The Thermal Particle Sintering And Composite Orientating For The Heat Dissipation Influence Of High-power LED

With the development of LED technology, how to improve its life has become an important issue. The accumulation of heat generated by LED chip can shorten its life, so the low thermal conductivity of packaging material is one of the biggest challenges in the development of LED. Thus improving the thermal performance of LED packaging materials becomes a pressing problem of the day. Currently encapsulating material available to solve the problem is to fill the thermally conductive particle to polymer, prepare the high thermally conductive polymer composite.The thermal conductivity of polymer matrix composites has a relationship with a number of factors. The relevant factors are divided into two aspects of thermal particles and the polymer. Thermally conductive particles comprise thermal conductivity itself, shape, size, addition amount, dispersibility, orientation, interfacial bonding interface area, species. Polymers include thermal conductivity, orientation and so on. In order to solve the problem of heat dissipation of LED encapsulating material, the subject epoxy resin as the matrix, respectively, silica(Si O2), silicon carbide(Si C) as thermally conductive fillers, thermally conductive particles were prepared by a high proportion of ceramic sheets and a high thermal conductivity polymer alignment type based composite, a high proportion of thermally conductive ceramic particles are used in the ceramic LED package in it, and oriented type composite are used as an adhesive layer in the LED.In order to improve the interface between the thermal conductivity of the particles and the epoxy matrix, the subject of the thermally conductive particles with a silane coupling agent surface treatment, and the mechanism of silane coupling agents carried out a detailed analysis of the results showed that surface-modified thermally conductive particle filled epoxy, thermal conductivity of the composite material to be prepared is higher than the unmodified composite. Preparation of thermally conductive particles in a high proportion of the ceramic sheet in the process, with a 5% by mass of the thermally conductive particles of aluminum(Al) or yttrium oxide(Y2O3) as a sintering agent, by high-pressure forming, in a high-temperature sintering furnace 660 ℃, the study found yttrium oxide(Y2O3) as a sintering agent can make the film thermal conductivity ceramic particles in epoxy resin for maximum density, thermal conductivity is prepared to achieve high-density low-temperature co- fired ceramic pieces. By an optical microscope ca n clearly see with aluminum powder(Al) made of a sintered ceramic sheet porosity agent to make significantly more than yttrium oxide(Y2O3) ceramic sheets sintering agent.This paper starts from the polymer orientation mechanism to study the relationship between the glass transition temperatures of the polymer orientation between. In order to make the composite material having orientation, thereby enhancing the thermal conductivity of the composite material, in the subject by measuring the glass transition temperature of the composite material is to master the temperature and time of orientation, the orientation of the composite material to mechanical stretching occurs, the prepared orientation composites. Can be observed by an optical microscope cross-sectional area of different orientations composite fiber, research and found that the thermal conductivity of the composite material orientation ratio of the thermal conductivity with increasing addition of fine particles increases. Thermal conductivity of the composite material is higher than the alignment unoriented composite, the thermal conductivity of the composite material with increasing orientation draw ratio increases.The thermal conductivity of 80wt% Si O2 with the draw ratio of 4 is 1.2 W/(m K), which is about 5.97 times that of the epoxy resin. And a thermal conductivity(K∥),28.8 times that of pure epoxy resin, is obtained with 60wt% micro-Si C and a draw ratio of 4.In this issue also on the Si O2/epoxy orientation dielectric properties of the composites are tested, the test results show that the influence of the orientation of the epoxy resin insulation performance is not great.