Imaging unit, endoscope, and method for manufacturing imaging unit

Abstract

To provide a highly reliable imaging unit. [Solution] The imaging unit 1 comprises a semiconductor package 10, a planar circuit board 20, an irregular circuit board 30 having a recess T30, a plurality of electronic components 40, and a resin 50 filling the recess T30, wherein the irregular circuit board 30 has a distance W between a first wall surface T30S1 and a second wall surface T30S2 of the recess T30 which becomes smaller toward a bottom surface T30SB, and a first distance L1 between a first electronic component 41 of the plurality of electronic components 40 and the first wall surface T30S1 is greater than a maximum second distance L2-L4 between each of a plurality of electronic components 42-45 other than the first electronic component 41 and an adjacent wall surface of the first wall surface T30S1 or the second wall surface T30S2.

Description

[Technical field]

[0001] The present invention relates to an imaging unit in which a plurality of electronic components are mounted between a planar circuit board and an irregular circuit board, an endoscope having an imaging unit in which a plurality of electronic components are mounted between a planar circuit board and an irregular circuit board, and a method for manufacturing an imaging unit in which a plurality of electronic components are mounted between a planar circuit board and an irregular circuit board. [Background technology]

[0002] Japanese Patent Application Publication No. 2017-23234 discloses an imaging unit for an endoscope using an irregular circuit board that is a three-dimensional circuit device. The imaging unit includes a semiconductor package, a planar circuit board that is joined to the semiconductor package and has a plurality of electronic components mounted thereon, and an irregular circuit board that is joined to the planar circuit board and has the plurality of electronic components housed in cutouts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-23234 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is preferable that the multiple electronic components housed in the notches are sealed with resin to improve reliability, but it is not easy to fill the spaces between multiple small electronic components with resin. [Means for solving the problem]

[0005] An imaging unit according to an embodiment of the present invention includes a semiconductor package having an imaging element, the semiconductor package having a first surface and a second surface opposite to the first surface, and a plurality of first electrodes arranged on the second surface; a planar circuit board having a third surface and a fourth surface opposite to the third surface, the third surface having a plurality of second electrodes arranged on the third surface, the fourth surface having a plurality of third electrodes and a plurality of fourth electrodes arranged on the fourth surface, each of the plurality of second electrodes being joined to each of the plurality of first electrodes; a fifth surface, and first and second side surfaces perpendicular to the fifth surface, the fifth surface being: a first front surface and a second front surface are divided by a recess having an opening on each of the first side surface and the second side surface, the recess having a first wall surface, a second wall surface, and a bottom surface, a plurality of fifth electrodes are arranged on the fifth surface, each of the plurality of fifth electrodes being joined to each of the plurality of third electrodes, an irregular circuit board having a plurality of electronic components housed in the recess and each of which is joined to each of the plurality of fourth electrodes of the planar circuit board, and a resin filling the recess, and the irregular circuit board has a distance between the first wall surface and the second wall surface of From the fifth surface side The bottom surface Continuously across the sides Small stomach .

[0006] An endoscope according to an embodiment of the present invention is an endoscope having an imaging unit at a tip of an insertion section, the imaging unit having a first surface and a second surface opposite to the first surface, including an imaging element, a semiconductor package having a plurality of first electrodes arranged on the second surface, a planar circuit board having a third surface and a fourth surface opposite to the third surface, a plurality of second electrodes arranged on the third surface, a plurality of third electrodes and a plurality of fourth electrodes arranged on the fourth surface, each of the plurality of second electrodes being joined to each of the plurality of first electrodes, a fifth surface, a first side surface perpendicular to the fifth surface and a second side surface perpendicular to the fifth surface, a side surface, the fifth surface being divided into a first front surface and a second front surface by a recess having openings on the first side surface and the second side surface, the recess having a first wall surface, a second wall surface and a bottom surface, a plurality of fifth electrodes being arranged on the fifth surface, each of the plurality of fifth electrodes being joined to each of the plurality of third electrodes, an irregular circuit board being joined to each of the plurality of fourth electrodes of the planar circuit board, a plurality of electronic components being accommodated in the recess, and a resin filling the recess, the irregular circuit board being such that a distance between the first wall surface and the second wall surface is From the fifth surface side The bottom surface Continuously across the sides Small stomach .

