JPWO2020166584A1 - Heat dissipation body, heat dissipation structure and electronic equipment - Google Patents

Abstract

Provided is a heat radiating body which is excellent in heat radiating property and can suppress the radiation of unnecessary electromagnetic waves. A heat radiating body 1 made of a resin molded body, which is directly or indirectly thermally connected to a heat source 30 that generates an electromagnetic wave in a frequency band of 0.1 to 1000 MHz, and has a plate-shaped portion 2 having a main surface 2b. And a ground connection portion 4 which is provided so as to protrude from the main surface 2b of the plate-shaped portion 2 and is connected to the ground, and the heat conductivity in the in-plane direction of the radiator body 1 is 3 W / (. m · K) or more, and the volume resistance of the radiator body 1 is 1.0 × 10-2 Ω · cm or more and less than 1.0 × 108 Ω · cm.

Description

The present invention relates to a heat radiating body, and a heat radiating structure and an electronic device using the heat radiating body.

Conventionally, it is known that electronic components such as SoC (System-on-a-Chip) and LSI (Large Scale Integration) represented by GDC (Graphics Display Controller) generate heat during operation. Therefore, for the purpose of suppressing thermal runaway due to heat generation during operation, a radiator such as a heat sink is thermally connected to the electronic component, and exhaust heat treatment is performed.

For such a radiator, a metal such as an aluminum extruded plate having good thermal conductivity is generally used. However, since the radiator made of metal is also excellent in conductivity, when an electromagnetic field is generated from an electronic component existing in the vicinity, electromagnetic coupling may occur from the electronic component to the radiator. When an electromagnetic wave is generated from an electronic component to a radiator, the radiator functions as an antenna and unnecessary electromagnetic waves may be radiated. Therefore, the radiation of unnecessary electromagnetic waves from the radiator may cause problems such as EMI (Electromagnetic Interference).

The following Patent Document 1 discloses a resin heat sink in which a part or the whole is formed of a resin material. In the above resin material, the carbon material and the ceramic powder and / or the soft magnetic powder are uniformly dispersed in the resin. In Patent Document 1, the radiation of unnecessary electromagnetic waves is suppressed by forming the heat sink with a resin material having excellent electromagnetic shielding properties.

Further, Patent Document 2 below discloses a heat sink connector including a printed circuit board, an electronic component mounted on the printed circuit board, and a heat sink thermally connected to the electronic component. A metal member connected to the ground layer of the printed circuit board is arranged between the heat sink and the electronic component. Further, a heat conductive sheet having high resistance in the film thickness direction is arranged between the heat sink and the metal member. In Patent Document 2, electromagnetic noise is suppressed from being conducted to the heat sink by providing a metal member connected to the ground layer and a heat conductive sheet having high resistance in the film thickness direction. As a result, electromagnetic noise generated from the heat sink is suppressed.

Japanese Unexamined Patent Publication No. 2009-16415 Japanese Unexamined Patent Publication No. 2012-84499

However, the heat sink made of a resin material as in Patent Document 1 is still not sufficiently heat-dissipating. Further, the heat sink connector of Patent Document 2 has a problem that the number of parts such as a metal member and a heat conductive sheet is large. In particular, there is a problem that the manufacturing process becomes complicated when forming the metal member to be installed with the ground layer in the structure as in Patent Document 2.

An object of the present invention is to provide a heat radiating body which is excellent in heat radiating property and capable of suppressing the radiation of unnecessary electromagnetic waves, and a heat radiating structure and an electronic device using the heat radiating body.

In a wide range of aspects of the radiator according to the present invention, the radiator is used by being directly or indirectly thermally connected to a heat source that generates an electromagnetic wave in the frequency band of 0.1 to 1000 MHz, and is a radiator made of a resin molded body. A plate-shaped portion having a main surface and a ground connecting portion provided so as to project from the main surface of the plate-shaped portion and connected to the ground are provided, and heat conductivity in the in-plane direction of the radiator body is provided. Is 3 W / (m · K) or more, and the volume resistance of the radiator is 1.0 × 10 ⁻² Ω · cm or more and ^{less than 1.0 × 10 8} Ω · cm.

In another wide aspect of the radiator according to the present invention, it is a radiator made of a resin molded body, which is used by being directly or indirectly thermally connected to a heat source that generates an electromagnetic wave in a frequency band of 0.1 to 1000 MHz. A plate-shaped portion having a main surface is provided, the heat conductivity in the in-plane direction of the radiator is 3 W / (m · K) or more, and the volume resistance of the radiator is 1.0 × 10. ⁰ Omega · cm or more and less than 1.0 × 10 ⁶ Ω · cm.

In a specific aspect of the radiator according to the present invention, the thickness of the plate-shaped portion is 1.5 mm or more.

In another specific aspect of the radiator according to the present invention, the shape of the corner portion of the plate-shaped portion is an R shape.

In still another specific aspect of the radiator according to the present invention, the shape of the plate-shaped portion is a disk shape.

In yet another specific aspect of the radiator according to the present invention, the flame retardant level measured in accordance with the combustion standard UL94 is V1 or higher.

In yet another specific aspect of the radiator according to the present invention, a frame-shaped side wall portion provided on the main surface of the plate-shaped portion is further provided.

Yet another specific aspect of the radiator according to the present invention is a heat dissipation chassis, a heat dissipation housing, or a heat sink.

In still another specific aspect of the radiator according to the present invention, the radiator is a heat sink, having a first main surface and a second main surface with which the plate-shaped portions face each other. A ground connecting portion is provided on the main surface side of No. 1, and the plate-shaped portion and the ground connecting portion are integrally configured.

In still another specific aspect of the radiator according to the present invention, the fin portion of the heat sink is configured by providing a plurality of protrusions protruding from the plate-shaped portion on the second main surface side. The shape of the tip of the protruding portion constituting the fin portion is an R shape.

In still another specific aspect of the radiator according to the present invention, the plurality of protrusions are arranged in a dot shape to form the fin portion of the heat sink.

In yet another specific aspect of the radiator according to the present invention, the plurality of protrusions are arranged in a line and intermittently to form the fin portion of the heat sink.

In still another specific aspect of the radiator according to the present invention, the fin portions of the heat sink are configured by staggering the plurality of protrusions.

According to the present invention, the heat dissipation structure of the present invention is arranged on a substrate, a heat source provided on the substrate, and the heat source, and is directly or indirectly heat-connected to the heat source. It is provided with a heat radiating body to be configured.

In a specific aspect of the heat radiating structure of the present invention, a heat conductive sheet having a thermal conductivity in the thickness direction of 1 W / (m · K) or more is further provided, and the heat source and the heat radiating body are the heat conductive sheet. It is thermally connected via.

