What are the three temptations?
Electronic devices are very sensitive to environmental conditions. In particular, environmental factors such as humidity, salt spray and mould are more important. The so-called three tests refer to the resistance to moisture, salt and the resistance of electronic equipment. With the increase in requirements for the three tests of electronic devices, the problems exposed to electronic devices are increasing. Some products have difficulty withstanding heat, salt spray and mould tests. There is even a clear damage to the material, coating and insulation, as well as a significant drop in electrical performance. This article mainly describes water protection in all three tests.
Types of Water absorption system
There are four types of water absorption:
1)Dissemination
2)Absorption
3)Adsorption
4)Condensation
Diffusion and absorption cause water droplets to penetrate the material, thereby reducing the material’s electrical resistance. The bond between certain non-metal molecules is lower than the bond between water molecules. When water droplets enter the material, they melt into the material causing the material to change and begin to expand. Adsorption and condensation make a film of water on the surface of the material, which reduces the surface resistance of the material.
Four types of hygroscopic processes can occur at the same time, and be one or two of them. The process of absorbing water in this way is called direct water attack. It is also the easiest way to get water.
Breathing process
In addition, there is another way to get water, the “energy” method. It refers to the process of the introduction of water vapour into the protective layer, bags, pipes and bodies that are closed incorrectly under conditions of temperature changes and certain atmospheric pressures. “Breathing” is a slow process that is not visible in a short period of time. For the most demanding brand, the “energy” effect cannot be ignored.
Liquid water
Water not only destroys the electrical components, but also reduces the insulation resistance of the insulation material and the wood, makes the tangent of the dielectric loss angle, and reduces the insulation performance. In severe cases, there will be interruptions or even short circuits. At the same time, humidity also provides good conditions for mould growth. The skin is wet and can form a short circuit when it spreads over the cover. In addition, it will cause damage to metal and electronic equipment.
Quality control
The three components of evidence quality management include:
Structural and structural design to prevent corrosion
Qualified production process
Three strong evidence acceptance tests
The links above are important. The heart of the three quality tests is to evaluate the ability of electronic products to resist corrosion in humid temperatures, industrial air and salt spray. In this process, three proof acceptance tests refer to environmental simulation tests performed in an environmental test chamber. These tests make it possible to measure the effectiveness of the three tests. In addition, the test cycle can be shortened.
Discovery methods
In general, testing methods to determine the quality of the three proofs of electronic products include:
Artificial acceleration test
Natural weather forecast
The built-in acceleration test has a short test time, and the test results are very different from the real situation.
Also called artificial acceleration test. The most commonly used acceleration tests for electronic products are: humidity test, salt spray test and mould test. In fact, many manufacturers use humidity labs, salt labs and other facilities to test their products.
Temperature humidity test
Humidity tests are often used to determine the reliability of using and storing electronic products under conditions of temperature fluctuations and condensation on the product. It can determine changes in the electrical components and components of electronic products. Furthermore, it can also be used to determine the ability of a material to resist corrosion.
Conclusion
Triple evidence is not just a matter of process safety; they include all aspects of design, process, manufacturing and control. The types of testing methods and testing standards used in this process are also an important part of the three-problem electronic equipment.
