electronic machinery

Abstract

For electronic devices, efficient heat dissipation is achieved by using a simple duct and heat sink heat dissipation structure to address multiple heat sources. [Solution] The electronic device includes a duct composed of a duct cover on which a first heat source is mounted and a duct base on which a second heat source is mounted. A heat dissipation section is provided on the duct base and extends in the direction of the duct cover. A gap is provided between the duct cover and the tip of the heat dissipation section, and at least a portion of the tip of the heat dissipation section and the duct cover are thermally connected by a heat conductive member placed in the gap. There are multiple heat conductive members, each spaced apart at the tip of the heat dissipation section. Furthermore, when viewed from the direction in which the heat dissipation section extends, a portion of the heat conductive members projectively overlaps with the second heat source.

Description

Technical Field

[0001] The present invention relates to an electronic device, and particularly to an electronic device that efficiently dissipates heat from an electronic device having a heat dissipation structure using a plurality of heat sources and ducts.

Background Art

[0002] Heat dissipation in an electronic device is directly related to the performance, reliability, and lifespan of the device, and is an extremely important factor. In particular, in recent years, electronic devices have a very high processing capacity with the high functionality and miniaturization of semiconductor devices, and as a result, the power consumption tends to increase, and efficient heat dissipation has become an important issue. When an electronic device is used in a high-temperature environment exceeding its operating temperature, there is a concern about the occurrence of malfunction of the device and the cause of failure.

[0003] On the other hand, in portable devices and the like, miniaturization of the device is required. However, in general, the heat dissipation performance deteriorates when the device is miniaturized, and thus an electronic device is required to have a heat dissipation structure with high heat dissipation efficiency. As an example of an electronic device having such a heat dissipation structure, there is one that includes a duct (ventilation path for heat dissipation) inside the device. In such an electronic device, by providing a forced air cooling structure in which outside air is taken into the duct and ventilated to the heat sink inside the duct, high heat dissipation performance is realized with a simple structure.

[0004] Regarding a structure in which a duct is provided in an imaging device to cool a substrate, for example, it is disclosed in Patent Document 1. In the heat dissipation structure of Patent Document 1, main substrates 302, 303, 304 serving as heat sources are arranged between duct covers 404, 406 of a duct provided inside the imaging device. Then, heat sink / ducts 402, 403 are thermally connected and arranged so as to be sandwiched therebetween (FIGS. 8, 9, paragraphs [004I] to

[0047] ). With such a heat sink / duct structure, heat dissipation of the main substrates serving as front and rear heat sources can be performed.

[0005] Furthermore, another cooling structure for the imaging device is disclosed, for example, in Patent Document 2. The fan duct unit 301 of the heat dissipation structure described in Patent Document 2 is configured with a right duct 302 and a left duct 303 surrounding a single duct (Figure 25, paragraph

[0080] ). In this case, the right duct 302 is provided with a right duct fin 331, and the left duct 303 is provided with a left duct fin 341 (Figure 21, paragraphs

[0070] ,

[0071] , Figure 22, paragraphs

[0075] ,

[0076] ). Heat dissipation rubber is attached to the opposing surface of the right duct 302 to dissipate heat generated by heat sources such as the front-end IC 600, image processing IC 602, and memory 603 to the duct side. Similarly, the left duct 303 also dissipates heat generated by heat sources such as the back-end IC 611 and format conversion IC 612 to the duct side via heat dissipation rubber. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-98245 [Patent Document 2] Japanese Patent Publication No. 2017-116817 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In the above-mentioned Patent Document 1, the structure was such that a heat sink and duct were arranged so as to sandwich multiple main circuit boards that served as heat sources.

[0008] Furthermore, in the aforementioned Patent Document 2, the structure involved providing fins around a single duct to dissipate heat from ICs that serve as heat sources and are installed on multiple substrates.

[0009] However, the heat dissipation structures described in Patent Documents 1 and 2 above have the problem that the duct structure becomes complicated because it is necessary to arrange separate heat sinks containing multiple fins for multiple heat sources (substrates).