In another specific aspect of the heat dissipation structure of the present invention, the thickness of the heat conductive sheet is 0.5 mm or more.

In yet another specific aspect of the heat dissipation structure of the present invention, a heat spreader provided between the heat radiating body and the heat conductive sheet and different from the heat conductive sheet is further provided.

The electronic device according to the present invention includes a heat dissipation structure configured according to the present invention.

According to the present invention, it is possible to provide a heat radiating body which is excellent in heat radiating property and capable of suppressing the radiation of unnecessary electromagnetic waves, and a heat radiating structure and an electronic device using the heat radiating body.

FIG. 1A is a schematic plan view showing a heat radiating body and a heat radiating structure according to the first embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view taken along the line AA. Is. FIG. 2 is a schematic perspective view showing a heat radiating body according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a modified example of the joint structure between the substrate and the radiator. FIG. 4 is a schematic cross-sectional view showing a heat radiating body and a heat radiating structure according to a second embodiment of the present invention. FIG. 5 is a schematic perspective view showing a heat radiating body according to a third embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a heat dissipation structure according to a fourth embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a heat radiating body and a heat radiating structure according to a fifth embodiment of the present invention. FIG. 8 is a schematic perspective view showing a heat radiating body according to a sixth embodiment of the present invention. FIG. 9 is a schematic perspective view showing a heat radiating body according to a seventh embodiment of the present invention. FIG. 10 is a schematic perspective view showing a heat radiating body according to an eighth embodiment of the present invention.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Further, in the drawings, members having substantially the same function may be referred to by the same reference numeral.

(First Embodiment)
FIG. 1A is a schematic plan view showing a heat radiating body and a heat radiating structure according to the first embodiment of the present invention. FIG. 1B is a schematic cross-sectional view taken along the line AA of FIG. 1A. Further, FIG. 2 is a schematic perspective view showing a heat radiating body according to the first embodiment of the present invention.

As shown in FIGS. 1A and 1B, the heat dissipation structure 10 includes a substrate 20, a heat source 30, a heat conductive sheet 40, and a heat dissipation body 1.

The shape of the substrate 20 is not particularly limited, but in the present embodiment, it has a rectangular plate-like shape. A heat source 30 is mounted on the substrate 20. Therefore, the substrate 20 is a mounting substrate on which the heat source 30 is mounted. The substrate 20 is not particularly limited, and may be made of an appropriate material such as a metal plate, a ceramic plate, or a resin plate.

In the present embodiment, the heat source 30 is an LSI (Large Scale Integration). However, the heat source 30 is not particularly limited as long as it is a heat source 30 that generates an electromagnetic wave in a frequency band of 0.1 to 1000 MHz, and an appropriate electronic component or the like that generates such an electromagnetic wave can be used.

A heat conductive sheet 40 is provided on the heat source 30. It is desirable that the thermal conductivity sheet 40 has a thermal conductivity of 1 W / (m · K) or more in the thickness direction. The material of such a heat conductive sheet 40 is not particularly limited, but is, for example, a metal such as copper or aluminum, an alloy thereof, a conductive material such as a carbon material, or an alumina, boron nitride, or aluminum hydroxide. Examples thereof include insulating materials such as. The insulating material can be particularly preferably used when imparting insulating properties when it has a structure as in the fourth embodiment described later. Further, the heat conductive sheet 40 can also be suitably used as a cushioning material.

A heat radiating body 1 is provided on the heat conductive sheet 40. The heat radiating body 1 has a thermal conductivity of 3 W / (m · K) or more in the in-plane direction. The volume resistivity of the radiator 1 is 1.0 × ^10-2 Ω · cm or more and ^{less than 1.0 × 10 8} Ω · cm.

The thermal conductivity can be calculated using the following equation (1).

Thermal conductivity (W / (m · K)) = specific gravity (g / cm ³ ) x specific heat (J / g · K) x thermal diffusivity (mm ² / s) ... Equation (1)

The thermal diffusivity can be measured using, for example, a product number "xenon flash laser analyzer LFA467 HyperFlash" manufactured by Netch Japan Co., Ltd.

The thermal conductivity of the radiator 1 in the in-plane direction is preferably 5 W / (m · K) or more, more preferably 10 W / (m · K) or more. The upper limit of the thermal conductivity in the in-plane direction is not particularly limited, but may be, for example, 50 W / (m · K).

The thermal conductivity in the thickness direction of the radiator 1 is not particularly limited, but is preferably 1 W / (m · K) or more, preferably 10 W / (m · K) or less.

Further, the resistivity can be calculated from the resistivity correction coefficient and the thickness of the resin molded body by measuring the resistivity value using a low resistivity resistor meter. For example, it can be measured at room temperature and in the atmosphere by a four-probe method resistivity measuring device (Loresta AX MCP-T370, manufactured by Mitsubishi Chemical Corporation).

The volume resistivity of the radiator 1 is preferably 1.0 × 10 ⁷ Ω · cm or less, and more preferably 1.0 × 10 ⁵ Ω · cm or less.

Further, the flame retardancy level measured in accordance with the combustion standard UL94 of the radiator body 1 is preferably V1 or higher.

In the present embodiment, the heat radiating body 1 is a heat sink. The heat radiating body 1 includes a plate-shaped portion 2, a protruding portion 3, a ground connecting portion 4, a heat conductive sheet connecting portion 5, and a joining portion 6. The heat radiating body 1 is a resin molded body in which a plate-shaped portion 2, a protruding portion 3, a ground connecting portion 4, a heat conductive sheet connecting portion 5, and a joining portion 6 are integrally configured. In particular, it is preferable that the plate-shaped portion 2, the protruding portion 3, the ground connecting portion 4, the heat conductive sheet connecting portion 5, and the joining portion 6 are integrally molded. However, the plate-shaped portion 2, the protruding portion 3, the ground connecting portion 4, the heat conductive sheet connecting portion 5, and the joint portion 6 may not be integrally configured, and some of them may be integrally configured. ..

The shape of the plate-shaped portion 2 is not particularly limited, but in the present embodiment, it is a substantially rectangular plate-shaped portion. The plate-shaped portion 2 has a first main surface 2a and a second main surface 2b facing each other. In the present embodiment, a plurality of projecting portions 3 are configured so as to project from the second main surface 2b of the plate-shaped portion 2, thereby forming a fin portion of the heat sink. More specifically, a plurality of projecting portions 3 extending linearly from one end 2c of the plate-shaped portion 2 toward the other end 2d are provided, thereby forming a fin portion. The pitch of the protruding portions 3 constituting the fin portions is not particularly limited and may be, for example, 1 mm to 50 mm. The height of the protrusion 3 is not particularly limited and may be, for example, 1 mm to 500 mm. The width of the protrusion 3 is not particularly limited and may be 0.5 mm to 50 mm.

