Weathering barrier enhancement of printed circuit board by fluorinated silica based superhydrophobic coating

Superhydrophobic coating was firstly applied on printed circuit board (PCB) based on fluoroalkylsilane modified silica colloid suspension in methyl triethoxysilane solution. Through a feasible sol-gel method and subsequent curing process, we prepared a superhydrophobic coating on PCB that exhibits high water contact angle (CA) of 158 degrees and low sliding angle (SA) of 3 degrees. Weathering test results verify that the superhydrophobic coating not only has good waterproof and self-cleaning capability, but also performs well in protecting against UV irradiation or strong acid or base solution to some extent. Further electrochemical tests indicate that the superhydrophobic coating on the PCB-Cu and PCB-Sn electrodes shows excellent corrosion resistance in 1 wt.% NaCl aqueous solution with 99.6% and 98.7% inhibition efficiency respectively. In addition, the thin superhydrophobic coating (similar to 2 mu m) may endow the underlying PCB with promising heat dissipation ability. Therefore, it can be concluded that the superhydrophobic coating could dramatically increase the weathering resistance of PCB.