Endoscope imaging module

Abstract

To provide an imaging module for endoscopes capable of reducing a diameter of an insertion part of an endoscope by reducing a width of FPC.SOLUTION: An imaging module for an endoscope comprises an image pick-up device having a connection end face, a first terminal row and a second terminal row formed on the connecting end face, and an FPC including a base material having a first surface and a second surface, a first circuit pattern formed on the first surface, and a second circuit pattern formed on the second surface. A tip end of the FPC is inserted between the first terminal row and the second terminal row, at least a part of the first circuit pattern is electrically connected to the first terminal row, at least a part of the second circuit pattern is electrically connected to the second terminal row, and when viewed from a thickness direction of the FPC, a width of the connecting end face is A and a width of the tip end of the FPC is B, A≥B is satisfied, and the tip end of the FPC is disposed in the insertion part.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present invention relates to an imaging module for an endoscope. 【Background Art】 【0002】 Patent Document 1 discloses an imaging module for an endoscope including an image pickup device and an FPC. The image pickup device is disposed at the tip of the insertion portion of the endoscope and captures an image of a subject. The FPC is inserted into a cable tube constituting the insertion portion and electrically connects the image pickup device to other members. On one surface of the FPC, a plurality of electrical signal lines are arranged side by side in a row, and the tip portions of each electrical signal line are connected to the image pickup device. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2011-125564 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 The insertion portion of the endoscope is required to have a smaller diameter. In order to reduce the diameter of the insertion portion, it is necessary to reduce the width of the FPC. However, in the configuration of Patent Document 1, electrical signal lines are arranged only on one surface of the FPC, and there is a limit in reducing the width of the FPC. 【0005】 In view of such circumstances, the present invention is made, and an object thereof is to provide an imaging module for an endoscope capable of reducing the diameter of the insertion portion of the endoscope by reducing the width of the FPC. 【Means for Solving the Problems】 【0006】 To solve the above problems, Embodiment 1 of the present invention provides an imaging module for endoscopes disposed inside an endoscope having an insertion section, comprising: an imaging sensor having a connecting end face; a first terminal row and a second terminal row formed on the connecting end face; a substrate having a first surface and a second surface; and an FPC having a first circuit pattern formed on the first surface and a second circuit pattern formed on the second surface, wherein the tip of the FPC is inserted between the first terminal row and the second terminal row, at least a portion of the first circuit pattern is electrically connected to the first terminal row, at least a portion of the second circuit pattern is electrically connected to the second terminal row, and when viewed from the thickness direction of the FPC, if the width of the connecting end face is A and the width of the tip of the FPC is B, then A ≥ B is satisfied, and the tip of the FPC is disposed inside the insertion section. 【0007】 Aspect 2 of the present invention is an imaging module for an endoscope according to aspect 1, wherein the FPC has a narrow portion including the tip and a wide portion, and when viewed from the thickness direction, the width of at least a part of the wide portion is greater than the width of the tip, and a connecting portion for connection to a connector is provided in the wide portion. 【0008】 A third aspect of the present invention is an imaging module for an endoscope according to aspect 1 or 2, wherein the substrate comprises a conductive shield layer and a first insulating layer and a second insulating layer disposed on both sides of the shield layer, the first surface being the surface of the first insulating layer and the second surface being the surface of the second insulating layer. 【0009】 Aspect 4 of the present invention is an imaging module for endoscopes according to aspect 3, wherein one of the first and second terminal rows includes a video signal terminal and the other includes a clock signal terminal. 【0010】 Aspect 5 of the present invention is an imaging module for an endoscope according to aspect 1, wherein the FPC has a constricted portion located opposite the image sensor at the tip, the substrate at the tip and the constricted portion has a plurality of layers, the FPC has a third circuit pattern and a fourth circuit pattern located in different layers of the plurality of layers, at least a portion of the first circuit pattern is electrically connected to one terminal of the first terminal row, at least a portion of the third circuit pattern is electrically connected to another terminal of the first terminal row via a via formed at the tip, at least a portion of the second circuit pattern is electrically connected to one terminal of the second terminal row, at least a portion of the fourth circuit pattern is electrically connected to another terminal of the second terminal row via a via formed at the tip, the width of the constricted portion is smaller than the width of the tip when viewed in the thickness direction, and the constricted portion of the FPC is located within the insertion portion. 