Electronic apparatus

Abstract

To provide an electronic apparatus that is easy to disassemble, for example, for repair, while ensuring sufficient thermal conductivity for transferring heat from a heating element to a cooling duct.SOLUTION: An imaging apparatus 100, which is an electronic apparatus, includes a control circuit board 501 having at least one heating element 610 that generates heat through energization, a forced air-cooling duct 505 that is arranged opposite the control circuit board 501 and through which air passes to cool the heating element 610, a heat-dissipating gap filler 504 that is provided on the surface of the forced air-cooling duct 505 which faces the control circuit board 501 and that transfers heat from the heating element 610 to the forced air-cooling duct 505, a film 503 that is provided between the control circuit board 501 and the heat-dissipating gap filler 504, and positioning means 800 that positions the film 503 at a position where contact between the control circuit board 501 and the heat-dissipating gap filler 504 can be prevented.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] In recent imaging devices, image quality has been improving due to, for example, higher resolution and higher frame rates of recorded images. In such imaging devices, the processing load on electronic components such as IC chips mounted on a control circuit board increases as image quality improves, resulting in significant heat generation from the electronic components. Heat generated by electronic components can cause performance degradation or malfunction of the imaging device, so a cooling structure is provided to cool the electronic components. Liquid heat dissipation materials, such as thermal grease or thermally conductive grease, are sometimes used as cooling structures (see, for example, Patent Documents 1 and 2). Liquid heat dissipation materials generally have superior capabilities in reducing contact thermal resistance generated at the contact surfaces between components compared to solid heat dissipation materials such as heat dissipation sheets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-115417 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-77569 Summary of the Invention [Problem to be solved by the invention]

[0004] However, both Patent Documents 1 and 2 use grease as the liquid heat dissipation material, which can lead to problems such as leakage or adhesion to gloves or work clothes during assembly or disassembly, depending on the worker's level of skill. In some cases, heat dissipation gap fillers are used instead of grease. A "heat dissipation gap filler" is a paste-like substance containing a thermally conductive filler. It is applied to a predetermined location as a cooling structure and hardens over time. Once hardened, the heat dissipation gap filler has extremely strong adhesive strength to the predetermined location. Therefore, during disassembly, for example, it becomes difficult to peel the hardened heat dissipation gap filler from the predetermined location, resulting in reduced workability.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide an electronic device that is easy to disassemble for repairs, for example, while ensuring sufficient thermal conductivity for transferring heat from a heat-generating body to a cooling duct. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the electronic device of the present invention is characterized by comprising: a circuit board having at least one heat-generating element that generates heat when current is applied; a cooling duct arranged opposite the circuit board and through which air passes to cool the heat-generating element; a heat-dissipating filler that is arranged in contact with the surface of the cooling duct facing the circuit board and has thermal conductivity to transfer heat from the heat-generating element to the cooling duct; a flexible member that is arranged between the circuit board and the heat-dissipating filler; and positioning means that positions the flexible member in a position that prevents contact between the circuit board and the heat-dissipating filler. [Effects of the Invention]

[0007] According to the present invention, the thermal conductivity for transferring heat from the heat generating element to the cooling duct is sufficiently ensured, while the ease of disassembly during repairs, for example, is excellent. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of the appearance of an imaging device to which the electronic device according to the first embodiment is applied, as viewed from above and in front thereof. [Figure 2] 1 is an external perspective view of an imaging device to which the electronic device according to the first embodiment is applied, viewed from above and behind. [Figure 3] FIG. 2 is an exploded perspective view showing the internal configuration of the imaging device. [Figure 4] FIG. 2 is a plan view of the forced air-cooling structure in the internal structure. [Figure 5] FIG. 2 is a plan view of the forced air-cooling structure in the internal structure. [Figure 6] FIG. 2 is an exploded perspective view of a main unit of the imaging device. [Figure 7] FIG. 2 is a plan view of a control circuit board. [Figure 8] FIG. 2 is a diagram showing the positional relationship of a control circuit board, a film, a heat dissipation gap filler, and a forced air cooling duct in an assembled state. [Figure 9] FIG. 2 is a front view of the film and the forced air cooling duct as viewed from the front side of the imaging device. [Figure 10] FIG. 2 is a rear view of the control circuit board and the film as viewed from the rear side of the imaging device. [Figure 11] 10 is a front view of a forced air-cooling duct of an imaging device to which an electronic device according to a second embodiment is applied, as viewed from the front side of the imaging device. FIG. [Figure 12] FIG. 2 is a diagram showing the positional relationship of a control circuit board, a film, a heat dissipation gap filler, and a forced air cooling duct in an assembled state. [Figure 13] 11 is a front view of a forced air-cooling duct of an imaging device to which an electronic device according to a third embodiment is applied, as viewed from the front side of the imaging device. FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line BB in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment of the present invention will be described in detail below with reference to the drawings. However, the configurations described in each of the following embodiments are merely examples, and the scope of the present invention is not limited to the configurations described in each embodiment. For example, each component constituting the present invention can be replaced with any configuration that can perform the same function. Also, any component may be added. Furthermore, any two or more configurations (features) of each embodiment can be combined.

