JP2013123628A - Imaging unit for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging unit for an endoscope, wherein a flexible board mounted with an imaging element is bent, wherein the peeling or the like of a terminal part of the imaging element from the flexible board does not occur, and which has a good heat radiation property.SOLUTION: This imaging unit 100 for the endoscope includes: the flexible board 11 having a mounting part mounted with the imaging element 1, mounting parts mounted with peripheral electronic components 15 except the imaging element, and bending parts formed between two mounting parts; and a support member 21 having heat conductivity conducting heat generated from the imaging element 1, and supporting the flexible board 11. The support member 21 has: at least one end part positioning bending starting points in the bending parts of the flexible board 11; and an abutment part 21B abutting on the mounting parts mounted with the peripheral electronic components 15 to prevent the excess bending of the flexible board 11.

Description

  The present invention relates to an endoscope imaging unit, and more particularly to an endoscope imaging unit having an imaging element mounted on a flexible substrate.

  Conventionally, endoscopes have been widely used in the medical field and the industrial field. The subject is imaged by an image sensor provided at the distal end portion of the insertion portion of the endoscope, and the subject image is displayed on the monitor device. The surgeon or the like can observe and observe the subject image displayed on the monitor.

  In the case of an endoscope, in order to reduce the size of the imaging unit, the imaging element provided in the distal end portion of the insertion portion is a so-called bare-chip imaging element and is mounted on a flexible substrate. The electrical connection method between the image pickup device and the flexible substrate is a method of connecting a plurality of terminal portions extending from the side surface and a plurality of land portions of the flexible substrate on the side surface of the chip of the image pickup device. There is also a method of connecting a plurality of through electrodes on the back surface of the chip of the image sensor and a plurality of lands of the flexible substrate.

  Since the outer diameter of the insertion portion of the endoscope is small, an endoscope imaging unit is configured by bending a flexible substrate on which a bare chip imaging device is mounted and storing it in the distal end portion of the insertion portion (for example, a patent Reference 1).

JP 2010-258582 A

  However, when manufacturing such an imaging unit, the flexible substrate is distorted when the flexible substrate on which the imaging device is mounted is bent, and the terminal portion of the imaging device is peeled off from the flexible substrate, or the connection between the imaging device and the flexible substrate is performed. There is a risk of damage to the part. Generation | occurrence | production of such a peeling from the flexible substrate of the terminal part of an image pick-up element reduces the connection reliability of an image pick-up element and a flexible substrate.

  For example, connecting a plurality of through electrodes which are terminal portions on the back surface of the chip of the image sensor and a plurality of lands of the flexible substrate and bending the flexible substrate near the side surface of the image sensor means that the terminal portion of the image sensor is flexible. There is a risk of peeling from the substrate.

  Furthermore, the image pickup device mounted on the insertion portion of the small-diameter endoscope has been increased in pixel count, the image pickup device has come to incorporate a logic circuit that performs digital processing, and so on. Accordingly, in order to suppress the occurrence of image noise due to the temperature rise of the imaging unit, the imaging unit for endoscope must have better heat dissipation.

  Accordingly, the present invention provides an endoscope that has an excellent heat dissipation property in an imaging unit configured by bending a flexible substrate on which an imaging device is mounted, without causing peeling of the terminal portion of the imaging device from the flexible substrate. An object of the present invention is to provide an image pickup unit for use.

  According to one aspect of the present invention, at least a first mounting portion having a first mounting surface for mounting an image sensor that is a first electronic component, and a second electronic component that is an electronic component other than the image sensor. A flexible board having a second mounting portion having a second mounting surface for mounting the first mounting portion and a bent portion provided between the first mounting portion and the second mounting portion; A support member that is provided on the back side of the first mounting surface of the mounting portion and has heat conductivity for conducting heat emitted from the imaging device and supports the flexible substrate, and the support member Is an internal view having at least one end portion for positioning a bending start point in the bent portion of the flexible substrate, and an abutting portion that prevents the flexible substrate from being bent excessively by contacting the second mounting portion. Mirror shooting It is possible to provide a unit.

  According to the present invention, in an imaging unit configured by bending a flexible substrate on which an imaging element is mounted, an endoscope having good heat dissipation without causing peeling of a terminal portion of the imaging element from the flexible substrate. Image pickup unit can be realized.

