| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 100 === In this research, using thermo-sonic bonding technology, the chip LED and the sub-mount are bonded to produce a flip-chip power LED with high thermal conductivity Au bumps (291W/mK). The PLED usually exhibits an area of larger than 1mm2 , its power consumption is greater than 1 watt, therefore the FC LED structure here we proposed can let the heat sink rapidly to improve the heat dissipation problem and enhance the luminous efficiency.
Four different LED electrode patterns are prepared for FC bonding, after the whole FC LED fabrication process are accomplished, IV & LI characteristics, integration sphere measurement and thermal image analysis etc., are adopted t to analyze their experimental results. The data showed that FC LEDs have the luminous efficiency 22.7% higher than non Flip-chip LED at 350mA, the flip-chip LED with reflector’s luminous efficiency is 42.6% higher than the flip-chip LED without reflector. Thermal characteristics show that the Au bump number is proportional to the thermal dissipation ability, but with a saturation at the Au bump reach the number of 20~24. Thus, even through the entire flip-chip LED with 28 ~ 36 Au bumps, due to the bonder can’t provide enough bonding force, result in a poor FC LED electrical and thermal characteristics.
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