[0010] <<First Embodiment>> The first embodiment will be described below with reference to FIGS.

[0011] <External configuration of the imaging device> FIG. 1 is a perspective view of an imaging device incorporating an electronic device according to a first embodiment, as viewed from above and in front. FIG. 2 is a perspective view of an imaging device incorporating an electronic device according to a first embodiment, as viewed from above and in back. As shown in FIGS. 1 and 2, in this embodiment, mutually orthogonal X-, Y-, and Z-axes are set (the same applies to FIG. 3 and subsequent drawings). The Z-axis is set parallel to the front-rear direction of the imaging device 100, i.e., perpendicular to the imaging surface 101. The Z-axis is set as a positive direction from the rear side to the front side of the imaging device 100, and the opposite direction is set as a negative direction. The Y-axis is set parallel to the up-down direction of the imaging device 100. The Y-axis is set as a positive direction from the bottom side to the top side of the imaging device 100, and the opposite direction is set as a negative direction. The X-axis is set parallel to the left-right direction of the imaging device 100. The X-axis is set as a positive direction from the left side to the right side of the imaging device 100 when viewed from the front, and the opposite direction is set as a negative direction. The imaging device 100 has an imaging function for capturing moving images and still images, and is a device to which the electronic device of the present invention is applied.

[0012] As shown in FIG. 1, the imaging device 100 has a lens mount 102 provided on the front surface and an imaging surface 101 provided on the negative side of the lens mount 102 in the Z-axis direction, i.e., on the back side of the lens mount 102. A lens barrel (not shown) having multiple lenses with different optical performances is detachably attached to the lens mount 102. When attached to the lens mount 102, the lens barrel is communicably connected to the imaging device 100, thereby enabling the lenses to be driven. When attached to the lens mount 102, the lens barrel forms an image on the imaging surface 101 by the lenses. The imaging surface 101 generates video data based on the optical image formed on the imaging surface 101. The imaging device 100 also has an operation member 103 provided on the right side and an accessory mounting electrical contact 104 provided on the top surface. The operation member 103 is composed of, for example, multiple buttons, dials, etc. By operating the operation member 103, for example, it is possible to turn the power of the imaging device 100 on / off, start / stop imaging, adjust the image and sound, etc. The accessory mounting electrical contact 104 communicatively connects the imaging device 100 to an external accessory detachably attached to the upper side of the imaging device 100. This makes it possible to control the external accessory. The external accessory is not particularly limited and examples thereof include a microphone, a lighting device, a handle, etc. As shown in FIG. 2, the imaging device 100 has a general-purpose accessory mounting portion 105 and a speaker 106 provided on the rear surface. A general-purpose accessory can be attached to the general-purpose accessory mounting portion 105. The general-purpose accessory is not particularly limited and examples thereof include a tripod, etc. The speaker 106 emits, for example, sound from a video.