The heat radiating body 1 may be a heat radiating body different from the heat sink. Therefore, the plurality of protrusions 3 may not be provided. The heat radiating body 1 may be a flat plate-shaped heat radiating plate composed of the plate-shaped portion 2.

On the first main surface 2a side of the plate-shaped portion 2, a plurality of ground connecting portions 4, a heat conductive sheet connecting portion 5, and a plurality of joining portions 6 are provided. The ground connecting portion 4, the heat conductive sheet connecting portion 5, and the joining portion 6 are provided so as to project from the first main surface 2a side of the plate-shaped portion 2.

The ground connection portion 4 is connected to the ground of the substrate 20. The shape of the ground connection portion 4 is not particularly limited, but in the present embodiment, it has a substantially columnar shape. However, the shape of the ground connection portion 4 is not particularly limited as long as it has the function of being ground-connected.

The joint portion 6 is joined to the joint hole 21 of the substrate 20. In the present embodiment, the heat radiating body 1 and the substrate 20 are joined by fitting the hook-shaped joint portion 6 into the joining hole 21 of the substrate 20.

The heat conductive sheet connecting portion 5 has a tapered shape. The area of the heat conductive sheet connecting portion 5 increases as it approaches the plate-shaped portion 2. By providing such a connection portion, the heat generated from the heat source 30 can be more efficiently diffused by the heat radiating body 1. However, the shape of the heat conductive sheet connecting portion 5 is not particularly limited. Further, the heat conductive sheet connecting portion 5 may not be provided.

In the heat radiating structure 10 configured in this way, the heat source 30 and the heat radiating body 1 are indirectly heat-connected via the heat conductive sheet, so that the heat generated from the heat source 30 is efficiently transferred from the heat radiating body 1. Can be released. Further, since the heat radiating body 1 is ground-connected by the ground connecting portion 4, electromagnetic noise from the heat source 30 to the heat radiating body 1 can be guided to the ground side. Therefore, it is difficult for the heat radiating body 1 to function as an antenna, and it is possible to suppress the emission of unnecessary electromagnetic waves from the heat radiating body 1.

Further, the heat radiating body 1 is made of a resin molded body. Therefore, the plate-shaped portion 2, the protruding portion 3, the ground connecting portion 4, the heat conductive sheet connecting portion 5, and the joining portion 6 can be integrally configured. Therefore, the number of parts can be reduced and the manufacturing is easy as compared with the case where the heat radiating body 1 is made of metal.

In the present embodiment, the corner portion 2e of the plate-shaped portion 2 in the radiator body 1 shown in FIG. 1A has an R shape. The tips 3a of the plurality of protrusions 3 in the heat radiating body 1 shown in FIG. 1B have an R shape. Further, the corner portion 5a of the heat conductive sheet connecting portion 5 in the heat radiating body 1 shown in FIG. 2 has an R shape.

As described above, when the corners of the members constituting the heat radiating body 1 have an R shape, the heat radiating body 1 is more difficult to function as an antenna, and it is possible to further suppress the emission of unnecessary electromagnetic waves. can. Further, in this case, the R of the corner portion is preferably 1 or more. In this case, the heat radiating body 1 is more difficult to function as an antenna, and it is possible to further suppress the emission of unnecessary electromagnetic waves. The upper limit of R at the corner is not particularly limited, but may be, for example, 10. However, a part of the corners of each member constituting the radiator 1 may be R-shaped, and all the corners of the radiator 1 may not be R-shaped.

The thickness of the plate-shaped portion 2 constituting the heat radiating body 1 is not particularly limited, but is preferably 1.5 mm or more. In this case, the moldability and heat dissipation of the heat radiating body 1 can be further improved. The upper limit of the thickness of the plate-shaped portion 2 constituting the heat radiating body 1 is not particularly limited, but may be, for example, 6 mm.

Further, in the present embodiment, the adhesion between the heat radiating body 1 and the substrate 20 is enhanced by fitting the hook-shaped joint portion 6 constituting the heat radiating body 1 into the joining hole 21 of the substrate 20. Therefore, the ground connection portion 4 can be more reliably connected to the ground of the substrate 20. The joint portion 6 does not have to have a hook-like shape. Further, when it is desired to further improve the adhesion, the heat radiating body 1 and the substrate 20 may be bonded by the screw 6A as in the modified example of the bonding structure shown in FIG. 3, and the adhesion may be enhanced. However, the joint portion 6 may not be provided, and the adhesiveness between the radiator body 1 and the substrate 20 may not be enhanced by the joint portion 6.

The thickness of the heat conductive sheet 40 is not particularly limited, but is preferably 0.5 mm or more. The upper limit of the thickness of the heat conductive sheet 40 is not particularly limited and may be 6 mm.

The heat radiating body 1 of the present embodiment can reduce the number of parts, has excellent heat radiating properties, and can suppress the radiation of unnecessary electromagnetic waves. Therefore, as in the present embodiment, it can be suitably used as a heat radiating body for electronic components such as LSI (Large Scale Integration). Therefore, it can also be used as an electronic device provided with such an electronic component.

However, the radiator 1 of the present embodiment is a housing of a communication device used indoors or outdoors, an electronic device such as a security camera or a smart meter, a multi-information display such as a car navigation system or a smart meter, or a heat dissipation chassis of an in-vehicle camera. It can also be used for such purposes. Among them, the heat radiating body 1 is preferably a heat radiating chassis, a heat radiating housing, or a heat sink. However, the heat radiating body 1 may be used for the liquid crystal display module.

(Second embodiment)
FIG. 4 is a schematic cross-sectional view showing a heat radiating body and a heat radiating structure according to a second embodiment of the present invention. As shown in FIG. 4, the heat radiating structure 50 is not provided with the heat conductive sheet 40. Further, in the heat radiating body 51, instead of the heat conductive sheet connecting portion 5, a heat source connecting portion 52 having the same structure as the heat conductive sheet connecting portion 5 is provided. Then, in the heat radiating body 51, the heat source connecting portion 52 is connected to the heat source 30. Therefore, the heat radiating body 51 and the heat source 30 are directly thermally connected. Other points are the same as those of the first embodiment.

In the heat radiating structure 50 configured in this way, since the heat source 30 and the heat radiating body 51 are directly thermally connected, the heat generated from the heat source 30 can be efficiently discharged from the heat radiating body 51. Further, since the heat radiating body 51 is ground-connected by the ground connecting portion 4, electromagnetic noise from the heat source 30 to the heat radiating body 51 can be guided to the ground side. Therefore, it is difficult for the heat radiating body 51 to function as an antenna, and it is possible to suppress the emission of unnecessary electromagnetic waves from the heat radiating body 51.