It is a top view which shows the 1st surface of the flexible substrate with which the image pick-up element is mounted concerning embodiment of this invention. It is a bottom view which shows the 2nd surface used as the back surface of the 1st surface of the flexible substrate with which the image pick-up element is mounted concerning embodiment of this invention. It is a front view of the flexible substrate 11 concerning embodiment of this invention. It is a front view of the flexible substrate 11 when the supporting member 21 is provided in the back side 11B of the flexible substrate 11 concerning embodiment of this invention. It is a perspective view of the supporting member 21 concerning embodiment of this invention. It is a front view of the flexible substrate 11 with which the image pick-up element 1 was mounted concerning embodiment of this invention. It is a front view of the imaging unit which shows the state which bent the flexible substrate 11 concerning embodiment of this invention. It is a front view of the imaging unit which shows the state with which it filled with the filler 26 in the state which bent the flexible substrate 11 concerning embodiment of this invention. It is a figure for demonstrating the case where the image pick-up element 1 is mounted in the flexible substrate 11, after bending a flexible substrate based on the modification 1 of embodiment of this invention. It is a front view of the imaging unit which has the supporting member 21 to which the cable 33 for thermal radiation was soldered based on the modification 2 of embodiment of this invention. It is a perspective view of the supporting member 21a which concerns on the modification 3 of embodiment of this invention. It is a front view of the imaging unit which concerns on the modification 4 of embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
In each drawing used for the following explanation, in order to make each constituent element large enough to be recognized on the drawing, there are some constituent elements that have different scales. It is not limited only to the quantity of the component described in the drawing, the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.
(Configuration of flexible substrate)
FIG. 1 is a plan view showing a first surface of a flexible substrate on which an image sensor is mounted according to the present embodiment. FIG. 2 is a bottom view showing a second surface that is the back surface of the first surface of the flexible substrate on which the imaging element is mounted according to the present embodiment. FIG. 3 is a front view of the flexible substrate 11. As shown in FIGS. 1 and 2, the flexible substrate 11 constituting the imaging unit is a rectangular substrate having a length L1 and a width L2. In FIG. 3, the image pickup device 1 mounted on the flexible substrate 11 is indicated by a one-dot chain line. For example, the length L1 is 10 mm and the length L2 is 2 mm.

The flexible substrate 11 is provided with a plurality of land electrodes (hereinafter referred to as lands) for electrical connection with elements to be mounted and the outside.
As shown in FIGS. 1 and 3, a first surface (hereinafter referred to as “surface”) 11 </ b> A of the flexible substrate 11 has a plurality of components for establishing electrical continuity when the imaging device 1 as an electronic component is mounted. (In this case, 16) image sensor lands 12 are formed. The surface 11A is an area including the image sensor land 12 and has an image sensor mounting surface 17 on which the image sensor 1 is mounted.
In a region near both ends of the surface 11A, a plurality of external lands 13 are formed for electrical continuity with the outside. A part or all of the plurality of external lands 13 may be provided on the back surface 11B.

The image sensor 1 mounted on the image sensor mounting surface 17 of the surface 11A is, for example, a CMOS image sensor. On the back surface of the image pickup surface of the image pickup device 1, a plurality of (here, 16) image pickup device lands 2, which are terminal portions made of BGA (Ball Grid Array) or LGA (Land Grid Array) provided in the through electrode portion. Is formed. The image sensor land 2 of the image sensor 1 is electrically connected to the corresponding image sensor land 12 on the flexible substrate 11 via, for example, a solder member. A cover glass 3 is provided on the imaging surface side of the imaging element 1.
The flexible substrate 11 has a multilayer structure, and lands including the image sensor land 12 and the external land 13 are electrically connected by a plurality of wiring patterns 14 formed in the multilayer structure.

As shown in FIG. 2, the second surface (hereinafter referred to as the back surface) 11B of the flexible substrate 11 has a peripheral electronic component mounting surface 19 on which one or a plurality of peripheral electronic components 15 other than the image sensor are mounted. And the part of the image pick-up element mounting surface 17 of the flexible substrate 11 comprises the image pick-up element mounting part 18 irrespective of the surface 11A and the back surface 11B.
In the present embodiment, the image sensor mounting portion 18 is provided at substantially the center of the surface 11A of the flexible substrate 11. However, the present invention is not limited to this and may be provided at a position deviated from the center of the surface 11A.
The peripheral electronic component 15 is a capacitor, for example. The peripheral electronic component mounting surface 19 is disposed in a region other than the image sensor mounting portion 18 on the back surface 11B. In the present embodiment, the two regions of the back surface 11 </ b> B that are separated from the image sensor mounting portion 18 provided in the central portion of the flexible substrate 11 are the peripheral electronic component mounting surface 19. The peripheral electronic component mounting surface 19 of the flexible substrate 11 constitutes the peripheral electronic component mounting portion 20 regardless of the front surface 11A or the back surface 11B.