【0011】 Aspect 6 of the present invention is an imaging module for endoscopes according to any one of aspects 1 to 5, wherein a capacitor is mounted on the first surface or the second surface, and an insulating isolation member is disposed between the capacitor and the first terminal row on the first surface, or between the capacitor and the second terminal row on the second surface. [Effects of the Invention] 【0012】 According to the above embodiment of the present invention, an imaging module for endoscopes can be provided that makes it possible to reduce the diameter of the insertion section of the endoscope by reducing the width of the FPC. [Brief explanation of the drawing] 【0013】 [Figure 1] This is an overall view of the endoscope according to the first embodiment. [Figure 2] This is an overall view of the imaging module according to the first embodiment. [Figure 3] Figure 2 shows the imaging module viewed from the opposite side. [Figure 4](a) is a perspective view of the imaging device of the first embodiment, and (b) is a schematic diagram showing the first electrode group and the second electrode group. [Figure 5] It is a diagram showing a state where an FPC is connected to the imaging device of FIG. 4. [Figure 6] It is a diagram showing a state where an FPC is connected to the imaging device of FIG. 4. [Figure 7] It is a cross-sectional view of FIG. 5. [Figure 8] It is an enlarged view of the tip of the FPC of the first embodiment. [Figure 9] It is a cross-sectional view of the imaging module according to a modification of the first embodiment. [Figure 10] It is an overall view of the imaging module according to the second embodiment. [Figure 11] It is an exploded perspective view of the tip and the constricted portion of the FPC of the second embodiment. 【Embodiments for Carrying Out the Invention】 【0014】 Hereinafter, the endoscope of the present embodiment and the imaging module for the endoscope will be described based on the drawings. (First Embodiment) As shown in FIG. 1, the endoscope 1 includes an insertion portion 2 and an operation portion 3. The insertion portion 2 is inserted into an observation target site of a subject (for example, a human body). The insertion portion 2 has a sheath that houses an imaging module 4 described later. The sheath may be soft or hard. As the soft sheath, a tube made of resin, rubber, or the like can be used. As the hard sheath, a tube made of metal or the like can be used. The operation portion 3 is a part for gripping and operating the endoscope 1. 【0015】 Inside the endoscope 1, an imaging module 4 (imaging module for endoscope) shown in FIG. 2, a relay unit 30, etc. are provided. The imaging module 4 includes an imaging device 10 and an FPC 20 (Flexible Printed Circuit). The FPC 20 electrically connects the imaging device 10 and the relay unit 30. 【0016】 (Definition of Directions) The longitudinal direction of the FPC 20 coincides with the longitudinal direction of the insertion portion 2. In this specification, the longitudinal direction of the FPC 20 may be simply referred to as the "longitudinal direction". In the longitudinal direction, the side where the imaging element 10 is disposed is referred to as the tip side, and the side where the relay unit 30 is disposed is referred to as the base end side. Also, the thickness direction of the FPC 20 may be simply referred to as the "thickness direction". Further, the direction orthogonal to both the longitudinal direction and the thickness direction may be referred to as the "width direction". 【0017】 As shown in FIG. 1, an image cable 3a and a power cable 3b are disposed on the base end side of the operation unit 3. The relay unit 30 is connected to the image cable 3a, the power cable 3b, etc. shown in FIG. 1. The FPC 20 and the relay unit 30 have the role of electrically connecting the imaging element 10 to the image cable 3a, the power cable 3b, etc. 【0018】 As shown in FIGS. 2 and 3, the FPC 20 has a first circuit pattern 27 and a second circuit pattern 28. Although details will be described later, the first circuit pattern 27 is formed on the first surface S1 of the base material 21 included in the FPC 20, and the second circuit pattern 28 is formed on the second surface S2 of the base material 21. Also, a capacitor 26 is mounted on the second surface S2. In FIGS. 2 and 3, illustration of the first coverlay 24 and the second coverlay 25, which will be described later, is omitted. 【0019】 As shown in FIG. 2, the tip portion 20b (the tip - side end portion) of the FPC 20 is connected to the imaging element 10. A connection portion 20a is provided at the base end portion (the base - end - side end portion) of the FPC 20. The connection portion 20a is a portion connected to the relay unit 30. The relay unit 30 has a relay substrate 31 and a connector 32. The connector 32 is a connector for the FPC. In the example of FIG. 2, the base - end - side end portion of the first circuit pattern 27 contacts the terminals in the connector 32, whereby the FPC 20 and the connector 32 are electrically connected. However, the base - end - side end portion of the second circuit pattern 28 may contact the terminals in the connector 32. 【0020】 The FPC 20 has a narrow portion 20c, an intermediate portion 20d, and a wide portion 20e. The narrow portion 20c, the intermediate portion 20d, and the wide portion 20e are arranged in this order from the tip side toward the base end side. The wide portion 20e has a width larger than that of the narrow portion 20c. In this specification, the "width" refers to the dimension in the direction orthogonal to both the thickness direction and the longitudinal direction (i.e., the width direction). In the present embodiment, the width of the narrow portion 20c is constant in the longitudinal direction, and the width of the wide portion 20e is also constant in the longitudinal direction. The width of the intermediate portion 20d increases toward the base end side. However, the widths of the narrow portion 20c and the wide portion 20e may vary in the longitudinal direction. In this case, it is preferable that at least the width of the connecting portion 20a is larger than the maximum width of the narrow portion 20c. 