The AEC-Q104 standard gives a clear definition of the multi-chip module (MCM) and specifies how complex multi-chip packages - including system-in-package (SiP), chip-on-board (COB), system-on-chip (SoC) and stacked packages - are qualified for automotive use. The standard also defines dedicated verification tests, BLR and DROP, for the reliability of the connections within an MCM system.