Mounting arrangements for high voltage/high power semiconductors

Abstract

A mounting arrangement for a pair of relatively high voltage, press-pack semiconductors positioned in spaced apart relationship on a support surface of a heat sink comprises an enclosure formed of electrically insulative material having a mounting surface mating with the heat sink support surface. The arrangement has a pair of spaced openings extending through the mounting surface, each of which is configured for relatively accurately positioning a respective one of the semiconductors. A groove circumscribes each opening with a third groove spaced from and circumscribing the pair of grooves on the mounting surface. An O-ring in each groove defines an area between the grooves isolated from environmental contaminants when the enclosure is clamped to the heat sink. An electrically conductive mounting plate is positioned in each opening and electrically insulated from the heat sink but electrically connected to a respective semiconductor. A relatively stiff spring bar extends between the semiconductors with opposite ends of the bar supported upon a respective one of the semiconductors. The heat sink and the bar are coupled tensioning the bar toward the heat sink compressing the semiconductors between ends of the bar and the heat sink. The tensioning device comprises a bolt extending through an aperture in the heat sink, the enclosure mounting surface, and the bar between the semiconductors. Another groove circumscribes the aperture in the enclosure mounting surface and an O-ring positioned therein environmentally isolating the aperture from the area between the grooves when the enclosure is affixed to the heat sink.