JP2011041196A - Heat block structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat block structure in which heat transfer between electronic components is blocked and a decline in function of the electronic component due to a temperature rise can be prevented. <P>SOLUTION: In an exemplary embodiment, a heat block structure 100 includes a surrounding rigid body 15 surrounding a solid-state image sensing device 11. The surrounding rigid body 15 has a multilayer cross-sectional structure including: an electromagnetic wave absorption layer of a rigid body 15a that absorbs an electromagnetic wave; and a reduced pressure layer 15b in which a pressure is reduced as compared with an atmospheric pressure. The rigid body 15a absorbs a thermal energy of heat radiation and blocks the heat radiation between the solid-state image-sensing device 11 and a DSP 21. The reduced pressure layer 15b suppresses heat convection and blocks the heat convection between the solid-state image sensing device 11 and the DSP 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat blocking structure that blocks heat transfer between electronic components such as semiconductor elements.

  Conventionally, various types of electronic imaging devices such as a digital still camera such as a digital single-lens reflex camera, a digital video camera, an endoscope for observing the inside of an organ of a subject, and a mobile phone having an imaging function have been used. Has appeared. The electronic imaging device includes an imaging unit including a solid-state imaging device such as a CCD or a CMOS and an optical system such as a lens. The electronic imaging apparatus forms an optical image of a subject on a light receiving unit of a solid-state imaging device by an optical system, and captures an image of the subject by photoelectric conversion processing of the solid-state imaging device.

  In recent years, in electronic imaging devices, there is an increasing demand for downsizing of the solid-state imaging device as well as higher pixels and higher speed processing. For this reason, high-performance and high-density mounting of electronic components such as a solid-state imaging device and a DSP (Digital Signal Processor) mounted in the electronic imaging device are in progress. With such high performance and high density mounting of electronic components, the amount of heat generated during operation of the electronic components increases, and mutual heat transfer between the electronic components is likely to occur, and the temperature of the electronic components due to heat transfer is increased. Due to the increase, the function of the electronic component is degraded.

  In particular, the solid-state imaging device is an analog device and is easily affected by heat caused by mutual thermal interference between electronic components arranged in the vicinity. For example, a DSP that performs overall operation control of an electronic imaging apparatus is a semiconductor element that generates heat while operating for a long time. The heat transfer between the DSP that can be a heat source and the solid-state image sensor causes a temperature rise of the solid-state image sensor, and noise such as dark current is generated with the temperature rise of the solid-state image sensor. This heat noise causes a decrease in the function of the solid-state imaging device such as a reduction in image quality, making it difficult to capture high-quality images with the solid-state imaging device.

  As a conventional technique for suppressing the mutual heat transfer between the electronic components as described above, for example, a gap is formed between the DSP and the solid-state image sensor by interposing a spacer between the DSP and the solid-state image sensor. If there is a thing (refer patent document 1), the thing which has arrange | positioned the heat insulation member between the heat sink connected to the solid-state image sensor so that heat conduction is possible, and the heat sink connected to the integrated circuit so that heat conduction is possible (See Patent Document 2).

Japanese Patent No. 4036694 JP 2007-174526 A

  By the way, in heat transfer between objects, thermal conduction, which is a phenomenon in which thermal energy is transmitted by vibration of atoms or molecules, or movement of free electrons, and thermal radiation (thermal radiation), a phenomenon in which thermal energy is emitted from an object as electromagnetic waves. ) And thermal convection, which is a phenomenon in which thermal energy is moved by the flow of a fluid such as gas.

  However, in the related art disclosed in Patent Document 1 described above, it is possible to suppress heat conduction between electronic components, but it is difficult to suppress heat radiation, and thus heat transferred by heat radiation is difficult. The energy causes a temperature rise of the electronic component, and there is a problem that the function of the electronic component is lowered by this temperature rise.

  Moreover, in the prior art described in Patent Document 2 described above, it is difficult to absorb the thermal energy transmitted as electromagnetic waves by the heat insulating member between the heat radiating plates. Therefore, the electronic component using the thermal energy transmitted by thermal radiation As a result, there is a problem that the function of the electronic component deteriorates due to the temperature rise.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat blocking structure capable of blocking heat transfer between electronic components and preventing functional deterioration of the electronic components due to temperature rise. .

  In order to solve the above-described problems and achieve the object, the heat blocking structure according to the present invention has a multilayer cross-sectional structure having an electromagnetic wave absorbing layer that absorbs electromagnetic waves and a reduced pressure layer that is depressurized compared to the outside air, An enclosure rigid body that surrounds the first electronic component on the first circuit board, and the second electronic component on the second circuit board disposed outside the enclosure rigid body and the first electronic component It is characterized in that the heat transfer between them is cut off.

  In the above-described invention, the heat blocking structure according to the present invention is disposed on a connection board that connects the first circuit board and the second circuit board, and absorbs heat conducted to the connection board. It further comprises an endothermic body.

  In the heat blocking structure according to the present invention as set forth in the invention described above, the electromagnetic wave absorbing layer is formed as an outer layer of the surrounding rigid body, and the reduced pressure layer is sealed by the outer layer.

  In the heat blocking structure according to the present invention as set forth in the invention described above, the surrounding rigid body is formed by an electromagnetic wave absorbing member that forms the electromagnetic wave absorbing layer and seals the reduced pressure layer.

