Enhanced Thermal Dissipation and Light Output of GaN/Sapphire Light-Emitting Diode by Direct Cu Electroplating

Horng, Ray−Hua; Chiang, C. C.; Wuu, Dong−Sing; Hsiao, Hsin-Huang Michael; Lin, H. I.

doi:10.1149/1.2972992

Cited by 6 publications

(4 citation statements)

References 9 publications

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“…We also remark that the VTF-LED exhibits a linear increase of the optical power with the current injection increase up to 500 mA (limit of our equipment), without any saturation as in the case of the lateral LED for injected current larger than 200 mA for which current crowding and the associated heating effect begin to degrade the LED efficiency. This heating effect is greatly reduced thanks to better current injection in the vertical structure and to the copper substrate, which acts as a heat sink permitting good thermal dissipation in the case of the VTF-LED, as it has been reported by Horng et al…”

Section: Resultsmentioning

confidence: 81%

“…In recent years, innovation in high-brightness GaN-based light-emitting diodes (LEDs) has enabled the next-generation solid-state lighting, displays, and visible light communication systems . However, conventional laterally contacted LEDs grown on insulating sapphire substrates suffer from (i) high series resistance caused by a lateral current path and by current crowding near the edge of the contact, , (ii) poor heat dissipation when operated at high current density due to the low thermal conductivity of the substrate, and (iii) limited top surface emission owing to the extensive coupling of light in the thick transparent sapphire substrate. , To overcome these issues, vertical thin-film LEDs (VTF-LEDs), where the sapphire substrate is removed and the LED structure is transferred to an electrically conductive host substrate, have been widely investigated. In this configuration, electrical contacts are deposited on both sides of the functional epilayers.…”

Section: Introductionmentioning

confidence: 99%

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Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer

Karrakchou

Gujrati

Vuong

et al. 2021

ACS Appl. Electron. Mater.

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We demonstrate the fabrication of vertical InGaN light emitting diodes on large-area freestanding membranes, using a mechanical lift-off technique enabled by 2D h-BN. 30-μm-thick electroplated copper deposited on the epilayer (i) gives rigidity to the structure, preventing crack generation, (ii) functions as a back mirror and as a heat sink, and (iii) enables one-step self-lift-off and transfer of LED structures from h-BN/sapphire during a thermal treatment at 100°C. Free-standing arrays of LEDs on thick membranes were processed and their electro-optical performance characterized. This approach can provide a solution for the fabrication of low cost, wafer scale, crack-free, and highly reproducible free-standing arrays of vertical LEDs with up to centimeter-size areas.

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Section: Resultsmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer

Karrakchou

Gujrati

Vuong

et al. 2021

ACS Appl. Electron. Mater.

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show abstract

“…The use of electroplating technology has improved the performance of GaN-based LEDs in solid-state lighting applications [1][2][3][4]. However, using electroplating technology adds an extra process to LED manufacturing because laser lift-off (LLO) technology must be used, causing LED manufacturers have low throughput, low yield, and high cost.…”

Section: Introductionmentioning

confidence: 99%

Connecting plugs of high-powered GaN-based lighting-emitting diodes prepared by electroplating

Wang

Chen

2013

Materials Science in Semiconductor Processing

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“…However, a reflective mirror for the LED module has not been designed. Horng et al (2008) introduced a micro‐reflective cup fabricated by Cu electroplating to form a direct spread LED module to enhance the thermal dissipation.…”

Section: Introductionmentioning

confidence: 99%

Parametric study of efficient thermal dissipation in an LED back light unit

Kim

Lee

Kim

et al. 2011

Microelectronics International

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Purpose -Thermal management under high heat flux is crucial to developing high-power light-emitting diode (LED) applications. The purpose of this paper is to propose an efficient thermal dissipation technique for an LED back light unit (BLU) system. Design/methodology/approach -A typical BLU system includes an LED package (GaN on sapphire, cathode/anode, silicone encapsulant, resin plus phosphor) on a printed circuit board (PCB), a light guide panel, and an aluminum cover frame. The temperature distribution of this system has been simulated and the thermal behavior within a 3D model has been investigated using a commercial computational fluid dynamic code (FLUENT 6.3). Findings -The authors examined the heat-spreading effect of cover lengths ranging from 6 to 300 mm and also observed the effect of back cover thickness on the junction temperature and cover frame temperature and investigated the influence of the air gap between the package and the cover frame. Removing the air gap lowers the maximum temperature by about 6 percent. It was found that the addition of a copper layer covering the external surfaces of the LED chip enhanced the cooling efficiency. Finally, the maximum junction temperature can be decreased by more than 21 percent in the range of parameters considered by removing the air gap, adding a heat spreader, and using a thick cover frame. Originality/value -In this paper, thermal management for efficient heat spreading through a typical BLU system without using any additional devices is investigated. Several parameters that increase the system's temperature are examined, and a combination of design features that attenuate the junction temperature is proposed.

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Enhanced Thermal Dissipation and Light Output of GaN/Sapphire Light-Emitting Diode by Direct Cu Electroplating

Cited by 6 publications

References 9 publications

Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer

Monolithic Free-Standing Large-Area Vertical III-N Light-Emitting Diode Arrays by One-Step h-BN-Based Thermomechanical Self-Lift-Off and Transfer

Connecting plugs of high-powered GaN-based lighting-emitting diodes prepared by electroplating

Parametric study of efficient thermal dissipation in an LED back light unit

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