ELECTROTHERMAL SIMULATION AND EXPERIMENTAL DETECTION OF THE HOT-SPOT ONSET IN POWER BIPOLAR-TRANSISTORS

The hot spot onset in power bipolar transistors is examined, both from the experimental and simulation viewpoint. A simple three-dimensional electro-thermal model is proposed, including an accurate description of the layout structure, a fitting of the experimental dependence of i nput and output characteristics from the and packaging and heatsink th ermal Experimental detection of transient temperature maps, by means o f the infrared detection technique, validate the model results about t he hot spot onset and location for two commercial power BJTs. Collecto r current crowding is also described by the model in the hot spot mode . Finally, a detailed analysis of the hot spot onset locus in the I-c- V-ce plane is performed, showing a good agreement between experimental and simulation data. (C) 1997 Elsevier Science Ltd.