  In the heat blocking structure according to the present invention as set forth in the invention described above, the decompression layer is a vacuum layer.

  The heat blocking structure according to the present invention comprises a multilayer cross-sectional structure having an electromagnetic wave absorbing layer that absorbs electromagnetic waves and a reduced pressure layer that is depressurized compared to the outside air in the above-described invention. It further comprises another surrounding rigid body for surrounding.

  According to the heat blocking structure of the present invention, the surrounding rigid body has a multilayer cross-sectional structure having an electromagnetic wave absorbing layer that absorbs electromagnetic waves and a reduced pressure layer that is depressurized compared to the outside air, and the first rigid structure on the first circuit board. In order to surround one electronic component and to block heat transfer between the second electronic component on the second circuit board disposed outside the surrounding rigid body and the first electronic component, The electromagnetic energy absorbing layer can absorb thermal energy due to thermal radiation, and the surrounding rigid body decompression layer can suppress thermal convection. As a result, the heat transfer between the first electronic component and the second electronic component can be interrupted, and the temperature rise of the first electronic component and the second electronic component can be reduced. As a result, the first electronic component due to the temperature rise can be reduced. There is an effect that the functional degradation of the electronic component and the second electronic component can be prevented.

FIG. 1 is a schematic cross-sectional view showing a configuration example of a semiconductor device provided with a heat blocking structure according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of the outer shape of the surrounding rigid body and the multilayer cross-sectional structure. FIG. 3 is a schematic diagram for explaining the operation of the heat shielding structure according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a configuration example of a semiconductor device provided with a heat blocking structure according to a modification of the embodiment of the present invention.

  Embodiments of a heat shield structure according to the present invention will be described below in detail with reference to the drawings. Hereinafter, as an example of a plurality of electronic components, a solid-state imaging device and a DSP built in an electronic imaging device will be exemplified, and a heat blocking structure that blocks heat transfer between the solid-state imaging device and the DSP will be described. The present invention is not limited by this embodiment.

(Embodiment)
FIG. 1 is a schematic cross-sectional view showing a configuration example of a semiconductor device provided with a heat blocking structure according to an embodiment of the present invention. As shown in FIG. 1, the semiconductor device 1 according to this embodiment includes an imaging unit 10 that captures an image of a subject, a control unit 20 that controls the operation of the imaging unit 10, an imaging unit 10, and a control unit 20. And a connection substrate 30 for electrically connecting the two. In addition, the semiconductor device 1 includes a heat blocking structure 100 that blocks heat transfer between the imaging unit 10 and the control unit 20.

  The imaging unit 10 is a unit for acquiring an image of a subject, and as illustrated in FIG. 1, a solid-state imaging device 11 that captures an image of the subject, an imaging substrate 12 that mounts the solid-state imaging device 11, and the like, A cover glass 13 that protects the functional surface of the image sensor 11 and a surrounding rigid body 15 that surrounds the solid-state image sensor 11 on the imaging substrate 12 are provided.

  The solid-state imaging device 11 is a bare-chip semiconductor device (an example of an electronic component) realized by using a CCD or a CMOS image sensor, and has an imaging function of receiving light from a subject and capturing an image of the subject. Have Specifically, the solid-state imaging device 11 includes a light receiving function unit 11a having a light receiving surface that receives light from a subject and various circuits necessary for an imaging function on the surface of a substrate such as a silicon substrate, and the light receiving function unit. A plurality of protruding electrodes 11b fixed on electrode terminals electrically connected to 11a.

  The light receiving function unit 11a is realized using a plurality of pixels, a color filter, and the like that are two-dimensionally arranged. First, the light receiving function unit 11a receives light from a subject through an optical system including the cover glass 13, and performs photoelectric conversion processing on the received light. Next, the light receiving function unit 11a generates an image signal of the subject based on the signal obtained by the photoelectric conversion process.

  The plurality of protruding electrodes 11b are fixed to a plurality of electrode pads formed around the outside of the light receiving function unit 11a. Although not particularly illustrated, each of the plurality of protruding electrodes 11b fixed to the electrode pad in this manner is electrically connected to the light receiving function unit 11a via a circuit wiring or the like formed on the substrate of the solid-state imaging device 11. Connect to.

  Each of the plurality of protruding electrodes 11b may be a stud bump such as gold or copper formed by a wire bonding method, or a metal bump such as gold, silver, indium or solder formed by a plating method. There may be. Each of the plurality of protruding electrodes 11b may be a metal ball or a resin ball having a surface plated with metal.

  The solid-state imaging device 11 having the light receiving function portion 11a and the plurality of protruding electrodes 11b as described above is flip-chip mounted on the imaging substrate 12 using an adhesive 11c as shown in FIG. Accordingly, each of the plurality of protruding electrodes 11b is connected and fixed to an electrode terminal (not shown) of the imaging substrate 12. As a result, the solid-state imaging device 11 is electrically connected to the circuit wiring of the imaging substrate 12 through the plurality of protruding electrodes 11b. The image signal generated by the light receiving function unit 11a described above is output to the imaging substrate 12 side through the plurality of protruding electrodes 11b.

  Here, the adhesive 11c is for ensuring the electrical connection state between the solid-state imaging device 11 and the imaging substrate 12 described above, and the solid-state imaging device 11 and the imaging so as not to enter the light receiving function unit 11a side. The gap with the substrate 12 is filled. The adhesive 11c may be an epoxy, phenol, silicon, urethane or acrylic insulating adhesive, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP). An anisotropic conductive adhesive such as) may be used.

