Optical characterization of a light bulb with the waffle pack LED WLP module

As the emergence of solid state lighting, light emitting diodes (LEDs) have been developed for applications of tremendous usage. For indoor lighting, LED light bulbs share large portions of market. The chip on board (CoB) package is a very attractive architecture for high brightness LEDs which can lead improved price competiveness, package integration and thermal performance. Waffle pack LED packaging technology has been proposed based on wafer level packaging (WLP) technology and remote phosphor configuration. The package has a huge potential for mass production and cost reduction. However, so far there were few optical results reported. In current study, photometry tests of both the component and light bulb were made. Optical indices such as luminous flux, CCTs and near field / planar light distributions were measured. The package was compared with the commercial CoB module. A ray tracing tool was used for helping experimental validation. The results showed that the waffle pack produces white light with improved angular color uniformity. The two components have similar lighting distributions, and waffle pack produces higher optical output than traditional CoB package.