Endothermic structure

Abstract

To provide a heat absorption structure capable of reducing a size while securing an electric insulation property between an electronic device and an endotherm member.SOLUTION: A heat absorption structure 1 comprises: a first insulation member 5; and a projected endotherm member 3 that performs endotherm of heat generated by an electron device 11 provided onto the first insulation member 5 via the first insulation member 5. The endotherm member 3 includes a mounting surface 3a where the first insulation member 5 and the electron device 11 are arranged. The first insulation member 5 is formed by being coated between the mounting surface 3a and the electron device 11, and comprises: a second insulation member 9 that is provided between a part of an outer edge side from the first insulation member 5 in the mounting surface 3a and the electron device 11, and is provided to a part of which a creepage distance L of the electron device 11 and the endotherm member 3 regulated by at least the electron device 11, the first insulation member 5, and the endotherm member 3 is shortest, and includes an electric insulation property. The second insulation member 9 is a solid body when the same is provided to the mounting surface 3a.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a heat sink structure. [Background technology]

[0002] A known conventional heat absorbing structure is described in, for example, Patent Document 1. The heat absorbing structure described in Patent Document 1 includes a heat absorbing member (projection) provided on a heat sink for heat dissipation, and a heat dissipation sheet disposed on the heat absorbing member. In the heat absorbing structure, an electronic device is disposed on the heat dissipation sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-79268 A Summary of the Invention [Problem to be solved by the invention]

[0004] The heat dissipation sheet is formed into a predetermined shape and dimensions. Therefore, the production of the heat dissipation sheet is costly. Therefore, in order to reduce costs, a gap filler can be used instead of the heat dissipation sheet. Since the gap filler is in a paste form when applied, it is difficult to control the shape. Therefore, it is difficult to ensure a creepage distance for ensuring electrical insulation between the electronic device and the heat absorbing member. In order to ensure the creepage distance, it is possible to increase the mounting surface of the heat absorbing member on which the gap filler is placed and to increase the area to which the gap filler is applied. However, if the mounting surface of the heat absorbing member is increased, the projected area increases, and the heat absorbing structure becomes larger. Since electronic devices in which the heat absorbing structure is provided tend to be smaller, it is not preferable to increase the size of the heat absorbing structure.

[0005] An object of one aspect of the present invention is to provide a heat absorption structure that can avoid an increase in size while ensuring electrical insulation between an electronic device and a heat absorption member. [Means for solving the problem]

[0006] A heat absorption structure according to one aspect of the present invention is a heat absorption structure comprising a first insulating member having electrical insulation and heat conductivity, and a protruding heat absorption member that absorbs heat generated by an electronic device mounted on the first insulating member via the first insulating member, wherein the heat absorption member has a mounting surface on which the first insulating member and the electronic device are mounted, the first insulating member is formed by being applied between the mounting surface and the electronic device, and a second insulating member having electrical insulation properties is provided between the electronic device and a portion of the mounting surface that is outer than the first insulating member, at least in a portion where the creepage distance between the electronic device and the heat absorption member, which is defined by the electronic device, the first insulating member, and the heat absorption member, is shortest, and the second insulating member is solid when provided on the mounting surface.

[0007] The heat sink structure according to one aspect of the present invention includes a second insulating member. The second insulating member is provided between the electronic device and a portion of the mounting surface that is closer to the outer edge than the first insulating member, at least in a portion where the creepage distance between the electronic device and the heat sink defined by the electronic device, the first insulating member, and the heat sink is the shortest. As a result, even if the first insulating member (e.g., a gap filler) formed by application is used in the heat sink structure, the second insulating member can ensure electrical insulation between the electronic device and the heat sink. In addition, since the second insulating member can ensure electrical insulation between the electronic device and the heat sink in the heat sink structure, there is no need to enlarge the mounting surface of the heat sink. Therefore, it is possible to avoid an increase in size of the heat sink structure.

