Imaging module, endoscope, and imaging module manufacturing method

Abstract

This imaging module comprises: a wiring board that has a first main surface and a second main surface, has lands and a lead-out wiring disposed on the first main surface, has a through-hole, and has a through-wiring layer disposed on the inner surface of the through-hole, the through-wiring layer being in electrical communication with the lead-out wiring; a resin that is disposed in the through-hole and seals an opening on the first main surface side; a joining member that is joined to the lands; and a camera unit that is joined to the joining member.

Description

Image pickup module, endoscope, and method for manufacturing image pickup module

[0001] The present invention relates to an imaging module having a camera unit disposed therein, an endoscope having an imaging module having a camera unit disposed therein, and a method for manufacturing an imaging module having a camera unit disposed therein.

[0002] In recent years, three-dimensional circuit devices, such as molded interconnect devices (MIDs), have been used to reduce the size and increase the functionality of electronic devices.

[0003] Japanese Patent Application Laid-Open Publication No. 2017-23234 discloses an endoscope camera unit that uses an irregular circuit board, which is a three-dimensional circuit device. The camera unit includes an imaging element, a flat wiring board (planar wiring board) on which electronic components are mounted, and an irregular circuit board (three-dimensional wiring board). Multiple cables are connected to each of multiple side surfaces of the irregular circuit board.

[0004] International Publication No. 2021 / 181530 discloses an imaging module having a camera unit mounted in a cavity of a molded circuit device, wherein an external electrode of the camera unit is connected to a signal cable via a through-hole wiring that penetrates the bottom surface of the cavity and reaches the back surface.

[0005] When soldering the camera unit to the three-dimensional circuit device, if solder flows into the through-hole, not only does this reduce the reliability of the joint, but it can also cause the camera unit to move from its designated position. If the optical axis of the camera unit deviates from its designated position, the desired field of view cannot be obtained, and this can lead to a decrease in the performance of the imaging device.

[0006] JP 2017-23234 A International Publication No. 2021 / 181530

[0007] An embodiment of the present invention aims to provide a high-performance imaging module in which a camera unit is accurately joined, an endoscope having a high-performance imaging module in which a camera unit is accurately joined, and a method for manufacturing an imaging module in which a camera unit is accurately joined.

[0008] An imaging module according to one aspect of the present invention includes: a wiring board having a first main surface and a second main surface opposite the first main surface, on which a plurality of lands and a plurality of lead-out wires extending from each of the plurality of lands are arranged; a wiring board having a plurality of through holes penetrating the first main surface and the second main surface, with a plurality of through wiring layers electrically connected to each of the plurality of lead-out wires arranged on inner surfaces of each of the plurality of through holes; a plurality of resins arranged in each of the plurality of through holes and sealing an opening on the first main surface side; a plurality of bonding members bonded to each of the plurality of lands; and a camera unit bonded to the plurality of bonding members.

[0009] An endoscope according to one aspect of the present invention has an insertion section including a tip end on which an imaging module is disposed, the imaging module having a first main surface and a second main surface opposite the first main surface, a plurality of lands and a plurality of lead-out wires extending from each of the plurality of lands disposed on the first main surface, a wiring board having a plurality of through holes penetrating the first main surface and the second main surface, with a plurality of through wiring layers electrically connected to each of the plurality of lead-out wires disposed on the inner surface of each of the plurality of through holes, a plurality of resins disposed in each of the plurality of through holes and sealing an opening on the first main surface side, a plurality of bonding members bonded to each of the plurality of lands, and a camera unit bonded to the plurality of bonding members.

[0010] A method for manufacturing an imaging module according to one aspect of the present invention includes the steps of: fabricating a wiring board having a first main surface and a second main surface opposite the first main surface, wherein a plurality of lands and a plurality of lead-out wires extending from each of the plurality of lands are arranged on the first main surface; a plurality of through holes penetrating the first main surface and the second main surface, wherein a plurality of through wiring layers electrically connected to each of the plurality of lead-out wires are arranged on the inner surface of each of the plurality of through holes; sealing openings of the plurality of through wiring layers on the first main surface side by disposing a plurality of resins in each of the plurality of through holes; and joining each of a plurality of external electrodes of a camera unit to each of the plurality of lands using a bonding member.

