Screen-printed atmospheric corrosion monitoring sensor based on electrochemical impedance spectroscopy

An electrochemical sensor was developed for corrosion monitoring of a circuit board. The sensor was fabricated by using a screen-printing technique. The pattern of the sensor was a single comb-like structure of silver wiring. The impedance of the sensor was measured in wet and dry conditions. In wet condition, the impedance decreased immediately after water films generation and then gradually increased. In addition, a capacitive loop appeared and became large with growth of the water films. The experimental results could be simulated by using two equivalent circuits. In addition, the sensor was examined for the corrosion in dry sulfur gas. In the sulfur gas condition, the resistance of the sensor was proportional to the exposure time, since the silver surface reacted with sulfur at constant reaction rate. Therefore, the present sensor is potentially applicable to many corrosion conditions of circuit boards.