  The imaging board 12 is a circuit board on which a circuit for realizing the imaging function of the solid-state imaging device 11 and an opening 12a facing the light receiving function part 11a are formed. The imaging board 12 may be a flexible flexible circuit board that can be easily deformed by application of an external force, or may be a rigid circuit board that is less likely to be deformed than a flexible circuit board.

  The opening 12a has an opening size designed corresponding to the light receiving function unit 11a of the solid-state imaging device 11, that is, an opening size larger than a predetermined size with respect to the size of the light receiving function unit 11a. The light from the subject can be incident on 11a.

  As shown in FIG. 1, the solid-state imaging device 11 is flip-chip mounted on such an imaging substrate 12 with the light receiving function portion 11 a and the opening portion 12 a facing each other. In this case, the imaging substrate 12 is mounted with the solid-state imaging element 11 so as to close the opening 12 a with the solid-state imaging element 11. Furthermore, the surrounding rigid body 15 surrounding the mounted solid-state imaging device 11 is attached to the imaging substrate 12.

  Although not particularly shown on the imaging substrate 12, circuit wiring that is electrically connected to the solid-state imaging device 11, and a metal pattern for heat dissipation for releasing heat of the imaging substrate 12 (hereinafter referred to as a heat dissipation pattern) Is formed. The imaging substrate 12 is electrically connected to the connection substrate 30 through the electrode terminals of such circuit wiring. In addition, the imaging substrate 12 is connected to the connection substrate 30 through such a heat dissipation pattern so as to be able to conduct heat.

  The cover glass 13 is an optical member that is transparent to light from the subject, that is, light that should be received by the light receiving function unit 11a of the solid-state imaging device 11. As shown in FIG. 1, the cover glass 13 is fixed to the imaging substrate 12 with an adhesive 14 so as to close the opening 12 a of the imaging substrate 12 facing the light receiving function portion 11 a of the solid-state imaging device 11. The cover glass 13 attached to the imaging substrate 12 in this manner transmits light from the subject to the light receiving function unit 11a side of the solid-state imaging device 11, prevents foreign matter from entering the light receiving function unit 11a, and is caused by external force. The light receiving function unit 11a is protected from damage or the like.

  The surrounding rigid body 15 is a rigid body having a multilayer cross-sectional structure that surrounds the solid-state imaging device 11 on the imaging substrate 12. FIG. 2 is a schematic diagram showing an example of the outer shape of the surrounding rigid body and the multilayer cross-sectional structure. As shown in FIGS. 1 and 2, the surrounding rigid body 15 is formed by a rigid body 15 a having electromagnetic wave absorbability.

  The rigid body 15a is an electromagnetic wave absorbing member such as ferrite or carbon, and is formed in a hollow structure having a box-shaped outer shape with one end opened as shown in FIG. The opening end of the rigid body 15a, that is, the opening end of the surrounding rigid body 15 is fixed in the vicinity of the outer periphery of the solid-state imaging device 11 on the imaging substrate 12, as shown in FIG. The imaging substrate 12 and the surrounding rigid body 15 are fixed using an epoxy adhesive or a heat conductive adhesive. The surrounding rigid body 15 fixed to the imaging substrate 12 as described above surrounds the solid-state imaging device 11 on the imaging substrate 12 as shown in FIG. 1, and thereby, the solid-state imaging device 11 and the outside of the surrounding rigid body 15 are connected. Cut off.

  Here, the surrounding rigid body 15 has a multilayer cross-sectional structure including a layer of a rigid body 15a that absorbs electromagnetic waves, that is, an electromagnetic wave absorbing layer, and a decompression layer 15b that is decompressed compared to the outside air (the atmosphere outside the surrounding rigid body 15). . Specifically, the multilayer cross-sectional structure of the surrounding rigid body 15 is a three-layer cross-sectional structure in which the decompression layer 15b is sandwiched between two electromagnetic wave absorption layers, as shown in FIGS. In this three-layer cross-sectional structure, the rigid body 15a forms an outer layer of the surrounding rigid body 15, and the electromagnetic wave absorbing layer of the surrounding rigid body 15 is formed by the rigid body 15a that is the outer layer.

  On the other hand, the decompression layer 15b is a hollow layer sealed by the rigid body 15a described above, and is formed by decompressing compared to the outside air. Specifically, a vent hole (not shown) communicating with the outside air is formed in a part of the rigid body 15a, and the vacuum layer 15b is formed by degassing (depressurizing treatment) the hollow layer between the rigid bodies 15a through the vent hole. Is done. The vent hole of the rigid body 15a is closed by an electromagnetic wave absorbing member or the like after the decompression layer 15b is formed. The decompression layer 15b formed in this way may contain air as long as the decompression layer 15b is decompressed as compared with the outside air, but is preferably a vacuum.

  The control unit 20 is a unit for controlling the imaging unit 10, and as shown in FIG. 1, a DSP 21, another electronic component 22 such as a chip capacitor, and a control board 23 on which the DSP 21 and the electronic component 22 are mounted. Is provided. The DSP 21 is a semiconductor element (an example of an electronic component) that controls the operation of the solid-state imaging device 11 described above. A plurality of protruding electrodes are formed on the surface of a substrate such as a silicon substrate on which a circuit necessary for a control function is formed. 21a.