【0021】 The connecting portion 20a is included in the wide portion 20e, and the tip portion 20b is included in the narrow portion 20c. The narrow portion 20c is a portion arranged inside the insertion portion 2 of the endoscope 1 (inside the sheath). In this specification, when viewed from the thickness direction, the width of the imaging element 10 in the direction orthogonal to the longitudinal direction is represented by A. Similarly, the width of the tip portion 20b of the FPC 20 is represented by B, and the width of the wide portion 20e is represented by C. In the present embodiment, A = B. That is, the width of the imaging element 10 is substantially the same as the width of the tip portion 20b of the FPC 20. Therefore, it is possible to avoid the width of the FPC 20 becoming a constraint and the insertion portion 2 becoming thick. However, the width of the tip portion 20b may be smaller than the width of the imaging element 10. In this case as well, it is possible to avoid the dimensions of the FPC 20 becoming a constraint and the insertion portion 2 becoming thick. That is, it is sufficient to satisfy A ≥ B. Since B < C, it is possible to secure the width of the connecting portion 20a while avoiding the insertion portion 2 from becoming thick, and it becomes easier to connect the FPC 20 to the connector 32. 【0022】 As shown in Figure 2, the first circuit pattern 27 includes wirings 27a to 27d. As shown in Figure 3, the second circuit pattern 28 includes wirings 28a to 28b. The role of each wiring can be set as appropriate. The number of wirings included in the first circuit pattern 27 and the number of wirings included in the second circuit pattern 28 may also be changed as appropriate. Some of the wirings 27a to 27d and some of the wirings 28a to 28b may be connected by vias. 【0023】 Figure 4(a) is a perspective view of the image sensor 10 alone, and Figure 4(b) is a schematic diagram showing the first electrode group 13 and the second electrode group 14. As shown in Figure 4(a), the image sensor 10 has a main body 11 and a connecting end face 12. Although not shown, a light-receiving section for photographing a subject is provided at the front end of the main body 11. Inside the main body 11, there is a circuit for generating an electrical signal corresponding to the light received by the light-receiving section. 【0024】 The internal circuits of the main body 11 are electrically connected to the first electrode group 13 and the second electrode group 14 on the connection end face 12. As shown in Figure 4(b), the first electrode group 13 includes two electrodes 13a and 13b, which are arranged side by side with a gap between them in the width direction. Similarly, the second electrode group 14 includes two electrodes 14a and 14b, which are arranged side by side with a gap between them in the width direction. The first electrode group 13 and the second electrode group 14 are spaced apart in the thickness direction. Note that the number of electrodes included in the first electrode group 13 and the second electrode group 14 may be three or more. 【0025】 As shown in Figure 4(a), the connection end face 12 has a first terminal row 121 having two convex portions arranged in a row along the width direction, and a second terminal row 122 having two convex portions arranged in a row along the width direction. The convex portions of the first terminal row 121 include two first connecting conductors 15a and 15b arranged on two electrodes 13a and 13b of the first electrode group 13. The first connecting conductors 15a and 15b constitute the first connecting conductor portion 15. The convex portions of the second terminal row 122 include two second connecting conductors 16a and 16b arranged on two electrodes 14a and 14b of the second electrode group 14. The second connecting conductors 16a and 16b constitute the second connecting conductor portion 16. The convex portions (first connecting conductors 15a, 15b) of the first terminal row 121 are arranged side by side with spacing in the width direction, and the convex portions (second connecting conductors 16a, 16b) of the second terminal row 122 are arranged side by side with spacing in the width direction. The first terminal row 121 and the second terminal row 122 are spaced apart in the thickness direction. Any conductive material can be used for the first connecting conductor portion 15 and the second connecting conductor portion 16. For example, the connecting conductor portions 15 and 16 may be solder balls. 【0026】 During the manufacturing process of the imaging module 4, the tip portion 20b of the FPC 20 is inserted between the first terminal row 121 and the second terminal row 122, which are located on the connection end face 12 of the image sensor 10, and abuts against the connection end face 12. Subsequently, through a reflow process, the first connecting conductors 15a and 15b (ball solder) of the first terminal row 121 are melted and solidified, so that the first connecting conductors 15a and 15b on electrodes 13a and 13b come into contact with the first circuit pattern 27, as shown in Figure 5. This electrically connects the first terminal row 121 to the first circuit pattern 27, ensuring conductivity between the image sensor 10 and the first circuit pattern 27. Similarly, through a reflow process, the second connecting conductors 16a and 16b (ball solder) are melted and solidified, so that the second connecting conductors 16a and 16b on electrodes 14a and 14b come into contact with the second circuit pattern 28, as shown in Figure 6. This electrically connects the second terminal row 122 to the second circuit pattern 28, ensuring conductivity between the image sensor 10 and the second circuit pattern 28. 