Effects of diamond content and heat treatment on the thermal properties of copper matrix composite materials prepared by cold spraying

The demand for thermal conductivity in electronic packaging materials is increasing. Diamond-reinforced copper matrix composites have been the subject of considerable interest as a material with the potential to exhibit high thermal performance, in comparison to many other materials. This paper investigates the effects of diamond content and heat treatment on diamond-reinforced copper matrix composites. Following the application of a heat treatment at 400°C, the copper matrix underwent recrystallisation, and the grains are fine and uniform. Consequently, the material exhibited enhanced thermal conductivity while maintaining a low coefficient of thermal expansion (CTE). When the heat treatment temperatures were higher, the thermal conductivity was found to be lower, while the CTE was higher. Consequently, a heat treatment temperature of 400°C was deemed appropriate. The thermal conductivity decreases gradually with the increase of copper-plated diamond addition. It was noted that the thermal performance of the material was superior when the addition amount of copper-plated diamond was 20%.