Thermal modeling of a power ball grid array in system-in-package configuration

In power electronic designs, preliminary thermal analysis is essential when choosing packages and possible external heatsinks for energy thermal dissipation. In this paper, we describe a methodology for a simple development of a detailed thermal model for a fine pitch plastic Ball Grid Array (BGA) in System-in-Package configuration including one Bipolar-CMOS-DMOS (BCD) device, through the geometric and thermal properties of the power components and layers of the BGA under test. The validation of the proposed thermal model was carried out through a comparison of the simulation results with the experimental data obtained from the thermal analysis through an InfraRed (IR) camera. The absolute estimation error was less than 2°C for a maximum temperature within 100°C, and less than 4.5°C for temperatures above 100°C, with a temperature difference of the case around 50°C.