An immersion cooling apparatus includes a multi-terminal thermally conductive module that supports and encloses a power semiconductor device and a housing defining a flow-through chamber in which the thermally conductive module is mounted and through which liquid coolant is circulated. The thermally conductive module has first and second oppositely disposed connector headers housing terminal pins or blades electrically coupled to the semiconductor device, and the connector headers protrude through openings in oppositely disposed sidewalls of the housing so that the portion of the thermally conductive module between the connector headers is suspended in the chamber and immersed in the circulating coolant. The thermally conductive module is sealed against the housing sidewalls around the openings, and one of the sidewalls is removable to facilitate installation of the thermally conductive module in the housing or its subsequent removal.