[0013] <Internal configuration of the imaging device> FIG. 3 is an exploded perspective view showing the internal configuration of the imaging device. As shown in FIG. 3, the imaging device 100 has an internal structure 300. The internal structure 300 includes an imaging element 310, a sensor duct unit 520, a control circuit board (circuit board) 501, a forced air-cooling duct (cooling duct) 505, a power supply board 350, and a cooling fan (fan) 506. The internal structure 300 also includes a media duct unit 380, a media board 390, a sub-media board 400, and a wireless board 312. These components constituting the internal structure 300 are arranged along the optical axis, i.e., the Z-axis direction, from the positive side to the negative side. Adjacent components in the Z-axis direction are arranged opposite each other. The imaging element 310 has an imaging surface 101 that converts light transmitted through each lens into an electrical signal. The control circuit board 501 is a board that controls the entire imaging device 100. The control circuit board 501 is the board with the largest area within the internal structure 300 and has multiple elements mounted thereon. The elements implemented on the control circuit board 501 are not particularly limited and may include, for example, elements for processing signals from the image sensor 310, elements for performing processes such as color adjustment of images, and memory used for these elements. The power supply board 350, together with the control circuit board 501, constitutes a power supply circuit that supplies power to each electrical component within the image capture device 100. The media board 390 is a board for recording the main image to a recording medium. The sub-media board 400 is a board for saving the imaging condition settings and recording backup images with a reduced data capacity of the main image recorded on the media board 390. The media duct unit 380 has an opening 382 penetrating in the Z-axis direction. At least a portion of the media board 390 is exposed through the opening 382. The wireless board 312 is electrically connected to the wireless antenna 311 and controls wireless communication with external devices. The wireless antenna 311 is located at the rear upper portion of the internal structure 300.

[0014] <Forced air cooling structure in the internal structure> 4 and 5 are plan views of the forced air-cooling structure in the internal structure. Note that FIG. 4 is a plan view of the forced air-cooling structure in the internal structure as viewed from the positive side in the Y-axis direction. FIG. 5(a) is a plan view of the forced air-cooling structure in the internal structure as viewed from the negative side in the Z-axis direction. FIG. 5(b) is a cross-sectional view taken along line AA in FIG. 5(a). As shown in FIG. 4, the forced air-cooling structure of the internal structure 300 includes a heat dissipation duct 301 and a cooling fan 506. As described above, multiple elements are mounted on the control circuit board 501. These elements are heat-generating elements (heat generating elements 610, described later) that generate heat when energized. The forced air-cooling structure is configured to dissipate heat from each element, i.e., each heat-generating element. Note that, although multiple elements are mounted on the control circuit board 501 in this embodiment, the number of elements is not limited thereto and may be at least one. In this embodiment, the elements are provided on the surface of control circuit board 501 facing forced air-cooling duct 505 (surface 501a described below), i.e., the surface facing the negative side in the Z axis direction, but this is not limiting. For example, the elements may be provided on the surface facing the positive side in the Z axis direction of control circuit board 501, or may be provided separately on the surface facing the positive side and the negative side in the Z axis direction of control circuit board 501. Heat dissipation duct 301 is made up of sensor duct unit 520, forced air-cooling duct 505, media duct unit 380, and exhaust duct unit 370.

[0015] The sensor duct unit 520 has a sensor duct intake port 521 that opens to the negative side in the X-axis direction. Air (outside air) AR is drawn into the sensor duct intake port 521. The sensor duct unit 520 is also connected to the forced air-cooling duct 505 via a sensor duct connection portion 542. This allows the sensor duct unit 520 and the forced air-cooling duct 505 to communicate with each other, and therefore air AR1 drawn into the sensor duct intake port 521 can pass through the sensor duct unit 520 and the forced air-cooling duct 505 in that order. Heat generated by the imaging element 310 is transferred to the sensor duct unit 520 via a heat-conducting member (not shown), such as a graphite sheet. This heat is then cooled as the air AR1 passes through the sensor duct unit 520.

[0016] As shown in FIG. 5(b), the media duct unit 380 has a media duct intake port 581 that opens on the positive side in the X-axis direction. Air AR2 is drawn in through the media duct intake port 581. The media duct unit 380 is also connected to the forced-air-cooling duct 505 via the media duct connection portion 543. This allows the media duct unit 380 and the forced-air-cooling duct 505 to communicate with each other, allowing the air AR2 drawn in through the media duct intake port 581 to pass through the media duct unit 380 and the forced-air-cooling duct 505 in that order. As described above, at least a portion of the media substrate 390 is exposed through the opening 382 of the media duct unit 380. This allows heat generated in the media substrate 390 to be cooled as the air AR2 passes through the media duct unit 380. The sub-media substrate 400 is disposed on the negative side in the Z-axis direction of the media substrate 390. Since the sub-media board 400 is a board on which lightweight data is written, the amount of heat generated is relatively small, and therefore forced cooling of the sub-media board 400 may be omitted.

