The phosphor and die bonding configuration affect the optical efficiency and thermal performance in phosphor-coated white light emitting diodes (LEDs). In this paper, light emission studies reveal that the chromaticity shift and light extraction losses depend on the uniformity of phosphor particles deposited over the LED surface. A nonuniform and sparse phosphor layer affects the correlated color temperature (CCT) and the spectral Y–B ratio due to the disproportionate contribution of light emission between the LED device and the phosphor layer. Furthermore, the Y–B ratio was observed to reduce with temperature due to higher Stoke's energy and light extraction losses in the phosphor layer. As a result, the Y–B ratio exhibits an inverse relationship with the package's thermal resistance as a function of temperature. On the other hand, the thermal performance of a LED package is dependent on the die-bonding configurations (conventional and flip-chip). Due to the improved heat dissipation capabilities in flip-chip bonding, the temperature rise and thermal resistance of the package were observed to reduce with temperature. By alleviating the heat accumulation in the package, more stable colorimetric properties such as CCT and Y–B ratio can be achieved.
Effect of Packaging Architecture on the Optical and Thermal Performances of High-Power Light Emitting Diodes
Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the JOURNAL OF ELECTRONIC PACKAGING. Manuscript received September 24, 2016; final manuscript received February 13, 2017; published online June 14, 2017. Assoc. Editor: Xiaobing Luo.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Law, T. K., Lim, F., Li, Y., Puan, X., Sng, G. K. E., and Ronnie Teo, J. W. (June 14, 2017). "Effect of Packaging Architecture on the Optical and Thermal Performances of High-Power Light Emitting Diodes." ASME. J. Electron. Packag. September 2017; 139(3): 031003. https://doi.org/10.1115/1.4036066
Download citation file:
- Ris (Zotero)
- Reference Manager