Imaging module, endoscope, and method for manufacturing imaging module

Abstract

The invention provides an imaging module, an endoscope, and a method for manufacturing the imaging module. An imaging module includes: a semiconductor package having a plurality of external electrodes disposed on a rear surface thereof; a wiring board in which a plurality of bonding electrodes are disposed on a first main surface, a second main surface is a bottom surface of a recess surrounded by a plurality of walls, and a first wall among the plurality of walls has a cutout communicating with the first main surface; a plurality of electronic components mounted on the second main surface; a plurality of bonding members that respectively bond each of the plurality of external electrodes and each of the plurality of bonding electrodes; a first resin disposed between the back surface and the first main surface; a second resin disposed in the cutout; and a third resin disposed in the recessed portion, in which the first resin, the second resin, and the third resin are the same resin that is integrated with each other and does not have an interface therebetween.

Description

Technical Field

[0001] The present invention relates to an imaging module having electronic components mounted on a wiring board, an endoscope including the imaging module having electronic components mounted on a wiring board, and a method for manufacturing the imaging module having electronic components mounted on a wiring board. Background Art

[0002] International Publication No. 2022 / 244133 discloses a camera module, which includes an imager, a three-dimensional wiring board having a frame-shaped bank connected to the imager, a plurality of electronic components housed in the bank, and a bottom filling resin arranged in the bank. That is, the three-dimensional wiring board has a frame-shaped bank on the side, and a plurality of electronic components are installed on the bottom surface of the recess formed by the bank. The bank prevents the bottom filling resin from expanding to the surroundings.

[0003] The bank portion is provided with a notch as a concave portion for filling an underfill resin into the bank portion. The underfill resin is distinguished from a sealing resin provided at a joint portion between the imager and the three-dimensional wiring board. Summary of the invention

[0004] The camera module of the embodiment comprises: a semiconductor package having a light-receiving surface and a back surface opposite to the light-receiving surface, and including an imager, and a plurality of external electrodes are arranged on the back surface; a wiring board having a first main surface and a second main surface, a plurality of bonding electrodes are arranged on the first main surface, the second main surface is the bottom surface of a recessed portion surrounded by a plurality of walls, and a first wall among the plurality of walls has a notch connected to the first main surface; a plurality of electronic components mounted on the second main surface; a plurality of bonding components, which respectively bond each of the plurality of external electrodes to each of the plurality of bonding electrodes; a first resin, which is arranged between the back surface and the first main surface; a second resin, which is arranged in the notch; and a third resin, which is arranged in the recessed portion, the first resin, the second resin and the third resin being an integral same resin having no interface between each other.

[0005] An endoscope of an embodiment has a camera module at the front end of an insertion portion, and the camera module includes: a semiconductor package having a light-receiving surface and a back surface on the opposite side of the light-receiving surface, and including an imager, and a plurality of external electrodes are arranged on the back surface; a wiring board having a first main surface and a second main surface, and a plurality of bonding electrodes are arranged on the first main surface, the second main surface is the bottom surface of a recess surrounded by a plurality of walls, and a first wall among the plurality of walls has a notch connected to the first main surface; a plurality of electronic components, which are mounted on the second main surface; a plurality of bonding components, which respectively bond each of the plurality of external electrodes to each of the plurality of bonding electrodes; a first resin, which is arranged between the back surface and the first main surface; a second resin, which is arranged in the notch; and a third resin, which is arranged in the recess, and the first resin, the second resin and the third resin are the same resin that is integrated and has no interface with each other.

