| Summary: | 碩士 === 國立中興大學 === 精密工程學系所 === 95 === In this thesis, the properties of lamp packaged from the light emitting diodes (LEDs) grown by epitaxial lateral overgrowth (ELOG) and Si treatment were compared. Here, these LEDs (before packaged) present almost the same luminous intensity. Then, these two kind lamps will be tested in ESD ability and life test under different temperature and current to compare the difference of various characteristics between the lamps.
The luminous intensity of ELOG LED and LED with Si treatment after packaged was about 5.46 cd and 3.31 cd, respectively. The corresponding output powers of these two kind LEDs after package was 15.43 mW and 15.18 mW. The difference was not obvious. Nevertheless, the luminous intensity of LED with Si treatment can not reach the level of ELOG LED because the distribution of optical field and spindle light closed to p electrode. The current distribution of LED with Si treatment was not very well so it causes the lower forward ESD ability. ELOG LED presents better reverse ESD ability than LED with Si treatment does. It could be attributed to the dislocations reducing the ESD ability. In the common condition : 85˚C, 55%RH, 20mA, the light decay of ELOG LED was less 11.80% than that of LED with Si treatment. LED with Si treatment has second p-GaN epilayer which can resist the metal diffusion into epilayer by electromigration so it has lower leakage current.
According to the various tests in this thesis, the mechanisms about the difference of luminous intensity, the quality of ESD ability and the decay of life test were provided for these two kinds of LEDs after packaged. The database of customer complain analysis system and reliability quality system were also established.
keyword：GaN, luminous intensity, ESD, life test
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