JP2012070272A - Heat radiation structure for image pickup element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiation structure for an image pickup element which can effectively radiate heat without generating noise.SOLUTION: An image pickup element 11 mounted on an image pickup element mounting substrate 12 is positioned in a rectangular opening of an image pickup element holding plate 13, where an inclination adjustment relative to the image pickup element holding plate 13 is made such that an imaging plane faces an optical axis perpendicularly, and is then fixedly bonded with an adhesive filling the surrounding spacing. The image pickup element mounting substrate 12 has a hole 12d formed in a position corresponding to a rear surface of the image pickup element 11, and a radiation member 18 is brought in contact with the rear surface of the image pickup element 11 via the hole 12d. The radiation member 18 is an elastic member held on a radiation plate 19, and the image pickup element 11 is thermally connected to the radiation plate 19 of high thermal conductivity via the radiation member 18.

Description

  The present invention relates to a heat dissipation structure for an image sensor mounted on a substrate.

  An image sensor for high pixels generates a large amount of heat and requires a highly efficient heat dissipation structure. Further, when the number of pixels of the image sensor increases, an inclination adjustment structure is required, and the position of the image sensor is not fixed, so that connection with a heat radiating component is difficult.

  FIG. 6 is a perspective view showing a conventional image sensor unit. In the conventional image sensor unit, the image sensor mounting substrate 61 on which the image sensor is mounted is fastened to the image sensor holding plate 62 with screws. The image sensor holding plate 62 is fastened to the image sensor holder 64 at the rear part of the lens barrel 63 with screws 65a, 65b, 65c.

  As described above, when the amount of heat generated by the image sensor increases due to the increase in the number of pixels, it is necessary to take measures to actively dissipate the generated heat. For example, a configuration in which the image sensor holding plate 62 and a heat sink (not shown) are pressed against each other and heat generated by the image sensor is guided to the heat sink through the image sensor mounting substrate 61 and the image sensor holding plate 62 can be considered.

  On the other hand, with an increase in the size of the image sensor, it is required to accurately orient the image pickup surface of the image sensor with respect to the optical axis. A large image sensor has a shallower depth of focus than a small image sensor. Therefore, when the image pickup surface of the image pickup device is assembled in a state where the image pickup surface is inclined with respect to the optical axis, imaging blur tends to occur in the peripheral portion of the image pickup surface where the amount of displacement in the optical axis direction increases. In particular, in the case of a large-sized image sensor with a large amount of displacement in the optical axis direction in the peripheral part, the imaging blur becomes noticeable. Therefore, in the case of a large image sensor, the allowable amount of positional deviation in the optical axis direction of the imaging surface is reduced.

  When the image sensor unit is assembled in this way, a configuration for setting the image pickup surface of the image sensor in a direction perpendicular to the optical axis is required. In general, for example, in the conventional example shown in FIG. 6, the inclination of the image sensor is adjusted by interposing a washer at three fastening portions (screws 65a, 65b, 65c) that fix the image sensor holding plate 62 to the image sensor holder 64. The imaging surface is oriented in a direction perpendicular to the optical axis by, for example, biasing with a spring.

  However, when the tilt of the image sensor is adjusted with such a configuration, the tilt of the image sensor holding plate 62 with respect to the surrounding components varies from product to product, and as a result, it is difficult to thermally connect to the heat sink. Become.

  In order to effectively dissipate heat, it is necessary to press-contact the image sensor holding plate 62 and the heat radiating plate using means such as fastening with screws. However, since the image sensor mounting substrate 61 and the image sensor holding plate 62 are integrated by fastening, when the image sensor holding plate 62 and the heat radiating plate having a large variation in inclination are fastened, a load is applied to the image sensor holding plate 62. There is a possibility that the optical performance is remarkably impaired by affecting the positional accuracy of the image sensor.

