The consideration about “heat” in PCB designThe consideration of EMC, thermal conduct and anti-liberation for PCB layout is more important, especially for designing minimum size,，standard，modularization and puzzled commercial products with high power. This will benefit the qualification and reliability of the product.This article presents the study of thermal dispersion for PCB layout design. The method of theoretical calculation and testing analysis for PCB structure, PCB layout, trace width and copper weight and material selection are also introduced.This artical is expected to be useful for the PCB designersKEYWORD:Heat-conduct structure ， thermal-conduct material ， current load， temperature rise ， thermaldispersion