A heat sink assembly for a power module is provided. The assembly includes a main body having a first cooling circuit and a second cooling circuit. The first cooling circuit includes a first plurality of channels, at least one first end channel, at least one second end channel, a first inlet, and a first outlet. The first cooling circuit is adapted to provide a first flow of a coolant through the main body. The second cooling circuit includes a second plurality of passages, at least one first end passage, at least one second end passage, a second inlet, and a second outlet. The second cooling circuit is adapted to provide a second flow of the coolant through the main body. The first cooling circuit and second cooling circuit is adapted to provide a cross flow of the first flow and second flow through the main body respectively.