Preparation And Performance Of Silicone Materials For LED Encapsulation

Compared with the traditional lighting source, light emitting diode (LED) hasmany advantages, such as efficient energy saving, environmental protection and longlife. It has become a new generation of lighting source. It is one of the hightechnologies with social significance and economic value in the21st century. With theimprovement of the manufacturing technology, brightness and power, LEDencapsulating material was put forward higher requirements. The LED encapsulatingmaterial of good performance depends on import in domestic market, which hindersthe smooth implementation of semiconductor lighting project with independentintellectual property. Based on this situation, two kinds of LED encapsulating siliconematerials were prepared by the method of addition curing and epoxy phthalicanhydride curing, and their properties have been characterized.Additional liquid silicone rubber with excellent thermal resistant, aging andyellowing resistant properties is the ideal material for LED encapsulation. In order toinvestigate the influence of crosslinking agent, hydrogen content, vinyl silicone oiland Si-H:Si-Vi value on the properties of additional liquid silicone rubbers, additionliquid silicone rubbers with low refractive index (unfilled), low refractive index(filled), high refractive index (low vinyl content silicone resin) and high refractiveindex (high vinyl content silicone resin) were prepared through the design of formulain this paper, and the mechanical properties, adhesion and transmittance have beeninvestigated. The results have certain theory value and application value.Currently the epoxy resin and the organic silicone materials are used mostly inLED encapsulation. In order to possess both advantages of these materials, highrefractive index silicone-modified epoxy resin containing phenyl and epoxy groupswas prepared by condensation polymerization reaction using KH560anddiphenylsilanediol (DPSD). The influences of reaction factors such as catalyst,reaction temperature, reaction time and phenyl content on the organic siliconematerials were investigated. The preferred reaction conditions were determined andthe structure of material was characterized by FT-IR and1H NMR. The thermalresistant properties and mechanical properties of transparent organic siliconeencapsulating materials were investigated after using hexahydro-4-methylphthalicanhydride (MeHHPA) as curing agent. The results showed that the organic siliconeencapsulating materials had high refractive index (1.547), high transmittance (95%), excellent adhesion, good heat resistant and mechanical properties. This high refractiveindex organic silicone materials containing phenyl and epoxy groups might be appliedfor LED encapsulation.