LED Lifetime Prediction Under Thermal-Electrical Stress

Tan, Kai-Zhe; Lee, See-Keong; Low, Heng-Chin

doi:10.1109/tdmr.2021.3085579

Cited by 20 publications

(11 citation statements)

References 18 publications

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“…Lifespan 1 Lifespan of LED lights is about 40,000-70,000 H [7][8][9] under ideal conditions, this is longer than HPSL or fluorescent light sources.…”

Section: Energy Consumptionmentioning

confidence: 99%

Reliability Enhancement Driven by ANN for Lighting Control System in Highway Tunnels

Zeng³

et al. 2022

Applied Sciences

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Compared with open roadways, traffic safety in highway tunnels requires more attention to build smoothly transitioned and well-coupled light environments for drivers to alleviate visual discomfort so as to achieve a balanced sense of driving safety and comfort. In this study, in order to overcome the drawbacks of existing tunnel lighting control modes that disregard the color temperature of natural light characteristics and collaborative influence of color temperature and luminance of natural light on tunnel lighting quality, one artificial neural network (ANN) model is designed and trained to simulate one physical lighting control system that takes into consideration color temperature and luminance simultaneously. In this model, multiple parameters of discrete and continuous types of input layer and output layer are synergistically analyzed. The model was also trained with quantities of field data from one tunnel in service and includes one hidden layer with 10 neurons. The simulation results showed that this model obtains a high degree of fitness with inside luminance and 100% recognition rate with inside color temperature in the threshold zone, which conforms to the regulation strategy of actual lighting control systems with high confidence. The proposed model will greatly enhance the reliability and sustainability of the lighting system during its normal operation, which can also support other lighting scenarios due to its flexibility and scalability with multiple-input and multiple-output (MIMO) capabilities.

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“…Lifespan 1 Lifespan of LED lights is about 40,000-70,000 H [7][8][9] under ideal conditions, this is longer than HPSL or fluorescent light sources.…”

Section: Energy Consumptionmentioning

confidence: 99%

Reliability Enhancement Driven by ANN for Lighting Control System in Highway Tunnels

Zeng³

et al. 2022

Applied Sciences

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“…Mechanisms accelerated by temperature are typically modeled using the Arrhenius equation [37]. Additional aging parameters, such as current, can be taken into account by Black's equation, which was initially developed to describe the process of electromigration in semiconductors [38], [39]. Therefore, the time to failure (TTF) is given by the two assumed independent variables of junction temperature T j and stress current I a using…”

Section: Introductionmentioning

confidence: 99%

“…Model parameters such as activation energy E a , exponent n and coefficient K can be determined by using stress test data collected at different current and temperature conditions, whereas k B correspondents to the Boltzmann constant. Another possibility of accelerated lifetime modeling is given by the Eyring model [39]. The model allows a consideration of thermal and several non-thermal factors and their interactions, but it's not considered in depth for the modeling part of this publication.…”

Section: Introductionmentioning

confidence: 99%

Lifetime Prediction of Current-and Temperature-Induced Degradation in Silicone-Encapsulated 365 nm High-Power Light-Emitting Diodes

et al. 2023

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We report on the degradation mechanisms and dynamics of silicone encapsulated ultraviolet A (UV-A) high-power light-emitting diodes (LEDs), with a peak wavelength of 365 nm. The stress tests were carried out for a period of 8665 hours with forward currents between 350 mA and 700 mA and junction temperatures up to 132 • C. Depending on stress condition, a significant decrease in optical power could be observed, being accelerated with higher operating conditions. Devices stressed at a case temperature of 55 • C indicate a decrease in radiant flux between 10 -40 % varying with measurement current, whereas samples stressed at higher case temperatures exhibit crack formation in the silicone encapsulant accompanied by electromigration shorting the active region. The analyzed current and temperature dependency of the degradation mechanisms allows to propose a degradation model to determine the device lifetime at different operating parameters. Additional stress test data collected at different aging conditions is used to validate the model's lifetime predictions.

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“…The article [11] focuses on the spatial distribution uniformity of luminous intensity. In [12], the effectiveness of the Eyring model as a lumen maintenance life prediction model for thermal-electrical operating conditions was investigated. The step-stress temperature accelerated aging test was performed in [13].…”

Section: Introductionmentioning

confidence: 99%

Analysis and Recommendations for LED Catastrophic Failure Due to Voltage Stress

2022

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Light-emitting diode (LED) lighting has, compared to other types of lighting, a significantly lower energy consumption. However, the perceived service life is also important for customer satisfaction and here there is a discrepancy between customers’ experience and manufacturers’ statements. Many customers experience a significantly shorter service life than claimed by the manufacturers. An experiment was carried out in the Pehr Högström Laboratory at Luleå University of Technology in Skellefteå, Sweden to investigate whether voltage disturbances could explain this discrepancy. Over 1000 LED lamps were exposed to high levels of voltage disturbances for more than 6000 h; the failure rate from this experiment was similar to the one from previous experiments in which lamps were exposed to normal voltage. The discrepancy thus remains, even though some possible explanations have emerged from the project’s results. The lamps were exposed to five different types of voltage disturbances: short interruptions; transients; overvoltage; undervoltage; and harmonics. Only overvoltage resulted in failure of the lamps, and only for a single topology of lamp. A detailed analysis has been made of the topology of lamps that failed. This lamp type contains a different internal electronics circuit than the other lamp types. Failures of the lamps when exposed to overvoltage are due to the heat development in the control circuit increasing sharply when the lamps are exposed to a higher voltage. Hence, it is concluded that there are lamps that are significantly more sensitive to voltage disturbances than other lamp types. Manufactures need to consider the voltage quality that can be expected at the terminal of the lamp to prevent failure of lamps due to voltage disturbances. This paper therefore contains recommendations for manufacturers of lighting; the recommendations describe which voltage disturbances lamps should cope with.

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LED Lifetime Prediction Under Thermal-Electrical Stress

Cited by 20 publications

References 18 publications

Reliability Enhancement Driven by ANN for Lighting Control System in Highway Tunnels

Reliability Enhancement Driven by ANN for Lighting Control System in Highway Tunnels

Lifetime Prediction of Current-and Temperature-Induced Degradation in Silicone-Encapsulated 365 nm High-Power Light-Emitting Diodes

Analysis and Recommendations for LED Catastrophic Failure Due to Voltage Stress

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