High-power UV LED array for curing photoadhesives

Hubert, Manfred; Dimas, Chris F.; Orava, Paul; Koo, Joyce

doi:10.1117/12.543342

Cited by 6 publications

(5 citation statements)

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“…In the recent years, UV-LED light source has progressively emerged in various fields such as ink and printing, stereolithography, adhesive, hydrogel and wood coating [ 26 , 27 , 28 , 29 , 30 ]. This is because UV-LED consumes 50–75% less energy than the equivalent mercury arc lamp and has narrow wavelength distribution [ 27 , 28 , 29 ].…”

Section: Introductionmentioning

confidence: 99%

UV-LED as a New Emerging Tool for Curable Polyurethane Acrylate Hydrophobic Coating

et al. 2021

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The elimination of mercury, low energy consumption, and low heat make the ultraviolet light-emitting diode (UV-LED) system emerge as a promising alternative to conventional UV-mercury radiation coating. Hence, a series of hydrophobic coatings based on urethane acrylate oligomer and fluorinated monomer via UV-LED photopolymerisation was designed in this paper. The presence of fluorine component at 1160 cm−1, 1235 cm−1, and 1296 cm−1 was confirmed by Fourier Transform Infra-Red spectroscopy. A considerably high degree C=C conversion (96–98%) and gel fraction (95–93%) verified the application of UV-LED as a new technique in radiation coating. It is well-accepted that fluorinated monomer can change the surface wettability as the water contact angle of the coating evolved from 88.4° to 121.2°, which, in turn, reduced its surface free energy by 70.5%. Hence, the hydrophobicity of the coating was governed by the migration of the fluorine component to the coating surface as validated by scanning electron and atomic force microscopies. However, above 4 phr of fluorinated monomer, the transparency of the cured coating examined by UV-visible spectroscopy experienced approximately a 16% reduction. In summary, the utilisation of UV-LED was a great initiative to develop green aspect in photopolymerisation, particularly in coating technology.

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Section: Introductionmentioning

confidence: 99%

UV-LED as a New Emerging Tool for Curable Polyurethane Acrylate Hydrophobic Coating

et al. 2021

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“…UV LEDs are used, for example, to cleanse water by degrading organic pollutants in water, for example, dyes, pharmaceuticals, and insecticides [9,10]. Other applications include fluorescence detection [11], curing [12], photolithography [13], and biomedical research [14].…”

Section: Introductionmentioning

confidence: 99%

“…Commonly, LED arrays are designed with a specific purpose in mind, which sets limited requirements of the required irradiated area [8,11,12,14,[16][17][18][19]. However, some research fields require a modular and easily adjustable array design.…”

Section: Introductionmentioning

confidence: 99%

Development and Analysis of a Modular LED Array Light Source

et al. 2020

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Light emitting diodes (LEDs) have experienced rapid technological development in the past decade, making them a winning alternative to conventional light sources in many applications. LED arrays allow precise control of the desired irradiance profile in a target area by adjusting the position and output power of individual LEDs. However, despite increased efficiency, many LEDs still transform a large proportion of the input electrical power into heat, requiring an efficient cooling system. This paper presents a modular LED array light source mounted on a water-cooled aluminum plate. Novel electronic LED driver modules, connected via a serial communication bus in a daisy-chain topology, were developed with the ability to set the operating current of individual LEDs. A modular layout of cooling and mounting system and LED driver modules, as well as a specialized design for the LED soldering footprint, was able to house a variety of common commercial LEDs, enabling easy adjustment of the lighting system to the required application and size of the irradiated area. In a prototype of one plate containing 10 LEDs, individual LED radiance was optimized for a better irradiance homogeneity in the target area. Array characterization showed a low standard deviation of the irradiance of 1.8% and a good fit between measured and calculated irradiance. A test of the array at elevated temperatures showed moderate LED radiance degradation and a wavelength shift of the measured spectra after extended use.

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“…Ultraviolet light emitting diode (UV LED) has the advantages of small size, long lifetime, and high efficiency. It is used in fluorescence detection, high-resolution microscope, UV exposure, UV curing, medical application, biological analysis, and other fields have a wide range of application prospects [1][2][3]. According to the peak wavelength of the spectrum, ultraviolet LED is divided into three categories: UVA (315 nm < λ ≤ 420 nm), UVB (280 nm < λ ≤ 315 nm), and UVC (200 nm < λ ≤ 280 nm).…”

Section: Introductionmentioning

confidence: 99%

The Effect of Package Structure on the Light Extraction Efficiency of Near-Ultraviolet LED

2019

International Journal of Photoenergy

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The near-ultraviolet high-power LED, with five package structures, is designed and fabricated. The efficiency of electric conversion to light (EECL) of various package structures is measured, and the EECL is used to characterize the light extraction efficiency (LEE) of the package structure. By analyzing the Fresnel loss (FNL) and total inner reflection loss (TIRL) of light at different interfaces, the experimental results are explained qualitatively. When approximate spherical lens is used, filling silica gel between chip and lens can improve the LEE. The EECL of the device can reach 66.84%, which is higher than that of bare chip by 55.10%. In planar packaging, the EECL of the device is lower than that of the bare chip, whether or not it is filled with silica gel. After filling with silica gel, a new TIRL is produced at the final interface of the device, and the EECL of the device is even lower, which is only 37.14%. The experimental results show that when the LED chip adopts graphic substrate and surface microstructure to improve the LEE, the traditional coating of silica gel (or epoxy) and other materials on the chip surface may not improve the LEE of the device. If the introduction of the silica gel layer leads to a new total inner reflection interface, it will result in a significant decrease in LEE of the device. When a layer, such as silica gel, does not result in a new total reflection interface, the FNL and TIRL of the chip surface can be effectively reduced, and the LEE of the LED device can be improved.

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High-power UV LED array for curing photoadhesives

Cited by 6 publications

References 0 publications

UV-LED as a New Emerging Tool for Curable Polyurethane Acrylate Hydrophobic Coating

UV-LED as a New Emerging Tool for Curable Polyurethane Acrylate Hydrophobic Coating

Development and Analysis of a Modular LED Array Light Source

The Effect of Package Structure on the Light Extraction Efficiency of Near-Ultraviolet LED

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