[0011] According to the embodiments of the present invention, it is possible to provide a high-performance imaging module in which a camera unit is accurately joined, an endoscope having a high-performance imaging module in which a camera unit is accurately joined, and a method for manufacturing an imaging module in which a camera unit is accurately joined.

[0012] 16 is a perspective view of an imaging module according to a first embodiment. FIG. 17 is a perspective view of an imaging module according to the first embodiment. FIG. 18 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 19 is a partial enlarged view of FIG. 3. FIG. 19 is a flowchart of a method for manufacturing an imaging module according to the first embodiment. FIG. 19 is a perspective view of a base of a wiring board of an imaging module according to the first embodiment. FIG. 19 is a partial cross-sectional view for explaining a method for manufacturing an imaging module according to the first embodiment. FIG. 19 is a partial cross-sectional view for explaining a method for manufacturing an imaging module according to the first embodiment. FIG. 19 is a partial cross-sectional view for explaining a method for manufacturing an imaging module according to the first embodiment. FIG. 19 is a perspective view for explaining a method for manufacturing an imaging module according to the first embodiment. FIG. 19 is a bottom view of a camera unit of an imaging module according to the first embodiment. FIG. 19 is a bottom view of a cavity in a wiring board of an imaging module according to the first embodiment. FIG. 19 is a bottom view of a cavity in a wiring board of an imaging module according to the first embodiment. FIG. 19 is a perspective view of an endoscope according to a second embodiment. FIG. 19 is a cross-sectional view taken along line XVII-XVII in FIG.

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings based on the embodiments are schematic. The relationship between the thickness and width of each part, the thickness ratio of each part, etc., differ from the actual ones. The drawings also include parts with different dimensional relationships and ratios.

[0014] 1 to 4 show an imaging module 1 of this embodiment. The imaging module 1 has a wiring board 20 and a camera unit 10. As will be described later, the wiring board 20 is a three-dimensional wiring board that is a molded interconnect device (MID).

[0015] Wiring board 20 is a three-dimensional (cubic) molded circuit device in which multiple conductor patterns and the like are arranged on an injection-molded three-dimensional substrate. Unlike conventional flat wiring boards, by using wiring board 20, the shape has a function, and further, conductor patterns can be formed on inclined surfaces, vertical surfaces, curved surfaces, through holes, and the like.

[0016] The wiring board 20 has an assembly member 20A and a protrusion 20B protruding from the assembly member 20A. The protrusion 20B, surrounded by a frame-shaped wall, forms a cavity C20, which is a bottomed hole in which the camera unit 10 is housed. The gap between the camera unit 10 housed in the cavity C20 and an inner wall surface 20SS of the cavity C20 is filled with sealing resin 32. Hereinafter, the bottom surface of the cavity C20 will be referred to as a first main surface 20SA, and the surface opposite the first main surface 20SA will be referred to as a second main surface 20SB.

[0017] 3 and 4, the camera unit 10 includes an imager 11 and an optical element 12. The optical element 12 includes a plurality of lenses, etc. The imager 11 is an imaging element such as a CCD or CMOS that converts the subject image collected by the optical element 12 into an electrical signal.

[0018] The camera unit 10 (imager 11) has a plurality of external electrodes 13 on its bottom surface 10SB, which transmit and receive electrical signals. Each of the external electrodes 13 has a solder bump 14X (see FIG. 12 ) disposed thereon, forming a ball grid array. The camera unit 10 is joined to the wiring board 20 by solder 14, which is a joining material formed by melting the solder bumps 14X.

