Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes

The project signifies thermal and optical characterizations of pre-molded and ceramic package light emitting diodes (LEDs) that are conducted by using thermal transient and light emission recording techniques. It was observed that the luminous intensity of the LEDs is dependent on the input current....

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Main Author:	Lee, Zhi Yin
Format:	Thesis
Language:	English
Published:	2013
Subjects:	QC1 Physics (General)
Online Access:	http://eprints.usm.my/45102/1/Lee%20Zhi%20Yin24.pdf
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spelling	my-usm-ep.451022019-07-31T07:54:40Z Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes 2013-07 Lee, Zhi Yin QC1 Physics (General) The project signifies thermal and optical characterizations of pre-molded and ceramic package light emitting diodes (LEDs) that are conducted by using thermal transient and light emission recording techniques. It was observed that the luminous intensity of the LEDs is dependent on the input current. However, the LEDs efficiency is reduced for about 15% with the current increases, which due to the high current density and heating of LED junction. In terms of package-level and system-level, pre-molded package LED shows approximately to 13% and 15% lower in junction-to-case and junction-to-ambient thermal resistances respectively than ceramic package LED. Despite, the heat dissipation of ceramic package LED is improved after mounting on a metal-core board (board-level). Here, the effects of packaging material properties and ratio of contacting surface area are applied. Next, the results shows that the application of thermal compound as thermal interface material yields about 6% lower junction-to-ambient thermal resistance than thermal tape. Further investigation shows that the optimum heat convection for pre-molded package LED in an open-air environment is obtained as the cooling fan facing upward; while in terms of still-air environment, it is achieved as the cooling fan facing downward. Lastly, the accuracy of the captured thermal transient is improved by considering the optical power into the determination of real thermal resistance. In sequence, it was seen that the use of direct current reveals more accurate and reliable measurement results where the occurrence of electrical disturbance is minimized. 2013-07 Thesis http://eprints.usm.my/45102/ http://eprints.usm.my/45102/1/Lee%20Zhi%20Yin24.pdf application/pdf en public masters Universiti Sains Malaysia Pusat Pengajian Sains Fizik
institution	Universiti Sains Malaysia
collection	USM Institutional Repository
language	English
topic	QC1 Physics (General)
spellingShingle	QC1 Physics (General) Lee, Zhi Yin Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
description	The project signifies thermal and optical characterizations of pre-molded and ceramic package light emitting diodes (LEDs) that are conducted by using thermal transient and light emission recording techniques. It was observed that the luminous intensity of the LEDs is dependent on the input current. However, the LEDs efficiency is reduced for about 15% with the current increases, which due to the high current density and heating of LED junction. In terms of package-level and system-level, pre-molded package LED shows approximately to 13% and 15% lower in junction-to-case and junction-to-ambient thermal resistances respectively than ceramic package LED. Despite, the heat dissipation of ceramic package LED is improved after mounting on a metal-core board (board-level). Here, the effects of packaging material properties and ratio of contacting surface area are applied. Next, the results shows that the application of thermal compound as thermal interface material yields about 6% lower junction-to-ambient thermal resistance than thermal tape. Further investigation shows that the optimum heat convection for pre-molded package LED in an open-air environment is obtained as the cooling fan facing upward; while in terms of still-air environment, it is achieved as the cooling fan facing downward. Lastly, the accuracy of the captured thermal transient is improved by considering the optical power into the determination of real thermal resistance. In sequence, it was seen that the use of direct current reveals more accurate and reliable measurement results where the occurrence of electrical disturbance is minimized.
format	Thesis
qualification_level	Master's degree
author	Lee, Zhi Yin
author_facet	Lee, Zhi Yin
author_sort	Lee, Zhi Yin
title	Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
title_short	Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
title_full	Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
title_fullStr	Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
title_full_unstemmed	Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes
title_sort	comparison of thermal and optical behaviors of pre-molded and ceramic package light emitting diodes
granting_institution	Universiti Sains Malaysia
granting_department	Pusat Pengajian Sains Fizik
publishDate	2013
url	http://eprints.usm.my/45102/1/Lee%20Zhi%20Yin24.pdf
_version_	1747821455859515392

Comparison Of Thermal And Optical Behaviors Of Pre-Molded And Ceramic Package Light Emitting Diodes

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