[0006] The manufacturing method of the camera module of the embodiment has the following steps: preparing a semiconductor package and a wiring board, wherein the semiconductor package has a light-receiving surface and a back surface opposite to the light-receiving surface, and includes an imager, and has a plurality of external electrodes on the back surface, and the wiring board has a first main surface and a second main surface, a plurality of bonding electrodes are arranged on the first main surface, the second main surface is the bottom surface of a recess surrounded by a plurality of walls, a plurality of electronic components are mounted on the second main surface, and a first wall among the plurality of walls has a notch connected to the first main surface; using each of a plurality of bonding components to bond each of a plurality of external electrodes to each of a plurality of bonding electrodes; and injecting liquid resin from the notch or the recess, and curing the resin that extends between the back surface and the first main surface, the notch, and the recess. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a perspective view of the camera module according to the first embodiment.

[0008] Figure 2 It is a cross-sectional view of the camera module according to the first embodiment.

[0009] Figure 3 It is a top view of the camera module according to the first embodiment.

[0010] Figure 4A It is a plan view of the rear surface of the imager of the camera module according to the first embodiment.

[0011] Figure 4B It is a plan view of a first main surface of a wiring board of the camera module according to the first embodiment.

[0012] Figure 5This is a flowchart of the method for manufacturing the camera module according to the first embodiment.

[0013] Figure 6 It is a plan view for explaining the method of manufacturing the camera module according to the first embodiment.

[0014] Figure 7 It is a plan view of the rear surface of the imager of the camera module according to the first embodiment.

[0015] Figure 8 It is a plan view of a camera module according to a modified example of the first embodiment.

[0016] Fig. 9 It is a plan view of a first main surface of a wiring board of a camera module according to a modification of the first embodiment.

[0017] Fig.10 It is a plan view for explaining a method of manufacturing the camera module according to a modification of the first embodiment.

[0018] Fig.11 It is a plan view of the back surface of an imager of a camera module according to a modification of the first embodiment.

[0019] Fig.12 It is a perspective view of a camera module according to a second embodiment.

[0020] Fig.13 It is a perspective view of a camera module according to a modified example of the second embodiment.

[0021] Fig.14 It is a perspective view of an endoscope according to a third embodiment. DETAILED DESCRIPTION

[0022] <First Embodiment>

[0023] Figure 1 , Figure 2 and Figure 3 The camera module 1 of this embodiment is shown. The camera module 1 includes an imager 10 as a semiconductor package, a wiring board 20 , a resin 30 , a solder 40 as a bonding member, an electronic component 50 , and a cable 60 .

[0024] In addition, in the following description, the drawings based on the embodiments are schematic. The relationship between the thickness and width of each part, the ratio of the thickness of each part, etc. are different from the actual. The drawings also contain parts with different relationship and ratio of each other's size. In addition, the illustration and labeling of some components are omitted. In addition, in the drawings, the direction in which the value of the X-axis of the three-axis orthogonal coordinate system increases is called "front", and the direction in which the value of the X-axis decreases is called "back". The direction in which the value of the Z-axis increases is called "up".

[0025] The imager 10 has a light receiving surface 10SA and a back surface 10SB opposite to the light receiving surface 10SA. A plurality of external electrodes 11 are disposed on the back surface 10SB. The imager 10 has an image sensor such as a CMOS image sensor or a CCD image sensor for capturing an object in the optical axis O direction.

[0026] The semiconductor package may have a cover glass bonded to the light receiving surface 10SA of the imager 10. The semiconductor package may have one or more semiconductor elements for processing imaging signals stacked on the back surface of the imager 10, and external electrodes 11 disposed on the back surface 10SB of the semiconductor elements.

[0027] The wiring board 20 has a first main surface 20SA and a side surface orthogonal to the first main surface 20SA, that is, a second main surface 20SB. A plurality of bonding electrodes 21 are arranged on the first main surface 20SA. The second main surface 20SB is the bottom surface of a recessed portion H20 surrounded by a plurality of walls 22 arranged in a frame shape. The first wall 22A of the four walls 22 arranged in a frame shape has a notch C20 connected to the first main surface 20SA. The notch C20 is provided at the end of the first wall 22A.