[0017] The forced-air-cooling duct 505 has a forced-air-cooling duct inlet 541 that opens toward the positive side in the X-axis direction. Air AR3 is drawn into the forced-air-cooling duct inlet 541. This allows the air AR3 to pass through the forced-air-cooling duct 505. Heat generated in the control circuit board 501 (particularly the heat-generating element) is cooled as the air AR3 passes through the forced-air-cooling duct 505. Some of the heat generated in the control circuit board 501 is also cooled by the sensor duct unit 520. The cooling fan 506 is connected to the forced-air-cooling duct 505 via a cooling fan connecting hole 544. This places the cooling fan 506 and the forced-air-cooling duct 505 in communication. Therefore, when the cooling fan 506 is activated, the air AR1 to the air AR3 are forcibly passed through the forced-air-cooling duct 505. The cooling fan 506 has an exhaust duct unit 370 that opens toward the positive side in the X-axis direction. The air AR1 to air AR3 that has passed through the forced air-cooling duct 505 is exhausted to the outside of the imaging device 100 via the exhaust duct unit 370 by the operation of the cooling fan 506.

[0018] <Main unit configuration> FIG. 6 is an exploded perspective view of the main unit of the imaging device. As shown in FIG. 6, the imaging device 100 has a main unit 500. The main unit 500 is composed of a control circuit board 501, a film (flexible member) 503, a heat dissipation gap filler (thermal conductive member) 504, a forced air-cooling duct 505, and a cooling fan 506. These components constituting the main unit 500 are arranged in order from the positive side to the negative side along the normal direction of the control circuit board 501, i.e., the Z-axis direction. Therefore, of these components, the control circuit board 501 is positioned closest to the subject. The forced air-cooling duct 505 is a flat-shaped member arranged opposite the control circuit board 501. The forced air-cooling duct 505 is made of a metal material with relatively high thermal conductivity, such as aluminum, and is thermally connected to a heating element 610 mounted on the control circuit board 501. As described above, the heating element 610 is an element that generates heat when electricity is applied. Heat generated by the heat generating element 610 is exchanged with air AR2 drawn into the forced air cooling duct 505 by the rotation of the cooling fan 506. This allows the heat generating element 610 to be forcibly cooled.

[0019] A heat dissipation gap filler (heat dissipation filler) 504 is disposed between the heat generating element 610 and the forced-air cooling duct 505. The heat dissipation gap filler 504 is a thermally conductive member that transfers heat from the heat generating element 610 to the forced-air cooling duct 505. In this embodiment, the heat dissipation gap filler 504 is provided in contact with a surface 505a of the forced-air cooling duct 505 that faces the control circuit board 501, i.e., the surface 505a facing the positive side in the Z-axis direction. The heat dissipation gap filler 504 is in a paste form and hardens over time after being applied to the surface 505a. The hardened heat dissipation gap filler 504 has extremely strong adhesive strength to the surface 505a, making it difficult to peel off from the surface 505a. The hardened heat dissipation gap filler 504 has a flat shape in the configuration shown in FIG. 6, but is not limited to this. Furthermore, the heat dissipation gap filler 504 is not particularly limited, and for example, a filler containing a ceramic filler having thermal conductivity and a binder made of a silicone-based resin that bonds the fillers together can be used.

[0020] Here, in the imaging device 100, a flexible heat-dissipating sheet may be used instead of the heat-dissipating gap filler 504. Heat-dissipating sheets are typically used sandwiched between components that are subject to heat exchange. However, depending on various conditions, such as the material and thickness of the heat-dissipating sheet, the heat-dissipating sheet may exert a force on each component that may deform the component. In this case, there is a concern that the control circuit board 501 may be deformed, such as bending, due to the force from the heat-dissipating sheet, resulting in defects or breakdowns. In contrast, the heat-dissipating gap filler 504 hardens, which alleviates the above concerns compared to a heat-dissipating sheet. Alternatively, a thermal grease may be used instead of the heat-dissipating gap filler 504. Unlike the heat-dissipating gap filler 504, the thermal grease does not harden and remains liquid. As a result, the heat-dissipating gap filler 504, compared to thermal grease, can prevent, for example, pumping out due to thermal contraction and expansion, and leakage due to vibration.

