A novel process obtaining silicone dome lens for wafer level LED packaging

This study presented a simple and high-efficiency process achieving dome silicone lens for wafer level LED arrays. In this process silicon wafers acted as the substrates of LED chips. The translucent silicone ring directly dispensed on the silicon wafer served as the border to confine the spread of the silicone encapsulant. The geometry of the silicone lens can be adjusted by controlling the volume of the silicone encapsulation. This process has three obvious characteristics: (1) it can enhance the side light extracting rate via the transparent dome silicone lens and the translucent silicone ring; (2) can achieve the dome silicone lens and the silicone ring without any mould applied in traditional package process; (3) can be used to achieve dome lens, which can reduce the cost and time of production. The measurement results revealed a large variation range of level angle which is from 45° to 130°. The volume of silicone encapsulation ranged from 9mm³ to 17 mm³ when the level angle of the lens was from 90° to 130°.