[0007] A method for manufacturing an imaging unit according to an embodiment of the present invention includes a semiconductor package having a first surface and a second surface opposite to the first surface, the semiconductor package including an imaging element, the semiconductor package having a plurality of first electrodes arranged on the second surface; a planar circuit board having a third surface and a fourth surface opposite to the third surface, the third surface having each of the plurality of first electrodes and a plurality of second electrodes joined thereto, and the fourth surface having a plurality of third electrodes and a plurality of fourth electrodes arranged thereon; a fifth surface, and a first side surface and a second side surface perpendicular to the fifth surface, the fifth surface being divided into a first front surface and a second front surface by a recess having an opening on each of the first side surface and the second side surface, the recess having a first wall surface, a second wall surface and a bottom surface, and a distance between the first wall surface and the second wall surface being: From the fifth surface side The bottom surface Continuously across the sides Small, the fifth face Complex a deformed circuit board on which a plurality of fifth electrodes are arranged, a plurality of electronic components are bonded to the plurality of fourth electrodes of the planar circuit board, each of the plurality of first electrodes of the semiconductor package is bonded to each of the plurality of second electrodes of the planar circuit board, each of the plurality of third electrodes of the planar circuit board is bonded to each of the plurality of fifth electrodes of the deformed circuit board, resin is injected between the plurality of electronic components accommodated in the recess and the first wall surface, and the resin is cured. Effect of the Invention

[0008] According to the embodiments of the present invention, it is possible to provide a highly reliable imaging unit, a highly reliable endoscope, and a method for manufacturing a highly reliable imaging unit. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an imaging unit according to the first embodiment. [Diagram 2] FIG. 2 is an exploded view of the imaging unit according to the first embodiment. [Diagram 3] FIG. 3 is a rear view of the planar circuit board of the imaging unit of the first embodiment. [Figure 4] FIG. 4 is a side view of the imaging unit of the first embodiment. [Diagram 5] FIG. 5 is a flowchart of a method for manufacturing the imaging unit of the first embodiment. [Figure 6] FIG. 6 is a perspective view for explaining a manufacturing method of the imaging unit of the first embodiment. [Figure 7] FIG. 7 is a cross-sectional view for explaining a manufacturing method of the imaging unit of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view of the imaging unit of the first embodiment. [Figure 9] FIG. 9 is a rear view of the planar circuit board of the imaging unit according to the first modification of the first embodiment. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of an endoscope according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment An imaging unit 1 of the present embodiment will be described with reference to FIGS.

[0011] The drawings based on the embodiments are schematic. The relationship between the thickness and width of each part in the drawings, the thickness ratio of each part, etc. are different from the actual ones. The drawings also include parts with different dimensional relationships and ratios. Some components are not shown and not labeled. The direction in which light is incident is called "front" and the opposite direction to "front" is called "rear".

[0012] The imaging unit 1 of this embodiment includes a semiconductor package 10, a planar circuit board 20, an irregular circuit board 30, a plurality of electronic components 40, and a resin 50.

[0013] The semiconductor package 10 includes a cover glass 12 and an imaging element 11. The cover glass 12 has a first surface 10SA. The imaging element 11, the rear surface of which is bonded to the front surface of the cover glass 12, has a second surface 10SB, which is the rear surface. The imaging element 11, which is made of silicon as its base material, is a CMOS (Complementary Metal Oxide Semiconductor) light receiving element or a CCD (Charge Coupled Device).

[0014] A plurality of first electrodes 13 are disposed on the second surface 10SB. The first electrodes 13 are, for example, solder bumps. A driving signal and power are supplied to the imaging element 11 via the plurality of first electrodes 13. In addition, a subject image received by the imaging element 11 is converted into an electric signal and output as an imaging signal via the plurality of first electrodes 13.

[0015] The semiconductor package 10 may have a stacked element in which a plurality of semiconductor elements that perform primary processing of an imaging signal are stacked on the imaging element 11, and a plurality of first electrodes 13 may be disposed on the rear surface of the stacked element. A lens unit in which a plurality of optical elements are stacked may be disposed on the first surface 10SA of the semiconductor package 10.

