An apparatus comprises a slider having a trailing edge and a leading edge. A laser diode unit comprises a submount and a laser diode mounted to the submount. The submount includes a mounting surface affixed to a first surface of the slider at the trailing edge such that a first surface of the submount faces toward the leading edge of the slider. A thermally conductive material covers the first surface of the submount and at least a portion of the first surface of the slider. The thermally conductive material serves as a thermal conduction pathway between the submount and the slider.