Measurement and Analysis of Patterned Phosphor Films for LED

The white light emitting diode (LED) has become the most popular lighting for the next generation. The department of energy (DOE) of the United States has stipulated the standard of luminaire that the spatial angular color deviation (SACD) should be less than ±100K and the SDCM (standard deviation of color matching) needs to be smaller than 2 since 2015. However, the traditional phosphor dispensing method suffered the problems of huge SACD, large batch color shift, phosphor sedimentation and so on. Many processes of phosphor films have been mentioned to replace the traditional phosphor dispensing method so far, but not yet established systematic analysis and measurement methods after production. In this thesis, we developed a measurement system for the phosphor film by using Prometric 9 (PM9) and a homemade blue backlight, and verified and regulated by using the spectrometer measurement method. We manufactured the matrix type of patterned phosphor film with the same thickness and uniformity by molding process, and succeeded to measure the SDCM of phosphor film of each small piece to be less than 2. In addition, white LED we made by the small pieces of patterned phosphor film bond to the vertical blue chip, which reduced the problem of SACD due to no side light leak and uniformity of phosphor film. Finally, we attempted to explore the optical properties of bonding layer by simulation, and found that the bonding layer with size variation will dominate the optical properties of the encapsulation.