  The plurality of protruding electrodes 21a are fixed to a plurality of electrode pads formed on the substrate. Although not particularly illustrated, each of the plurality of protruding electrodes 21a fixed to the electrode pad in this manner is electrically connected to the circuit of the DSP 21 through a circuit wiring or the like formed on the substrate.

  Each of the plurality of protruding electrodes 21a may be a stud bump such as gold or copper formed by a wire bonding method, or may be a metal bump such as gold, silver, indium, or solder formed by a plating method. There may be. Each of the plurality of protruding electrodes 21a may be a metal ball or a resin ball having a surface plated with metal.

  The DSP 21 having such a configuration is flip-chip mounted on the control board 23 using an adhesive 21b as shown in FIG. Thereby, each of the plurality of protruding electrodes 21 a is connected and fixed to an electrode terminal (not shown) of the control board 23. As a result, the DSP 21 is electrically connected to the circuit wiring of the control board 23 through the plurality of protruding electrodes 21a. A control signal for the DSP 21 to control the solid-state imaging device 11 is output to the control board 23 side through the plurality of protruding electrodes 21a.

  On the other hand, the electronic component 22 is an electronic component such as a chip capacitor, and is mounted on the electrode terminal of the control board 23 as necessary for the DSP 21 to operate normally. The electronic component 22 and the control board 23 are fixed using an adhesive 22a.

  Here, the adhesive 21b is for ensuring an electrical connection state between the DSP 21 and the control board 23, and the adhesive 22a is an electrical connection state between the electronic component 22 and the control board 23. Is to do. The adhesives 21b and 22a may be an epoxy, phenol, silicon, urethane or acrylic insulating adhesive, or an anisotropic conductive adhesive such as ACF or ACP. Also good.

  The control board 23 is a circuit board on which a circuit necessary for realizing the control function of the DSP 21 is formed. As shown in FIG. 1, the DSP 21 is flip-chip mounted on the control board 23, and the electronic component 22 is further mounted. The control board 23 may be a flexible flexible circuit board that can be easily deformed by application of an external force, or may be a rigid circuit board that is less likely to be deformed than a flexible circuit board.

  The control board 23 is formed with circuit wiring that is electrically connected to the DSP 21 and a heat radiation pattern for releasing the heat of the control board 23, although not particularly shown. The control board 23 is electrically connected to the connection board 30 through the electrode terminals of such circuit wiring. Further, the control board 23 is connected to the connection board 30 through such a heat dissipation pattern so as to be able to conduct heat.

  The connection board 30 is a flexible flexible circuit board that can be easily deformed by applying external force, and connects the imaging board 12 and the control board 23 described above. Specifically, the connection board 30 includes an imaging board side electrode terminal electrically connected to the imaging board 12 and a control board side electrode terminal electrically connected to the control board 23. The connection board 30 is formed with a circuit for electrically connecting the imaging board side electrode terminals and the control board side electrode terminals.

  Further, the connection board 30 has a heat radiation pattern that conducts heat from the imaging board 12 and a heat radiation pattern that conducts heat from the control board 23. The connection board 30 is connected to the imaging board 12 and the control board 23 through such a heat radiation pattern.

  The imaging board 12 and the control board 23 are electrically and thermally connected to the connection board 30 having such a configuration. That is, the imaging board 12 and the control board 23 are electrically connected via the connection board 30 and are connected to the connection board 30 so as to be capable of conducting heat. In addition, the imaging board 12 and the control board 23 connected via the flexible connection board 30 are positioned in the vicinity of each other in an opposing manner as shown in FIG.

  On the other hand, as shown in FIG. The heat absorber 31 absorbs heat conducted to the connection substrate 30. Specifically, the heat absorber 31 is formed of a metal or alloy having high heat dissipation such as copper or aluminum, and is fixed to a predetermined position (for example, on the heat dissipation pattern) of the connection substrate 30. The heat absorber 31 on the connection board 30 absorbs heat conducted from the imaging board 12 side to the connection board 30 and heat conducted from the control board 23 side to the connection board 30 and releases the absorbed heat to the outside. Thus, the heat absorber 31 blocks heat conduction between the imaging substrate 12 and the control substrate 23 via the connection substrate 30. Specifically, the heat absorber 31 blocks heat conduction between the solid-state imaging device 11 and the DSP 21 via the connection substrate 30.

  Here, the surrounding rigid body 15 and the heat absorbing body 31 described above constitute the heat blocking structure 100 of the semiconductor device 1. Specifically, the surrounding rigid body 15 blocks heat radiation between the solid-state imaging element 11 and the DSP 21 by the action of the rigid body 15a that is an electromagnetic wave absorbing member, and the solid-state imaging element 11 and the DSP 21 by the action of the decompression layer 15b. Block heat convection between On the other hand, the heat absorber 31 blocks heat conduction between the solid-state imaging device 11 and the DSP 21 via the connection substrate 30 as described above. The heat blocking structure 100 having the surrounding rigid body 15 and the heat absorbing body 31 blocks all heat transfer (thermal radiation, heat convection, heat conduction) between the solid-state imaging device 11 and the DSP 21.

  The semiconductor device 1 having the above-described configuration includes various types of electronic devices such as a digital camera and a digital video camera, an endoscope for observing the inside of an organ of a subject, and a mobile phone having an imaging function. It can be applied as an imaging unit of an imaging device.