Further, the heat radiating body 51 is made of a resin molded body. Therefore, the plate-shaped portion 2, the protruding portion 3, the ground connecting portion 4, the heat source connecting portion 52, and the joint portion 6 can be integrally configured. Therefore, the number of parts can be reduced and the manufacturing is easy as compared with the case where the heat radiating body 51 is made of metal.

As in the second embodiment, the heat conductive sheet 40 may not be provided. However, from the viewpoint of further enhancing the heat dissipation property, it is preferable that the heat conductive sheet 40 is provided as in the heat dissipation structure 10 of the first embodiment.

(Third embodiment)
FIG. 5 is a schematic perspective view showing a heat radiating body according to a third embodiment of the present invention. As shown in FIG. 5, in the heat radiating body 61, the shape of the plate-shaped portion 62 is a disk shape. Further, the plurality of protrusions 63 have a columnar shape. The fin portion of the heat sink is configured by providing the plurality of projecting portions 63 so as to project from the second main surface 62b of the plate-shaped portion 62. The heat conductive sheet connecting portion 65 also has a disk-shaped shape. Other points are the same as those of the first embodiment.

Also in the third embodiment, the heat source 30 and the radiator 61 are directly or indirectly thermally connected. Therefore, the heat generated from the heat source 30 can be efficiently discharged from the radiator body 61. Since the heat radiating body 61 is ground-connected by the ground connecting portion 64, electromagnetic noise from the heat source 30 to the heat radiating body 61 can be guided to the ground side. Therefore, it is difficult for the heat radiating body 61 to function as an antenna, and it is possible to suppress the emission of unnecessary electromagnetic waves from the heat radiating body 61.

Further, the heat radiating body 61 is made of a resin molded body. Therefore, the plate-shaped portion 62, the protruding portion 63, the ground connecting portion 64, the heat conductive sheet connecting portion 65, and the joint portion 6 (not shown) can be integrally configured. Therefore, the number of parts can be reduced and the manufacturing is easy as compared with the case where the heat radiating body 61 is made of metal.

As in the third embodiment, the plate-shaped portion 62 may be in the shape of a disk, and the shape is not particularly limited. The plurality of protrusions 63 may also be columnar, and the shape is not particularly limited. Further, the heat conductive sheet connecting portion 65 may also have a columnar shape, and the shape is not particularly limited. Further, the heat conductive sheet connecting portion 65 may not be provided, and the heat source 30 may be directly connected to the plate-shaped portion 62.

(Fourth Embodiment)
FIG. 6 is a schematic cross-sectional view showing a heat dissipation structure according to a fourth embodiment of the present invention.

As shown in FIG. 6, the heat dissipation structure 70 is not provided with the ground connection portion 4 and the joint portion 6. The thermal conductivity of the radiator 71 in the in-plane direction is 3 W / (m · K) or more. The volume resistivity of the heat sink 71, 1.0 × 10 ⁰ Ω · cm or more and less than 1.0 × 10 ⁶ Ω · cm. Other points are the same as those of the first embodiment.

Also in the fourth embodiment, since the heat source 30 and the radiator 71 are thermally connected via the heat conductive sheet 40, the heat generated from the heat source 30 is transferred from the radiator 71 having a high thermal conductivity as described above. It can be released efficiently.

Further, as in the fourth embodiment, the ground connection portion 4 may not be provided, and the number of ground connection portions 4 may be reduced.

Conventionally, when the radiator is made of metal, the radiator functions as an antenna even when the ground connection portion is provided, and unnecessary electromagnetic waves may be radiated from the radiator.

On the other hand, since the heat radiating body 71 is composed of a resin molded body and the volume resistance is equal to or higher than the above lower limit value, it is difficult for the heat radiating body 71 to function as an antenna, and unnecessary electromagnetic waves are radiated from the heat radiating body 71. It can be suppressed from being done.

Further, since the number of the ground connection portions 4 can be reduced, the number of parts can be reduced and the manufacturing is easy as compared with the case where the radiator 71 is made of metal.

(Fifth Embodiment)

FIG. 7 is a schematic cross-sectional view showing a heat radiating body and a heat radiating structure according to a fifth embodiment of the present invention.

As shown in FIG. 7, in the heat radiating body 81 constituting the heat radiating structure 80, a frame-shaped side wall portion 82 is provided so as to project from the outer peripheral edge of the main surface 2a in the plate-shaped portion 2. Further, the heat radiating structure 80 further includes a heat spreader 83 provided between the heat radiating body 81 and the heat conductive sheet 40. The heat spreader 83 is provided on the entire surface of the first main surface 2a of the plate-shaped portion 2 of the radiator body 81. The heat spreader 83 is a member different from the heat conductive sheet 40. The heat spreader 83 is made of aluminum in this embodiment. However, it may be composed of other metals or alloys such as copper, and the material is not particularly limited. Other points are the same as those of the fourth embodiment.

Also in the fifth embodiment, since the heat source 30 and the radiator 81 are thermally connected via the heat conductive sheet 40 and the heat spreader 83, the heat generated from the heat source 30 has high thermal conductivity as described above. It can be efficiently discharged from the radiator 81. In this case, the heat conductive sheet 40 may not be provided, and the heat source 30 and the radiator 81 may be thermally connected only via the heat spreader 83. Even in that case, the heat generated from the heat source 30 can be efficiently discharged from the radiator 81 having high thermal conductivity as described above.

Further, since the volume resistivity is at least the above lower limit value, it is difficult for the heat radiating body 81 to function as an antenna, and it is possible to suppress the emission of unnecessary electromagnetic waves from the heat radiating body 81. Further, in the present embodiment, the frame-shaped side wall portion 82 is provided so as to project from the outer peripheral edge of the main surface 2a in the plate-shaped portion 2, and has a shield BOX shape. Therefore, the radiation of unnecessary electromagnetic waves can be further suppressed.

Further, since the number of the ground connection portions 4 can be reduced, the number of parts can be reduced and the manufacturing is easy as compared with the case where the radiator 81 is made of metal.

In the present embodiment, the frame-shaped side wall portion 82 and the heat spreader 83 are applied to the fourth embodiment, but the frame-shaped side wall portion 82 and the heat spreader 83 are applied to the first to third embodiments. May be applied.

(6th to 8th embodiments)
FIG. 8 is a schematic perspective view showing a heat radiating body according to a sixth embodiment of the present invention.