[0008] In one embodiment, the second insulating member may be disposed so as to surround the first insulating member. In this configuration, the first insulating member is surrounded by the second insulating member over the entire periphery, so that electrical insulation between the electronic device and the heat absorbing member can be further ensured.

[0009] In one embodiment, the second insulating member may have a bottom portion that is disposed between the mounting surface and the first insulating member and has thermal conductivity. In this configuration, the bottom portions of the first insulating member and the second insulating member are disposed between the electronic device and the heat absorbing member, so that electrical insulation between the electronic device and the heat absorbing member can be further ensured. Effect of the Invention

[0010] According to one aspect of the present invention, it is possible to achieve miniaturization while ensuring electrical insulation between an electronic device and a heat absorbing member. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a heat absorption structure according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of a heat absorption structure according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicated explanations are omitted. In the following description, the first direction D1 and the second direction D2 defined in FIG. 1 are used.

[0013] [First embodiment] 1 is provided in an electronic device (e.g., an inverter, a converter, etc.). The heat absorption structure 1 dissipates heat generated in an electronic component E to a cooling mechanism (not shown). The electronic component E is, for example, a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

[0014] 1 and 2, the heat absorption structure 1 includes a heat absorption member 3, a first insulating member 5, a heat transfer member 7, and a second insulating member 9. The electronic component E and the heat transfer member 7 configure an electronic device 11. In FIG. 1, a circuit board CB (see FIG. 2) is omitted from illustration.

[0015] The heat absorbing member 3 is a member that dissipates heat from the electronic device 11. The heat absorbing member 3 shown in Figs. 1 and 2 is, for example, a part of a heat sink (housing) for heat dissipation. The heat absorbing member 3 is a protrusion that protrudes from one surface of the heat sink. In addition to the heat absorbing member 3, multiple other members are arranged on the heat sink. A cooling mechanism is provided below the heat absorbing member 3 (heat sink). The cooling mechanism is, for example, a water-cooled type. A refrigerant flow path (not shown) for passing a refrigerant is provided below the heat absorbing member 3.

[0016] The heat absorbing member 3 is formed of a material having heat conductivity. The heat absorbing member 3 is formed of, for example, aluminum, copper, stainless steel, etc. The heat absorbing member 3 has a protruding shape. In this embodiment, the heat absorbing member 3 has a quadrangular pyramid shape. The heat absorbing member 3 has a mounting surface 3a and four side surfaces 3b. The mounting surface 3a has a rectangular shape. The mounting surface 3a is a flat surface. Each of the four side surfaces 3b has a trapezoidal shape.

[0017] The first insulating member 5 ensures electrical insulation between the electronic device 11 and the heat absorbing member 3, and also transfers heat from the electronic device 11 to the heat absorbing member 3. The first insulating member 5 is formed of a member having electrical insulation and heat conductivity. The first insulating member 5 is, for example, a heat dissipating gap filler. In this embodiment, the first insulating member 5 is, for example, a cured type heat dissipating silicone gap filler.

[0018] The first insulating member 5 is disposed between the heat absorbing member 3 and the heat transfer member 7 (electronic device 11). The first insulating member 5 is disposed (placed) directly on the mounting surface 3a of the heat absorbing member 3. A part (outer edge portion) of the first insulating member 5 may be disposed on the second insulating member 9. The first insulating member 5 is formed by being applied to the mounting surface 3a of the heat absorbing member 3. Specifically, the first insulating member 5 is formed by applying a grease-like (paste-like) insulating member to the mounting surface 3a and curing it.

[0019] The first insulating member 5 is disposed inside the outer edge of the mounting surface 3a of the heat absorbing member 3. In other words, the mounting surface 3a of the heat absorbing member 3 has a portion where the first insulating member 5 is not disposed.

[0020] 1 and 2, the heat transfer member 7 transfers heat from the electronic component E to the first insulating member 5. The heat transfer member 7 is made of a material having thermal conductivity. The heat transfer member 7 is made of, for example, copper.