[0021] <Layout of heating elements (elements) on the control circuit board> FIG. 7 is a plan view of the control circuit board. As shown in FIG. 7, heating elements 601a, 601b, and 601c are mounted as heating elements 610 on a surface 501a of control circuit board 501 facing the negative side in the Z axis direction. Heating elements 601a to 601c are arranged at intervals from one another along the X axis direction. Heating elements 601a to 601c are, for example, CPUs. Note that the shapes and sizes of heating elements 601a to 601c are not limited to those shown in FIG. 7. Furthermore, although the number of heating elements constituting heating element 610 is three in the configuration shown in FIG. 7, this is not limited thereto and may be, for example, one, two, four, or more. Conductive members 620a, 620b, and 620c are mounted on surface 501a of control circuit board 501. Conductive members 620a to 620c are arranged at intervals from one another, but their locations are not particularly limited. Conductive members 620a to 620c each protrude from surface 501a and function as a connection portion electrically connected to forced-air cooling duct 505. The shapes and sizes of conductive members 620a to 620c are not limited to those in the configuration shown in FIG. 7. Furthermore, although the number of conductive members is three in the configuration shown in FIG. 7, this is not limiting and the number may be one, two, four or more, for example.

[0022] <Relationship between heat dissipation gap filler and film> FIG. 8 is a diagram showing the positional relationship of a control circuit board, a film, a heat dissipation gap filler, and a forced-air-cooling duct in an assembled state. As shown in FIG. 8, a film 503 is disposed between a heat generating element 610 of a control circuit board 501 and a heat dissipation gap filler 504. The film 503 is a flexible sheet-like member. The material of the film 503 is not particularly limited and may be, for example, a resin material such as polyester. The thickness of the film 503 is preferably, for example, several μm to several tens of mm. When heat is generated from the heat generating element 610, the heat can be quickly transferred to the forced-air-cooling duct 505 via the film 503 and the heat dissipation gap filler 504 in that order. In this way, the film 503 can ensure sufficient thermal conductivity.

[0023] The film 503 is sandwiched between the heating element 610 and the heat-dissipating gap filler 504. This prevents the heating element 610 and the heat-dissipating gap filler 504 from coming into close contact with each other. This adhesion prevention effect allows the forced-air-cooling duct 505 to be easily separated together with the heat-dissipating gap filler 504 from the control circuit board 501 when the main unit 500 is disassembled, for example, to repair the control circuit board 501 or replace the heating element 610. This eliminates the need to remove the heat-dissipating gap filler 504 from the control circuit board 501, which leaves a portion of the heat-dissipating gap filler 504 remaining on the control circuit board 501. As a result, repair of the control circuit board 501, replacement of the heating element 610, and the like can be easily performed. Since the film 503 is disposed between the heating element 610 and the heat-dissipating gap filler 504 of the control circuit board 501 in the assembled state of the main unit 500, disassembly workability during repairs and the like is improved. When the main unit 500 is disassembled, the film 503 may be in direct contact with the heat-dissipating gap filler 504 or may be peeled off from the heat-dissipating gap filler 504. If the film 503 is in direct contact with the heat-dissipating gap filler 504, the film 503 may be peeled off from the heat-dissipating gap filler 504 and replaced with a new film 503. As described above, the film 503 is preferably flexible and has a thickness within the above-mentioned numerical range. This flexibility, combined with the above-mentioned numerical range, allows the film 503 to easily and sufficiently conform to the heat-generating element 610 and the heat-dissipating gap filler 504, regardless of the number, arrangement position, or surface shape of the heat-generating element 610 and the heat-dissipating gap filler 504.

[0024] <Film positioning> As described above, film 503 is a member that can exhibit an adhesion prevention effect, preventing heat generating element 610 of control circuit board 501 and heat dissipation gap filler 504 from adhering to each other. However, because film 503 is made of a flexible sheet material, it is prone to misalignment, and if such misalignment occurs, there is a risk that the adhesion prevention effect will not be fully exhibited. Therefore, main unit 500 (imaging device 100) is configured to enable positioning of film 503, that is, to prevent misalignment. The configuration and operation of this are described below.

