Patent ID: 7710721

Claim:
A power inverter for supplying an ac power to a rotary motor mounted on a vehicle, comprising: a metallic housing, a coolant passage forming body arranged in the metallic housing and including a coolant passage and an opening communicating with the coolant passage, a power module including a plurality of power switching elements, a heat radiating fin, a metallic base having a surface on which the power switching elements are held and another surface on which the heat radiating fin is arranged, a direct current terminal and an alternating current terminal so that an electric power of direct current supplied from the direct current terminal is converted to an electric power of alternating current by switching operation of the power switching elements to be output from the alternating current terminal, and arranged in such a manner that the heat radiating fin extends into the coolant passage through the opening of the coolant passage forming body and the opening is closed by the metallic base, and a capacitor module held on the metallic housing and including a capacitor cell, a case containing the capacitor cell, and an electrically conductive connecting plate connected to the capacitor cell in the case and projecting from the case, and a switching drive circuit substrate for driving the power switching elements, wherein the capacitor module faces to the power module to form a space therebetween, and the switching drive circuit substrate is arranged in the space.