PCB Technical - How to judge the quality of PCB board tri-proof paint after salt spray test

How to judge the quality of PCB board tri-proof paint after salt spray test

PCB board factory:Salt spray corrosion is a common and very destructive atmospheric corrosion, especially for PCB board three-proof paints used in marine and saline-alkali environments. Salt spray corrosion verification is especially important. Many people may not know how to judge whether the product is qualified after the salt spray test of the PCB board three-proof paint. Today I will share some judgment methods with you. The specific operations are as follows:

Three anti-paint for PCB board

1. Rating method

After the salt spray test of the three-proof paint of the PCB board is completed, the salt crystals on the surface of the PCB board are washed with flowing water. Under a good lighting environment, carefully observe the corrosion degree of the product surface with the naked eye, according to the corrosion degree or corrosion of the product surface The area is graded. Standard comparison samples can be prepared at the same time, so that the corrosion grade evaluation will be more accurate.

Two, weighing method

The principle of this method is very simple, that is, weigh the test sample before the experiment, and weigh the sample after the test. According to the loss between the weight of the test sample before and after the experiment, determine whether the product is qualified. The specific operation is as follows: The coated PCB board is accurately weighed, and the weighing data should be recorded (accurate to the milligram). After the salt spray test of the PCB board three-proof paint is completed, the salt crystals on the PCB board surface are also washed with flowing water Then use distilled water for cleaning. After cleaning, put it in a high-temperature drying box for drying (the temperature of the high-temperature drying box is 105-110 degree Celsius, and pay attention to avoid the PCB board from being contaminated in the drying box). Weigh after drying and record the weighing data. Finally, compare the data of the two weighings before and after the experiment. Products with a weight loss of more than 7.5 mg are judged as unqualified.

3. Visual inspection

After the salt spray test of the PCB board three-proof paint, a layer of white salt crystals will precipitate on the surface, which will disappear naturally after washing with water. At this time, observe carefully and compare with the standard sample. If the surface of the PCB board is smooth and flat, If there is no surface defects such as damage, wrinkles, etc., the product can be judged as qualified.

The above are some methods of how to judge the quality of the PCB board tri-proof paint after the salt spray test.