Three Anti-paint Spraying Steps
The first step: clean the board surface, keep the board surface free of oily dust (mainly the flux component in the solder remaining in the soldering process, because it is mainly acidic substances that will affect the durability of the components and the three-proof paint and the board Surface adhesion,
The second step: drying, the cleaning agent and water should be dried to ensure the dryness of the board.
The third step: mix the three-proof paint according to the data provided by the manufacturer of the three-proof paint, prepare the appropriate viscosity of the three-proof paint, it is recommended to adjust the viscosity to 15-18 seconds in a suitable ratio, stir evenly, and then stand still After 3-5 minutes to let the bubbles disappear completely, you can put it into the spray gun and spray it. If you use a brush, it is recommended to buy a soft wool brush. Brush marks appear in the back, the surface of the paint film is not smooth, which will affect the appearance, and if the pig hair brush is used too hard during construction, it will generate bubbles)
Step 4: Spraying, the three-proof paint is filtered with 200 mesh gauze and poured into the spray can. Adjust the air pressure and spray shape of the spray gun. If the air pressure is too low, the sprayed paint film will have small pits and special holes. When the viscosity of the paint is higher, it is similar to the surface of orange peel (the same appearance as orange peel will appear when the board surface is oily). When the air pressure is too high, the conformal paint will be blown away by air pressure after spraying on the surface When the paint comes, piles of paint will appear, and sag will appear during the drying process. It is recommended to adjust the spray shape of the spray gun to a fan shape, and move the spray gun at a uniform speed at an angle of 45° to the board surface to spray evenly on the board surface. After spraying the first gun, go back to the second gun to make the second gun paint Press the paint film of the first gun, and so on until all the surface of the board is sprayed, so as to ensure that the paint film is even and does not leak. The speed of the spray gun should not be too fast. According to the data of the three-proof paint, ensure that the paint film can have a thickness of at least 50 microns.
Step 5: Bake. After spraying the surface of the board, enter it into the baking box for baking. Set the curve baking temperature according to the data provided by the three-proof paint manufacturer. If the three-proof paint is self-drying, if it is vertical baking If it is a box, it is recommended to let it stand outside for 3-5 minutes and then enter it in an oven that does not exceed 80 degrees and bake for 5-10 minutes. If it is a tunnel furnace, it is recommended that the front area is 60 degrees, the middle area is 80 degrees, and the rear area is 70 degrees. Set it like this. If the sprayed board surface is directly baked at high temperature, the surface paint film will dry faster than the paint inside, which is equivalent to a layer of film wrapping the bottom paint inside. When the solvent of the bottom layer of the paint needs to be volatilized during the drying process, it will bulge through the surface film and form a lot of pores and bubbles.
Step 6: Check the board and take the board out of the baking oven to check whether there are any leaking bubbles. If the paint film on the surface of the board is uniform and complete without bubbles, it is qualified.
Baking temperature of conformal paint
At room temperature, 10 minutes of surface drying, 24 hours of curing, if you want to be faster, you can bake at 60 degrees for 30 minutes, which can meet the curing requirements. If you want a good quality three-proof paint, like Mintong organic silicon three-proof paint, you need to bake it at 80 temperature for half an hour to fully cure.
Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.
