Voltage Boundary
Maximum permissible electrical resistance across a mated interconnect surface defines the integrity of a signal path during board operation. A contact resistance threshold determines when an oxide layer or mechanical deformation degrades connection performance beyond recovery. Engineers specify this limit during the design of high current connectors to prevent local heating and potential failure of the assembly.
Manufacturers apply this value during final continuity testing to confirm the reliability of every circuit point.
Measurement Protocol
Verification of this parameter relies on a four-wire Kelvin sensing method to eliminate lead wire impedance from the calculation. Direct current flows through the junction while the voltage drop across the interface indicates the total resistive load. If the computed resistance exceeds the predefined threshold, the interface fails the quality audit immediately.
Automated probe stations record these values across thousands of points on a single board to maintain statistical control over the production batch.
Operational Failure
Excessive resistance at a mating junction generates heat when current moves through the junction, which accelerates the growth of insulating films on the metal surface. Oxidation consumes the conductive material and further increases the electrical drop across the terminal. This feedback cycle leads to intermittent signal loss and eventual permanent interruption of the electronic function.
Total contact failure occurs when the material degradation becomes irreversible due to thermal damage.
