Estimation of Heat Generation in Semiconductors Centrally Mounted on Printed Circuit Boards

This work proposes a method to estimate the heat dissipation of components that are centrally soldered to printed circuit boards (PCBs). The power losses of a ball grid array (BGA) package and a MOSFET are estimated via a 1-D thermal model in tandem with a heat flux sensor. The former device is soldered to a multilayer PCB with complex copper traces, whereas the latter is mounted on a PCB without internal copper layers and relatively simple trace patterns. Thermal analyses demonstrate that the 1-D model is capable of representing heat conduction with good agreement in the board without internal copper layers. However, the multilayer PCB requires an adjustment coefficient based on the thermal conductance of the board. Said coefficient is employed to adjust the effective heat transfer coefficient of the multilayer PCB. With the aid of the adjustment coefficient, results show that the 1-D thermal model in combination with a heat flux sensor is capable of predicting heat dissipation within 15% of the actual power loss for both devices.