Development of practical thermal design technique of printed circuit boards for power electronics

In recent years, thermal design of electrical equipments including printed circuit board (PCB) is a key issue for developing electronics. Computational fluid dynamics (CFD) is widely used method for thermal design of electrical packages. Nowadays, heat generation density in electrical packages is increasing and PCB becomes one of heat dissipating path in electrical packages. However, considering complex wiring patterns on PCB, modeling of these wiring patterns is unrealistic work. Therefore, efficient thermal design technique is required for PCB. In this research, the effectiveness of the thermal design scheme that combines CFD analysis with thermal network method was examined. We measured the temperature distribution on PCB with several heaters experimentally and compared experimental results and temperature distribution from CFD analysis with variable thermal conductivities of PCB. Then, the thermal network model was applied to thermal analysis of PCB with the thermal conductivity value of PCB from CFD analysis. The results of thermal network model showed good agreement with the experimental results and it can be said that our thermal network model can be applied to thermal design of PCB. Furthermore, the influence of the heatsink height was examined by using our thermal network model of PCB.