A semi-analytical method to predict printed circuit board package temperatures

A fast, easy-to-use method is developed to predict steady state temperatures on printed circuit boards subjected to heating by a single heat source or multiple heat sources. The method includes separate analytical solutions for the circuit board and for the chips to be mounted on the board. The board solution is developed using the Green's function method for solving the heat diffusion equation in the board. For the chip, the solution of the heat diffusion equation is obtained using the method of separation of variables. The temperature solution for the package is determined using an iterative procedure between the chip model and the board model. The method is verified by comparison with detailed finite element techniques. The agreement between the temperature distributions predicted by the two methods is very good.<
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