Camera module assembly method and camera module

The present invention relates to a camera module assembling method and a camera module, and more particularly to an optical unit mounting technique for concentrating light on a light receiving portion of an image sensor.

Conventionally, various structures have been proposed and used as an attachment structure of an optical unit that concentrates light on a light receiving portion of an image sensor chip. For example, in Cited Document 1, an optical unit that directs light to the light receiving portion of the image sensor is pressed against the reference surface of the package body on which the image sensor is mounted, and a rubber member is interposed between the cover glass and the optical unit. The configuration in which the solid-state image sensor package and the optical unit are assembled is described. Further, Reference 2 describes a configuration in which a light-shielding wall is erected around the light-receiving portion of the package body to prevent light from the joint portion between the package body and the optical unit from flowing toward the light-receiving portion. .. Further, Reference 3 describes a configuration in which the lens holder of the optical unit is mounted on the cover glass to reduce the size of the lens so that the outer shape of the lens holder is set to be equal to or less than the inscribed circle diameter of the protective lens. Has been done. The peripheral edge of the cover glass is provided with a light-shielding cover so as not to affect the light-receiving portion.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-252416</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2001-140497</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 11-341366</text></patcit>

<p> However, each of the above configurations has the following problems. First, in the configuration of Cited Document 1, when the image sensor package on which the solid-state image sensor is mounted is attached to the optical unit holding the image pickup lens, the positioning member (rubber member) of the optical unit and the image sensor package rub against each other. As a result, minute dust such as shavings is generated. If the generated dust moves and adheres to the cover glass covering the solid-state image sensor, an image defect will occur in the captured image. Further, in the configuration of Cited Document 2, when the optical unit is attached to the image sensor package, there is a problem that the light-shielding wall and the inner wall of the optical unit rub against each other and dust is generated. That is, as roughly shown in FIG. 12 (a), when the optical unit 1 is attached to the image sensor package 2, both sides rub against each other to generate dust 3, and this dust 3 is generated in FIG. 12 (b). As shown in the above, there is a problem that the cover glass 5 covering the image sensor chip 4 adheres to the surface.</p><p> Further, in the configuration of Cited Document 3, the optical unit is miniaturized by adhering the rear end surface of the optical unit to the cover glass, but it is actually impossible to hold the optical unit only on the upper surface of the image sensor package. is there. In addition, there is a problem that it is difficult to stably obtain sufficient optical accuracy (lens tilt accuracy).</p><p> The present invention has been made in view of the above circumstances, and when the optical unit is attached to a solid-state image sensor package in which the upper surface of the light receiving element is covered with a cover glass, dust adheres to the cover glass while maintaining optical accuracy. It is an object of the present invention to provide a camera module assembly method and a camera module capable of preventing the above.</p>

