Area array interconnection with Cu-PI thin films on a multi-layer glass-ceramic substrate

The microelectronic packaging technology for the SS-1 supercomputer utilizes an interposer to interconnect integrated circuit devices. Area array solder bump interconnection has been used successfully in attaching both chips to the interposer, a Cu-PI thin film/multi-layer glass-ceramic substrate, and attaching this interposer to a larger Cu-PI thin film/glass-ceramic substrate. This highly reliable chip interconnection technology has been extended to interposer to substrate interconnection, with commensurate increases in both the interconnection density and total number of I/O connections per module. In this paper, key elements of both the flip-chip and interposer join and replace processes are reviewed. Additionally, optimization of the thin film metallurgy and join/replace parameters necessary to achieve high reliability are presented