Study on die-bonding key technology of UV LED packaging

Due to its potential market value, the packaging and application technology of UV LED are paid more and more attention. In this paper, the die-bonding interface and thermal resistance of UV LED were investigated by using different TIMs, and the influence of junction temperature on photochromic properties was studied. The results show that the traditional silver glue as a thermal interface material has the highest junction temperature, and its advantage is that it is cheap. Compared with SnAgCu solder, Nano Ag paste has better thermal conductivity and better thermal stability, but the price is higher. Moreover, the reflow process of Sn based solder is more mature. Compared with AuSn and SnAgCu solder, the research results show that the problem of solid-state interface of Sn based solder is poor thermal stability. Under the action of electric stress and thermal stress, the interface will have atomic migration. After high temperature aging, the interface of AuSn solder-boning interface even has serious atom migration and relatively large voids. The study indicated that with the increase of junction temperature, the radiation power and photochromic characteristics of all tested samples decrease.