  Various means for solving the above problems are disclosed. For example, Patent Document 1 discloses a mounting unit for an image sensor including a tilt adjusting unit. This is because the image pickup device package whose inclination is adjusted is bonded to the reference plate, and the adhesive uses a highly heat conductive adhesive to enhance the heat dissipation effect.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a tilt adjustment unit for a semiconductor substrate on which an image sensor in an image sensor package is formed. In this embodiment, the inclination of the semiconductor substrate is adjusted by a semiconductor substrate urged by a pressing member such as a leaf spring and an inclination adjusting member (for example, a screw). It is disclosed.

JP 2005-051518 A JP 2006-340299 A

  In the prior art disclosed in Patent Document 1 described above, an adhesive having high thermal conductivity is used. Generally, an adhesive having high thermal conductivity contains carbon or metal. If a material with high electrical conductivity such as carbon or metal is contained in the adhesive in this way, it will cause noise, so use an adhesive with high thermal conductivity as a means to bond the image sensor. It is not preferable to do.

  Further, in the prior art disclosed in Patent Document 2, an adjustment unit for an image sensor package and a heat dissipation structure are shown. However, since the package has a package structure, it cannot be applied to mounting a general-purpose image sensor.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a heat dissipation structure for an image sensor that can effectively dissipate heat without generating noise.

  The heat dissipation structure for an image pickup device according to the present invention includes a substrate on which an image pickup device is mounted and a hole or notch formed at a position facing the back surface of the image pickup device, and the image pickup through the hole or the notch. And a heat dissipating member in contact with the back surface of the element.

  According to the present invention, since the heat dissipation member is brought into contact with the back surface of the image sensor, it is not necessary to use an adhesive with high thermal conductivity, and the image sensor that can effectively dissipate heat without generating noise. A heat dissipation structure can be provided.

It is a disassembled perspective view of the image sensor unit which has the heat dissipation structure of the image sensor concerning an embodiment. It is a perspective view which shows the state which assembled | attached the image pick-up element unit to the image pick-up element holder of the rear part of a lens-barrel. It is sectional drawing of an image pick-up element unit and its periphery. It is an external view of an image sensor unit, (a) is a front view of the image sensor unit, (b) is a rear perspective view of the image sensor unit. It is a disassembled perspective view of the image pick-up element unit which has the thermal radiation structure of the image pick-up element which concerns on other embodiment. It is a figure for demonstrating the conventional image pick-up element unit.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is an exploded perspective view of an image sensor unit 2 having a heat dissipation structure for an image sensor according to the first embodiment. FIG. 2 is a perspective view showing a state in which the image sensor unit 2 is assembled to the image sensor holder 16 at the rear of the lens barrel 1. FIG. 3 is a cross-sectional view of the image sensor unit 2 and its periphery. 4A and 4B are external views of the image sensor unit 2. FIG. 4A is a front view of the image sensor unit 2, and FIG. 4B is a rear perspective view of the image sensor unit 2. FIG.

  As shown in FIG. 1, the image sensor 11 is mounted on an image sensor mounting substrate 12. In addition, the image sensor 11 mounted on the image sensor mounting substrate 12 is tilt-adjusted with respect to the image sensor holding plate 13 so that the imaging surface is directed perpendicular to the optical axis. In addition, the image pickup device 11 is positioned in the rectangular opening of the image pickup device holding plate 13 and is bonded and fixed with an adhesive so as to fill the surrounding gap.

  The image sensor holding plate 13 to which the image sensor 11 is fixed is fixed to the image sensor holder 16 with screws 17a, 17b, and 17c. A rubber 15 having an opening is disposed in front of the image sensor 11, and a low-pass filter 14 is disposed in front of the rubber 15. The rubber 15 and the low-pass filter 14 are sandwiched between the image sensor 11 and the holder 16.

  A heat radiating plate 19 is disposed behind the imaging element mounting substrate 12.