<p> The above object according to the present invention is achieved by the following configuration. (1) An optical unit that holds an image sensor is mounted on a solid-state image sensor package in which a translucent member is attached to the upper surface of a package body on which the image sensor chip is mounted and the image sensor chip is sealed in the package body. A method of assembling a camera module connected to the translucent member side of the image sensor package, wherein the optical unit surrounds the light receiving region of the image sensor chip on a part of the bottom surface facing the translucent member. A peripheral groove is formed, a first reference surface portion for positioning the optical unit is formed in a part of the package body, and a second reference surface portion that fits with the first reference surface portion is formed in a part of the optical unit. When the elastic member is inserted and held in the peripheral groove of the light receiving region of the optical unit and the second reference surface portion of the optical unit is brought into contact with the first reference surface portion of the package body, the elasticity is formed. The member is brought into contact with the translucent member, and the elastic member is pushed down into the peripheral groove of the light receiving region as the second reference surface portion is pushed into the first reference surface portion to be fitted, and the fitting is performed. A method for assembling a camera module, which comprises separating the surface of the translucent member surrounded by the elastic member from the first reference surface portion and the second reference surface portion via the elastic member.</p><p> According to this camera module assembly method, when the second reference surface portion is brought into contact with the first reference surface portion, the elastic member is in contact with the translucent member, and the translucent member surrounded by the elastic member. The surface of the light-transmitting member can be isolated from the first reference surface portion and the second reference surface portion where dust can be generated via the elastic member, and dust is prevented from adhering to the surface of the translucent member.</p><p>(2) The method for assembling a camera module according to (1), wherein the light receiving region peripheral groove is an annular groove continuous in the circumferential direction, and the elastic member is formed in a continuous annular shape.</p><p> According to this camera module assembly method, the light receiving region peripheral groove is an annular groove, and by inserting an annular elastic member into this annular groove, it is possible to seamlessly cover the light receiving region of the image sensor chip, resulting in dust. Adhesion prevention effect is enhanced.</p><p>(3) Young's modulus of the elastic member is 10²~10⁴ The camera module assembly method according to (1) or (2), which is characterized by being in the range of MPa.</p><p> According to this camera module, the elastic member has an appropriate cushioning property, so that the adhesion to the surface of the translucent member is improved.</p><p>(4) The camera according to any one of (1) to (3), wherein the elastic member is formed in a bellows shape that can be expanded and contracted with respect to the insertion direction into the light receiving region peripheral groove. How to assemble the module.</p><p> According to this camera module, even if the height of protrusion of the elastic member from the peripheral groove of the light receiving region is increased, it can be accommodated within the groove depth of the peripheral groove of the light receiving region when the optical unit is connected. The elastic member can be brought into contact with the translucent member even before the reference surfaces of the package body start to come into contact with each other to isolate the light receiving region of the element, and the adhesion of dust can be prevented more reliably.</p><p>(5) The method for assembling a camera module according to any one of (1) to (4), wherein the elastic member is made of a molded body made of a resin material.</p><p> According to this camera module, the elastic member can be easily formed as a molded body of a resin material.</p><p>(6) The method for assembling a camera module according to any one of (1) to (4), wherein the elastic member is made of a molded body made of a rubber material.</p><p> According to this camera module, the elastic member can be easily formed as a molded body of a rubber material.</p><p>(7) Any one of (1) to (6), wherein the first reference surface portion is formed on the side surface of the package body, and the second reference surface portion is formed on the inner surface of the optical unit. How to assemble the camera module described in the section.</p><p> According to this camera module, the optical axes of the image sensor chip and the optical unit can be accurately aligned by fitting the first reference surface portion and the second reference surface portion.</p><p>(8) It is characterized in that elastic protrusions in contact with the elastic member are arranged on the surface of the translucent member in which the elastic member comes into contact with the surface of the translucent member (1) to (7). The camera module assembly method described in any one of the above.</p><p> According to this camera module, when the elastic projections come into contact with the elastic member, the airtightness of the image sensor chip receiving area by the elastic member on the translucent member is improved, and the intrusion of dust into the light receiving area is further improved. It is definitely prevented.</p><p>(9) A camera module manufactured by the camera module assembly method according to any one of (1) to (8).</p><p> According to this camera module, by providing an elastic member accommodated in the peripheral groove of the light receiving region, when the second reference surface portion is brought into contact with the first reference surface portion, the elastic member is in contact with the translucent member. Therefore, the surface of the translucent member surrounded by the elastic member can be separated from the first reference surface portion and the second reference surface portion where dust can be generated through the elastic member, and dust can be generated on the surface of the translucent member. Is prevented from adhering.</p>

<p> According to the camera module assembly method and the camera module according to the present invention, when the optical unit is attached to a solid-state image sensor package in which the upper surface of the light receiving element of the image sensor chip is covered with a cover glass, the optical unit is covered while maintaining optical accuracy. It is possible to prevent dust from adhering to the glass.</p>

Hereinafter, the method for assembling the camera module and the preferred embodiment of the camera module according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of the camera module according to the present invention, FIG. 2 is a schematic cross-sectional view of the camera module in an assembled state, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. As shown in FIGS. 1 to 3, in the camera module 100, a cover glass 15 which is a translucent member is attached to the upper surface side of a package body 13 on which the image sensor chip 11 is mounted, and the image sensor chip 11 is packaged. It includes a solid-state image sensor package 17 sealed in the main body 13, an optical unit 23 including an image pickup lens 19 and a lens holder 21 for holding the image pickup lens 19, and an annular elastic member 31 described later.

As shown in FIG. 2, the solid-state image sensor package 17 has an image sensor chip 11 such as a CCD mounted in a recess provided in a package body 13 which is a ceramic burnt body, and the image sensor chip 11 is an element. It is sealed in the recess of the package body 13 by the protective cover glass 15. On the side surface of the package body 13, there is an overhanging portion 25 that serves as a reference surface when assembling with the optical unit 23, and the bottom surface of the optical unit 23 is formed with a step portion so as to abut against the overhanging portion 25. ..

