What are Pogo Pins (Spring-Loaded Pins)?
Meet the Connector: Pogo Pins (Spring-loaded pins)
Pogo pins, also called spring-loaded pins, are electrical connector mechanisms known for their durability and their ability to provide and maintain an electrical connection that is resilient to mechanical shock and vibration. They are widely used in a variety of electronic applications and in the test industry.
The pogo pin is so named because the pin resembles a pogo stick. Although often used as a generic term, pogo pin is a registered trademark of Everett Charles Technologies (ECT).
Its unique construction has an integrated spring that applies a constant force against the back of the mating receptacle or contact plate. This prevents movement that could result in an intermittent connection.
To complete the connection path, the mating receptacle that the spring-loaded pin engages, called a target or land, consists of a flat or concave metal surface. The target has no moving parts. It may be a plated area of a printed circuit board or a separate component in the connector assembly.
The turning and spinning fabrication process does not require a mold, which means spring-loaded pins can be produced in small quantities and at a lower cost than other contacts.
The pin construction includes a plunger, a barrel, and a spring. The spring is compressed and the plunger moves inside the barrel when force is applied. The barrel holds the plunger and prevents the spring from pushing it out when the pin is not locked in place. A slight gap between the plunger and the barrel allows the pin to move easily but can allow vibration to cause momentary disconnections. To avoid this and maintain continuous connection, the plunger typically has a slight tilt.
Manufacturers often develop proprietary variations of the interface. Sometimes a ball is added between the plunger and spring for greater stability and better performance.
- Materials Brass or copper are commonly used as the base material for the plunger and barrel of spring-loaded pins, with a thin layer of nickel applied to the surface. Gold plating improves the durability and contact resistance. The springs are usually made of spring steel or copper alloys.
- Connector arrangement Spring-loaded pins are typically arranged in a dense array. In automatic test equipment, a “bed of nails” configuration facilitates the rapid and reliable connection of devices under test (DUTs). In high-performance applications, the arrangement must allow high reliability through many mating/unmating cycles and high-fidelity transmission of electrical signals. In matched impedance circuits, the pins may be arranged with one signal-carrying pin surrounded by grounded pins.
- Magnets may be added to improve the strength and reliability of the connection. This is done in consumer electronics and high-frequency data transfer applications.
Markets, Sectors, and Applications
Spring-loaded pins are used in many modern electronic applications and in the electronics testing industry. They are used with board-to-board connectors, ingress protected connectors (for consumer devices such as smart watches, or rugged computers), laptop battery terminals, laptop docks and chargers, high-frequency connectors (antennas), as well as for PCB testing, IC testing, and battery testing.