Modeling of moisture diffusion in heterogeneous epoxy resin containing multiple randomly distributed particles using finite element method

The moisture diffusion phenomenon of UV-curable adhesive apply to the packaging of organic light-emitting devices (OLEDs) were investigated. Owing to the sensitivity of moisture ingress into OLEDs package, how to against the moisture permeation will be one of the key design issue. As regards to improve the moisture-resistant capability of the materials for encapsulating, one possible way is to add particles into UV-curable sealing adhesive. In this study, a numerical simulation model that contained randomly distributed particles into heterogeneous epoxy resin has been developed. The commercial software MATLAB is employed to generate the location of randomly distributed particles and the commercial software ANSYS based on the finite element method is employed to analyze moisture diffusion in containing multiple randomly distributed particles. Furthermore, this model is then employed to investigate the relationship between the volume fraction of the particles in the resin composite and the rate of moisture diffusion. The simulation results show that moisture diffusion is retarded significantly as the volume fraction of particles increases. Moreover, the adhesive with high volume fraction of particle exhibits superior moisture-resistant capability. However, excessively add particles makes inferior penetrability. Therefore, adding proper volume percentage of particle into UV-curable adhesive could be expected better using in engineering applications.