[0019] The wiring board 20 has a plurality of through holes H20 penetrating the first main surface 20SA and the second main surface 20SB. A through wiring layer 23 is disposed on the inner surface of the through holes H20. As will be described later, a resin 30 is disposed in the through holes H20. A wiring pattern 24 extending from the through wiring layer 23 and a pad 25 provided at an end of the wiring pattern 24 are disposed on the second main surface 20SB.

[0020] A plurality of solder resist patterns 31 are disposed on the wiring patterns 24 on the second main surface 20SB. Electronic components, for example, chip capacitors 40, are surface-mounted on the two wiring patterns 24 between the two solder resist patterns 31. The solder resist patterns 31 are disposed in order to mount electronic components on the two parallel-arranged wiring patterns 24. Although not shown, signal cables are joined to the pads 25.

[0021] The first main surface 20SA is provided with lands 21 and lead-out wiring 22 extending from the lands 21. The end of the lead-out wiring 22 is connected to the through wiring layer 23.

[0022] As will be described later, the lands 21, the lead wiring 22, the through wiring layer 23, the wiring pattern 24, and the pads 25 are conductive layers that are deposited simultaneously, and the boundaries between them are not clear.

[0023] The external electrodes 13 of the camera unit 10 are joined to the lands 21 of the wiring board 20 by the solder 14 formed by melting the solder bumps 14X. The melted solder 14 spreads from the lands 21 to the lead wires 22 during joining.

[0024] The inner diameter of the through hole H20 is greater than twice the thickness of the through wiring layer 23. The through hole H20 is not blocked by the through wiring layer 23, and has an opening on the first main surface 20SA. However, this opening is blocked by the resin 30. Therefore, the molten solder 14 does not flow into the through hole.

[0025] As will be described later, when the camera unit 10 is joined to the wiring board 20, if the solder bumps 14X melt, the unfixed camera unit 10 may move in the direction in which the solder 14 flows out. Furthermore, if the solder 14 flows into the through holes H20, the bond between the external electrodes 13 and the lands 21 may be weakened, or the camera unit 10 may be joined at an angle.

[0026] In imaging module 1, the opening of through-hole H20 on first main surface 20SA is sealed with resin 30, so camera unit 10 is accurately joined to a desired position on wiring board 20. Therefore, imaging module 1 has high performance.

[0027] <Method for Manufacturing an Imaging Module> A method for manufacturing an imaging module will be described below with reference to the flowchart of FIG.

[0028] <Step S10> Molding (molded substrate manufacturing process) MID resin is injected into a mold (not shown) that includes a recess in the shape of wiring board 20, and molded substrate 20X as shown in Fig. 6 is manufactured by injection molding. A precursor such as a non-conductive metal complex that becomes a plating catalyst when irradiated with light is added to the MID resin.

[0029] <Step S20> Laser irradiation (through-hole forming process and active layer forming process) As shown in Figure 7, a high-power laser is irradiated from the second main surface 20SB of the molded substrate 20X to form a through-hole H20 extending from the second main surface 20SB to the first main surface 20SA. The opening of the through-hole H20 in the second main surface 20SB is larger than that in the first main surface 20SA. In other words, the inner dimension of the through-hole H20 increases from the first main surface 20SA to the second main surface 20SB. An activated catalyst layer 29 is formed on the wall surface of the through-hole H20.

[0030] 8, a laser is irradiated in a pattern onto the first main surface 20SA and the second main surface 20SB to provide lands 21, lead wirings 22, wiring patterns 24, and pads 25. By irradiating with the laser, a catalyst layer 29 having catalytic activity for electroless plating is formed.

[0031] It is not easy to irradiate the outer peripheral region of the first main surface 20SA, which is the bottom surface of the cavity C20, with a laser. If the wall surface 20SS of the cavity C20 is irradiated with a laser, a catalyst layer will be formed on the wall surface 20SS, resulting in the formation of a plating film. For this reason, as shown in FIG. 8 , it is preferable that the outer peripheral end of the lead wiring 22 be greater than a predetermined distance L from the inner wall surface 20SS of the cavity C20. The predetermined distance L is, for example, preferably greater than 0.1 mm, and particularly preferably greater than 0.2 mm.

