Heat dissipation sheet having high load carrying capacity and high thermal conductivity

Abstract

The invention provides a heat dissipation sheet which achieves a good balance between high load carrying capacity and high thermal conductivity at a low cost. A heat dissipation sheet which has a configuration wherein silicone composition layers containing a thermally conductive filler are laminated on both surfaces of a reinforcing layer. The heat dissipation sheet is configured such that: the ten-point average roughness (RzJIS) of a surface of at least one of the silicone composition layers on the both surfaces of the reinforcing layer, the surface being not bonded to the reinforcing layer,is within the range of from 15 [mu]m to 70 [mu]m (inclusive); the durometer A hardness of the silicone composition layers is within the range of from 25 to 90 (inclusive); and the thermal conductivityof the heat dissipation sheet in the thickness direction is 2.5 W / (m.K) or more.

Description

technical field [0001] The present invention relates to a heat sink that is closely bonded to the interface between an electronic component and a heat sink or a heat dissipation portion such as a circuit board to cool the electronic component that generates heat. Background technique [0002] Heat sinks are usually formed by coating a silicone composition containing a thermally conductive filler (hereinafter referred to as a silicone composition) on both sides of a reinforcing layer such as glass cloth. Due to its high thermal conductivity, electrical insulation, and operational Therefore, in the field of electronic materials, it is used in close contact with the interface between electronic components and heat dissipation parts such as heat sinks or circuit boards to cool electronic components that generate heat. For example, Patent Documents 1 to 5 below disclose heat sinks in which a heat conduction layer is provided on a reinforcing layer. [0003] However, with recent ...

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Problems solved by technology

[0004] However, the high thermal conductivity of heat sinks based on the prior art requires the use of a large amount of expensive thermally conductive filler materials and the use of expensive metal foils for reinforcement layers, which increases the cost and is not ideal.

On the other hand, in terms of enhancing the adhesion with electronic components and heat dissipation parts based on the prior art, by increasing the load between the electronic components and heat dissipation parts, the interface thermal resistance can be reduced and the heat dissipation can be improved. However, the conventional heat dissipation There is a problem in the sheet that if excessive load is applied, cracking will occur

If such a crack of the heat sink occurs, it will lead to poor insulation or heat accumulation, resulting in malfunction of electronic components, which may cause serious accidents

[0005] In addition, the enhancement of the load resistance of the conventional heat sink can be improved by thickening the glass cloth of the reinforcement layer and increasing the fiber diameter of the glass cloth. Reduced heat dissipation, so still not ideal

[0006] In addition, attempts were made to improve heat dissipation by reducing the thickness of the heat sink, but the load resistance was inevitably impaired, so the above-mentioned problems could not be solved.

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