A design and qualification of LED flip Chip-on-Board module with tunable color temperatures
| Autor: | Jianwu Cao, Jiajie Fan, Guoqi Zhang, Chaohua Yu, Xuejun Fan, Cheng Qian |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Spectral power distribution business.industry 020208 electrical & electronic engineering 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Luminous flux Chip-scale package High color 0202 electrical engineering electronic engineering information engineering Optoelectronics Junction temperature Wafer Electrical and Electronic Engineering 0210 nano-technology Safety Risk Reliability and Quality business Luminous efficacy Flip chip |
| Zdroj: | Microelectronics Reliability. 84:140-148 |
| ISSN: | 0026-2714 |
| Popis: | with the increasing requirements on guaranteeing the color uniformity and improving the luminous efficacy and manufacturing efficiency, a wafer level chip scale packaging (WLCSP) technology has been developed by thermally impressing a thin multiple phosphor film on a LED wafer, then being segmented into individual LED chips. In this paper, a high power white LED Chip-on-Board (COB) module with high color rendering index (CRI, Ra > 93) and tunable correlated color temperatures (CCTs) is prepared by the flip chip technology. In this COB module, the tunable color temperatures are achieved by using two types of white LED CSPs with different target CCTs of 3000 K and 5000 K. The thermal and photochromatic properties and the photochromatic stability of the COB module are studied through both experiments and simulations. The results show that: 1) The measured spectral power distribution (SPD) intensity of the prepared COB module is smaller than the arithmetic sum of SPD intensities of its each series connected CSPs, which may be attribute to the light absorption happened among CSPs; 2) The junction temperature and driven current have the different effects on the photochromatic properties of COB module (i.e. luminous flux, CCT and CRI); 3) The nonlinearity of luminous flux as a function of driven current and junction temperature should be considered in its modeling. |
| Databáze: | OpenAIRE |
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