  The imaging element mounting portion 18 on the back surface 11B is a support member bonding region 16 to which a support member 21 (see FIG. 4) described later is bonded. As described later, the flexible substrate 11 is orthogonal to the longitudinal direction of the flexible substrate 11. And bent along the side 16 a of the support member bonding region 16. A region outside the side 16a constitutes a bent portion 16b provided between the mounting portion on which the imaging element 1 is mounted and the mounting portion on which the plurality of peripheral electronic components 15 are mounted. In the present embodiment, as shown in FIG. 2, the two regions outside the two sides 16 a of the support member bonding region 16 constitute a bent portion 16 b.

  As described above, the flexible substrate 11 includes the image sensor mounting portion 18 having the image sensor mounting surface 17 on which the image sensor 1 that is at least one electronic component is mounted, and the peripheral electronic component 15 that is an electronic component other than the image sensor 1. The peripheral electronic component mounting portion 20 having the peripheral electronic component mounting surface 19 for mounting the mounting portion and the bent portion 16b provided between the two mounting portions.

The imaging device 1 is mounted on the front surface 11A of the flexible substrate 11, and the flexible substrate 11 is bent toward the back surface 11B side at the two bent portions 16b and disposed in the distal end portion of the endoscope. As will be described later, when the flexible substrate 11 is bent to the back surface 11B side, the flexible substrate 11 is distorted, and each image sensor land 12 on the flexible substrate 11 and each image sensor land 2 of the image sensor 1 are flexible. The support member 21 is provided on the back surface 11B of the flexible substrate 11 so as not to be peeled off from the connection portion with the substrate 11 or to be damaged.
Note that the front surface 11A and the back surface 11B of the flexible substrate 11 are covered with an insulating resist in areas other than the land including the image sensor land 12 and the external land 13.
(Configuration of support member)
FIG. 4 is a front view of the flexible substrate 11 when the support member 21 is provided on the back side 11 </ b> B of the flexible substrate 11. FIG. 5 is a perspective view of the support member 21.
As shown in FIG. 5, the support member 21 includes an adhesive portion 21 </ b> A that is bonded to the back surface 11 </ b> B of the flexible substrate 11 with an adhesive 22, and a contact portion 21 </ b> B that the back surface 11 </ b> B contacts when the flexible substrate 11 is bent. The connecting portion 21C connects the bonding portion 21A and the contact portion 21B. The contact portion 21 </ b> B is also an abutting portion that prevents the flexible substrate 11 from being bent excessively when the flexible substrate 11 is bent. As the adhesive 22, for example, a thermosetting material such as an epoxy resin, an adhesive for die bonding including an epoxy resin, or the like is used.
Further, the support member 21 is made of a metal, ceramic, or the like with high thermal conductivity. This is because, in the case of an image sensor in which a logic circuit is provided in the periphery of the image sensor, such as a CMOS sensor, the heat generation amount is large, but the thermal conductivity of the cover glass provided on the image pickup surface side of the image sensor 1 is low. By configuring the support member 21 with a member having high thermal conductivity, even in such a case, the support member 21 absorbs heat from the imaging unit region of the image sensor and dissipates heat from the other parts of the support member 21. This is to reduce noise in an image obtained by the image sensor.

  As described above, the support member 21 is provided on the back side of the image pickup device mounting surface 17 of the image pickup device mounting portion 18 of the image pickup device 1 and has thermal conductivity for conducting heat generated from the image pickup device 1. 11 is a member that supports 11.