[0016] The planar circuit board 20 has a third surface 20SA and a fourth surface 20SB opposite to the third surface 20SA. A plurality of second electrodes 21 are arranged on the third surface 20SA. As shown in FIG. 4, each of the second electrodes 21 is joined to each of the first electrodes 13 of the semiconductor package 10. A plurality of third electrodes 22 and a plurality of fourth electrodes 23 are arranged on the fourth surface 20SB.

[0017] A plurality of electronic components 40 are surface-mounted on each of the plurality of fourth electrodes 23. The plurality of electronic components 40 are, for example, chip capacitors having a substantially rectangular parallelepiped shape. A substantially rectangular parallelepiped shape is a rectangular parallelepiped with curved chamfered corners. In the imaging unit 1, all of the plurality of electronic components 40 are chip capacitors having a size of 0603 (long side 0.6 mm, short side 0.3 mm).

[0018] The irregular circuit board 30 has a fifth surface 30SA, a first side surface 30SS1 and a second side surface 30SS2 each perpendicular to the fifth surface 30SA, and a sixth surface 30SB opposite the fifth surface 30SA. The irregular circuit board 30 is a molded interconnect device (MID) manufactured by injection molding and having wiring and the like arranged on its surface. The base material of the MID is epoxy, liquid crystal polymer, polyimide, polycarbonate, and the like. The irregular circuit board 30, which is a MID, can be easily manufactured into a complex shape.

[0019] The fifth surface 30SA of the irregular circuit board 30 is divided into a first front surface 30SA1 and a second front surface 30SA2 by a recess T30 having openings on the first side surface 30SS1 and the second side surface 30SS2, respectively. The recess T30 is a groove having a first wall surface T30S1, a second wall surface T30S2, and a bottom surface T30SB. In other words, the irregular circuit board 30 has a first arm portion having a first front surface 30SA1 and a second arm portion having a second front surface 30SA2, and the inner surfaces of the two arms are the first wall surface T30S1 and the second wall surface T30S2, respectively. The width W at the opening of the recess T30, i.e., the distance between the first front surface 30SA1 and the second front surface 30SA2, is 1.2 mm.

[0020] A plurality of fifth electrodes 31 are disposed on the fifth surface 30SA (the first front surface 30SA1 and the second front surface 30SA2). Each of the plurality of fifth electrodes 31 is joined to each of the plurality of third electrodes 22 of the planar circuit board 20.

[0021] The electronic components 40 disposed on the fourth surface 20SB of the planar circuit board 20 are accommodated in the recesses T30 of the irregular circuit board 30.

[0022] A plurality of wiring layers 32 extending from the plurality of fifth electrodes 31 are disposed on each of a third side surface 30SS3 and a fourth side surface 30SS4 perpendicular to the first side surface 30SS1 and the second side surface 30SS2 of the irregular circuit board 30. A signal cable (not shown) is joined to each end of the plurality of wiring layers 32.

[0023] Resin 51 is disposed in the gap between the semiconductor package 10 and the planar circuit board 20, i.e., in the joint between the first electrode 13 and the second electrode 21. In order to efficiently fill the narrow and wide gaps with the resin 51, a notch C20 is provided in the third surface 20SA. Uncured, liquid resin 51 is injected into the gap from the notch C20 using a nozzle (not shown), and spreads between the semiconductor package 10 and the planar circuit board 20 due to interfacial tension.

[0024] In the recesses T30 of the irregular circuit board 30, that is, in the joints between the fourth electrodes 23 and the plurality of electronic components 40, a resin 50 is provided.

[0025] The resin 50 is injected into the recess T30 as an uncured liquid resin 50, similar to the resin 51. However, it is not easy to fill the spaces between the small electronic components 40 housed in the small recess T30 with the resin 50. For example, if the electronic components 40 are arranged symmetrically in the vertical and horizontal directions, the electronic components 40 will obstruct the flow of the resin 50. This may result in a cavity in which the resin 50 is not placed, which may reduce reliability. In addition, the time required to inject the resin 50 may be increased. Furthermore, when the resin 50 is injected using a nozzle, the opening serving as the injection hole is small, so that the resin 50 may overflow around the recess T30, causing the external dimensions of the imaging unit 1 to increase.

