Research on fabrication technology of copper and single crystal silicon carbide composites

With the continuous expansion of the application of high-power semiconductor lasers, the continuous enhancement of laser output power and electro-optical conversion efficiency has emerged the primary technical development direction. The semiconductor laser with higher power output requires more current injection and better heat dissipation performance. Therefore, the market demand for heat sinks which possess higher thermal conductivity and capability of carrying large current injection is growing rapidly. In this paper, a high-power semiconductor laser heat sink with stress-matched is fabricated. Its substrate is single-crystal silicon carbide with high thermal conductivity. Its conductive layer is a thick Copper(Cu) layer deposited by low-temperature liquid phase metal electroplating technology. In this paper, the effects of different current density and thickness on the surface morphology, surface roughness and stress of copper-plated materials are studied. The experimental results demonstrates that when the current density is 3A/dm², the surface particles are the smallest and the surface roughness is the lowest as 4.84nm, and the surface roughness of the metal layer decreases with the increase of the thickness of the plating. When the thickness of the copper plating layer is 44um, the minimum stress between Cu and SiC is 24MPa. The data show that 3A/dm² is a suitable deposition current density. The thickness of the deposited plating is the main factor affecting the stress, and the current density is the secondary factor.