">0.70</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 14</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">155</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">83</entry><entry align="center" valign="middle">86</entry><entry align="center" valign="middle">0.69</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 15</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">83</entry><entry align="center" valign="middle">87</entry><entry align="center" valign="middle">0.69</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 16</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">145</entry><entry align="center" valign="middle">170</entry><entry align="center" valign="middle">84</entry><entry align="center" valign="middle">86</entry><entry align="center" valign="middle">0.70</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 17</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">66</entry><entry align="center" valign="middle">0.70</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 18</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">105</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">67</entry><entry align="center" valign="middle">0.70</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 19</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">61</entry><entry align="center" valign="middle">67</entry><entry align="center" valign="middle">0.68</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">61</entry><entry align="center" valign="middle">65</entry><entry align="center" valign="middle">0.68</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 21</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">40</entry><entry align="center" valign="middle">43</entry><entry align="center" valign="middle">0.67</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 22</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">65</entry><entry align="center" valign="middle">85</entry><entry align="center" valign="middle">40</entry><entry align="center" valign="middle">43</entry><entry align="center" valign="middle">0.67</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 23</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">41</entry><entry align="center" valign="middle">44</entry><entry align="center" valign="middle">0.68</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 24</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">75</entry><entry align="center" valign="middle">95</entry><entry align="center" valign="middle">42</entry><entry align="center" valign="middle">42</entry><entry align="center" valign="middle">0.70</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 25</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">190</entry><entry align="center" valign="middle">230</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">1.00</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 26</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">185</entry><entry align="center" valign="middle">230</entry><entry align="center" valign="middle">121</entry><entry align="center" valign="middle">122</entry><entry align="center" valign="middle">1.01</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 27</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">220</entry><entry align="center" valign="middle">122</entry><entry align="center" valign="middle">126</entry><entry align="center" valign="middle">1.02</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 28</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">175</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">122</entry><entry align="center" valign="middle">123</entry><entry align="center" valign="middle">1.02</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 29</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">125</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">92</entry><entry align="center" valign="middle">94</entry><entry align="center" valign="middle">1.02</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 30</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">93</entry><entry align="center" valign="middle">1.00</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 31</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">135</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">91</entry><entry align="center" valign="middle">93</entry><entry align="center" valign="middle">1.01</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 32</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">170</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">91</entry><entry align="center" valign="middle">1.00</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 33</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">75</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">61</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">1.02</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 34</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">1.00</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 35</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">85</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">62</entry><entry align="center" valign="middle">63</entry><entry align="center" valign="middle">1.03</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row><row><entry align="center" valign="middle">Example 36</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">61</entry><entry align="center" valign="middle">1.00</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">○</entry></row></tbody></tgroup></table></tables><tables id="tabl0003" num="0003"><table frame="all"><title>(Table 2)</title><tgroup cols="12"><colspec colnum="1" colname="col1" colwidth="19mm" /><colspec colnum="2" colname="col2" colwidth="21mm" /><colspec colnum="3" colname="col3" colwidth="21mm" /><colspec colnum="4" colname="col4" colwidth="22mm" /><colspec colnum="5" colname="col5" colwidth="20mm" /><colspec colnum="6" colname="col6" colwidth="20mm" /><colspec colnum="7" colname="col7" colwidth="20mm" /><colspec colnum="8" colname="col8" colwidth="20mm" /><colspec colnum="9" colname="col9" colwidth="21mm" /><colspec colnum="10" colname="col10" colwidth="20mm" /><colspec colnum="11" colname="col11" colwidth="20mm" /><colspec colnum="12" colname="col12" colwidth="21mm" /><thead><row><entry morerows="1" align="center" valign="middle">Examples</entry><entry morerows="1" align="center" valign="middle">Diameter of Connecting Pad (µm)</entry><entry morerows="1" align="center" valign="middle">Pitch of Connecting Pad (µm)</entry><entry morerows="1" align="center" valign="middle">Thicknes of Solder Resist Layer (µm)</entry><entry morerows="1" align="center" valign="middle">Opening Diameter of Solder Resist Layer (µm)</entry><entry morerows="1" align="center" valign="middle">Diamter of Solder Ball (µm)</entry><entry morerows="1" align="center" valign="middle">Opening Diameter of Solder Resist Layer (µm)</entry><entry morerows="1" align="center" valign="middle">Height of Bamp(minimum) (µm)</entry><entry morerows="1" align="center" valign="middle">height