There are many customers who have bubbles when using the conformal paint. The reason for this phenomenon is generally due to the fact that the circuit board is not cleaned, not dried, and there is dust and moisture on the circuit board. If there are bubbles in the material coming out of the nozzle, factors such as coating process pressure, material viscosity, nozzle model, humidity, etc. need to be considered. If bubbles appear after passing through the furnace, please carefully adjust the furnace temperature curve and the route of the nozzle.

      If we pay attention to the following five points when using the three-proof paint, we can reduce the probability of air bubbles.

      1. Before using the three-proof paint, first remove the dust, moisture and oil on the surface of the object to be coated with the three-proof paint to ensure that no corrosive residues remain on the surface of the object, so as to make the PCB circuit board three. The anti-paint can adhere well to the circuit board, which is beneficial to give full play to the three-proof (moisture-proof, salt-fog, mold-proof) performance of the circuit board three-proof paint.

      2. When coating by brushing, the area of the three-proof paint on the PCB circuit board should be larger than the area occupied by the device, so as to ensure that the device can be fully covered.

      3. When brushing the three-proof paint of the PCB circuit board, try to ensure that the object to be brushed can be laid flat, and there should be no dew after the brushing is completed, so as to ensure the smoothness of the brushing, and no exposed places, and the thickness of the brushing According to different requirements, it is about 25~50 microns. If there are higher requirements, secondary coating can be carried out.

      4. If the coating is done by immersion, make sure that the object to be coated is immersed in the coating tank vertically (note that the connector cannot be immersed unless it is carefully covered), immerse it for about 1 minute, then slowly take it out and immerse it in Don't go too fast to avoid creating too many bubbles.

      5. After the coating is completed, the heating method can be used to accelerate the curing of the three-proof paint of the PCB circuit board. The heating temperature should not be too high, and it is good within 80 °C.