Imaging module, endoscope, and manufacturing method of imaging module

Abstract

To provide an imaging module 1 that is highly reliable and can be manufactured easily.SOLUTION: An imaging module 1 includes: an imager 10 in which an external electrode 11 is disposed on a reverse face 10SB; a wiring board 20 in which a junction electrode 21 is disposed on a first principal surface 20SA, and a second principal surface 20SB is a bottom face of a recess H20, and which has a notch C20 on a first wall 22A of the recess H20; an electronic component 50 loaded on the second principal surface 20SB; solder 40 joining the external electrode 11 and the junction electrode 21; first resin 30A disposed between the reverse face 10SB and the first principal surface 20SA; second resin 30B disposed in the notch C20; and third resin 30C disposed in the recess H20. The first resin 30A, the second resin 30B, and the third resin 30C are the same resin 30 that is integrated with no interface in between.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] International Publication No. 2022 / 244133 discloses an imaging module including an imager, a three-dimensional wiring board having a frame-shaped bank joined to the imager, a plurality of electronic components housed in the bank, and an underfill resin disposed 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 mounted on the concave bottom surface formed by the bank. The bank prevents the underfill resin from spreading to the surroundings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 244133 Summary of the Invention [Problem to be solved by the invention]

[0004] In the imaging module of WO 2022 / 244133, the bank is provided with a notch that is a recess for filling the bank with underfill resin. Note that the underfill resin is distinguished from the sealing resin disposed at the joint between the imager and the three-dimensional wiring board.

[0005] An object of the present invention is to provide an imaging module that is highly reliable and easy to manufacture. [Means for solving the problem]

[0006] The imaging module of the embodiment includes a semiconductor package having a light receiving surface and a back surface opposite the light receiving surface, including an imager, and having a plurality of external electrodes arranged on the back surface; a wiring board having a first main surface and a second main surface, and having a plurality of bonding electrodes arranged on the first main surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, and a first wall of the plurality of walls having a notch communicating with the first main surface; a plurality of electronic components mounted on the second main surface; a plurality of bonding members each bonding each of the plurality of external electrodes and each of the plurality of bonding electrodes; a first resin arranged between the back surface and the first main surface, a second resin arranged in the notch, and a third resin arranged in the recess, and the first resin, the second resin, and the third resin are one and the same resin with no interface between them.

[0007] an endoscope according to an embodiment having an imaging module at a tip of an insertion section, the imaging module having a light receiving surface and a back surface opposite the light receiving surface, and including an imager; a semiconductor package having a plurality of external electrodes arranged on the back surface; a first main surface and a second main surface, the first main surface having a concave bottom surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, a first wall of the plurality of walls having a notch communicating with the first main surface; a wiring board; a plurality of electronic components mounted on the second main surface; a plurality of bonding members respectively bonding each of the plurality of external electrodes and each of the plurality of bonding electrodes; a first resin arranged between the back surface and the first main surface, a second resin arranged in the notch, and a third resin arranged in the concave, the first resin, the second resin, and the third resin being one and the same resin with no interface between them.

[0008] A manufacturing method for an imaging module of an embodiment includes the steps of: preparing a semiconductor package having a light-receiving surface and a back surface opposite the light-receiving surface, including an imager, and having a plurality of external electrodes on the back surface; and a wiring board having a first main surface and a second main surface, with a plurality of bonding electrodes arranged on the first main surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, with a plurality of electronic components mounted on the second main surface, and a first wall of the plurality of walls having a notch communicating with the first main surface; bonding each of the plurality of external electrodes and each of the plurality of bonding electrodes using each of a plurality of bonding members; injecting a liquid resin through the notch or the recess; and curing the resin that has spread between the back surface and the first main surface, into the notch, and into the recess. Effect of the Invention