[0025] FIG. 9 is a front view of the film and the forced-air-cooling duct as viewed from the front side of the imaging device. As shown in FIG. 9, the main unit 500 has a positioning device 800 that positions the film 503. The positioning device 800 is configured to position the film 503 at a position that prevents the heat generating element 610 of the control circuit board 501 from coming into close contact with the heat dissipation gap filler 504. Hereinafter, the state in which the film 503 is positioned may be referred to as the "positioned state." In this embodiment, the positioning device 800 has a through-hole (positioning hole) 801 that penetrates the film 503 and a protrusion 802 that protrudes from the forced-air-cooling duct 505 toward the positive side in the Z-axis direction. The protrusion 802 is formed, for example, by a boss (pin) that is screwed or press-fitted into the forced-air-cooling duct 505 and passes through the through-hole 801. Two through-holes 801 and two protrusions 802 are provided. When viewed from the Z-axis direction, the two through holes 801 are arranged on opposite sides of the heating element 610 (see FIGS. 8 and 9). On the other hand, the two protrusions 802 are also arranged on opposite sides of the heating element 610, similar to the through holes 801 (see FIGS. 8 and 9). This allows the two positioning locations for the film 503 to be spaced as far apart as possible. Note that, in positioning, it is preferable to space the two positioning locations as far apart as possible.

[0026] By the positioning means 800 configured as described above, the position of the film 503 in the X-axis direction and the Y-axis direction is restricted, and the film 503 is reliably positioned at a position that prevents close contact between the heating element 610 and the heat-dissipating gap filler 504. This prevents the film 503 from shifting position, and therefore maintains the state in which the film 503 exerts its effect of preventing close contact. As described above, the film 503 is sandwiched between the heating element 610 and the heat-dissipating gap filler 504. This restricts the position of the film 503 in the Z-axis direction. This restriction of the position in the Z-axis direction, combined with the positioning in the X-axis direction and the Y-axis direction by the positioning means 800, more reliably maintains the positioned state of the film 503.

[0027] The protrusion 802 is cylindrical. The through-hole 801 is circular, and its radius is larger than the radius of the protrusion 802 by the clearance C. Therefore, in this embodiment, the cylindrical protrusion 802 and the circular through-hole 801 have a loose fit. This improves the conformability (shape conformability) of the film 503 to the heating element 610 and the heat-dissipating gap filler 504 described above. Note that although the number of through-holes 801 and protrusions 802 formed is two in this embodiment, this is not limiting and any number may be at least two. Furthermore, although the protrusion 802 is provided in the forced-air-cooling duct 505 in this embodiment, this is not limiting and the protrusion 802 may be provided in the control circuit board 501, for example. In addition, in this embodiment, the positioning means 800 is configured to have a through hole 801 and a protrusion 802, but is not limited to this and may be configured, for example, as a part that is provided in a part of the main unit 500 and can be positioned by abutting the edge of the film 503 against it.

[0028] FIG. 10 is a rear view of the control circuit board and film as viewed from the rear side of the imaging device. As shown in FIG. 10, film 503 has recessed portion 820a that avoids interference with conductive member 620a of control circuit board 501 when positioned, recessed portion 820b that avoids interference with conductive member 620b, and recessed portion 820c that avoids interference with conductive member 620c. Recessed portions 820a and 820b are each formed by penetrating film 503, and recessed portion 820c is formed by an edge of film 503 intruding toward the center of film 503. Such recessed portions 820a to 820c expose conductive members 620a to 620c toward forced-air-cooling duct 505. This allows electrical connection between conductive members 620a to 620c and forced-air-cooling duct 505. Conductive members 620a and 620c also function as vent holes through which air can pass, improving heat dissipation. Furthermore, the areas around conductive members 620a and 620c are more easily deformed, improving the ability of film 503 to conform to heating element 610 and heat-dissipating gap filler 504.

[0029] <<Second embodiment>> The second embodiment will be described below with reference to FIGS. 11 and 12. Differences from the previous embodiment will be mainly described, and similar details will not be described. FIG. 11 is a front view of a forced-air-cooling duct of an imaging device incorporating an electronic device according to the second embodiment, as viewed from the front side of the imaging device. FIG. 12 is a diagram illustrating the positional relationship of a control circuit board, a film, a heat dissipation gap filler, and a forced-air-cooling duct in an assembled state. As shown in FIG. 11, the forced-air-cooling duct 505 has a convex shape 900 (the area surrounded by a dashed line in FIG. 11) that protrudes toward the negative side in the Z-axis direction. As shown in FIG. 12, the convex shape 900 is formed opposite the heat-generating element 610 via the heat-dissipation gap filler 504 and the film 503. This allows the convex shape 900 to function as a maintaining means for maintaining a constant distance D between the heat-generating element 610 and the forced-air-cooling duct 505 in the Z-axis direction. Maintaining a constant distance D prevents differences in heat transfer performance to the forced-air-cooling duct 505 for each heat-generating element 610.

