Nearly ten years ago the National Security Agency's Laboratory for Physical Sciences (LPS) in College Park, Maryland, began investigating the use of industrial diamond for thermal management of electronic assemblies. To achieve ultra-high computing speeds through the reduction of signal path lengths, they would have had to condense a 20 kW computer into a 15 cm/side cube, creating a 6 W/cm³ thermal density. The excellent electrical, mechanical, and thermal properties of diamond made it an obvious choice for conducting the large amount of heat out of this cube, so the LPS incubated the growth of the chemical vapor deposited (CVD) diamond industry in this country. The LPS subsequently published several papers on the performance of CVD diamond as a component of electronic packaging. What they have not studied is the use of CVD diamond in space applications, where charged particles are in abundance. This report is intended to provide insight into the electrical, mechanical, and thermal properties of CVD diamond which make it so attractive for use in electronic packaging and into the questions which remain about its suitability for space flight applications. 

Diamond is mechanically one of the strongest materials known and has very high dielectric strength. Its coefficient of thermal expansion (CTE) is on the order of silicon's, and its thermal conductivity is unmatched. These properties are all related to the strength of the carbon bonds in the crystal and its structure. For illustrative purposes, Table 1 shows room temperature values for the properties of materials often used in electronic packaging