JP7585934B2 - Manufacturing method of imaging module - Google Patents

Description

The present invention relates to a method for manufacturing an imaging module to be provided in, for example, a camera head of an endoscope.

Conventionally, endoscopes for imaging the inside of a subject's body are equipped with an imaging module having a very small image sensor (imaging element) in a camera head that is inserted through the subject's mouth or nose. Image signals from the image sensor are sent to a camera control unit placed outside the body via a cable having multiple electric wires. Specific examples of image sensors include CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors.

In recent years, endoscopic camera heads have been made smaller and thinner to reduce the burden on subjects, and image sensors, for example, 1 mm square, are now being used. Since it is extremely difficult to directly connect the electrodes of such image sensors to the electric wires of a cable, the image sensor and the electric wires are electrically connected via a flexible substrate having pads that are connected to the electrodes of the image sensor, as described in Patent Documents 1 and 2, for example.

In the endoscope described in Patent Document 1, a rectangular flexible substrate is bent at two points so as to form a roughly triangular shape in a side view, and conductors are connected to both longitudinal ends of the first main surface that is on the outside of the bend.

In the endoscope described in Patent Document 2, the flexible board is bent in two places, just like the one described in Patent Document 1, but in order to reduce the radius of curvature of the bent parts, the bent parts have a flying lead structure (a structure consisting only of the wiring pattern with the base and coverlay removed).

JP 2014-94237 A (see FIG. 5, paragraph [0022]) JP 2021-35466 A (see FIG. 2, paragraphs [0033] to [0037])

In the endoscope described in Patent Document 1, since the conductors are connected to the outside of the bend in the flexible substrate, it is necessary to provide a sufficient gap between the connection part of the conductors and the surrounding components to prevent the connection part from interfering with the surrounding components and causing breakage. In addition, if the radius of curvature of the bent part of the flexible substrate becomes small, the pattern formed by etching the conductive film becomes stretched on the outer part of the bent part and becomes prone to breakage, so the radius of curvature of the bent part must be large enough to prevent such breakage. These constraints are an obstacle to miniaturizing endoscopes.

In the endoscope described in Patent Document 2, it is possible to reduce the radius of curvature of the bent portion of the flexible substrate and thereby reduce the size of the camera head, but the processing costs for making the bent portion into a flying lead structure are high. There is also a risk of the strength being reduced in the part with the flying lead structure.

The present invention was made in consideration of the above circumstances, and its purpose is to provide an imaging module and a manufacturing method thereof that can be made smaller while minimizing increases in cost and decreases in strength of the flexible substrate that connects the imaging element to multiple electric wires.

The present invention aims to solve the above problems by providing an imaging module comprising: a flexible substrate having a plurality of electrode connection pads formed on one side of a flexible, plate-like insulating substrate and a plurality of electric wire connection pads formed on the other side of the insulating substrate; an imaging element having a plurality of electrodes connected to the plurality of electrode connection pads respectively, for capturing an image of a subject; and a cable having a plurality of electric wires connected to the plurality of electric wire connection pads respectively, wherein the flexible substrate is provided with the plurality of electric wire connection pads at both ends in a predetermined direction on the other side, and the plurality of electrode connection pads are provided in a central portion in the predetermined direction on the one side, and the both ends on the other side of the insulating substrate are curved so as to face each other.

In order to solve the above problems, the present invention also provides a method for manufacturing the imaging module, which includes an arrangement step of bending the flexible substrate to arrange the multiple electric wire connection pads in a line, and a connection step of connecting the multiple electric wire connection pads and the multiple electric wires by pulse heat.

The imaging module and manufacturing method thereof according to the present invention make it possible to reduce the size while minimizing the increase in cost and decrease in strength of the flexible substrate that connects the imaging element to multiple electric wires.

