Characterization of High-Power COB LED Module Attached by Low-Temperature Sintered Nanosilver

2016 ◽  
Vol 853 ◽  
pp. 389-393 ◽  
Author(s):  
Jia Chen ◽  
Xin Li ◽  
Ya Fei Kong
Keyword(s):  
High Power ◽  
Junction Temperature ◽  
Power Module ◽  
High Brightness ◽  
Ambient Temperatures ◽  
Die Attach ◽  
High Power Led ◽  
Increasing Demand ◽  
Nanosilver Paste

Along with the increasing demand of high power LED (>1W), multi-chip modules have made great progress to an inevitable trend. Thus, large packaging area is needed to dissipate heat efficiently. In other words, only when we find appropriate packaging materials to control the junction temperature well, can we achieve high-power LED devices in smaller packaging area. Obviously, a die-attach layer as the first-level packaging has a most significant impact on the thermal performance of a power module. So we introduce a novel die-attach material, nanosilver paste, which can be used for connecting multi-chips on the substrate because of its higher melting temperature and better thermal/electrical conductivity than conventional solders and adhesive films. What is more important, because of their ability to emit high brightness, LED packages are being exploited for other systems or fields, and in most cases are exposed to harsher environments. Therefore, the performance and stability of LED packages will be the key to assuring the reliable function of systems. So, in this paper, the optical and electrical properties of the LED device operating under various ambient temperatures from 27 to 120°C were determined. The test results showed that nanosilver paste was a very promising die-attach material in high power multi-chip modules packaging.

Improved Heat Dissipation and Optical Performance of High-power LED Packaging with Sintered Nanosilver Die-attach Material

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 001585-001605 ◽  
Author(s):  
Paul Panaccione ◽  
Tao Wang ◽  
Guo-Quan Lu ◽  
Xu Chen ◽  
Susan Luo
Keyword(s):  
Thermal Resistance ◽  
High Power ◽  
Heat Removal ◽  
High Current ◽  
Die Attach ◽  
High Power Led ◽  
Silver Epoxy ◽  
The Difference ◽  
Nanosilver Paste ◽  
The Impact

Heat removal in packaged high-power light-emitting diode (LED) chips is critical to device performance and reliability. Thermal performance of LEDs is important in that lowered junction temperatures extend the LED's lifetime at a given photometric flux (brightness). Optionally, lower thermal resistance can enable increased brightness operation without exceeding the maximum allowable Tj for a given lifetime. A significant portion of the junction-to-case thermal resistance comes from the joint between chip and substrate, or the die-attach layer. In this study, we evaluated three different types of leading die-attach materials; silver epoxy, lead-free solder, and an emerging nanosilver paste. Each of the three was processed via their respective physical and chemical mechanisms: epoxy curing by cross-linking of polymer molecules; intermetalic soldering by reflow and solidification; and nanosilver sintering by solid-state atomic diffusion. High-power LED chips with a chip area of 3.9 mm2 were attached by the three types of materials onto metalized aluminum nitride substrates, wire-bonded, and then tested in an electro-optical setup. The junction-to-heatsink thermal resistance of each LED assembly was determined by the wavelength shift methodology, described in detail in this paper. We found that the average thermal resistance in the chips attached by the nanosilver paste was the lowest, and it is the highest from the chips attached by the silver epoxy: the difference between the two was about 0.7°C/W, while the difference between the sintered and soldered was about 0.3°C/W. The lower thermal resistance in the sintered joints is expected to significantly improve the photometric flux from the device. Simple calculations, excluding high current efficiency droop, predict that the brightness improvement could be as high as 50% for the 3.9 mm2 chip. The samples will be functionally tested at high current, in both steady-state and pulsed operation, to determine brightness improvements, including the impact of droop. Nanosilver die-attach on a range of chip sizes up to 12 mm2 are also considered and discussed.