  Next, the operation of the heat blocking structure 100 according to the embodiment of the present invention will be described. FIG. 3 is a schematic diagram for explaining the operation of the heat shielding structure according to the embodiment of the present invention. In FIG. 3, the wavy arrow indicates the flow of thermal energy due to thermal radiation, the alternate long and short dash line indicates the flow of thermal energy due to thermal convection, and the dashed arrow indicates the flow of thermal energy due to heat conduction.

  First, the case where the DSP 21 is a heat generation source will be described as an example to explain the operation of the heat blocking structure 100. The DSP 21 generates heat each time it operates to control the solid-state imaging device 11, and the generated heat energy is transmitted from the DSP 21 by heat radiation, heat convection, and heat conduction.

  The thermal energy radiated by the DSP 21, that is, the thermal energy by the thermal radiation, is emitted radially from the DSP 21 as indicated by a wavy arrow in FIG. 3, and thereafter, the surrounding rigid body 15 that is one of the heat blocking structures 100. To reach.

  Here, the thermal energy by thermal radiation is emitted as electromagnetic waves. 3 is absorbed by the rigid body 15a which is the electromagnetic wave absorbing layer of the surrounding rigid body 15. For this reason, the thermal energy generated by the thermal radiation from the DSP 21 is not transmitted to the solid-state imaging device 11 surrounded by the rigid body 15a. As a result, the thermal radiation from the DSP 21 to the solid-state imaging device 11 is blocked by the surrounding rigid body 15. The The thermal energy absorbed by the rigid body 15a is conducted to the connection substrate 30 through the heat radiation pattern of the imaging substrate 12.

  On the other hand, the thermal energy transmitted by the convection of the air in contact with the DSP 21, that is, the thermal energy by the thermal convection is transmitted from the DSP 21 along with the convection of the air in the vicinity of the DSP 21 as shown by the one-dot chain arrow in FIG. The surrounding rigid body 15 that is one of the blocking structures 100 is reached.

  Here, the depressurization layer 15b of the surrounding rigid body 15 is a hollow layer depressurized compared to the outside air as described above, and is close to a vacuum state. Accordingly, air convection hardly occurs in the decompression layer 15b, and thus, thermal energy due to thermal convection is not transmitted to the inside of the decompression layer 15b. Note that air convection inside the decompression layer 15b is less likely to occur as the pressure in the decompression layer 15b is lower. Furthermore, when the decompression layer 15b is in a vacuum state, air convection does not occur inside the decompression layer 15b.

  For this reason, thermal energy from the thermal convection from the DSP 21 is not transmitted to the solid-state imaging device 11 surrounded by the decompression layer 15b, and as a result, thermal convection from the DSP 21 to the solid-state imaging device 11 is blocked by the surrounding rigid body 15. Is done. The thermal energy blocked by the decompression layer 15b is conducted to the connection substrate 30 through the rigid body 15a and the heat radiation pattern of the imaging substrate 12.

  On the other hand, thermal energy conducted from the DSP 21 to the control board 23, that is, thermal energy by thermal conduction, is conducted from the control board 23 to the connection board 30 as shown by a broken line arrow in FIG. Reaches the endothermic body 31.

  Here, as shown in FIG. 3, the heat absorber 31 is fixed to a housing 40 of an electronic imaging device incorporating the semiconductor device 1. The heat absorber 31 in this state absorbs the thermal energy conducted from the control board 23 to the connection board 30, and then conducts the absorbed thermal energy to the housing 40. Therefore, heat energy by heat conduction is not conducted from the heat absorber 31 to the imaging substrate 12 side.

  For this reason, thermal energy from the heat conduction from the DSP 21 is not transmitted to the solid-state imaging device 11 located on the imaging substrate 12 side with the endothermic body 31 as a boundary. As a result, heat conduction from the DSP 21 to the solid-state imaging device 11 is It is blocked by the heat absorber 31. The thermal energy blocked by the heat absorber 31 is transmitted to the housing 40 and then released to the outside of the electronic imaging device.

  As described above, the heat blocking structure 100 blocks all heat radiation, heat convection, and heat conduction from the DSP 21 to the solid-state imaging device 11. For this reason, the thermal energy generated in the DSP 21 is not transmitted to the solid-state imaging device 11, and as a result, the temperature rise of the solid-state imaging device 11 due to the heat generated by the DSP 21 can be reduced.

  Next, the case where the solid-state imaging device 11 is a heat generation source will be described as an example, and the operation of the heat blocking structure 100 will be described. The solid-state image sensor 11 generates heat each time it operates based on the control of the DSP 21, and the generated heat energy is transmitted from the solid-state image sensor 11 by heat radiation, heat convection, and heat conduction.

  The thermal energy radiated by the solid-state imaging device 11, that is, the thermal energy by thermal radiation, is emitted radially from the solid-state imaging device 11 and then reaches the surrounding rigid body 15 as indicated by the wavy arrow in FIG. 3. .

  Here, since the thermal energy generated by the thermal radiation from the solid-state imaging device 11 is the thermal energy emitted as an electromagnetic wave, it is absorbed by the rigid body 15 a that is the electromagnetic wave absorbing layer of the surrounding rigid body 15. For this reason, the thermal energy generated by the thermal radiation from the solid-state imaging device 11 is not transmitted to the DSP 21 located outside the rigid body 15a. As a result, the thermal radiation from the solid-state imaging device 11 to the DSP 21 is blocked by the surrounding rigid body 15. . The thermal energy absorbed by the rigid body 15a is conducted to the connection substrate 30 through the heat radiation pattern of the imaging substrate 12 as in the case where the DSP 21 is a heat source.