[0010] The object of the present invention is to provide an electronic device that can efficiently dissipate heat from multiple heat sources using a simple heat dissipation structure consisting of a duct and a heat sink. [Means for solving the problem]

[0011] The electronic device of the present invention preferably comprises a duct composed of a duct cover and a duct base, a heat dissipation section provided on the duct base and extending in the direction of the duct cover, and a gap provided between the duct cover and the tip of the heat dissipation section, such that the tip of the heat dissipation section and at least a part of the duct cover are thermally connected by a heat conductive member placed in the gap. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an electronic device that can efficiently dissipate heat from multiple heat sources using a simple heat dissipation structure consisting of a duct and a heat sink. [Brief explanation of the drawing]

[0013] [Figure 1A] This is a perspective view of the imaging device from the front. [Figure 1B] This is a perspective view of the imaging device from the rear. [Figure 2] This is a side view showing the inside of the imaging device with the top cover, intake duct cover, and exhaust duct cover removed. [Figure 3A] This is a perspective view of the heat dissipation unit in Embodiment 1, as seen from the front of the imaging device. [Figure 3B] This is a perspective view of the heat dissipation unit in Embodiment 1, as seen from the rear of the imaging device. [Figure 4A] Figure 3A is an exploded perspective view of the heat dissipation unit of the imaging device, as seen from the front. [Figure 4B] Figure 3B is an exploded perspective view of the heat dissipation unit of the imaging device, seen from the rear. [Figure 5] Figure 3A is a cross-sectional view of the heat dissipation unit shown in Figure 3A. [Figure 6] It is a partial enlarged view of part B in FIG. 5. [Figure 7] It is an exploded perspective view of the heat dissipation unit in Embodiment 2 as seen from the rear of the imaging device. [Figure 8] It is an exploded perspective view of the heat dissipation unit in Embodiment 3 as seen from the front of the imaging device. [Figure 9A] It is a perspective view of the heat dissipation unit in Embodiment 4 as seen from the front of the imaging device. [Figure 9B] It is a perspective view of the heat dissipation unit in Embodiment 4 as seen from the rear of the imaging device. [Figure 10] It is a cross-sectional view of the main part of the heat dissipation unit in Embodiment 4.

Modes for Carrying Out the Invention

[0014] Hereinafter, each embodiment according to the present invention will be described with reference to FIGS. 1A to 10.

[0015] 〔Embodiment 1〕 Hereinafter, Embodiment 1 according to the present invention will be described with reference to FIGS. 1A to In Embodiment 1, as an electronic device having a heat dissipation structure, an imaging device (camera) will be taken as an example for explanation.

[0016] First, the overall appearance of the imaging device according to one embodiment will be described with reference to FIGS. 1A and 1B. FIG. 1A is a perspective view of the imaging device as seen from the front. FIG. 1B is a perspective view of the imaging device as seen from the rear.

[0017] In the following description, the lens side is the front (front side), the opposite surface is the rear (rear side), the vertically upper side of the imaging device is the top (top side), and the vertically lower side is the bottom (bottom side). Also, hereinafter, as shown in FIGS. 1A and 1B, a three-dimensional coordinate system will be set. Here, the X, Y, and Z-axis directions of the three-dimensional coordinate system respectively correspond to the front-rear, left-right, and up-down directions.

[0018] ​The imaging device 1 is equipped with an interchangeable lens 2. The interchangeable lens 2 is mounted on the front of the imaging device 1 and attached to a lens mount 3 provided on the imaging device 1. As shown in Figure 1A, the exterior of the imaging device 1 mainly consists of a front cover 13, a rear cover 11, a bottom cover 12, and a top cover 4. Furthermore, the top cover 4 is fitted with an exhaust-side duct cover 6 and an intake-side duct cover 5, as shown in Figures 1A and 1B, respectively. Heat generated by the circuit board and other components inside the imaging device 1 is dissipated to the outside of the imaging device 1 by a forced air cooling structure using a fan provided inside the imaging device 1. Therefore, the intake-side duct cover 5 is provided with an external intake port 51 for drawing in outside air, and the exhaust-side duct cover 6 is provided with an external exhaust port 61 for exhausting the drawn-in outside air to the outside of the imaging device 1.

[0019] Next, we will explain the internal structure of the imaging device using Figure 2. Figure 2 is a side view showing the inside of the imaging device with the top cover 4, intake duct cover 5, and exhaust duct cover 6 removed.

