Corrosion Forms of Pogo Pin Connector Pins and Jacks

Time：2025-09-26 Views：1 source:

Pogo Pin connectors, with their exposed metal surfaces and frequent mating cycles, are susceptible to various forms of corrosion that can degrade electrical performance and shorten service life. Understanding these corrosion mechanisms is crucial for selecting appropriate materials and protective measures.

Galvanic corrosion is one of the most common forms, occurring when two dissimilar metals in the connector (e.g., the gold-plated pin and the copper-alloy jack) are in contact in the presence of an electrolyte (such as moisture, sweat, or industrial fluids). This creates a galvanic cell, where the less noble metal (copper) acts as an anode and corrodes preferentially. Signs include pitting or etching on the copper surface, which increases contact resistance. To mitigate this, designers often use metals with similar electrochemical potentials or ensure uniform plating (e.g., gold plating on both pin and jack) to prevent galvanic cells from forming.

Atmospheric corrosion, caused by exposure to oxygen, humidity, and pollutants (e.g., sulfur dioxide in industrial areas or salt in marine environments), affects both pins and jacks. Copper alloys form a layer of copper oxide (CuO) or copper sulfate (in polluted environments), which is porous and allows further corrosion. This layer can increase contact resistance and, in severe cases, block the mating interface. Protective platings like nickel (as a barrier layer) and gold (as a noble metal) act as shields, preventing direct contact between the copper and the atmosphere. Regular cleaning and sealing of connectors in harsh environments also reduce atmospheric corrosion.

Fretting corrosion occurs at the contact interface during micro-movements between the pin and jack, often caused by vibrations or thermal cycling. These small movements wear away the protective plating, exposing the underlying metal, which then oxidizes. The oxide particles (e.g., copper oxide) act as abrasives, accelerating wear and creating insulating layers that disrupt electrical contact. This is common in automotive or aerospace applications with high vibration levels. Using lubricants (e.g., dry film lubricants) or increasing contact pressure to minimize micro-movements can reduce fretting corrosion. Materials with high wear resistance, such as beryllium copper with hard gold plating, also slow down this process.

Chemical corrosion is triggered by exposure to aggressive substances like acids, alkalis, or solvents. In industrial settings, connectors may come into contact with cleaning agents or process fluids, which can dissolve plating or attack the base metal. For example, sulfuric acid fumes can react with copper to form soluble copper sulfate, leading to rapid corrosion. Chemical-resistant platings (e.g., palladium or rhodium) and housing materials (e.g., chemical-resistant plastics) provide protection. In extreme cases, hermetically sealed connectors prevent chemical ingress entirely.