Effect of Bromine in Molding Compounds on Gold - Aluminum Bonds

Degradation rates of gold wire ball bonds on aluminum bonding pads were studied in two molding compounds as a function of bromine concentration, temperature, and time at temperature. The measure of degradation was the resistance increase of the aluminum-gold contact. The rate of degradation was observed to increase with increasing bromine content and temperature for both molding compounds. However, the bromine content dependence of the activation free energy of the degradation reaction indicates a different degradation mechanism for each molding compound.