General principles of terminal design


Terminals are one of the basic components of electrical […]

Terminals are one of the basic components of electrical connection. They play a decisive role in the electrical connection. The design of the terminal is one of the important factors that determine the quality of the terminal. The basic general principles to be considered when designing the terminal are briefly introduced. .

1. Product standards: Terminals belong to the category of connectors, so when designing terminal blocks, reference should be made to IEC, UL, CSA, VDE, TU, GB and other international and domestic standards for electrical connections, as well as some industry standards, such as JB , GJB, etc. In China, the universal terminal standard is GB14048.7 / 8.
2. Material selection: The performance of the material directly affects the performance of the entire product and is the key to design. Take the general PA66 as an example, this is the most widely used plastic material selected by most manufacturers. This material better meets UL94, V-0 flame retardant rating, Ningbo Supu Electronics is using this as a plastic material. At this time, the CTI parameters must meet the requirements when designing, which directly affects whether the final product can pass the tests of impact withstand voltage and aging resistance. According to UL regulations, no more than 25% of recycled materials can be used together with 75% of new materials after being fully mixed and mixed, especially for some products that can withstand high current and high voltage, the use of recycled materials should be lower or not. Fill in.

In terms of hardware materials, for conductive parts and components that must be flexible, such as the pressing piece of the terminal, the quality of the material directly affects the electrical and connection performance of the terminal, because the conductivity of the material directly affects the temperature And contact resistance. The elasticity is related to the chemical elements, elastic modulus, hardness, and tensile strength of the material. The greater the electrical conductivity of the material, the smaller the contact resistance, the lower the temperature rise, and the lower the insertion force and contact resistance. The relationship of the quadratic curve.

In terms of electroplating, the plating film also directly affects the main factors of connector life. For gold plating and silver plating, silver has higher conductivity than gold, but its chemical stability is not as good as gold, and the resulting film resistance is much greater than gold plating. However, the cost of gold plating is high, and it is only recommended for use in acidic environments or Electroplated gold is only used for products in more severe application environments, and local gold plating is applied to the contact parts of the tablet, which not only ensures improved performance, but also greatly reduces product costs.

3. Product structure: For example, the screws are prevented from falling, the spliced ​​products are curved before and after, long-digit deformation, etc., and shrinkage deformation caused by uneven wall thickness. There are currently several ways to prevent the fall of screws: three ribs, the hoop, the neck, and stamping. Due to the influence of technology, not many necks are used, and most of them are used. Prevent it. The deformation problem of the growth digits of the splicing product combination is also the main reason for the unbalanced structure of the two splices. The forces on the two splices are unbalanced. Deformation direction. The insertion force of the plug-in terminal is related to the material, plating, structure, and the industry to which it is applied. It is an important mechanical performance requirement of the connector industry. The insertion force must be stable, the contact resistance must be small, and it must be able to meet a certain life and fatigue, so the requirements for the metal shrapnel material are high. For high-performance terminal blocks, the industry uses imported high-conductivity and highly elastic materials such as phosphor bronze.

4. Mold: The main surface of the terminal is mainly plastic mold and metal continuous mold. The quality of mold design and manufacturing has a great impact on the terminal parts. In addition to providing standard products, Ningbo Supu Electronics also has a professional R & D team to provide customers with ODM / OEM services, effectively solving personalized solutions for electrical connection products proposed by customers-terminal blocks, connectors, etc.

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