From the point of view of application, the function of the terminal should be: it is necessary to conduct the connection at the place where the contact part is connected, and the contact is reliable. Where the insulation part should not be conductive, it is necessary to insulate firmly. There are three common fatal fault modes of terminal:
1. Poor contact
The metal conductor inside the terminal is the central part of the terminal, which transmits the voltage, current or signal from the external wire or cable to the contact corresponding to its matching connector. Therefore, it is necessary for the contact to have excellent structure, stable and reliable contact force and good conductive function. Because of the unreasonable structural design of the contact, wrong material selection, unstable mold, out of tolerance of processing size, rough appearance, unreasonable surface treatment processes such as heat treatment and electroplating, improper assembly, poor storage and application environment and improper operation, poor contact will be formed at the contact parts and cooperation parts of the contact.
2. Poor insulation
The effect of the insulator is to make the contact adhere to the correct orientation, and insulate the contact from the contact and the shell. Therefore, it is necessary for the insulator to have excellent electrical function, mechanical function and process molding function. Especially with the wide use of high-density and miniaturized terminals, the useful wall thickness of the insulator becomes thinner and thinner. This puts forward more stringent requirements for insulation materials, injection mold accuracy and molding process. Because there are metal residues on the surface or inside of the insulator, external dust, flux and other pollution and moisture, organic material and harmful gas adsorption film and external water film blend to form ionic conductive channels, moisture absorption, mold growth, aging of insulating materials and other reasons, short circuit, leakage, breakdown and low insulation resistance will be formed.
3. Poor fixation
The insulator not only provides insulation effect, but also provides accurate centering and maintenance for the protruding contacts. Together, it also has the functions of installation, positioning, locking and fixing on the equipment. Poor fixation, the light one will affect the firm contact and cause instant power failure, and the serious one is product disintegration. Disassembly refers to the abnormal separation between the plug and the socket and between the pin and the jack caused by the unstable structure of the connection terminal due to the material, design, process and other reasons, which will cause the serious consequences of the interruption of the power transmission and signal control of the control system. Because of unreliable design, wrong material selection, improper selection of molding process, poor quality of heat treatment, mold, installation, welding and other processes, and improper installation, poor fixation will be formed. Cable terminal
In addition, poor appearance due to coating peeling, corrosion, bruise, plastic shell flash, crack, rough processing of contact parts, deformation and other reasons, poor interchangeability due to poor positioning and locking cooperation size, poor processing quality consistency, and excessive total separation force are also common and frequently occurring diseases. These faults can generally be found and eliminated in time during inspection and application.