[0032] 9, by performing electroless plating, the molded substrate 20X becomes the wiring board 20 having conductor patterns disposed on the first main surface 20SA, the second main surface 20SB, and the through holes H20. The conductor may be, for example, a copper layer on which a barrier layer made of nickel / gold is disposed.

[0033] The through wiring layer 23 has, for example, an opening diameter of 0.05 mm on the first main surface 20SA and an opening diameter of 0.15 mm on the second main surface 20SB.

[0034] <Step S40> Disposing Resist (Resin) As shown in FIG. 10, a dispenser is used to dispose resin 30 in the through holes H20 from the second main surface 20SB side. The resin 30 is preferably solder resist. Solder resist is a resin that has solder resistance, has a high interfacial tension with the solder 14, and prevents solder from adhering to unnecessary areas. The solder resist uses, for example, a thermosetting epoxy resin as its base material.

[0035] It is preferable that the end face T30 of the resin 30 on the first main surface 20SA side is located between the surface 22SA of the lead-out wiring 22 and the first main surface 20SA. The resin 30 only needs to seal at least the opening of the through hole H20 on the first main surface 20SA side. In other words, the resin 30 does not need to completely fill the through hole H20.

[0036] The thickness of the through wiring layer 23 is thick near the first main surface 20SA where the opening of the through hole H20 is small. Therefore, a gently protruding step is present on the inner surface of the through wiring layer 23 near the first main surface 20SA. This is thought to be because the film formation rate is faster in the region where the cross-sectional area of ​​the through hole H20 is small than in other regions due to a faster diffusion rate of metal ions during plating film formation.

[0037] Because there is a step in the vicinity of the first main surface 20SA, the resin 30 injected into the through hole H20 does not spread onto the surface 22SA of the lead wiring 22.

[0038] 11 , when resin 30 is dispensed on second main surface 20SB, solder resist pattern 31 is also dispensed at the same time using the same dispenser. If the same resin (solder resist) as solder resist pattern 31 is used as resin 30, resin 30 and solder resist pattern 31 can be dispensed in one step, resulting in high productivity.

[0039] <Step S50> Mounting the Camera Unit As shown in Figure 12, the multiple external electrodes 13 arranged on the bottom surface 10SB of the camera unit 10 include a first external electrode 13A located at the optical axis O, and multiple second external electrodes 13B arranged at positions that are four-fold symmetric with each other. In other words, the multiple second external electrodes 13B are arranged at positions that overlap when rotated 90 degrees around the center. Solder bumps 14X are arranged on each of the multiple external electrodes 13.

[0040] 13 , lands 21 are arranged on first main surface 20SA of wiring board 20 and are joined to external electrodes 13 of camera unit 10 with solder 14. Lands 21 include first land 21A connected to first external electrode 13A of camera unit 10 and second land 21B connected to second external electrode 13B.

[0041] Lead wires 22 extend radially from each of the second lands 21B. Ends of the lead wires 22 extend to the through wiring layer 23 disposed in the through wire 30.

[0042] In addition, the multiple second external electrodes 13B, the multiple second lands 21B, and the multiple lead-out wirings 22 may be arranged in N-fold symmetric positions (N is a natural number greater than or equal to 2) with the first external electrode 13A (first land 21A) as the center.

[0043] The camera unit 10 is housed and temporarily fixed in the cavity C20 with each of the external electrodes 13 aligned with each of the lands 21.

[0044] <Step S60> Mounting Electronic Components An electronic component, for example, a chip capacitor 40, is temporarily fixed between two solder resist patterns 31 on the second main surface 20SB of the wiring board 20. The terminals of the chip capacitor 40 have, for example, a solder plating film. Solder paste may be applied to the joining positions of the wiring patterns 24. Note that the spacing W1 between the two parallel wiring patterns 24 as shown in FIG. 11 is approximately the same as the terminal spacing W2 of the two-terminal chip capacitor 40.

