As the chip integration level increases and the chip power consumption density increases, reducing the internal thermal resistance of package becomes the main consideration of thermal design. Currently, the widely used HFCBGA is a thermally enhanced FCBGA mounting a metal heat spreader on the back of the chip through thermal interface materials(TIM), which is applied with various high-heat-conducting filler. Selecting a highly thermally conductive TIM is already a key thermal performance index to reduce thermal resistance of junction to case. Through these series of studies, We found that one TIM material is an effective method to solve the heat dissipation problem and have also been qualification.