【0027】 Furthermore, in the reflow process of the manufacturing process of the imaging module 4, solder may be added to electrodes 13a and 13b to increase the amount of connecting conductors, and then the first connecting conductors 15a and 15b on each electrode 13a and 13b may be melted and solidified. This can stabilize the conductivity between the first terminal row 121 and the first circuit pattern 27. Similarly, in the reflow process, solder may be added to electrodes 14a and 14b to increase the amount of connecting conductors, and then the second connecting conductors 16a and 16b on each electrode 14a and 14b may be melted and solidified. This can stabilize the conductivity between the second terminal row 122 and the second circuit pattern 28. 【0028】 Furthermore, during the manufacturing process of the imaging module 4, the leading edge 20b of the FPC 20 may be abutted against the connection end face 12, the FPC may be inserted between the first terminal row 121 and the second terminal row 122, and then a conductive adhesive may be applied between the first terminal row 121 and the first circuit pattern 27 and cured. The conductive adhesive electrically connects the first terminal row 121 to the first circuit pattern 27, ensuring conductivity between the image sensor 10 and the first circuit pattern 27. Similarly, a conductive adhesive may be applied between the second terminal row 122 and the second circuit pattern 28 and cured. The conductive adhesive electrically connects the second terminal row 122 to the second circuit pattern 28, ensuring conductivity between the image sensor 10 and the second circuit pattern 28. 【0029】 In the example in Figure 5, the first connecting conductor 15a electrically connects electrode 13a and the first circuit pattern 27. The first connecting conductor 15b electrically connects electrode 13b and the first circuit pattern 27. In the example in Figure 6, the second connecting conductor 16a electrically connects electrode 14a and the second circuit pattern 28. The second connecting conductor 16b electrically connects electrode 14b and the second circuit pattern 28. In addition, during the manufacturing process of the imaging module 4, after the tip 20b of the FPC 20 is abutted against the connecting end face 12, the first connecting conductors 15a and 15b may be placed on each electrode of the first electrode group 13, and the second connecting conductors 16a and 16b may be placed on each electrode of the second electrode group 14. As shown in the examples in Figures 5 and 6, in an imaging module 4 in which the first terminal row 121 is electrically connected to the first circuit pattern 27 and the second terminal row 122 is electrically connected to the second circuit pattern 28, it is sufficient that the end of the FPC 20 is inserted (interposed) between the first terminal row 121 and the second terminal row 122. 【0030】 Figure 7 is a cross-sectional view of the image sensor 10 and FPC 20 shown in Figure 5, along the thickness and longitudinal directions. Although not shown in Figures 5 and 6, after connecting the FPC 20 to the image sensor 10, a sealing resin R as shown in Figure 7 may be provided. By providing the sealing resin R, the connection portion between the image sensor 10 and the FPC 20 can be protected and reinforced. 【0031】 As shown in Figure 7, the FPC 20 includes a base material 21, a first conductor layer 22, a second conductor layer 23, a first coverlay 24, and a second coverlay 25. The "thickness direction" is also the direction in which each layer of the FPC 20 is stacked. The first conductor layer 22 constitutes a first circuit pattern 27, and the second conductor layer 23 constitutes a second circuit pattern 28. The first conductor layer 22 and the second conductor layer 23 are formed of, for example, copper. The base material 21 includes a shield layer 21a, a first insulating layer 21b, and a second insulating layer 21c. The first conductor layer 22 is formed on the first insulating layer 21b. The second conductor layer 23 is formed on the second insulating layer 21c. That is, the surface of the first insulating layer 21b is the first surface S1 on which the first circuit pattern 27 is formed, and the surface of the second insulating layer 21c is the second surface S2 on which the second circuit pattern 28 is formed. 【0032】 Each electrode 13a, 13b, 14a, and 14b of the image sensor 10 functions, for example, as a power terminal, a GND (ground) terminal, a clock signal terminal, and a video signal terminal, respectively. The function assignment to each electrode 13a, 13b, 14a, and 14b can be changed as appropriate. However, the presence of the shield layer 21a suppresses crosstalk between the first circuit pattern 27 and the second circuit pattern 28. For this reason, for example, one of the first terminal row 121 (first electrode group 13) and the second terminal row 122 (second electrode group 14) may include a clock signal terminal and the other may include a power terminal. In this case, the shield layer 21a can suppress noise emitted by the wiring connected to the clock signal terminal from affecting the wiring connected to the power terminal. Alternatively, one of the first terminal row 121 (first electrode group 13) and the second terminal row 122 (second electrode group 14) may include a clock signal terminal and the other may include a video signal terminal. In this case, the shield layer 21a can suppress the noise emitted by the wiring connected to the clock signal terminal from affecting the wiring connected to the video signal terminal. 【0033】 The leading edge 20b of the FPC 20 does not have a first coverlay 24, and the first conductor layer 22 (i.e., the first circuit pattern 27) is exposed. Similarly, the leading edge 20b does not have a second coverlay 25, and the second conductor layer 23 (i.e., the second circuit pattern 28) is exposed. This allows the first circuit pattern 27 to be electrically connected to the first terminal row 121, and the second circuit pattern 28 to the second terminal row 122. In addition, in the longitudinal direction, in the portion located between the capacitor 26 and the second connecting conductors 16a and 16b, an isolation member 25a is provided on the second conductor layer 23. The isolation member 25a prevents the liquefied second connecting conductors 16a and 16b from flowing toward the capacitor 26 when, for example, the second connecting conductors 16a and 16b are formed by reflow soldering. Therefore, it is possible to prevent an improper short circuit between the second terminal row 122 and the capacitor 26. In this embodiment, the isolation member 25a is part of the second coverlay 25. However, the isolation member 25a only needs to have insulating properties and does not need to be part of the second coverlay 25. 