[0045] Electronic components may also be mounted in region 20SB1 (see FIG. 11 ) of second main surface 20SB, which is opposite the central region of the bottom surface of protrusion 20B. However, the thickness of region 20SB1 (e.g., 0.5 mm) is thinner than the thickness of other regions. Region 20SB1 is subject to significant deformation due to, for example, thermal expansion / contraction, which could result in damage to electronic components mounted in region 20SB1 or poor bonding. For this reason, it is preferable that electronic components mounted in region 20SB1 be large electronic components with a wide bonding area.

[0046] On the other hand, electronic components may also be mounted in a region 20SB2 (see FIG. 11 ) on the second main surface 20SB, which is on the opposite side of the wall of the protrusion 20B. The thickness of the region 20SB2 is greater than the thickness of the other regions. The region 20SB2 is suitable for mounting small electronic components because it is less susceptible to thermal deformation.

[0047] The thermal deformation of wiring board 20 is large in the long axis direction LD and small in the direction perpendicular to long axis direction LD. For this reason, it is preferable that the electronic component has two terminals arranged in a direction perpendicular to long axis direction LD.

[0048] <Step S70> Reflow For example, using a reflow oven, the imaging module 1 is heated to a temperature at which the solder 14 melts. When the imaging module 1 returns to room temperature, the external electrodes 13 of the camera unit 10 are solder-joined to the lands 21 of the wiring board 20. In addition, the chip capacitor 40 is solder-joined to the wiring pattern 24.

[0049] After the reflow process, sealing resin 32 is injected between the cavity C20 and the camera unit 10 and cured, thereby completing the imaging module 1.

[0050] In the reflow process, when the solder 14 melts, the camera unit 10 may move in the direction in which the solder 14 flows out. Furthermore, if the solder 14 flows into the through-hole H20, the bond between the external electrode 13 and the land 21 may be weakened, or the camera unit 10 may be joined at an angle.

[0051] In the imaging module 1, the plurality of lead-out wires 22 from which the solder 14 flows out have the same width and length. In other words, the areas of the plurality of lead-out wires 22 from which the solder 14 flows out after reflow are the same.

[0052] In the imaging module 1, the opening of the through hole H20 is sealed with resin 30. The solder 14 flows out along a plurality of lead-out wirings 22 arranged in N-fold symmetric positions (N is a natural number greater than or equal to 2). Therefore, the camera unit 10 is automatically and accurately bonded to the desired position in the reflow process due to the self-alignment effect. This manufacturing method makes it possible to manufacture a high-performance imaging module 1.

[0053] 14, a dummy lead-out wiring 22X extends from a first land 21A to one of the second lands 21B. Solder resist patterns 33 (33A, 33B) are disposed on both ends of the dummy lead-out wiring 22X. The solder resist pattern 33 may cover the entire surface of the dummy lead-out wiring 22X. The solder resist pattern 33 prevents the solder 14 from flowing out onto the dummy lead-out wiring 22X.

[0054] In the wiring board 20 shown in Figure 14, the areas where each solder 14 of the multiple lead-out wirings 22 spreads are isotropic around the first land 21A, and the areas where each solder 14 spreads are approximately the same.

[0055] Second Embodiment As shown in Fig. 15 , an endoscope 9 of this embodiment has a distal end portion 9A on which an imaging module 1 is disposed, a freely bendable bending portion 9B connected to the base end of the distal end portion 9A, and an elongated flexible portion 9C connected to the base end of the bending portion 9B. The bending portion 9B is bent by the user operating an operating portion 9D. The distal end portion 9A, bending portion 9B, and flexible portion 9C form an insertion portion that is inserted into the body. A universal cord 9E extending from the operating portion 9D is connected to a processor or the like (not shown). Note that Fig. 15 illustrates the longitudinal axis direction LD of the elongated distal end portion 9A.

[0056] The endoscope 9 of this embodiment is a so-called side-viewing type that captures images in the lateral direction during insertion.