[0020] Figure 2 shows the side view of the imaging device 1 with the top cover 4, intake duct cover 5, and exhaust duct cover 6 removed. The front base 14 is fixed to the front cover 13 by screws (not shown). An optical unit 15 is positioned between the lens mount 3 and the image sensor 16. The optical unit 15 incorporates a neutral density filter and the like. Light that has passed through the interchangeable lens 2 passes through the optical unit 15 and then forms an image on the imaging surface of the image sensor 16 on the sensor substrate 17. The image sensor 16 is mounted on the sensor substrate 17 and is UV bonded (bonded with ultraviolet curing resin) to the sensor plate 18. A substrate holder 200 is fixed to the rear cover 11. The main substrate 300 and a duct base 100 having multiple fins 110 are fixed to the substrate holder 200. The duct base 100 and the main substrate 300 are thermally connected (details will be described later). Furthermore, the duct cover 140 is attached to the duct base 100 so as to cover multiple fins 110, thereby forming a duct opening H1 between them (hatched area in Figure 2). The duct opening H1 is positioned to correspond to the external intake port 51 of the intake-side duct cover 5 shown in Figure 1B. This allows the fan 130 attached to the duct base 100 to be driven, enabling air from outside the imaging device 1 to be drawn into the imaging device 1 through the external intake port 51. On the exhaust side, the fan exhaust port 132 (described later in Figure 4A) is positioned to correspond to the external exhaust port 61 provided on the exhaust-side duct cover 6 shown in Figure 1A. That is, the outside air drawn into the imaging device 1 from the external intake port 51 is used to cool the heat source of the main circuit board 300 inside the imaging device, and then exhausted to the outside of the imaging device 1 through the fan exhaust port 132 and the external exhaust port 61. Furthermore, the mounting surface of the main board 300, the connection surface of the duct base 100 to the main board 300, and the intake surface of the fan 130 are all arranged parallel to the YZ plane. In addition, the fan 130 is positioned so that its intake surface projectively overlaps with the mounting surface of the main board 300. This configuration makes it possible to prevent the imaging device 1 from becoming larger in the YZ plane.

[0021] In this embodiment, the multiple fins 110 are shown to be integrally formed on the duct base 100, but a heat sink may be attached to the duct base 100. Also, in Embodiment 1, the shape of the fins 110 is a rib shape with a longitudinal direction in the Y-axis direction, but other shapes such as a pin shape may also be used.

[0022] On the other hand, the sensor board 17 is a circuit board for converting light received by the image sensor 16 mounted on it into electrical signals. The main board 300 is electrically connected to the sensor board 17 and is a circuit board for image processing and video output. Both boards are mounted with electronic components such as ICs that act as heat sources. The heat generated on the sensor board 17 is naturally dissipated by thermal conduction, passing through the sensor plate 18 and front base 14, and finally to the front cover 13, which is an exterior component of the imaging device 1. The sensor plate 18 is made of a material with high thermal conductivity, such as an aluminum alloy, which effectively diffuses and dissipates the heat generated on the sensor board 17. On the other hand, the heat generated on the main board 300 is dissipated by the heat dissipation unit 1000, which consists of the duct base 100, duct cover 140, fan 130, etc.

[0023] Next, the structure of the heat dissipation unit will be explained using Figures 3A to 4B. Figure 3A is a perspective view of the heat dissipation unit in Embodiment 1, as seen from the front of the imaging device. Figure 3B is a perspective view of the heat dissipation unit in Embodiment 1, seen from the rear of the imaging device. Figure 4A is an exploded perspective view of the heat dissipation unit of the imaging device shown in Figure 3A, viewed from the front. Figure 4B is an exploded perspective view of the heat dissipation unit of the imaging device shown in Figure 3B, viewed from the rear.

[0024] The main circuit board 300, which forms part of the heat dissipation unit 1000, is fixed to the circuit board holder 200, as shown in Figures 3A and 3B. The duct base 100 is fixed to the circuit board holder 200 and is thermally connected to the main circuit board 300. The duct cover 140 is fixed to the duct base 100, and the sub-circuit board 400 is further fixed to the duct cover 140. A flow path leading to the fan exhaust port 132 is formed between the duct base 100 and the duct cover 140. As mentioned earlier, outside air is taken in through the duct opening H1 (airflow w1) by the drive of the fan 130 attached to the duct base 100, and passes through the flow path surrounded by the duct cover 140, the duct base 100 and the multiple fins 110 provided thereon. In this configuration, the fins 110 act as heat dissipation units, and the heat transferred from the main board 300 to each fin 110 is transferred to the airflow w1, which is then exhausted from the fan exhaust port 132 (airflow w2). With this configuration of the heat dissipation unit 1000, the heat from the main board 300 is dissipated to the outside of the imaging device 1.

