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中文The essence of “three-proof” in electronic processing is to apply a layer of protective film on the protected surface. The protective effect is related to the coating method and coating process. Spraying basically belongs to the protection of the PCBA surface, while dipping can protect the components. Conformal coating is a specially formulated coating used to protect circuit boards and related equipment from environmental erosion, thereby improving and extending their service life and ensuring safety and reliability in use.
“Three-proof” process design requirements:
(1) Protection of components: Dip or potting of transformers, coils, etc.; solid protective film protection of docking plug-ins; special treatment of components.
(2) Coating thickness: film thickness is between 0.005mm-0.15mm, dry film thickness is 25μm-40μm.
(3) Surface drying: ventilate for 20-30 minutes after coating to dry the surface. It can be used after drying, but avoid collision during this process.
(4) Paint curing: Curing takes 8-16 hours at room temperature.
(5) Second drying: After paint curing, secondary drying can be carried out to ensure the reliability of product thickness.
(6) The minimum spacing between painted and unpainted components in PCBA is 3mm.
“Three-proof” mainly improves the anti-corrosion level of PCB – covering the exposed Cu, isolating the corrosive gas and moisture in the air. As long as the conditions of sulfidation, electromigration, electrochemical corrosion and chemical corrosion can be destroyed, the purpose can be achieved. Conformal coating spraying can provide various protections for circuit boards: moisture-proof, mildew-proof, dust-proof, insulation, minimize the growth of dendrites, release stress, etc.
The core of the “three-proof” process: three-proof paint, process and paint film thickness. The effect of “three-proof” depends on the thickness of the paint film. “Three-proof” only delays moisture absorption and cannot completely prevent moisture. If waterproof and dustproof are required, potting process should be used.
Ucreate has been focusing on PCB manufacturing, component mounting and programming test for more than 19 years, providing SMT mounting, THT plug-in, conformal coating technology and one-stop PCB assembly and processing for various electronic products such as consumer electronics, medical equipment, automotive electronics, new energy equipment, etc., providing the best quality products and services for your electronic product needs.
