@inproceedings{ae81c1bba0b64b95a5b5232dd453edad,
title = "Directly Determining the Coefficient of Thermal Expansion of High-power Light-emitting Diodes by Optical Coherence Tomography",
abstract = "The coefficient of thermal expansion (CTE) is a physical quantity that indicates the thermal expansion value of a material upon heating. For advanced thermal management, the accurate and immediate determination of the CTE of packaging materials is gaining importance because the demand for high-power lighting-emitting diodes (LEDs) is currently increasing. In this study, we used optical coherence tomography (OCT) to measure the CTE of an InGaN-based (λ = 450 nm) high-power LED encapsulated in polystyrene resin. The distances between individual interfaces of the OCT images were observed and recorded to derive the instantaneous CTE of the packaged LED under different injected currents. The LED junction temperature at different injected currents was established with the forward voltage method. Most importantly, this work validates the hypothesis that OCT can provide an alternative way to directly and nondestructively determine the spatially resolved CTE of the packaged LED device, which offers significant advantages over traditional CTE measurement techniques.",
author = "Yeh, {Ting Wei} and Chou, {Chun Yang} and Huang, {Chun Ying} and Yao, {Yung Chi} and Haung, {Yi Kai} and Tsai, {Meng Tsan} and Lee, {Ya Ju}",
note = "Publisher Copyright: {\textcopyright} 2018 OSA.; 2018 Conference on Lasers and Electro-Optics, CLEO 2018 ; Conference date: 13-05-2018 Through 18-05-2018",
year = "2018",
month = aug,
day = "6",
language = "English",
isbn = "9781943580422",
series = "2018 Conference on Lasers and Electro-Optics, CLEO 2018 - Proceedings",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
booktitle = "2018 Conference on Lasers and Electro-Optics, CLEO 2018 - Proceedings",
}