  On the other hand, the thermal energy transmitted by the convection of the air in contact with the solid-state image sensor 11, that is, the thermal energy by the thermal convection, is shown in FIG. It is transmitted from the element 11 and then reaches the surrounding rigid body 15.

  Here, as described above, the convection of air inside the decompression layer 15b of the surrounding rigid body 15 is less likely to occur as the pressure of the decompression layer 15b is lower. Furthermore, when the decompression layer 15b is in a vacuum state, the decompression layer 15b There is no air convection inside. Therefore, the thermal energy by thermal convection is not transmitted to the inside of the decompression layer 15b.

  For this reason, thermal energy from thermal convection from the solid-state imaging device 11 is not transmitted to the DSP 21 located outside the decompression layer 15b, and as a result, thermal convection from the solid-state imaging device 11 to the DSP 21 is blocked by the surrounding rigid body 15. The The thermal energy blocked by the decompression layer 15b is conducted to the connection substrate 30 through the rigid body 15a and the heat radiation pattern of the imaging substrate 12 as in the case where the DSP 21 is a heat generation source.

  On the other hand, thermal energy conducted from the solid-state imaging device 11 to the imaging substrate 12, that is, thermal energy due to thermal conduction, is conducted from the imaging substrate 12 to the connection substrate 30 as shown by a broken line arrow in FIG. To reach.

  Here, the heat absorber 31 is in a state of being fixed to the housing 40 as described above. The heat absorber 31 in this state absorbs the thermal energy conducted from the imaging substrate 12 to the connection substrate 30, and then conducts the absorbed thermal energy to the housing 40. Therefore, the heat energy by heat conduction is not conducted from the heat absorber 31 to the control board 23 side.

  For this reason, the heat energy from the heat conduction from the solid-state image sensor 11 is not transmitted to the DSP 21 located on the control board 23 side with the heat absorber 31 as a boundary. As a result, the heat conduction from the solid-state image sensor 11 to the DSP 21 is It is blocked by the heat absorber 31. Note that the thermal energy blocked by the heat absorber 31 is released to the outside of the electronic imaging apparatus via the housing 40, as in the case where the DSP 21 is a heat source.

  As described above, the heat blocking structure 100 blocks all heat radiation, heat convection, and heat conduction from the solid-state imaging device 11 to the DSP 21. For this reason, the thermal energy generated in the solid-state imaging device 11 is not transmitted to the DSP 21, and as a result, the temperature rise of the DSP 21 due to heat generation of the solid-state imaging device 11 can be reduced.

  As described above, in the embodiment of the present invention, the first electronic component on the first circuit board is surrounded by the surrounding rigid body having the multilayer cross-sectional structure having the electromagnetic wave absorbing layer and the hollow decompression layer. The second electronic component and the first electronic component on the second circuit board located outside the surrounding rigid body are separated from each other by the surrounding rigid body. For this reason, thermal energy by thermal radiation can be absorbed by the electromagnetic wave absorbing layer of the surrounding rigid body, and furthermore, thermal convection can be suppressed by the decompression layer of the surrounding rigid body, whereby heat between the first electronic component and the second electronic component can be suppressed. Radiation and thermal convection can be blocked. As a result, the mutual heat interference between the first electronic component and the second electronic component can be suppressed, and the temperature rise of the first electronic component and the second electronic component can be reduced, thereby the first due to the temperature rise. The functional deterioration of the electronic component and the second electronic component can be prevented.

  Further, in the embodiment of the present invention, a heat absorber is disposed on the connection board that connects the first circuit board and the second circuit board, and the heat conducted to the connection board is absorbed by the heat absorber. Configured. For this reason, the heat conducted from the first circuit board side to the connection board and the heat conducted from the second circuit board side to the connection board can both be absorbed and released to the outside of the apparatus. The heat conduction between the first electronic component and the second electronic component can be blocked. As a result, the mutual thermal interference between the first electronic component and the second electronic component connected via the circuit board is suppressed, and the temperature rise of the first electronic component and the second electronic component is reduced. Thus, it is possible to prevent the first electronic component and the second electronic component from deteriorating due to temperature rise.

  Furthermore, the connection board having flexibility is curved, and the first circuit board and the second circuit board are arranged to face each other. For this reason, the first circuit board and the second circuit board can be arranged at high density inside the apparatus housing, and thereby the first electronic component can be achieved without hindering downsizing of the apparatus housing. The heat transfer between the second electronic component and the second electronic component can be blocked.

  By applying the heat blocking structure according to the embodiment of the present invention to the semiconductor device in the electronic imaging device, heat transfer between the solid-state imaging device and the DSP in the semiconductor device can be blocked. For this reason, it is possible to suppress the mutual thermal interference between the solid-state imaging device and the DSP and reduce the temperature rise of the solid-state imaging device and the DSP. As a result, the solid-state imaging device and the DSP are degraded due to the temperature rise. Can be prevented together.

(Modification)
Next, a modification of the embodiment of the present invention will be described. In the embodiment described above, the solid-state imaging device 11 is surrounded by the surrounding rigid body 15. However, in this modification, the DSP 21 on the control board 23 and the surrounding rigid body having the same multilayer structure as the surrounding rigid body 15 are used. The electronic component 22 is further surrounded.

