Meaning
Spring-loaded contact element designed to make electrical connections in test fixtures with center spacing below 0.4 millimeters. The fine pitch pogo pin consists of a plunger and barrel along with an internal spring to maintain pressure against the target. These components are used in high-density sockets for wafer-level or package testing.
Mechanical Construction
Miniature dimensions require the use of specialized alloys to ensure the barrel does not burst under spring pressure. Each fine pitch pogo pin is assembled under a microscope to ensure the plunger moves freely without binding. The internal spring must be strong enough to break through surface oxides but small enough to fit within the narrow barrel.
Contact Resistance
Small surface areas at the tip increase the electrical resistance of the connection. A fine pitch pogo pin is typically plated with gold or rhodium to minimize this opposition and prevent corrosion. Regular cleaning of the tips is necessary to remove solder buildup that occurs during high-volume testing.
Cycle Durability
Mechanical wear limits the lifespan of the spring and the plunger interface. The fine pitch pogo pin is rated for a specific number of compressions before the spring force drops below the required threshold. Once the force degrades, the pin must be replaced to ensure consistent electrical contact.
