A thermal design methodology for multifinger bipolar transistor structures

A technique is presented that allows the increase in maximum temperature rise due to thermal coupling in multifinger structures to be predicted for a wide range of finger lengths and spacings by reference to a single, normalized characteristic. Application of this approach to the design of thermal resistance in multifinger structures results in a fast and straightforward method for generating families of structures that meet given power and temperature criteria without thermal simulation-based optimization. The usefulness of this approach is illustrated through solution of a practical design problem, and the accuracy of the method is verified by comparison with the final solutions to numerical simulation.