The application of diamond wafers in spacecraft thermal transfer technology

With the growth of components and overall energy consumption in spacecraft, existing thermal management technologies urgently need to enhance or introduce efficient heat conduction solutions.Diamond heat sink provides a new possibility to solve this problem, which can replace copper and aluminum based heat transfer products to meet the high heat flux heat dissipation requirements of highly integrated components within payloads.

Aluminum and copper are traditional high-performance thermal conductive materials. Due to their mature technology, low cost, and good processability, they have been widely used as thermal conductive materials in aerospace, aviation, and civil industries. With the development of material preparation technology, ultra-high performance thermal conductive materials represented by carbon fiber materials, diamond heat sinks, etc. have been rapidly developed and preliminarily applied. These materials have the characteristics of low thermal expansion rate (CET), ultra-high thermal conductivity coefficient, and low density, making them the preferred alternative materials for aluminum and copper materials.

1. Diamond heat sink

CSMH, as one of the earliest representative enterprises in China to study diamond and achieve mass production, currently has the ability to prepare 2-4-inch diamond wafers with a thermal conductivity of 1000-2000W/(m.K), a thickness of 0.2-1mm, and can provide metalization, graphitization, and drilling. It is applied in aircraft thermal management to achieve efficient heat dissipation.

2. Diamond composite materials

The composite material composed of diamond powder and metal materials is also one of the development trends of ultra-high performance thermal conductive materials, which is also a research focus of chemical deposition and has made breakthrough progress. The density and thermal conductivity of this type of material can be adjusted, making it suitable for mechanical processing and welding. The thermal conductivity of diamond silver composite material is 400~600W/(m · K), and the density is 5.8 × 103 (kg/m3); Diamond copper composite material thermal conductivity: 600-1200W/m · K, density: 5.9 × 103kg/m3; Diamond aluminum composite material thermal conductivity: 550-600W/(m · K), density: 3.1 × 103kg/m3.

CSMH uses the MPCVD method to prepare large-sized and high-quality diamonds, and currently has mature products such as diamond heat sinks, diamond wafers, diamond windows, diamond heterojunction integrated composite substrates, etc. Among them, the thermal conductivity of diamond heat sinks is 1000-2200W/(m.k), and the surface roughness of diamond wafer Ra<1nm. It has been applied in aerospace, high-power semiconductor lasers, optical communication, chip heat dissipation, nuclear fusion and other fields.