標題: | Improved Performance and Heat Dissipation of Flip-Chip White High-Voltage Light Emitting Diodes |
作者: | Wu, Ping-Chen Ou, Sin-Liang Horng, Ray-Hua Wuu, Dong-Sing 電子工程學系及電子研究所 Department of Electronics Engineering and Institute of Electronics |
關鍵字: | High-voltage light-emitting diode (HV-LED);white LED;flip-chip LED;heat dissipation;luminous efficiency |
公開日期: | 三月-2017 |
摘要: | Three types of white light emitting diodes (LEDs) were constructed with 4 x 1 micro-cells. The first one is the convectional LED series connected with four cells using the wire-bonding process. The other two devices are 4 x 1 lateral-type and 4 x 1 flip-chip high-voltage LEDs (HV-LEDs) using the interconnection technique. The convectional LED, lateral-type HV-LED, and flip-chip HV-LED are denoted as C-LED, L-HV-LED, and FC-HV-LED, respectively. Moreover, the white LEDs were formed by combining the blue LED chips and the phosphor-dispensing method. The thermal resistances (at 20 mA) of C-LED, L-HV-LED, and FC-HV-LED were 14.5, 59.2, and 12.2 K/W, respectively. In addition, the surface temperatures (at 20 mA) of these three devices were 30.74-31.82, 65.93-68.95, and 27.01-27.96 degrees C, respectively. Obviously, the heat dissipation of L-HV-LED was much worse than that of C-LED. However, via the fabrication of the flip-chip structure, the heat dissipation of HV-LED can be enhanced significantly. At an injection current of 100 mA, the luminous efficiencies of C-LED, L-HV-LED, and FC-HV-LED were 80.8, 81.0, and 91.8 lm/W, respectively. Furthermore, at the same forward voltage, a higher current can be driven in the FC-HV-LED, leading to an apparent improvement in the luminous efficiency. According to our calculation, the emission size of HV-LED was only 84% compared with that of C-LED. On the other hand, the fabrication of HV-LED can be performed without the wire-bonding process. This indicates that the FC-HV-LED possesses not only lower production costs but also higher optoelectronic performance than that of the C-LED. |
URI: | http://dx.doi.org/10.1109/TDMR.2016.2646362 http://hdl.handle.net/11536/133145 |
ISSN: | 1530-4388 |
DOI: | 10.1109/TDMR.2016.2646362 |
期刊: | IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY |
Volume: | 17 |
Issue: | 1 |
起始頁: | 197 |
結束頁: | 203 |
顯示於類別: | 期刊論文 |