of Bamp (Maximum) (µm)</entry><entry morerows="1" align="center" valign="middle">Height of Bamp/Opening Diameter of SR</entry><entry namest="col11" nameend="col12" align="center" valign="middle">Heat Cycle Test</entry></row><row><entry align="center" valign="middle">500 cycles</entry><entry align="center" valign="middle">1000 cycles</entry></row></thead><tbody><row><entry align="center" valign="middle">Example 1</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">125</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">48</entry><entry align="center" valign="middle">50</entry><entry align="center" valign="middle">0.40</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 2</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">46</entry><entry align="center" valign="middle">50</entry><entry align="center" valign="middle">0.38</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 3</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">45</entry><entry align="center" valign="middle">47</entry><entry align="center" valign="middle">0.38</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 4</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">130</entry><entry align="center" valign="middle">48</entry><entry align="center" valign="middle">50</entry><entry align="center" valign="middle">0.40</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 5</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">35</entry><entry align="center" valign="middle">36</entry><entry align="center" valign="middle">0.39</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 6</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">85</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">33</entry><entry align="center" valign="middle">35</entry><entry align="center" valign="middle">0.37</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 7</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">36</entry><entry align="center" valign="middle">38</entry><entry align="center" valign="middle">0.40</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 8</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">95</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">36</entry><entry align="center" valign="middle">39</entry><entry align="center" valign="middle">0.40</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 9</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">40</entry><entry align="center" valign="middle">55</entry><entry align="center" valign="middle">22</entry><entry align="center" valign="middle">24</entry><entry align="center" valign="middle">0.37</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 10</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">45</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">21</entry><entry align="center" valign="middle">23</entry><entry align="center" valign="middle">0.35</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 11</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">50</entry><entry align="center" valign="middle">70</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">22</entry><entry align="center" valign="middle">0.33</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 12</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">55</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">24</entry><entry align="center" valign="middle">26</entry><entry align="center" valign="middle">0.40</entry><entry align="center" valign="middle">○</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 13</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">220</entry><entry align="center" valign="middle">260</entry><entry align="center" valign="middle">155</entry><entry align="center" valign="middle">165</entry><entry align="center" valign="middle">1.29</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 14</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">215</entry><entry align="center" valign="middle">260</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">0.83</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 15</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">210</entry><entry align="center" valign="middle">250</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">1.25</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 16</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">205</entry><entry align="center" valign="middle">240</entry><entry align="center" valign="middle">112</entry><entry align="center" valign="middle">158</entry><entry align="center" valign="middle">0.93</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 17</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">155</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">88</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">0.98</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 18</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">180</entry><entry align="center" valign="middle">1.33</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 19</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">165</entry><entry align="center" valign="middle">190</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">1.28</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 20</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">170</entry><entry align="center" valign="middle">200</entry><entry align="center" valign="middle">76</entry><entry align="center" valign="middle">160</entry><entry align="center" valign="middle">0.84</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 21</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">10</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">105</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">88</entry><entry align="center" valign="middle">1.33</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 22</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">15</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">110</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">40</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">0.67</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 23</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">20</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">115</entry><entry align="center" valign="middle">140</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">85</entry><entry align="center" valign="middle">1.33</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row><row><entry align="center" valign="middle">Example 24</entry><entry align="center" valign="middle">80</entry><entry align="center" valign="middle">100</entry><entry align="center" valign="middle">25</entry><entry align="center" valign="middle">60</entry><entry align="center" valign="middle">120</entry><entry align="center" valign="middle">150</entry><entry align="center" valign="middle">75</entry><entry align="center" valign="middle">90</entry><entry align="center" valign="middle">1.25</entry><entry align="center" valign="middle">X</entry><entry align="center" valign="middle">X</entry></row></tbody></tgroup></table></tables>

