Preparation Of Thermal Conductive CE-EP And Study Of PCB Structure Thermal Property Analysis

The thin size and high power consumption of electronic products are beset by over temperature since it came into being, printed circuit board(PCB) as bridge among each electrical heaters should be the focus of enhancing heat dissipation research.The substrate with good heat dissipation performance could effectively reduce the failure of electronic products due to high temperature. Fabricating conducting circuit with printed electronic technology would avoid the waste of materials and save the cost. In this paper, the thermal proterty of the substrate and heat conduction material used for PCB substrate were studied.From material preparation aspect, the coupling agent(APS) was selected to modify aluminum nitride powders(AlN), alumina powders(Al2O3) and silica powders(SiO2). The surface profile of the samples were investigated by Scanning Electronic Microscopy(SEM) and Infrared Spectrography(FT-IR). The results showed that the surface of the inorganic filler have graft to APS successfully, and the surface treatment is good at the dispersion of the inorganic particles in the composite system. The modified AlN, Al2O3 and silica powders were separately mixed with the composite system. Three kinds of thermal conductive and insulating composites were prepared based on CE-EP blends, such as AlN/CE-EP, Al2O3/CE-EP, SiO2/CE-EP. Differential scanning calorimetry, thermal conductive tester, high-frequency meter, SEM and TG were used to analysis the properties of composites. The effects of the kind and filling content of inorganic particle on thermal stability, dynamic mechanical properties, thermal conductivity, electrical insulation and fracture toughness were discussed in detail. The results indicate that the appendent of three kinds of fillers can all enhance the thermal conductivity of composites, and the addition of three kinds of fillers can improve the curing of CE-EP and also can promote the fracture toughness and thermal stability of the composites. The results show that it can be used as conducting PCB material.From PCB structure aspect, three structures of PCB heat dissipations including the embedment of copper block under the chip(PCB-II), conjunction of the copper plate on the bottom(PCB-III) and the addition of Al plate(PCB-IV) were carried out FEM numerical analysis, including steady-state analysis, transient thermal analysis, heat resistance analysis and thermal analysis under different air heat convection coefficients, and compared to the common PCB(PCB-I)without effective heat treatment. The results indicate that PCB with three kinds of heat dissipation structures as PCB-II, PCB-III and PCB-IV successfully reduce maximum temperatures by 3.22 ℃, 7.86 ℃, 9.66 ℃ compared to the reference group PCB-I in the steady-state and transient thermal analyses. The temperature variation of PCB-III structure is the flattest among four kinds of PCB structures. The temperature gap between PCB-II and PCB-III is little within 10 s to 30 s and widen after 30 s. Heat dissipation effect of PCB-III is the best after the variation of convection coefficients, while the thermal dissipation effect of PCB-II tends to PCB-IV with the convection coefficient increase.