1A shows an endoscopic camera head having an imaging module according to an embodiment of the present invention, in which (a) is an end view showing the tip surface of the camera head, and (b) is a cross-sectional view showing the inside of the camera head along line A-A in (a). FIG. 2 is a perspective view showing an imaging module. 1A is a configuration diagram of an imaging module seen from the side, and FIG. 1B is a rear view of an imaging element. 3A and 3B are plan views showing a flexible substrate, in which FIG. 3A shows one surface of an insulating substrate, and FIG. 3B shows the other surface of the insulating substrate. FIG. 2 is a perspective cross-sectional view showing a part of a flexible substrate. 1A shows a flexible substrate on which first to fourth electric wire connection pads are arranged in a row by an arrangement process, FIG. 1B shows a state in which the core wires of the first to fourth electric wires are arranged overlappingly on the first to fourth electric wire connection pads, and FIG. 1C is an explanatory diagram showing a part of a pulse heat unit that performs connection by a pulse heat method. 10A and 10B are plan views showing a flexible substrate according to a modified example, and FIG. 10C is a plan view showing a flexible substrate on which first to fourth electric wire connection pads are arranged in a row by an arrangement step. FIG. 11 is an explanatory diagram showing a connecting process by pulse heat according to a modified example.

(Configuration of endoscope camera head)
1 shows an endoscopic camera head having an imaging module according to an embodiment of the present invention, in which (a) is an end view showing the tip surface of the camera head, and (b) is a cross-sectional view taken along line A-A in (a) showing the inside of the camera head.

This camera head 1 is composed of an imaging module 10 having a lens unit 2, a cylindrical external cylinder 11 made of hard resin that houses the imaging module 10, and a cover body 12 that closes the tip surface of the external cylinder 11. In addition, a tube 13 that guides a liquid such as saline to the area to be imaged is inserted into the camera head 1.

The cover body 12 is provided with a first through hole 121 into which the lens unit 2 is fitted and fixed, a second through hole 122 into which the tube 13 is fitted and fixed, and an irradiation window 123 that emits irradiation light that irradiates the imaging target area. The irradiation light is guided to the irradiation window 123 by an optical fiber (not shown). Note that instead of irradiating the imaging target area with light guided by the optical fiber, a small LED (light emitting diode) may be placed inside the camera head 1, and the light emitted from this LED may be radiated from the irradiation window 123.

(Configuration of imaging module)
Fig. 2 is a perspective view showing the imaging module 10. Fig. 3(a) is a configuration diagram of the imaging module 10 seen from the side, and Fig. 3(b) is a rear view of the imaging element 4.

The imaging module 10 includes a lens unit 2, a flexible substrate 3 used as a wiring member, an imaging element 4 disposed between the lens unit 2 and the flexible substrate 3, and a cable 5 for transmitting an image signal from the imaging element 4. The lens unit 2, the flexible substrate 3, and the imaging element 4 are installed in the camera head 1.

The lens unit 2 has a cylindrical body 21, a transparent cover 22 fixed to the tip of the body 21, and multiple lenses 23-26 arranged inside the body 21. The tip of the body 21 is fitted and fixed into the first through-hole 121 of the cover body 12, and the image sensor 4 is attached to the rear end. The multiple lenses 23-26 form an image of the subject on the image sensor 4.

The imaging element 4 is, for example, a CCD image sensor or a CMOS image sensor. The imaging element 4 captures an image of the subject formed by the multiple lenses 23-26, and outputs an image signal obtained by converting the captured image into an electrical signal. The image signal is sent via a cable 5 to an image processing device installed outside the subject's body. The image processing device decodes the image signal and displays the image on a display.

As shown in FIG. 3(b), the image sensor 4 has first to fourth electrodes 421 to 424 provided on the back surface 41a (the surface opposite the lens unit 2) of the element body 41. The first electrode 421 is, for example, a signal output electrode that outputs an image signal, and the second electrode 422 is, for example, a clock output electrode that outputs a clock signal synchronized with the image signal. The third electrode 423 is, for example, a power supply electrode for inputting operating power, and the fourth electrode 424 is, for example, a ground electrode.

The back surface 41a of the element body 41 is a plane perpendicular to the optical axis 20 (shown in FIG. 1) of the lens unit 2, and the first to fourth electrodes 421 to 424 are provided protruding from the back surface 41a of the body 41. The first to fourth electrodes 421 to 424 are arranged in two rows so that the line segment connecting their respective center points forms a rectangle. The size of the body 41 when viewed along the optical axis 20 is, for example, 1 mm square.

