JP2013172168A - Heat dissipation device, and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compact in the thickness direction.SOLUTION: An image sensor 18 has a light-receiving part for receiving the object light, being focused by a photographic lens, on the surface. A pair of FPCs 31, 32 have one ends connected with the image sensor 18, and the other ends extending to the right and left. A fixing plate 22 has an imaging aperture 27 provided on the photographing optical axis 13a, and the image sensor 18 is fitted to the aperture 27 from the back and fixed in place. A heat dissipation sheet 25 has an element contact part 41 which is in contact with the back of the image sensor 18, FPC shields 42, 43 provided to extend from the element contact part 41 to the right and left so as to cover the back of the flexible wiring boards 31, 32, and fixing plate contact parts 44-47 projecting bilaterally in the width direction of the FPC shields 42, 43 and coming into contact with the fixing plate 22, respectively. Heat generated in the image sensor 18 is released to the fixing plate 22, while covering the flexible wiring boards 31, 32 from the back and imparting shield effect.

Description

  The present invention relates to a heat dissipation device and an imaging device.

  The image sensor causes a temperature rise due to heat generated during driving, and noise such as dark current is generated with the temperature rise. This noise due to heat causes a decrease in the function of the image sensor, such as a decrease in image quality, making it difficult to capture high quality images with the image sensor.

  Therefore, as a heat dissipation structure of the imaging device, a structure is known in which a heat dissipation member is thermally coupled between the back surface of the image sensor and the device housing, and heat generated in the image sensor is released to the device housing by the heat dissipation member.

JP 2008-219861 A

  However, when the heat radiating member is provided on the back surface of the imaging device, there is a problem that, for example, the body becomes thick due to the arrangement space of the heat radiating member, and the camera becomes large.

  SUMMARY An advantage of some aspects of the invention is that it provides a heat dissipation device and an imaging device that are reduced in size.

  In the heat dissipation device exemplifying the present invention, a photoelectric conversion element having a light receiving portion on the surface, one end of the photoelectric conversion element is electrically connected to the photoelectric conversion element, and the other end is directed to at least one direction in a plane substantially parallel to the surface. An extended flexible wiring board, an opening for allowing light to pass through the light receiving portion, a fixing plate for fixing the photoelectric conversion element, an element contact portion that contacts the back surface of the photoelectric conversion element, and the A pair of fixed plate contact portions that extend in one direction from the element contact portion and cover the back of the flexible wiring board and project in both the width direction of the FCP shield portion and respectively contact the fixed plate; And a heat dissipating sheet.

  According to the present invention, since the heat radiation sheet is provided to cover the flexible wiring board from behind and release the heat generated in the photoelectric conversion element to the fixed plate while providing a shielding effect, it is possible to reduce the size in the thickness direction.

It is sectional drawing which shows the principal part of the electronic camera using the imaging part of this invention. It is a disassembled perspective view which shows an imaging part. It is a disassembled perspective view which shows an imaging unit. It is an expanded view which shows a thermal radiation sheet. It is sectional drawing which shows an imaging part. It is a perspective view which shows an imaging part. It is a perspective view which shows the imaging part of the other example which provided four FPC so that it might protrude in four directions. It is an expanded view which shows the thermal radiation sheet used with the imaging part demonstrated in FIG. It is a perspective view which shows the imaging part demonstrated in FIG.

  An electronic camera 11 to which the present invention is applied includes a camera body 12 and an interchangeable lens 14 having a photographing lens 13 as shown in FIG. The interchangeable lens 14 is provided with a lens mount 15 and is detachably attached to a body mount 16 provided on the camera body 12. A dark box 17 is built in the camera body 12 after the body mount 16, and after the dark box 17, an imaging unit 19 having a solid-state imaging device (hereinafter referred to as “imaging device”) 18 serving as a heat source is fixed. Yes. The dark box 17 includes an opening 20 for allowing a subject light flux that has passed through the photographing lens 13 to enter the light receiving portion 18a, and a box portion 21 that keeps the light shielding portion between the photographing lens 13 and the light receiving portion 18a of the image sensor 18. . Reference numeral 13 denotes a photographing optical axis.

