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As electronic products become more and more lightweight, compact and compact, consumers have higher requirements for on-board wiring harness, such as higher robustness, smaller size and higher transmission function.On-board harnessThe common place is the circuit, which is used for the board-to-board connection line on the circuit board, line-to-line or line-to-board connection line on the harness. In addition to electric circuits, other places can also be used, such as mechanical equipment, automobiles, aviation and other places that need connecting wires.

The important part of the on-board harness is naturally to contact local terminals and connect some equipment with similar or different functions to ensure that some components can operate smoothly or the current can flow smoothly, so that all equipment can operate. Most of the data of these terminals are different. Because the nature and function of the premise used are different, the material selection will also be different. Some need metal, some need plastic, some need liquid, and some need solid. In short, the selection of materials depends on the specific situation. It is very important to consider the use environment when selecting the coating of the vehicle harness terminal. It can be divided into three situations: for individual use, the common one is tin plating, because tin is cheap, but the quality of tin is soft. In order to ensure good contact, higher contact force is required, and the number of plugging and unplugging is relatively low, which can only play the role of simple maintenance anti-corrosion, and the working temperature is relatively low, The working temperature of brass or bronze tin plating can reach 110 ℃, and that of steel tin plating can reach 190 ℃. For high times of plugging, individual gold plating is required. For higher working temperatures, other coatings are required, such as nickel plating on red copper at 340 ℃ and nickel plating on brass or bronze at 250 ℃.

For the use of small signal and small contact force required by the firmness of on-board harness, gold plating is used individually, and the corrosion resistance of gold is also outstanding. Nickel plating is used as the bottom layer of gold plating, and most of steel contacts are nickel plated (copper must be plated first). The conductivity of palladium is worse than that of gold, and it is mostly used to replace gold electroplating in some limited areas. At present, the gold price continues to rise, and there are more and more products plated with palladium nickel alloy. Silver plated contacts have good conductivity, but silver is easy to oxidize, so it can only be used under special circumstances.