Sub-notebook computer cooling technology via hybrid housings

Abstract

Until now, over 90% of notebook PC housings have been made of resin. Resin has inherently poor heat dissipation characteristics due to its low thermal conductivity. Although metal housings made of die-cast Mg and Al offer good heat dissipation, they are not widely used due to their low manufacturability and excessive weight. When weight and strength were the only items considered in housing design, the metal housing had a definite disadvantage. However, improvements in cooling by natural convection methods have now become equally important, as element electrical power consumption is increasing. We consider heat radiation from the housing as one of the most important methods for cooling PCs. Consequently, we have developed new housing technology for sub-notebook computers. The hybrid housing is composed of resin and metal to provide the unbeatable combination of structural strength, efficient heat dissipation, and light weight. This hybrid housing is manufactured by adapting an in-mold method where resin is fused to an Al board in order to shape the resin inside a metallic mold. We made several housings with various proportions of Al to resin to achieve a balance between weight and heat dissipation performance. We then simulated and examined the heat dissipation characteristics of each model. We found that the use of Al on the bottom and side of the hybrid housing provided the best balance between weight and cooling performance. This hybrid housing method results in a maximum temperature reduction of about 10/spl deg/C over conventional resin housings. This confirmed that the hybrid LCD housing is an effective means of cooling.