Improving the humidity resistance of electronic packaging materials by micro-nano hierarchical structured silica

Micro-nano structured silica particles were synthesized successfully by grafted 4,4´-diphenylmethane diisocyanate (MDI). We report a robust procedure for preparing superhydrophobic materials with the advancing water contact angle (WCA) of about 155°. Micro-nano structured surface roughness, which mimics the surface topology of self-cleaning plant leaves, originates from well-defined micro-nano structured silica particles that are covalently bonded to an epoxy-based polymer matrix. The roughened surface is chemically modified with a layer of n-octyltriethoxysilane. The morphology of the silica with micro-nano hierarchical structure was observed by SEM. Hierarchical structure of silica filled epoxy resin composite exhibits better humidity resistance than the neat epoxy resin. The results show that the hierarchical structure of silica filled epoxy resin composite is suitable for electronic packaging in humid environment.