A novel integrated structure of thin film GaN LED with ultra-low thermal resistance

Wen, Shih-Yi; Hu, Hung-Lieh; Tsai, Yao-Jun; Hsu, Chia-Hao; Lin, Re-Ching; Horng, Ray Hua

doi:10.1364/oe.22.00a601

Cited by 12 publications

(11 citation statements)

References 13 publications

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“…The thermal resistance are related with heat conduction path from the LED junction to die attach and then to the PI substrate [23]. Determination for the thermal resistance (R th ) of LED chip can be calculated by using the equation of R th = ΔT/(P e -P op ) [24]. The common thermal resistance of conventional face-up LED with direct eutectic bonding is 5~10 K/W [24].…”

Section: Measurement and Analysismentioning

confidence: 99%

“…Determination for the thermal resistance (R th ) of LED chip can be calculated by using the equation of R th = ΔT/(P e -P op ) [24]. The common thermal resistance of conventional face-up LED with direct eutectic bonding is 5~10 K/W [24]. In our design, the flexible white LED array was equipped with a copper heat spreader to gain better thermal resistance performance.…”

Section: Measurement and Analysismentioning

confidence: 99%

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Large-area, uniform white light LED source on a flexible substrate

et al. 2015

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This study demonstrates the flexible white LED structure with high lumen efficiency and uniform optical performance for neutral white and warm white CCT. Flip-chip LEDs were attached on a polyimide substrate with copper strips as electrical and thermal conduction paths. Yellow phosphors are mixed with polydimenthysiloxane (PDMS) to provide mechanical support and flexibility. The light efficiency of this device can reach 120 lm/W and 85% of light output uniformity of the emission area can be achieved. Moreover, the optical simulation is employed to evaluate various designs of this flexible film in order to obtain uniform output. Both the pitch between the individual devices and the thickness of the phosphor film are calculated for optimization purpose. This flexible white LED with high lumen efficiency and good reliability is suitable for the large area fixture in the general lighting applications.

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Section: Measurement and Analysismentioning

confidence: 99%

Section: Measurement and Analysismentioning

confidence: 99%

Large-area, uniform white light LED source on a flexible substrate

et al. 2015

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“…The choice of In-Au eutectic system here was due to the low stress in the In bumps at low temperatures (−25 °C to −20 °C), at which the detectors were operated. Also, eutectic bonding was implemented in packaging of GaN LED chips on Si substrates to enhance thermal dissipation [128], in vertical LEDs [129,130], in the development of high-power laser chips [131], as well as in the packaging of thermal imaging sensors [132] and micromirror arrays [133].…”

Section: Eutectic Bondingmentioning

confidence: 99%

Low-Temperature Bonding for Silicon-Based Micro-Optical Systems

Howlader

Deen

2015

Photonics

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Abstract:Silicon-based integrated systems are actively pursued for sensing and imaging applications. A major challenge to realize highly sensitive systems is the integration of electronic, optical, mechanical and fluidic, all on a common platform. Further, the interface quality between the tiny optoelectronic structures and the substrate for alignment and coupling of the signals significantly impacts the system's performance. These systems also have to be low-cost, densely integrated and compatible with current and future mainstream technologies for electronic-photonic integration. To address these issues, proper selection of the fabrication, integration and assembly technologies is needed. In this paper, wafer level bonding with advanced features such as surface activation and passive alignment for vertical electrical interconnections are identified as candidate technologies to integrate different electronics, optical and photonic components. Surface activated bonding, superior to other assembly methods, enables low-temperature nanoscaled component integration with high alignment accuracy, low electrical loss and high transparency of the interface. These features are preferred for the hybrid integration of silicon-based micro-opto-electronic systems. In future, new materials and assembly technologies may emerge to enhance the performance of these micro systems and reduce their cost. The article is a detailed review of bonding techniques for electronic, optical and photonic components in silicon-based systems.

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“…Effective system-level heat dissipation is vital, especially in relation to the miniaturization of the package size, and therefore, highly sophisticated yet cost-effective thermal management system is crucially needed, in particular the solid-state lighting technology such as light-emitting diodes (LEDs). Over the past few decades, LEDs have been vastly used as replacement of conventional lighting in various applications such as street lighting, advertisement, backlighting display, automotive and residential lighting (Wen et al , 2014; Park et al , 2006; Tseng et al , 2015). Unique characteristics of LEDs such as long lifetime, environment-friendly, high brightness and low power consumption have drawn the attention of multiple lighting industries, and it is also stated that the solid-state lighting industry will achieve overall annual growth rate of 12 per cent throughout 2017 (Hwang et al , 2007; Sagimori and Muto, 2010; Liul et al , 2013; http://ledsmagazine.com/features/10/3/4).…”

Section: Introductionmentioning

confidence: 99%

Performance of Cu-Al₂O₃ thin film as thermal interface material in LED package: thermal transient and optical output analysis

Lim

Devarajan

Shanmugan

2018

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Purpose This paper aims to study the influence of the Cu-Al2O3 film-coated Cu substrate as a thermal interface material (TIM) on the thermal and optical behaviour of the light-emitting diode (LED) package and the annealing effect on the thermal and optical properties of the films. Design/methodology/approach A layer-stacking technique has been used to deposit the Cu-Al2O3 films by means of magnetron sputtering, and the annealing process was conducted on the synthesized films. Findings In this paper, it was found that the un-annealed Cu-Al2O3–coated Cu substrate exhibited low value of thermal resistance compared to the bare Cu substrate and to the results of previous works. Also the annealing effect does not have a significant impact on the changes of properties of the films. Research limitations/implications It is deduced that the increase of the Cu layer thickness can further improve the thermal properties of the deposited film, which can reduce the thermal resistance of the package in system-level analysis. Practical implications The paper suggested that the Cu-Al2O3–coated Cu substrate can be used as alternative TIM for the thermal management of the application of LEDs. Originality value In this paper, the Cu substrate has been used as the substrate for the Cu-Al2O3 films, as the Cu substrate has higher thermal conductivity compared to the Al substrate as shown in previous work.

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A novel integrated structure of thin film GaN LED with ultra-low thermal resistance

Cited by 12 publications

References 13 publications

Large-area, uniform white light LED source on a flexible substrate

Large-area, uniform white light LED source on a flexible substrate

Low-Temperature Bonding for Silicon-Based Micro-Optical Systems

Performance of Cu-Al₂O₃ thin film as thermal interface material in LED package: thermal transient and optical output analysis

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A novel integrated structure of thin film GaN LED with ultra-low thermal resistance

Cited by 12 publications

References 13 publications

Large-area, uniform white light LED source on a flexible substrate

Large-area, uniform white light LED source on a flexible substrate

Low-Temperature Bonding for Silicon-Based Micro-Optical Systems

Performance of Cu-Al2O3 thin film as thermal interface material in LED package: thermal transient and optical output analysis

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Product

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Performance of Cu-Al₂O₃ thin film as thermal interface material in LED package: thermal transient and optical output analysis