0148Next, as to Examples 2, 7, 11, 14, 19, 23, 26, 31 and 35 among Examples 1 to 36, after forming a solder resist layer, printed wiring boards made by applying the following flattening treatment to the solder resist layer surface are manufactured, and these are denoted as Examples 37 to 45.

(Example 37)

0149Except that the following flattening treatment is applied to the solder resist layer surface after forming the resist layer, a printed wiring board is manufactured in the same manner as in Example 2.

(Flattening treatment)

0150First, on the solder resist layer surface, a connecting pad region for mounting IC chip (region area: 1200 mm², connecting pad number: 30000) is measured by means of a surface roughness measuring instrument (e.g. "SURFCOM 480A" made by Tokyo Seimitsu or "WYKO N-2500" by Veeco) to examine uneven amount (see <figref idref="f0008">Fig, 8</figref>) due to the presence or absence of conductor pads. As a result, the uneven amount of the solder resist layer surface becomes 7.2 to 9.8 µ m.

0151Next, a polyethylene terephthalate (PET) film is applied on the surface of the solder resist layer, and the solder resist surface is flattened by applying pressure to the solder resist layer through the polyethylene terephthalate film under the following flattening treatment condition.

(Flattening treatment condition)

0152<tables id="tabl0004" num="0004"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0153On the surface of the solder resist layer after flattening treatment, the same region as that already measured is measured by the same surface roughness measuring instrument, a degree of unevenness of the solder resist layer surface after flattening treatment is examined. As a result, an amount of unevenness of the flattened surface of the solder resist layer becomes small to about 0.8 (minimum uneven amount) to 3.2 µm (maximum uneven amount).

0154In addition, "maximum uneven amount" and "minimum uneven amount" mentioned herein mean, as shown in <figref idref="f0008">Fig. 8</figref>, maximum value and minimum value of differences X1, X2, X3, X4, X5 · · · · between height of the solder resist layer on the conductor pad or conductor circuit and that of the solder resist layer of adjacent conductor pad non-forming part or conductor circuit non-forming part in the electronic part mounting region.

(Example 38)

0155Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 7.

(Flattening treatment condition)

0156<tables id="tabl0005" num="0005"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0157An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively as large as about 6.6 to 10.2 µm, but the amount of the flattened surface is as small as about 0.7 to 3.0 µm.

(Example 39)

0158Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 11.

(Flattening treatment condition)

0159<tables id="tabl0006" num="0006"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0160An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively as large as about 8.4 to 9.3 µm, but that of the flattened surface is as small as about 0.8 to 3.1 µm.

(Example 40)

0161Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 14.

(Flattening treatment condition)

0162<tables id="tabl0007" num="0007"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0163An uneven amount of the surface before flattening the solder resist layer obtained in this example is large such as about 8.2 to 9.6 µm, but that of the flattened surface is small such as about 0.7 to 3.2 µm.

(Example 41)

0164Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 19.

(Flattening treatment condition)

0165<tables id="tabl0008" num="0008"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0166An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively as large as about 9.9 to 10.2 µm, but that of the flattened surface is as small as about 0.8 to 3.3 µm.

(Example 42)

0167Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 23.

(Flattening treatment condition)

0168<tables id="tabl0009" num="0009"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0169An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively large such as about 8.3 to 10.3 µm, but that of the flattened surface is small such as about 0.7 to 3.0 µm.

(Example 43)

0170Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 26.

(Flattening treatment condition)

0171<tables id="tabl0010" num="0010"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0172An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively large such as about 9.1 to 9.8 µm. but that of the flattened surface is small such as about 0.5 to 3.1 µm.

(Example 44)

0173Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 31.

(flattening treatment condition)

0174<tables id="tabl0011" num="0011"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0175An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively large such as about 8.1 to 10.2 µm, but that of the flattened surface is small such as about 0.8 to 3.0 µm.

(Example 45)

0176Except that after forming a solder resist layer, flattening treatment is applied to the solder resist layer surface with the following condition, a printed wiring board is manufactured in the same manner as in Example 35.

(Flattening treatment condition)

0177<tables id="tabl0012" num="0012"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="32mm" /><colspec colnum="2" colname="col2" colwidth="24mm" /><tbody><row><entry>Press temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Press pressure:</entry><entry>3 to 5 MPa</entry></row><row><entry>Press time:</entry><entry>1 to 3 minutes</entry></row></tbody></tgroup></table></tables>

0178An uneven amount of the surface before flattening the solder resist layer obtained in this example is comparatively large such as about 9.6 to 10.3 µm, but that of the flattened surface is small such as about 0.7 to 3.0 µm.