[0025] As shown in the exploded perspective views of Figures 4A and 4B, the heat dissipation unit 1000 mainly consists of a substrate holder 200, a main substrate 300, a duct base 100, a duct cover 140, a fan 130, and a sub-sub-substrate 400. The main substrate 300 is fixed to the substrate holder 200 by screws. The main substrate 300 also has a heat source P1 (first heat source), which is the main heat source of the imaging device 1, mounted on it. The duct base 100 is fixed to the substrate holder 200 by fixing screws 116 with a heat conductive member 301 sandwiched between it and the heat source P1. Thus, the heat source P1 and the duct base 100 are thermally connected via the heat conductive member 301. Multiple fins 110 are integrally formed on the duct base 100, extending toward the duct cover 140. These multiple fins 110 are arranged in parallel to form a main stream in the Y-axis direction. The duct cover 140 is attached to the mounting portion 112 of the duct base 100 by fixing screws 144, so as to cover the fins 110. As shown in Figure 4B, the duct cover 140 has a plurality of heat conductive members 117a to c arranged parallel to the longitudinal direction of the fins 110 and at positions corresponding to the tips of some of the fins (described later with reference to Figure 6). With this configuration, as shown in Figures 3A and 3B, when the heat dissipation unit 1000 is integrated, the duct cover 140 and the tips of some of the fins 110 are thermally connected via the heat conductive members 117a to c. The heat conductive members 117a to c are made of a material that is flexible and has thermal conductivity. For example, this could be a heat conductive sheet or a heat conductive grease, but more preferably it is made of a heat conductive gap filler that can be applied to any shape using a syringe (injection device). Furthermore, it is preferable that the material has relatively high flexibility immediately after application and hardens or semi-hardens after a certain period of time (specifically, after the heat dissipation unit 1000 is assembled and integrated). Since the heat conductive members 117a to c have flexibility at least when assembling the duct cover 140 to the duct base 100, it is possible to prevent excessive load from being placed on the duct cover 140 at the locations where the heat conductive members 117a to c are placed.In other words, it is possible to thermally connect the duct cover 140 and the tip of the fin 110 of the duct base 100 without causing deformation of the duct cover 140 due to overload. After the duct cover 140 is attached to the duct base 100, the fan 130 is fixed to the duct base 100 with fixing screws 142. The duct cover 140 is provided with a cover opening H0 having a diameter equal to or greater than the diameter of the fan's intake port, which allows the air inside the duct consisting of the duct base 100 and the duct cover 140 to be smoothly guided to the fan intake port 131 shown in Figure 4B. Furthermore, as shown in Figure 4B, a cushioning member 141 is attached to the fan 130 so as to surround the fan intake port 131. When the fan 130 is attached to the duct base 100, the cushioning member 141 is compressed in the X-axis direction between the duct cover 140 and the fan 130. This prevents air leakage between the two components. With this configuration, an airflow path is formed consisting of the duct base 100, the duct cover 140, and the fan 130. As shown in Figure 4A, the sub-board 400 is fixed to the spacer 143, which is attached to the duct cover 140 by crimping or the like, with fixing screws 401. As shown in Figures 4A and 4B, the main board 300 has an electronic component that serves as a heat source P1, and the sub-board 400 has an electronic component that serves as a heat source P2 (second heat source). Here, a heat conductive member 301 is compressed and sandwiched between the main board 300 and the duct base 100 at a position corresponding to the heat source P1, and a heat conductive member 410 is compressed and sandwiched between the sub-board 400 and the duct cover 140 at a position corresponding to the heat source P2. Thus, the heat source P1 is thermally connected to the duct base 100, and the heat source P2 is thermally connected to the duct cover 140. Here, it is preferable that the duct base 100 and the duct cover 140 are made of high thermal conductivity materials such as die-cast aluminum and aluminum alloy, respectively.