The bonding portion 21A has a flat flexible substrate bonding surface 23 to which the flexible substrate 11 is bonded. That is, the support member 21 has a flat surface that supports the flexible substrate 11 in the bonding portion 21A. The shape of the flexible substrate bonding surface 23 is a rectangle, one side of the rectangle is substantially the same length as the width L2 of the flexible substrate 11, and the plurality of image sensor lands 2 of the image sensor 1 are provided on the other side. The length L3 is larger than the width of the region. An adhesive 22 is applied to the support member bonding region 16 indicated by the oblique lines in FIG. 2 of the flexible substrate 11, and the flexible substrate bonding surface 23 of the bonding portion 21 </ b> A is in close contact with and bonded to the support member bonding region 16. The lengths L2 and L3 are, for example, about 2 mm, and the distance between the image sensor lands 12 and the external lands 13 is, for example, 0.4 mm.
In the present embodiment, the flexible substrate bonding surface 23 of the support member 21 is fixed to the support member bonding region 16 of the flexible substrate 11 by the adhesive 22. As long as the support member 21 can be fixed to the flexible substrate 11 by providing a land for fixing the support member 21 to the support member 21 and fixing the flexible substrate bonding surface 23 of the support member 21 to the support member bonding region 16 by soldering, any means can be used. Absent.

  The support member 21 is configured such that a cross-sectional shape when cut in a direction perpendicular to the flexible substrate bonding surface 23 has an H shape along the length L3 direction. Therefore, the support member 21 has an H shape when the support member 21 is viewed along the length L2 direction. That is, as shown in FIG. 5, the shape of the side surface 25 of the support member 21 is an H shape.

  As will be described later, the flexible substrate 11 is bent at two elongated bending portions 16 b extending in a direction orthogonal to the longitudinal direction of the flexible substrate 11. At this time, the two end portions 23a which are sides orthogonal to the length L3 direction on the flexible substrate bonding surface 23 of the bonding portion 21A position the side 16a which is a bending start point in the bending portion 16b of the flexible substrate 11.

  Further, when the flexible substrate 11 is folded between the adhesive portions 21A and the contact portions 21B on both sides of the H-shaped central connecting portion 21C, the back surface of the flexible substrate 11 The plurality of peripheral electronic components 15 mounted on 11B are formed with recesses 24 into which the peripheral electronic components 15 do not collide with the support member 21. When the flexible substrate 11 is bent, the flexible substrate 11 comes into contact with the contact portion 21B, so that the flexible substrate 11 is prevented from being bent excessively, and the plurality of peripheral electronic components 15 mounted on the back surface 11B are recessed. The imaging unit 100 (see FIG. 8) can be downsized.

  That is, the support member 21 comes into contact with at least one end portion 23a for positioning the bending start point in the bent portion 16b of the flexible substrate 11 and the peripheral electronic component mounting portion 20 on which the plurality of peripheral electronic components 15 are mounted. A contact portion 21B that prevents the substrate 11 from being bent excessively.

  The support member 21 is H-shaped because the case 32 is disposed around the imaging unit 100 shown in FIG. 8 as will be described later, so that the area that contacts or is close to the case 32 is larger. This is because the amount of heat released through the case 32 can be increased.

In addition, since the support member 21 includes the connecting portion 21C and the contact portion 21B extending from the contact portion 21A, the support member 21 has a good gripping property and good workability in manufacturing the imaging unit.
(Manufacture of imaging unit)
Next, the process of manufacturing the imaging unit will be described.
First, the flexible substrate 11 on which a plurality of peripheral electronic components 15 shown in FIGS. 1 and 2 are mounted is prepared. This is done by printing cream solder on a conventional flexible substrate 11 on which a predetermined wiring pattern 14 is formed, mounting electronic components by a mounter (not shown), and then reflowing a plurality of peripheral electrons. This is done by mounting the component 15 on the flexible substrate 11.

  Next, an adhesive 22 that is, for example, a thermosetting adhesive is applied to the support member adhesion region 16 on the back surface 11B of the flexible substrate 11, and the flexible substrate adhesion surface 23 of the support member 21 is used using a mounter (not shown). Then, the support member 21 is applied to the support member adhesion region 16 to which the adhesive 22 is applied and heated, and the support member 21 is adhered and fixed to the flexible substrate 21 by thermosetting of the adhesive 22 to obtain the state shown in FIG.

  Then, cream solder is applied to the plurality of image sensor lands 12 of the flexible substrate 11, the image sensor 1 is mounted on the mounting surface of the surface 11 </ b> A of the flexible substrate 11, and then the image sensor 1 is mounted on the flexible substrate 11 by solder reflow. Mount it fixed on top. FIG. 6 is a front view of the flexible substrate 11 on which the image sensor 1 is mounted. As shown in FIG. 6, each image sensor land 2 of the image sensor 1 is electrically connected to each image sensor land 12 of the flexible substrate 11 via the solder member 4.

