Method of assembling closed-type electronic component and enclosed saw filter

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an active portion that functions as an electronic component, such as a comb tooth electrode portion in a SAW filter, and a method for assembling a sealed electronic component that needs to protect the active portion from dust, moisture, and the like. And the sealed SAW filter assembled by the assembly method.

【0002】

[Conventional technology]

In recent years, the production volume of electronic components has continued to increase, and a wide variety of package forms have been proposed accordingly. For example, there are forms such as CSP (chip sides package), C4 (Controlled Collapse Chip Connection), BGA (Ball Grid Allay), and QFP. In particular, chip size packages that realize small size and light weight are considered to be important. In conventional semiconductor elements such as IC chips, gold bumps, solder bumps, and the like are formed on electrodes, mounted on a mounting substrate, and then fixed with a sealing material. As an example of this, to explain with reference to FIG. 16, bump 3 made of gold, for example, is formed on the electrode of the semiconductor element 1 by stud bump bonding or the like. Then, the bump 3 is joined while applying ultrasonic vibration on the substrate electrode 4 on the mounting substrate 2 made of ceramic or resin material. After that, the joint portion between the bump 3 and the substrate electrode 4 and the peripheral portion of the semiconductor element 1 are sealed with a sealing material 5 such as an insulating resin.

【0003】

Further, in electronic components such as SAW (Surface Acoustic Wave) filters, foreign matter must not intervene in the active surface, so the SAW filter 6 is mounted on the cavity type ceramic substrate 7 as shown in FIG. The SAW filter 6 is fixed by the die bonding material 11 and is conducted by wire bonding using the gold wire 8 as shown in FIG. After that, in both cases, the metal plate 9 was covered with a glass material or solder 10 on the upper part of the ceramic substrate 7 to seal the cavity.

【0004】

[Problems to be Solved by the Invention]

However, in the above-mentioned conventional method, when the bump 3 is joined while applying ultrasonic vibration on the substrate electrode 4, the stress is concentrated in the vicinity of the joint between the bump 3 and the electrode of the semiconductor element 1, and the semiconductor element 1 It is conceivable that the circuit forming surface of the above may be damaged. Further, when the package is stored in the cavity, the shape of the package is special, and a step of closing the lid is required. Therefore, in either case, there is a problem that it is difficult to stabilize the product quality and reduce the mounting cost. The present invention has been made to solve such a problem, and is a method of assembling a sealed electronic component capable of stabilizing product quality and reducing a mounting cost, and a sealed product assembled by the assembling method. The purpose is to provide a SAW filter.

【0005】

[Means for solving problems]

In order to achieve the above object, the present invention is configured as follows. That is, the sealed electronic component assembling method according to the first aspect of the present invention is an electronic component having an active portion and a plate-shaped active portion sealing member having substantially the same size as the electronic component, and the active portion has substantially the same size. By arranging the active portion sealing member having a concave portion having a corresponding size and forming a non-contact concave portion with the active portion so as to face each other, and combining the electronic component and the active portion sealing member, the above The active portion is sealed with the recess.

【0006】

The forming surface of the electronic component forming the active portion has an electrode connected to the active portion, and the active portion sealing member is provided corresponding to the electrode and penetrates the active portion sealing member. When the hole for the external electrode is provided, after the electronic component and the member for sealing the active portion are combined, a conductive material is provided in the hole for the external electrode, and the conductive material is used for electricity between the electrode and the mounting substrate. You may make a target connection.

【0007】

The recess of the active portion sealing member may be formed by providing a space forming material on the processed surface of the active portion sealing member facing the active portion so as to correspond to the periphery of the active portion.

【0008】

The recess of the active portion sealing member may be formed by digging the processed surface of the active portion sealing member facing the active portion corresponding to the active portion.

【0009】

The conductive material can be solder or silver paste.

【0010】

The electrical connection between the electrode and the mounting substrate made of the conductive material can be performed by flip-chip mounting or wire bonding.

【0011】

Further, in the closed electronic component assembly method according to the second aspect of the present invention, in the first aspect, the electronic component is a SAW filter, the active portion is a comb tooth electrode portion constituting the SAW filter, and the active portion. The sealing member is a Si substrate, the SAW filter is formed in a grid pattern on a semiconductor wafer, the Si substrate is a wafer shape, and the recesses are formed in a grid pattern. It is formed in a grid pattern corresponding to the tooth electrode portion, and after the wafer-shaped SAW filter and the wafer-shaped Si substrate are united, the combined wafer may be diced to be individualized. ..