0179As to flattened IC mounted printed wiring boards manufactured according to Examples 37 to 45, the same heat cycle test as in Examples 1 to 36 is carried out, electric resistance after 1000 cycles and after 1500 cycles is measured, and a rate of change (100 x (measured value - initial value)/initial value (%)) with the initial value is obtained. The case within ±10 is evaluated as "good (O) " and the other cases are evaluated as "no good (x)". This test result is shown in Table 3.

0180In addition, as to the IC mounted printed wiring boards manufactured according to Examples 2, 7, 11, 14, 19, 23, 26, 31 and 35 applied no flattening treatment, the same heat cycle test is carried out, a rate of change of electric resistance is obtained and evaluated. These test results are also shown in Table 3 with the test results of Examples 37 to 45. <tables id="tabl0013" num="0013"><table frame="all"><title>(Table 3)</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="28mm" /><colspec colnum="2" colname="col2" colwidth="49mm" /><colspec colnum="3" colname="col3" colwidth="49mm" /><colspec colnum="4" colname="col4" colwidth="20mm" /><colspec colnum="5" colname="col5" colwidth="21mm" /><thead><row><entry morerows="1" align="center" valign="middle">Examples</entry><entry namest="col2" nameend="col3" align="center" valign="middle">Amount of unevenness of Flattened Surface of Solder Resist Layer (µm)</entry><entry namest="col4" nameend="col5" align="center" valign="middle">Heat Cycle Test</entry></row><row><entry align="center" valign="middle">Minimum Amount</entry><entry align="center" valign="middle">Maximum Amount</entry><entry align="center" valign="middle">500 cycles</entry><entry align="center" valign="middle">1000 cycles</entry></row></thead><tbody><row><entry align="center" valign="middle">Example 37 (2)</entry><entry align="center" valign="middle">0.8</entry><entry align="center" valign="middle">3.2</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 38 (7)</entry><entry align="center" valign="middle">0.7</entry><entry align="center" valign="middle">3.0</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 39 (11)</entry><entry align="center" valign="middle">0.8</entry><entry align="center" valign="middle">3. 1</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 40 (14)</entry><entry align="center" valign="middle">0.7</entry><entry align="center" valign="middle">3.2</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 41 (19)</entry><entry align="center" valign="middle">0.8</entry><entry align="center" valign="middle">3.3</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 42 (23)</entry><entry align="center" valign="middle">0.7</entry><entry align="center" valign="middle">3.0</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 43 (26)</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">3.1</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 44 (31)</entry><entry align="center" valign="middle">0.8</entry><entry align="center" valign="middle">3.0</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 45 (35)</entry><entry align="center" valign="middle">0.7</entry><entry align="center" valign="middle">3.0</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row></tbody></tgroup></table></tables>

0181Then, as to the IC mounted printed wiring boards manufactured according to Examples 37 to 45, in which the solder resist layer surface is flattened, their flattened substrates are further roughened with the following condition, thereby manufacturing IC mounted printed wiring boards formed with fine uneven faces (roughened faces) on the flattened surface of the solder resist layer, and these are made Examples 46 to 54.

(Example 46)

0182Except that roughening treatment is applied to the solder resist layer surface with the following condition after flattening, a printed wiring board is manufactured in the same manner as in Example 37.

(Roughening condition)

0183<tables id="tabl0014" num="0014"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0184After roughening treatment, surface roughness of the solder resist surface is randomly measured at 10 spots by surface roughness measuring instrument (for example, "SURFCOM 480A" made by Tokyo Seimitsu or "WYKO N-2500" made by Veeco). As a result, surface roughness of the surface treated by roughening the solder resist layer becomes small to the extent of about 0.1 to 0.6 µm at Ra.

0185In addition, "surface roughness (Ra)" mentioned here means "arithmetic mean roughness (Ra)" prescribed by JIS B0601, but Ra within a range of the above measuring result is mentioned that the smallest Ra is Ra(min) and the largest one is Ra(max) in measured 10 spots.