  Next, the flexible substrate 11 is bent toward the back surface 11B side. At this time, the flexible substrate 11 is bent toward the back surface 11 </ b> B along the two sides 16 a of the support member adhesion region 16 that contacts the flexible substrate adhesion surface 23 of the support member 21. That is, the two end portions 23a of the bonding portion 21A, which are the two side portions of the flexible substrate bonding surface 23, serve as the bending starting points of the flexible substrate 11, and the flexible substrate 11 has two elongated bending portions 16b that are bending portions. It is bent at.

  The flexible substrate 11 is bent using a bending jig in a state where the side surface 25 (FIG. 5) of the support member 21 is gripped and fixed using a gripping member such as tweezers. The imaging unit 100 has a shape as shown in FIG. FIG. 7 is a front view of the imaging unit 100 showing a state in which the flexible substrate 11 is bent. In the state shown in FIG. 7, a filler 26 (FIG. 8) such as a thermosetting insulating adhesive such as an epoxy resin is poured into the recess 24 and cured. FIG. 8 is a front view of the imaging unit 100 showing a state in which the flexible substrate 11 is folded and the filler 26 is filled. At this time, as shown in FIG. 8, portions of the flexible substrate 11 on which the plurality of peripheral electronic components 15 are mounted are substantially parallel.

  In the two bent portions 16b of the flexible substrate 11, one or more grooves along the length L2 direction are formed on the surface of the resist layer on the surface 11A so that the flexible substrate 11 can be easily bent. Also good.

  Furthermore, before the filler 26 is poured into the recess 24, the portion of the flexible substrate 11 that contacts the contact surface 21B1 of the contact portion 21B and the contact surface 21B1 (see FIGS. 5 and 6) are bonded. Then, the flexible substrate 11 may be fixed to the support member 21, and then the filler 26 may be poured into the recess 24.

  The bent flexible substrate 11 contacts the contact portion 21B of the support member 21, and does not bend any more. Therefore, the peripheral electronic component 15 mounted on the back surface 11B enters the recess 24 and does not collide with the connecting portion 21C. As a result, the surface mount component mounted on the flexible substrate 11 is not damaged when the imaging unit is manufactured.

Further, both end portions 11a of the flexible substrate 11 are bent to the back surface 11B side which is the inner side of the bending, that is, to the axis side orthogonal to the imaging surface of the imaging device 1 and passing through the center of the imaging surface, as shown in FIG. In this state, an external wiring 31 is connected to each external land 13 with solder. The plurality of wires 31 are fixed by being bundled with a thread. The filling material 26 such as an insulating adhesive may be poured into the recess 24 as shown in FIG. 8, that is, after the wiring 31 is connected to the flexible substrate 11.
Further, the imaging unit 100 shown in FIG. 8 is accommodated in a case 32 indicated by a dotted line, and the insulating adhesive is poured into the case 32 again. The case 32 is made of, for example, metal, and is not intended before the electromagnetic noise from the imaging unit 100 or the electromagnetic noise to the imaging unit 100 is blocked, or before the imaging unit 100 is disposed in the distal end portion of the endoscope. Prevent damage by external force.
In the present embodiment, the external land 13 provided on the surface 11A of the flexible substrate 11 and the wiring 31 are connected to prevent the imaging unit 100 from becoming large and the conductive portion of the connected wiring 31 is particularly a case. The end portion 11a is bent to the back surface 11B side in order to prevent it from coming into contact with the back surface 32B. However, the present invention is not limited to this. For example, the end portion 11a is bent by providing an external land 13 on the back surface 11B of the flexible substrate 11. The enlargement of the imaging unit 100 may be prevented.

  As described above, in the imaging unit 100 configured by bending the flexible substrate 11 on which the imaging element 1 is mounted according to the above-described embodiment, imaging that is a surface on which the imaging element 1 of the flexible substrate 11 is mounted. Since the support member bonding region 16, which is the surface opposite to the element mounting surface 17, is supported by the support member 21, the terminal portion of the image sensor 1 is not peeled off from the flexible substrate 11 or the like. An imaging unit can be realized. Further, since the support member 21 has thermal conductivity, the support member 21 receives heat generated by the imaging device 1 and received through the flexible substrate 11 from the bonding portion 21A, the connecting portion 21C, and the contact portion 21B. Heat can be dissipated.