As shown in FIG. 8, in the heat radiating body 91, a plurality of protruding portions 93 are arranged in a dot shape to form a fin portion of a heat sink. In the heat radiating body 91, the planar shape of the protruding portion 93 is substantially elliptical. Further, the three-dimensional shape of the protruding portion 93 is a semi-elliptical spherical shape. However, the three-dimensional shape of the protruding portion 93 is not limited to such a dome shape, and may be a shape like an elliptical frustum.

In particular, in the present embodiment, the fin portions of the heat sink are configured by arranging the plurality of protruding portions 93 in a staggered manner. Specifically, the protrusions 93 are arranged at regular intervals in the direction along the major axis of the ellipse. With this as one column, a plurality of columns are provided in parallel. Further, when viewed from a direction orthogonal to the plurality of rows, the protruding portion 93 of one of the adjacent rows is provided so as to close the gap between the protruding portions 93 of the other row. Other points are the same as those of the first embodiment.

FIG. 9 is a schematic perspective view showing a heat radiating body according to a seventh embodiment of the present invention.

As shown in FIG. 9, in the radiator 101, the planar shape of the protruding portion 103 constituting the fin portion is substantially circular. Further, the three-dimensional shape of the protruding portion 103 is a truncated cone shape. However, the shape of the protrusion 103 is not limited to such a shape, and may be a dome shape such as a hemisphere. Other points are the same as those of the sixth embodiment.

FIG. 10 is a schematic perspective view showing a heat radiating body according to an eighth embodiment of the present invention.

As shown in FIG. 10, in the heat radiating body 111, a plurality of protruding portions 113 are arranged in a line shape and intermittently to form a fin portion of a heat sink. Further, also in the heat radiating body 111, the plurality of protruding portions 113 are arranged in a staggered manner. Specifically, a plurality of rows are provided in parallel with the plurality of protrusions 113 arranged in a line and intermittently as one row. Further, when viewed from a direction orthogonal to the plurality of rows, the protruding portion 113 of one of the adjacent rows is provided so as to close the gap between the protruding portions 113 of the other row. Further, the tip shape of the plurality of protrusions 113 is an R shape. Other points are the same as those of the first embodiment.

Also in the sixth to eighth embodiments, the heat generated from the heat source can be efficiently discharged from the radiator. In addition, it is difficult for the radiator to function as an antenna, and it is possible to suppress the emission of unnecessary electromagnetic waves from the radiator. Further, since the heat radiating body is made of a resin molded body, the number of parts can be reduced and the manufacturing is easy as compared with the case where the heat radiating body is made of metal.

As in the sixth to eighth embodiments, the fin portions of the heat sink may be configured by arranging the plurality of protruding portions in a dot shape, a line shape, and intermittently. Further, the plurality of protrusions may be staggered. In particular, when viewed from a direction orthogonal to a plurality of rows, the protrusions of one of the adjacent rows may be provided so as to close the gap between the protrusions of the other row. In this case, it is possible to more reliably suppress the emission of unnecessary electromagnetic waves from the radiator.

Hereinafter, the details of the resin molded body constituting the heat radiating body of the present invention will be described.

(Resin molded product)
The heat radiating body of the present invention is made of a resin molded body. The thermal conductivity of the resin molded product in the in-plane direction is 3 W / (m · K) or more. The volume resistivity of the resin molded product is 1.0 × ^10-2 Ω · cm or more and ^{less than 1.0 × 10 8} Ω · cm. Therefore, the heat radiating body made of such a resin molded body can enhance both heat radiating property and conductivity.

Further, in the present invention, it is preferable that the flame retardancy level measured in accordance with the combustion standard UL94 of the resin molded product is V1 or higher. In this case, the flame retardancy of the heat radiating body made of such a resin molded body can be enhanced.

The thermal conductivity, volume resistivity and flame retardancy of the radiator can be the same as the thermal conductivity, volume resistivity and flame retardancy of the resin molded body constituting the radiator.

Hereinafter, an example of the composition of such a resin molded product will be described. However, the composition of the resin molded product is not particularly limited as long as the thermal conductivity and the volume resistivity satisfy the above ranges.

In the present invention, as the resin molded body, for example, a molded body of a resin composition containing a thermoplastic resin and carbon black and plate-like graphite can be used. Such a resin molded body can be obtained by molding the resin composition by, for example, a method such as press processing, extrusion processing, extrusion laminating processing, or injection molding.

By forming a resin molded body containing both a thermoplastic resin and carbon black and plate-like graphite, it is possible to improve all of heat dissipation, conductivity, and flame retardancy.

However, in the present invention, it may be a resin molded product containing a thermoplastic resin and plate-like graphite. Therefore, the resin molded product does not have to contain carbon black. In this case, it is easier to adjust by the range of thermal conductivity and volume resistivity as in the radiator of the fourth embodiment described above. Further, the resin molded body may further contain expanded graphite different from the plate-shaped graphite.

Thermoplastic resin;
The thermoplastic resin is not particularly limited, and known thermoplastic resins can be used. Specific examples of the thermoplastic resin include polyolefin, polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile, polyester, polyamide, polyurethane, polyether sulfone, polyether ketone, polyimide, polydimethylsiloxane, polycarbonate, or at least two of them. Examples include a copolymer containing seeds. These thermoplastic resins may be used alone or in combination of two or more.

The thermoplastic resin is preferably a resin having a high elastic modulus. Polyolefins are more preferred because they are inexpensive and easy to mold under heating.

The polyolefin is not particularly limited, and known polyolefins can be used. Specific examples of the polyolefin include polyethylene which is an ethylene homopolymer, ethylene-α-olefin copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-acetic acid. Examples thereof include polyethylene-based resins such as vinyl copolymers. The polyolefin is a polypropylene resin such as polypropylene which is a propylene homopolymer or a propylene-α-olefin copolymer, or a homopolymer or copolymer of a conjugated diene such as polybutene, butadiene or isoprene which is a butene homopolymer. And so on. These polyolefins may be used alone or in combination of two or more. From the viewpoint of further increasing heat resistance and elastic modulus, polypropylene is preferable as the polyolefin.

Further, the polyolefin (olefin resin) preferably contains an ethylene component. The content of the ethylene component is preferably 5% by mass to 40% by mass. When the content of the ethylene component is within the above range, the impact resistance of the resin molded product can be further enhanced, and the heat resistance can be further enhanced.

Carbon black;
As the carbon black, for example, oil furnace black such as Ketjen black, acetylene black, channel black, thermal black and the like can be used. Of these, oil furnace black is preferable from the viewpoint of further enhancing the conductivity of the resin molded product. Further, carbon black may contain metal impurities such as Fe and Ni.