[0026] With this configuration of the heat dissipation unit 1000, heat generated by heat source P1 is transferred to the duct base 100 and the multiple fins 110 arranged thereon via the heat conduction member 301. On the other hand, heat generated by heat source P2 is transferred to the duct cover 140 via the heat conduction member 410. In other words, heat sources P1 and P2 are arranged so as to sandwich the duct consisting of the duct base 100 and the duct cover 140, and each heat source is thermally connected to the duct. Here, the heat conduction members 301 and 410 can be made of materials with high thermal conductivity and flexibility, such as the thermal conductive gap filler mentioned above, as well as thermal conductive sheets and thermal conductive grease.

[0027] Next, the thermal connections between each heat source on the heat dissipation unit and the duct will be described in detail using Figures 5 and 6. Figure 5 is a cross-sectional view AA of the heat dissipation unit shown in Figure 3A. Figure 6 is a magnified view of section B in Figure 5.

[0028] As shown in Figure 5, the duct base 100 has multiple fins 110 arranged in parallel parallel to the Y-axis, and the tip of each fin 110 extends toward the duct cover 140. A sub-substrate 400 having a heat source P2 is fixed to a spacer 143 provided on the duct cover 140. Furthermore, a heat conductive member 410 is sandwiched between the heat source P2 and the duct cover 140. On the other hand, a heat conductive member 301 is sandwiched between the heat source P1 mounted on the main substrate 300 and the duct base 100. With this configuration, in the heat dissipation unit 1000, the heat source P2 and the duct cover 140, and the heat source P1 and the duct base 100 are thermally connected.

[0029] Next, the heat dissipation paths of heat sources P1 and P2 will be explained in detail using the partially enlarged view shown in Figure 6. As shown in Figure 6, when the duct cover 140 is attached to the mounting portion 112 of the duct base 100, a gap Δx in the X-axis direction is provided between the surface of the duct cover 140 facing the tip of the fin 110 and the tip of the fin 110. By providing this gap Δx when assembling the duct cover 140 to the duct base 100, deformation of the duct cover 140 due to contact between the tip of the fin 110 and the duct cover 140 is prevented. The heat generated by the heat source P1 shown in Figure 5 is transferred to the duct base 100 via the heat conduction member 301. Subsequently, the heat is diffused to the multiple fins 110 of the duct base 100, as shown by the heat flow Q3 in Figure 6. On the other hand, the heat from the heat source P2 is transferred to the duct cover 140 via the heat conduction member 410 and diffused in the plane direction (YZ plane) of the duct cover 140, as shown by the heat flow Qh. As described above, heat conductive members 117a to c are sandwiched in the gap between the duct cover 140 and the tips of some of the fins 110 (fin tips 111a to c). As a result, some of the heat transferred from the heat source P2 to the duct cover 140 is transferred to the fin tips 111a to c by heat conduction through the heat conductive members 117a to c, as shown in the heat flow Qt. Therefore, compared to the case where the heat conductive members 117a to c are not provided, an additional heat dissipation path for the heat source P2 to the duct is added, making it possible to cool the heat source P2 effectively.

[0030] Generally, when fins are attached to a base, the tip of the fin is at a higher position relative to the base, while the base of the fin is lower than the tip. However, as described above, by newly providing a heat dissipation path between the duct cover 140 and the fin tip using heat conductive members 117a to 117c, heat can be effectively transferred to the fin tip. As a result, the temperature from the base to the tip of the fin can be made uniform, improving the fin efficiency. Consequently, it is possible to improve the heat dissipation efficiency of the heat dissipation unit 1000 compared to the case without the heat conductive members 117. Note that when viewed from the extending direction (X-axis direction) of each fin 110, at least a portion of the heat conductive members 117a to 117c is positioned so as to project onto the heat source P2. By arranging the heat conductive members 117a to 117c in this way, the distance from the heat source P2 to the fin tips 111a to 111c can be shortened, and the thermal resistance between the two can be reduced. Furthermore, as mentioned above, the heat conductive members 117a to c are thermally conductive gap fillers, etc., and are flexible at least when assembling the duct cover 140 to the duct base 100. Therefore, even when they are sandwiched between the duct cover 140 and the fin tips 111a to c as shown in Figure 6, it is possible to reduce the load on the duct cover 140. Moreover, the multiple heat conductive members 117a to c are arranged spaced apart from each other. This ensures that there is space for the heat conductive members 117a to c to escape when they are compressed and deformed when the duct cover 140 is attached to the mounting portion 112. Therefore, it is possible to further reduce the load on the duct cover 140 due to the presence of the heat conductive members 117a to c.