[0028] The wiring board 20 is a laminated wiring board in which a plurality of wiring layers 23 and a plurality of insulating layers 24 are laminated. For example, the wiring board 20 is manufactured by laminating green sheets having the wiring layers 23 and the insulating layers 24 and firing them.

[0029] The uppermost first insulating layer 24A among the plurality of insulating layers 24 constitutes the plurality of walls 22. Therefore, the depth DC20 of the notch C20 communicating with the first main surface 20SA is equal to the thickness T24 of the first insulating layer 24A.

[0030] A plurality of electronic components 50 are mounted on the second main surface 20SB. The uppermost first wiring layer 23A of the plurality of wiring layers 23 constitutes the second main surface 20SB. That is, pads (not shown) to which the electronic components 50 are soldered are constituted by the first wiring layer 23A. The electronic components 50 are, for example, capacitors, inductors, and ICs.

[0031] A pad 61 to which a cable 60 is soldered is disposed on the rear side of the wiring board 20 where the wiring layer 23 is exposed. The pad 61 is formed of the wiring layer 23. For example, a double-layer plating film composed of a nickel layer and a gold layer may be disposed on the pad.

[0032] Each of the plurality of external electrodes 11 is bonded to each of the plurality of bonding electrodes 21 by each of the plurality of bonding members. The bonding member is solder 40. Figure 4A and Figure 4B As shown, the arrangement and interval G11 of the plurality of external electrodes 11 correspond to the arrangement and interval G21 of the plurality of bonding electrodes 21 .

[0033] Resin 30 includes first resin 30A, second resin 30B, and third resin 30C. First resin 30A is provided between back surface 10SB of imager 10 and first principal surface 20SA of wiring board 20. Since the joint portion using solder 40 is sealed by first resin 30A, camera module 1 has high reliability.

[0034] The second resin 30B is disposed in the notch C20 of the wiring board 20. The third resin 30C is disposed in the recess H20 of the wiring board 20. Since the joint of the electronic component 50 is sealed by the third resin 30C, the reliability of the camera module 1 is high. In addition, the third resin 30C only needs to cover the joint of the electronic component 50, and does not need to reach the upper surface of the wall 22.

[0035] There is no interface between the first resin 30A and the second resin 30B. There is no interface between the second resin 30B and the third resin 30C. The first resin 30A, the second resin 30B, and the third resin 30C are the same resin 30 as a whole. In other words, the first resin 30A and the third resin 30C are connected through the second resin 30B.

[0036] The resin 30 is, for example, a thermosetting resin such as epoxy resin, acrylic resin, polyimide resin, silicone resin, or polyethylene resin. The thermosetting resin is in a liquid state before being cured.

[0037] As described later, the first resin 30A, the second resin 30B, and the third resin 30C are the same resin provided at the same time, so that no air bubbles are left between them and the joints can be sealed without gaps. Therefore, the camera module 1 has high reliability and is easy to manufacture.

[0038] <Method of Manufacturing Camera Module>

[0039] according to Figure 5 The flowchart illustrates a method for manufacturing a camera module.

[0040] <Step S10> Semiconductor package production, wiring board production

[0041] By a known semiconductor manufacturing method, an imaging chip including a plurality of imaging circuits, each of which has a CMOS light-receiving element, etc., is manufactured. A glass chip is bonded to the imaging chip. By cutting the imaging chip to which the glass chip is bonded, a semiconductor package having a light-receiving surface 10SA and a back surface 10SB and having a plurality of external electrodes 11 on the back surface 10SB, i.e., an imager 10, is manufactured. Solder 40 constituting a solder bump is provided on each of the plurality of external electrodes 11.

[0042] The wiring board 20 is manufactured by stacking a plurality of wiring sheets and firing them. The wiring sheet is an unfired component generally called a green sheet, and has a predetermined surface wiring and through wiring. The wiring board 20 may also be a multilayer wiring board in which a plurality of resin layers and a plurality of wiring layers are stacked. The wiring board 20 may also be a molded circuit device (MID: Molded Interconnect Device).

