A novel molding process for wafer level LED packaging using uniform micro glass bubble arrays

Light Emitting Diodes (LEDs) as an emerging light source has been rapidly developed due to its considerable advantages including high energy efficiency, extremely long life and environmentally friendly. Since packaging accounts for the major part of the total cost, a novel molding process for wafer level LED packaging will be presented in this paper, which could decrease the total cost by the wafer level process. The packaging was performed using micro glass bubble arrays combined with silicon substrate. The micro glass bubble arrays were prepared using Pyrex 7740 glass wafer by a WLP chemical foaming process which was suitable for volume production of micro glass bubbles. In addition, the uniformity of the packaged micro glass bubbles were characterized by SEM, which shows a good uniformity of the micro glass bubbles. The experimental results showed a brilliant application prospect in wafer level LED packaging as well as other semiconductor devices using the uniform wafer level micro glass bubble arrays.