A novel electroplating technology with leveling, minimum surface deposition for HDI application

Electrolytic copper micro via filling is an enabling technology, prominently used in today's manufacture of high density interconnect (HDI), to be driven by the needs for faster speed, smaller dimension and higher performance versus communication and electronic devices; and also in response to the evolution of the wafer manufacturing technology, which eventually required smaller and smaller pitch BGA substrate for packaging, more dense I/O counts increase transmission efficiency, and minimize routing reduce signals disturbance. Thus, the trend of circuits on HDI boards will tend to be constructed by high density stacked vias and smaller vias. And the increasingly difficult micro via geometries must be filled without void and skip plating over million vias, while maintaining plating rates capable of delivering production throughputs. This paper describes the study on the factors affecting copper electroplating for micro via filling, and developing new plating formula with great surface leveling, thinner copper deposit thickness for direct current (DC) copper process for HDI application.