Mechanical characterization of the heat affected zone of gold wirebonds using nanoindentation

Abstract

The present work studies the mechanical properties of mechanically polished gold wire and wirebond using nanoindentation. Metallography of wirebond reveals undesirable coarse grain structure in HAZ due to recrystallization and grain growth. For our gold wire, the recrystallization temperature found using D.S.C. was 340.66°C and the dopants were identified using TOF-SIMS and hardness dependence on load was studied using nanoindentation. The nanoindentation of wirebond has confirmed a v -shaped hardness profile with minima at 166 μm along the HAZ. The elastic modulus varied independent of the microstructure. A yield stress profile based on empirical hardness-yield strength correlation is predicted for the wirebond.