Preparation and properties of a superhydrophobic surface on the printed circuit board (PCB)

Printed circuit board (PCB) and electronic components are widely used in practical applications. However, PCB and electronic components are not waterproof. When exposed to water vapor or corrosive liquid, it is easy to make electronic equipment short circuit, thus reducing its service life in practical applications. To solve this problem, an effective and low-cost superhydrophobic coating was prepared on the PCB. First, the solution prepared by hydrophobic nano-silica (Nano-SiO2) and dimethyl silicone oil (DSO) was sprayed on the PCB surface. Then, the surface was further modified with stearic acid (SA), and thus, a superhydrophobic surface with a water contact angle (WCA) of 160.24° and water sliding angle (WSA) of 3.5° was obtained. In a series of tests such as being placed under water for 10 h, at constant temperature (70 °C) and humidity (100%RH) chamber for 10 h, and outdoors for 8 months, the superhydrophobic coating on the PCB surface showed excellent water resistance. In addition, the coating had excellent stability against acid and alkali liquids, drinks, inks, etc. The coating fully solved the shortcoming of low water resistance of PCB and electronic components, and showed great potential application.