As shown in FIG. 2, the imaging unit 19 includes a fixed plate 22, an imaging unit 24 having a transparent substrate 23 such as glass, a heat radiation sheet 25, and a pressing plate 26.
The fixing plate 22 is made of a material having a high thermal conductivity (high thermal conductivity) and is formed in a horizontally long rectangular shape. The fixing plate 22 is arranged substantially at the center, and has an imaging opening 27 and a plurality of mounting holes 28. Is formed. A stepped surface 29 that is recessed by one step is formed on the periphery on the back side of the opening 27, and the transparent substrate 23 is fitted into the stepped surface 29 from the back side. The stepped surface 29 functions to prevent the transparent substrate 23 from coming out forward and to be positioned vertically and horizontally. The plurality of attachment holes 28 are holes for attachment to the dark box 17.

The imaging unit 24 includes an imaging element 18, a transmissive substrate 23, and a pair of flexible printed circuit boards (FPC (Flexible Printed Circuits)) 31 and 32.
As shown in detail in FIG. 3, the transparent substrate 23 is formed with a plurality of conductor patterns 34 on the back surface, divided into left and right (horizontal directions). The rows of conductor patterns 34 on the left and right are formed in a region that does not block the subject luminous flux incident on the light receiving portion 18a.

  The image sensor 18 is configured by a CCD or a CMOS type. Specifically, the imaging element 18 includes a light receiving unit 18a that receives subject light on a surface of a substrate such as a silicon substrate, a functional unit (not shown) including various circuits necessary for an imaging function, a functional unit, This is a bare-chip semiconductor device including a plurality of electrically connected electrodes.

The light receiving unit 18a is realized by using a plurality of pixels, a micro lens, a color filter, and the like that are two-dimensionally arranged. The light receiving unit 18a receives subject light imaged through a photographing optical system including the photographing lens 13 and the transmissive substrate 23, and performs photoelectric conversion processing on the received light.
The functional unit is formed outside the light receiving unit 18a, and includes various circuits necessary for realizing an imaging function such as a driver circuit. The functional unit generates an image signal of the subject based on the signal subjected to the photoelectric conversion process by the light receiving unit 18a. The plurality of electrodes 36 are formed in the outer periphery of the light receiving portion 18a and the functional portion, that is, in the left and right regions that do not block the subject light flux.

  The imaging element 18 is flip-chip mounted on a plurality of electrodes 37 provided at one end of the conductor pattern 34 of the transmissive substrate 23 through bumps provided on each electrode 36. In addition, a plurality of electrodes 39 provided at one ends of the FPCs 31 and 32 are respectively connected to the electrode 38 at the other end of the plurality of conductor patterns 34 via an anisotropic conductive film.

  The pair of FPCs 31 and 32 are arranged such that the other ends 31 b and 32 b protrude from the left and right sides in a state where the one ends 31 a and 32 a are electrically connected to the transmissive substrate 23. As a result, the pair of FPCs 31 and 32 send the image signal generated by the functional unit to the image processing circuit that performs various image processing, and transmits a control signal and the like for controlling the driver circuit and the like to the functional unit. To do. In addition, as FPC31 and 32, you may use what has the rigid part which mounts an image process part, a driver circuit, etc. in the other end.

  The heat dissipation sheet 25 is formed into a sheet shape with a material having high thermal conductivity and high conductivity (high conductivity). Specifically, as shown in detail in FIG. 4, the heat dissipation sheet 25 includes an element contact portion 41 disposed substantially at the center of the sheet, and left and right FPC shields disposed to extend to the left and right sides of the element contact portion 41. It is comprised by the fixed plate contact parts 44-47 extended and arrange | positioned with respect to the parts 42 and 43 and the left and right FPC shield parts 42 and 43. The element contact portion 41 is adhered to the back surface of the imaging element 18 with an adhesive.

  The left and right FPC shield portions 42 and 43 cover the left and right FPCs 31 and 32 from the back surface and impart electromagnetic shielding performance to the FPCs 31 and 32. Note that the left and right FPC shield portions 42 and 43 may be bonded to the back surfaces of the FPCs 31 and 32 with an adhesive. The four fixed plate contact portions 44 to 47 are folded back toward the surface of the fixed plate 22 at the position of the dotted line shown in the figure, and are bonded to the front surface of the fixed plate 22 with an adhesive as shown in FIG. . In addition, as an adhesive agent, what has high heat conductivity and high electroconductivity is used.

