To obtain an electrically stable ground by preventing a displacement current from flowing to the ground by providing a conductive layer having a potential which is different from the ground potential in an insulating substrate or on the surface of the substrate on which no semiconductor element is mounted.
Since an emitter circuit 502 contained in a package is electrically connected to an inner-layer emitter circuit 510 and an insulating substrate 505 is interposed between the circuit 510 and a ground surface 506 connected to a ground 509, the circuit 510 is connected to a ground 607 through an inner emitter-to-ground capacitance 603. In addition, since the emitter circuit 510 has the insulating substrate 505 between a collector circuit 503 contained in the package and the ground surface 506, the circuit has a collector-to-inner layer emitter capacity 602 between the circuits 503 and 510. Therefore, such an inverter device that has no possibility of malfunctioning a controller having another electronic circuit commonly using the ground 509 can be obtained, because no displacement current flows.
SAITO RYUICHI
KUSHIMA TADAO
KOIKE YOSHIHIKO
SHIMIZU HIDEO