[0026] The imaging unit 1 has the following features in terms of the arrangement of the multiple electronic components 40 housed in the recess T30.

[0027] The first electronic component 41 closest to the first side surface 30SS1 is disposed with its long side parallel to the first side surface 30SS1. The first electronic component 41 has a first distance L1 (0.4 mm) from the first wall surface T30S1 that is greater than a third distance L3 (0.2 mm) from the second wall surface T30S2. That is, the imaging unit 1 has an opening on the first side surface 30SS1 side that serves as an injection hole for injecting the resin 50.

[0028] The plurality of electronic components 42-45 other than the first electronic component 41 are arranged with their long sides perpendicular to the first side surface 30SS1.

[0029] The maximum distance between each of the multiple electronic components 42-45 other than the first electronic component 41 and the adjacent wall surface out of the first wall surface T30S1 or the second wall surface T30S2 is referred to as a second distance L2.

[0030] Electronic components 42 and 44 are closer to the first wall surface T30S1 than to the second wall surface T30S2. The distance between electronic components 42 and 44 and the first wall surface T30S1 is a second distance L2 (0.2 mm). Electronic components 43 and 45 are closer to the second wall surface T30S2 than to the first wall surface T30S1. The distance between electronic components 43 and 45 and the second wall surface T30S2 is the same as the second distance L2.

[0031] Moreover, the maximum distance among the distances between the multiple electronic components 40 (41-45) is referred to as a fourth distance L4. The distance between electronic components 42 and 43 is fourth distance L4 (0.25 mm). The distance between electronic components 44 and 45 is also fourth distance L4. The distance between electronic components 43 and 45 and the distance between electronic components 44 and 42 are also 0.2 mm, which is smaller than fourth distance L4.

[0032] The fifth distance L5 between the electronic components 40 (41-45) and the bottom surface T30SB of the recess T30 is 0.25 mm.

[0033] In the imaging unit 1 configured as described above, the first distance L1 (0.4 mm) between the first electronic component 41 and the first wall surface T30S1 is wider than the widths of the other gaps (the second distance L2, the third distance L3, the fourth distance L4, and the fifth distance L5) in the internal space of the recess T30.

[0034] 4, the first wall surface T30S1 and the second wall surface T30S2 of the recess T30 of the irregular circuit board 30 are inclined with respect to the fifth surface 30SA. That is, the angle θ of the first wall surface T30S1 and the second wall surface T30S2 with respect to the fifth surface 30SA is 100 degrees, which is greater than 90 degrees. In other words, the distance W between the first wall surface T30S1 and the second wall surface T30S2 (the width of the recess T30, which is a cutout) becomes smaller toward the bottom surface T30SB.

[0035] As described later, in the imaging unit 1, the resin 50 injected between the first electronic component 41 and the first wall surface T30S1 spreads efficiently into the internal space of the recess T30 due to interfacial tension. Therefore, the imaging unit 1 is highly reliable because it is difficult for a cavity in the recess T30 where the resin 50 is not disposed to occur.

[0036] <Manufacturing method of imaging unit> A method for manufacturing the imaging unit 1 will be described with reference to the flow chart of FIG.

[0037] <Step S10> A semiconductor package 10, a planar circuit board (planar wiring board) 20, and an irregular circuit board (three-dimensional wiring board) 30 are fabricated.

[0038] The semiconductor package 10 has a first surface 10SA and a second surface 10SB opposite to the first surface 10SA. The semiconductor package 10 includes an imaging element 11 and a cover glass 12, and a plurality of first electrodes 13 are disposed on the second surface 10SB.

[0039] The planar circuit board 20 has a third surface 20SA and a fourth surface 20SB opposite to the third surface 20SA. The third surface 20SA is provided with a plurality of first electrodes 13 and a plurality of second electrodes 21 to which the first electrodes 13 are joined. The fourth surface 20SB is provided with a plurality of third electrodes 22 and a plurality of fourth electrodes 23.

