Pre-mature Reliability Degradation of 5G Network Electronics in Unknown Hostile Environment

This study focuses on the unexpected early reliability failure of an electronic network product for 5G transmission on the train system. The product began to experience communication failures after deployed in a European country for around 2 years. The investigation revealed that the electronic component inside the product had an open circuit, which was caused by corrosion from sulfur in the environment. Upon detailed analysis of the usage conditions at the customers' sites, it was discovered that the environment was located near a rail line in close proximity to a hot spring. This condition led to high levels of sulfur-containing gases. Detailed analyses were conducted to investigate whether this environment could be the primary cause of the premature failure, and the analysis yielded compelling evidence indicating that the hostile sulfur-containing gases are responsible for the rapid degradation of reliability and subsequent failure. Remarkably, the customers were not aware of such hostile environments, likely due to their lack of awareness regarding its impact on the products, and hence such environment was not made known to us. Aware of the possible hostile environment that the products will be exposed to, proactive steps are implemented including the specification of environmental conditions for usage, the selection of anti-sulphuration components, and the inclusion of protective coating on the circuit boards of the product.