the basic functions of connectors

Connectors have three basic functions that is mechanical properties, electric properties and environmental properties.

With regard to connectivity, Insertion and withdrawal force are very important mechanical properties. As far as the use is concerned, the insertion force should be small, so we have LIF and ZIF. On the contrary, if the withdrawal force were too small, it would weaken the contacts.

Another mechanical property is the mechanical endurance of connector. In fact, mechanical endurance is a kind of durability index, which is called mechanized operation in GB5095. Each insertion and withdraw is a circle. The basis for the judgment is whether connector are able to complete the connectivity after a circle of insertion and withdrawal forces.

The insertion and withdrawal force  and mechanical endurance of connector is related to the structure of contacts, the quality of the contacts’ coating and the Size precision of the contacts.

electric property

Electric property mainly consists of contact resistance, insulation resistance, and dielectric strength.

The high quality connector is of low and stable contact resistance. Contact resistance ranges from one milliohm to tens of milliohm.

Insulation resistance is used to measure insulating properties between contacts and jackets, which ranges from hundreds of megohm to thousands of megohm.

Dielectric strength explains the tolerance of rated voltage between contacts and jackets, which depends on the circuit gap and the insulating material used.

Electric current is influenced by the  n connector and wire at the terminal.

As for RF coaxial connector, there are characteristic impedance , insertion loss, reflection coefficient, voltage standing-wave ratio and other electric index. With the development of digital technique, there comes out a new kind of high speed signal connector connecting and sending high speed digital pulse signal. At the same time, there comes out some new electric index such as cross-talk, delay, skew and so on.

environmental properties

Common environmental properties consist of thermostability, moisture-proof and Salt corrosion Resistance  .