[0057] 16, at the distal end portion 9A, the imaging module 1 is housed in a recess in a hard front frame 91. The hard front frame 91 is provided with an illumination optical system 93 that irradiates illumination light transmitted from a light source device (not shown) via a light guide 93A, and the imaging module 1.

[0058] Furthermore, a treatment tool channel 94A is connected to the tip frame 91, allowing the insertion of a predetermined treatment tool. Since the imaging module 1 and the illumination optical system 93 are disposed in a position where the movement of the treatment tool in a direction different from the endoscope insertion direction (long axis direction LD) can be confirmed, it is necessary to make the imaging module 1 as well as the treatment tool channel 94A compact.

[0059] A so-called treatment tool elevator 94 is disposed in front of the treatment tool channel 94A. The direction of the tip of the treatment tool inserted into the treatment tool channel 94A can be changed by the user operating the elevator 94. An endoscope even smaller than the endoscope 9 can be protruded from the elevator 94.

[0060] 17 , in a side-viewing endoscope 9, the multiple through-holes H20 of the imaging module 1 extend in a direction intersecting with the long axis direction LD of the tip portion 9A. The internal dimensions of the multiple through-holes H20 increase in a direction from the outer surface 9ASS on which the imaging module 1 of the tip portion 9A is disposed toward the inside.

[0061] The endoscope 9 has high performance because it includes the imaging module 1 .

[0062] Although the endoscope 9 is a medical flexible endoscope, an endoscope in another embodiment may be an industrial endoscope or a rigid endoscope having a rigid straight tube instead of the flexible section 9C. The imaging module 1 may also be used in a direct-view endoscope in which the subject is directed toward the tip.

[0063] The three-dimensional circuit device is not limited to an MID, and may be created by machining using a 3D printer or by cutting. The material of the three-dimensional circuit device is not limited to resin, and ceramic or glass epoxy may also be used.

[0064] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0065] DESCRIPTION OF SYMBOLS 1...imaging module 9...endoscope 9A...tip portion 9B...bending portion 9C...flexible portion 9D...operation portion 9E...universal cord 10...camera unit 11...imager 12...optical element 13...external electrode 14...solder 14X...solder bump 20...wiring board 20A...assembly portion 20B...protrusion 20X...molded substrate 21...land 22...drawing wiring 23...through wiring layer 24...wiring pattern 25...pad 29...catalyst layer 30...sealing resin 30...resin 30...through wiring 31...solder resist pattern 32...sealing resin 33...solder resist pattern 40...chip capacitor C20...cavity H20...through hole

Claims

1. a wiring board having a first main surface and a second main surface opposite to the first main surface, a plurality of lands and a plurality of lead-out wirings extending from each of the plurality of lands arranged on the first main surface, a plurality of through holes penetrating the first main surface and the second main surface, and a plurality of through wiring layers electrically connected to each of the plurality of lead-out wirings arranged on inner surfaces of each of the plurality of through holes; a plurality of resins disposed in the plurality of through holes, respectively, and sealing the openings on the first main surface side; a plurality of bonding members bonded to the plurality of lands, respectively; an imaging module comprising: a camera unit joined to the plurality of joining members;

2. 2 . The imaging module according to claim 1 , wherein the end faces of the plurality of resins on the first main surface side are positioned between the surfaces of the plurality of lead wires and the first main surface.

3. a plurality of wiring patterns and a plurality of patterned solder resists for mounting electronic components on the plurality of wiring patterns are disposed on the second main surface; 2. The imaging module according to claim 1, wherein the plurality of resins are the same resin as the plurality of patterned solder resists.

4. the wiring board is a three-dimensional wiring board having a protrusion with a cavity surrounded by a wall, the protrusion having the first main surface as a bottom surface, The imaging module according to claim 1 , wherein the camera unit is housed in the cavity.

5. the wiring board is an MID, 5. The imaging module according to claim 4, wherein the distance between the inner surface of the cavity and the ends of the plurality of lead wires is greater than 0.2 mm.

