Evaluating Joule Heating Effects and Electrical Current Flow Through Copper Layers Inside PCB Using Finite Element Analysis

The increasing complexity of electronics, particularly in the automotive industry, demands effective thermal management for multilayer Printed Circuit Boards (PCBs). Traditional analysis methods often involve simplifications. This study utilizes Finite Element Analysis (FEA) with Siemens Simcenter FLOEFD to simulate current distribution, the Joule heating effect, and thermal behavior in a simplified 4-layer PCB CAD model subjected to a 7A DC current. A mesh independence study confirmed the reliability of the results. The initial simulation revealed non-uniform current density, highlighting underutilized copper areas in trace corners and vias. Based on these findings, the CAD model was optimized by strategically removing these low-current-density regions, achieving a total copper volume reduction of approximately 13% (35% for vias). Re-simulation of the optimized model showed an increase in maximum temperature by about 8°C (a ~10% relative increase) and a ~6% rise in total dissipated power, attributed to higher current density in the remaining paths. FEA is demonstrated as an effective tool for identifying PCB design optimization opportunities and quantifying the trade-off between material cost reduction and thermal performance.