Prognostics of radiation power degradation lifetime for ultraviolet light-emitting diodes using stochastic data-driven models

Fan, Jiajie; Zhou, Jing; Cao, Yixing; Ibrahim, Mesfin Seid; Min, Li; Fan, Xuejun; Zhang, Guoqi

doi:10.1016/j.egyai.2021.100066

Cited by 5 publications

(1 citation statement)

References 31 publications

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“…Evidence for silicone cracking was found in UV-14 DUTs after RTOL-1, and dark spots were found in the silicone layer for UV-12 after RTOL-1 but not after RTOL-2. This conclusion is based on general observations and knowledge of the impact of degradation of some silicones under UV radiation [9,[29][30][31][32]; however, confirmation of the impact of silicone yellowing on the high parametric failure rates for these products could not be determined within the scope of this study. For UV-13, the high parametric failure rate during RTOL-1 may be because of the high Tsp value during the first 92 hrs of operation, especially because acceptable RFM values were measured for UV-13 throughout RTOL-2 in which Tsp was much lower.…”

Section: Uv-4 Uv-6mentioning

confidence: 81%

Operating Lifetime Study of Ultraviolet (UV) Light-Emitting Diode (LED) Products

Davis

Rountree

Pope

et al. 2022

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Light-emitting diodes (LEDs) can emit radiation that spans the range from near infrared (IR) to all three bands of ultraviolet (UV) radiation: UV-A, UV-B, and UV-C. This report focuses on LEDs that emit in one of the three UV bands because they have the potential to displace lowpressure mercury vapor (LPMV) lamps in a variety of industrial processes, including ink and adhesive curing, medical procedures, and germicidal disinfection. However, before emerging UV LED technologies can displace LPMV lamps, the efficiency and reliability of these sources must meet the user's expectations in each application. An earlier report focused on the construction and initial performance of commercial UV LED products in radiometric and current-voltage (I-V) tests [1]. This report focuses on the long-term performance and reliability of the same set of commercial products. The intent of this report is to provide to the lighting industry a benchmark of the state of UV LEDs as of mid-2021 when these products were purchased. Understanding the failure modes and failure rates of UV LEDs is important in improving UV product reliability at the LED, lamp, and luminaire level and is critical to developing products with higher efficiency, lower carbon footprint, and significantly reduced environmental impact than LPMV lamps.Operating Lifetime Study of Ultraviolet (UV) Light-Emitting Diode (LED) Products viii maintenance [RFM] was 0.50 or lower). Four products (i.e., UV-3, UV-5, UV-9, and UV-11) did not experience any failures during RTOL-1, but the other nine products had failure rates ranging from 10% to 100%. The most common failure mode was a parametric failure, which accounted for 50 failures during the test. Only seven DUTs failed abruptly, and four out of these seven devices were UV-2 DUTs. These findings demonstrate that there is a wide range of reliability in commercially available UV LED products.Different DUTs of the 13 UV LED products were divided into two groups for RTOL-2 based on their power rating. Group-A, which had If values less than 55 milliampere (mA), was operated for 2,500 hrs during RTOL-2, whereas Group-B, which had If values greater than 100 mA, was operated for 3,000 hrs during RTOL-2. Even though product operation times were longer in RTOL-2 compared with RTOL-1, the cumulative failure rate was lower, as might be expected for the milder stress conditions (i.e., lower If values). A total of 32 failures occurred during RTOL-2 (which is 25% of the total product population): 11 abrupt failures and 21 parametric failures. This finding corresponds to a cumulative failure rate of 25%. Most of the failures during RTOL-2 were concentrated in fewer products; this observation was in contrast to findings from RTOL-1, during which failures were more widespread. For example, during RTOL-2, 7 abrupt failures occurred in the UV-2 DUTs and a greater than 50% parametric failure rate was measured for the UV-8 and UV-14 DUTs. These three products accounted for 22 out of the 32 failures recorded in RTOL-2.Based on this work and combine...

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