The amount of DBP oil absorbed by carbon black is not particularly limited, but is preferably 160 ml / 100 g or more, preferably 200 ml / 100 g or more, 800 ml / 100 g or less, preferably 500 ml / 100 g or less, and more preferably 400 ml / 100 g or less. .. When the DBP oil absorption amount of carbon black is at least the above lower limit, the conductivity and flame retardancy of the resin molded product can be further enhanced. When the DBP oil absorption amount of carbon black is not more than the above upper limit, it is possible to prevent agglomeration during kneading and further improve the stability.

The DBP oil absorption of carbon black can be measured according to JIS K 6217-4. The DBP oil absorption amount can be measured using, for example, an absorption amount measuring device (manufactured by Asahi Soken Co., Ltd., product number "S-500").

The content of carbon black is preferably 10 parts by weight or more, more preferably 15 parts by weight or more, still more preferably 20 parts by weight or more, and preferably 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin. It is less than or equal to, more preferably 80 parts by weight or less, still more preferably 50 parts by weight or less. When the content of carbon black is at least the above lower limit, the conductivity and flame retardancy can be further enhanced. Further, when the content of carbon black is not more than the above upper limit, the balance between conductivity, flame retardancy and impact resistance can be further improved.

The primary particle size of carbon black is preferably 40 nm or more, preferably 50 nm or less, and more preferably 45 nm or less. When the primary particle size of carbon black is within the above range, higher conductivity and flame retardancy can be obtained with a lower concentration of carbon black.

The primary particle size of carbon black is, for example, an average primary particle size obtained by using image data of carbon black obtained by a transmission electron microscope. As the transmission electron microscope, for example, a product name "JEM-2200FS" manufactured by JEOL Ltd. can be used.

Plate graphite;
The plate-shaped graphite is not particularly limited as long as it is plate-shaped graphite, and for example, graphite, flaky graphite, graphene, or the like can be used. From the viewpoint of further enhancing flame retardancy and thermal conductivity, graphite or flaky graphite is preferable. These may be used alone or in combination of two or more. As the graphite, for example, scaly graphite can be used. From the viewpoint of further enhancing the flame retardancy, expanded graphite may be used.

The flaky graphite is obtained by exfoliating the original graphite, and refers to a graphene sheet laminate thinner than the original graphite. The exfoliation treatment for forming flaky graphite is not particularly limited, and either a mechanical exfoliation method using a supercritical fluid or a chemical exfoliation method using an acid may be used. The number of graphene sheets laminated in the flaky graphite may be smaller than that of the original graphite, but is preferably 1000 layers or less, more preferably 500 layers or less, and further preferably 200 layers or less.

The volume average particle size of the plate graphite is preferably 5 μm or more, more preferably 40 μm or more, still more preferably 100 μm or more, particularly preferably 200 μm or more, preferably 500 μm or less, more preferably 350 μm or less, still more preferably 300 μm or less. be. When the volume average particle size of the plate-shaped graphite is at least the above lower limit, the heat dissipation can be further improved. In particular, even when carbon black is not contained, the conductivity and heat dissipation can be adjusted in a more suitable range. On the other hand, when the volume average particle size of the plate-shaped graphite is not more than the above upper limit, the flame retardancy of the resin molded product can be further enhanced. Two or more types of plate graphite having different volume average particle diameters may be used in combination.

Further, in the present invention, the volume average particle size of the plate-shaped graphite is calculated by a volume reference distribution by a laser diffraction method using a laser diffraction / scattering type particle size distribution measuring device in accordance with JIS Z 8825: 2013. The value.

For example, plate-like graphite is put into a soap aqueous solution (neutral detergent: containing 0.01%) so that its concentration becomes 2% by weight, and ultrasonic waves are irradiated at an output of 300 W for 1 minute using an ultrasonic homogenizer. , Get a suspension. Next, the volumetric particle size distribution of the plate-like graphite is measured for the suspension by a laser diffraction / scattering type particle size analysis measuring device (manufactured by Nikkiso Co., Ltd., product name “Microtrac MT3300”). A value of 50% of the cumulative volume particle size distribution can be calculated as the volume average particle size of the plate-shaped graphite.

The content of the plate graphite is preferably 10 parts by weight or more, preferably 70 parts by weight or more, more preferably 100 parts by weight or more, and preferably 200 parts by weight or less, more preferably 200 parts by weight or more, based on 100 parts by weight of the thermoplastic resin. Is 180 parts by weight or less, more preferably 150 parts by weight or less. When the content of plate graphite is at least the above lower limit, the conductivity, flame retardancy and heat dissipation can be further enhanced. Further, if the content of the plate graphite is too large, the area of the interface that is the starting point of fracture becomes large. Therefore, when the content of the plate graphite is not more than the above upper limit, the impact resistance can be further improved. ..

The aspect ratio of the plate graphite is preferably 5 or more, more preferably 21 or more, preferably 2000 or less, more preferably 1000 or less, still more preferably 100 or less. When the aspect ratio of the plate-shaped graphite is at least the above lower limit, the heat dissipation in the plane direction can be further improved. Further, when the aspect ratio of the plate-shaped graphite is not more than the above upper limit, for example, the graphite particles themselves are less likely to bend in the thermoplastic resin during injection molding. Therefore, the gas barrier performance can be further improved and the flame retardancy can be further improved. In the present specification, the aspect ratio means the ratio of the maximum dimension of the plate-shaped graphite to the thickness of the plate-shaped graphite in the direction of the laminated surface.

The shape and thickness of the plate-shaped graphite can be measured using, for example, a transmission electron microscope (TEM) or a scanning electron microscope (SEM). From the viewpoint of making it easier to observe, it is desirable to heat the test piece cut out from the resin molded body at 600 ° C. to remove the resin and observe it with a transmission electron microscope (TEM) or a scanning electron microscope (SEM). .. The test piece may be cut out along the direction along the main surface of the resin molded body as long as the thickness of the plate-shaped graphite can be measured by skipping the resin, or along the direction orthogonal to the main surface of the resin molded body. You may cut it out.

Fiber-based filler;
The resin molded product may further contain a fiber-based filler. Examples of the fiber-based filler include metal fibers, carbon fibers, cellulose fibers, aramid fibers and glass fibers. These may be used alone or in combination of two or more.

The content of the fiber-based filler is not particularly limited, but is preferably 1 part by weight or more and 200 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin. When the content of the fiber-based filler is within the above range, more excellent fluidity can be imparted to the resin composition when forming the resin molded product.

The carbon fiber is not particularly limited, but PAN-based or pitch-based carbon fiber or the like can be used.

Flame retardants;
The resin molded product may contain other flame retardants. Other flame retardants include, but are not limited to, bromine compounds, phosphorus compounds, chlorine compounds, antimony compounds, metal hydroxides, nitrogen compounds, boron compounds and the like.

