Influence of the Low Pressure Cold Spray Operation Parameters on Coating Properties in Metallization of Ceramic Substrates Using Copper and Aluminum Composite Powder

The low-pressure cold spray (LPCS) technique could be an attractive method for copper metallization of ceramic substrates for power module applications due to its one-step quick and low-temperature process. However, LPCS manufacturing pure copper coating on ceramics is still challenging due to its low deposition efficiency and poor adhesion strength. Our previous study has succeeded in producing a ZrO₂ metallization with high deposition efficiency by using a feedstock powder mixture of copper-aluminum. The copper content in the coating, however, was not high enough for power module applications. Therefore, in this study, we aim to improve the purity in copper content of copper and aluminum composite coatings deposited on Al₂O₃ and ZrO₂ substrates. Thus, the effect of the LPCS parameters on copper content and thickness were evaluated at the composited coating layer. The coating microstructure was evaluated by scanning electron microscope observation with back-scattered electron detection. Meanwhile, adhesion strength and hardness were measured. Preliminary results show that decreasing with the standoff distance and increasing the gas pressure, we successfully obtained higher thickness and copper content coating.