Researh On The Packaging Characteristics Of Led Flip-Chips

LED packaging can protect the LED chip from the mechanical, thermal,moisture and other external shocks, and meet the requirement of the LED light colorfeature.In this paper, we focuses on the packaging of flip-chip LED. By studying itsopto-electric properties and aging properties. The results show that the white flip-chipLED package die-bonded with low temperature solder paste has the lowest colorcoordinates and the highest color temperature. The color coordinates and colorrendering index of flip-chip LED package increase with the increase of dispensingtime, and the color temperature and light efficacy decrease with the increase of thedispensing time. With the increase of electrical current, the color coordinates andcolor rendering index of flip-chip LED package is slightly reduced, while colortemperature and luminous flux increase with the increase of the electric current,luminous efficacy decreases with the increase of the electric current. In the earlyaging, luminous flux and luminous efficacy of flip-chip LED package will slightly goup at first, and then go down. With the increase of aging time, the dominantwavelength and color coordinates slightly decrease, while the color temperature rises.Analysis shows that the lumens reduction is mainly due to the aging of the phosphor.