The choice of connector materials for different application scenarios is also very different. The housing of the connector, as the main part of the entire connector, roughly determines the size and size of the connector.
Next, we will introduce several kinds of connector plastic materials, which have very important technical knowledge, whether it is for buyers, engineers, or business, they must learn technical knowledge.
1. Commonly used materials of connector insulators
Usually there are: PBT, NYLON, ABS, PC, LCP and other materials, but in principle, materials with better flame resistance are used.
A.PBT material:
Generally commonly used PBT material is added with 20-30% glass fiber, which has the ability of anti-cracking, anti-shock, anti-electricity, good wear resistance, low friction coefficient, good self-lubricating effect, good oil resistance and chemical resistance. It has good dielectric strength under high temperature and humidity. Its shrinkage rate is between 0.6%-3.0%, and its temperature resistance is about 230°C. Good formability and flame resistance. It is a commonly used compound for connector products.
B .NYLON66, NYLON6T
Nylon has good toughness, self-lubricity, chemical resistance and abrasion resistance. PA6T has better toughness than PA9T, and its heat distortion temperature is 290 degrees Celsius, which is very suitable for SMT connectors. PA46 products have high strength and good toughness, and are not prone to cracks.
C. ABS material
Has good impact toughness, oil resistance, abrasion resistance, easy molding, good rigidity, good rigidity, temperature resistance of about 100°C, and it is generally used for auxiliary products in connectors.
D, LCP
LCP, liquid crystal polymer, is a material with very good electrical insulation properties. It can maintain its electrical properties at 200 to 300 degrees Celsius without being affected, and can reach a temperature of 316 degrees Celsius when used intermittently.
In addition, LCP has very strong corrosion resistance, and will not be corrosive in 90% acid or 50% alkaline environment. LCP also has excellent thermal stability, heat resistance, and chemical resistance.
2. Selection principle
1. Good fluidity (such as LCP, nylon, etc., thin-walled products can be prepared)
2. High strength, good impact performance
3. High temperature resistance (especially SMT)
4. Excellent electrical properties (high resistance, low dielectric loss)
5. Short molding cycle (improve production efficiency and reduce costs)
6. If the performance meets the conditions, the price has an advantage
Three, the composition and performance of the connector contact
Bonding body material: The plug is made of metal bonding body material. Generally, brass is the main material. However, it is particularly required to have a very high number of insertions and removals, and phosphor bronze, beryllium copper, etc. can also be used for long life. The following is an introduction to the types and properties of copper in the current industry
1. Brass-an alloy of copper and zinc, the total color varies with the content of zinc.
A. Brass--for those with 25~35% zinc, it is most suitable for processing at room temperature.
B. Brass-35%~45% tin, most suitable for processing at room temperature. Copper plates and copper rods sold on the market belong to this category.
2. Bronze-an alloy of copper and tin. The color varies with the content of tin. Generally speaking, copper alloys other than brass are called bronze.
Phosphorous Bronze-Phosphorus in bronze has abrasion resistance, but too much phosphorus will make casting difficult. Its composition is tin 8~129% and phosphorus 0.5~1.5%...
3. Selection of contact material
The contact can be made of any of several alloys. The specific selection depends on the type of contact, the frequency of insertion and removal, and the electrical and environmental conditions of the connector. Some commonly used materials and their applications are as follows:
Brass-Although brass is a material with good electrical conductivity, it is prone to deformation and rapid fatigue after repeated bending. It is usually used as a fixed contact in a cheap connector, or as other metal parts in the connector. Connectors with brass contacts should not be used where excellent flexibility is required. Of course, due to its low cost, brass can still be used competently as contacts in many places.
Phosphor bronze-Phosphor bronze has higher hardness than brass, while maintaining longer-term elasticity. It is often used as a material for contacts whose working temperature is lower than 300°C. For most connectors with low mating frequency or normal bending of the contacts, the use of phosphor bronze can ensure good reliability.
Beryllium bronze-beryllium bronze has far better mechanical properties than brass or phosphor bronze. Beryllium bronze parts can be shaped and hardened after annealing, and can actually keep their shape permanently. It is also the most resistant material to mechanical fatigue. In applications that require frequent insertion and removal and high reliability, beryllium bronze is recommended.