Multichip module substrates

The three major technologies used to fabricate substrates for multichip mod ules (MCMs) are described. These are MCM-L, composed of metal traces on sta cked organic laminate sheets; MCM-C, metal patterned and interconnected on co-fired ceramic layers; and MCM-D, vapor-deposited, patterned metal layers alternating sequentially with spun-on or vapor-deposited dielectric thin f ilms. Examples of circuits fabricated at APL using each of these MCM techno logies are presented.