The technique of using USB connector in harsh environment
In the selection of USB connectors, there are many factors to consider, including environmental parameters is one of the most important factors, including temperature, humidity, air pressure and so on. Under different environment conditions, the use of USB connectors is also different, below to introduce some extreme environment of the use of skills.
1. High Temperature environment
The metal material and insulating material of the USB connector determine the working ambient temperature of the connector. The high temperature will destroy the edge material, cause the insulation resistance and the pressure resistance performance to reduce, to the metal high temperature may cause the contact to lose the elasticity, the accelerated oxidation and the occurrence coating metamorphism. The usual ambient temperature may require higher -40~80℃ special occasions.
2. Humid environment
The relative humidity is more than 80%, which causes the electric shock to wear. Humid environment caused by water vapor absorption and diffusion of the surface of the insulator, easy to reduce the insulation resistance to below the mω level, long-term in a high humidity environment, will cause physical deformation, decomposition, escape of the formation, the formation of respiratory effects and electrolysis, corrosion and crack. Especially in the external USB connectors, often to consider the humid, water infiltration and pollution of environmental conditions, in this case should choose a sealed connector.
3, the temperature of the environment
The humidity test is to simulate the use of USB connectors in the cold environment to the actual use of the warm environment, or simulation of space vehicles, detectors, the environment temperature changes dramatically. The temperature may cause cracks or layers of insulating material.
4, thin air environment
In the rarefied air, the plastic emits the gas pollution contact pair, and causes the corona to produce the tendency to increase, the pressure resistance performance drops, causes the circuit to short-circuit the fault. When the high altitude reaches a certain value, the plastic performance becomes worse. Therefore, when using unsealed connectors at high altitude, the amount must be reduced.
5. Corrosive environment
According to the use of USB connectors in different corrosive environment, the selection of the corresponding metal, plastic, coating structure of connectors, such as in the salt fog environment for the use of connectors, if there is no anti-corrosion metal surface, will cause rapid deterioration in performance. In a SO2 environment with a fairly high concentration, it is not advisable to use a connector with a silver plated contact pair. In hot and humid areas, mold is also an important problem.
Netizens asked: When designing electronic products, is it necessary to use High-quality USB connectors?
Experts answer: This netizen refers to the problem is a lot of USB system designers often encounter, is also a misunderstanding, because in the design often underestimate the importance of connectors and use cheap and poor quality connectors. While this may seem like a cost saving, its subsequent maintenance costs are considerable. Low-quality connectors can cause USB system not normal operation, product recall, product liability cases, circuit board damage, rework and maintenance, will eventually lead to loss of users, I believe this is not what enterprises want to see. Therefore, when designing USB products, do not underestimate the importance of connectors, you should choose a high-quality and appropriate USB connectors.