The cable 5 has a tubular sheath 50 and first to fourth electric wires 51 to 54 housed in the sheath 50. The first to fourth electric wires 51 to 54 are insulated electric wires in which core wires 511, 521, 531, and 541 made of a stranded wire in which a plurality of strands are twisted together are covered with insulators 512, 522, 532, and 542. The first to fourth electric wires 51 to 54 are not limited to insulated electric wires, and various known forms can be used. For example, the fourth electric wire 54 connected to the fourth electrode 424 may be a drain wire made of a metal conductor not covered with an insulator, and the other first to third electric wires 51 to 53 may be coaxial wires without a jacket. In this case, noise resistance can be improved by contacting the outer conductors of the first to third electric wires 51 to 53 as shield conductors and electrically grounding them by contacting them with the fourth electric wire 54 (drain wire).

The flexible substrate 3 has an insulating substrate 30 made mainly of an insulating resin such as polyimide. The insulating substrate 30 is flexible and curved at two points and disposed inside the outer tube 11. The thickness of the insulating substrate 30 is preferably 0.165 mm or less, and more preferably 0.100 mm or less. In the present embodiment, as an example, the thickness of the insulating substrate 30 is 86.5 μm. In addition, the flexible substrate 3 is disposed within a range that does not extend beyond the outer edge of the projection surface of the element body 41 when projected from the imaging element 4 side along a direction parallel to the optical axis 20 of the lens unit 2. Next, the configuration of the flexible substrate 3 will be described in detail with reference to FIG. 4 and FIG. 5.

Figure 4 is a plan view showing the flexible substrate 3, where (a) shows one surface 30a of the insulating substrate 30, and (b) shows the other surface 30b of the insulating substrate 30. Figure 5 is a perspective cross-sectional view showing a part of the flexible substrate 3 cut away.

Here, the one surface 30a is one of the main surfaces of the insulating substrate 30, and the other surface 30b is the other main surface of the insulating substrate 30 that is the back surface of the one surface 30a. The dashed lines shown in Fig. 4(a) are two first mountain fold lines MFL ₁ and two second mountain fold lines MFL _2. The dashed lines shown in Fig. 4(b) are two first valley fold lines VFL ₁ and two second valley fold lines VFL ₂ .

The insulating substrate 30 is rectangular in plan view. The length of the insulating substrate 30 in the longitudinal direction (long side direction) is 1 cm or less, and the width in the lateral direction (short side direction) perpendicular to the longitudinal direction is half or less of the longitudinal length. As an example, the length L of the insulating substrate 30 in the longitudinal direction is 5 mm, and the width W in the lateral direction is 1 mm. The longitudinal direction of the insulating substrate 30 corresponds to the specified direction in the claims.

The flexible substrate 3 has first to fourth electrode connection pads 311, 321, 331, 341 formed on one surface 30a of the insulating substrate 30, and first to fourth electric wire connection pads 315, 325, 335, 345 formed on the other surface 30b of the insulating substrate 30. The flexible substrate 3 is entirely covered on the one surface 30a and the other surface 30b with a coverlay (protective layer) (not shown) except for the portions where the first to fourth electrode connection pads 311, 321, 331, 341 and the first to fourth electric wire connection pads 315, 325, 335, 345 are formed.

The first to fourth electrodes 421 to 424 of the image sensor 4 are connected to the first to fourth electrode connection pads 311, 321, 331, and 341, respectively. The core wires 511, 521, 531, and 541 of the first to fourth electric wires 51 to 54 are connected to the first to fourth electric wire connection pads 315, 325, 335, and 345, respectively.

The first to fourth electrode connection pads 311, 321, 331, 341 are provided in the longitudinal center of one surface 30a of the insulating substrate 30. The first to fourth electric wire connection pads 315, 325, 335, 345 are provided at both longitudinal ends of the other surface 30b of the insulating substrate 30. More specifically, the first and second electric wire connection pads 315, 325 are provided at one longitudinal end of the other surface 30b of the insulating substrate 30, and the third and fourth electric wire connection pads 335, 345 are provided at the other longitudinal end.

