ON THE EFFECT OF NONLINEAR BOUNDARY-CONDITIONS FOR HEAT-CONDUCTION INDIAMOND HEAT SPREADERS WITH TEMPERATURE-DEPENDENT THERMAL-CONDUCTIVITY

For steady-state heat conduction in diamond heat spreaders with temper ature-dependent thermal conductivity, we examine the valid range of th e commonly used approximate solution against a rigorous solution which we have recently formulated, The basic difference between our work an d the approximate solution lies in the boundary condition (bc) of the transformed temperature over the spreader-sink interface-we use a nonl inear be whereas the be in the approximate solution has been assumed t o be linear, We point out that the valid range of the approximate solu tion is determined by the temperature difference above the ambient ove r the interface, The discrepancy between the two solutions becomes sev ere (>10%) for devices of radius around 50 mu m involving high power d issipation (>20 W).