scholarly journals Robust thermal performance of Sr2Si5N8:Eu2+: An efficient red emitting phosphor for light emitting diode based white lighting

2011 ◽  
Vol 99 (24) ◽  
pp. 241106 ◽  
Author(s):  
Stuart E. Brinkley ◽  
Nathan Pfaff ◽  
Kristin A. Denault ◽  
Zhijun Zhang ◽  
H. T. (Bert) Hintzen ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Red Emitting Phosphor

scholarly journals Thermal performance of heat sink with fluid pockets for high power light emitting diode

2017 ◽  
Vol 14 (4) ◽  
pp. 4846-4862
Author(s):  
Sangmesh ◽  
◽  
Gopalakrishna Keshava Narayana ◽  
Manjunath Shiraganhalli Honnaiah ◽  
Krishna Venkatesh ◽  
...  
Keyword(s):  
Thermal Performance ◽  
High Power ◽  
Heat Sink ◽  
Light Emitting Diode ◽  
Light Emitting

Thermal Performance of a Light Emitting Diode Light Engine for a Multipurpose Automotive Exterior Lighting System With Competing Board Technologies

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Umut Zeynep Uras ◽  
Mehmet Arık ◽  
Enes Tamdoğan
Keyword(s):  
Thermal Performance ◽  
Computational Models ◽  
Printed Circuit Boards ◽  
Light Emitting Diode ◽  
Ambient Conditions ◽  
Vapor Chamber ◽  
Metal Core ◽  
Light Emitting ◽  
Lighting Systems ◽  
Light Engine

In recent years, light emitting diodes (LEDs) have become an attractive technology for general and automotive illumination systems replacing old-fashioned incandescent and halogen systems. LEDs are preferable for automobile lighting applications due to its numerous advantages such as low power consumption and precise optical control. Although these solid state lighting (SSL) products offer unique advantages, thermal management is one of the main issues due to severe ambient conditions and compact volume. Conventionally, tightly packaged double-sided FR4-based printed circuit boards (PCBs) are utilized for both driver electronic components and LEDs. In fact, this approach will be a leading trend for advanced internet of things applications embedded LED systems in the near future. Therefore, automotive lighting systems are already facing with tight-packaging issues. To evaluate thermal issues, a hybrid study of experimental and computational models is developed to determine the local temperature distribution on both sides of a three-purpose automotive light engine for three different PCB approaches having different materials but the same geometry. Both results showed that FR4 PCB has a temperature gradient (TMaxBoard to TAmbient) of over 63 °C. Moreover, a number of local hotspots occurred over FR4 PCB due to low thermal conductivity. Later, a metal core PCB is investigated to abate local hot spots. A further study has been performed with an advanced heat spreader board based on vapor chamber technology. Results showed that a thermal enhancement of 7.4% and 25.8% over Al metal core and FR4-based boards with the advanced vapor chamber substrate is observed. In addition to superior thermal performance, a significant amount of lumen extraction in excess of 15% is measured, and a higher reliability rate is expected.

Performance of Hybrid Fin Heat Sinks for Thermal Control of Light Emitting Diode Lighting Modules

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Kyoung Joon Kim
Keyword(s):  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sink ◽  
Light Emitting Diode ◽  
Internal Flow ◽  
Thermal Control ◽  
Numerical Prediction ◽  
Light Emitting ◽  
Convection Condition ◽  
Pin Fins

In this paper we introduce a hybrid fin heat sink (HFH) proposed for the thermal control of light emitting diode (LED) lighting modules. The HFH consists of the array of hybrid fins which are hollow pin fins having internal channels and integrated with plate fins. The thermal performance of the HFH under either natural or forced convection condition is both experimentally and numerically investigated, and then its performance is compared with that of a pin fin heat sink (PFH). The observed maximum discrepancies of the numerical prediction to the measurement for the HFH are 7% and 6% for natural and forced convection conditions. The reasonable discrepancies demonstrate the tight correlation between the numerical prediction and the measurement. The thermal performance of the HFH is found to be 12–14% better than the PFH for the natural convection condition. The better performance might be explained by the enlarged external surface and the internal flow via the channel of the HF. The reference HFH is about 14% lighter than the reference PFH. The better thermal performance and the lighter weight of the HFH show the feasibility as the promising heat sink especially for the thermal control of LED street and flood lighting modules.