The content of the other flame retardant in the resin molded product is not particularly limited, but is preferably 10 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin, for example. When the content of the other flame retardant is not more than the above upper limit, it is more preferable from the environmental aspect.

However, by using both plate-like graphite and carbon black, high flame retardancy can be obtained even when a halogen-based flame retardant or a phosphorus-based flame retardant is not contained or a small amount is added. When used in combination with a flame retardant, even higher flame retardancy can be obtained as compared with the case where the flame retardant is used alone.

Other additives;
Various additives may be added as optional components to the resin molded product. Additives include, for example, phenolic, phosphorus, amine, sulfur and other antioxidants; benzotriazole, hydroxyphenyltriazine and other UV absorbers; metal damage inhibitors; various fillers; antistatic agents. ; Stabilizers; pigments and the like. These may be used alone or in combination of two or more.

It is desirable that the resin molded product of the present invention contains substantially no magnetic material. In the present invention, substantially not contained means that it is 10% by weight or less in the resin molded product. The magnetic material is not particularly limited as long as it is a material having soft magnetism. A material having soft magnetism is a material that is strongly magnetized under the influence of a magnetic field but has no magnetic force in an environment that is not affected by a magnetic field. As the magnetic material, for example, metal alloys such as ferrite, sendust, and permalloy can be used.

(Manufacturing method of resin molded product)
The resin molded product can be produced, for example, by the following method.

For example, a resin composition containing a thermoplastic resin, plate-like graphite, and carbon black is prepared. The various materials described above may be further contained in the resin composition. In the resin composition, it is preferable that carbon black is dispersed in the thermoplastic resin. In this case, the conductivity of the obtained resin molded product can be further enhanced. The method for dispersing carbon black or plate graphite in the thermoplastic resin is not particularly limited, but the thermoplastic resin is heated and melted and kneaded with carbon black or plate graphite to disperse it more uniformly. Can be done.

The above kneading method is not particularly limited, but is heated by using, for example, a kneading device such as a twin-screw kneader such as a plast mill, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, or a pressurized kneader. There is a method of kneading in. Among these, the method of melt-kneading using an extruder is preferable.

Next, the prepared resin composition can be molded by a method such as press working, extrusion processing, extrusion laminating processing, or injection molding to obtain a resin molded body having a desired shape.

As described above, in the resin molded product, the physical properties can be appropriately adjusted according to the intended use. For example, a resin molded product having a desired volume resistivity and thermal conductivity can be obtained as in the following examples. The following examples are examples of manufacturing a resin molded body constituting a heat radiating body, and the present invention is not limited to the following examples.

(Example 1)
100 parts by weight of polypropylene (PP) as a thermoplastic resin, 50 parts by weight of oil furnace black as carbon black, and 100 parts by weight of scaly graphite as plate graphite are provided in Laboplast Mill (manufactured by Toyo Seiki Co., Ltd.) A resin composition was obtained by melt-kneading at 200 ° C. using R100 ”). The obtained resin composition was injection-molded at a temperature of 230 ° C. of the resin composition and a temperature of 40 ° C. of a mold to obtain a resin molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. As polypropylene, a product name "BC10HRF" manufactured by Japan Polypropylene Corporation was used. As the oil furnace black, a trade name "EC200L" manufactured by Lion Co., Ltd. (DBP oil absorption amount: 300 ml / 100 g, primary particle size: 41 nm) was used. As the scaly graphite, a trade name “CPB-100” (average particle size: 100 μm) manufactured by Chuetsu Graphite Industry Co., Ltd. was used.

The thermal conductivity of the obtained resin molded body in the in-plane direction was 12.7 W / (m · K), and the volume resistivity was 8.1 × 10 ⁻² Ω · cm. No flame retardancy was applicable in the UL94 V test.

The in-plane thermal conductivity (in-plane thermal conductivity) was measured using a product number "xenon flash laser analyzer LFA467 HyperFlash" manufactured by Netch Japan. Specifically, a resin molded body molded into a length of 100 mm, a width of 100 mm, and a thickness of 2 mm was punched into a length of 10 mm, a width of 2 mm, and a thickness of 2 mm to prepare a measurement sample. The measurement sample was fitted into the holder in an direction in which the in-plane thermal conductivity could be measured, the thermal diffusivity at 30 ° C. was measured, and the thermal conductivity was calculated according to the following formula (1).

Thermal conductivity (W / (m · K)) = specific gravity (g / cm ³ ) x specific heat (J / g · K) x thermal diffusivity (mm ² / s) ... Equation (1)

The volume resistivity was measured at room temperature and in the atmosphere by a four-probe method resistivity measuring device (Loresta AX MCP-T370, manufactured by Mitsubishi Chemical Corporation).

For flame retardancy, a test piece is prepared by cutting a resin molded body into a rectangular shape in a plan view into a length of 125 mm, a width of 13 mm, and a thickness of 1.5 mm, and the test piece (resin molded body) is burned. Sex was evaluated according to the UL94 V test. The UL94 V test was evaluated with V0, V1 and V2, and those that did not apply were described as not applicable.

(Example 2)
100 parts by weight of polypropylene (PP) as a thermoplastic resin and 100 parts by weight of scaly graphite as plate-like graphite are melted at 200 ° C. using a laboplast mill (manufactured by Toyo Seiki Co., Ltd., product number "R100"). A resin composition was obtained by kneading. The obtained resin composition was injection-molded at a temperature of 230 ° C. of the resin composition and a temperature of 40 ° C. of a mold to obtain a resin molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. As polypropylene, a product name "BC10HRF" manufactured by Japan Polypropylene Corporation was used. As the scaly graphite, a trade name "CPB-300" (average particle size: 300 μm) manufactured by Chuetsu Graphite Industry Co., Ltd. was used.

The thermal conductivity of the obtained resin molded product in the in-plane direction was 8.2 W / (m · K), and the volume resistivity was 2.7 × 10 ⁴ Ω · cm. No flame retardancy was applicable in the UL94 V test. The thermal conductivity, volume resistivity and flame retardancy were measured by the same method as in Example 1.

(Example 3)
100 parts by weight of polypropylene (PP) as a thermoplastic resin and 100 parts by weight of expansive graphite as plate-like graphite are melted at 200 ° C. using a laboplast mill (manufactured by Toyo Seiki Co., Ltd., product number "R100"). A resin composition was obtained by kneading. The obtained resin composition was injection-molded at a temperature of 230 ° C. of the resin composition and a temperature of 40 ° C. of a mold to obtain a resin molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. As polypropylene, a product name "BC10HRF" manufactured by Japan Polypropylene Corporation was used. As the scaly graphite, a trade name "EXP-80S220" (expansion magnification 200 ml / g, volume average particle size: 180 μm) manufactured by Fuji Kokuen Industry Co., Ltd. was used.

