The connector is an indispensable part of electronic equipment. It builds a bridge of communication between the blocked or isolated circuits in the circuit, so that the current can flow and the circuit can achieve the intended function. The form and structure of connector array pins are ever-changing. With different application objects, frequencies, power and application environments, there are various types of connectors. Although there are many kinds of connectors, the basic performance can be divided into three categories: mechanical performance, electrical performance and environmental performance.

As far as the function of connector is concerned, the plugging force is an important mechanical property. Insertion and pull-out force is divided into insertion force and pull-out force (pull-out force is also called separation force), and their requirements are different. There are provisions on maximum insertion force and minimum separation force in the relevant standards, which shows that from the perspective of use, the insertion force is small (so there are structures with low insertion force LIF and no insertion force ZIF), and if the separation force is too small, the contact reliability will be affected.

Another important mechanical property is the mechanical life of the connector. Mechanical life is actually a durability index, which is called mechanical operation in the national standard GB5095. It takes one insertion and one extraction as a cycle, and takes whether the connector array can normally complete its connection function (such as contact resistance value) after the specified insertion and extraction cycle as the judgment basis. The insertion and removal force and mechanical life of the connector are related to the contact structure (positive pressure), the coating quality of the contact part (sliding friction coefficient) and the dimensional accuracy (alignment) of the contact arrangement.

Vibration and impact performance: Vibration and impact resistance is an important performance of electronic connectors, especially important in special application environments such as aviation and aerospace, railway and road transportation. It is an important indicator for testing the robustness of mechanical structure and electrical contact reliability of electrical connectors. There are clear provisions in relevant test methods. Peak acceleration, duration, impact pulse waveform and interruption time of electrical continuity shall be specified in the impact test.

Contact resistance: high-quality electrical connectors should have low and stable contact resistance. The contact resistance of the connector varies from a few milliohms to tens of milliohms. The factors affecting the contact resistance include: the resistivity of the contact surface material, contact pressure, contact area, contact shape, surface condition (relative cleanliness, roughness and hardness), current, open circuit voltage at the contact when the current is cut off, temperature and thermal conductivity of the wire.

Dielectric strength, or voltage resistance and dielectric withstand voltage, is the ability to withstand rated test voltage between connector contacts or between contacts and shell. The measurement method is to apply a test voltage higher than the working voltage between the contacts of the connector and between the contact and the shell for a specified time to determine the correctness of the insulating material, insulation spacing and insulation structure, check the defects of the parts, and assess the ability of the electrical connector array to withstand the transient over-voltage caused by opening, closing, surge and similar phenomena

The insulation resistance is an index to measure the insulation performance between the contacts of electrical connectors and between the contacts and the shell, and its magnitude varies from hundreds of megohms to thousands of megohms. It is determined by the dielectric capacity of the dielectric, and the greater the insulation resistance, the better. The insulation resistance cannot be equated with the withstand voltage. Because insulation materials are mixed or synthesized by different materials, their insulation resistance is naturally different. Therefore, the measurement of insulation resistance cannot completely replace the measurement of cleanliness or nondestructive degree.