Influence of the soldering process quality on thermal resistance of RF transistors

The paper presents the results of experimental studies illustrating the influence of the assembly quality of RF transistors on their thermal resistance. One of the measure of assembly quality is the total voids in the solder joint. The influence of the location of the tested transistors on the printed circuit board on the value of thermal resistance was considered. The non-uniformity of temperature distribution on the surface of the tested transistors was also analyzed. The impact of the obtained research results on the lifetime of the considered transistors was discussed.