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Recent Patents on Signal Processing
ISSN (Print): 2210-6863
ISSN (Online): 1877-6124
VOLUME: 3
ISSUE: 1
DOI: 10.2174/2210686311303010007









A Dual Side Electroluminescence Measurement System for LED Wafer Manufacturing

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Author(s): H.- T. Kim, J. Kim, S. Kim, H.- K. Yuh, D.- H. Kim, D.- H. Ahn and D.- S. Shin
Pages 49-55 (7)
Abstract:
A measurement system is presented for evaluating the characteristics of both sides of an LED wafer using electroluminescence (EL). Integrating spheres (IS), photodiodes, pico-ammeters, spectrometers were installed in the front and rear sides to measure optical characteristics with minimum EL loss. A probe was connected to a source meter with a thin wire and attached using a transparent fixture in the front IS. The EL characteristics in a measuring point were peak wavelength, FWHM (full width at half maximum), forward current, forward voltage and reverse current. EL images were created by combining the motion of a stage and the EL characteristics. The correlation between the EL and the chip-level tests and the repeatability test showed that the dual measurement is useful for LED manufacturing. Our patents were applied to install the probe and create the EL image.
Keywords:
Electroluminescence, EL imaging, epi-wafer, Optical spectrum, LED manufacturing.
Affiliation:
Smart System Research Group, KITECH, 35-3, HongCheon, IpJang, CheonAn, ChungNam 331-825, Korea.