As shown in FIG. 3, the flexible substrate 3 is curved so that both longitudinal ends of the other surface 30b of the insulating substrate 30 face each other. As a result, the first and second wire connection pads 315, 325 and the third and fourth wire connection pads 335, 345 of the flexible substrate 3 face each other on the inside of the curve of the insulating substrate 30, and no wire connection pads are formed on the one surface 30a, which is on the outside of the curve.

The flexible substrate 3 is curved in the longitudinal direction around the first mountain fold line MFL ₁ and the first valley fold line VFL ₁ along the short-side direction of the insulating base material 30, and the curvature of the curve is largest at the first mountain fold line MFL ₁ and the first valley fold line VFL _1. In Fig. 3, arrows indicate a first maximum curvature region 301 which is a region with the largest curvature on the first and second electric wire connection pads 315, 325 side from the region where the first to fourth electrode connection pads 311, 321, 331, 341 are formed, and a second maximum curvature region 302 which is a region with the largest curvature on the third and fourth electric wire connection pads 335, 345 side from the region where the first to fourth electrode connection pads 311, 321, 331, 341 are formed.

The first to fourth electrode connection pads 311, 321, 331, 341 are connected to the first to fourth wire connection pads 315, 325, 335, 345 by a wiring pattern including through holes. In more detail, the first electrode connection pad 311 and the first wire connection pad 315 are connected by the first one-side line 312, the first through hole 313, and the first other-side line 314. The second electrode connection pad 321 and the second wire connection pad 325 are connected by the second one-side line 322, the second through hole 323, and the second other-side line 324. The third electrode connection pad 331 and the third wire connection pad 335 are connected by a third one-side line 332, a third through hole 333, and a third other-side line 334. The fourth electrode connection pad 341 and the fourth wire connection pad 345 are connected by a fourth one-side line 342, a fourth through hole 343, and a fourth other-side line 344.

The first to fourth through holes 313, 323, 333, 343 penetrate between the one surface 30a and the other surface 30b of the insulating substrate 30. The first to fourth one-surface side traces 312, 322, 332, 342 connect the first to fourth electrode connection pads 311, 321, 331, 341 and the first to fourth through holes 313, 323, 333, 343 on the one surface 30a side. The first to fourth other-surface side traces 314, 324, 334, 344 connect the first to fourth through holes 313, 323, 333, 343 and the first to fourth electric wire connection pads 315, 325, 335, 345 on the other surface 30b side.

The first to fourth through holes 313, 323, 333, 343 are provided in the vicinity of the first to fourth electrode connection pads 311, 321, 331, 341, respectively. The first to fourth one-surface lines 312, 322, 332, 342 are formed in a range not exceeding the first mountain fold line MFL _1. That is, the first to fourth through holes 313, 323, 333, 343 are formed closer to the first to fourth electrode connection pads 311, 321, 331, 341 than the first maximum curvature portion 301 and the second maximum curvature portion 302, and no wiring pattern is formed on the one surface 30a of the first maximum curvature portion 301 and the second maximum curvature portion 302.

(Method of manufacturing an imaging module)
6, a method for manufacturing the imaging module 10 will be described. In particular, a process for connecting the first to fourth electric wires 51 to 54 of the cable 5 to the first to fourth electric wire connection pads 315, 325, 335, and 345 of the flexible substrate 3 will be described.

The first to fourth electric wires 51 to 54 of the cable 5 are connected to the first to fourth electric wire connection pads 315, 325, 335, and 345, respectively, through an arrangement process in which the flexible substrate 3 is bent to arrange the first to fourth electric wire connection pads 315, 325, 335, and 345 in a row, and a connection process using pulse heat that is performed after the arrangement process.

6A shows the flexible substrate 3 on which the first to fourth electric wire connection pads 315, 325, 335, and 345 are arranged in a row by the arrangement process. In this arrangement process, the flexible substrate 3 is mountain-folded at the two second mountain fold lines MFL ₂ (valley-folded at the two second valley fold lines VFL ₂ ) to arrange the first to fourth electric wire connection pads 315, 325, 335, and 345 in a row.