[0030] <<Third Embodiment>> The third embodiment will be described below with reference to FIGS. 13 and 14. Differences from the previous embodiments will be mainly described, and similar details will not be described. FIG. 13 is a front view of a forced-air-cooling duct of an imaging device incorporating an electronic device according to the third embodiment, as viewed from the front side of the imaging device. The forced-air-cooling duct 505 has a heat-dissipating rib (rib) 1004 protruding from a surface 505a facing the positive side in the Z-axis direction. The heat-dissipating rib 1004 is integrally formed with the forced-air-cooling duct 505 and has a shape that surrounds the heat-dissipating gap filler 504 when viewed from the Z-axis direction. FIG. 14 is a cross-sectional view taken along line BB in FIG. 13. As shown in FIG. 14, the heat-dissipating rib 1004 surrounds the heat-dissipating gap filler 504 and the heat-generating element 610. This allows the film 503 to be disposed between the heat-dissipating gap filler 504 and the heat-generating element 610, and to be in contact with the side of the heat-generating element 610. The contact area of ​​film 503 with heating element 610 increases by the amount that film 503 comes into contact with the side surface of heating element 610. This allows heat from heating element 610 to be rapidly transferred to forced air cooling duct 505 via film 503. The distance between the side surface of heating element 610 and heat dissipation rib 1004 is preferably equal to or less than half the thickness of film 503. This allows film 503 to be compressed by heat dissipation rib 1004 and to be in reliable contact with the side surface of heating element 610.

[0031] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist thereof. Note that, although the imaging device 100 is cited as an example of a device to which the electronic device of the present invention can be applied in the above-described embodiments, the present invention is not limited to this, and may also be applied to information processing devices such as desktop or notebook personal computers, tablet terminals, smartphones, etc.

[0032] The disclosure of each embodiment includes the following configuration. (Configuration 1) A circuit board having at least one heating element that generates heat when energized; a cooling duct disposed opposite the circuit board and through which air for cooling the heat generating element passes; a heat dissipation filler provided in contact with a surface of the cooling duct facing the circuit board and having thermal conductivity for transferring heat from the heat generating element to the cooling duct; a flexible member provided between the circuit board and the heat dissipation filler and having flexibility; and a positioning means for positioning the flexible member at a position where contact between the circuit board and the heat dissipation filler can be prevented. (Configuration 2) The electronic device described in Configuration 1, characterized in that the positioning means has a through hole formed through the flexible member, and a protrusion formed on the cooling duct or the circuit board and inserted into the through hole. (Configuration 3) The electronic device according to configuration 2, wherein at least two of the through holes and at least two of the protrusions are provided. (Configuration 4) An electronic device described in configuration 3, characterized in that when viewed from the normal direction of the circuit board, the two through holes are arranged on opposite sides of the heating element, and the two protrusions are also arranged on opposite sides of the heating element. (Configuration 5) The through hole is circular, 5. The electronic device according to any one of configurations 2 to 4, wherein the protrusion is cylindrical and has a loose fit with the through hole. (Configuration 6) The circuit board has a plurality of the heating elements, 6. The electronic device according to any one of configurations 1 to 5, wherein the positioning means positions the flexible member so as to prevent contact between the heat generating elements and the heat dissipating filler. (Configuration 7) The heat generating element is provided on a surface of the circuit board facing the cooling duct, 7. The electronic device according to any one of configurations 1 to 6, wherein the flexible member is sandwiched between the heat generating element and the heat dissipating filler. (Configuration 8) The circuit board has a connecting portion that protrudes from a surface facing the cooling duct and is electrically connected to the cooling duct, 8. The electronic device according to any one of configurations 1 to 7, wherein the flexible member has a recess for avoiding interference with the connecting portion. (Configuration 9) The electronic device according to any one of configurations 1 to 8, wherein the flexible member is sheet-shaped. (Configuration 10) The electronic device according to any one of configurations 1 to 9, further comprising a fan that forcibly passes the air through the cooling duct. (Configuration 11) The electronic device described in Configuration 10, characterized in that when viewed from the normal direction of the circuit board, the circuit board, the flexible member, the heat dissipation filler, the cooling duct, and the fan are arranged in this order along the normal line. (Configuration 12) The electronic device is an imaging device having an imaging function, 12. The electronic device according to configuration 11, wherein the circuit board is located closest to the subject among the circuit board, the flexible member, the heat dissipation filler, the cooling duct, and the fan. (Configuration 13) The circuit board has a plurality of the heat generating elements provided on a surface facing the cooling duct, 13. The electronic device according to any one of configurations 1 to 12, further comprising a maintaining means for maintaining a constant distance between the plurality of heat generating elements and the cooling duct in the normal direction of the circuit board. (Configuration 14) An electronic device described in any one of configurations 1 to 13, characterized in that the cooling duct has a rib that protrudes from the surface facing the circuit board and has a shape that surrounds the heat generating element when viewed from the normal direction of the circuit board. (Configuration 15) The electronic device according to any one of configurations 1 to 14, which is an imaging device having an imaging function. [Explanation of symbols]

