The influence of phosphor particles on the water transport in optical silicones for LEDs

Journal article (2020)

Authors

A. Herrmann Eindhoven University of Technology
S. J.F. Erich TNO, Eindhoven University of Technology
L.G.J. van der Ven Eindhoven University of Technology
HP Huinink Eindhoven University of Technology
W.D. van Driel Signify, Electronic Components, Technology and Materials - EEMCS
M. van Soestbergen NXP Semiconductors
A. Mavinkurve NXP Semiconductors
Francois De Buyl Dow Silicones
J.M.C. Mol (OLD) MSE-6
O. C.G. Adan TNO, Eindhoven University of Technology
Research Group
Electronic Components, Technology and Materials (EEMCS) (TU Delft)
Copyright: © 2020 A. Herrmann, S. J.F. Erich, L.G.J. van der Ven, H.P. Huinink, W.D. van Driel, M van Soestbergen, A Mavinkurve, Francois De Buyl, J.M.C. Mol, O. C.G. Adan
DOI: https://doi.org/10.1016/j.omx.2020.100047
More Info
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Published Date

2020

Language

English

Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Microelectronics

Research Group

Electronic Components, Technology and Materials

Abstract

The reliability of LEDs decreases in moist environments. One potential gateway of moisture ingress, reducing the product lifetime is the lens. In white LEDs, phosphor particles are embedded into the optical silicone of the lens to convert the blue light emitted by the diode down in frequency and achieve a light output that appears white. In this study, the influence of these phosphor particles on the moisture sorption, permeation and diffusion in optical silicones is investigated by comparing two silicone resins that are commonly used in LEDs, both with and without the addition of phosphor particles. The results of two methods are compared: the wet-cup method and a gravimetric approach of dynamic vapour sorption (DVS). Diffusion coefficients between 20 and 75 °C are reported as well as sorption isotherms, activation energy and sorption enthalpy. It is concluded that the addition of phosphor particles only has a very small impact on the moisture transport properties of the silicones.