scholarly journals Enhanced Heat Dissipation Performance of Automotive LED Lamps Using Graphene Coatings

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 50
Author(s):  
Tun-Ping Teng ◽  
Wei-Jen Chen ◽  
Chun-Hsin Chang
Keyword(s):  
Minimum Temperature ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Beam Irradiation ◽  
Cooling Performance ◽  
Light Emitting ◽  
High Beam ◽  
Ambient Temperatures ◽  
Baseline Case ◽  
Irradiation Angle

Graphene heat-dissipating coating (GNHC) of 0.6 wt % GN concentration is utilized to promote the cooling performance of automotive light-emitting diode (LED) lamps. Three cases are studied as follows: Case 0 is the original automotive LED lamp as the baseline. Case 1 is to apply GNHC to reduce the thermal resistance of the junction surfaces between the components of automotive LED lamps. The aluminum fin radiator of Case 1 is further coated with GNHC on the surface that becomes Case 2. The spectrum, illuminance, power consumption, and surface temperature are measured at different ambient temperatures (Ta) to fully evaluate the feasibility of applying GNHC to improve cooling performance and the impacts on the related characteristics of automotive LED lamps. The results show that the maximum illuminance efficacy of Case 1 and Case 2 with high beam, irradiation angle of 0 degrees, and Ta of 80 °C is 11.03% and 8.70% higher than that of Case 0, respectively. The minimum temperature difference of heat dissipation path of Case 1 and Case 2 with high beam, irradiation angle of 90 degrees, and Ta of 80 °C is 6.41% and 5.33% lower than that of Case 0, respectively, indicating GNHC as a promising coating material for improving the cooling performance of automotive LED lamps.

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.

Thermal Analysis of High Power Light Emitting Diodes Package

2011 ◽  
Vol 687 ◽  
pp. 215-221
Author(s):  
Yuan Yuan Han ◽  
Hong Guo ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ke Chu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
High Power ◽  
Thermal Field ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Convective Heat Exchange ◽  
Input Power ◽  
Junction Temperature ◽  
Original Structure ◽  
Light Emitting

With increasing of the input power of the chips in light emitting diode (LED)， the thermal accumulation of LEDs package increases. Therefore solving the heat issue has become a precondition of high power LED application. In this paper, finite element method was used to analyze the thermal field of high power LEDs. The effect of the heatsink structure on the junction temperature was also investigated. The results show that the temperature of the chip is 95.8°C which is the highest, and it meets the requirement. The conductivity of each component affects the thermal resistance. Convective heat exchange is connected with the heat dissipation area. In the original structure of LEDs package the heat convected through the substrate is the highest, accounting for 92.58%. Three heatsinks with fin structure are designed to decrease the junction temperature of the LEDs package.

Anti-Glare Device for Car Based on Single Chip Microcomputer

2013 ◽  
Vol 706-708 ◽  
pp. 1124-1127
Author(s):  
Hai Xia Li
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Lamp Method ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Light Emitting ◽  
High Beam ◽  
The Core

Because the car headlamp light intensity is too large and it leads to accidents, This paper is based on the initiative to reduce the light intensity of their vehicles according headlights glare or close the high beam and open the lamp method, to achieve the purpose of the glare. The system is AT89C51 microcontroller as the core control, use of photodiode sensor to induction opposite the car headlights light intensity , when opposite car headlights light intensity up to a certain value, photodiode get a signal to the microcontroller ,and then microcontroller sends a signal, to control buzzer sound or not. When the buzzer sounded, using DAC0832 chip to control the brightness of the light emitting diode or control the light on and off and low beam enabled. When enabled for dipped beam, has been more than the antiglare range; after the scope enabled high beam, in order to achieve the anti-dazzle cycle. Through practice, the system has reached the anti-dazzle purpose and has practical value .

Improved Heat Dissipation in GaN-Based Thin-Film Light-Emitting Diode with Lateral-Electrode Configuration

2015 ◽  
Vol 7 (2) ◽  
pp. 283-286
Author(s):  
Jiang-Yong Zhang ◽  
Lei-Ying Ying ◽  
Ming Chen ◽  
Wen-Jie Liu ◽  
Jian Yu ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Electrode Configuration ◽  
Light Emitting

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.

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