1. Contact pressure

Contact pressure is not only the main factor affecting contact resistance, but also the important factor controlling the pull-out force. It is mainly affected by material properties, processing technology, contact deformation and so on. The better the elasticity of the material, the greater the elastic force produced. At the same time, the state of the material also affects the contact pressure. Soft state materials have low tensile strength but high elongation. When the shape of the contact parts is complex, the material is usually annealed first to improve the formability of the material. After finishing the processing, temper again to improve the elasticity of the contact parts, so that the shape of the contact parts can be designed to be ever-changing, but a good design should satisfy other properties at the same time, also ensure the contact pressure of the contact parts.

2. Number of contacts

Contacts ensure the connection of connector signal and power supply, and are also the main factors affecting pull-out force. The more the number of contacts, the greater the pull-out force of connectors, especially the number of high-frequency contacts. For example, for a connector, the pull-out force of 8 Therefore, the number of connector contacts, especially the number of high-frequency contacts, directly affects the pull-out force.

3. Matching Error of Contact Parts

Due to the assembly error and manufacturing error of connectors, the contact parts are prone to the phenomenon of pin skew during the insertion process, and there will be additional extrusion force between pin and the wall of the pin. On the one hand, it will cause the increase of the insertion force, on the other hand, there may be contact fracture, pin shrinkage, fatigue damage and other phenomena, which seriously affects the life of connectors. When the above three important factors affecting the pull-out force are determined, it becomes the focus of our research to minimize the fitting error of the contact parts as much as possible.

4. Surface friction coefficient

Because the connector will be frequently inserted and separated in the use process, the plugging force has become one of the important factors affecting the reliability of the connector. The insertion force of the connector can be considered as friction force, and the magnitude of friction force is directly related to the positive pressure and friction coefficient between the contact surfaces. The factors affecting the friction coefficient of contact parts include contact materials, surface roughness, surface treatment and so on. Large surface roughness will increase the insertion force of connectors on the one hand, and the wear of contacts on the other hand, which will affect the insertion loss of connectors. In addition, the large surface friction coefficient will also affect the life of the contact parts. Therefore, relevant measures should be taken to minimize the roughness of the contact parts.