4(b), the two second valley fold lines _VFL2 are inclined in opposite directions at an angle of 45° with respect to the longitudinal direction of the insulating substrate 30. Of the two second valley fold lines _VFL2 , one second valley fold line _VFL2 intersects the first other-side line 314 and the second other-side line 324, and the other second valley fold line _VFL2 intersects the third other-side line 334 and the fourth other-side line 344.

Figure 6 (b) shows the state in which the core wires 511, 521, 531, and 541 of the first to fourth electric wires 51 to 54 are arranged on top of the first to fourth electric wire connection pads 315, 325, 335, and 345 that have been arranged in a row by the arrangement process.

Figure 6(c) is an explanatory diagram showing a part of the pulse heat unit 6 that performs the connection by the pulse heat method. The pulse heat unit 6 has a mounting table 61 on which the flexible board 3 and the first to fourth electric wires 51 to 54 as the connection objects are placed, and a heater tip 62 that moves up and down relative to the mounting table 61.

The flexible substrate 3 is placed on the flat mounting surface 61a of the mounting table 61. The heater tip 62 has a flat pressure surface 62a that faces the mounting surface 61a. When the heater tip 62 moves downward toward the mounting table 61, the flexible substrate 3 and the core wires 511, 521, 531, 541 of the first to fourth electric wires 51 to 54 are sandwiched between the mounting surface 61a and the pressure surface 62a and pressurized. The heater tip 62 also generates heat instantaneously when a current is supplied during pressure application. In other words, the pulse heat unit 6 connects the objects to be connected by simultaneously applying pressure and heating.

The first to fourth electric wire connection pads 315, 325, 335, 345 and the first to fourth electric wires 51 to 54 are connected by melting the cream solder that has been applied to the first to fourth electric wire connection pads 315, 325, 335, 345 in advance by heating with the heater tip 62. More specifically, the core wires 511, 521, 531, 541 of the first to fourth electric wires 51 to 54 are pressed against the first to fourth electric wire connection pads 315, 325, 335, 345 to which the cream solder has been applied by the heater tip 62, and a current is supplied to the heater tip 62 to heat it and melt the cream solder. Then, the current supply to the heater chip 62 is cut off and the molten solder solidifies, after which the heater chip 62 is moved upward relative to the mounting table 61, and the flexible substrate 3 and the first to fourth electric wires 51 to 54 are removed from the pulse heat unit 6.

Then, after the first to fourth electric wire connection pads 315, 325, 335, 345 and the first to fourth electric wires 51 to 54 are connected, the mountain fold at the second mountain fold line MFL ₂ (the valley fold at the second valley fold line VFL ₂ ) is returned to its original state. Then, the first to fourth electrode connection pads 311, 321, 331, 341 and the first to fourth electrodes 421 to 424 of the imaging element 4 are connected. This connection is performed by soldering using cream solder, for example. Note that the imaging element 4 may be connected to the flexible substrate 3 prior to the connection of the first to fourth electric wires 51 to 54.

(Effects of the embodiment)
According to the embodiment described above, since no electric wires are arranged on the outside of the bend of the flexible substrate 3, it is possible to reduce the size and diameter of the outer cylinder 11 of the camera head 1. Furthermore, since no wiring pattern is formed on one surface 30a of the first maximum curvature portion 301 and the second maximum curvature portion 302, the wiring pattern is not stretched by the bending of the insulating base material 30, and it is possible to bend the flexible substrate 3 with a large curvature. This also makes it possible to reduce the size and diameter of the outer cylinder 11 of the camera head 1. Furthermore, according to the present embodiment, the manufacturing process of the flexible substrate is not complicated, which increases costs and reduces strength, as in the case of adopting the above-mentioned flying lead structure.

(Modification)
Next, a modified example of the embodiment will be described with reference to Figures 7 and 8. In Figures 7 and 8, members and parts common to those described in the above embodiment are designated by the same reference numerals as those in Figures 1 to 6, and duplicated explanations will be omitted.