【0012】

Further, the sealed SAW filter according to the third aspect of the present invention is characterized in that it is assembled by the sealed electronic component assembly method according to the second aspect.

【0013】

BEST MODE FOR CARRYING OUT THE INVENTION

The sealed electronic component assembly method according to the embodiment of the present invention and the sealed SAW filter assembled by the method will be described below with reference to the drawings. In each figure, the same components are designated by the same reference numerals. Further, a SAW filter is taken as an example of a sealed electronic component, but the present invention is not limited to this. That is, a sealed electronic component that needs to protect the active portion from dust, moisture, etc. without directly contacting the active portion, which is a portion that fulfills the function of the electronic component, is applicable. Further, a Si substrate is taken as an example of an active portion sealing member that is combined with the electronic component to seal the active portion, but the present invention is not limited to this, and a plate-like body such as a glass plate is used. It may be.

【0014】

In the present embodiment, the SAW filter is formed in a grid pattern on the semiconductor wafer 121 as shown in FIG. 3, so that an IC (integrated circuit) is formed in a grid pattern on a Si wafer, for example, by a semiconductor chip manufacturing process. ing. One of them is shown in FIGS. 9 and 14. Here, FIG. 9 is a side view thereof, and FIG. 14 is a plan view. As shown in FIG. 14, each SAW filter 122 formed on the semiconductor wafer 121 has a forming surface 125 on the semiconductor substrate 121a when each SAW filter 122 on the semiconductor wafer 121 is cut into individual SAW filters 122. A comb tooth electrode portion 123 corresponding to an example of the active portion is formed in the central portion of the above, and electrodes electrically connected to the comb tooth electrode portion 123 are formed at the four corners of the semiconductor substrate 121a on the forming surface 125. Has been done. Further, bumps 124 are formed on each electrode. Taking a sealed SAW filter 133 formed by sealing the SAW filter 122 as an example, the method for assembling the sealed electronic component will be described.

【0015】

In this embodiment, as described above, the Si substrate 111 is used as an example of the active portion sealing member. In the present embodiment, the Si substrate 111 has a wafer shape as shown in FIG. 3, and corresponds to each SAW filter 122 formed in a grid pattern on the semiconductor wafer 121 as described above. On the substrate 111, the compartments 113 shown in FIG. 13 corresponding to the respective active portion sealing members 111a are virtually arranged in a grid pattern. The size of one compartment 113 is equal to or approximately equal to the size of one SAW filter 122. In such a Si substrate 111, the Si substrate 111 is moved in the thickness direction of each of the compartments 113 arranged in a grid pattern by dry etching, wet etching, or sandblasting as shown in FIGS. 6 and 13. Holes 112 for external electrodes to penetrate are formed at the four corners of the compartment 113. The placement positions of the four external electrode holes 112 formed in one compartment 113 coincide with the placement positions of the four bumps 124 formed in one SAW filter 122.

【0016】

In the next step, a recess for sealing the comb tooth electrode portion 123 is formed in each of the above sections 113. Specifically, as shown in FIGS. 13 and 7, the comb-tooth electrode-corresponding region 116 corresponding to the comb-tooth electrode portion 123 of each SAW filter 122 is masked with a resist on the machined surface 114 of the Si substrate 111. Form a pattern. That is, a mask is formed in the comb tooth electrode corresponding region 116 in each compartment 113. After that, it corresponds to an example in which a portion other than the comb tooth electrode corresponding region 116 in each compartment 113, that is, a forming region 117 having a mesh pattern in FIG. 13 functions as a space forming material by a sputtering or vapor deposition method. The Si oxide film 115 is formed with a thickness of 0.5 to 1 μm. Since the Si oxide film 115 is not formed in the comb tooth electrode compatible region 116 by the mask, the Si oxide film 115 forms a recess 118 corresponding to the comb tooth electrode compatible region 116 in the active portion sealing member 111a. Tooth.

