Lumen degradation analysis of LED lamps based on the subsystem isolation method

Abstract

The lumen degradation of LED lamps undergoing an accelerated aging test is investigated. The entire LED lamp is divided into three subsystems, namely, driver, lampshade, and LED light source. The parameters of output power [Watts (W)], transmittance (%), and lumen flux (lm) are adopted in the analysis of the degradation of the driver, lampshade, and LED light source, respectively. Two groups of LED lamps are aged under the ambient temperatures of 25°C and 85°C, respectively, with the aging time of 2000 h. The lumen degradation of the lamps is from 3.8% to 4.9% for the group under a temperature of 25°C and from 10.6% to 12.7% for the group under a temperature of 85°C. The LED light source is the most aggressive part of the three subsystems, which accounts for 70.5% of the lumen degradation of the LED lamp on average. The lampshade is the second degradation source, which causes 21.5% of the total amount on average. The driver is the third degradation source, which causes 6.5% under 25°C and 2.8% under 85°C of the total amount on average.

Machine Learning and Digital Twin Driven Diagnostics and Prognostics of Light‐Emitting Diodes

“…Recently, Ke et al. [ 74 ] introduced a subsystem isolation method to estimate the lumen degradation LED lamps and the result showed lumen degradation of 70.5% due to the LED emitter, 21.5% the optical part, and 6.5% the driver, which contradicts the two studies (USDOE [ 212 ] and Van Driel et al. [ 213 ] ) previously mentioned.…”

“…• Cracking of chip/die • Yellowing and cracking of the encapsulating lens [63] • Package epoxy browning [75] System level (LED chips, modules, diffuser, reflector, electrical driver), [ 51,55,56] Colaco et al, [ 56,61,64,66,68,74] Colaco et al [ 57,76] • Lumen depreciation [ 68,74,56,57] • Color shift [ 51,64,76] • eventually cause lumen flux depreciation and change the chromatic properties of the LEDs. The failure mechanisms at the interconnections can be fracture of the bond wire as well as fatigue on the wire ball bond due to thermal and electrical overstress, electrical contact degradation due to metallurgical interdiffusion, and electrostatic discharge (resulting in rapid failure due to the open circuit).…”

Difusor polimérico de lâmpada WLEDi do mercado brasileiro

“…Lâmpada WLEDi com base Edison, subdividida (da esquerda para a direita) em: difusor, módulo LED, corpo (com dissipador de calor e base tipo E-27) e driver (circuito eletrônico) 3 .…”

“…Em experimento realizado com esses tipos de lâmpadas (consideradas neste trabalho como WLEDi -lâmpadas LED de emissão branca) por Ke e colaboradores, a lâmpada LED foi dividida em diferentes partes, como ilustrada na Fig. 1 3 . As três partes principais consideradas por esses autores foram: o driver, o difusor e a fonte de luz (módulo com os LEDs).…”

Improving optical properties of remote phosphor LED using green Y2O3:Ho3+ and red Mg4(F)(Ge, Sn)O6:Mn2+ layers

“…The QDs and the phosphor are blended together and put on the LED chip in the first configuration, the combined configuration [17,18], while in the latter configuration the QDs and phosphor layer are applied individually onto the chip, as separated configuration [19,20]. The issue with the combined configuration is the QDs in this structure is part of the reflector and, therefore, too close to the LED chip and results in high optical density.…”