The thermal conductivity of the obtained resin molded product in the in-plane direction was 7.8 W / (m · K), and the volume resistivity was 3.2 × 10 ⁴ Ω · cm. In the UL94 V test, the flame retardancy corresponded to V0. The thermal conductivity, volume resistivity and flame retardancy were measured by the same method as in Example 1.

(Comparative Example 1)
100 parts by weight of polypropylene (PP) as a thermoplastic resin and 50 parts by weight of oil furnace black as carbon black are melt-kneaded at 200 ° C. using a laboplast mill (manufactured by Toyo Seiki Co., Ltd., product number "R100"). To obtain a resin composition. The obtained resin composition was injection-molded at a temperature of 230 ° C. of the resin composition and a temperature of 40 ° C. of a mold to obtain a resin molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. As polypropylene, a product name "BC10HRF" manufactured by Japan Polypropylene Corporation was used. As the oil furnace black, a trade name "EC200L" manufactured by Lion Co., Ltd. (DBP oil absorption amount: 300 ml / 100 g, primary particle size: 41 nm) was used.

The thermal conductivity of the obtained resin molded body in the in-plane direction was 0.8 W / (m · K), and the volume resistivity was 2.5 × 10 ² Ω · cm. No flame retardancy was applicable in the UL94 V test. The thermal conductivity, volume resistivity and flame retardancy were measured by the same method as in Example 1.
(Comparative Example 2)
100 parts by weight of polypropylene (PP) as a thermoplastic resin and 20 parts by weight of scaly graphite as plate-like graphite are melted at 200 ° C. using a laboplast mill (manufactured by Toyo Seiki Co., Ltd., product number "R100"). A resin composition was obtained by kneading. The obtained resin composition was injection-molded at a temperature of 230 ° C. of the resin composition and a temperature of 40 ° C. of a mold to obtain a resin molded product having a length of 100 mm, a width of 100 mm and a thickness of 2 mm. As polypropylene, a product name "BC10HRF" manufactured by Japan Polypropylene Corporation was used. As the scaly graphite, a trade name "CPB-300" (average particle size: 300 μm) manufactured by Chuetsu Graphite Industry Co., Ltd. was used.

The resulting in-plane direction of the thermal conductivity of the resin molded body is 2.7W / (m · K), the volume resistivity was 2.5 × 10 ⁸ Ω · cm. No flame retardancy was applicable in the UL94 V test. The thermal conductivity, volume resistivity and flame retardancy were measured by the same method as in Example 1.

1,51,61,71,81,91,101,111 ... radiator 2,62 ... plate-shaped portion 2a ... first main surface 2b, 62b ... second main surface 2c ... one end 2d ... other end 2e, 5a ... Corners 3,63,93,103,113 ... Projections 3a ... Tip 4,64 ... Ground connection 5,65 ... Heat conduction sheet connection 6 ... Joint 6A ... Screws 10,50,70,80 ... Heat dissipation structure 20 ... Substrate 21 ... Joint hole 30 ... Heat source 40 ... Heat conduction sheet 52 ... Heat source connection portion 82 ... Frame-shaped side wall portion 83 ... Heat spreader

Claims (18)

A heat radiating body made of a resin molded body, which is used by being directly or indirectly thermally connected to a heat source that generates electromagnetic waves in the frequency band of 0.1 to 1000 MHz.
A plate-shaped part with a main surface and
A ground connection portion that is provided so as to protrude from the main surface of the plate-shaped portion and is connected to the ground, and a ground connection portion.
Equipped with
The thermal conductivity of the radiator in the in-plane direction is 3 W / (m · K) or more.
A radiator having a volume resistivity of 1.0 × 10 ⁻² Ω · cm or more and ^{less than 1.0 × 10 8} Ω · cm. A heat radiating body made of a resin molded body, which is used by being directly or indirectly thermally connected to a heat source that generates electromagnetic waves in the frequency band of 0.1 to 1000 MHz.
It has a plate-shaped part with a main surface,
The thermal conductivity of the radiator in the in-plane direction is 3 W / (m · K) or more.
The volume resistivity of the heat radiator, 1.0 × 10 ⁰ Ω · cm or more and less than 1.0 × 10 ⁶ Ω · cm, the heat radiating body. The radiator according to claim 1 or 2, wherein the plate-shaped portion has a thickness of 1.5 mm or more. The radiator according to any one of claims 1 to 3, wherein the shape of the corner portion of the plate-shaped portion is an R shape. The radiator according to any one of claims 1 to 4, wherein the plate-shaped portion has a disk-like shape. The radiator according to any one of claims 1 to 5, wherein the flame retardant level measured in accordance with the combustion standard UL94 is V1 or higher. The radiator according to any one of claims 1 to 6, further comprising a frame-shaped side wall portion provided on the main surface of the plate-shaped portion. The radiator according to any one of claims 1 to 7, which is a heat radiating chassis, a heat radiating housing, or a heat sink. The heat radiating body is a heat sink, has a first main surface and a second main surface facing the plate-shaped portion, and is provided with a ground connection portion on the first main surface side. The radiator according to any one of claims 1 to 8, wherein the plate-shaped portion and the ground connecting portion are integrally configured. The fin portion of the heat sink is configured by providing a plurality of protruding portions protruding from the plate-shaped portion on the second main surface side.
The radiator according to claim 9, wherein the shape of the tip of the protruding portion constituting the fin portion is an R shape. The heat radiating body according to claim 10, wherein the fin portions of the heat sink are formed by arranging the plurality of protruding portions in a dot shape. The radiator according to claim 10, wherein the fin portions of the heat sink are formed by arranging the plurality of protruding portions in a line shape and intermittently. The radiator according to any one of claims 10 to 12, wherein the fin portions of the heat sink are formed by arranging the plurality of protruding portions in a staggered manner. With the board
A heat source provided on the substrate and
The radiator according to any one of claims 1 to 13, which is arranged on the heat source and is directly or indirectly thermally connected to the heat source.
A heat dissipation structure. Further provided with a heat conductive sheet having a thermal conductivity of 1 W / (m · K) or more in the thickness direction.
The heat radiating structure according to claim 14, wherein the heat source and the heat radiating body are thermally connected via the heat conductive sheet. The heat dissipation structure according to claim 15, wherein the heat conductive sheet has a thickness of 0.5 mm or more. The heat-dissipating structure according to claim 15 or 16, further comprising a heat spreader different from the heat-conducting sheet, which is provided between the heat-dissipating body and the heat-conducting sheet. An electronic device comprising the heat dissipation structure according to any one of claims 14 to 17.

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