Criticality of die placement on wire bonding

It is pointed out that wire bonder suppliers are keeping up with the demands for six-sigma quality levels by opening up process windows and minimizing sensitivity of the equipment to set up and material variations. Die bonder suppliers are challenged even more. Their process windows are in fact becoming tighter. Fine-pitch, large I/O packages have put greater constraints on die positioning within these packages. The author reviews the issues driving this constraint and discusses ways in which packaging designers can relax placement accuracy requirements and how assembly process engineers can accommodate die placement error in these packages. It is noted that not only are there die placement-tolerant designs available, but also wire bonding processes which can accommodate or compensate for nominal 3-sigma placement error in current generation die bonding equipment without device or package design changes