[0009] According to the embodiment of the present invention, it is possible to provide an imaging module that is highly reliable and easy to manufacture. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an imaging module according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view of the imaging module of the first embodiment. [Diagram 3] FIG. 3 is a top view of the imaging module according to the first embodiment. [Figure 4A] FIG. 4A is a plan view of the rear surface of the imager of the imaging module of the first embodiment. [Figure 4B] FIG. 4B is a plan view of the first main surface of the wiring board of the imaging module of the first embodiment. [Diagram 5] FIG. 5 is a flowchart of a method for manufacturing the image pickup module according to the first embodiment. [Figure 6] FIG. 6 is a top view for explaining the manufacturing method of the imaging module of the first embodiment. [Figure 7] FIG. 7 is a plan view of the rear surface of the imager of the imaging module of the first embodiment. [Figure 8] FIG. 8 is a top view of the imaging module according to the first modification of the first embodiment. [Figure 9] FIG. 9 is a plan view of a first main surface of a wiring board of an imaging module according to a first modification of the first embodiment. [Figure 10] FIG. 10 is a top view for explaining a manufacturing method of an image pickup module according to the first modification of the first embodiment. [Figure 11] FIG. 11 is a plan view of the rear surface of the imager of the imaging module according to the first modification of the first embodiment. [Figure 12] FIG. 12 is a perspective view of the imaging module according to the second embodiment. [Figure 13] FIG. 13 is a perspective view of an imaging module according to a first modified example of the second embodiment. [Figure 14] FIG. 14 is a perspective view of an endoscope according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment 1, 2, and 3 show an imaging module 1 of the present embodiment. The imaging module 1 includes an imager 10 which is a semiconductor package, a wiring board 20, a resin 30, solder 40 which is a joining member, an electronic component 50, and a cable 60.

[0012] In the following description, the drawings based on the embodiment are schematic. The relationship between the thickness and width of each part, the thickness ratio of each part, etc. are different from the actual ones. The drawings also include parts with different dimensional relationships and ratios. Also, illustration of some components and assignment of symbols are omitted. 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 "rear". The direction in which the value of the Z-axis increases is called "up".

[0013] The imager 10 has a light receiving surface 10SA and a back surface 10SB opposite 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, that captures an image of a subject in the optical axis O direction.

[0014] The semiconductor package may have a cover glass adhered 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 may be provided on the back surface 10SB of the semiconductor elements.

[0015] The wiring board 20 has a first main surface 20SA and a second main surface 20SB which is a side surface perpendicular to the first main surface 20SA. 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 recess H20 surrounded by a plurality of walls 22 arranged in a frame shape. Of the four walls 22 arranged in a frame shape, a first wall 22A has a notch C20 which communicates with the first main surface 20SA. The notch C20 is provided at an end of the first wall 22A.

[0016] 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, wiring board 20 is manufactured by laminating and firing green sheets each having wiring layer 23 and insulating layer 24.

[0017] The uppermost first insulating layer 24A of the multiple insulating layers 24 constitutes the multiple walls 22. Therefore, the depth DC20 of the notch C20 communicating with the first main surface 20SA is the same as the thickness T24 of the first insulating layer 24A.

[0018] The electronic components 50 are mounted on the second main surface 20SB. The uppermost first wiring layer 23A of the wiring layers 23 constitutes the second main surface 20SB. That is, the lands (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.

[0019] A land 61 to which a cable 60 is soldered is disposed on the rear side of wiring board 20, on which wiring layer 23 is exposed. Land 61 is formed of wiring layer 23. The land may be provided with a two-layer plating film made of, for example, a nickel layer and a gold layer.

[0020] Each of the plurality of external electrodes 11 and each of the plurality of bonding electrodes 21 are bonded to each other by a respective one of a plurality of bonding members. The bonding members are solder 40. As shown in Fig. 4A and Fig. 4B, the arrangement and spacing G11 of the plurality of external electrodes 11 correspond to the arrangement and spacing G21 of the plurality of bonding electrodes G21.

[0021] Resin 30 includes first resin 30A, second resin 30B, and third resin 30C. First resin 30A is disposed between rear surface 10SB of imager 10 and first main surface 20SA of wiring board 20. Since the joints formed by solder 40 are sealed with first resin 30A, imaging module 1 has high reliability.

[0022] Second resin 30B is disposed in notch C20 of wiring board 20. Third resin 30C is disposed in recess H20 of wiring board 20. Since the joints of electronic components 50 are sealed with third resin 30C, imaging module 1 has high reliability. Note that third resin 30C need only cover the joints of electronic components 50, and does not have to reach the upper surface of wall 22.

