New Packaging Technology For White High-Power LEDs

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• • • •

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-light emitting diodes (3) Conclusion (1) References (1)

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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.

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Introduction

Die attached Molding Epoxy curing Singluration Wire bonding Testing Sorting

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Introduction

White light emitting diodes RGB LED Blue LED



RG Phosphor Blue LED



YAG Phosphor UV LED



RGB Phosphor

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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: [email protected]).

Color versions of one or more of the figures in this letter are available online at http://ieeexplore.ieee.org.

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Experiment

Fig. Schematic cross-sectional view of (a) conventional phosphor converting white LED and (b) thermal-isolated phosphor-converting white LED, h = 1 mm.

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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).

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• Luminous flux (left y-axis) and CCT (right y-axis) dependence of input current for thermal-isolated white LED and conventional white LED.

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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.

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• 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 : Three LED arrays enclosed in an aluminum cylinder.

Figure : Schematic of a 5 mm white LED

.

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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.

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Experiment

＊

Figure :

White LED using SPE concept.

SPE stands for “Scattered Photon Extraction".

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Results and discussion

• Comparison of traditional white LED efficacy with SPE white LED efficacy as a function of current.

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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.

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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).

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Results and discussion

• Extraction efficiency of phosphorescence calculated by ray tracing for different package configurations.

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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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1.

2.

References

Bingfeng Fan, Hao Wu,Yu Zian,Yulun Xian, and Gang Wang “ Study of Phosphor Thermal Isolated Packaging Technologies for High- Power White Light Emitting Diodes” IEEE PHOTONICS TEHNOLOGY LETTERS, VOL, 19, NO. 15, AUGUST 1, 2007 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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