[0031] In the examples shown in Figures 5 and 6, the case where there are three heat conduction members 117 was explained. However, regarding the load reduction effect described above, it is not necessary to have three heat conduction members 117; the same effect can be achieved by arranging at least two or more heat conduction members spaced apart from each other. On the other hand, there is no limit to the number of heat conduction members 117 that can be arranged; it is sufficient for one or more heat conduction members 117 to be placed in the gap Δx. For example, among the multiple fins 110 provided on the duct base 100, the heat conduction members may be provided not only on some of the tips (fin tips 111a to c), but on all of the tips of the fins 110. The appropriate number of heat conduction members 117 depends on the heat generation amount of heat sources P1 and P2, the heat capacity and material of the heat conduction member 410, the heat capacity and material of the heat conduction member 117, the shape and heat capacity of the fins 110, and is determined by thermal simulation or measurement tests using prototypes.

[0032] As described above, in the electronic device of this embodiment, the heat dissipation structure provided by the heat dissipation unit 1000 allows for effective cooling of any heat source connected to either the duct base 100 or the duct cover 140 that constitutes the duct, without complicating the structure of the device.

[0033] [Embodiment 2]

[0034] Hereinafter, Embodiment 2 of the present invention will be described with reference to Figure 7. Figure 7 is an exploded perspective view of the heat dissipation unit in Embodiment 2, viewed from the rear of the imaging device. This embodiment, like Embodiment 1, relates to a heat dissipation structure used in an imaging device, and the same reference numerals as in Embodiment 1 indicate the same components.

[0035] The following mainly describes the differences from Embodiment 1. As shown in Figure 7, the difference between the heat dissipation unit 2000 of this embodiment and the heat dissipation unit 1000 of Embodiment 1 is that the heat conductive members 117a to c are replaced with heat conductive members 600a to c arranged in different directions. The heat conductive members 600a to c are arranged on the duct cover 140 almost perpendicular to the longitudinal direction of the fins 110 and at positions corresponding to some of the fin tips. That is, when the duct cover 140 is assembled to the duct base 100, each heat conductive member 600a to c is arranged so as to span multiple fins 110. Therefore, the heat source P2 is transferred to the duct cover 140 via the heat conductive member 410, and then transferred to the multiple fin tips via each of the heat conductive members 600a to c. According to this embodiment, adjacent fins are thermally connected to each other via each of the heat conductive members 600a to c, so the temperature difference between each fin can be reduced. This improves the heat dissipation efficiency of the heat dissipation unit 2000. In this embodiment, the three heat conductive members 600a to c are sandwiched between the duct cover 140 and the tips of the fins, but the number is not limited to three; one or more are sufficient. Furthermore, in this embodiment, the heat conductive members 600a to c are arranged almost perpendicular to the longitudinal direction of the fins 110 which are arranged in parallel, but there is no restriction on the angle, and it is sufficient for them to be configured to span multiple fins 110. For example, they may be configured at an angle to the longitudinal direction of the fins 110. Alternatively, the heat conductive members 117a to c shown in the first embodiment and the heat conductive members 600a to c of this embodiment may be combined to form a grid-like heat conductive member sandwiched between the duct cover 140 and the tips of the fins.

[0036] [Embodiment 3] Hereinafter, Embodiment 3 of the present invention will be described with reference to Figure 8. Figure 8 is an exploded perspective view of the heat dissipation unit in Embodiment 3, viewed from the front of the imaging device. This embodiment, like Embodiment 1, relates to a heat dissipation structure used in an imaging device, and the same reference numerals as in Embodiment 1 indicate the same components.

