Preparation And Anti-ultraviolet Aging Performance Of Modified Epoxy Resin For LED Display Packaging

Epoxy resin was widely used in LED packaging,due to its excellent performance. Epoxy resin turns yellow and ages and cracks easily under illumination of ultraviolet light for a long time, so that the service life on LED screens will be reduced. It is necessary to modify epoxy resin to improve its ultraviolet aging resistance. There are a lot of reports on modification of epoxy resin with organic ultraviolet screening agents or pure inorganic nanoparticles.However, research on epoxy resin modified with two or more kinds of particles has been rarely reported. Some inorganic semiconducting particles can cause degradation of organic matters because of its strong photocatalytic performance.The photocatalytic performance of particles can effectively be weakened after treatment with UV-inactive inorganic films. There are few reports on modification of epoxy resin to improve its anti-UV aging properties. In this research, epoxy resin was modified with pure particles, composite particles and silicon coated TiO₂, respectively. The modified epoxy resin was mainly applied to integrated LED encapsulation.The main research contents include the following aspects:?1? The epoxy resin was modified using nano TiO₂, nano ZnO and TiO₂/ZnO composite particle respectively. Visible light transmittance, ultraviolet absorption, yellow degree coefficient and structural properties were investigated using UV-Vis and Infrared spectrophotometers. It is showed that the anti-UV aging and UV shielding properties are significantly improved with a high visible light transmittance after modified by 0.06% TiO₂, 0.06% ZnO and 0.02% TiO₂ +0.04% ZnO respectively.?2? Photocatalytic properties of TiO₂ and ZnO accelerate degradation of epoxy resin. Photocatalytic shielding ability is obtained after coating with silica.Properties of silica coated TiO₂ is investigated with XRD, SEM, particle size analysis, infrared spectra, and degradation of methylene blue. The influence of heat treatment temperature and the amount of coating were also studied. It is showed that TiO₂ coated twice with 10 wt% SiO2, has a strong catalytic shielding capacity, which be treatmented by 100? heat. Simultaneously, it also has a strong ability of ultraviolet absorption. It is showed that the anti-UV aging and UV shielding properties are significantly improved with a high visible light transmittance after modified by TiO₂ coated with 0.06% and 0.09% silica.?3? In order to meet the requirements of industrial production and practical applications, waterproof and packaging of the epoxy resin were studied. It is showed that the modified epoxy resin has excellent waterproof properties with a level of IPX8, large water contact angles, and relatively a long operation time of half hour for packaging.