[0021] The heat transfer member 7 is disposed between the first insulating member 5 and the electronic component E. In this embodiment, as shown in FIG. 2, the cross section of the heat transfer member 7 has a convex shape. The heat transfer member 7 has a first heat transfer section 7A and a second heat transfer section 7B. The width (length in the left-right direction in FIG. 2) of the first heat transfer section 7A is smaller than the width of the second heat transfer section 7B. In the heat transfer member 7, the second heat transfer section 7B is disposed to face the first insulating member 5. A surface 7Aa of the first heat transfer section 7A constitutes a mounting surface on which the electronic device 11 is placed. A surface 7Ba of the second heat transfer section 7B constitutes a mounting surface on which the circuit board CB is placed.

[0022] In this embodiment, two electronic components E are arranged on the heat transfer member 7 (surface 7Aa). The electronic components E are arranged at a predetermined interval in the first direction D1. The electronic components E are electrically connected to the circuit board CB via terminals T. Here, in the following description, when the heat absorption structure 1 shown in FIG. 1 is viewed from the direction toward the heat transfer member 7 from the electronic components E side, a direction perpendicular to the first direction D1 is defined as a second direction D2.

[0023] The second insulating member 9 is a member that electrically insulates the electronic device 11 (heat transfer member 7) from the heat absorbing member 3. The second insulating member 9 is made of a resin having electrical insulation properties. The second insulating member 9 is made of, for example, PBT (polybutylene terephthalate) resin. The second insulating member 9 is an integrally molded product. The second insulating member 9 is provided between the electronic device 11 and a portion of the mounting surface 3a of the heat absorbing member 3 that is on the outer edge side of the first insulating member 5, at least in a portion where the creepage distance L between the electronic device 11 and the heat absorbing member 3, which is defined by the electronic device 11, the first insulating member 5, and the heat absorbing member 3, is the shortest.

[0024] In this embodiment, the second insulating member 9 has a frame shape. The second insulating member 9 is disposed around the first insulating member 5 so as to surround the entire circumference of the first insulating member 5. As shown in FIG. 2, the second insulating member 9 is placed on the mounting surface 3a of the heat absorbing member 3. The second insulating member 9 is placed on the outer edge of the mounting surface 3a. The second insulating member 9 has a portion facing the mounting surface 3a and the side surface 3b of the heat absorbing member 3. The second insulating member 9 protrudes outward from the mounting surface 3a of the heat absorbing member 3 in the first direction D1 or the second direction D2. That is, the second insulating member 9 protrudes outward from the mounting surface 3a over the entire circumference of the mounting surface 3a. The second insulating member 9 is, for example, fitted into the heat absorbing member 3.

[0025] The second insulating member 9 is solid when it is provided on the mounting surface 3a of the heat absorbing member 3. Being solid means that it does not have fluidity. In other words, being solid means that it does not have the property of changing its shape in an indefinite manner and can maintain a certain shape. In this embodiment, the second insulating member 9 has a certain hardness (strength) that can be maintained by an operator when it is attached to the heat absorbing member 3.

[0026] Next, a method for assembling (manufacturing) the heat absorption structure 1 will be described. First, the second insulating member 9 is attached to the heat absorption member 3. Next, the first insulating member 5 is formed on the heat absorption member 3. Specifically, a paste-like gap filler is applied to the mounting surface 3a of the heat absorption member 3 and cured. At this time, a part of the outer edge of the first insulating member 5 may be placed on the second insulating member 9. Next, the heat transfer member 7 is placed on the first insulating member 5. Thereafter, the circuit board CB is placed, and the electronic component E is placed on the heat transfer member 7. Note that the heat transfer member 7, the circuit board CB, and the electronic component E may be integrated in advance.