  Therefore, according to the imaging unit 100 of the above-described embodiment, the cross-sectional size of the imaging unit in the optical axis direction orthogonal to the imaging surface of the imaging element 1 can be equal to or substantially equal to the size of the imaging element 1. In addition to contributing to the reduction in the diameter of the distal end portion of the endoscope, it is possible to efficiently dissipate heat generated by the imaging device.

Hereinafter, modified examples will be described.
(Modification 1)
According to the above-described embodiment, as shown in FIG. 6, the flexible substrate 11 is bent after the imaging device 1 is mounted on the flexible substrate 11. In the first modification, the flexible substrate is bent. The image sensor 1 is mounted on the flexible substrate 11.

  FIG. 9 is a diagram for explaining a case where the imaging device 1 is mounted on the flexible substrate 11 after the flexible substrate is bent according to the first modification. That is, first, as shown in FIG. 9, the support member 21 is bonded to the back surface 11 </ b> B of the flexible substrate 11 with an adhesive 22, the flexible substrate 11 is bent, and the filling material 26 is filled therein to create the unit 101. .

  In the unit 101 of the flexible substrate 11 in which the filler 26 is filled, the plurality of imaging element lands 12 are bonded to the flexible substrate bonding surface 23 of the support member 21 and flattened on the imaging element mounting surface of the surface 11A. 17 is arranged. Therefore, even if the imaging device 1 with the cover glass 3 attached is mounted on the flexible substrate 11 with the unit 101 fixed, the plurality of imaging device lands 2 of the imaging device 1 are connected to the flexible substrate 11. Phenomenon such as peeling off does not occur.

Therefore, as in the first modification, the imaging device 1 may be mounted on the flexible substrate 11 after the flexible substrate 11 is bent.
(Modification 2)
In the embodiment described above, the support member 21 has thermal conductivity. However, in the second modification, the heat dissipation cable 33 is connected to the support member 21. FIG. 10 is a front view of the imaging unit 100A having the support member 21 to which the heat dissipation cable 33 is soldered.

  The heat dissipation cable 33 is connected to the contact portion 21B of the support member 21 by soldering or the like. As a result, the heat generated in the image pickup device 1 is transmitted to the support member 21 and then transmitted to the proximal end side of the insertion portion through the cable 33 to be radiated.

  Further, the support member 21 may be made of a material having conductivity in addition to the heat conductivity, and the cable 33 may be connected to the ground line. That is, a ground wire is connected to the cable 33 that is a heat dissipation member. As the adhesive 22, for example, a conductive adhesive for die bonding is used. In this case, in order to achieve an electrical connection between the back surface 11B and the support member 21, a part of the resist on the surface of the back surface 11B is removed to expose the wiring portion that becomes the ground potential, and the electrical connection is performed. Figured. The support member 21 is, for example, a metal having a high thermal conductivity, a ceramic such as aluminum nitride, or the like.

Therefore, according to the second modification, the terminal unit of the imaging element 1 is not peeled off from the flexible substrate 11 and the imaging unit 100A for endoscope with good heat dissipation can be realized. 21 can take the ground of the image sensor 1 in addition to the heat radiation of the image sensor 1.
(Modification 3)
The support member 21 of the above-described embodiment has an H-shaped cross section, but the contact portion of the support member of the third modification has a slope portion. FIG. 11 is a perspective view of a support member 21a according to the third modification. The support member 21a differs from the support member 21 shown in FIG. 5 in the configuration of the contact portion.

  The contact portion 21Ba of the support member 21a in FIG. 11 has two slope portions 21Bt that become narrower in the opposite direction to the connecting portion 21C. The inclined surface portion 21Bt is a portion where the both end portions 11a of the bent flexible substrate 11 are in contact with an axis side orthogonal to the imaging surface of the imaging device 1 and passing through the center of the imaging surface. Since there are two slope portions 21Bt, it is easy to connect the signal line to each external land 13.

