Parametric FEA thermal model for QFP packages

Computer models are used with increasing frequency in the industry to predict package thermal performance. To reduce calculation times to acceptable levels, simplifications are often made in one or more of the following three areas: 1) package geometry, 2) printed circuit board (PCB) or 3) heat transfer to the ambient. This paper provides guidelines for implementing simplifications in each of these three areas in the area of a single QFP package attached to a board and evaluates their accuracy by comparing the results of the simplified models either with appropriate FEA computer models or experimental measurements