Study On The Electrical And Thermal Capability Of Laminated Composite Materials

With the development trend of light and filmy, the flexible samdwich composite and the resistance foil composite material for plane resistor were made. The electrical and the thermal capability were also studied. It was selected as aim as to reduce the thickness of the flexible resistance film. The resistance temperature coefficient of resistance foil composite material was restricted. The thickness of the flexible resistance film could be less than 100μm. It was also less than the same type products. The high thermal conductive and insulating adhesive could enhance the axial thermal conductibility of the planar resistance, and increase the power. But the axial thermal conductibility of the traditional planar resistance was poor.The flexible resistance film was made by using chemical etching technics of PCB. It indicated that the thickness of sensitive printing ink should be thin. The redox potential of etchant increases as the increasing of etchant concentration. The etching rate increases as the increasing of concentration at first, and then descends. The maximum of rate appears about at the concentration of 40%. The etching rate increases as increasing of temperature and decreasing pH. But at 40~50℃, the effect was the best. The FeCl3 solution was disabled when the concentration of alloy in it was bigger than 65g/L.The effect of Fe - Ni, reaction temperatures, reaction time and acidity of solution on regeneration of spent FeCl3 solution were studied. The redox potential of spent FeCl3 solution could reach 95% of fresh solution with the conditions of high surface activity of metal iron powder, higher reaction temperature, reaction time about at 60min, pH around 4 and the ratio of Fe - Ni is 1~3. The FeCl3 solution in which nickel ions are removed off can be reused.It was discovered that the resistance temperature coefficient of is smaller than that of bare resistance. Because the resistance foil was affixed with insulated film. It indicated the thermal expansion is restricted by the insulated film. The polyurethane film could endures the most power consistency and tiptop temperature are 1.768 W / cm2 and 271℃. But the most are 0.46 W / cm2 and 213℃for mylar.The thermal conductibility of SiC powder with the different grain diameter was investigated. The thermal conductibility of the proportioning which includes 60% -W100, 20% W63, 20% W28 is the most. It is 0.5141 W/m·K. The SiC powder is modified by titanate coupling agent, then is dispersed in epoxy resin (EP) system. The thermal conductibility of it improves when the volume mark increasing. But the thermal expansion coefficient and the resistive curly intensity is descended. So, the thermal conductibility, the thermal expansion coefficient and the resistive curly intensity of the best sample can reach 5.83 W/m·K, 13.9×10-6/℃and 105MPa.