Improved Heat Dissipation and Optical Performance of High-Power LED Packaging with Sintered Nanosilver Die-Attach Material

2010 ◽  
Vol 7 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Paul Panaccione ◽  
Tao Wang ◽  
Xu Chen ◽  
Susan Luo ◽  
Guo-Quan Lu
Keyword(s):  
Thermal Resistance ◽  
High Power ◽  
Heat Removal ◽  
High Current ◽  
Die Attach ◽  
High Power Led ◽  
Silver Epoxy ◽  
The Difference ◽  
Nanosilver Paste ◽  
The Impact

Heat removal in packaged high-power light-emitting diode (LED) chips is critical to device performance and reliability. Thermal performance of LEDs is important in that lowered junction temperatures extend the LED's lifetime at a given pho-tometric flux (brightness). Optionally, lower thermal resistance can enable increased brightness operation without exceeding the maximum allowable Tj for a given lifetime. A significant portion of the junction-to-case thermal resistance comes from the joint between chip and substrate, or the die-attach layer. In this study, we evaluated three different types of leading die-attach materials; silver epoxy, lead-free solder, and an emerging nanosilver paste. Each of the three was processed via their respective physical and chemical mechanisms: epoxy curing by cross-linking of polymer molecules; intermetalic soldering by reflow and solidification; and nanosilver sintering by solid-state atomic diffusion. High-power LED chips with a range of chip areas from 3.9 mm2 to 9.0 mm2 were attached by the three types of materials onto metalized aluminum nitride substrates, wire-bonded, and then tested in an electro-optical setup. The junction-to-heatsink thermal resistance of each LED assembly was determined by the wavelength shift methodology. We found that the average thermal resistance in the chips attached by the nanosilver paste was the lowest, and it was highest from the chips attached by the silver epoxy. For the 3.9 mm2 die, the difference was about 0.6°C/W, while the difference between the sintered and soldered was about 0.3°C/W. The lower thermal resistance in the sintered joints is expected to significantly improve the photometric flux from the device. Simple calculations, excluding high current efficiency droop, predict that the brightness improvement could be as high as 50% for the 3.9 mm2 chip. The samples will be functionally tested at high current, in both steady-state and pulsed operation, to determine brightness improvements, including the impact of droop. Nanosilver die-attach on a range of chip sizes up to 12 mm2 are also considered and discussed.

Reliability of High-Power Light Emitting Diode Attached With Different Thermal Interface Materials

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Xin Li ◽  
Xu Chen ◽  
Guo-Quan Lu
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Temperature Cycling ◽  
Fluorescent Light ◽  
Light Sources ◽  
Light Emitting ◽  
Die Attach ◽  
Nanosilver Paste ◽  
Interconnection Material

As a solid electroluminescent source, white light emitting diode (LED) has entered a practical stage and become an alternative to replace incandescent and fluorescent light sources. However, due to the increasing integration and miniaturization of LED chips, heat flux inside the chip is also increasing, which puts the packaging into the position to meet higher requirements of heat dissipation. In this study, a new interconnection material—nanosilver paste is used for the LED chip packaging to pursue a better optical performance, since high thermal conductivity of this material can help improve the efficiency of heat dissipation for the LED chip. The bonding ability of this new die-attach material is evaluated by their bonding strength. Moreover, high-power LED modules connected with nanosilver paste, Sn3Ag0.5Cu solder, and silver epoxy are aged under hygrothermal aging and temperature cycling tests. The performances of these LED modules are tested at different aging time. The results show that LED modules sintered with nanosilver paste have the best performance and stability.

Evaluation of Test Protocol for Eutectic Die Attach Using High Power LEDs

2011 ◽  
Vol 2011 (1) ◽  
pp. 000136-000141 ◽  
Author(s):  
Amanda Hartnett ◽  
Seth Homer ◽  
Donald Beck ◽  
Daniel Evans
Keyword(s):  
High Power ◽  
Coefficient Of Thermal Expansion ◽  
Test Methods ◽  
Test Protocol ◽  
High Brightness ◽  
Light Emitting ◽  
Power Semiconductor ◽  
Heat System ◽  
Die Attach ◽  
Manufactured Products