【0017】

In the next step, as shown in FIG. 8, the adhesive 119 is supplied onto the Si oxide film 115 on the Si substrate 111 by a printing method. Next, the adhesive 119 adheres to the forming surface 125 of the semiconductor substrate 121a, and each SAW filter 122 and each active portion sealing member 111a face each other so as to correspond to the comb tooth electrode portion 123 and the comb tooth electrode. The Si substrate 111 and the semiconductor wafer 121 are arranged so as to face the region 116, and both are overlapped and united as shown in FIG. Further, by arranging the Si substrate 111 and the semiconductor wafer 121 as described above, the bumps 124 of each SAW filter 122 are formed on the outer compartments 113 of the Si substrate 111 facing each SAW filter 122. It is inserted into the electrode hole 112. As a result of the above coalescence, as shown in FIG. 10, each comb tooth electrode portion 123 becomes non-contact with the processed surface 114 of the active portion sealing member 111a due to the Si oxide film 115 and the adhesive 119, and each comb tooth electrode portion becomes non-contact. The circumference of the portion 123 is surrounded by the Si oxide film 115 and the adhesive 119. Therefore, each comb tooth electrode portion 123 is sealed in the recess 118 by the Si oxide film 115 and the adhesive 119. Then, the combined wafer 131 is heated to cure the adhesive 119, and the Si substrate 111 and the semiconductor wafer 121 are adhered to each other. When, for example, a glass plate is used for the active portion sealing member 111a, the adhesive 119 can be cured by light.

【0018】

In the next step, as shown in FIG. 1, the printing method, the dispensing method, and the printing method and the dispensing method are performed from the non-machined surface 114a side facing the machined surface 114 of the Si substrate 111 into each external electrode hole 112 into which each bump 124 is inserted. Alternatively, a transfer method is used to supply a conductive material 132 such as solder or silver paste to electrically connect the bump 124. At this time, the conductive material 132 is supplied in an amount protruding from the non-processed surface 114a. Then, the conductive material 132 is cured by thermosetting or reflow. By the curing, an electrode is formed from the bump 124 formed on the SAW filter 122 through the hole 112 for an external electrode on the non-processed surface 114a side of the Si substrate 111 with the conductive material 132.

【0019】

In the next step, the combined wafer 131 in which the electrodes of the conductive material 132 are formed on the non-processed surface 114a side is diced and divided into individual sealed SAW filters 133 as shown in FIG. Each of the divided sealed SAW filters 133 is mounted on the solder-printed electrode 142 of the mounting substrate 141, as shown in FIG. Then, the solder is melted by reflow to connect the sealed SAW filter 133 and the mounting board 141.

【0020】

As described above, according to the sealed electronic component assembly method of the present embodiment and the sealed SAW filter 133 assembled by the method, the comb tooth electrode portion of the SAW filter 122 which is an example of the active portion of the electronic component. A recess 118 for protecting 123 is provided in the active portion sealing member 111a so that the active portion sealing member 111a and the SAW filter 122 are joined. Therefore, when assembling the sealed SAW filter 133, the comb tooth electrode portion 123 is housed in the recess 118, so that, for example, other members are not in direct contact with each other to protect the comb tooth electrode portion 123. , The comb tooth electrode portion 123 is not damaged. Further, the storage form in the recess can improve the airtightness of the comb tooth electrode portion 123, and as a result, the moisture resistance can be improved. Further, as the active portion sealing member 111a for sealing the comb tooth electrode portion 123, a flat plate such as a Si substrate 111 can be used, and the active portion sealing member 111a and the SAW filter 122 are joined as described above. By doing so, the comb tooth electrode portion 123 can be sealed. Therefore, a specially shaped package such as the conventional cavity type ceramic substrate 7 is not required, and the step of covering the ceramic substrate 7 is also unnecessary. From these points, it is possible to stabilize the product quality and reduce the mounting cost as compared with the conventional one.

【0021】

Further, since the active portion sealing member 111a is a flat plate, a through hole can be easily formed. That is, it is possible to provide an external electrode hole 112 for electrically connecting to the bump 124 provided on the electrode of the SAW filter 122 and for forming an electrode on the outside of the sealed SAW filter 133. Therefore, by providing the conductive material 132 in the hole 112 for the external electrode, the external electrode of the sealed SAW filter 133 can be easily formed from the conductive material 132, and the external electrode is mounted. The sealed SAW filter 133 can be easily mounted on the substrate 141.

【0022】

Further, the active portion sealing member 111a is a flat plate, and the formation of the Si oxide film 115 on the formation region 117 of the active portion sealing member 111a is the same as the known manufacturing process of a semiconductor chip on a Si wafer, for example. Steps can be used. Therefore, the recess 118 in the active portion sealing member 111a can be easily formed.

【0023】

Further, as described with reference to FIGS. 3 to 5, in the present embodiment, both the active portion sealing member 111a and the SAW filter 122 are handled in a wafer state to produce the combined wafer 131, for example. A process similar to the known manufacturing process of a semiconductor chip on a Si wafer can be used. Therefore, since a package having a special shape and a step of covering the package are not required, the sealed SAW filter 133 can be easily manufactured.