[0040] The irregular circuit board has a fifth surface 30SA, and a first side surface 30SS1 and a second side surface 30SS2 perpendicular to the fifth surface 30SA. The fifth surface 30SA is divided into a first front surface 30SA1 and a second front surface 30SA2 by a recess T30 having openings on the first side surface 30SS1 and the second side surface 30SS2, respectively. The recess T30, which is a cutout, has a first wall surface T30S1, a second wall surface T30S2, and a bottom surface T30SB. The interval W between the first wall surface T30S1 and the second wall surface T30S2 becomes smaller toward the bottom surface T30SB. A plurality of fifth electrodes 31 are arranged on the fifth surface 30SA.

[0041] The angle θ of the first wall surface T30S1 and the second wall surface T30S2 with respect to the fifth surface 30SA is preferably more than 90 degrees and less than 120 degrees, and particularly preferably more than 95 degrees and less than 110 degrees. If the angle θ is within the above range, the necessary number of electronic components 40 can be accommodated in the recess T30, and the resin 50 can be efficiently filled into the recess T30.

[0042] <Step S20> A plurality of electronic components 40 are bonded to the plurality of fourth electrodes 23 of the planar circuit board 20 .

[0043] Among the multiple electronic components 40, the first electronic component 41 is closest to the first side surface 30SS1. As already described, the multiple electronic components 40 are arranged such that the first distance L1 between the first electronic component 41 and the first wall surface T30S1 is wider than the widths of the other multiple gaps (the second distance L2, the third distance L3, the fourth distance L4, and the fifth distance L5) in the internal space of the recess T30.

[0044] <Step S30> Each of the first electrodes 13 of the semiconductor package 10 is bonded to each of the second electrodes 21 of the planar circuit board 20. Each of the third electrodes 22 of the planar circuit board 20 is bonded to each of the fifth electrodes 31 of the irregular circuit board 30.

[0045] Incidentally, the semiconductor package 10 and the planar circuit board 20 may be bonded together prior to step S20.

[0046] <Step S40> As shown in FIG. 6, resin 50 is injected into recess T30 using nozzle 55 from between first electronic component 41 and first wall surface T30S1.

[0047] The first distance L1 (0.4 mm) between the first electronic component 41 and the first wall surface T30S1 is wider than the widths of the other gaps (the second distance L2, the third distance L3, the fourth distance L4, and the fifth distance L5) in the internal space of the recess T30. Therefore, as shown in FIG. 7, the resin 50 spreads into the multiple gaps in the internal space of the recess T30 due to the interfacial tension.

[0048] The first distance L1 is preferably greater than 0.3 mm in order to efficiently inject the resin 50. The second distance L2, the third distance L3, the fourth distance L4, and the fifth distance L5 are preferably less than 0.3 mm because the resin 50 tends to spread due to interfacial tension.

[0049] <Step S50> The resin 50 is cured by, for example, a heat curing method or a combined ultraviolet curing / heat curing method.

[0050] According to this manufacturing method, not only can the resin 50 be reliably filled, but also the resin 50 can be filled in a short time. Furthermore, there is no risk that the resin 50 will overflow around the recess T30 during injection, causing the external dimensions of the imaging unit 1 to increase.

[0051] Although not explained, in step S40, resin 51 is injected into the gap between the semiconductor package 10 and the planar circuit board 20, and in step S50, the resin 51 is cured.

[0052] It is efficient to continuously inject the resin 50 and the resin 51. For this reason, it is preferable that the notch C20 of the planar circuit board 20, which serves as the inlet for the resin 51, is located on the first side surface 30SS1 side where the inlet for the resin 50 is located.

[0053] It is more preferable that the resin 50 and the resin 51 are the same resin. In the imaging unit 1 in which the resin 50 is disposed in the gap between the semiconductor package 10 and the planar circuit board 20, the resin 50 is filled in the corner cutout C20 on the first side surface 30SS1 side of the third surface 20SA of the planar circuit board 20 into which the resin 50 has been injected.

[0054] That is, in the imaging unit 1, it is preferable that the third surface 20SA of the planar circuit board 20 has a notch filled with the resin 50 at a corner on the first side surface 30SS1 side.

[0055] <Modification of the first embodiment> Imaging units 1A and 1B of the modified example of the first embodiment are similar to imaging unit 1 and have the same effects as imaging unit 1. For this reason, components having the same functions as imaging unit 1 are given the same reference numerals as imaging unit 1 and descriptions thereof will be omitted.

