A new phosphor thin film applied on Thin-Film-Flip-Chip Wafer-Level-Chip-Scale-Package

Abstract

In this paper a new type of thin-film-flip-chip wafer-level-chip-scale-package with phosphor thin film has been presented Phosphor films of 30um thickness with different packing density were used for packaging and the optical characteristics with increasing thickness by piling up phosphor sheet on one single chip-scale-packaging were studied The relative transmitted blue power decreases and the relative transmitted phosphor emission power increases as film thickness increases or packing density increases as well both reaching a saturated value For higher packing density the relative transmitted phosphor emission power also starts to drop after saturation The radiative conversion efficiency of the phosphor films starting from 66%~68% for 1 41 refractive index silicone and 64%~69% for 1 54 refractive index silicone decreases as the film thickness increases However radiative conversion efficiency of phosphor films with 1 41 refractive index silicone drops more quickly than 1 54 refractive index silicone The tendency of radiative efficacy is similar to the relative transmitted phosphor emission power the radiative efficacy increases and reaches a saturated value as phosphor film thickness increases For higher packing density the radiative efficacy also starts to drop after saturation with increasing film thickness The saturated efficacy value of the phosphor films with 1 54 refractive index silicone which is about 240 lm / O W is higher than that with 1 41 refractive index silicone which is about 225 lm / O W to 230 lm / O W However for the highest packing density said above 60% and the thinnest film thickness said 30um the phosphor film with 1 41 refractive index silicone has almost the same radiative efficacy which is 230 lm / O W as 1 54 refractive index silicone Finally the ACU of phosphor films with 1 41 refractive index silicone 30um and 76um film thickness and phosphor films with 1 54 refractive index silicone 32um and 108um film thickness was measured For thinner phosphor film thickness delta u’v’ of view angle is lower From the study a phosphor film with 1 41 refractive index silicone of high packing density said >60% and thin film thickness said 30um is more suitable for the thin-film-flip-chip wafer-level-chip-scale-package because it has high radiative efficacy close to that of 1 54 refractive index silicone and better angle of color uniformity furthermore the 1 41 refractive index silicone usually having better reliability than 1 54 refractive index

Date of Award	2016 Aug 25
Original language	English
Supervisor	Shoou-Jinn Chang (Supervisor)