DOI QR코드

DOI QR Code

백색 LED 보정 공정 적용을 위한 고점도 형광체 미세 정량토출 공정

Fine Dispensing Process of High Viscosity Phosphor for Repairing Application of White LED

  • 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)
  • 투고 : 2015.12.28
  • 심사 : 2016.04.06
  • 발행 : 2016.04.15

초록

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.

키워드

참고문헌

  1. Park, S. C., 2012, Luminous Efficiency of Phosphor-converted White Light Emitting Diodes, A Thesis for a Doctorate, Kyungpook National University, Republic of Korea.
  2. Ha, S. J., Kim, J. S., Cho, M. W., Choi, J. M., 2013, Measurement System for Phosphor Dispensing Shape of LED Chip Package Using Machine Vision, J. Korea Academia-industrial Cooperation Soc., 14:5 2113-2120. https://doi.org/10.5762/KAIS.2013.14.5.2113
  3. Kim, S. H., 2011, Screw Pump for Dispensing LED Phosphor Wear Characteristic, A Thesis for a Master, Inha University, Republic of Korea.
  4. Kang, D. S., 2015, A Study on the CIE Rank Positioning Method for using Electrohydrodynamic Micro-dispensing Mechanism, A Thesis for a Master, Inha University, Republic of Korea.
  5. Jaworek, A., Krupa, A., 1999, Classification of the Modes of EHD Spraying, J. Aerosol Sci., 30:7 873-893. https://doi.org/10.1016/S0021-8502(98)00787-3
  6. Kang, D. K., 2011, Experimental Study on Solar Cell Electrode Via Electrohydrodynamic(EHD) Inkjet Printing, A Thesis for a Master, Korea University, Republic of Korea.
  7. Rahman, A., Ali, A., Rahman, K., Kim, H. C., Doh, Y. H., Kim, D. S., Choi, K. H., 1999, Influence of Electrode Position and Electrostatic Forces on the Generation of Meniscus in Dielectric Ink, Japanese journal of applied physics, 49:5 05EC02-(1-8). https://doi.org/10.1143/JJAP.49.05EC02
  8. Ko, J. B., 2011, Research on Electrostatic Based High Aspect Ration Microelectrode Patterning Process, A Thesis for a Doctorate, Jeju National University, Republic of Korea.
  9. Smith, D. P. H., 1986, The Eelctrohydrodynamic Atomization of Liquids, IEEE Transactions on Industry Applications, IA-22:3 527-535. https://doi.org/10.1109/TIA.1986.4504754
  10. Taylor, G., 1964, Disintegration of Water Drops in an Electric Field, Proc. Roy. Soc. A, 280:1382 383-397. https://doi.org/10.1098/rspa.1964.0151
  11. Gana-Calvo, A. M., 1997, Cone-jet Analytical Extension of Taylor's Electrostatic Solution and the Asymptotic Universal Scaling Laws in Electrospraying, Phys. Rev. Lett., 29:2 217-220.
  12. Yang, Y. J., Kim, H. C., Ko, J. B., Yang, B. S., Dang, H. W., Doh, Y. H., Cho, K. H., Choi, K. H., 2014, A Study on High Visocisy Phosphor Dispensing Process for Implementation of High-Efficiency White LED, J. Clean Tech., 20:2 97-102. https://doi.org/10.7464/ksct.2014.20.2.097
  13. Yang, Y. J., Ko, J. B., Dang, H. W. Kim, H. C., Choi, K. H., Cho, K. H., 2012, Development of Pneumatic Ink Supply System for Electrostatic head on Meniscus control, J. KSPE, 29:4 455-460. https://doi.org/10.7736/KSPE.2012.29.4.455
  14. Kim, S. W., Yang, Y. J., Kim, H. B., Dang, H. W., Yang, B. S., Choi, K. H., 2015, A Study of High Visocisy Phosphor Dispensing for an Electrostatic Printing Sytem, Trans. Mat. Proc., 24:2 83-88. https://doi.org/10.5228/KSTP.2015.24.2.83