【0024】

In the above-described embodiment, the formation of the recess 118 in the active portion sealing member 111a is performed by forming the Si oxide film 115 in the formation region 117, but the formation method is not limited to this. For example, as shown in FIG. 11, the recess 118 may be formed by digging the comb tooth electrode corresponding region 116 on the processed surface 114 of the active portion sealing member 111a by dry etching, wet etching, or sandblasting. .. Then, as shown in FIG. 12, the same effect as that of the above-described embodiment can be obtained by the method of joining with the SAW filter 122.

【0025】

Further, regarding the mounting of the sealed SAW filter 133 on the mounting substrate 141, the flip chip mounting method is taken as an example in the above-described embodiment, but the mounting is not limited to this. That is, for example, as shown in FIG. 15, the sealed SAW filter 133 is fixed on the mounting substrate 141 using the adhesive 143, and the conductive material 132 of the sealed SAW filter 133 and the electrodes of the mounting substrate 141. The 142 may be wire-bonded with the gold wire 144.

【0026】

[Effect of the invention]

As described in detail above, according to the sealed electronic component assembly method of the first and second aspects of the present invention and the sealed SAW filter of the third aspect, the recess that protects the active portion of the electronic component is sealed in the active portion. It was provided on the member for sealing, and the member for sealing the active portion and the electronic component were joined. Therefore, when assembling the sealed electronic component, the active portion is housed in the recess, so that the active portion is damaged because, for example, other members are not in direct contact with each other to protect the active portion. Will not be given. Further, the airtightness of the active portion can be improved, and as a result, the moisture resistance can be improved. Further, as the active part sealing member for sealing the active part, a flat plate such as a Si substrate can be used, and as described above, the active part sealing member and the electronic component are joined to seal the active part. Can be done. Therefore, a package having a special shape unlike the conventional cavity type is not required, and the step of covering the package is also unnecessary. From the above points, it is possible to stabilize the product quality and reduce the mounting cost as compared with the conventional case.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing of the sealed SAW filter assembled by the closed type electronic component assembly method of this embodiment.

[Figure 2]

It is a figure which shows the state which the sealed SAW filter shown in FIG. 1 is mounted on the mounting board.

[Fig. 3]

It is a perspective view which shows the Si substrate and the semiconductor wafer manufactured by the closed type electronic component assembly method of this embodiment.

[Fig. 4]

It is a perspective view of the combined wafer which combined both wafers shown in FIG.

[Fig. 5]

It is a figure which shows the state which diced the united wafer shown in FIG. 4, and divided into individual sealed SAW filters.

[Fig. 6]

It is sectional drawing of the active part sealing member used in the closed type electronic component assembly method of this embodiment.

[Fig. 7]

It is a figure which shows the state which formed the Si oxide film on the active part sealing member shown in FIG.

[Fig. 8]

It is a figure which shows the state which provided the adhesive on the Si oxide film of the active part sealing member shown in FIG.

[Fig. 9]

It is a figure of the SAW filter used in the closed type electronic component assembly method of this embodiment.

[Fig. 10]

It is a figure which shows the state in which the active part sealing member shown in FIG. 7 and the SAW filter shown in FIG. 9 are joined.

[Fig. 11]

It is a figure for demonstrating the modification of the concave part formation in the active part sealing member shown in FIG.

[Fig. 12]

It is a figure which shows the state which joined the active part sealing member shown in FIG. 11 and the SAW filter shown in FIG.

[Fig. 13]

It is a figure for demonstrating the modification of the mounting method of the sealed SAW filter shown in FIG. 1 on a mounting board.

[Fig. 14]

It is a plan view of the SAW filter shown in FIG.

[Fig. 15]

It is a figure which shows the state in the modified example of the state shown in FIG. 2 when the sealed SAW filter shown in FIG. 1 is mounted on the mounting board.

[Fig. 16]

It is a figure for demonstrating the sealing method of the electronic component mounted by the conventional flip chip method.

[Fig. 17]

It is a figure for demonstrating another example of the sealing method of the electronic component mounted by the conventional flip chip method.

[Fig. 18]

It is a figure for demonstrating the sealing method of the electronic component mounted by the conventional wire bond method.

[Explanation of symbols]

111a ... Active part sealing member, 112 ... External electrode hole, 114 ... Processed surface, 115 ... Si oxide film, 118 ... Recession, 121 ... Semiconductor wafer, 122 .. .SAW filter, 123 ... comb electrode part, 124 ... bump, 125 ... forming surface, 131 ... coalesced wafer, 132 ... conductive material, 141 ... mounting substrate.