【0034】 As shown in Figure 7, the first connecting conductors 15a and 15b of the first terminal row 121 are melted and solidified through the reflow process, making contact with the electrodes of the first electrode group 13 and the first conductor layer 22, respectively. That is, the first terminal row 121 and the first conductor layer 22 are electrically connected, ensuring conductivity between the image sensor 10 and the first circuit pattern 27. Similarly, the second connecting conductors 16a and 16b of the second terminal row 122 are in contact with the electrodes of the second electrode group 14 and the second conductor layer 23, respectively. That is, the second terminal row 122 and the second conductor layer 23 are electrically connected, ensuring conductivity between the image sensor 10 and the second circuit pattern 28. 【0035】 Here, during the manufacturing process of the imaging module 4, when inserting the tip portion 20b of the FPC 20 between the first terminal row 121 and the second terminal row 122, if the first conductor layer 22 (first circuit pattern 27) and the first connecting conductors 15a and 15b of the first terminal row 121 come into contact, the tip portion 20b may not properly abut against the connecting end face 12. Therefore, as shown in Figure 8, the tip end of the first circuit pattern 27 may be offset toward the side away from the image sensor 10 (the base end side). More specifically, a gap D may be provided between the edge E1 of the base material 21 on the tip side and the edge E2 of the first circuit pattern 27 on the tip side. By providing such a gap D, the edge E1 of the base material 21 and the edge E2 of the first circuit pattern 27 are positioned apart, which can prevent interference between the first terminal row 121 and the first circuit pattern 27 and cause abutting failure when the leading edge 20b of the FPC 20 abuts against the connection end face 12. Although not shown in the figures, a gap may also be provided between the edge E1 of the base material 21 and the edge of the second circuit pattern 28, so that the edge E1 of the base material 21 and the edge of the second circuit pattern 28 are positioned apart. 【0036】 Furthermore, the first connecting conductors 15a and 15b, each positioned on an electrode in the first electrode group 13, may be electrically connected to the first conductor layer 22 (first circuit pattern 27) via a conductive adhesive 17. Similarly, the second connecting conductors 16a and 16b, each positioned on an electrode in the second electrode group 14, may be electrically connected to the second conductor layer 23 (second circuit pattern 28) via a conductive adhesive 17. Figure 9 shows a modified example of the imaging module 4 of this embodiment shown in Figure 7. In the imaging module 4' shown in Figure 9, the first connecting conductors 15a and 15b of the first terminal row 121 and the first conductor layer 22 are separated in the thickness direction, but conductivity between the first terminal row 121 and the first conductor layer 22 is ensured by the interposition of the conductive adhesive 17. Similarly, although the second connecting conductors 16a and 16b of the second terminal row 122 and the second conductor layer 23 are separated in the thickness direction, the conductive adhesive 17 interposes the second terminal row 122 and the second conductor layer 23, ensuring electrical conductivity between them. As shown in Figure 9, in the imaging module 4', the leading edge of the first conductor layer 22 and the second conductor layer 23 extends to the leading edge of the substrate 21. Thus, the gap D (see Figure 8) may not be necessary. 【0037】 As described above, the imaging module 4 of this embodiment is located inside the endoscope 1 having the insertion section 2. The imaging module 4 comprises an image sensor 10 having a connection end face 12, a first terminal row 121 and a second terminal row 122 formed on the connection end face 12, a substrate 21 having a first surface S1 and a second surface S2, and an FPC 20 having a first circuit pattern 27 formed on the first surface S1 and a second circuit pattern 28 formed on the second surface S2. The tip portion 20b of the FPC 20 is inserted between the first terminal row 121 and the second terminal row 122, at least a portion of the first circuit pattern 27 is electrically connected to the first terminal row 121, and at least a portion of the second circuit pattern 28 is electrically connected to the second terminal row 122. When viewed from the thickness direction of the FPC 20, if the width of the connection end face 12 is A and the width of the tip portion 20b of the FPC 20 is B, then A ≥ B is satisfied, and the tip portion 20b of the FPC 20 is positioned within the insertion portion 2. 【0038】 With this configuration, since circuit patterns 27 and 28 are formed on both sides of the FPC 20, it is possible to reduce the width of the FPC 20 compared to the case where the circuit pattern is formed on only one side of the FPC 20. In addition, since the width B of the tip portion 20b of the FPC 20 is less than or equal to the width A of the connection end face 12, it is possible to avoid the FPC 20 causing an increase in the diameter of the insertion portion 2. This contributes to reducing the diameter of the insertion portion 2. 