Journal of the Korean Society of Manufacturing Technology Engineers (한국생산제조학회지)

The Korean Society of Manufacturing Technology Engineers (한국생산제조학회)
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Fine Dispensing Process of High Viscosity Phosphor for Repairing Application of White LED

백색 LED 보정 공정 적용을 위한 고점도 형광체 미세 정량토출 공정

  • Yang, Bong Su (Dept. of Electronic Engineering, Jeju Nat'l University) ;
  • Yang, Young Jin (Dept. of Mechatronics Engineering, Jeju Nat'l University) ;
  • Kim, Hyung Chan (Jeju Division, Korea Institute of Industrial Technology) ;
  • Ko, Jeong Beom (Jeju Division, Korea Institute of Industrial Technology) ;
  • Cho, Kyung Ho (Dept. of Mechatronics Engineering, Jeju Nat'l University) ;
  • Doh, Yang Hoi (Dept. of Electronic Engineering, Jeju Nat'l University)
  • Received : 2015.12.28
  • Accepted : 2016.04.06
  • Published : 2016.04.15
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Abstract

Several research works for finding and optimizing the methods of dispensing high viscosity phosphor used in the fabrication of white LED's are currently in progress. High viscosity phosphor dispensing with a high accuracy is crucial because the dispensing rate and uniformity directly affect parameters such as the CIE chromaticity diagram, color temperature and luminous flux of white LED's. This study presents a novel method of dispensing high viscosity phosphor using electrohydrodynamic printing. The dispensing rate was optimized less than 0.01 mg phosphor using experiments and optimizing the process parameters including the standoff distance from the nozzle to the substrate, ink supply pressure, and multi-step pulsed waveform magnitude ratio. The dispensing rate was measured by dispensing 20 dots using drop-on-demand with the optimized parameters, and the experiments were repeated 10 times to maximize the data accuracy. The average dispensing rate that can be reliably used for high viscosity phosphor dispensing was 0.0052 mg.

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References

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