US Patent 7091587 Semiconductor device

An electrode on a main surface of a module board, to which an emitter electrode of a semiconductor chip which includes a switching element of a power supply control circuit that supplies a power supply voltage to amplifier circuit parts of a power module of a digital cellular phone, is electrically connected to a wiring in an internal layer of the module board through a plurality of via holes. Further, the wiring is electrically connected to an electrode for the supply of the power supply voltage, which is provided on a back surface of the module board. Accordingly, an output characteristic of the semiconductor device is improved.