  Here, in FIG. 1, the image pickup device mounting substrate 12 is illustrated in a simplified manner, but as shown in FIGS. 2 to 4, a rigid flexible substrate is used as the image pickup device mounting substrate 12. The rigid flexible substrate is an integration of a flexible printed circuit board and a rigid substrate, and includes a rigid portion made of a hard material such as glass epoxy and a flexible portion such as polyimide. As shown in FIGS. 2 and 3, the substrate portion 12a on which the image sensor 11 is mounted and the substrate portion 12b disposed on the back side of the heat radiating plate 19 are connected via a flexible portion 12c. By using such a rigid flexible substrate, it is possible to avoid an increase in the size of the image sensor mounting substrate 12. Further, as shown in FIG. 4B, there is an effect that the load when the cable is inserted into the connectors 44a, 44b, 44c provided on the board portion 12b is not transmitted to the bonded portion of the image sensor 11.

  A hole 12d is formed in the image sensor mounting substrate 12 (substrate portion 12a) at a position facing the back surface of the image sensor 11 (that is, the non-imaging surface opposite to the imaging surface). At the stage where the image pickup device 11 is bonded to the image pickup device holding plate 13, the tip of the suction nozzle is brought into contact with the back surface of the image pickup device 11 through the hole 12 d to support the image pickup device mounting substrate 12. The image sensor holding plate 13 is fixed at an appropriate position of the jig. In this state, the image sensor 11 sucked by the suction nozzle is adjusted in the position in the XY direction shown in FIG. 1 and then adhered to the image sensor holding plate 13. At this time, the tip surface of the suction nozzle and the surface on which the image sensor holding plate 13 is installed are set on the same plane with high accuracy, and the image sensor 11 and the image sensor holding plate 13 can be positioned and bonded with high accuracy. it can.

  The heat dissipation member 18 comes into contact with the back surface of the image sensor 11 through the hole 12 d of the image sensor mounting substrate 12. The heat radiating member 18 is an elastic member and is held by the heat radiating plate 19. Thereby, the image sensor 11 is thermally connected to the heat radiating plate 19 having high thermal conductivity via the heat radiating member 18.

  With the above configuration, a high heat dissipation effect can be obtained by bringing the heat dissipation member 18 into direct contact with the back surface of the image sensor 11 and guiding the heat generated in the image sensor 11 to the heat sink 19.

  In addition, the inclination of the back surface of the image sensor 11 with respect to the heat radiating plate 19 varies due to the tilt adjustment. However, the variation in inclination can be absorbed by the elasticity of the heat radiation member 18 in contact with the image sensor 11. Further, the back surface of the image sensor 11 with which the heat radiating member 18 contacts is close to the center of rotation at the time of tilt adjustment, and thus is not easily affected by tilt.

  Further, since it is not necessary to use an adhesive with high thermal conductivity, there is no possibility of giving noise to the signal.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary. For example, in the above embodiment, the hole 12d is formed in the image sensor mounting substrate 12 at a position facing the back surface of the image sensor 11, but a notch 12e may be formed as shown in FIG.

1: lens barrel, 2: imaging element unit, 11: imaging element, 12: imaging element mounting substrate, 12d: hole, 12e: notch, 13: imaging element holding plate, 16 ”imaging element holder, 18: heat dissipation member , 19: Heat sink

Claims (5)

A substrate on which an image sensor is mounted and a hole or notch is formed at a position facing the back surface of the image sensor;
A heat dissipation structure for an image sensor, comprising: a heat dissipating member that contacts the back surface of the image sensor through the hole or notch.   The heat dissipation structure for an image sensor according to claim 1, wherein the heat dissipation member is held by a heat dissipation plate.   The heat dissipation structure for an image sensor according to claim 1, wherein the heat dissipation member is an elastic member.   4. The heat dissipation structure for an image sensor according to claim 1, wherein the hole or the notch has a size allowing a suction nozzle for sucking the image sensor to be inserted. 5.   The image pickup device according to claim 1, further comprising an image pickup device holding plate to which a periphery of the image pickup device is bonded after the inclination of the image pickup device is adjusted. Heat dissipation structure.

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