Effect of silicone resin modification on the performance of epoxy materials for LED encapsulation

Cycloaliphatic epoxy resin was modified by phenyl methyl silicone resin to investigate the influence of silicone content on the performance and reliability of epoxy packaged light-emitting diode. The silicone modification of epoxy encapsulants was characterized by transform infrared (FT-IR) spectrophotometer. Rotational rheometer was used to study rheology behavior. Differential scanning calorimetry, thermogravimetric analyses, dynamic mechanical analysis, thermomechanical analyzer were introduced to measure the thermal and mechanical properties. Ultraviolet visible spectrophotometer was utilized to study heat and ultraviolet resistance. In reliability test, scanning acoustic microscope and scanning electron microscope were applied to observe interfacial delamination. Water sorption process was monitored using gravimetric measurement. FT-IR study shows a chemical bonding between hydroxyl group of silicone resin and epoxy resin. With the incorporation of silicone resin, favorable properties were obtained such as higher thermal decomposition temperature, lower equilibrium water sorption, and better heat and UV resistance. Among these systems, 10% silicone modified epoxy resin exhibits the best performance in reliability test.