A Simple Package Technique of Light Emitting Diode for Enhancing Illuminant Quality

by Lin, Yu-Chung

Abstract (Summary)
The purpose of this thesis is to fabricate an LED module with low half intensity angle(HIA) ,and to use this module to form a line source with optical performance comparable to that of a CCFL .In addition ,heat dissipation of the LED module on different sub-mounts is also investigated . The LED modules were formed by first etching a through si via on silicon substrate using wet etching technology for light confining .Then a thin layer of metal was deposited on to the via to reflect the lights emitted from the LED .The LED die was attached to the Si sub-mount with electrodes ,and the connections between the LED and the Si sub-mount were completed by wire bonding .Finally ,the LED modules were obtained by positioning the Si substrates onto the Si sub-mounts using UV epoxy . The optical performance of the LED module was simulated by Lighttools .For the si substrate with a thickness of 400 £gm ,a simulated HIA of 36 o was obtained .Using six-LED package ,a 3-cm line source with 84.8% output uniformity was simulated .On the other hand ,the measured HIA of a LED module ,and the uniformity of 3-cm line source are 38 o and 84.8% ,respectively. The thermal resistance of the si sub-mounts were also investigated .The different structures of the sub-mount were proposed ,namely ,LED to Copper case ,LED to Si sub-mount to Copper case ,and LED to Si sub-mount with Copper filled via to Copper case .The estimated thermal resistance of the sub-mounts are 13 W/mk¡B19.4 W/mk and 34.7 W/mk .We believe that the large thermal resistance of the Si sub-mount with Copper filled via is primarily caused by 800 £gm thick substrate .
Bibliographical Information:

Advisor:Mei-Ying CHang; Yi-Jen Chiu; Ting-Chang Chang; Ann-Kuo Chu

School:National Sun Yat-Sen University

School Location:China - Taiwan

Source Type:Master's Thesis

Keywords:package light emitting diode led


Date of Publication:06/20/2008

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