0186However, surface roughness is measured at random 10 spots in the solder resist layer surface corresponding to the conductor circuit (pad) forming region and the solder resist layer surface corresponding to the conductor circuit non-forming region, but not measured in the boundary vicinity of the conductor circuit forming region and the conductor circuit non-forming region.

(Example 47)

0187Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 38.

(Roughening condition)

0188<tables id="tabl0015" num="0015"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0189Surface roughness of the roughened surface of the solder resist layer becomes small to the extent of about 0.2 to 0.5 µm (Ra(min) to Ra(max)) at Ra.

(Example 48)

0190Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 39.

(Roughening condition)

0191<tables id="tabl0016" num="0016"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0192Surface roughness of the roughened solder resist layer surface becomes small to the extent of about 0.2 to 0.5 µm at Ra.

(Example 49)

0193Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 40.

(Roughening condition)

0194<tables id="tabl0017" num="0017"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0195Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.2 to 0.7 µm at Ra.

(Example 50)

0196Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 41.

(Roughening condition)

0197<tables id="tabl0018" num="0018"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0198Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.1 to 0.5 µm at Ra.

(Example 51)

0199Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 42.

(Roughening condition)

0200<tables id="tabl0019" num="0019"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0201Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.1 to 0.5 µm at Ra.

(Example 52)

0202Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 43.

(Roughening condition)

0203<tables id="tabl0020" num="0020"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0204Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.2 to 0.5 µm at Ra.

(Example 53)

0205Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 44.

(Roughening condition)

0206<tables id="tabl0021" num="0021"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0207Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.2 to 0.6 µm at Ra.

(Example 54)

0208Except that roughening treatment is further applied to the solder resist layer surface with the following condition after flattening treatment, a printed wiring board is manufactured in the same manner as in Example 45.

(Roughening condition)

0209<tables id="tabl0022" num="0022"><table frame="none"><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="35mm" /><colspec colnum="2" colname="col2" colwidth="52mm" /><tbody><row><entry>Roughening solution:</entry><entry>potassium permanganate solution</entry></row><row><entry>Concentration:</entry><entry>60 to 80 g/l</entry></row><row><entry>Temperature:</entry><entry>60 to 80°C</entry></row><row><entry>Immersion time:</entry><entry>1 to 5 minutes</entry></row></tbody></tgroup></table></tables>

0210Surface roughness of the roughened solder resist layer becomes small to the extent of about 0.1 to 0.5 µm at Ra.

0211As to the IC mounted printed wiring boards manufactured according to Examples 46 to 54, the same heat cycle test as in Examples 1 to 36 is carried out, electric resistance after 1500 cycles and after 2000 cycles is measured, and a rate of change (100 x (measured value - initial value)/initial value (%)) with the initial value is obtained. The case within ±10 is evaluated as "good (O) " and the other cases are evaluated as "no good (x)". This test result is shown in Table 4.

0212In addition, as to the IC mounted printed wiring boards manufactured according to Examples 37 to 45 applied no flattening treatment, the same heat cycle test is carried out, a rate of change of electric resistance is obtained and evaluated. These test results are also shown in Table 4 with the test results of Examples 46 to 54. <tables id="tabl0023" num="0023"><table frame="all"><title>(Table 4)</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="28mm" /><colspec colnum="2" colname="col2" colwidth="30mm" /><colspec colnum="3" colname="col3" colwidth="31mm" /><colspec colnum="4" colname="col4" colwidth="21mm" /><colspec colnum="5" colname="col5" colwidth="21mm" /><thead><row><entry morerows="1" align="center" valign="middle">Examples</entry><entry namest="col2" nameend="col3" align="center" valign="middle">Roughness of Roughened Surface (µm)</entry><entry namest="col4" nameend="col5" align="center" valign="middle">Heat Cycle Test</entry></row><row><entry align="center" valign="middle">Ra (minimum)</entry><entry align="center" valign="middle">Ra (Maximum)</entry><entry align="center" valign="middle">1500 cycles</entry><entry align="center" valign="middle">2000 cycles</entry></row></thead><tbody><row><entry align="center" valign="middle">Example 46 (37)</entry><entry align="center" valign="middle">0.1</entry><entry align="center" valign="middle">0.6</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 47 (38)</entry><entry align="center" valign="middle">0.2</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 48 (39)</entry><entry align="center" valign="middle">0.2</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 49 (40)</entry><entry align="center" valign="middle">0.2</entry><entry align="center" valign="middle">0.7</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 50 (41)</entry><entry align="center" valign="middle">0.1</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 51 (42)</entry><entry align="center" valign="middle">0.1</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">○ (X)</entry></row><row><entry align="center" valign="middle">Example 52 (43)</entry><entry align="center" valign="middle">0.2</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">O (X)</entry></row><row><entry align="center" valign="middle">Example 53 (44)</entry><entry align="center" valign="middle">0.2</entry><entry align="center" valign="middle">0.6</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">O (X)</entry></row><row><entry align="center" valign="middle">Example 54 (45)</entry><entry align="center" valign="middle">0.1</entry><entry align="center" valign="middle">0.5</entry><entry align="center" valign="middle">○ (○)</entry><entry align="center" valign="middle">O (X)</entry></row></tbody></tgroup></table></tables>

