Pogo Pin Contact Resistance Below 50m

Time：2025-08-28 Views：1 source:

Maintaining contact resistance below 50mΩ is a critical performance criterion for pogo pins, ensuring efficient electrical conduction in applications where signal integrity and power transfer are paramount. Contact resistance, the resistance at the interface between the pogo pin and its mating surface, is influenced by factors like material selection, plating quality, spring force, and surface finish.

To achieve sub-50mΩ resistance, manufacturers focus on optimizing the contact interface. High-conductivity materials are essential: the pin’s plunger is often made from brass (conductivity ~28% IACS) or copper alloys, plated with gold (conductivity ~73% IACS) or nickel-gold combinations. Gold plating, even in thin layers (0.1–0.5 μm), minimizes oxidation and ensures a low-resistance contact, as gold is highly resistant to tarnishing.

Spring force is another key factor. Adequate force (typically 50–200 grams) ensures intimate contact between the pin and the mating surface, breaking through any oxide layers or contaminants that could increase resistance. However, excessive force can cause wear, so engineers balance force with material hardness to maintain long-term performance.

Surface finish is critical: the plunger’s tip is often rounded or conical to concentrate pressure at a small contact point, reducing resistance. Precision machining ensures a smooth, burr-free surface, preventing micro-gaps that trap air or debris.

Testing to verify sub-50mΩ resistance involves using a four-wire resistance meter, which eliminates lead resistance from measurements. Pins are tested under various conditions (temperature, humidity, cycle count) to ensure resistance remains stable. Applications requiring such low resistance include high-speed data transmission (e.g., USB-C connectors), power delivery systems, and medical devices, where signal accuracy and energy efficiency are non-negotiable. By meeting this stringent standard, pogo pins ensure reliable, low-loss electrical connections in demanding environments.