[0043] <Step S20> Electronic Component Installation

[0044] A plurality of electronic components 50 are mounted on second main surface 20SB of wiring board 20, that is, on the bottom surface of recess H20 surrounded by wall 22. That is, electronic components 50 are solder-bonded to pads (not shown) of first wiring layer 23A.

[0045] <Step S30> Joining the semiconductor package to the wiring board

[0046] The external electrodes 11 of the back surface 10SB of the imager 10 as the semiconductor package and the bonding electrodes 21 of the first main surface 20SA of the wiring board 20 are bonded using solder 40 .

[0047] <Step S40> Resin Arrangement

[0048] like Figure 6 As shown, uncured, liquid resin is injected into the recess H20 from the nozzle 8 of the dispenser. The viscosity (25° C.) of the liquid resin 30 is, for example, 40 Pa·s. The liquid resin 30 injected into the recess H20 spreads through the notch C20 to between the back surface 10SB of the imager 10 and the first main surface 20SA of the wiring board 20, that is, to the joint portion using the solder 40.

[0049] Since the resin 30 injected from one place spreads, the first resin 30A between the back surface 10SB of the imager 10 and the first main surface 20SA of the wiring board 20, the second resin 30B of the notch C20, and the third resin 30C of the recess H20 are made of the same resin 30. Therefore, the first resin 30A, the second resin 30B, and the third resin 30C have no interface with each other, and no bubbles remain.

[0050] In order to make the liquid resin injected into the recess H20 flow efficiently and spread to the joint using the solder 40, the interfacial tension is used. Figure 6 As shown, it is preferred that the distance between the back surface 10SB of the imager 10 and the first main surface 20SA of the wiring board 20, that is, the first gap G1 and the width G22 of the notch C20 are less than 0.5 mm.

[0051] In order to make the resin 30 flow more reliably and spread to the joint part using the solder 40, as shown in FIG. Figure 7As shown, the depth DC20 of the notch C20 (the height H22 of the wall 22) is preferably substantially the same as the distance L21A from the center of the bonding electrode 21A closest to the notch C20 to the upper surface 22ASA of the first wall 22A. For example, the depth DC20 exceeds 90% and is less than 110% of the distance L21A.

[0052] Furthermore, the distances L1 and L2 between the electronic component 50A closest to the position where the front end of the nozzle 8 is arranged and the wall 22, the interval L3 between the electronic components 50, the distance L4 between the electronic components 50 other than the electronic component 50A and the wall 22, the width G22 of the notch C20, the distance L5 between the notch C20 and the bonding electrode 21A closest to the notch C20, and the interval G21 between the bonding electrodes 21 preferably satisfy the following formula 1.

[0053] <Formula 1>

[0054] L1, L2≥L3≥L4≥G22≥L5≥G21

[0055] <Step S50> Resin Curing

[0056] The heat treatment is performed, and the liquid resin 30 becomes the solid resin 30. In the early stage of the heat treatment, when the temperature rises, the viscosity of the liquid resin 30 becomes lower than the viscosity at room temperature, and thus the resin 30 further expands due to the interfacial tension.

[0057] <Step S60> Cable Bonding

[0058] The cable 60 is bonded to the pad 61 of the wiring board 20 .

[0059] As described above, in the manufacturing method of the camera module of the present embodiment, the imager 10 as a semiconductor package is bonded to the wiring board 20 using the solder 40 as a bonding member. Then, the resin 30 is arranged between the back surface 10SB and the first main surface 20SA, in the notch C20 and the recess H20. During the arrangement of the resin 30, the liquid resin 30 is injected from the recess H20. The resin 30 that has spread between the back surface 10SB and the first main surface 20SA, in the notch C20 and the recess H20 is cured.

[0060] According to the manufacturing method of the camera module of the present embodiment, a plurality of bonding portions can be reliably and easily sealed with resin. That is, according to the manufacturing method of the camera module of the present embodiment, a camera module with high reliability can be easily manufactured.

