| Summary: | 碩士 === 國立中興大學 === 精密工程學系所 === 104 === High voltage ultraviolet light emitting diodes (HV-UVLEDs) with high efficiency is developed in this thesis. In general, the fabrication process is complicated and the breaking off wire between sub cells is difficult to prevent for traditional HV-LEDs. In this thesis, polymer material is used to fill-trench with planarization and interconnection technology is also applied on metal layer connection to fix wiring defect issue. Using the interconnect technique, 16 microchips are connected to form HV-LEDs, chip size: 61 mil x 33 mil. Five different space between microchips, 40, 50, 60, 70, and 80 μm, respectively, are developed and compared with traditional high performance UV LEDs( HP-UVLEDs) in this thesis.
Five different kinds chip spacing of HV-UVLEDs were fabricated via the electrode pattern, ohmic contact, and arrangement of chip spacing. The leakage currents (@-60 V) of these five kinds HV-UVLEDs were less than 1 μA. The luminous output power and wall-plug efficiency of HV-UVLED, which is with 50 μm spacing, is 269.6 mW and 23.2 % as forward current is 20 mA. Compared with the other four kinds HV-UVLEDs the luminous output power of HV-UVLED with 50 μm spacing is raised 13-27% enhancement.
To compare LEDs structures, this thesis includes HV-LEDs and traditional HP-LED. As input power is set 1.2 W, the luminous output power of HV-LEDs and HP-LED were 269.6 mW and 210.1 mW, respectively. To compare with HP-LED, luminous output efficiency and wall-plug efficiency of the HV-LEDs enhanced about 28.3 % and 40.6 %, respectively. Surface temperatures of HV-LED and HP-LED is about as 40.1 oC and 54.4 oC, respectively.
In summary, a 60V HV-UVLEDs module is developed in this research. HV-UVLED with 50 μm spacing is with very well performance, higher luminous output power, wall-plug efficiency, and heat dissipation. Moreover, the disadvantages of traditional HP-UVLEDs are not existed on the new HV-UVLED. In the other word, the HV-UVLEDs technology developed in this research has big potential in UV-LED area.
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