Meaning
Spring-loaded mechanical contactor used to establish a reliable but temporary electrical connection between two conductive surfaces. Every pogo pin consists of a hollow tube, a plunger and an internal spring that provides the necessary force to break through surface oxides. These components are frequently used in test fixtures and docking stations where a high number of mate and unmate cycles is expected.
Contact Force
Pressure exerted by the spring ensures that the plunger maintains stable contact with the target pad. The pogo pin must provide enough force to overcome contaminants on the surface without damaging the delicate plating of the device under test. This force is carefully balanced during the design of the pin to ensure electrical consistency over time.
If the spring is too weak, the contact resistance will fluctuate and lead to false test failures.
Lifecycle Durability
Number of times the plunger can be compressed before the spring fails or the plating wears off defines the useful life of the sensor. High quality pogo pin designs use gold plating on the internal and external surfaces to minimize wear and maintain low resistance. Regular cleaning and inspection are required to remove debris that can jam the plunger or increase the electrical noise.
In a high volume production line, these pins are considered consumable items that are replaced periodically.
Signal Performance
Internal resistance and inductance of the spring can affect the quality of high speed data signals. A pogo pin designed for radio frequency testing often has a shorter travel and specialized geometry to minimize parasitic effects. The path of the current through the pin is not a simple straight line, which can introduce timing jitter in digital circuits.
Advanced versions use coaxial structures or multiple contact points to improve the bandwidth of the connection.