Overlay high-density interconnect: a chips-first multichip moduletechnology

A high-density interconnection (HDI) technology that involves placing bare chips into cavities on a base substrate and fabricating the thin-film interconnect structure on top of the components is described. The interconnects to the chip I/O pads are formed as part of the thin-film fabrication process, thus eliminating the need for wire bonds, tape-automated bonds (TABs), or solder bumps. The need for advanced packaging and interconnection and the standard chips-last multichip module (MCM) technologies are reviewed. The HDI chips-first MCM technology's IC pretest requirements and approaches, substrate and packaged parts test, and substrate packaging are discussed