Development of novel methodology for electrochemical migration evaluation: high humidity condensation test

Electrochemical migration (ECM) represents an eminent reliability issue in electronic devices. However, standard evaluation methods are either time-consuming and require costly equipment or neglect essential phases, such as moisture condensation. Therefore, this paper introduces a novel testing method, the high-humidity condensation test (HHCT), as an advanced, reproducible measurement methodology for ECM evaluation. As with standard methods, the physical quantity measured is time-to-failure (TTF). The failure metric is a sudden surge in in-situ monitored electrical current between the DC-biased electrodes on the printed circuit board (PCB). The HHCT is realised in a sealed container with heated distilled water. This creates a moisture-saturated environment, accelerating condensation and ECM onset. The prototype used in this work was also equipped with a specialised holder, enabling ECM testing on inclined surfaces to better reflect real conditions. The results reveal that the HHCT demonstrates high consistency with the established water drop test (WDT) regarding the dependency of TTF on voltage and contamination. The mean TTFs were longer than those recorded in the WDT; nevertheless, the HHCT yielded results within several minutes to two hours. Furthermore, the HHCT established a clear correlation between TTF and the PCB inclination. Methodological robustness, repeatability, and measurement certainty are ensured by utilising strict run-to-run environmental controls, identical sample sizes, and standardised electrical failure criteria, supported by in-situ optical monitoring of dendrite growth. By transitioning from open bulk water to a stable condensation environment, the proposed configuration advances ECM evaluation from an empirical WDT to a quantifiable measurement methodology.