[0027] As described above, the heat absorbing structure 1 according to this embodiment includes the second insulating member 9. The second insulating member 9 is provided between the electronic device 11 and the electronic device 11 at a portion of the mounting surface 3a of the heat absorbing member 3 that is on the outer edge side of the first insulating member 5, and the electronic device 11. The second insulating member 9 is provided at a portion where the creeping distance L between the electronic device 11 and the heat absorbing member 3, which is determined by the electronic device 11, the first insulating member 5, and the heat absorbing member 3, is the shortest. In this way, when the first insulating member 5 formed by application is used in the heat absorbing structure 1, it is difficult to ensure the creeping distance between the electronic device 11 and the heat absorbing member 3 because it is difficult to control the shape. However, the second insulating member 9 can ensure the electrical insulation between the electronic device 11 and the heat absorbing member 3. In addition, in the heat absorbing structure 1, the second insulating member 9 can ensure the electrical insulation between the electronic device 11 and the heat absorbing member 3, so there is no need to enlarge the mounting surface 3a of the heat absorbing member 3. Therefore, it is possible to avoid the heat absorbing structure 1 from becoming large.

[0028] When an electronic device that includes a mixture of small electronic components such as the electronic component E and large electronic components such as a transformer and a capacitor is to be cooled by a single cooling mechanism, the electronic component E may have to be placed at a position away from the cooling mechanism. In this case, a heat absorbing member 3 is provided to efficiently absorb heat from the electronic component E. In order to miniaturize an electronic device having these electronic components, it is necessary to reduce the size of the heat absorbing member 3. If the size of the heat absorbing member 3 is reduced, the size of the mounting surface 3a of the heat absorbing member 3 also becomes smaller. In this case, when the first insulating member 5 is formed by a heat dissipation gap filler, it becomes difficult to ensure the creepage distance L between the electronic device 11 and the heat absorbing member 3, which is determined by the electronic device 11, the first insulating member 5, and the heat absorbing member 3.

[0029] In contrast, the heat absorption structure 1 of this embodiment is provided with the second insulating member 9, so that even if the size of the mounting surface 3a is reduced due to the miniaturization of the heat absorption member 3, the creepage distance L between the electronic device 11 and the heat absorption member 3, which is defined by the electronic device 11, the first insulating member 5, and the heat absorption member 3, can be secured.

[0030] In the heat absorption structure 1 according to this embodiment, the second insulating member 9 is disposed so as to surround the first insulating member 5. In this configuration, the first insulating member 5 is surrounded by the second insulating member 9 over the entire periphery, so that the electrical insulation between the electronic device 11 and the heat absorption member 3 can be further ensured.

[0031] In the heat absorption structure 1 according to this embodiment, the second insulating member 9 is an integrally molded product and has a frame shape. With this configuration, the second insulating member 9 can be easily attached to the heat absorption member 3.

[0032] [Second embodiment] Next, a second embodiment will be described. Fig. 3 is a cross-sectional view of a heat absorption structure according to the second embodiment. As shown in Fig. 3, a heat absorption structure 1A includes a heat absorption member 3, a first insulating member 5, a heat transfer member 7, and a second insulating member 13.

[0033] The second insulating member 13 has electrical insulation and thermal conductivity. The second insulating member 13 is formed of, for example, ceramic. The second insulating member 13 has a frame portion 13A and a bottom portion 13B. The frame portion 13A has the same shape as the second insulating member 9 of the first embodiment, is disposed around the first insulating member 5 so as to surround the entire periphery of the first insulating member 5, and is integrally formed with the first insulating member 5. The bottom portion 13B has a rectangular flat plate shape and is provided within an area surrounded by the inner peripheral surface of the frame portion 13A (in other words, the surface of the frame portion 13A on the first insulating member 5 side). The bottom portion 13B is disposed between the mounting surface 3a of the heat absorbing member 3 and the first insulating member 5. That is, the first insulating member 5 is mounted on the mounting surface 3a of the heat absorbing member 3 via the bottom portion 13B of the second insulating member 13. Being placed on the placement surface 3a may include a case where it is placed directly on (in contact with) the placement surface 3a, and a case where it is placed on the placement surface 3a via another member.