[0023] 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 an integral, identical resin 30. In other words, the first resin 30A and the third resin 30C are connected by the second resin 30B.

[0024] The resin 30 is, for example, a thermosetting resin such as an epoxy resin, an acrylic resin, a polyimide resin, a silicone resin, a polyvinyl resin, etc. The thermosetting resin is in a liquid state before being hardened.

[0025] As described below, the first resin 30A, the second resin 30B, and the third resin 30C are the same resin that is disposed at the same time, so that no air bubbles remain between them and the joints can be sealed without any gaps, making the imaging module 1 highly reliable and easy to manufacture.

[0026] <Manufacturing method of imaging module> The manufacturing method of the imaging module will be described with reference to the flow chart of FIG.

[0027] <Step S10> Semiconductor package production, wiring board production An imaging wafer including a plurality of imaging circuits, each having a CMOS light receiving element or the like, is fabricated by a known semiconductor manufacturing method. A glass wafer is bonded to the imaging wafer. The imaging wafer with the glass wafer bonded thereto is cut to fabricate an imager 10, which is a semiconductor package having a light receiving surface 10SA and a back surface 10SB, and a plurality of external electrodes 11 on the back surface 10SB. Solder 40 constituting a solder bump is disposed on each of the plurality of external electrodes 11.

[0028] A wiring board 20 is produced by stacking and firing a plurality of wiring sheets. The wiring sheet is an unfired member generally called a green sheet, and has predetermined surface wiring and through wiring. The wiring board 20 may 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 be a molded interconnect device (MID).

[0029] <Step S20> Electronic component mounting A plurality of electronic components 50 are mounted on the bottom surface of recess H20 surrounded by wall 22, which is second main surface 20SB of wiring board 20. That is, electronic components 50 are solder-bonded to lands (not shown) of first wiring layer 23A.

[0030] <Step S30> Bonding the semiconductor package and the wiring board External electrodes 11 on back surface 10SB of imager 10, which is a semiconductor package, and bonding electrodes 21 on first main surface 20SA of wiring board 20 are bonded with solder 40. As shown in FIG.

[0031] <Step S40> Resin placement 6, uncured liquid resin is injected into recess H20 from nozzle 8 of a dispenser. Liquid resin 30 has a viscosity (at 25° C.) of, for example, 40 Pa·s. Liquid resin 30 injected into recess H20 spreads through cutout C20 between back surface 10SB of imager 10 and first main surface 20SA of wiring board 20, i.e., to the joint made by solder 40.

[0032] Since resin 30 injected from one location spreads out, first resin 30A between back surface 10SB of imager 10 and first main surface 20SA of wiring board 20, second resin 30B in cutout C20, and third resin 30C in recess H20 are made of one and the same resin 30. Therefore, there is no interface between first resin 30A, second resin 30B, and third resin 30C, and no air bubbles remain.

[0033] Interfacial tension is used to efficiently flow and spread the liquid resin injected into recess H20 to the joint made of solder 40. For this reason, as shown in Fig. 6, first gap G1, which is the distance between back surface 10SB of imager 10 and first main surface 20SA of wiring board 20, and width G22 of notch C20 are preferably less than 0.5 mm.

[0034] In order to more reliably cause the resin 30 to flow and spread to the joint made of the solder 40, it is preferable that the depth DC20 of the notch C20 (height H22 of the wall 22) is approximately equal to the distance L21A from the center of the joining electrode 21A closest to the notch C20 to the upper surface 22ASA of the first wall 22A, as shown in Fig. 7. For example, the depth DC20 is more than 90% and less than 110% of the distance L21A.

[0035] Furthermore, it is preferable that distances L1, L2 between the wall 22 and the electronic component 50A closest to the position where the tip of the nozzle 8 is positioned, the spacing L3 between the electronic components 50, the distance L4 between the wall 22 and an electronic component 50 other than the electronic component 50A, 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 spacing G21 between the bonding electrodes 21 satisfy the following formula 1.