The optical unit 23 has a flange portion 27 for attaching to the package body 13 on the base end side of the lens holder 21. An annular groove (light receiving region peripheral groove) 29 is formed on a part of the bottom surface of the flange portion 27 facing the cover glass 15 so as to surround the light receiving region 11a (see FIG. 3) of the image sensor chip 11. In the present embodiment, the annular groove 29 is formed in an annular shape, but the present invention is not limited to this, and a square groove or an intermittent groove may be used. An annular elastic member 31 which is an annular molded body made of a rubber material, a soft synthetic resin material, or the like is mounted on the annular groove 29. That is, one end side of the annular elastic member 31 in the width direction is inserted into the annular groove 29, and the other end side faces the cover glass 15 (contacts after assembly). The annular elastic member 31 has an appropriate cushioning property with respect to the cover glass 15, and the adhesion with the cover glass 15 is enhanced. For this reason, the Young's modulus of the annular elastic member 31 is 10.²~10⁴Those in the MPa range are preferably used. Further, the annular elastic member 31 is not limited to the annular shape, and may have another shape such as a linear shape, and a plurality of the annular elastic members 31 may be inserted into the annular groove 29.

When the optical unit 23 is pushed along the side surface (first reference surface portion) 33 of the step portion of the package body 13, the side surface 33 of the package body 13 and the base end side inner peripheral surface (second) of the optical unit 23 Reference surface part) 35 fits. Then, the lowermost surface 37 of the bottom of the optical unit 23 comes into contact with the flat surface 39 of the overhanging portion 25 of the package body 13, and the optical unit 23 and the package body 13 are in close contact with each other, such as a leaf spring (not shown). It is fixed with an adhesive, etc.

Next, the assembly process of connecting the optical unit 23 to the solid-state image sensor package 17 with respect to the camera module 100 having the above configuration will be described with reference to FIG. FIG. 4 is explanatory views (a), (b), and (c) showing the relationship between the optical unit and the solid-state image sensor package in the assembly process step by step.

As shown in FIG. 4A, when the optical unit 23 and the solid-state image sensor package 17 are separated from each other, the annular elastic member 31 has an annular groove 29 as shown in an enlarged view of the periphery of the annular elastic member in FIG. To depth L₁Is inserted and held in the annular groove 29. At this time, the protruding height of the annular elastic member 31 from the annular groove 29 is L.₂Is said to be.

Next, as shown in FIG. 4 (b), when the base end side inner peripheral surface 35 of the optical unit 23 begins to abut on the side surface 33 of the package body 13, the lower end portion of the annular elastic member 31 is covered by the cover glass 15. It will be in contact with. In other words, the protruding height L of the annular elastic member 31 from the annular groove 29 before contact between the two.₂Is set to a height at which the lower end portion of the annular elastic member 31 comes into contact with the cover glass 15 when the inner peripheral surface 35 on the base end side and the side surface 33 of the package body 13 start to come into contact with each other. Of course, the inner peripheral surface 35 on the base end side and the side surface 33 of the package body 13 may come into contact with the cover glass 15 before they start to come into contact with each other.

Next, as shown in FIG. 4 (c), when the inner peripheral surface 35 on the base end side and the side surface 33 of the package body 13 are fitted and pushed in, the lowermost surface 37 at the bottom of the optical unit 23 becomes the package body 13. It comes into contact with the flat surface 39 of the overhanging portion 25, and both sides are in close contact with each other at the design position of assembly. By the pushing operation of the optical unit 23 at this time, the annular elastic member 31 is inserted into the annular groove 29, and the annular elastic member 31 always maintains a contact state with the cover glass 15.

By the above operation, after the inner peripheral surface 35 on the base end side of the optical unit 23 and the side surface 33 of the package body 13 start to abut, the annular elastic member 31 continues to contact on the continuous curve on the cover glass 15. It will be. As a result, the surface of the cover glass 15 corresponding to the light receiving region 11a of the image sensor chip 11 is covered with the annular elastic member 31 from the region near the inner peripheral surface 35 on the proximal end side and the side surface 33 of the package body 13 where dust may be generated due to rubbing. Is isolated by. That is, when the optical unit 23 is assembled to the solid-state image sensor package 17, dust does not flow from the portion where dust is generated due to rubbing between the members by shielding by the annular elastic member 31, and the image sensor chip 11 It surely prevents dust from adhering to the cover glass 15 on the light receiving region 11a. Therefore, the image captured by the camera module 100 does not cause image defects due to the adhesion of dust in the assembly process, and a high-quality captured image can be obtained.

