Cu/Photosensitive-BCB Thin-Film Multilayer Technology for High-Performance Multichip Module

A new MCM-D technology which enables reliable fabrication of high-performance and low cost MCMs has been developed. The technology is based on Cu/Photosensitive-BCB thin-film multilayer structure. The fabrication process is reduced by using the newly developed Photosensitive-BCB, with a conventional photolythography process. The flexibility on design rules is allowed, because the Cu/BCB structure has the advantages of excellent planarization, and low electrical resistance of signal line. Long-term reliability test was successfully done; thermal cycle(-45/spl deg/C/125/spl deg/), high-temperature aging at 125/spl deg/C, and high-temperature/humidity(85/spl deg/C/85%). A prototype of high-density RISC module fabricated with the developed technology passed all the long-term reliability tests. The excellent electrical performance was also proved through the signal transmission tests with the prototype module.