Discussion on Failure Mechanism and Modeling of Electrochemical Migration of High Density Printed Circuit Boards in Dust Environment

With the continuous development of science and technology, the use of printed circuit board (PCB) with high density is becoming more and more widespread. The reduction of the spacing between adjacent wires makes the PCB more prone to electrochemical migration (ECM), which eventually leads to the insulation failure. When the airborne dust deposits on PCB under severely polluted environment, the critical humidity, the ion concentration and the local temperature on PCB surface will be changed, which can increase the complexity of the ECM failure and degrade the reliability of the system. In this paper, the previous research about the failure mechanism and influencing factors of ECM are summarized. The time to failure (TTF) models of ECM are also discussed and compared. The potential impacts of dust contamination on the failure mechanism of ECM and life models of ECM of PCB are analyzed and proposed as a question for further investigation.