Figures 7(a) and (b) are plan views showing a flexible substrate 3A according to a modified example, where (a) shows one surface 30a of the insulating substrate 30, and (b) shows the other surface 30b of the insulating substrate 30. Figure 7(c) is a plan view showing a flexible substrate 3A in which the first to fourth electric wire connection pads 315, 325, 335, and 345 are arranged in a row by the arrangement process. Figure 8 is an explanatory diagram showing the connection process by pulse heat.

The flexible substrate 3A is generally configured in the same manner as the flexible substrate 3 according to the above embodiment, but the flexible substrate 3A has first to fourth protrusions 35 to 38 at both ends of the insulating substrate 30 in the longitudinal direction, and the first to fourth protrusions 35 to 38 have through holes 350, 360, 370, and 380 formed therein. The first to fourth protrusions 35 to 38 protrude from the portions where the first to fourth electric wire connection pads 315, 325, 335, and 345 are provided on both sides of the insulating substrate 30 in the lateral direction.

The first protrusion 35 protrudes in one short direction from the portion of the insulating substrate 30 where the first and second electric wire connection pads 315, 325 are provided, and the second protrusion 36 protrudes in the other short direction from the portion of the insulating substrate 30 where the first and second electric wire connection pads 315, 325 are provided. The third protrusion 37 protrudes in one short direction from the portion of the insulating substrate 30 where the third and fourth electric wire connection pads 335, 345 are provided, and the fourth protrusion 38 protrudes in the other short direction from the portion of the insulating substrate 30 where the third and fourth electric wire connection pads 335, 345 are provided.

In the arrangement process, the flexible substrate 3A is mountain-folded at the two second mountain fold lines MFL ₂ (valley-folded at the two second valley fold lines VFL ₂ ). When the first to fourth electric wire connection pads 315, 325, 335, 345 are arranged in a row, as shown in FIG. 7C, the through hole 360 of the second protrusion 36 and the through hole 380 of the fourth protrusion 38 communicate with each other.

In the connection process, as shown in FIG. 8, the protrusions 611, 612, and 613 provided on the mounting base 61 of the pulse heat unit 6A are inserted through the through hole 350 of the first protrusion 35, the through hole 370 of the third protrusion 37, and the through holes 360, 380 of the second and fourth protrusions 36, 38, respectively, to fix the flexible substrate 3A. The heater chip 62 has a recess 620 formed therein to avoid interference with the protrusion 613.

This fixing structure allows the flexible substrate 3A to be more stably fixed to the mounting base 61 and connected by pulse heat. The first to fourth protrusions 35 to 38 are cut off after the connection process.

The flexible board 3A, which has been connected to the first to fourth electric wires 51 to 54 in this manner, is accommodated in the external cylinder 11 of the camera head 1 together with the image sensor 4 in a curved state in two places, similar to the flexible board 3 in the above embodiment.

(Summary of the embodiment)
Next, the technical ideas grasped from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[1] A flexible substrate (3, 3A) having a plurality of electrode connection pads (311, 321, 331, 341) formed on one side (30a) of a flexible plate-like insulating substrate (30) and a plurality of electric wire connection pads (315, 325, 335, 345) formed on the other side (30b) of the insulating substrate (30), an imaging element (4) having a plurality of electrodes (421-424) respectively connected to the plurality of electrode connection pads (311, 321, 331, 341) for capturing an image of a subject, and a plurality of electrodes (421-424) connected to the plurality of electric wire connection pads (315, 325, 335, 345) and a cable (5) having a plurality of electric wires (51-54) connected to each other, the flexible substrate (3, 3A) has the plurality of electric wire connection pads (315, 325, 335, 345) at both ends in a predetermined direction (longitudinal direction) on the other side (30b), the plurality of electrode connection pads (311, 321, 331, 341) at the center in the predetermined direction on the one side (30a), and the both ends on the other side (30b) of the insulating base material (30) are curved so as to face each other.

[2] The imaging module (10) described in [1] above, in which each of the plurality of electrode connection pads (311, 321, 331, 341) and each of the plurality of electric wire connection pads (315, 325, 335, 345) are connected by a wiring pattern including through holes (313, 323, 333, 343) that penetrate between the one surface (30a) and the other surface (30b) of the insulating substrate (30), and the wiring pattern is not formed on the one surface (30a) of the portion (301, 302) of the flexible substrate (3, 3A) with the largest curvature.