[0056] <Modification 1 of the First Embodiment> 8, the bottom surface T30SB of the recess T30 of the irregular circuit board 30 is inclined with respect to the fifth surface 30SA. That is, the fifth distance L5 (depth H30 of the recess T30), which is the distance between the multiple electronic components 40 and the bottom surface T30SB, becomes continuously smaller from the first side surface 30SS1 side toward the second side surface 30SS2 side.

[0057] Therefore, in the imaging unit 1A, the resin 50 injected from the first side surface 30SS1 side spreads more easily to the second side surface 30SS2 side than in the imaging unit 1.

[0058] <Modification 2 of the First Embodiment> An imaging unit 1B of this modified example shown in FIG. 9 includes a plurality of electronic components 40 of different sizes, and a first electronic component 41 is the largest of the plurality of electronic components 40.

[0059] The electronic components 41, 42, and 43 are chip capacitors of size 0603 (long side 0.6 mm, short side 0.3 mm). The electronic components 44-46 are chip capacitors of size 0402 (long side 0.4 mm, short side 0.2 mm).

[0060] The basic arrangement of the multiple electronic components 40 in the imaging unit 1B is set under the same conditions as the arrangement of the multiple electronic components 40 in the imaging unit 1. However, the electronic component closest to the first side surface 30SS1 is the first electronic component 41, which is the largest among the multiple electronic components 40 (41-46).

[0061] The first distance L1 (0.4 mm) between the first electronic component 41 and the first wall surface T30S1 is wider than the widths of the other gaps (the second distance L2, the third distance L3, the fourth distance L4, and the fifth distance L5) in the internal space of the recess T30.

[0062] The imaging unit of the present invention may have three or more different types of electronic components 40 of different sizes. The electronic components 40 are not limited to chip capacitors, and may include electronic components with different functions, such as chip inductors and IC chips.

[0063] <Second embodiment> The endoscope 5 (5A, 5B) of this embodiment shown in Figure 10 includes an insertion section 9B having an imaging unit 1 (1A, 1B) disposed at a tip 9A, an operating section 9C disposed at the base end side of the insertion section 9B, and a universal cord 9D extending from the operating section 9C.

[0064] The endoscope 5 is equipped with the imaging unit 1 (1A, 1B) which is highly reliable and easy to manufacture, and therefore is highly reliable and easy to manufacture.

[0065] The present invention is not limited to the above-described embodiments and modifications, and various modifications, combinations, and applications are possible without departing from the spirit and scope of the invention. [Explanation of symbols]

[0066] 5. Endoscope 9A...Tip 9B Insertion part 9C...Operation unit 9D... Universal Code 10. Semiconductor packages 10SA...First side 10SB...Second side 11. Imaging element 12. Cover glass 13... First electrode 20...Flat circuit board (plane wiring board) 20SA...Third Side 20SB...The Fourth Side 21... Second electrode 22...Third electrode 23...Fourth electrode 30... Irregular circuit board (three-dimensional wiring board) 30SA···The 5th Side 30SA1...1st front 30SA2...Second front 30SB...6th Side 30SS1...First side 30SS2...Second side 30SS3: The third aspect 30SS4...The fourth side 31...5th electrode 32...Wiring layer 40(41-46) Electronic components 41...First electronic component 50...Resin 51...Resin 55 Nozzle

Claims

1. a semiconductor package having a first surface and a second surface opposite to the first surface, the semiconductor package including an image sensor, and a plurality of first electrodes disposed on the second surface; a planar circuit board having a third surface and a fourth surface opposite to the third surface, a plurality of second electrodes arranged on the third surface, a plurality of third electrodes and a plurality of fourth electrodes arranged on the fourth surface, each of the second electrodes being joined to each of the first electrodes; an irregular circuit board having a fifth surface and first and second side surfaces perpendicular to the fifth surface, the fifth surface being divided into a first front surface and a second front surface by a recess having openings on the first and second side surfaces, the recess having a first wall surface, a second wall surface and a bottom surface, a plurality of fifth electrodes being disposed on the fifth surface, each of the plurality of fifth electrodes being joined to a respective one of the plurality of third electrodes; a plurality of electronic components joined to the plurality of fourth electrodes of the planar circuit board and accommodated in the recess; A resin filling the recess, The imaging unit according to claim 1, wherein the irregular circuit board has a distance between the first wall surface and the second wall surface that continuously decreases from the fifth surface side to the bottom surface side.

