The purpose of the plating of the pin header

Speaking of the pin header, as a component practitioner, how much do you know? Do you know what effect the plating of the pin headers has? The following Konnra Electronics engineers will introduce you to the role of the pin plating. I hope that through our explanation, you will have a deeper understanding of the plating effect of the row of pins.

The optimization of electrical performance can be considered from the control of the film on the surface of the contact plating that is already present and about to be formed. A major requirement for the electrical performance of the pin headers is to establish and maintain a stable pin header impedance. To achieve this, a metal contact interface is required to provide such inherent stability. Establishing such a contact interface requires that the surface film be able to avoid or split during contact engagement. These two different options clarify the difference between precious metals or rare metals and ordinary metals.
To varying degrees, precious metal coatings (such as gold, palladium and their alloys) are essentially free of surface film. The metal contact that creates the interface for these coatings is relatively simple because it only requires movement of the accompanying surfaces of the contact surfaces during mating. Usually this is easy to implement. In order to maintain the stability of the contact interface impedance, the design of the pin header should be designed to maintain the precious metality of the contact surface to prevent external factors such as contaminants, diffusion of the substrate metal, and contact wear.

Ordinary metal coatings, especially tin or tin alloys, are naturally covered with an oxide film. The role of the tin contact coating is because the oxide is easily destroyed during the bonding, so that the metal contact is easily established. The requirement of the pin header design is to ensure that the oxide film breaks when the pin header is mated, and that the contact interface is no longer oxidized during the validity period of the electric connector. Reoxidation corrosion, in wear and corrosion, is the main performance degradation mechanism of tin contact coating. The silver contact plating of the pin header is preferably treated as a common metal plating because the coating is susceptible to corrosion by sulfides and chlorides. The nickel plating is usually regarded as a common metal because of the formation of the gas valve.