Product structure: such as screw anti-dropping, arc-shaped before and after splicing products, long digit deformation, shrinkage deformation caused by uneven wall thickness, etc. At present, there are several ways to prevent the screw from falling off: three ribs, hoop mouth, neck mouth and stamping. Due to the influence of technology and technology, there are not many ways to prevent the screw from falling off, but most of them are using the neck mouth anti dropping. The main reason for the deformation of the length of the splicing product combination is that the force of the two splicing falcons is unbalanced in the front, the bottom, the left and the right due to the unreasonable structure The stress and deformation direction of the splicing Falcon should be considered in the structural design. CTI parameters must meet the requirements in design, which directly affect whether the final product can pass the impulse withstand voltage and aging test. According to UL regulations, it is allowed to use no more than 25% recycled material and 75% new material after full mixing. Especially for some products that can withstand high current and high voltage, the use of recycled materials should be lower or not added. In the aspect of electroplating, the plating layer also directly affects the main factor of the terminal life. As far as gold plating and silver plating are concerned, the conductivity of silver is higher than that of gold, but its chemical stability is not as good as that of gold plating. However, the cost of gold plating is high. Only the products with acid environment or worse application environment are recommended to use electroplated gold. Moreover, local gold plating is applied to the contact part of the pressed sheet, which not only ensures the improvement of service performance, but also greatly reduces the product cost. In terms of hardware materials, the quality of the materials directly affects the electrical performance and connection performance of the terminal, which plays an important role in the electrical connection. The design of the terminal is an important factor to determine the quality of the terminal. Because the conductivity of the material directly affects the temperature rise and contact resistance, and the elasticity is related to the chemical elements, elastic modulus, hardness and tensile strength of the material. The higher the conductivity of the material is, the smaller the contact resistance is, the lower the temperature rise is. The relationship between the plug-in force and the contact resistance is a quadratic curve.