High-power semiconductor devices, such as high-brightness Light Emitting Diodes (LEDs), must be mounted using a robust adhesive material to handle the temperature fluctuations generated by the chip and the mechanical stresses due to the coefficient of thermal expansion (CTE) mismatches between the die material and substrate it is mounted to. The selected material must also comply with current legislation restricting manufactured products containing numerous materials including some that were historically popular in HB LED applications due to environmental concerns. Eutectic gold-tin (AuSn) materials meet these requirements, and process recommendations for their implementation will be presented in this paper. Utilizing a Palomar Technologies die bonder, AuSn solder preforms and paste will be placed/dispensed and reflowed using a Pulsed Heat System (PHS). Evaluation methods comparing these means of eutectic die attach to a pre-plated AuSn die will be discussed. Technical generalizations will be detailed to explain the derivation of test methods as well as hypotheses of results.

High Temperature Reliability of High-power LED Module Using Die Attach Material of Nano-silver Paste

2016 ◽  
Vol 37 (9) ◽  
pp. 1159-1165
Author(s):  
陈佳 CHEN Jia ◽  
李欣 LI Xin ◽  
孔亚飞 KONG Ya-fei ◽  
梅云辉 MEI Yun-hui ◽  
陆国权 LU Guo-quan
Keyword(s):  
High Temperature ◽  
High Power ◽  
Silver Paste ◽  
Nano Silver ◽  
Die Attach ◽  
High Power Led

The Accelerated Aging Characterization of High Power LED

2012 ◽  
Vol 33 (11) ◽  
pp. 1236-1240 ◽  
Author(s):  
李艳菲 LI Yan-fei ◽  
张方辉 ZHANG Fang-hui ◽  
张静 ZHANG Jing
Keyword(s):  
High Power ◽  
Accelerated Aging ◽  
High Power Led

Heat Dissipation Simulation Analysis of High Power LED via Heat Slug Geometry Variation

2014 ◽  
Vol 1082 ◽  
pp. 344-347
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Rajendaran Vairavan ◽  
Hussin Kamarudin ◽  
Mukhzeer Mohamad Shahimin ◽  
...  
Keyword(s):  
High Power ◽  
Heat Dissipation ◽  
Simulation Analysis ◽  
Life Time ◽  
Junction Temperature ◽  
Von Mises Stress ◽  
Potential Development ◽  
High Power Led ◽  
Superior Surface ◽  
Von Mises

High power LEDs are currently being plagued by heat dissipation challenges due to its high power density thus limiting its further potential development and fulfillment. Exercising proper selection of packaging component could improve the life time of high power LED. In this work, the significance of the heat slug geometry on the heat dissipation of high power LED was addressed through simulation analysis. The heat slug geometries were varied in order to compare the heat dissipation of the high power LED. Ansys version 11 was utilized for the simulation. The heat dissipation of the high power LED was evaluated in terms of junction temperature, von Mises stress and thermal resistance. The key results of the analysis showed that a superior surface area is preferred for an enhanced heat dissipation of high power LED

High Power LED Integrated With Silicon-Based Thermoelectric Cooler Package

2007 ◽  
Author(s):  
Ming-Ji Dai ◽  
Chih-Kuang Yu ◽  
Chun Kai Liu ◽  
Sheng-Liang Kuo
Keyword(s):  
High Power ◽  
Flip Chip ◽  
Light Emitting Diode ◽  
Infrared Camera ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Thermoelectric Cooler ◽  
High Power Led ◽  
Silicon Based ◽  
Light Efficiency

A new thermal management application of silicon-based thermoelectric (TE) cooler integrated with high power light emitting diode (LED) is investigated in present study. The silicon-based TE cooler herein is fabricated by MEMS fabrication technology and flip-chip assembly process that is used for high power LED cooling. An electrical-thermal conversion method is used to estimate the junction temperature of LED. Moreover, the Integrating Sphere is also used to measure the light efficiency of LED. The thermal images photographed by infrared camera demonstrated the cooling function of the silicon-based TE devices. The results also show that high power LED integrated with silicon-based thermoelectric cooler package can effectively reduce the thermal resistance to zero. In addition, the light efficiency of the LED (1W) will increase under low TE cooler input power (0.55W), which is about 1.3 times of that without TE cooler packaging.

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