Test data on leadless chip carriers with ceramic substrates in severe random vibration environments

Relatively new in electronic packages are the hermetic chip carriers (HCC). LSI technology, coupled with the HCC packaging concept, offers density which is two to five times more dense than conventional dual-in-line or flatpack concepts. The present study is concerned with a research program which has been conducted in connection with the application of leadless hermetic chip carriers to a high reliability system design. Because of the thermal coefficient of expansion differential between the HCC and its substrate, the specific choice would be ceramic or porcelain steel technologies. The HCC can assemble to either a multilayer thick film or cofired ceramic substrate. An on-board computer with a 128K x 22 memory capacity is currently being developed. Two approaches are being considered. The first uses eight 16K trays, while the second employs four 32K trays. In vibration development tests, both the 16 and 32K trays were vibrated in the same fixture.