[0036] <Expression 1> L1, L2≧L3≧L4≧G22≧L5≧G21

[0037] <Step S50> Resin hardening Heat treatment is performed, and the liquid resin 30 becomes a solid resin 30. In the initial stage of heat treatment, as the temperature rises, the viscosity of the liquid resin 30 decreases below that at room temperature, and the resin 30 spreads further due to interfacial tension.

[0038] <Step S60> Cable joining A cable 60 is joined to a land 61 of the wiring board 20 .

[0039] As described above, in the manufacturing method of the imaging module of this embodiment, the imager 10, which is a semiconductor package, and the wiring board 20 are joined by using the solder 40, which is a joining member. Then, the resin 30 is provided between the back surface 10SB and the first main surface 20SA, in the notch C20, and in the recess H20. In providing 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 in the recess H20 is cured.

[0040] According to the method for manufacturing an imaging module of this embodiment, a plurality of joints can be reliably and easily sealed with resin. That is, according to the method for manufacturing an imaging module of this embodiment, a highly reliable imaging module can be easily manufactured.

[0041] <Modification of the first embodiment> The imaging module 1A of the modified example of the first embodiment is similar to the imaging module 1 of the embodiment, and has the same effects as the imaging module 1. For this reason, in the following description, the same components as those of the imaging module 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0042] As shown in FIGS. 8 to 11, in the imaging module 1A, the width G22A of the cutout C20A in the wall 22 of the wiring board 20A is larger than the width G22 of the cutout C20 in the imaging module 1.

[0043] The cutout C20A cuts out not only the first wall 22A but also the second wall 22B perpendicular to the first wall 22A.

[0044] 10, when manufacturing the imaging module 1A, the resin 30 is injected from the notch C20A. That is, the tip of the nozzle 8 is placed in the notch C20A, and the resin 30 is injected.

[0045] In the imaging module 1A, it is preferable that a distance L5 between the cutout C20A and the bonding electrode 21A closest to the cutout C20A, a spacing G21 between the bonding electrodes 21, a distance L6 between the electronic component 50B closest to the cutout C20A and the wall 22, and a distance L7 between an electronic component 50 other than the electronic component 50B and the wall 22 satisfy the following formula 2.

[0046] <Expression 2> L5 ≥ G21, L6 ≥ L7

[0047] <Second embodiment> The imaging module 1B of the second embodiment and the imaging module 1C of the modified example of the second embodiment are similar to the imaging modules 1 and 1A, and have the same effects as the imaging modules 1 and 1A. For this reason, in the following description, the same components as those of the imaging modules 1 and 1A are denoted by the same reference numerals, and description thereof will be omitted.

[0048] 12, second main surface 20SB of wiring board 20B on which electronic components 50 are mounted is the rear surface opposite first main surface 20SA. Cutout C20B communicates with first main surface 20SA.

[0049] Although not shown, the cable 60 is bonded to a land on the exterior surface of the wall 22 .

[0050] The imaging module 1B is smaller than the imaging module 1, with a shorter length in the optical axis direction.

[0051] <Modification of the second embodiment> In the imaging module 1C shown in FIG. 13, like the imaging module 1A, the cutout C20C is formed not only in the first wall 22A but also in the second wall 22B.

[0052] <Third embodiment> An endoscope 9 according to this embodiment shown in FIG. 14 includes an insertion section 91, an operation section 92, a universal cord 93, and a connector 94.

[0053] The insertion section 91, which has a long and thin tube shape, is inserted into a body cavity of a living body. The insertion section 91 has a tip section 91A, a bending section 91B, and a flexible tube 91C, which are arranged in this order from the tip side, and is flexible as a whole. The imaging module 1 (1A-1C) is arranged inside the tip section 91A. The bending section 91B bends in the up, down, left, and right directions in response to a rotation operation of a bending knob of an operation section 92 for performing a bending operation.

[0054] The flexible tube 91C is a tubular member having flexibility that is passively flexible. A treatment tool channel, a signal line, a fiber bundle, and the like are inserted inside the flexible tube 91C. The signal line extends from the imaging module 1 (1A-1C) of the distal end portion 91A through the operation unit 92 to the universal cord 93. The fiber bundle guides light from a light source device, which is an external device, to the distal end surface of the distal end portion 91A.