[0061] <Modification of First Embodiment>

[0062] The camera module 1A of the modification of the first embodiment is similar to the camera module 1 of the embodiment and has the same effects as the camera module 1. Therefore, in the following description, the same components as those of the camera module 1 are denoted by the same reference numerals and description thereof is omitted.

[0063] like Figure 8-Figure 11 As shown, in the camera module 1A, the width G22A of the notch C20A of the wall 22 of the wiring board 20A is larger than the width G22 of the notch C20 of the camera module 1 .

[0064] Not only the first wall 22A has the notch C20A, but the second wall 22B perpendicular to the first wall 22A is also provided with a notch.

[0065] like Fig.10 As shown, when manufacturing the camera module 1A, the resin 30 is injected from the notch C20A. That is, the tip of the nozzle 8 is arranged at the notch C20A, and the resin 30 is injected.

[0066] In the camera module 1A, the distance L5 between the notch C20A and the bonding electrode 21A closest to the notch C20A, the interval G21 between the bonding electrodes 21, the distance L6 between the electronic component 50B closest to the notch C20A and the wall 22, and the distance L7 between the electronic component 50 other than the electronic component 50B and the wall 22 preferably satisfy the following formula 2.

[0067] <Formula 2>

[0068] L5≥G21, L6≥L7

[0069] <Second Embodiment>

[0070] The camera module 1B of the second embodiment and the camera module 1C of the modified example of the second embodiment are similar to the camera modules 1 and 1A and have the same effects as the camera modules 1 and 1A. Therefore, in the following description, the same reference numerals are given to the same structures as the camera modules 1 and 1A and the description thereof is omitted.

[0071] exist Fig.12 In the camera module 1B shown, the second main surface 20SB of the wiring board 20B on which the electronic component 50 is mounted is the rear surface on the opposite side to the first main surface 20SA. The notch C20B communicates with the first main surface 20SA.

[0072] Although not shown, the cable 60 is joined to a pad on the outer surface of the wall 22 .

[0073] The camera module 1B is shorter in length in the optical axis direction than the camera module 1 and is compact.

[0074] <Modification of Second Embodiment>

[0075] Fig.13 In the camera module 1C shown, similarly to the camera module 1A, the notch C20C is not only provided in the first wall 22A but also is notched in the second wall 22B.

[0076] <Third Embodiment>

[0077] Fig.14 The endoscope 9 of the illustrated embodiment includes an insertion portion 91 , an operation portion 92 , a universal cable 93 , and a connector 94 .

[0078] The insertion part 91 in the shape of an elongated tube is inserted into the body cavity of a living body. The insertion part 91 is provided with a front end part 91A, a bending part 91B, and a flexible tube 91C in sequence from the front end side, and the whole part is flexible. The front end part 91A is provided with a camera module 1 (1A-1C) inside. The bending part 91B is bent in the up-down, left-right direction according to the rotation operation of the bending knob for performing the bending operation of the operation part 92.

[0079] The flexible tube 91C is a flexible tubular member that can bend freely and passively. A treatment instrument channel, a signal line, an optical fiber bundle, etc. are inserted into the flexible tube 91C. The signal line extends from the camera module 1 (1A-1C) of the front end portion 91A via the operation portion 92 to the universal cable 93. The optical fiber bundle guides light from a light source device as an external device to the front end surface of the front end portion 91A.

[0080] The operation portion 92 is connected to the proximal end portion of the insertion portion 91 and includes a plurality of operation members, etc. The universal cable 93 extends from the operation portion 92. The connector 94 is a connection member for connecting the universal cable 93 to an external device.

[0081] As described above, the reliability of the imaging module 1 is high, and therefore the reliability of the endoscope 9 is high. The endoscope 9 including the imaging modules 1A to 1C naturally has the effects possessed by the imaging modules 1A to 1C.