Therefore, according to the supporting member 21a as shown in FIG. 11, the two end portions 11a of the bent flexible substrate 11 are not in contact with each other, and there are two inclined portions 21Bt. The work of connecting 31 is easy.
(Modification 4)
In the embodiment described above, the support member 21 is bonded to the central portion of the flexible substrate 11, but in the present modification, the support member 21 is bonded to one end portion of the flexible substrate 11.
FIG. 12 is a front view of an imaging unit 100B according to the fourth modification. As shown in FIG. 12, a support member 21 b is bonded to one end of the flexible substrate 11 </ b> A with an adhesive 22. A recess 24 into which the peripheral electronic component 15 mounted on the back surface of the flexible substrate 11A enters is formed between the adhesive portion 21Ab and the contact portion 21Bb of the support member 21b.

Therefore, according to this modification, it is possible to realize an imaging unit for an endoscope that does not peel off the terminal portion of the imaging element 1 from the flexible substrate 11 and has good heat dissipation.
(Modification 5)
In the above-described embodiment, the support member 21 is bonded to the central portion of the flexible substrate 11 and both sides of the central portion are bent. In the fourth modification, the support member is bonded to one end portion of the flexible substrate 11. The other end is bent, but the flexible substrate may be folded in three or four.

For example, the flexible substrate 11 has a plurality of mounting portions having a shape extending in three or four directions from the central portion, and the support member has three or four concave portions on three or four side surfaces. Formed.
Therefore, according to this modification, it is possible to realize an imaging unit for an endoscope that does not peel off the terminal portion of the imaging element 1 from the flexible substrate 11 and has good heat dissipation.

  As described above, according to the imaging unit for endoscope according to the above-described embodiment and each modification, in the imaging unit configured by bending the flexible board on which the imaging device is mounted, the terminal portion of the imaging device Thus, it is possible to realize an imaging unit for an endoscope that does not peel off from the flexible substrate and has good heat dissipation.

  In particular, according to the above-described embodiments and modifications, an endoscope imaging unit using a small-size imaging device such as a chip size package or a wafer level chip size package is arranged in accordance with its size. The diameter can be reduced.

  In addition, in the case of an image sensor in which a logic circuit is provided in the periphery of the image sensor such as a CMOS sensor, the amount of heat generation increases, but even in such a case, the heat dissipation can be improved and obtained by the image sensor. Image noise can be reduced.

Each of the above-described modifications may be combined with one or more other modifications within the applicable range.
The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Image pick-up element, 2 Image pick-up element land, 3 Cover glass, 4 Solder member, 11 Flexible board, 11A The surface of the flexible board 11, 11B The back surface of the flexible board 11, 12 Land for image pick-up elements, 13 Land for externals, 14 Wiring pattern, DESCRIPTION OF SYMBOLS 15 Peripheral electronic component, 16 Support member adhesion | attachment area | region, 16a Side of support member adhesion | attachment area | region 16, 16b Bending part, 17 Imaging device mounting surface, 18 Imaging device mounting part, 19 Peripheral electronic component mounting surface, 20 Peripheral electronic component mounting part, 21, 21a Support member, 21A, 21Ab Bonded part, 21B, 21Ba, 21Bb Abutting part, 21Bt Slope part, 21B1 Abutting surface, 21C, 21Cb Connecting part, 22 Adhesive, 23 Flexible substrate adhesive surface, 24 Recessed part, 25 Side surface of support member 21, 26 filler, 31 wiring, 32 cases .

Claims (5)

A first mounting portion having a first mounting surface for mounting at least an image sensor as a first electronic component; and a second mounting surface for mounting a second electronic component as an electronic component other than the image sensor. A flexible board having a second mounting part, and a bent part provided between the first mounting part and the second mounting part,
A support member that is provided on the back side of the first mounting surface of the first mounting portion, has thermal conductivity that conducts heat generated from the imaging element, and supports the flexible substrate;
Have
The support member includes at least one end portion for positioning a bending start point in the bent portion of the flexible substrate, and an abutting portion that prevents the flexible substrate from being bent excessively by contacting the second mounting portion. An imaging unit for an endoscope, comprising:   The endoscope imaging unit according to claim 1, wherein the flexible substrate includes a plurality of the second mounting portions.   3. The endoscope imaging unit according to claim 1, wherein the second electronic component enters a recess provided in the support member when the flexible substrate is bent at the bent portion. 4. . Having a heat dissipation member connected to the support member;
The endoscope imaging unit according to any one of claims 1 to 3, wherein a ground wire is connected to the heat radiating member.   The endoscope imaging unit according to claim 1, wherein the support member has a flat surface that supports the flexible substrate.

Images