[0037] The following mainly describes the differences from Embodiment 1. As shown in Figure 8, the difference between the heat dissipation unit 3000 of this embodiment and the heat dissipation unit 1000 of Embodiment 1 is that the duct cover 140 has been eliminated and replaced with a sub-board 700. Multiple heat sources P3, such as ICs, are mounted on the sub-board 700. The sub-board 700 is fixed to the mounting portion 112 of the duct base 100 by fixing screws 144. Some of the fins of the duct base 100 are provided with heat conductive members 117a to 117c at their tips. Note that, as in Embodiment 1, the heat conductive members 117 may be configured to be provided on the opposite side of the fin (the sub-board 700 side) (see Figure 6). When the sub-board 700 is fixed to the mounting portion 112, the heat conductive members 117a to 117c are sandwiched between the surface of the sub-board 700 on the negative X-axis side and some of the tips of the fins 110. Therefore, the sub-substrate 700 and some of the tips of the fins 110 are thermally connected via the heat conductive members 117a to c. Thus, the heat generated by the heat source P3 is diffused in the planar direction of the sub-substrate 700 and transferred to some of the tips of the fins 110 via the heat conductive members 117a to c. Therefore, according to the heat dissipation unit 3000 of this embodiment, by eliminating the duct cover 140 shown in embodiments 1 and 2, it is possible to reduce the number of parts while effectively cooling any of the multiple heat sources arranged to sandwich the duct, similar to both embodiments.

[0038] [Embodiment 4] Hereinafter, Embodiment 4 of the present invention will be described with reference to Figures 9A to 10. Figure 9A is a perspective view of the heat dissipation unit in Embodiment 4, as seen from the front of the imaging device. Figure 9B is a perspective view of the heat dissipation unit in Embodiment 4, seen from the rear of the imaging device. Figure 10 is a cross-sectional view of the main part of the heat dissipation unit in Embodiment 4.

[0039] This embodiment, like Embodiment 1, relates to a heat dissipation structure used in an imaging device, and the same reference numerals as in Embodiment 1 indicate the same components.

[0040] The difference between the heat dissipation unit 4000 of this embodiment and the heat dissipation unit 1000 of Embodiment 1 is that the heat source P2 of the sub-substrate 400, which is connected to the duct cover 140 and connected to the fin tip via the heat conductive member 117, has been replaced with the image sensor 16. As shown in Figures 9A and 9B, the image sensor 16 is mounted on the sensor substrate 17 and fixed to a sensor plate 18 made of sheet metal or the like. As shown in Figure 9B, an aperture-shaped portion 19 is provided in the center of the rear surface of the sensor plate 18, and the rear surface of the image sensor 16 is bonded to the aperture-shaped portion 19, thereby thermally connecting the two. Therefore, the heat generated by the image sensor 16 is diffused in the planar direction of the sensor plate 18, starting from the aperture-shaped portion 19 of the sensor plate 18. A graphite sheet 800 is placed between the sensor plate 18 and the duct cover 140. The graphite sheet 800 is provided with a heat transfer section (first heat transfer section) 801 at one end and a heat transfer section (second heat transfer section) 802 at the other end. The heat transfer section 801 is attached to the rear surface of the constricted shape 19 of the sensor plate 18, and the heat transfer section 802 is attached to the front surface of the duct cover 140, using double-sided tape or the like.

[0041] Next, Figure 10 will be used to explain the heat dissipation path of the image sensor to the duct in the heat dissipation unit of Embodiment 4.

[0042] To facilitate the explanation of the structure, the fan 130 and cushion member 141 are not shown in Figure 10. As described above, the heat transfer portion 801 and heat transfer portion 802 of the graphite sheet 800 are bonded to the rear surface of the aperture-shaped portion 19 of the sensor plate 18 and the front surface of the duct cover 140, respectively. Therefore, the heat generated by the image sensor 16 is transferred to the duct cover 140 by heat conduction via the sensor plate 18 and the graphite sheet 800. Subsequently, the heat is transferred from the duct cover 140 to the corresponding fin tip via the heat conduction members 117a to c, similar to Embodiment 1. Also, similar to Embodiment 1, the heat from the heat source P1 of the main substrate 300 is transferred to the duct base 100 and fin 110 via the heat conduction member 301. In other words, the heat dissipation unit of this embodiment makes it possible to effectively cool both the image sensor 16 and the heat source P1, which are arranged to sandwich the duct consisting of the duct base 100 and the duct cover 140. Furthermore, by using a flexible graphite sheet 800 for thermal connection between the image sensor 16 and the duct cover 140, it is possible to thermally connect the two without placing a load on the image sensor 16. Alternatively, other materials with flexibility and thermal conductivity, such as a copper sheet, may be used instead of the graphite sheet 800.

[0043] As described above, according to the heat dissipation structure of this embodiment, by using the graphite sheet 800, the heat generated in the image sensor 16 can be effectively cooled by transferring the heat to the fins 110 on the duct side.

