system in package

A system in package (SiP) or system-in-a-package is a number of integrated circuits enclosed in a single module (package). The SiP performs all or most of the functions of an electronic system, and is typically used inside a mobile phone, digital music player, etc.  Dies containing integrated circuits may be stacked vertically on a substrate. They are internally connected by fine  wires that are bonded to the package. Alternatively, with a flip chip technology, solder bumps are used to join stacked chips together.