Estimation of aluminum and gold bond wire fusing current and fusing time

Wirebonding is the common method for electrically connecting the semiconductor device to the external leads or pins. Permanent damage to wirebonds would occur if the wires could not dissipate the energy, due to excessive current, delivered through the wires. This current overstress damage is recognized as fused bond wires. In this paper, the simplified model developed by Loh (1983) has been used to predict the fusing time and the fusing current of aluminum and gold wires as functions of wire length and wire diameter. In addition, the equation obtained by Loh has been put into more convenient form by eliminating the dependence on the bond wire diameter. Results from both approaches have been presented in graphical form so that package design engineers would be able to estimate the fusing current for a given fusing time. Conversely, the fusing time for a given current passing through the wires could be easily obtained from the design graphs