Study of white epoxy molding compound for LED bracket

Epoxy molding compound for LED bracket, with the merits of good resistance to heat and light damage as well as good reliability and warpage compared to traditional thermoplastic reflecting materials for LED bracket, such as Polyphthalamide (PPA) and Poly1,4-cyclohexylene dimethylene terephthalate (PCT), has becoming the focus of researchers. Here we studied the reflectance of the white epoxy molding compound from the aspect of epoxy resin, type of titanium dioxide, wax and wetting and dispersing additives. And the results disclosed that epoxy resin A with the structure in Fig.1 exhibited higher reflectance at 450nm after aged at 150 for 1000h with the value of 70% while epoxy resin B with the structure in Fig2. With the value of 50%. At the same time, epoxy resin A displayed higher water absorption than epoxy resin B. Meanwhile, the reflecting material titanium dioxide modified by silica, alumina as well as organics disclosed highest reflectance, and then is the titanium dioxide modified by silica and alumina, and the last one was that only modified by silica or alumina. Wax showed no significant difference on the reflectance due to the tiny addition. When it comes to the wetting and dispersing agent, with the increasing of the content of polyester type wetting and dispersing agent, the reflectance of the white epoxy molding compound decayed.