Finite layer spectral method for thermal analyses of layered printed circuit boards

A finite layer spectral method (FLSM) which is designed for three-dimensional thermal analyses of layered printed circuit boards (PCBs) with surface mounted components is presented. The method can be extended to solve problems with internal heat sources. Using this method, designers descretize PCBs in one direction and basic thermal analysis theories are introduced to establish the relations between two adjacent layers. Systematic analytical methods have been developed to overcome so-called dimension catastrophe. The formulae for FLSM are very simple and general. It is easy to implement the corresponding computer code for general purposes. Numerical comparisons of FLSM results with those obtained from finite difference methods, analytical solutions, and available experimental results are very encouraging. The examples calculated in terms of FLSM show that this method gives very accurate and reliable results