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

A. Herrmann; S.J.F. Erich; L.G.J.v.d. Ven; H.P. Huinink; W.D. van Driel; M. van Soestbergen; A. Mavinkurve; F. De Buyl; J.M.C. Mol; O.C.G. Adan

Optical Materials: X (May 2020)

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

A. Herrmann,
S.J.F. Erich,
L.G.J.v.d. Ven,
H.P. Huinink,
W.D. van Driel,
M. van Soestbergen,
A. Mavinkurve,
F. De Buyl,
J.M.C. Mol,
O.C.G. Adan

Affiliations

A. Herrmann: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands; Corresponding author.
S.J.F. Erich: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands; TNO, P.O. Box 49, 2600 AA, Delft, the Netherlands
L.G.J.v.d. Ven: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands
H.P. Huinink: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands
W.D. van Driel: Signify, High Tech Campus, Eindhoven, the Netherlands; Delft University of Technology, EEMCS Faculty, Delft, the Netherlands
M. van Soestbergen: NXP Semiconductors, Gerstweg 2, Nijmegen, 6534 AE, the Netherlands
A. Mavinkurve: NXP Semiconductors, Gerstweg 2, Nijmegen, 6534 AE, the Netherlands
F. De Buyl: Dow Silicones Belgium Sprl, Industrial Park – Zone C, 7180, Seneffe, Belgium
J.M.C. Mol: Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD, Delft, the Netherlands
O.C.G. Adan: Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, the Netherlands; TNO, P.O. Box 49, 2600 AA, Delft, the Netherlands

Journal volume & issue: Vol. 6

Abstract

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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.

Published in Optical Materials: X

ISSN: 2590-1478 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Engineering (General). Civil engineering (General): Applied optics. Photonics; Science: Physics: Optics. Light
Website: https://www.journals.elsevier.com/optical-materials-x

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