Effect of contraction heat flow on thermal resistance around contact surface

Contact thermal resistance is one of the critical issue for cooling of electronics. Nowadays, to reduce contact thermal resistance, many kinds of high thermal conductive grease have been developed. Further, for high power electronics area, to omit contact thermal resistance extremely, no contact surface device, which means package and heat sink are made by continuous one material, is employed. However, this structure is not flexible and can be employed in limited conditions. Under such circumstance, though contact thermal resistance is a big issue, details of heat flow phenomena around the contact surface between two materials is still unclear. Therefore, in this study, we conduct thermal network analysis about heat flow around contact surface, and discuss details of contraction effect and spreading effect of heat flow.