The role of the terminal insulator, that is, the plastic part is to fix the internal metal conductor to ensure that it maintains the correct position arrangement, and to insulate the contact part and the contact part, and the contact part and the plastic part are insulated from each other. Therefore, the insulation must have excellent technology, electrical properties and mechanical properties. Especially in recent years, with the wide application of high-density and miniaturization of connection terminals, the effective wall thickness of the insulator is getting thinner and thinner. These put forward more stringent requirements on insulator materials, forming mold accuracy and process.

Due to the presence of metal residues on the surface or inside of the plastic parts of the terminal terminals, surface dust, flux residues and other pollution and moisture, material precipitates and harmful gas adsorption films merge with the surface water film to form ionic conductive channels, moisture absorption, mold, plastic material aging For other reasons, it may cause short circuit, leakage, breakdown, and low insulation resistance of the terminal.

Through the above analysis of the reasons for poor insulation, we can know that the terminal insulator material and molding process largely determine the insulation of the product. Therefore, it is particularly important to control the raw material of the insulator and detect the resistance of the insulator molding.

In addition, the assembly and storage environment of the terminal products should be moisture-proof and dust-free, to ensure that the insulator is not contaminated to the greatest extent.