Meaning
Electrical opposition encountered at the physical junction where a spring-loaded test probe meets a conductive pad on a printed circuit board. Minimizing pogo pin contact resistance is necessary for accurate measurements of voltage and current in high-performance electronics. This value is typically measured in milliohms and changes based on the force of the spring and the cleanliness of the contact tip.
Force Application
Pressure from the internal spring ensures that the plunger maintains a constant connection despite vibrations or small movements. If the pogo pin contact resistance is too high, the resulting voltage drop can cause the test software to report a failure that does not exist in the product. Optimal force levels balance the need for a good electrical connection with the risk of damaging the surface of the circuit board or the sensitive gold plating.
Contamination Effect
Dust and solder flux residue can accumulate on the probe tips during the course of a production shift. This debris increases the pogo pin contact resistance and leads to inconsistent test results across different units. Regular cleaning cycles using air or specialized brushes help maintain the conductivity of the interface.
Degradation Limit
Metal fatigue and plating wear eventually cause the probe to lose its effectiveness after a specific number of cycles. When the value exceeds the limit defined in the test plan, the probe must be replaced.