6. the joining member is solder, the plurality of lands include a first land and a plurality of second lands arranged at N-fold symmetric positions (N is a natural number of 2 or more) around the first land; 2. The imaging module according to claim 1, wherein the areas where the solder of each of the plurality of lead wires spreads are substantially the same in area.

7. 7. The imaging module according to claim 6, further comprising a dummy lead wiring that extends from the first land and is connected to any one of the second lands.

8. An imaging module as described in Claim 7, characterized in that both ends of the dummy pull-out wiring are each covered with a solder resist pattern.

9. Each of the plurality of through holes has an inner dimension that increases from the first main surface to the second main surface, The imaging module according to claim 1 , wherein an inner surface of each of the plurality of through wiring layers has a step.

10. The imaging module described in Claim 1, characterized in that the camera unit has a plurality of stacked optical elements and an imager.

11. An insertion section including a tip section at which an imaging module is disposed, The imaging module includes: a wiring board having a first main surface and a second main surface opposite to the first main surface, a plurality of lands and a plurality of lead-out wirings extending from each of the plurality of lands arranged on the first main surface, a plurality of through holes penetrating the first main surface and the second main surface, and a plurality of through wiring layers electrically connected to each of the plurality of lead-out wirings arranged on inner surfaces of each of the plurality of through holes; a plurality of resins disposed in the plurality of through holes, respectively, and sealing the openings on the first main surface side; a plurality of bonding members bonded to the plurality of lands, respectively; an endoscope comprising: a camera unit joined to the plurality of joining members;

12. An endoscope as described in Claim 11, characterized in that the multiple through holes extend in a direction intersecting the longitudinal axis direction of the tip portion.

13. An endoscope as described in Claim 12, characterized in that the inner dimensions of the multiple through holes increase in the direction from the outer surface on which the imaging module of the tip is arranged toward the inside.

14. An endoscope as described in Claim 11, characterized in that the end faces of each of the plurality of resins on the first main surface side are located between the surfaces of the plurality of pull-out wirings and the first main surface.

15. The joining member is solder, the plurality of lands include a first land and a plurality of second lands arranged at N-fold symmetric positions (N is a natural number of 2 or more) around the first land; 12. The endoscope according to claim 11, wherein the areas where the solder of each of the plurality of lead wires is spread are substantially the same.

16. An endoscope as described in Claim 15, characterized in that it has a dummy pull-out wiring extended from the first land and connected to one of the second lands.

17. An endoscope as described in Claim 16, characterized in that both ends of the dummy pull-out wiring are each covered with a solder resist pattern.

18. A process for producing a wiring board having a first main surface and a second main surface opposite the first main surface, a plurality of lands and a plurality of lead-out wirings extending from each of the plurality of lands arranged on the first main surface, a plurality of through holes penetrating the first main surface and the second main surface, and a plurality of through wiring layers electrically connected to each of the plurality of lead-out wirings arranged on the inner surface of each of the plurality of through holes; a step of sealing openings of the plurality of through holes on the first main surface side by disposing a plurality of resins in the plurality of through holes, respectively; and joining each of a plurality of external electrodes of the camera unit to each of the plurality of lands using a joining material.

19. In the process of manufacturing the wiring board, the plurality of lands, the plurality of lead wires, and the plurality of through wiring layers are arranged, and simultaneously, a plurality of wiring patterns are arranged on the second main surface, with the plurality of through wiring layers being electrically connected to each other; a step of disposing a plurality of patterned solder resists for mounting electronic components on the plurality of wiring patterns; and mounting electronic components on the plurality of wiring patterns.

19. The method for manufacturing an imaging module according to claim 18, wherein the step of disposing the plurality of resins is performed simultaneously with the step of disposing the solder resist, and the plurality of resins are the same resin as the solder resist.

20. The process of fabricating the wiring board comprises: A step of molding a three-dimensional substrate; a step of forming through holes and an active layer by laser irradiation; 19. The method for manufacturing an imaging module according to claim 18, further comprising a plating step of arranging the lands, the lead-out wirings, and the through wiring layers.