Preparation and properties of vinylphenyl-silicone resins and their application in LED packaging

Abstract

Three types of vinylphenyl silicone resins, vinyl-terminated, vinyl-capped, vinyl-terminated and vinyl-capped silicone resins, were synthesized through co-condensation and poly-condensation methods, and were characterized by nuclear magnetic resonance spectroscopy (¹H NMR, ²⁹Si NMR) as well as Fourier transform infrared spectroscopy (FTIR). The cured phenyl-silicone resins were characterized by thermogravimetric analysis (TGA), a electron universal testing machine at different temperatures, spectrophotometry, and transmission electron microscopy (TEM). The TGA results indicated that the thermal stability of cured phenyl-silicone resins prepared from the vinyl-terminated silicone reins was better than that of vinyl-capped silicone resin. In addition, all of these cured phenyl-silicone resins exhibited an onset decomposition temperature higher than 500 °C. The values of elongation at break were above 20% at −40 °C, indicating that these materials possessed a certain toughness at a relatively low temperature. The results of TEM revealed that the materials with a higher homogeneity degree of morphological structure could obtain 98.7% transmittance at a wavelength of 680 nm. Reliability tests, including a dye test, thermal shock test, and wet and high temperature operation life (WHTOL) test, demonstrated a wide range of applications of these materials in LED packaging.