Filial Finish: Printed Circuit Boards

摘要

For years the preferred finishes for circuit boards were either hot air solder leveling (HASL) or I electrolytic nickel/gold. With the rapid increase in technological improvements, it became necessary to develop more sophisticated technologies. The main driver was to produce finer-sized lines and pads with better planarity. As the boards continue to shrink in size, the surface geography becomes more valuable. The need for this real estate to be smoother required better distribution than possible with electrolytic processes. The need to eliminate bussing also drove the industry to utilize the newer electroless processes being developed. There is also the perceived environmental benefit to eliminate the lead in the HASL process.