A kind of diamond/copper gradient composite material and its preparation method

Abstract

The invention relates to a diamond / copper gradient composite material and a preparation method thereof. The preparation method comprises the following steps: respectively mixing coarse grain diamond and fine grain diamond with an adhesion agent at first; sequentially flatly laying fine grain diamond-coarse grain diamond-fine grain diamond by a certain thickness in a metal mold, pressing by using a cold pressing technology, demolding, and drying to obtain a gradient diamond preformed unit; and then permeating fused copper or copper alloy in the preformed unit, cooling and demolding and then obtain the diamond / copper gradient composite material. High heat conduction performance of the composite material prepared by coarse grain diamond can be kept, thermal resistance caused by the reason that the roughness of the surface, which is in contact with a chip, of a product is over high can also be reduced, excellent performance of the material is played fully, the technological process is simple, and the prepared diamond / copper gradient composite material can be widely used for electronic packaging devices such as semiconductor lasers and microwave power electronics.

Description

technical field [0001] The invention belongs to the technical field of thermal management materials, in particular to a diamond / copper gradient composite material and a preparation method thereof. Background technique [0002] Diamond / copper composite materials have become important candidate materials for heat dissipation of electronic packaging devices such as semiconductor lasers and microwave power electronics due to their excellent comprehensive properties such as high thermal conductivity, low expansion and adjustable physical properties. Patent ZL200710178844.5 introduced high thermal conductivity diamond / copper composite material and its preparation method. In the research of diamond / copper composite material, it was found that with the increase of diamond particle size, the thermal conductivity of the composite material increased, but the composite The surface roughness of material products is relatively high, and after the size of diamond particles is reduced, alth...

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Problems solved by technology

Patent ZL200710178844.5 introduced high thermal conductivity diamond / copper composite material and its preparation method. In the research of diamond / copper composite material, it was found that with the increase of diamond particle size, the thermal conductivity of the composite material increased, but the composite The surface roughness of material products is relatively high, and after the diamond particle size is reduced, although the surface roughness is significantly reduced, the thermal conductivity is also reduced

In the heat sink application process of diamond / copper composite materials, it is required to ensure the high thermal conductivity of the heat sink, and at the same time, it is hoped that the surface quality of the heat sink should be below Ra 0.5 μm. If the composite material is made of 150 μm diamond, the thermal conductivity can reach 550W. / mK or more, but the surface Ra of the product can only reach 1μm. When connecting with the chip, the roughness is too high to affect the performance of the material.

In order to improve and reduce the surface roughness, some people plated (such as nickel, copper, etc.) or sprayed (such as copper) a metal layer on the surface of the diamond / copper composite material, and then polished the metal layer. Through this process, the diamond / copper composite material The surface roughness is greatly reduced, but the process is complicated, it is difficult to guarantee the dimensional accuracy of the device, and the interface bonding force of different metal layers is different, and the problems of bubbles and bulges are prone to appear in the subsequent application process

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