In last decade, white light emitting diodes(LEDs) have become used widely from traditional indicator to general illumination. The increase of its power is the key improving issue. The current light efficiency of white LED about 30%. In other words ,more than 70% of the input electrical energy will be generated in the form of heat. So, how to get rid of the heat damage in high power LED is a severe problem. The finite element analysis is employed to simulate high power white LEDs temperature distribution and thermal stress distributions caused by the dissipated heat.
The effects of package parameters, i.e. die attach, solder material, solder thickness, and chip substrate, on the temperature and thermal stress distributions on high power LED packages are simulated and studied in this thesis. A comparison between the 40mil single chip package and the chip on board(CoB) package has also been executed in this study. Simulated results indicate that the highest power of a single 40mil chip package is 7watt. The thermal stress distribution , i.e. the peak value of local thermal stress is over its yield strength, is occurred as the power up to 7watt. Numerical results also reveal that the appropriate fin design can improve the heat dissipation significantly in high power LED package.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0721111-120946 |
| Date | 21 July 2011 |
| Creators | Hou, Ling-Xuan |
| Contributors | Bo-Wun Huang, Ying-Chien Tsai, Yung-Chuan Chen, Der-Min Tsay, Jao-Hwa Kuang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0721111-120946 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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