[0082] The endoscope 9 of the embodiment may be a flexible endoscope whose insertion portion 91 is flexible, or may be a rigid endoscope whose insertion portion 91 is rigid. The endoscope 9 may be used for medical purposes or industrial purposes.

[0083] The present invention is not limited to the above-described embodiments and the like, and various modifications, combinations, and applications are possible without departing from the gist of the invention.

Claims

1. A camera module, wherein: The camera module has: A semiconductor package having a light-receiving surface and a back surface opposite to the light-receiving surface, and including an imager, wherein a plurality of external electrodes are arranged on the back surface; A wiring board having a first main surface and a second main surface, wherein a plurality of bonding electrodes are arranged on the first main surface, and the second main surface is a bottom surface of a recess surrounded by a plurality of walls, wherein a first wall among the plurality of walls has a notch communicating with the first main surface; a plurality of electronic components mounted on the second main surface; a plurality of bonding members that respectively bond each of the plurality of external electrodes to each of the plurality of bonding electrodes; a first resin disposed between the back surface and the first main surface; A second resin disposed in the notch; as well as a third resin disposed in the recessed portion, The first resin, the second resin, and the third resin are integrally formed identical resins having no interface therebetween.

2. The camera module according to claim 1, wherein: The second main surface is a side surface orthogonal to the first main surface.

3. The camera module according to claim 1, wherein: The wiring board is a laminated wiring board in which a plurality of wiring layers and a plurality of insulating layers are laminated, The plurality of walls are formed by a first insulating layer among the plurality of insulating layers, The second main surface is constituted by a first wiring layer among the plurality of wiring layers.

4. The camera module according to claim 3, wherein: The depth of the notch is the same as the thickness of the first insulating layer.

5. The camera module according to claim 1, wherein: The notch is arranged at an end portion of the first wall.

6. The camera module according to claim 1, wherein: A first interval between the back surface and the first main surface and a width of the notch are less than 0.5 mm.

7. The camera module according to claim 1, wherein: The depth of the notch is the same as the distance from the center of a bonding electrode closest to the notch among the plurality of bonding electrodes to the upper surface of the first wall.

8. The camera module according to claim 1, wherein: The second main surface is a rear surface on the opposite side of the first main surface.

9. An endoscope having a camera module at the front end of an insertion portion, wherein: The camera module has: A semiconductor package having a light-receiving surface and a back surface opposite to the light-receiving surface, and including an imager, wherein a plurality of external electrodes are arranged on the back surface; A wiring board having a first main surface and a second main surface, wherein a plurality of bonding electrodes are arranged on the first main surface, and the second main surface is a bottom surface of a recess surrounded by a plurality of walls, wherein a first wall among the plurality of walls has a notch communicating with the first main surface; a plurality of electronic components mounted on the second main surface; a plurality of bonding members that respectively bond each of the plurality of external electrodes to each of the plurality of bonding electrodes; a first resin disposed between the back surface and the first main surface; A second resin disposed in the notch; as well as a third resin disposed in the recessed portion, The first resin, the second resin, and the third resin are integrally formed identical resins having no interface therebetween.

10. A method for manufacturing a camera module, wherein: The manufacturing method comprises the following steps: A semiconductor package and a wiring board are manufactured, wherein the semiconductor package has a light-receiving surface and a back surface opposite to the light-receiving surface, and includes an imager, and the back surface has a plurality of external electrodes, and the wiring board has a first main surface and a second main surface, a plurality of bonding electrodes are arranged on the first main surface, the second main surface is the bottom surface of a recess surrounded by a plurality of walls, a plurality of electronic components are mounted on the second main surface, and a first wall among the plurality of walls has a notch communicating with the first main surface; bonding each of the plurality of external electrodes to each of the plurality of bonding electrodes using each of the plurality of bonding members; as well as A liquid resin is injected from the notch or the concave portion, and the resin spread between the back surface and the first main surface, the notch, and the concave portion is cured.

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