Patent attributes
An underfill formation technique for LEDs molds a reflective underfill material to encapsulate LED dies mounted on a submount wafer while forming a reflective layer of the underfill material over the submount wafer. The underfill material is then hardened, such as by curing. The cured underfill material over the top of the LED dies is removed using microbead blasting while leaving the reflective layer over the submount surface. The exposed growth substrate is then removed from all the LED dies, and a phosphor layer is molded over the exposed LED surface. A lens is then molded over the LEDs and over a portion of the reflective layer. The submount wafer is then singulated. The reflective layer increases the efficiency of the LED device by reducing light absorption by the submount without any additional processing steps.
