Anti-Corrosion Capacity Validation for Anti-Sulfur Type Electronic Passive Components by Way of Various Flower-of-Sulfur (FoS) Methodologies

Hardware reliability of Information Technology (IT) equipment can be easily affected by corrosive gases, moisture, contaminants and particulate matter. It can potentially cause electrical open failures due to sulfur corrosion (Ag
2
S) on the inner electrode of electronic passive components. In order to improve the robustness against sulfur corrosion, many vendors adopted gold-based and silver-palladium-based inner electrode designs (noble metal) as well as other solutions, including passivation cover and reverse structure designs. New IT equipment applications, including Artificial Intelligence (AI), Big Data, 5G, Internet of Things (IoT) and Edge Computing in recent years has proliferated the need of passive electronic components and the industry is facing passive component shortage. Therefore, quality control is becoming more critical in reducing poor quality risk. Flowers of Sulfur (FoS) is a popular method to validate the anti-sulfur corrosion capability of electronic passive components. However, the condition of single corrosive gas (sulfur vapor) is not enough to represent the accelerated corrosion exposure in field environments. It has been stipulated that typical testing methods as outlined in ASTM B809 and EIA-977 may not be totally effective in driving Anti-Sulfur Resistor (ASR) failure occurrence at 105°C/750 hours (test to pass), or even longer duration. Despite testing at those conditions, end-customers have reported sulfur corrosion-related failures. Therefore, it is necessary to develop an effective accelerated method for anti-sulfur corrosion capacity validation for anti-sulfur type electronic passive components. In this paper, three conditions of FoS test were carried out to validate the anti-sulfur corrosion capability of ASR components. We introduced chlorine-gas as another acceleration factor, and benchmarked it against ASTM B809 and EIA-977 FoS tests. Several analytical methods were used in this work, including, high resolution 3D X-Ray Microscope (3D X-Ray), Cross section polisher, (CP), Plasma Focused Ion Beam, (PFIB), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX). Finally, we found that FoS with chlorine-gas condition is the most aggressive of all conditions.