【0039】 Furthermore, the FPC 20 has a narrow portion 20c including a tip portion 20b and a wide portion 20e. When viewed from the thickness direction, the width of at least a part of the wide portion 20e is greater than the width of the tip portion 20b, and a connecting portion 20a for connection to the connector 32 is provided on the wide portion 20e. By arranging the narrow portion 20c within the insertion portion 2 and arranging the wide portion 20e closer to the base end than the insertion portion 2, it is possible to avoid making the insertion portion 2 thicker while securing the width of the connecting portion 20a and facilitating connection between the FPC 20 and the connector 32. 【0040】 Furthermore, the substrate 21 includes a conductive shield layer 21a and a first insulating layer 21b and a second insulating layer 21c, respectively, arranged on both sides of the shield layer 21a. The surface of the first insulating layer 21b is the first surface S1, and the surface of the second insulating layer 21c is the second surface S2. With this configuration, it is possible to suppress crosstalk between the first circuit pattern 27 formed on the first surface S1 and the second circuit pattern 28 formed on the second surface S2 by the shield layer 21a. The shield layer 21a may be a so-called solid pattern or a mesh. Furthermore, in this case, one of the first terminal row 121 and the second terminal row 122 may include video signal terminals, and the other may include clock signal terminals. With this configuration, since the substrate 21 having a shielding layer 21a is placed between the first terminal row 121 and the second terminal row 122, the shielding layer 21a can suppress crosstalk from the clock signal to the video signal. 【0041】 Furthermore, viewed from the thickness direction, the edge E1 on the image sensor 10 side of the first insulating layer 21b and the edge E2 on the image sensor 10 side of the first circuit pattern 27 are spaced apart. That is, a gap D is provided as shown in Figure 8. This suppresses interference between the first terminal row 121 and the first circuit pattern 27 when inserting the FPC 20 between the first terminal row 121 and the second terminal row 122. Therefore, the phenomenon in which the leading edge 20b of the FPC 20 cannot properly abut against the connection end face 12 can be avoided. Similarly, although not shown in the figure, the edge on the image sensor 10 side of the second insulating layer 21c and the edge on the image sensor 10 side of the second circuit pattern 28 may also be spaced apart when viewed from the thickness direction. 【0042】 Furthermore, in this embodiment, the imaging module 4 has a capacitor 26 mounted on the second surface S2, and an insulating isolation member 25a is placed between the capacitor 26 and the second connecting conductors 16a and 16b on the second surface S2. Therefore, when the second connecting conductors 16a and 16b are formed by solder or the like, the solder or the like can flow toward the capacitor 26, which can prevent the occurrence of an inappropriate short circuit. 【0043】 (Second Embodiment) Next, a second embodiment of the present invention will be described, which has the same basic configuration as the first embodiment. For this reason, the same reference numerals are used for similar components, and their descriptions are omitted; only the differences will be described. 【0044】 As shown in Figure 9, the imaging module 4 of this embodiment comprises an image sensor 10 and an FPC 33. The FPC 33 electrically connects the image sensor 10 to a relay unit (not shown). The FPC 33 has a tip portion 20b (the end on the tip side) connected to the image sensor 10 and a constricted portion 20f located on the opposite side of the tip portion 20b from the image sensor 10. That is, in the FPC 33, the tip portion 20b, the constricted portion 20f, the intermediate portion 20d, and the wide portion 20e are arranged in order from the tip side to the base end side. As will be described later, the FPC 33 of this embodiment has a base material 34 (see Figure 10), and this base material 34 has multiple layers, and the stacking direction of these multiple layers is called the thickness direction of the FPC 33. The direction perpendicular to both the longitudinal direction and the thickness direction of the FPC 33 is called the width direction. 【0045】 Viewed from the thickness direction of the FPC33, the width F (dimension in the width direction, hereafter the same) of the constricted portion 20f is smaller than the width B of the tip portion 20b. In other words, viewed from the thickness direction, the maximum width of the constricted portion 20f is smaller than the maximum width of the tip portion 20b. The width of the tip portion 20b is less than or equal to the width A of the image sensor 10. The constricted portion 20f, together with the tip portion 20b, is located within the insertion portion 2 of the endoscope 1 (see Figure 1). 【0046】 As shown in Figures 9 and 10, the FPC 33 has a base material 34, which has a structure in which an outer first layer 34a, an inner first layer 34b, an inner second layer 34c, and an outer second layer 34d are laminated in order. That is, the base material 34 at the tip portion 20b and the constricted portion 20f has these multiple layers 34a to 34d. Each of the multiple layers may be composed of an insulating layer or a shielding layer. The first surface S1 of the base material 34 is the surface of the outer first layer 34a, and the second surface S2 of the base material 34 is the surface of the outer second layer 34d. 【0047】 The FPC 33 has a first circuit pattern 27, a second circuit pattern 28, a third circuit pattern 35, and a fourth circuit pattern 36. The first circuit pattern 27 is formed on the first surface S1 of the substrate 34, and the second circuit pattern 28 is formed on the second surface S2 of the substrate 34. The third circuit pattern 35 is formed on the inner first layer 34b, and the fourth circuit pattern 36 is formed on the inner second layer 34c. That is, the circuit patterns 27, 28, 35, and 36 are each arranged on different layers from among the multiple layers 34a to 34d. Although coverlays are provided on the first surface S1 and the second surface S2 so as to cover the first circuit pattern 27 and the second circuit pattern 28, these coverlays are not shown in the illustration. At least an insulating layer is provided between adjacent circuit patterns, and from the viewpoint of preventing crosstalk, a configuration in which a shield layer is sandwiched between two insulating layers may be provided between adjacent circuit patterns. 