[0033] 100 Imaging device 501 Control circuit board 503 Film 504 Heat dissipation gap filler 505 Forced air cooling duct 506 Cooling Fan 610 Heating element 800 Positioning means 801 Through hole 802 Protrusion

Claims

1. a circuit board having at least one heating element that generates heat when energized; a cooling duct disposed opposite the circuit board and through which air for cooling the heat generating element passes; a heat dissipation filler provided in contact with a surface of the cooling duct facing the circuit board and having thermal conductivity for transferring heat from the heat generating element to the cooling duct; a flexible member provided between the circuit board and the heat dissipation filler and having flexibility; and a positioning means for positioning the flexible member at a position where contact between the circuit board and the heat dissipation filler can be prevented.

2. 2. The electronic device according to claim 1, wherein the positioning means comprises a through hole formed through the flexible member, and a protrusion formed on the cooling duct or the circuit board and inserted through the through hole.

3. 3. The electronic device according to claim 2, wherein at least two of the through holes and at least two of the protrusions are provided.

4. The electronic device described in claim 3, characterized in that when viewed from the normal direction of the circuit board, the two through holes are arranged on opposite sides of the heating element, and the two protrusions are also arranged on opposite sides of the heating element.

5. The through hole is circular, 3. The electronic device according to claim 2, wherein the protrusion is cylindrical and has a clearance fit with the through hole.

6. the circuit board has a plurality of the heating elements; 2. The electronic device according to claim 1, wherein the positioning means positions the flexible member so as to prevent contact between the heat generating elements and the heat dissipating filler.

7. the heat generating element is provided on a surface of the circuit board facing the cooling duct, 2. The electronic device according to claim 1, wherein the flexible member is sandwiched between the heat generating element and the heat dissipating filler.

8. the circuit board has a connection portion that protrudes from a surface facing the cooling duct and is electrically connected to the cooling duct, 2. The electronic device according to claim 1, wherein the flexible member has a recess for avoiding interference with the connecting portion.

9. 2. The electronic device according to claim 1, wherein the flexible member is sheet-shaped.

10. 2. The electronic device according to claim 1, further comprising a fan for forcibly passing the air through the cooling duct.

11. 11. The electronic device according to claim 10, wherein, when viewed from a normal direction of the circuit board, the circuit board, the flexible member, the heat dissipation filler, the cooling duct, and the fan are arranged in this order along the normal line.

12. the electronic device is an imaging device having an imaging function, 12. The electronic device according to claim 11, wherein the circuit board is located closest to the subject among the circuit board, the flexible member, the heat dissipation filler, the cooling duct, and the fan.

13. the circuit board has a plurality of the heat generating elements provided on a surface facing the cooling duct, 2. The electronic device according to claim 1, further comprising a maintaining means for maintaining a constant distance between the plurality of heat generating elements and the cooling duct in the normal direction of the circuit board.

14. 2. The electronic device according to claim 1, wherein the cooling duct has a rib that protrudes from a surface facing the circuit board and has a shape that surrounds the heat generating element when viewed from a normal direction of the circuit board.

15. 2. The electronic device according to claim 1, wherein the electronic device is an imaging device having an imaging function.

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