  FIG. 4 is a schematic cross-sectional view showing a configuration example of a semiconductor device provided with a heat blocking structure according to a modification of the embodiment of the present invention. As shown in FIG. 4, the semiconductor device 2 according to this modification includes a heat blocking structure 200 instead of the heat blocking structure 100 of the semiconductor device 1 according to the above-described embodiment. In addition to the surrounding rigid body 15 and the heat absorbing body 31 described above, the heat blocking structure 200 is configured by further including an surrounding rigid body 25 that surrounds the DSP 21 and the electronic component 22 on the control board 23. Other configurations are the same as those of the above-described embodiment, and the same reference numerals are given to the same components.

  The surrounding rigid body 25 is a rigid body having a multilayer cross-sectional structure that surrounds the DSP 21 and the electronic component 22 on the control board 23. Specifically, the surrounding rigid body 25 has a multilayer cross-sectional structure similar to that of the surrounding rigid body 15 in the above-described embodiment, and is formed by a rigid body 25a having electromagnetic wave absorbability as shown in FIG.

  The rigid body 25a is an electromagnetic wave absorbing member such as ferrite or carbon, and is formed into a hollow structure having a box-shaped outer shape with one end opened. The open end of the rigid body 25a, that is, the open end of the surrounding rigid body 25 is fixed near the outside of the component mounting area (the mounting area of the DSP 21 and the electronic component 22) on the control board 23, as shown in FIG. The The control board 23 and the surrounding rigid body 25 are fixed using an epoxy adhesive or a heat conductive adhesive.

  The surrounding rigid body 25 fixed to the control board 23 as described above surrounds the DSP 21 and the electronic component 22 on the control board 23 as shown in FIG. And shut off.

  Here, the surrounding rigid body 25 has a multilayer cross-sectional structure including a layer of a rigid body 25a that absorbs electromagnetic waves, that is, an electromagnetic wave absorbing layer, and a reduced pressure layer 25b that is decompressed compared to the outside air (the external atmosphere of the surrounding rigid body 25). . Specifically, the multilayer cross-sectional structure of the surrounding rigid body 25 is a three-layer cross-sectional structure in which the decompression layer 25b is sandwiched between two electromagnetic wave absorption layers, as shown in FIG. In this three-layer cross-sectional structure, the rigid body 25a forms an outer layer of the surrounding rigid body 25, and the electromagnetic wave absorbing layer of the surrounding rigid body 25 is formed by the rigid body 25a that is the outer layer.

  On the other hand, the decompression layer 25b is a hollow layer sealed by the rigid body 25a described above, and is formed by decompressing compared to the outside air. Specifically, a vent hole (not shown) that communicates with the outside air is formed in a part of the rigid body 25a, and the hollow layer between the rigid bodies 25a is degassed (depressurized) through the vent hole to form the decompressed layer 25b. Is done. The vent hole of the rigid body 25a is closed by an electromagnetic wave absorbing member or the like after the decompression layer 25b is formed. The decompression layer 25b formed in this way may contain air as long as the decompression layer 25b is decompressed as compared with the outside air, but is preferably a vacuum.

  Here, the surrounding rigid bodies 15 and 25 and the heat absorbing body 31 described above constitute the heat blocking structure 200 of the semiconductor device 2. The heat blocking action of the surrounding rigid body 15 and the endothermic body 31 is the same as that in the above-described embodiment.

  The surrounding rigid body 25 blocks heat radiation between the solid-state imaging device 11 and the DSP 21 by the action of the rigid body 25a that is an electromagnetic wave absorbing member, and heat between the solid-state imaging element 11 and the DSP 21 by the action of the decompression layer 25b. Block convection. Specifically, the surrounding rigid body 25 blocks heat radiation and heat convection from the outside of the surrounding rigid body 25 to the DSP 21 and blocks heat radiation and heat convection from the DSP 21 to the outside of the surrounding rigid body 25. Note that the heat blocking action of the surrounding rigid body 25 on the DSP 21 is the same as the heat blocking action of the surrounding rigid body 15 on the solid-state imaging device 11 described above.

  The heat blocking structure 200 having the surrounding rigid bodies 15 and 25 and the heat absorbing body 31 as described above is added with the heat blocking action of the surrounding rigid body 25, so that the solid-state imaging device 11 is compared with the above-described embodiment. All heat transfer (heat radiation, heat convection, heat conduction) between the device and the DSP 21 is cut off more efficiently.

  The semiconductor device 2 having the above-described configuration is an endoscope for observing the inside of an organ of a subject, including a digital camera and a digital video camera, like the semiconductor device 1 in the above-described embodiment. The present invention can be applied as an imaging unit of various types of electronic imaging devices such as a mobile phone having an imaging function.

  As described above, in the modification of the embodiment of the present invention, the second envelope on the second circuit board is provided by another surrounding rigid body having a multilayer cross-sectional structure having an electromagnetic wave absorption layer and a hollow decompression layer. The electronic component is further surrounded, and the others are configured in the same manner as in the embodiment. Therefore, the added surrounding rigid body can block heat radiation and heat convection from the second electronic component to the first electronic component, and can also prevent heat radiation and heat convection from the first electronic component to the second electronic component. It can be blocked more efficiently. As a result, the mutual thermal interference between the first electronic component and the second electronic component can be further suppressed, and the temperature increase of the first electronic component and the second electronic component can be further reduced, thereby causing the temperature increase. It is possible to efficiently prevent functional degradation of the first electronic component and the second electronic component.