【0048】 The first circuit pattern 27 includes wirings 27e to 27i. Wiring 27e extends from its tip 20b, through the constricted portion 20f and the intermediate portion 20d, to the connection portion 20a of the wide portion 20e. That is, wiring 27e can electrically connect the image sensor 10 and the relay unit. Wirings 27f to 27h are located in the wide portion 20e, with a portion of each wiring located at the connection portion 20a. Wiring 27i is located in the tip 20b. The tip of wiring 27e and wiring 27i are not covered by the coverlay. 【0049】 The third circuit pattern 35 includes wiring 35a. Wiring 35a extends from its tip 20b, through the constricted portion 20f and the intermediate portion 20d, to the wider portion 20e. The tip of wiring 35a is electrically connected to wiring 27i of the first circuit pattern 27 via via 37. Via 37 is made of a conductor formed by metal plating or the like on the inner surface of a through-hole formed through the outer first layer 34a and the inner first layer 34b. Wiring 35a in the wider portion 20e is connected to the first circuit pattern 27 by vias or the like (not shown). It is electrically connected to wiring 27f. That is, wiring 27i, wiring 35a, and wiring 27f can electrically connect the image sensor 10 and the relay unit. Note that the third circuit pattern 35 may include other wiring that does not contribute to the electrical connection between the image sensor 10 and the relay unit. 【0050】 The second circuit pattern 28 includes wirings 28c and 28d. Wiring 28c extends from the tip portion 20b, through the constricted portion 20f and the intermediate portion 20d, to the wide portion 20e. Wiring 28c in the wide portion 20e is electrically connected to wiring 27h of the first circuit pattern 27 by vias or the like (not shown). That is, wirings 28c and 27h can electrically connect the image sensor 10 and the relay unit. Wiring 28d is located at the tip portion 20b. The tip portion of wiring 28c and wiring 28d are not covered by the coverlay. 【0051】 The fourth circuit pattern 36 includes wiring 36a. Wiring 36a extends from its tip 20b, through the constricted portion 20f and the intermediate portion 20d, to the wide portion 20e. The tip of wiring 36a is electrically connected to wiring 28d of the second circuit pattern 28 via via 38. Via 38 is made of a conductor formed by metal plating or the like on the inner surface of a through-hole formed through the inner second layer 34c and the outer second layer 34d. Wiring 36a in the wide portion 20e is electrically connected to wiring 27g of the first circuit pattern 27 by vias or the like (not shown). That is, wiring 28d, wiring 36a, and wiring 27g can electrically connect the image sensor 10 and the relay unit. Note that the fourth circuit pattern 36 may include other wiring that does not contribute to the electrical connection between the image sensor 10 and the relay unit. 【0052】 Although not shown, the tip of wiring 27e and wiring 27i in the first circuit pattern 27 are electrically connected to electrodes 13b (one terminal) and 13a (the other terminal) of the first terminal row 121 (see Figure 4) by solder or conductive adhesive, respectively. Therefore, wiring 27e electrically connects the image sensor 10 to the relay unit, and wirings 27i, 35a, and 27f electrically connect the image sensor 10 to the relay unit. Also, although not shown, the tip of wiring 28c and wiring 28d in the second circuit pattern 28 are electrically connected to electrodes 14b (one terminal) and 14a (the other terminal) of the second terminal row 122 (see Figure 4) by solder or conductive adhesive, respectively. Therefore, wirings 28c and 27h electrically connect the image sensor 10 to the relay unit, and wirings 28d, 36a, and 27g electrically connect the image sensor 10 to the relay unit. 【0053】 As described above, the imaging module 4 of this embodiment has an FPC 33 which has a constricted portion 20f located on the opposite side of the tip portion 20b from the image sensor 10, the substrate 34 in the tip portion 20b and the constricted portion 20f has a plurality of layers 34a to 34d, the FPC 33 has a third circuit pattern 35 and a fourth circuit pattern 36 located in different layers 34b and 34c of the plurality of layers 34a to 34d, at least a portion of the first circuit pattern 27 is electrically connected to one electrode 13b (one terminal) of the first terminal row 121, and at least a portion of the third circuit pattern 35 The tip portion 20b is electrically connected to another electrode 13a (another terminal) of the first terminal row 121 via a via 37 formed on the tip portion 20b, at least a portion of the second circuit pattern 28 is electrically connected to one electrode 14b (one terminal) of the second terminal row 122, and at least a portion of the fourth circuit pattern 36 is electrically connected to another electrode 14a (another terminal) of the second terminal row 122 via a via 38 formed on the tip portion 20b, and the width of the constricted portion 20f is smaller than the width of the tip portion 20b when viewed in the thickness direction, and the constricted portion 20f of the FPC 33 is located inside the insertion portion 2. 