Definition: MCM classes

(MultiChip Module classes or MicroChip Module classes) Multichip modules are classified by substrate: MCM-C uses a ceramic substrate with wire bonding between the chips. MCM-D uses a dielectric layer over a ceramic, glass or metal substrate, and thin film interconnects are created on the dielectric layer. MCM-S uses a silicon substrate with tracks created in the silicon like regular ICs. Transistors can also be formed in the substrate. MCM-L uses a laminated circuit board with up to 25 tracking layers that evolved into the multichip package (see MCP). See MCM.

MCMs followed "hybrid microcircuits," which used a ceramic base, but MCMs have higher component and tracking densities. See hybrid microcircuit, system in package and chip package.