[3] The wiring pattern includes a plurality of one-side lines (312, 322, 332, 342) that connect each of the plurality of electrode connection pads (311, 321, 331, 341) to the through holes (313, 323, 333, 343) on the one-side surface (30a), and a plurality of wire connection pads (315, 325, 335, 345) that connect each of the plurality of wire connection pads (315, 325, 335, 345) to the through holes (313, 323 The imaging module (10) described in [2] above has a plurality of other-side lines (314, 324, 334, 344) that connect the other side (30b) to the other side (30c), and the through holes (313, 323, 333, 343) are formed on the side of the electrode connection pads (311, 321, 331, 341) rather than the portion with the greatest curvature (301, 302).

[4] The imaging module (10) described in [1] to [3] above, wherein the flexible substrate (3, 3A) has a length of 1 cm or less in the specified direction.

[5] The imaging module (10) described in [1] to [4] above, in which the imaging element (4) and the flexible substrate (3, 3A) are installed in an endoscopic camera head (1).

[6] A method for manufacturing the imaging module (10) described in any one of [1] to [5] above, comprising an arrangement step of bending the flexible substrate (3, 3A) to arrange the plurality of electric wire connection pads (315, 325, 335, 345) in a line, and a connection step of connecting the plurality of electric wire connection pads (315, 325, 335, 345) to the plurality of electric wires (51 to 54) by pulse heat.

[7] The imaging module (10) described in [6] above, in which protrusions (35-38) with through holes (350, 360, 370, 380) are provided at both ends of the insulating substrate (30) in the predetermined direction, and in the placement process, protrusions (611-613) provided on the mounting base (61) of the pulse heat are inserted into the through holes (350, 360, 370, 380) to fix the flexible substrate (3A).

[8] The imaging module (10) described in [7] above, in which the protrusions (35-38) protrude from the portion where the multiple electric wire connection pads (315, 325, 335, 345) are provided on both sides in a direction perpendicular to the predetermined direction (short direction).

Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the embodiments described above. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

1... camera head 10... imaging module 3, 3A... flexible substrate 30... insulating substrate 30a... one side 30b... other side 311, 321, 331, 341... first to fourth electrode connection pads 312, 322, 332, 342... first to fourth one-side lines 313, 323, 333, 343... first to fourth through holes 314, 324, 3 34, 344...first to fourth other surface side lines 315, 325, 335, 345...first to fourth electric wire connection pads 35 to 38...first to fourth protrusions 350, 360, 370, 380...through hole 4...imaging elements 421 to 424...first to fourth electrodes 5...cables 51 to 54...first to fourth electric wires 61...mounting bases 611, 612, 613...protrusions

Claims (3)

a flexible substrate having a plurality of electrode connection pads formed on one surface of a flexible plate-like insulating base material and a plurality of electric wire connection pads formed on the other surface of the insulating base material;
an image sensor having a plurality of electrodes connected to the plurality of electrode connection pads, respectively, for capturing an image of a subject;
a cable having a plurality of electric wires respectively connected to the plurality of electric wire connection pads;
the flexible substrate is provided with the plurality of electric wire connection pads at both ends in a predetermined direction on the other surface, and the plurality of electrode connection pads are provided at a center portion in the predetermined direction on the one surface, and the both ends on the other surface of the insulating base material are curved so as to face each other.
A method for manufacturing an imaging module, comprising the steps of:
a placement step of bending the flexible substrate to place the plurality of electric wire connection pads in a line;
a connecting step of connecting the plurality of electric wire connection pads and the plurality of electric wires by pulse heat;
A manufacturing method of an imaging module comprising the steps of: a protruding portion having a through hole formed therein is provided on both ends of the insulating base material in the predetermined direction;
In the positioning step, a protrusion provided on a mounting base of the pulse heater is inserted into the through hole to fix the flexible substrate.
A method for manufacturing the imaging module according to claim 1 . the protruding portion protrudes from a portion where the plurality of electric wire connection pads are provided on both sides in a direction perpendicular to the predetermined direction;
A method for manufacturing the imaging module according to claim 2 .

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