As the heat dissipation sheet 25, it is preferable to use a material having high heat dissipation and electromagnetic shielding properties, for example, a composite material such as carbon graphite, a material such as copper foil or aluminum foil.
As shown in FIG. 6, both ends of the pressing plate 26 are fixed to the fixed plate 22, and the image sensor 18 is pressed toward the fixed plate 22 via the element contact portion 41 by a pressing portion 48 provided therebetween. . Thereby, the imaging unit 24 is prevented from coming out of the opening 27 of the fixed plate 22. It is desirable that the pressing plate 26 is also made of a material having properties of high heat dissipation and high conductivity. In addition, since the heat radiating sheet 25 is pressed against the image sensor 18 by the pressing plate 26, the element contact portion 41 and the back surface of the image sensor 18 do not have to be bonded with an adhesive. Conversely, when the element contact portion 41 and the back surface of the imaging element 18 are bonded with an adhesive, the pressing plate 26 may be omitted.

  Here, a method for manufacturing the imaging unit 19 according to the present embodiment will be briefly described. First, the conductor pattern 34 is formed on the left and right sides of the transparent substrate 23 by a printing method or the like. Thereafter, bumps are provided on each of the plurality of electrodes 36 on the left and right surfaces of the image sensor 18. Then, each bump of the image sensor 18 is flip-chip connected to each electrode 37 provided at one end of the conductor pattern 34 of the transmissive substrate 23 to fix the image sensor 18 to the transmissive substrate 23. Thereafter, the plurality of electrodes 39 provided at the one ends 31 a and 32 a of the FPCs 31 and 32 are connected to the plurality of electrodes 38 at the other end of the conductor pattern 34 by an anisotropic conductive film, for example, an anisotropic conductive adhesive film. As a result, the imaging unit 24 is completed in a form in which the other ends 31b, 32b of the pair of FPCs 31, 32 extend from the back of the transparent substrate 23 arranged in a posture orthogonal to the photographing optical axis 13a.

  In the completed imaging unit 24, the transparent substrate 23 is fitted into the opening 27 provided in the fixing plate 22, and the front peripheral edge of the transparent substrate 23 is brought into contact with the stepped surface 29 of the opening 27. Thereafter, the heat radiation sheet 25 is placed from behind the imaging unit 24. At this time, the element contact part 41 which is a main part is aligned with the back surface of the image sensor 18 and covered with the left and right FPC shield parts 42 and 43 so as to cover the back surfaces of the left and right FPCs 31 and 32. Then, the four fixed plate contact portions 44 to 47 are folded back toward the front surface of the fixed plate 22. Adhesive is applied in advance to the element contact portion 41 and the four fixing plate contact portions 44 to 47, so that the element contact portion 41 is provided on the back surface of the image sensor 18 and the four fixing plate contact portions 44. ˜47 are respectively bonded to the front surface of the fixing plate 22. Finally, the image pickup unit 19 is completed by fixing the pressing plate 26 with fixing means such as a screw. The fixed plate contact portions 44 to 47 may be contacted or bonded at the upper and lower ends of the fixed plate 22 without being folded back to the front surface of the fixed plate 22.

  The completed imaging unit 19 is fixed to the dark box 17 described with reference to FIG. 1, and thereafter, the other ends 31b and 32b of the pair of FPCs 31 and 32 are connected to a predetermined connecting unit (not shown). As a result, the heat generated in the image sensor 18 is transferred to the dark box 17 via the heat dissipation sheet 25 and the fixed plate 22 while providing a shielding effect to the FCPs 31 and 32, and is transmitted from the dark box 17 to the camera body 12. It can dissipate heat to the outside.

  In the imaging unit 24 of the above embodiment, the FPCs 31 and 32 are provided on the left and right sides of the imaging element 18. However, the present invention is not limited to this, and may be provided on the upper and lower sides. It is good also as a form which provided one FPC only in any one of upper, lower, left, and right. In either case, the heat dissipation sheet 25 may be provided with fixing plate contact portions at both ends in the width direction of the FPC shield portion.

  Further, as shown in FIG. 7, FPCs 50 to 53 may be provided in four directions, up, down, left, and right when the image sensor 18 is viewed from the back. In the case of such an imaging unit 55, a heat radiation sheet 56 having a form as shown in FIG. 8 is used.

