Meaning
Mechanical pressure exerted at the interface of two mating conductive surfaces determines the electrical resistance and stability of the connection. Adequate contact force is required to break through surface oxides and contaminants to establish a low resistance metal to metal interface. This parameter governs the reliability of board to board connectors and test spring probes.
Spring Deflection
Compression of internal spring mechanisms or flexible beams generates the necessary pressure within the connector housing. The contact force increases with greater displacement until the material reaches its yield point or the connector is fully seated. Designing for the proper deflection range prevents both intermittent electrical opens and mechanical damage to the mating pads.
Interface Resistance
Measurement of the contact resistance under varying loads demonstrates how the electrical path behaves during physical vibration or thermal cycling. As the contact force decreases, the micro contact points on the surface separate, which raises the resistance and generates localized heat. This thermal rise can lead to accelerated oxidation and eventual connector failure.
Connector Assessment
Evaluation of mating cycles determines how the spring materials retain their elasticity over the lifetime of the product. Test fixtures measure the contact force at the start and end of life simulations to verify that the connector holds its rating. These results are documented in the component datasheet to assist integration engineers in selecting the right component for harsh environments.
