scholarly journals Optimization of fins arrangements for the square light emitting diode (LED) cooling through nanofluid-filled microchannel

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammad Hatami
Keyword(s):  
Heat Transfer ◽  
Light Emitting Diode ◽  
Convection Heat Transfer ◽  
Micro Channel ◽  
Cooling Process ◽  
Cooling Fluid ◽  
Light Emitting ◽  
Heat Transfer Efficiency ◽  
Die Attach ◽  
Flow Through

AbstractIn current paper, a finned micro-channel is designed for the cooling application in Light Emitting Diode (LED), numerically using Galerkin weighted residual Finite Element Method (GFEM). Selected materials for LED-chip is GaN, Die from Si, Die-attach is made by Au-20Sn, substrate is copper and heat sink material is considered to be Al. To make a convection heat transfer for cooling process, Al2O3-water nanofluid is used as the cooling fluid flow through the micro-channel and tried to maximize the heat transfer efficiency by optimized geometry. For this aim, there geometry variables from the microchannel were selected and minimum possible geometry cases (11 cases) were proposed by Central composite design (CCD) and variables were optimized by the Response Surface Method (RSM). As a main result, parameter B, i.e. fin length had the most effect on the Nusselt number and Al2O3 nanoparticles with φ = 0.05 stated greatest heat transfer value. Also, different designs of fins arrangements, caused up to 6.5% increase in the nanofluid temperature which enhanced the LED cooling process.

scholarly journals Optimization of Fins Arrangements for the Square Light Edding Diode (LED) Cooling through Nanofluid-Filled Microchannel

2021 ◽  
Author(s):  
Mohamed Bechir Ben Hamida ◽  
Mohammad Hatami
Keyword(s):  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Micro Channel ◽  
Cooling Fluid ◽  
Heat Transfer Efficiency ◽  
Surface Method ◽  
Die Attach ◽  
Flow Through ◽  
Central Composite ◽  
Fin Length

Abstract In current paper, a finned micro-channel is designed for the cooling application in Light Edding Diode (LED), numerically. Selected materials for LED-chip is GaN, Die from Si, Die-attach is made by Au-20Sn, substrate is copper and heat sink material is considered to be Al. To make a convection heat transfer for cooling process, Al2O3-water nanofluid is used as the cooling fluid flow through the micro-channel and tried to maximize the heat transfer efficiency by optimized geometry. For this aim, there geometry variables from the microchannel were selected and minimum possible geometry cases (11cases) were proposed by Central composite design (CCD) and variables were optimized by the Response Surface Method (RSM). As a main result, parameter B, i.e. fin length had the most effect on the Nusselt number and Al2O3 nanoparticles with φ = 0.01 stated greatest heat transfer value.

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.

Automated Precision Assembly for High-Volume HB LEDs

2011 ◽  
Vol 2011 (1) ◽  
pp. 000117-000122
Author(s):  
Donald J. Beck ◽  
Jessica Sylvester
Keyword(s):  
Light Emitting Diode ◽  
High Reliability ◽  
Bright Light ◽  
High Volume ◽  
Commercial Production ◽  
Production Lines ◽  
Light Emitting ◽  
Die Attach ◽  
High Volume Production ◽  
Volume Production

Since the introduction of automated die and wire bonders in the 1980s, equipment manufacturers and process engineers have been challenged to balance speed with repeatability. Today, die bonders can perform epoxy die attach at a rate of 1.5 to 4 thousand die per hour [6]; and wire bonders can interconnect complex packages at speeds of more than 10 wires per second [7]. The advantage of automation is speed and consistency—however, there is one major concern with operating at these speeds: if something in the assembly process is wrong, everything will be wrong. Having tightly regulated assembly processes helps avoid the risk of building a large batch of rejected product. This paper presents a methodology and process flow supporting High Bright Light Emitting Diode (HB LED) automated assembly, supported by equipment certification, product inspection and SPC data collection methods. The methods presented in this paper have been formulated through extensive work in the high-reliability microelectronics industry and commercial production lines over the last three decades. To ensure time-to-market success in high-volume production, specific methods to achieve throughput and quality are required. This paper will cover the strategies and methods necessary to achieve the ultimate goal of an automated precision HB LED assembly—to blend the requirements of high-reliability and high-throughput to support high-volume commercial production.

Numerical Analysis for Thermal Performance of High Power Multi-Chip LED Packaging

2010 ◽  
Vol 139-141 ◽  
pp. 1433-1437
Author(s):  
Kai Lin Pan ◽  
Jiao Pin Wang ◽  
Jing Liu ◽  
Guo Tao Ren
Keyword(s):  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Light Emitting ◽  
Die Attach ◽  
Dissipation Model ◽  
Key Issues

Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.

Bio-Inspired Segmented Flow: Effect of Particle Elongation on the Heat Transfer

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Laura Small ◽  
Fatemeh Hassanipour
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Exchange Process ◽  
Convection Heat Transfer ◽  
Spherical Geometry ◽  
Spherical Particles ◽  
Channel Height ◽  
Segmented Flow ◽  
Heat Transfer Efficiency ◽  
Shaped Particle

This study presents numerical simulations of forced convection heat transfer with parachute-shaped segmented flow. The particles are encapsulated phase-change material flowing with water through a square cross-section duct with iso-flux boundaries. The system is inspired by the gas exchange process in the alveolar capillaries between red blood cells and lung tissue. A numerical model is developed for the motion of elongated encapsulated phase-change particles along a channel in a particulate flow where particle diameters are comparable with the channel height. The heat transfer enhancement for the parachute-shaped particles is compared with that of the spherical particles. Results reveal that the snug movement of the particles has the key role in heat transfer efficiency. The parachute-shaped geometry produces small changes in the heat transfer coefficient compared to a spherical geometry. However, the parachute-shaped particle flow is more robust to changes in particle concentration inside the channel.

Numerical Simulation of Turbulent Heat Transfer on a Rotating Disk With an Impinging Jet

2010 ◽  
Author(s):  
M. H. Saidi ◽  
H. Karrabi ◽  
H. B. Avval ◽  
A. Asgarshamsi
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Rotating Disk ◽  
Turbulent Heat Transfer ◽  
Maximum Temperature ◽  
Turbulent Heat ◽  
Cooling Process ◽  
Maximum Temperature Difference

A numerical study has been earned out to investigate the fluid flow structure and convective heat transfer due to a circular jet impinging on a rotating disk. The temperature distribution and convection heat transfer coefficient on the disk are calculated. Flow is considered to be steady, incompressible and turbulent. k-ε RNG model is used to model the turbulent flow. Two new criteria are introduced and used to evaluate the performance of cooling process which are maximum temperature difference on the disk and the average temperature of the disk. The first parameter shows the uniformity of temperature distribution in the disk and the second shows the effect of both thermo physical properties of the disk material and cooling process. In order to verify the numerical approach, results have been compared with the experimental data which shows a good agreement.

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