Aluminum extrusion involves forcing billets through a die. This is the best option for complex cross section aluminum heat sinks. Besides, die engineering incur significantly lower costs in comparison to castings. Extruded aluminum heat sinks also have fine finishes and generate stronger products. The only shortcoming of this option is the size constraints.

On the other hand, die cast heat sinks are made when molten aluminum is forced into a mold. After that, time is given to the billet to allow the molten aluminum to solidify. Unfortunately, the casting process is slower and produces end products with seams and imperfections.