Functional Test Fixtures Owned by the Factory or the Buyer
Buyer-owned test fixtures require explicit PO line items, complete source files, and calibrated limit audits to prevent factory lock-in.
Pogo Pin Wear
Tip Degradation
Mechanical fixture wear inside automated test equipment defines the physical breakdown of spring loaded electrical interfaces during repeated board contact cycles. Pogo pin wear degrades electrical continuity between test probes and printed circuit board test pads through repeated mechanical friction and plating abrasion. Automated testers measure this degradation by tracking rising contact resistance across successive insertions until values exceed acceptable production thresholds.
The boundary condition rests where probe tip deformation alters compliance force enough to cause false open circuit failures during bare board or populated assembly testing.
Spring Fatigue
Continuous compression cycles alter the elastic limit of the internal coil spring inside the probe barrel. Material fatigue reduces spring force and allows high resistance oxidation layers to form between the plunger and the socket wall. Automated handlers catch this mechanical failure when test cycle times drift because sluggish plungers fail to make instant electrical contact upon touchdown.
Test engineers replace degraded probes before contact resistance jumps high enough to halt high volume printed circuit board manufacturing lines.
Plating Loss
Base metal exposure occurs when gold plating wears off the plunger tip through continuous sliding friction against copper test pads. Bare brass or beryllium copper oxidizes rapidly in ambient factory air and creates unstable electrical connections that corrupt test measurements. Automatic test equipment diagnostic routines flag this transition when calibration checks reveal erratic resistance readings during routine fixture verification.
Replacements restore proper contact resistance values and maintain measurement integrity across subsequent manufacturing runs.
Flying Probe against a Bed of Nails at Real Volumes
Flying probe testing saves tooling costs on runs under 11,000 units, while bed of nails fixtures deliver superior cycle speeds and lower per-unit cost at scale.