Optimization of hotspot location on multi stacked board of mobile phone

As the performance of smartphones increases rapidly, the power required by major components has increased. To maximize usage time in power demanding scenario, phone makers are reducing number or size of component by merging parts to secure maximum battery space within a limited smartphone size. Also, dual stack and triple stack of PCB is introduced to increase the mounting area while reducing the area occupied in smartphone. This complicate thermal coupling between components on multiple stack of PCB intensify hot spot problem. In this paper, we analyze the heat dissipation environment of various latest board floor plans. The optimal arrangement of hotspot components (application processor, modem, 5G antenna, camera) is discussed by heat path analysis of hotspots in the multiple mounting environment. Also, we introduce EAS (Effective Area for heat Spreading) to find optimal PCB shape in limited PCB area. The case study of triple stack structure result shows that main heat source should be located near set heat spreader and main board. Also, PCB hole need to be located at the edge of PCB to maximize effective area for heat spreading.