Advanced thin copper electroplating process for HDI microvia filling application

Electrolytic copper microvia filling is an enabling technology, prominently used in today´s manufacture of high density interconnect (HDI) and packaging substrate applications for better reliability, increased circuit densification, design flexibility and thermal management. To meet these needs, seemingly incompatible objectives must be met. Thinner and more uniform surface copper deposits have to be produced; increasingly difficult microvia geometries must be filled, while maintaining plating rates capable of delivering production throughputs. This paper describes a new panel and pattern-plate, direct current (DC) copper electroplating process designed for packaging substrate and HDI applications. Microvia filling performance, surface distribution and product reliability as a function of a variety of physical processing variables is discussed.