Green molding compounds for high temperature automotive applications

The high temperature reliability of automotive power devices, using Au wires, seems to be strongly dependent on the rate of degradation of the Au/Al wire bond interface. Although other types of wires are available (e.g. Al and Cu), Au wires appear to be preferred for the near future. Resistance measurements show that the choice of the proper molding compound is essential in achieving good high temperature results. Green molding compounds based on transition metal oxides as flame retardants have shown the best results. The goal of 20,000 hrs at 200°C and high current seems to be achievable through the combination of the use of the green molding compound (transition metal oxides) and the metallic barrier pad design.