| Summary: | 碩士 === 國立臺灣科技大學 === 光電工程研究所 === 106 === The purpose of this study is to analyze the carrier transport and recombination mode of three wavelength chips through the relationship between LED electrical characteristics and spectral changes, and the three wavelength chips studied will be applied to the poly fish lamp by multiple chips structure with phosphor powder. The water cooled LED tube is used as the structure to simulate the heat dissipation effect.
The three wavelength chips are ultraviolet light, violet light and blue light, respectively. First of all, import by using pulsed current, analysis of three wavelength chips electrical characteristics. Spectral measurement by integrating sphere. Experiments show that as the current density increases, the three wavelength chips exhibit unequal blue shift and tunneling. In addition, there are the phenomenon of extra peaks in the three wavelength chips. The above phenomenon is explained by (Thermionic trap-assisted tunneling; TTAT) and (Density-Activated Defect Recombination; DADR).
This study verifies that the water cooling method has the effect of dissipating heat. We use multiple chips structure. The phosphor blend is mixing transparent resin with yellow and green phosphors. To optimized the fisheye coverage spectrum and white light source, the concentration of phosphors blend layer is adjusted by means of Taguchi Method. The single LED has a coverage ratio of 83.58%, a white correlated color temperature of 8418 K, and a color rendering index of 70. Simulated water cooled lamp cooling structure and compared with experimental results. Compare the degree of heat dissipation by changing the current, water flow rate and lead-frame spacing. The results show that adjusting the water flow rate and the arrangement of the lead-frame can effectively reduce the overall thermal resistance of the water cooled tube.
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