Optimizing Embedded Passive Content in Printed Circuit Boards

A genetic algorithm's optimization approach is used in conjunction with a size/cost model to study the optimum mix of passives (resistors and capacitors) to embed within a printed circuit board on an application-specific basis. Using the models and solution approach developed in this paper, the effect of board size on the optimum embedded passive solution (minimum cost solution) is studied, and an assessment of whether better system solutions can be found by varying or constraining the size of the board using several different criteria has been performed. Example optimization results for a GSM mobile phone are presented. The analysis has shown that the system size limitation when embedded passives are used is not only dependent on the quantity, type, and electrical properties (capacitance and resistance) of the embeddable components, but is also very sensitive to layout specifications and the placement of the nonembeddable parts.