Multi-chip module

A multi-chip module (MCM) is generically an electronic assembly (such as a package with a number of conductor terminals or "pins") where multiple integrated circuits (ICs or "chips"), semiconductor dies and/or other discrete components are integrated, usually onto a unifying substrate, so that in use it can be treated as if it were a larger IC. Other terms for MCM packaging include "heterogeneous integration" or "hybrid integrated circuit". The advantage of using MCM packaging is it allows a manufacturer to use multiple components for modularity and/or to improve yields over a conventional monolithic IC approach. Multi-chip modules come in a variety of forms depending on the complexity and development philosophies of their designers. These can range from using pre-packaged ICs on a small printed circuit board (PCB) meant to mimic the package footprint of an existing chip package to fully custom chip packages integrating many chip dies on a high density interconnection (HDI) substrate. The final assembled MCM substrate may be done in one of the following ways: The substrate is a multi-layer laminated printed circuit board (PCB), such as those used in AMD's Zen 2 processors. The substrate is built on ceramic, such as low temperature co-fired ceramic The ICs are deposited on the base substrate using Thin Film technology. The ICs that make up the MCM package may be: ICs that can perform most, if not all of the functions of a component of a computer, such as the CPU. Examples of this include implementations of IBM's POWER5 and Intel's Core 2 Quad. Multiple copies of the same IC are used to build the final product. In the case of POWER5, multiple POWER5 processors and their associated off-die L3 cache are used to build the final package. With the Core 2 Quad, effectively two Core 2 Duo dies were packaged together. ICs that perform only some of the functions, or "Intellectual Property Blocks" ("IP Blocks"), of a component in a computer. These are known as chiplets. An example of this are the processing ICs and I/O IC of AMD's Zen 2-based processors.