  By applying the heat blocking structure according to the modification of the embodiment of the present invention to the semiconductor device in the electronic imaging device, the heat transfer between the solid-state imaging device and the DSP in the semiconductor device is more efficiently blocked. can do. For this reason, the mutual thermal interference between the solid-state imaging device and the DSP can be further suppressed, and the temperature rise of the solid-state imaging device and the DSP can be efficiently reduced. It is possible to efficiently prevent both DSP functions from being degraded.

  In the above-described embodiment and modification, the surrounding rigid body having a three-layer cross-sectional structure in which the reduced pressure layer is sandwiched by the electromagnetic wave absorption layer is illustrated, but the invention is not limited to this and is one of the heat shielding structures in the present invention. The multi-layered cross-sectional structure of the surrounding rigid body is sufficient if it has at least an electromagnetic wave absorption layer and a reduced pressure layer (preferably a vacuum layer), and may be a surrounding rigid body having a cross-sectional structure of four or more layers. In this case, for example, a heat insulating layer formed by a heat insulating member may be added.

  In the embodiment and the modification described above, the surrounding rigid body is formed by the rigid body made of the electromagnetic wave absorbing member. However, the rigid body forming the surrounding rigid body is not limited to this, and the rigid body having low electromagnetic wave absorption (resin, It may have an electromagnetic wave absorbing layer formed of electromagnetic wave absorbing particles or electromagnetic wave absorbing paint on the surface of a metal or the like or a heat insulating member.

  Furthermore, in the above-described embodiment and modification, one or two electronic components (including a semiconductor element) are surrounded by one surrounding rigid body. However, the present invention is not limited to this, and three or more are surrounded by one surrounding rigid body. The electronic component may be surrounded. In particular, three or more semiconductor elements may be surrounded by one surrounding rigid body.

  In the embodiment and the modification described above, the heat absorber 31 that is one of the heat blocking structures is arranged on the connection board 30. However, the present invention is not limited to this, and the connection between the electronic components to be heat blocked is between the connection boards 30. If the heat absorber 31 is not connected, the heat absorber 31 may not be provided.

  Furthermore, in the above-described embodiment and modification, the solid-state imaging element or the DSP is surrounded by the surrounding rigid body. However, the semiconductor element surrounded by the surrounding rigid body is not limited to this, but is a semiconductor element other than the solid-state imaging element. It may be a semiconductor element other than a DSP. That is, the semiconductor device provided with the heat blocking structure according to the present invention is not limited to the one built in the electronic imaging device.

  In the embodiment and the modification described above, the cross-sectional shape of the surrounding rigid body is a U-shape or a polygonal shape. However, the cross-sectional shape of the surrounding rigid body may be a rectangular shape. The shape may be circular or elliptical. That is, a surrounding rigid body having a desired cross-sectional shape may be used in accordance with the electronic component surrounded by the surrounding rigid body.

  As described above, the heat shut-off structure according to the present invention is useful for heat shut-off between electronic components, and in particular, it can block heat transfer between electronic components and prevent deterioration of the function of the electronic components due to temperature rise. Suitable for heat shield structure.

DESCRIPTION OF SYMBOLS 1, 2 Semiconductor device 10 Image pick-up part 11 Solid-state image pick-up element 11a Light receiving function part 11b Projection electrode 11c Adhesive agent 12 Imaging board 12a Opening part 13 Cover glass 14 Adhesive 15, 25 Surrounding rigid body 15a, 25a Rigid body 15b, 25b Decompression layer 20 Control Part 21 DSP
21a Protruding electrode 21b Adhesive 22 Electronic component 22a Adhesive 23 Control board 30 Connection board 31 Endothermic body 100, 200 Heat blocking structure

Claims (6)

It has a multilayer cross-sectional structure having an electromagnetic wave absorbing layer that absorbs electromagnetic waves and a reduced pressure layer that is depressurized compared to the outside air, and includes a surrounding rigid body that surrounds the first electronic component on the first circuit board,
A heat shut-off structure that cuts off heat transfer between a second electronic component on a second circuit board disposed outside the surrounding rigid body and the first electronic component.   The heat sink which is arrange | positioned at the connection board | substrate which connects the said 1st circuit board and the said 2nd circuit board, and absorbs the heat | fever conducted by the said connection board | substrate is further provided. Heat insulation structure. The electromagnetic wave absorbing layer is an outer layer of the surrounding rigid body,
The heat insulation structure according to claim 1 or 2, wherein the decompression layer is hermetically sealed by the outer layer.   The heat shielding structure according to any one of claims 1 to 3, wherein the surrounding rigid body is formed by an electromagnetic wave absorbing member that forms the electromagnetic wave absorbing layer and seals the reduced pressure layer.   The heat blocking structure according to any one of claims 1 to 4, wherein the decompression layer is a vacuum layer.   2. A multi-layer cross-sectional structure having an electromagnetic wave absorbing layer that absorbs electromagnetic waves and a reduced pressure layer that is depressurized compared to outside air, and further comprising another surrounding rigid body that surrounds the second electronic component. Item 6. The heat shielding structure according to any one of Items 1 to 5.

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