Browsing by Author "Chiang, Song-Bor"

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A NOVEL LIQUID-PACKAGING TECHNOLOGY FOR HIGHLY RELIABLE UV-LED ENCAPSULATION
(2019-01-01)
Zhang, Wen-Hua
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Lin, Wei-Keng
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Yeh, Chih-Ting
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Chiang, Song-Bor
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Jao, Chih-Sheng
This paper proposes a liquid-packaging technology for UV LED. Unlike the traditional packaging methods that involve thermosetting silicon or quartz glass, the proposed method primarily uses silicon oil to directly contact the chip, which prevents erosion due to moisture or oxygen. In this study, UV LEDs with high heat dissipation technology were selected, and the experimental results of optical and thermal management were compared between the general packaging and liquid-packaging structures, respectively. The results of the optical experiments showed that the proposed method increases the extraction efficiency by 9.5%. The results of the heat dissipation experiments showed that the liquid-packaging technology can reduce the thermal resistance of the UV-LED package by 31%.
An experimental study on the heat dissipation of LED lighting module using metal/carbon foam
(2013-11-01)
Yang, Kai-Shing
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Chung, Chi-Hung
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Lee, Ming-Tsang
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Chiang, Song-Bor
;
Wong, Cheng-Chou
In this study, thermal performance of the cooling modules applicable for Par 38 light bulb is investigated. A total of six heat sink modules, including the basic reference design, metal foam, and carbon foam are tested and compared. Tests are performed and analyzed using the transient test method based on JESD51-1 standard. It is found that the thermal resistance from junction to die attach is quite small. By contrast, the thermal resistance of the heat sink dominates the total resistance, and it comprises 55% of the total resistance for the standard heat sink module. With some slight opening on the base plate, the thermal resistance can be improved by approximately 12%. The thermal resistance for the carbon foam having an embedded metal plate shows the least thermal resistance of 1.14 K/W, followed by the carbon foam, and then the metal foam. The lower thermal resistance of carbon foam in association with copper metal foam is due to its higher emissivity. In addition to better heat transfer performance as compared to the standard plate heat sink, the utilization of carbon foam and metal foam can also significantly reduce the weight of the heat sink. In this study, the weight of the heat sink can be reduced as much as 33%. (C) 2013 Elsevier Ltd. All rights reserved.
Multispectral mixing scheme for smart LED-based lighting system
(2012)
Chiang, Song-Bor
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Chien, Ming-Chin
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Tien, Chung-Hao
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光電工程學系
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Department of Photonics
LED cluster is probably the most relevant among the emerging solid-state lighting techniques. Impressive scenarios of a wide range of color quality and luminous efficiency have been obtained, mostly at the condition of constant ambient temperature. This paper removes the constraint in ambient temperature. We present a methodology analogous to a general lens design rule to optimize step-by-step the spectral power distribution of a white-light LED cluster. The scheme enables the users to determine the optimal operation to meet requirements such as light efficiency, color quality, or other figures of merit over a wide range of color temperatures. All main factors influencing the spectral power distribution (SPD) are discussed, alongside the implementation of a pentachromatic R/G/B/A/CW platform suitable for clinic use. The result shows the multispectral cluster can be modulated within the color temperature from 2800K to 8000K in the range ambient temperature (10 degrees C similar to 100 degrees C) with high color quality scale (CQS > 85 points) and the possibly highest luminous efficiency.