  Specifically, the heat radiation sheet 56 is provided with FPC shield portions 58 to 61 on the four sides of the element contact portion 57, respectively, above and below the left and right FPC shield portions 58 and 59. 65 may be provided, and the upper and lower FPC shield portions 60 and 61 may be formed in the shape provided with the FPC folded portions 66 to 69 at both ends in the width direction. Then, as shown in FIG. 9, the FPC folding portions 66 to 69 are folded toward the front of the FPCs 52 and 53 extending upward and downward to wrap the FPCs 52 and 53. The folded portions 66 to 69 may be adhered to the front surfaces of the FPCs 52 and 53 with an adhesive.

  Moreover, it is good also as a form which abbreviate | omitted any of FPC50-53 provided and extended to four directions, and extended FPC to three sides. In this case, what is necessary is just to make a heat radiating sheet by the expansion | deployment shape which extended the fixing plate contact part to the said three directions with respect to the element contact part.

In the above embodiment, the heat source is described as the solid-state imaging device 18, but the present invention is not limited to this and may be a photoelectric conversion device such as a photodiode.
Further, in each of the above embodiments, the heat radiating sheet such as carbon graphite or copper foil is described. However, the present invention is not limited to this, and in a flat bag body made of a film having high conductivity on the surface. It is good also as a thermal radiation sheet which included the gel-like heat carrier which has a cooling function. When this is used, since the gel-like heat medium is plastically deformed with a small pressure, even if the heat generating surface is uneven, it can be brought into close contact with a large area, and the efficiency of heat absorption and heat dissipation can be improved.

  Furthermore, the imaging apparatus of the present invention is not limited to an electronic camera, but may be a video camera with a function of recording video and audio on a memory card or hard disk, a mobile phone with a camera, or the like. Moreover, it is good also as an imaging device used for an electron microscope apparatus.

DESCRIPTION OF SYMBOLS 11 Electronic camera 19 Image pick-up part 13a Image pick-up optical axis 22 Fixing plate 24,55 Imaging unit 25,56 Radiation sheet 26 Pressing plate 31,32 FPC

Claims (5)

A photoelectric conversion element having a light receiving portion on the surface;
A flexible wiring board having one end electrically connected to the photoelectric conversion element and the other end extended in at least one direction in a plane substantially parallel to the surface;
An opening for allowing light to pass through the light receiving portion is provided, and a fixing plate for fixing the photoelectric conversion element;
In both the element contact part that contacts the back surface of the photoelectric conversion element, the FPC shield part that extends from the element contact part in the one direction and covers the back of the flexible wiring board, and the width direction of the FCP shield part A heat dissipating sheet having a pair of fixing plate contact portions protruding and contacting each of the fixing plates;
A heat dissipation device comprising: The heat dissipation device according to claim 1,
The flexible wiring board is provided in a pair extending in the one direction and the opposite direction,
The FPC shield part is provided in a pair so as to extend from the element contact part in the one direction and the other direction so as to individually cover the back of each flexible wiring board,
The fixed plate contact portions are respectively provided on both sides of each FPC shield portion.
A heat dissipation device characterized by that. The heat dissipation device according to claim 1,
The flexible substrate is provided to extend in four directions including the one direction,
Four FPC shield parts are provided so as to cover each of the four sides from behind,
The fixed plate contact portions are respectively provided on both sides of each FPC shield portion.
A heat dissipation device characterized by that. In the heat radiating device according to any one of claims 1 to 3,
The heat dissipating device, wherein the fixing plate contact portion is bent forward and contacts the front surface of the fixing plate. A solid-state imaging device having a light receiving portion on the surface for receiving subject light imaged by a photographing lens;
A flexible wiring board having one end electrically connected to the solid-state imaging device and the other end extending in at least one direction of a plane substantially parallel to the surface;
A fixing plate having an imaging opening provided on the imaging optical axis and fixing the photoelectric conversion element;
An element contact portion that contacts the back surface of the solid-state imaging device, an FPC shield portion that extends in the one direction from the element contact portion and covers the back of the flexible wiring board, and a width direction of the FCP shield portion A heat dissipating sheet having a pair of fixing plate contact portions protruding and contacting each of the fixing plates;
An imaging apparatus comprising:

Images