Abstract
Theoretical study is carried out to investigate the effects of boundary conditions on the evaluation of the effective thermal conductivity of composite boards. The board is a simplified model of an electronic wiring board and consists of two elements, a via and a dielectric, having high and low thermal conductivities. Two types of boundary conditions, namely the heating/cooling at uniform temperatures (Case 1) and the heating/cooling through reference rods (Case 2) are applied, and the effective thermal conductivity of the board is evaluated. From the numerical results, it is found that the heat flow inside the reference rods is not uniform near the board, and consequently the effective thermal conductivity of Case 2 is smaller than that of Case 1.
