Abstract
Gold-aluminum wire bonds in LSIs is drastically degraded by corrosion of Au-Al intermetallic compound. This corrosion is due to bromine gas that is emitted when an encapsulant resin is exposed to a high temperature. In this study, temperature dependence on this bond degradation was investigated. Degradation starting times of Au-Al compounds as a function of annealing temperatures ranging from 453 to 553 K were studied. Increase of annealing temperature minimizes the degradation time. Activation energy of this degradation behavior was calculated, 110 kJ/mol, which was similar to that of Au-Al intermetallic layer growth. Intermetallic compounds formed within gold-aluminum bond by high temperature annealing were corroded by bromine gas at room temperature. The corroded compound was found to be Au4Al.