Thermal Performance Evaluation and Economic Analysis of LED Integrated with Thermoelectric Cooler Package

2011 ◽  
Vol 216 ◽  
pp. 106-110 ◽  
Author(s):  
Hong Qin ◽  
Da Liang Zhong ◽  
Chang Hong Wang
Keyword(s):  
Economic Analysis ◽  
Thermal Performance ◽  
Power Dissipation ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Vital Role ◽  
Junction Temperature ◽  
Total Power ◽  
Thermoelectric Cooler ◽  
Light Emitting

Thermal management is an important issue for light emitting diodes’ utilization. For high power light emitting diode (LED), active heat dissipation method plays a vital role. As a new cooling device, thermoelectric cooler (TEC) is applied in LED packaging for the precisely temperature controlled advantage. In order to evaluate the thermal performance of the TEC packaging designs in LED, experimental measurement is used to assess the chip’s junction temperature of three different cooling models, which include the heatsink model, the heatsink and fan model and the TEC, heatsink and fan model. Based on the research, it is better to apply TEC cooling methods with the power dissipation of LED less than 35 W and the wind speed is 3.6 m/s. However, the power dissipation of TEC itself plays a vital role of the total power dissipation of LED packaging. The results of economic analysis shows that the LED integrated with TEC package achieves 22.34% and 44.73% electric energy saving under the condition of 20 W and 30 W power dissipation of the LED chip contrasts to the fluorescent lamp, but sacrifices 2.71% electric power under the condition of 10 W power dissipation of the LED chip.

scholarly journals Thermal Performance of LED Filament in Flip-Chip Packaging Manufactured for Different Correlated Color Temperature

2021 ◽  
Vol 11 (19) ◽  
pp. 8844
Author(s):  
He Jiang ◽  
Jiming Sa ◽  
Cong Fan ◽  
Yiwen Zhou ◽  
Hanwen Gu ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Color Difference ◽  
Junction Temperature ◽  
Color Temperature ◽  
Constant Current ◽  
Light Emitting ◽  
Flip Chip Packaging

The effect of correlated color temperature (CCT) on the thermal performance of light emitting diode (LED) filament in flip-chip packaging was investigated in detail. Two filaments with different lengths were selected as the research object, and the thermal resistance of filaments under three CCT (2200 K, 2400 K, 2700 K) were studied. The optical properties and thermal parameters of the two groups of filaments were measured, and the results were analyzed combined with the color coordinate. The experimental results show that thermal properties of LED filaments is closely related to CCT. Under constant current condition, junction temperature decreases with the increase of color difference. With the change of phosphor glue and phosphorus powder ratio, the color temperature of LED filament also changes. In the filaments with the same chip structure and packaging mechanism, the higher the proportion of red phosphorescent powder, the worse the heat dissipation performance of the filament. These results show that in the design and manufacture of LED filament, it is helpful to control the CCT of LED filament under the premise of meeting the use requirements.

Thermal Performance of Domestic Replacement A19 LED Lighting Products

2016 ◽  
Author(s):  
Thomas Storey ◽  
Robin Rackerby ◽  
Heather Dillon ◽  
Lydia Gingerich
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Light Emitting Diode ◽  
Research Process ◽  
Light Emitting ◽  
Led Lighting ◽  
Proper Design ◽  
The Cost

In an effort to create a Light Emitting Diode (LED) lighting system that is as efficient as possible, the heat dissipation system must be accurately measured for proper design and operation. Because LED lighting technology is new, little optimization has been performed on typical cooling system required for most A19 replacement products. This paper describes the research process for evaluating the thermal performance of over 15 LED lighting products and compares their performance to traditional lighting sources, namely incandescent and compact fluorescent (CFL). This process uses radiation and convection to model typical cooling mechanisms for domestic A19 type replacement LED products. The A19 products selected for this investigation had input wattages ranging between 7 to 60 Watts, with outputs ranging from 450 to 1100 lumens. The average LED tested dissipated 43% (± 5%) of the total heat generated in the lighting product through the heat exchanger. The best thermal performance was observed in an LED product that dissipated approximately 58% of the total product heat through the heat exchanger. Results indicate that significant improvements to the current LED heat exchanger designs are possible, which will help lower the cost of future LED products, improve performance, and reduce the environmental footprint of the products.

Thermal Performance Prediction of a Finned Plain-Plate Heat-Pipe for LED Lamp

2011 ◽  
Vol 55-57 ◽  
pp. 2135-2138
Author(s):  
Xu Liang Xie
Keyword(s):  
Thermal Conductivity ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Performance Prediction ◽  
Heat Transfer Performance ◽  
Light Emitting Diode ◽  
Cooling Capacity ◽  
Light Emitting ◽  
Plate Heat ◽  
Inclined Angle

In order to keep the temperature of Light emitting diode (LED) lamp below some limitation, a finned plain-plate heat-pipe was presented and numerically investigated to predict heat transfer performance under natural convection. Two kinds of fin configurations were studied. It is found that 30° is the worst orientation for the fin configuration with the tops of every other two channels covered, while the worst orientation is around 60° for the fin configuration with channel tops opened. The thermal conductivity of fin material only has mild effect on the cooling capacity with 7 % difference when its thermal conductivity varies from 50 to 200 W/(m·k). The latter configuration has better thermal performance than the former at the same orientation, especially at relatively low inclined angle.

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