Effect of Gamma Radiation and Thermal Cycle on Hardness Properties of Au Ball Bond

Abstract

Effect of gamma radiation and thermal cycle test of Au ball bond on hardness properties has been investigated. The Au ball bond was subjected to gamma radiation with 5 Gy. Afterwards, thermal cycle test was performed using temperature cycle of (-65) °C to 150 °C for 10, 100, and 1000 cycles. Nanoindentation test was carried out to obtain the hardness properties of Au ball bond. Irradiated package shows an increasing in their hardness. The hardness of the ball bond keeps increased after exposure to thermal cycles up to 1000 cycles for as-received sample. However, for irradiated Au ball bond, the value of hardness increased as the cycle increased up to 100 cycles and decreased as the cycles number increased to 1000. The decrease in the hardness value due to the coarsening behavior of the grain size of the Au and recystallization process. These nanoindentation results are important in assessing the strength of Au ball bond after exposure to synergic effect of both radiation and thermal cycles.