【0054】 With this configuration, at the tip portion 20b of the FPC 33, multiple wirings are arranged side by side in the width direction, while at the constricted portion 20f, they are arranged in different layers among multiple layers, allowing the multiple wirings to be positioned so that they overlap when viewed from the thickness direction. Therefore, the width of the constricted portion 20f can be made smaller than the width of the tip portion 20b. Thus, the portion of the insertion portion 2 of the endoscope 1 corresponding to the constricted portion 20f can be made even thinner. Furthermore, when multiple wirings in an FPC are arranged side by side in the width direction, the width dimension becomes larger than the thickness of the FPC, making it easy to bend the FPC around an axis extending in the width direction, but it can be difficult to bend the FPC around an axis extending in the thickness direction. However, with the configuration in this embodiment, by making the width of the constricted portion 20f even smaller, the difference between the thickness and width at the constricted portion 20f can be further reduced. In addition, the FPC 33 placed inside the insertion portion 2 of the endoscope 1 is bent at the constricted portion 20f. Therefore, the difference in bendability between the axis extending in the width direction and the axis extending in the thickness direction of the FPC33 can be reduced. 【0055】 The technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. 【0056】 For example, the capacitor 26 may be mounted on the first surface S1 instead of the second surface S2. Furthermore, an insulating isolation member may be placed between the capacitor 26 and the first connecting conductors 15a and 15b on the first surface S1. Alternatively, the capacitor 26 may be mounted on both the first surface S1 and the second surface S2. Furthermore, an insulating isolation member may be placed between the capacitor 26 and the first connecting conductors 15a and 15b on the first surface S1, and between the capacitor 26 and the second connecting conductors 16a and 16b on the second surface S2. Alternatively, the capacitor 26 may not be mounted on either the first surface S1 or the second surface S2. 【0057】 Furthermore, without departing from the spirit of the present invention, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments and modifications may be combined as appropriate. [Explanation of symbols] 【0058】 1…Endoscope 2…Insertion section 4, 4'…Imaging module 10…Image sensor 12…Connection end face 121…First terminal row 122…Second terminal row 13…First electrode group 14…Second electrode group 15a, 15b…First connecting conductor 16a, 16b…Second connecting conductor 20…FPC 20a…Connection section 20b…Tip section 20c…Narrow section 20e…Wide section 21…Base material 21a…Shielding layer 21b…First insulating layer 21c…Second insulating layer 25a…Isolation member 26…Capacitor 27…First circuit pattern 28…Second circuit pattern 32…Connector S1…First surface S2…Second surface

Claims

[Claim 1] An endoscopic imaging module that is placed inside an endoscope having an insertion section, An image sensor having a connecting end face, The first and second terminal rows formed on the connecting end face, The FPC comprises a substrate having a first surface and a second surface, a first circuit pattern formed on the first surface, and a second circuit pattern formed on the second surface. The tip of the FPC is inserted between the first terminal row and the second terminal row. At least a portion of the first circuit pattern is electrically connected to the first terminal row, At least a portion of the second circuit pattern is electrically connected to the second terminal row, When viewed from the thickness direction of the FPC, if the width of the connecting end face is A and the width of the tip portion of the FPC is B, then A ≥ B satisfies, The tip portion of the FPC is positioned within the insertion portion. The FPC has a constricted portion located on the opposite side of the tip from the image sensor, The base material in the tip portion and the constricted portion has multiple layers, The FPC has a third circuit pattern and a fourth circuit pattern arranged in different layers among the plurality of layers, At least a portion of the first circuit pattern is electrically connected to one terminal of the first terminal row, and at least a portion of the third circuit pattern is electrically connected to another terminal of the first terminal row via a via formed at the tip. At least a portion of the second circuit pattern is electrically connected to one terminal of the second terminal row, and at least a portion of the fourth circuit pattern is electrically connected to another terminal of the second terminal row via a via formed at the tip. Viewed from the thickness direction, the width of the constricted portion is smaller than the width of the tip portion. The constricted portion of the FPC is an imaging module for endoscopes, which is positioned within the insertion portion. [Claim 2] The FPC has a narrow portion including the tip portion and a wide portion, Viewed from the thickness direction, the width of at least a portion of the wide portion is greater than the width of the tip portion. The endoscope imaging module according to claim 1, wherein the wide portion is provided with a connection portion that connects to a connector. [Claim 3] The substrate comprises a conductive shielding layer and a first insulating layer and a second insulating layer disposed on both sides of the shielding layer, respectively. The first surface is the surface of the first insulating layer, The endoscope imaging module according to claim 1, wherein the second surface is the surface of the second insulating layer. [Claim 4] The imaging module for endoscopes according to claim 1, wherein one of the first and second terminal rows includes a video signal terminal and the other includes a clock signal terminal. [Claim 5] A capacitor is mounted on the first or second surface. An endoscope imaging module according to any one of claims 1 to 4, wherein an insulating isolation member is disposed between the capacitor and the first terminal row on the first surface, or between the capacitor and the second terminal row on the second surface.

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