In addition, the insertion length L of the inner peripheral surface 35 on the base end side of the optical unit 23 and the side surface 33 of the package body 13_S(See Fig. 5) shows the depth L of the annular groove 29._DTo specify. That is, the depth L of the annular groove 29_DIs the insertion depth L of the annular elastic member 31 into the annular groove 29.₁And the insertion length L_SIt is set longer than the sum of and. As a result, the annular elastic member 31 can be held in the annular groove 29 before the optical unit 23 is assembled, and the annular elastic member 31 can be accommodated in the annular groove 29 after the assembly.

By interposing a spring material in the gap between the bottom surface of the annular groove 29 and the annular elastic member 31, the annular elastic member 31 is pressed against the cover glass 15 when the optical unit 23 is assembled, and an image pickup is performed. The light receiving region 11a of the element chip 11 can be more reliably isolated from the dust source.

As described above, according to the camera module 100 of the present embodiment, when the optical unit 23 is assembled to the solid-state image sensor package 17, the region on the cover glass 15 surrounding the light receiving region 11a of the image sensor chip 11 is annularly elastic. Both are connected while being covered by the member 31. As a result, even if the reference surface serving as the positioning portion, that is, the side surface 33 of the package body 13 and the inner peripheral surface 35 on the base end side of the lens holder 21 rub against each other to generate dust, the generated dust is collected on the cover glass 15. It can be prevented from adhering to the light receiving region 11a. Further, since the reference surfaces are fitted and assembled, the occurrence of deviation of the optical axis can be suppressed, and high optical accuracy can be maintained.

Next, a second embodiment of the camera module and the method of assembling the camera module according to the present invention will be described. In this embodiment, the shape of the above-mentioned annular elastic member is changed. FIG. 6 shows an external perspective view of the bellows-type annular elastic member. In the following description, the same reference numerals will be given to the members / parts common to the above-described first embodiment, thereby simplifying or omitting the description. The bellows-type annular elastic member 41 has a width t and an outer diameter that can be inserted into the annular groove 29, and is formed in a bellows shape that can be expanded and contracted in the axial direction (vertical direction in the drawing).

FIG. 7 shows process diagrams (a) and (b) showing how the optical unit is connected to the solid-state image sensor package using a bellows-type annular elastic member. As shown in FIG. 7A, first, the bellows type annular elastic member 41 is inserted into the annular groove 29 of the lens holder 21, and the base end side inner peripheral surface 35 of the lens holder 21 hits the side surface 33 of the package body 13. When starting to come into contact, the bellows-shaped annular elastic member 41 is brought into contact with the surface of the cover glass 15. Then, as shown in FIG. 7B, the bellows-type annular elastic member 41 is housed in the annular groove 29 in a state where the lowermost surface 37 of the lens holder 21 is in contact with the flat surface 39 of the package body 13. As a result, as in the first embodiment, the cover corresponding to the light receiving region 11a of the image sensor chip 11 from the region near the base end side inner peripheral surface 35 and the side surface 33 of the package body 13 where dust due to rubbing can be generated. The surface of the glass 15 is separated by a bellows-type annular elastic member 41. Therefore, it is possible to prevent dust from adhering to the cover glass 15 on the light receiving region 11a of the image sensor chip 11.

Further, since the bellows-type annular elastic member 41 itself can be expanded and contracted by using the bellows-type annular elastic member 41, even if the protruding height of the bellows-type annular elastic member 41 from the annular groove 29 is increased, When the optical unit 23 is connected, it can be accommodated within the groove depth of the annular groove 29. Therefore, the bellows-type annular elastic member 41 can be brought into contact with the cover glass 15 even before the inner peripheral surface 35 on the base end side of the optical unit 23 and the side surface 33 of the package body 13 start to come into contact with each other to isolate the light receiving region 11a. , The adhesion of dust can be prevented more reliably.

Next, a third embodiment of the camera module and the method of assembling the camera module according to the present invention will be described. In this embodiment, the shape of the above-mentioned annular elastic member is changed. FIG. 8 is a partially enlarged cross-sectional view of an annular groove to which a hollow annular elastic member is attached. FIG. 8A shows a state before contact with the cover glass, and FIG. 8B shows a state after contact with the cover glass. The hollow annular elastic member 43 is composed of an elastic member having a hollow structure in which one end side is fixed to the annular groove 29 and the other end side extends long toward the cover glass 15 of the package body 13. By forming the hollow structure, a large amount of deformation can be obtained, and the thickness can be kept thin even in a crushed state in contact with the cover glass 15.

