This study proposes a novel packaging structure for vertical thin-GaN LED applications by integration of LED chip and silicon-based packaging process. The vertical thin film LED is directly mounted on package submount. The shortest thermal path structure from junction to package submount achieves the lowest thermal resistance of 1.65 K/W for LED package. Experimental results indicate that low thermal resistance significant improved forward current up to 4.6A with 1.125 × 1.125 mm² LED chip size.

This letter proposes a novel electrode structure for thin-GaN LED applications. The structure enhances light extraction and wall-plug efficiency in thin-GaN LEDs. To enhance light extraction in thin-GaN LEDs and solve current crowding effects caused by electrodes composed of metal, conventional n-GaN electrodes were replaced with ITO conductive films because of their high optical transparency. Simulation results show that the thin-GaN LEDs that use ITO as the nonshielded electrode have a more uniform current density distribution on the n-GaN surface and a higher average internal quantum efficiency than conventional metal electrodes. Furthermore, when a current of 200 mA was applied, the thin-GaN LEDs using the proposed electrode had a 40% increase in light-output power and a significant decrease in chip temperature compared to the use of conventional electrodes. The results indicate that the nonshielded ITO electrode design enhances the light extraction efficiency and avoids the accumulation of heat because of its uniform current density distribution.Index Terms-LED, nonshielding electrode, thin-film package LED (TFP LED).

In this paper, the selective induction heating technology is applied to glass-glass and glass-silicon solder bonding for MOEMS (optical MEMS) packaging. The Ni bumping with a buffer layer is successful to release the thermal stress for avoiding delamination. The Au wetting layer must be thick enough to prevent from being solved entirely into Sn, and it will improve bonding strength. The bonding specimens are soaked into 25°C water and placed into 85°C/85% RH oven, respectively. No moisture penetrates into the cavity after 1 day in both test conditions. In the test condition of 125°C leakage-test liquid (Galden HS260), no bubble is observed. The lowest bonding strength is 3 MPa.