0213It is understood from the above test result that when a ratio (H/D) of the solder bump height H and the solder resist opening diameter D is within a range of 0.55 to 1.0, connection reliability is improved. Further, mainly, it is understood that unevenness of the solder resist layer surface due to the presence or absence of the connecting pad positioned beneath the solder resist is flattened, and when roughness of the flattened surface is 0.8 to 3 µm of maximum surface roughness (uneven amount), connection reliability is improved. It is assumed that when the height of a solder bump is comparatively large, a space between the IC chip lower face and the solder resist layer surface becomes wider, so that if there is large unevenness (different level), voids tend to be generated within an under fill resin (sealant), but dispersion of the space between the IC chip lower face and the solder resist layer surface becomes small by flattening treatment so as to increase filling ability of the under fill resin.

0214Further, when fine unevenness formed by roughing treatment is existent on the flattened solder resist layer surface, and roughness of the roughened surface is 0.2 µm to 0.5 µm at arithmetic mean roughness Ra, it is understood that connection reliability is further improved. It is assumed that adhesion between the under fill resin and the solder resist layer surface is easily improved, or flux and flux cleaning solvent are hard to remain within a recess of the surface.

(HAST test)

0215The printed wiring boards manufactured according to Examples 1 to 54 and Comparative Examples 1 to 24 are left in atmosphere of temperature: 85°C and humidity: 85% by applying voltage of 3.3V between adjacent and not shorted solder bumps for 50 hours. Thereafter, insulation resistance between the voltage-applied solder bumps is measured.

0216In addition, when insulation resistance is 10⁷ Ω or more, insulation performance is "good (O) "and when insulation resistance is less than 10⁷ Ω, insulation performance is "no good (x)" for evaluation.

0217As the result, it is confirmed that insulation performance of Examples 1 to 54 and Comparative Examples 1 to 12 is good (O) and that of Comparative Examples 13 to 24 is no good (x).

(Observation of voids in bump)

0218As to the printed wiring boards manufactured according to Examples 1 to 54, voids within solder bumps are observed by using an X-ray television system ("SMX-100" made by Shimazu Corporation) and number of voids is measured. 100 solder bumps are randomly selected, but no void is observed.

0219As to the printed wiring boards manufactured according to Examples 1 to 54, except that number of connection pad is changed from 2000 (connecting pad region: about 150 mm²) to 30000 (connecting pad region: 1200 mm²), an IC mounted printed wiring board is manufactured in the same manner as in Examples 1 to 54, each of these examples is conducted to heat cycle test, HAST test and observation of voids in solder bump in the same manner as in Examples 1 to 54, and the same results as Examples 1 to 54 can be obtained.

0220That is, in high density mounting such as 2000 to 30000 connecting pads (connecting region area: 150 to 1200mm²), shear stress due to thermal expansion coefficient difference between the IC chip and the printed wiring board becomes large, but according to the present invention, it is confirmed that a printed wiring board having easily improved connection reliability and insulation reliability is produced.

Industrial Applicability

0221As explained above, the printed wiring board of the invention easily improves connection reliability and insulation reliability, even narrow pitch structure such as 200 µm or less pitch of solder bump, by making a ratio (H/D) of height H from the solder resist layer surface to opening diameter D of the opening 0.55 to 1.0.