By using the hollow annular elastic member 43 having this configuration, the configuration is simplified, and when the hollow annular elastic member 43 is brought into contact with the cover glass 15, the adhesiveness with the cover glass 15 due to its own elastic repulsive force. Is improved, and the isolation from the area near the inner peripheral surface 35 on the base end side and the side surface 33 of the package body 13 where dust can be generated becomes more reliable.

Next, a fourth embodiment of the camera module and the method of assembling the camera module according to the present invention will be described. In this embodiment, an elastic member is further fixed on the cover glass. FIG. 9 is a (a) plan view and (b) BB sectional view of the cover glass. The fixed elastic member 45 formed in an annular shape on the surface of the cover glass 15 is made of a rubber material and a resin material, and is joined to the surface of the cover glass 15 via an adhesive or fixed by the member material itself. The forming position of the fixed elastic member 45 on the cover glass 15 is a position where it comes into contact with the annular elastic member 31 (same for 41 and 43) of each of the above-described embodiments.

10A and 10B are views for explaining the effect of the fixed elastic member 45, in which FIG. 10A is a partial cross-sectional view showing the state before the annular elastic member comes into contact with the cover glass, and FIG. 10B shows the state after contacting the cover glass. In the illustrated example, the ring-shaped elastic member 31 (41, 43) is in contact with the fixed elastic member 45 inside, but it may be outside or directly above. By forming the fixed elastic member 45 on the cover glass 15 and bringing it into contact with the annular elastic member 31 (41,43) in this way, the airtightness of the annular elastic member 31 (41,43) is improved and dust is generated. Isolation from the possible base end side inner peripheral surface 35 and the region near the side surface 33 of the package body 13 is further ensured.

Here, a modified example of the annular elastic member 31 (the same applies to 41 and 43) will be described with reference to FIG. FIG. 11 shows cross-sectional views of modified examples (a) and (b) in which the tip shape of the annular elastic member is changed. As shown in FIG. 11A, by forming a notch at the tip of the annular elastic member 31 that obliquely contacts the fixed elastic member 45, the sealing performance of the annular elastic member is further improved. Further, as shown in FIG. 11B, by forming a V-shaped notch groove 49 at the tip of the annular elastic member 31, the close contact portion has a two-stage structure, and the sealing property is further improved.

<figref num="1">It is an exploded perspective view of the camera module which concerns on this invention.</figref><figref num="2">It is schematic cross-sectional view in the assembled state of a camera module.</figref><figref num="3">It is a cross-sectional view of AA of FIG.</figref><figref num="4">Explanatory drawings (a), (b), and (c) show stepwise the relationship between the optical unit and the solid-state image sensor package in the assembly process.</figref><figref num="5">It is an enlarged view around the annular elastic member.</figref><figref num="6">It is an external perspective view of the bellows type annular elastic member.</figref><figref num="7">It is a process diagram (a), (b) which shows the state of connecting an optical unit to a solid-state image sensor package using a bellows type annular elastic member.</figref><figref num="8">It is a partially enlarged cross-sectional view of an annular groove to which a hollow type annular elastic member is attached, in which (a) shows a state before contact with a cover glass and (b) shows a state after contact with a cover glass.</figref><figref num="9">It is (a) plan view and (b) BB sectional view of the cover glass.</figref><figref num="10">It is a figure explaining the effect by the fixed elastic member 45, (a) is a partial cross-sectional view which shows the state before contact with a cover glass, (b) is the state after contact.</figref><figref num="11">It is sectional drawing of the modification (a), (b) which changed the tip shape of an annular elastic member.</figref><figref num="12">Explanatory drawings (a) and (b) show how dust is generated in the process of attaching the conventional optical unit to the image sensor package.</figref>

Code description

11 Image sensor chip 11a Light receiving area 13 Package body 15 Cover glass (translucent member) 17 Solid-state image sensor package 19 Image sensor 21 Lens holder 23 Optical unit 29 Circular groove 31 Circular elastic member 33 Side surface (first reference surface) 35 Base end side inner peripheral surface (second reference surface) 41 Bellows-type annular elastic member 43 Hollow-type annular elastic member 45 Fixed elastic member 100 Camera module