Deformation Physics
Solid body interaction between mating surfaces determines the electrical and mechanical behavior of electrical connections under load. In printed circuit board assemblies, contact mechanics governs how test probes or connector pins establish physical contact with conductive pads or test points. The localized forces must deform the surface asperities on the conductive pad to establish a low resistance metal to metal contact.
Achieving this requires sufficient normal force to penetrate surface oxides and contaminant films without gouging the underlying copper trace.
Interconnection Quality
Electrical performance of a press fit pin or spring probe depends on the sustained elastic and plastic deformation of the mating materials. Improper contact mechanics can result in intermittent electrical opens or resistive paths when the assembly is subjected to operational vibration or thermal expansion. If the insertion force of a connector is too low, the normal force is insufficient to maintain the gas tight seal required to prevent oxidation of the terminal surfaces over time.
Conversely, excessive force can damage the plating, causing copper exposure and accelerating galvanic corrosion.
Inspection Protocol
Verification of contact interface integrity uses force displacement profiling during the connector insertion stage. Measurement systems record the resistance force against the insertion distance to identify premature terminal bending or incorrect pin alignment. Automated test equipment plots these measurements to ensure the system remains within the specified force limits.
