New Packaging Technology For
White High-Power LEDs
1
Outlines
•
Introduction(3)
•
Paper review (13)
Paper 1
Study of Phosphor Thermal-Isolated Packaging Technologies for
High- Power White Light-Emitting Diodes (4)
Paper 2
Improved Performance White LED (6)
Paper 3
Analysis of high-power packages for phosphor-based white-lightemitting diodes (3)
•
Conclusion(1)
•
References(1)
2
Introduction
The destination of LED packaging：
－Packaging the Semiconductor chip can provide
electronic components of business using.
－To protect the chip against radiation, steam, oxygen
and the damage from the outside.
－Increase the authenticity of the components.
－Improve the functions of the chips.
－Provide the radiation organization for chips
－Design all kinds of packaging forms to provide
different applications of products.
3
Introduction
Die
attached
Molding
Epoxy
curing
Sorting
Singluration
Wire
bonding
Testing
4
Introduction
White light emitting diodes
RGB LED
Blue LED  YAG Phosphor
Blue LED  RG Phosphor
UV LED  RGB Phosphor
5
Study of Phosphor Thermal-Isolated
Packaging Technologies for High- Power White
Light-Emitting Diodes
Bingfeng Fan, Hao Wu, Yu Zhao, Yulun Xian, and Gang Wang
• Manuscript received February 12, 2007; revised April 17, 2007.
The authors are with State Key Laboratory of Optoelectronic
Materials and Technologies, Sun Yat-sen University, Guangzhou
5102, China, and also with
the School of Physics and Engineering, Sun Yat-sen University,
Guangzhou 51027755, China (e-mail: stswangg@mail.sysu.edu.cn).
Color versions of one or more of the figures in this letter are
available online at http://ieeexplore.ieee.org.
6
Experiment
Fig. Schematic cross-sectional view of (a) conventional phosphor
converting white LED and (b) thermal-isolated phosphor-converting
white LED, h = 1 mm.
7
Fig. Measured (red line, closed symbols) and simulated (blue line,
open symbols) temperature profile along the phosphor surface
midline in conventional packaging and thermal-isolated
packaging (both without placing lens).
8
• Luminous flux (left y-axis) and CCT (right y-axis) dependence of
input current for thermal-isolated white LED and conventional
white LED.
9
Improved Performance White LED
Nadarajah Narendran
•
•
•
Lighting Research Center Rensselaer Polytechnic Institute 21 Union
St. Troy, NY 12180 www.lrc.rpi.edu
Narendran, N. 2005. Improved performance white LED. Fifth
International Conference on Solid State Lighting, Proceedings of
SPIE 5941, 45-50. Bellingham, WA: International Society of Optical
Engineers.
Copyright 2005 Society of Photo-Optical Instrumentation Engineers.
This paper was published in the Fifth International Conference on
Solid State Lighting,
Proceedings of SPIE and is made available as an electronic preprint
with permission of SPIE. One print or electronic copy may be made
for personal use only. Systematic or multiple reproduction,
distribution to multiple locations via electronic or other means,
duplication of any material in this paper for a fee or for commercial
purposes, or modification of the content of the
paper are
prohibited.
10
• the 5 mm type phosphor-converted white LED
degraded faster than the blue LED. The main
difference between a blue and a similar white LED
is the phosphor that is dispersed within the epoxy
surrounding the die.
Figure : Schematic of
a 5 mm white LED.
Figure : Three LED arrays enclosed in an aluminum
cylinder.
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Three LED arrays enclosed in an aluminum
cylinder Results
Glass Window
with Phosphor coating
degraded slower than others.
Fig. Lumen depreciation data for the three LED arrays
at 40 mA.
12
Experiment
Figure : White LED using SPE concept.
＊
SPE stands for “Scattered Photon Extraction".
13
Results and discussion
• Comparison of traditional white LED efficacy with
SPE white LED efficacy as a function of current.
14
SUMMARY
• SPE has enabled higher luminous
efficacy with phosphor-converted white
LEDs. Unlike in traditional white LED
packages, in the SPE package the
phosphor layer is placed at a remote
location and the lens surrounding the die
is shaped to extract a significant portion
of the back-transferred light before it is
absorbed and lost within the package.
15
Analysis of high-power packages for phosphor-based
white-light-emitting diodes
Hong Luo
• Department of Physics, Applied Physics and Astronomy, Rensselaer
Polytechnic Institute, Troy,New York 12180
Jong Kyu Kim and E. Fred Schuberta!
Electrical, Computer, and Systems Engineering Department,
Rensselaer Polytechnic Institute, Troy,New York 12180
Jaehee Cho, Cheolsoo Sone, and Yongjo Park
Photonics Program Team, Samsung Advanced Institute of Technology,
Suwon 440-600, South Korea
(Received 23 February 2005; accepted 10 May 2005; published online
8 June 2005)
16
Experiment
• FIG. 1. Schematic cross-sectional view of the
dichromatic white LED lamps with (a) phosphor-in-cup
arrangement and (b) phosphor-on-top arrangement.
Three different geometries of the encapsulation dome,
flat (h=0), convex (h=r/2), and hemispherical (h=r).
17
Results and discussion
• Extraction efficiency of phosphorescence calculated by
ray tracing for different package configurations.
18
Conclusion
1.
The high-performance phosphor-converting white LEDs
with thermal-isolated phosphor coating layer. Compared
with the conventional LEDs, the new packaging showed a
much higher saturation point of output luminous flux and
provided an effective way to decrease the color variation.
2.
Using '‘thermal isolated packaging'' can reduce the effect
of heat on phosphor and prolong the life of LED.
3.
The character of light extraction was " Hemisphere >
Convex > Flat".
4.
For the description above, LED packaging can reach the
best stability once it uses thermal isolated and
Hemisphere packaging.
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References
1.
Bingfeng Fan, Hao Wu,Yu Zian,Yulun Xian, and Gang Wang “ Study of Phosphor ThermalIsolated Packaging Technologies for High- Power White Light-Emitting Diodes” IEEE
PHOTONICS TEHNOLOGY LETTERS, VOL, 19, NO. 15, AUGUST 1, 2007
2.
Narendran, N. “Improved performance white LED”. Fifth International
Conference on Solid State Lighting, Proceedings of SPIE 5941, 45-50. Bellingham,
WA: International Society of Optical Engineers. 2005
3.
Yutao Zhou, MEMBER SPIE Nadarajah Narendran, MEMBER SPIE Rensselaer
“Photovoltaic-powered light-emitting diode lighting systems” Optical
Engineering 4411, 111311 November 2005
4.
Hong Luo, Jong Kyu Kim and E. Fred Schubert “Analysis of high-power
packages for phosphor-based white-light-emitting diodes” APPLIED PHYSICS
LETTERS 86, 243505 (2005)
5.
Rafael C. Jordan, Jörg Bauer, and Hermann Oppermann ” Optimized heat
transfer and homogeneous color converting for Ultra High Brightness LED
Package Proc. Of SPIE Vol. 6198 61980B-1
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Thanks for your attention ！！
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