[0034] As described above, in the heat absorption structure 1A according to this embodiment, the second insulating member 13 has the bottom portion 13B disposed between the mounting surface 3a of the heat absorption member 3 and the first insulating member 5. In this configuration, the first insulating member 5 and the bottom portion 13B of the second insulating member 13 are disposed between the electronic device 11 and the heat absorption member 3, so that the electrical insulation between the electronic device 11 and the heat absorption member 3 can be further ensured.

[0035] Although the embodiment of the present invention has been described above, the present invention is not necessarily limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

[0036] In the above embodiment, the electronic device 11 is a MOSFET. However, the electronic device 11 may be other devices that generate heat when operated. The electronic device 11 may be, for example, a bipolar transistor, an IGBT (Insulated Gate Bipolar Transistor), or the like.

[0037] In the above embodiment, an example has been described in which two electronic components E are provided in the heat absorption structure 1. However, the number of electronic components E may be one, or three or more. Furthermore, a plurality of heat transfer members 7 may be arranged on the heat absorption member 3, and one or a plurality of electronic components E may be arranged on each of the plurality of heat transfer members 7.

[0038] In the above embodiment, the heat absorbing member 3 is a part of the heat sink. However, the heat absorbing member 3 may be provided separately. In this configuration, it is sufficient that a cooling mechanism is provided below the heat absorbing member 3.

[0039] In the above embodiment, the heat absorbing member 3 has a truncated pyramid shape as an example. However, the shape of the heat absorbing member 3 is not limited to this, and may be a truncated cone shape, a truncated pyramid shape, a cylindrical shape, a prismatic shape, or the like.

[0040] In the above embodiment, the second insulating members 9, 13 are frame-shaped and disposed around the first insulating member 5 so as to surround the first insulating member 5. However, the shape of the second insulating members 9, 13 is not limited. The second insulating members 9, 13 may be provided at least in a portion where the creepage distance between the electronic device 11 and the heat absorbing member 3, which is defined by the electronic device 11 (heat transfer member 7), the first insulating member 5, and the heat absorbing member 3, is shortest.

[0041] 2 and 3, the second insulating members 9, 13 have portions disposed opposite the mounting surface 3a and the side surface 3b of the heat absorbing member 3. However, it is sufficient that the second insulating member 9 has at least a portion disposed on the mounting surface 3a. In other words, the second insulating members 9, 13 do not need to have a portion opposed to the side surface 3b of the heat absorbing member 3.

[0042] In the above embodiment, the cross-sectional shape of the heat transfer member 7 is a convex shape. However, the shape of the heat transfer member 7 is not limited to this. The cross-sectional shape of the heat transfer member 7 may be a rectangular shape or the like.

[0043] In the above embodiment, the first insulating member 5 is a curable heat dissipating silicone gap filler. However, the first insulating member 5 may be a non-curable type. Furthermore, the first insulating member 5 is not limited to the heat dissipating silicone gap filler and may be another material. [Explanation of symbols]

[0044] 1...heat absorbing structure, 3...heat absorbing member, 3a...mounting surface, 5...first insulating member, 9, 13...second insulating member, 11...electronic device, 13B...bottom.

Claims

1. A heat absorption structure including a first insulating member having electrical insulation properties and thermal conductivity, and a protruding heat absorption member that absorbs heat generated by an electronic device provided on the first insulating member through the first insulating member, the heat absorbing member has a mounting surface on which the first insulating member and the electronic device are placed, the first insulating member is formed by being applied between the mounting surface and the electronic device, a second insulating member having electrical insulation properties and provided between the electronic device and a portion of the mounting surface on the outer edge side of the first insulating member, the second insulating member being provided at least in a portion where a creepage distance between the electronic device and the heat absorbing member, which is defined by the electronic device, the first insulating member, and the heat absorbing member, is shortest; The second insulating member is a solid when placed on the mounting surface.

2. The heat sink structure according to claim 1 , wherein the second insulating member is disposed so as to surround the first insulating member.

3. The heat sink structure according to claim 1 , wherein the second insulating member is disposed between the mounting surface and the first insulating member and has a bottom portion having thermal conductivity.

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