The contact resistance of the RJ45 network connector PIN pin is mainly affected by factors such as contact material, vertical pressure, surface morphology, operating voltage, and current.

1. Contact material

The technical conditions for network connectors specify different contact resistance assessment indicators for the same specification plug-in contacts made of different materials. According to the general specification GJB101-86 for quick separation and environmental resistance electrical connectors, the contact resistance of plug-in contacts with a diameter of 1mm is ≤ 5m Ω for copper alloys and ≤ 15m Ω for iron alloys.

2. Vertical pressure on the surface of the contact surface

The surface vertical pressure of contact parts refers to the force generated by the surfaces in contact with each other and perpendicular to the contact surface. As the vertical pressure increases, the number and area of contact micro points also gradually increase, and at the same time, the contact micro points transition from elastic deformation to plastic deformation. Due to the gradual decrease in concentrated resistance, the contact resistance decreases.

The contact positive pressure mainly depends on the geometric shape and material properties of the contact part.

3. Surface morphology

The surface morphology includes the designed shape and the environmental state in which it is located. The contact surface may form a relatively loose surface film due to mechanical attachment and deposition of dust, rosin, oil stains, etc. on the contact surface. This surface film is prone to being embedded in micro pits on the contact surface due to the presence of particulate matter, which reduces the contact area, increases the contact resistance, and is extremely unstable. The second reason is that the fouling film formed by physical adsorption and chemical adsorption mainly involves chemical adsorption on the metal surface, which is generated along with electron migration after physical adsorption. Therefore, for some products with high reliability requirements, such as aerospace electrical connectors, clean assembly and production environment conditions, complete cleaning processes, and necessary structural sealing measures must be provided. The user unit must have good storage and operating environment conditions.

4. Using voltage

When the voltage reaches a certain threshold, the contact film layer will be broken down, causing a rapid decrease in contact resistance. However, due to the thermal effect accelerating the chemical reactions near the membrane layer, it has a certain repairing effect on the membrane layer. So the resistance value exhibits nonlinearity. Near the threshold voltage, small fluctuations in voltage drop can cause changes in current within a range of twenty or tens of times. Causing significant changes in contact resistance can lead to errors when testing and using contact components without understanding this situation.