Thermal Design of a Slim Notebook Personal Computer

This paper describes the outline of thermal design technology used for MITSUBISHI ultra-slim notebook Personal Computer "Pedion". As of September 1997, "Pedion" is the world's thinnest at 18 mm thick among A4-size notebook computers. We have developed innovative thermal solutions for ultra-slim Notebook Pc where only natural convection cooling can be used for heat rejection. The first solution is cooling system for CPU by using the bottom chassis (Mg die-cast) as a heat spreader combining with A1 heat transfer plate. And the size and the thickness of A1 plates were optimized by thermal analysis using Finite Volume Method. As the second solution, a new coating which can reduce touching warmth of Mg die-cast enclosure have developed and already been reached the stage of practical use.