[0055] The operation unit 92 is connected to the base end of the insertion unit 91 and has a plurality of operation members, etc. The universal cord 93 extends from the operation unit 92. The connector 94 is a connection member for connecting the universal cord 93 to an external device.

[0056] As already described, the imaging module 1 is highly reliable, and therefore the endoscope 9 is highly reliable. It goes without saying that the endoscope 9 including the imaging modules 1A-1C has the same effects as the imaging modules 1A-1C.

[0057] The endoscope 9 of the embodiment may be a flexible scope having a flexible insertion portion 91, or a rigid scope having a rigid insertion portion 91. The endoscope 9 may be used for medical or industrial purposes.

[0058] The present invention is not limited to the above-described embodiments, and various modifications, combinations, and applications are possible without departing from the spirit and scope of the invention. [Explanation of symbols]

[0059] 1, 1A-1C... Imaging module 8…Nozzle 9. Endoscope 10. Imager 20... Wiring board 21… Junction electrode 22... Wall 22A... First wall 22B... The second wall 23... Wiring layer 23A… First wiring layer 24… Insulation layer 24A… First insulating layer 30…Resin 30A… First resin 30B: Second resin 30C: Third resin 40… Solder 50, 50A, 50B... Electronic components 60…Cable 61… Land 91… Insertion section 91A...Tip

Claims

1. a semiconductor package having a light receiving surface and a back surface opposite to the light receiving surface, the semiconductor package including an imager, and a plurality of external electrodes disposed on the back surface; a wiring board having a first main surface and a second main surface, a plurality of bonding electrodes being disposed on the first main surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, a first wall of the plurality of walls having a notch communicating with the first main surface; A plurality of electronic components mounted on the second main surface; a plurality of bonding members each bonding the plurality of external electrodes to 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; a third resin disposed in the recess; 11. An imaging module, comprising: the first resin, the second resin, and the third resin, each of which is an identical resin with no interface therebetween.

2. The imaging module according to claim 1 , wherein the second main surface is a side surface perpendicular to the first main surface.

3. the wiring board is a laminated wiring board in which a plurality of wiring layers and a plurality of insulating layers are laminated, the walls are formed by a first insulating layer of the plurality of insulating layers; 2. The imaging module according to claim 1, wherein the second main surface is formed by a first wiring layer of the plurality of wiring layers.

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

5. The imaging module according to claim 1 , wherein the cutout is provided at an end of the first wall.

6. 2 . The imaging module according to claim 1 , wherein the first gap between the rear surface and the first main surface and the width of the notch are less than 0.5 mm.

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

8. The imaging module according to claim 1 , wherein the second main surface is a rear surface opposite to the first main surface.

9. The insertion part has an imaging module at its tip, The imaging module includes: a semiconductor package having a light receiving surface and a back surface opposite to the light receiving surface, the semiconductor package including an imager, and a plurality of external electrodes disposed on the back surface; a wiring board having a first main surface and a second main surface, a plurality of bonding electrodes being disposed on the first main surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, a first wall of the plurality of walls having a notch communicating with the first main surface; A plurality of electronic components mounted on the second main surface; a plurality of bonding members each bonding the plurality of external electrodes to 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; a third resin disposed in the recess; An endoscope, characterized in that the first resin, the second resin, and the third resin are an identical resin with no interface therebetween.

10. a semiconductor package having a light receiving surface and a back surface opposite to the light receiving surface, the semiconductor package including an imager, and a plurality of external electrodes on the back surface; a wiring board having a first main surface and a second main surface, a plurality of bonding electrodes being disposed on the first main surface, the second main surface being a concave bottom surface surrounded by a plurality of walls, a plurality of electronic components being mounted on the second main surface, and a first wall among the plurality of walls having a notch communicating with the first main surface; The plurality of external electrodes are joined to the plurality of joining electrodes by using a plurality of joining members, respectively; A method for manufacturing an imaging module, comprising: injecting liquid resin through the cutout or the recess; and hardening the resin that has spread between the back surface and the first main surface, into the cutout, and into the recess.

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