Low, Medium And High Circuit Density Multichip Modules

Multichip modules (MCMS) employ uncased chips mounted and interconnected on multilayer circuit boards. The interconnect is fabricated using alternate layers of conductor and dielectric thin films connected by vias through the interlayer dielectric. Depending upon the performance, assembly flexibility and cost considerations, various approches can be used for fabricating and packaging MCMs. A number of circuit board technologies and packaging schemes applicable to different MCM applications are summarized in this paper. An effort is made to classify these MCMs into low, moderabe or high circuit density types. Several examples are provided to point out the suitability of various MCM approaches to the selected applications.