The most common failure mode of wirebonds is delamination/cracking at the wire/bond-pad and bond-pad/chip (or substrate) interfaces.  A 1-mil Au wire wedge-bonded to an Au bond pad on 96% Al2O3 substrate is examined and modeled using non-linear finite element analysis (FEA).  The model was optimized to reduce stress/strain and a plastic strain distribution for the optimized structure was generated.