[0044] (Composition 1) The duct consists of a duct cover and a duct base. The duct base is provided and has a heat dissipation section that extends in the direction of the duct cover, A gap is provided between the duct cover and the tip of the heat dissipation section. An electronic device characterized in that at least a portion of the duct cover and the tip of the heat dissipation section are thermally connected by a heat conductive member placed in the gap.

[0045] (Configuration 2) The electronic device according to configuration 1, characterized in that a first heat source and a second heat source are thermally connected to the duct base and the duct cover, respectively.

[0046] (Composition 3) The electronic device according to configuration 2, characterized in that, when viewed from the extending direction of the heat dissipation portion, at least a portion of the heat conductive member projectively overlaps with the second heat source.

[0047] (Composition 4) The electronic device according to any one of configurations 1 to 3, characterized in that the heat conductive members are at least two in number and are spaced apart at the tip of the heat dissipation section.

[0048] (Composition 5) The electronic device according to any one of configurations 1 to 4, characterized in that a plurality of heat dissipation sections are provided, and the heat conductive member is arranged to span across the tips of the plurality of heat dissipation sections.

[0049] (Composition 6) The electronic device according to any one of configurations 1 to 5, characterized in that the heat conductive member is one of a heat conductive sheet, a heat conductive grease, or a heat conductive gap filler.

[0050] (Composition 7) The electronic device according to any one of configurations 1 to 6, characterized in that a part of the duct cover is composed of a circuit board.

[0051] (Composition 8) The duct cover and the second heat source are spaced apart. A heat-conducting sheet is provided, having a first heat transfer section at one end and a second heat transfer section at the other end. The electronic device according to configuration 2, characterized in that the first heat transfer unit is thermally connected to the second heat source, and the second heat transfer unit is thermally connected to the duct cover. [Explanation of symbols]

[0052] 1...Imaging device, 2...Interchangeable lens, lens mount, 3, 4...Top cover, 5...Intake duct cover, 6...Exhaust duct cover, 11...Rear cover, 12...Bottom cover, 13...Front cover, 51...External intake port, 61...External exhaust port, 16...Image sensor, 17...Sensor substrate, 18...Sensor plate, 19...Aperture shape section, 100...Duct base, 110...Fin, 111...Fin tip, 112...Mounting part 116, 142, 144, 401... Fixing screws, 117,301,410,600... Heat conductive material, 130...fan, 131...fan intake, 132...fan exhaust, 140...duct cover, 141...cushioning material, 143...spacer 200... PCB holder, 300... Main board, 400, 700... Sub-board, 800... Graphite sheet 801, 802... Heat transfer section, 1000, 2000, 3000, 4000... Heat dissipation units H0...Cover opening, H1...Duct opening, P1, P2, P3…Heat sources, Qh, Qt, Q3…Heat flow, w1, w2…Airflow, Δx…Gap

Claims

1. The duct consists of a duct cover and a duct base. The duct base is provided and has a heat dissipation section that extends in the direction of the duct cover, A gap is provided between the duct cover and the tip of the heat dissipation section. An electronic device characterized in that at least a portion of the duct cover and the tip of the heat dissipation section are thermally connected by a heat conductive member placed in the gap.

2. The electronic device according to claim 1, characterized in that a first heat source and a second heat source are thermally connected to the duct base and the duct cover, respectively.

3. The electronic device according to claim 2, characterized in that, when viewed from the extending direction of the heat dissipation portion, at least a portion of the heat conducting member projectively overlaps with the second heat source.

4. The electronic device according to claim 1, characterized in that the heat conductive members are at least two in number and are arranged spaced apart at the tip of the heat dissipation section.

5. The electronic device according to claim 1, characterized in that a plurality of heat dissipation sections are provided, and the heat conductive member is arranged to span across the tips of the plurality of heat dissipation sections.

6. The electronic device according to claim 1, characterized in that the heat conductive member is one of a heat conductive sheet, a heat conductive grease, or a heat conductive gap filler.

7. The electronic device according to claim 1, characterized in that a part of the duct cover is composed of a circuit board.

8. The duct cover and the second heat source are spaced apart. A heat-conducting sheet is provided, having a first heat transfer section at one end and a second heat transfer section at the other end. The electronic device according to claim 2, characterized in that the first heat transfer unit is thermally connected to the second heat source, and the second heat transfer unit is thermally connected to the duct cover.

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