Low cost, high performance, high volume heatsinks

Higher-powered electronics are being integrated into automobiles rapidly. With these electronics comes the problem of how to cool this equipment economically. Heat sink costs have not benefited nor adapted to the high volume nature of automotive electronics. Specially shaped heat sinks are much more efficient for a given size than the aluminum extrusion-based ones most prevalently used in automobiles. However, machining costs preclude specially shaped heat sink use in most automotive applications. High purity extruded aluminum has always been a good heat sink material for electronic components. Casting aluminum to create more efficient and useful shapes has a severe penalty in thermal conductivity due to the impurities necessary for casting. Porosity is another significant factor which lowers thermal conductivity in both die and hand cast aluminum. This paper gives show a new heat sink design and material process that allows porosity-free low cost heat sinks to be diecast into complicated 3D shapes. A cost and performance analysis comparing different high volume heat sink manufacturing methods, die cost, and per piece cost are examined for various commercial copper-based, zinc, zinc-aluminum, and aluminum die casting materials. Additionally, the paper shows where the automotive industry can benefit from these technologies and where they may not be as appropriate.