2. 2. The imaging unit according to claim 1, wherein a first distance between a first electronic component among the plurality of electronic components that is closest to the first side surface and the first wall surface is greater than a maximum second distance between each of the plurality of electronic components other than the first electronic component and a respective adjacent wall surface of the first wall surface or the second wall surface.

3. 3. The imaging unit according to claim 2, wherein the first distance is greater than a third distance between the first electronic component and the second wall surface.

4. 4. The imaging unit according to claim 3, wherein the first distance is greater than a maximum fourth distance among a plurality of distances between the plurality of electronic components.

5. 5. The imaging unit according to claim 4, wherein the first distance is greater than a maximum distance among fifth distances between the plurality of electronic components and the bottom surface of the recess.

6. 6. The imaging unit according to claim 5, wherein the bottom surface of the recess is inclined with respect to the fifth surface such that the fifth distance becomes smaller from the first side surface side toward the second side surface side.

7. 3. The imaging unit according to claim 2, wherein the first electronic component is arranged with a long side parallel to the first side surface, and each of the plurality of electronic components other than the first electronic component is arranged with a long side perpendicular to the first side surface.

8. 3. The imaging unit according to claim 2, wherein the plurality of electronic components are the same size.

9. The electronic components are different in size.

3. The imaging unit according to claim 2, wherein the first electronic component is the largest among the plurality of electronic components.

10. 2. The imaging unit according to claim 1, wherein the third surface of the planar circuit board has a notch filled with resin at a corner on the first side surface side.

11. An endoscope having an imaging unit at a tip of an insertion section, The imaging unit is a semiconductor package having a first surface and a second surface opposite to the first surface, the semiconductor package including an image sensor, and a plurality of first electrodes disposed on the second surface; a planar circuit board having a third surface and a fourth surface opposite to the third surface, a plurality of second electrodes arranged on the third surface, a plurality of third electrodes and a plurality of fourth electrodes arranged on the fourth surface, each of the second electrodes being joined to each of the first electrodes; an irregular circuit board having a fifth surface and first and second side surfaces perpendicular to the fifth surface, the fifth surface being divided into a first front surface and a second front surface by a recess having openings on the first and second side surfaces, the recess having a first wall surface, a second wall surface and a bottom surface, a plurality of fifth electrodes being disposed on the fifth surface, each of the plurality of fifth electrodes being joined to a respective one of the plurality of third electrodes; a plurality of electronic components joined to the plurality of fourth electrodes of the planar circuit board and accommodated in the recess; A resin filling the recess, An endoscope, comprising: said irregular circuit board; a space between said first wall surface and said second wall surface which space is continuously reduced from said fifth surface side to said bottom surface side.

12. a semiconductor package having a first surface and a second surface opposite to the first surface, the semiconductor package including an image sensor, and a plurality of first electrodes disposed on the second surface; a flat circuit board having a third surface and a fourth surface opposite to the third surface, the third surface being provided with a plurality of first electrodes and a plurality of second electrodes joined thereto, and the fourth surface being provided with a plurality of third electrodes and a plurality of fourth electrodes; a fifth surface, and a first side surface and a second side surface perpendicular to the fifth surface, the fifth surface being divided into a first front surface and a second front surface by a recess having openings on the first side surface and the second side surface, the recess having a first wall surface, a second wall surface and a bottom surface, the distance between the first wall surface and the second wall surface becoming continuously smaller from the fifth surface side to the bottom surface side, and a plurality of fifth electrodes being disposed on the fifth surface; bonding a plurality of electronic components to the plurality of fourth electrodes of the planar circuit board; bonding each of the first electrodes of the semiconductor package to each of the second electrodes of the planar circuit board, and bonding each of the third electrodes of the planar circuit board to each of the fifth electrodes of the irregular circuit board; Injecting a resin between the plurality of electronic components accommodated in the recess and the first wall surface; A method for manufacturing an imaging unit, comprising: curing the resin.

Images