Ultra low loop conversion from gold to copper wire

It has been a trend to convert gold wire to copper wire in manufacturing of semiconductor chip due to cost effectiveness. Another motivation for the conversion comes from the physical properties of copper wire. Copper wire offers the advantages of presenting higher mechanical strength, lower electrical resistance and slower intermetallic growth. Aside from the differences in term of chemical stability, copper is a stiffer material as compared to gold. It has been determined that copper wire requires new process optimization in comparison to gold wire. Parameter adjustments for ball bond formation, stitch bond formation, and looping profile are needed during conversion from gold to copper.