A semiconductor module, including a semiconductor device mounted on a printed circuit board (PCB), the PCB having an electrical connection to the semiconductor module, and a heat sink in direct contact with the semiconductor device, the heat sink being formed with a first end and a second end, the first end and the second end being formed with different heights, wherein the semiconductor module allows air flow to pass through the semiconductor module, radiating heat away from the heat sink. Another semiconductor module, including a semiconductor device mounted on a PCB, a heat sink in direct contact with the semiconductor device, the heat sink having a first portion and a second portion, wherein the first portion has a flat shape and is in direct contact with the semiconductor device and the second portion has a corrugated shape and is not in contact with the semiconductor device, wherein the semiconductor module allows air flow to pass through the semiconductor module, radiating heat away from the heat sink.