The PCB spraying process mainly consists of two core processes: anti-corrosion paint coating and tin spraying, which are respectively used for protection and enhanced welding. The specific process involves key steps such as pre-treatment, spraying operation, curing, and post-treatment. Three-anti-corrosion paint coating process flow Preprocessing. Cleaning: Use a dedicated cleaning agent or ultrasonic waves to remove oil, dust and ionic contamination from the PCB surface (standard requirement: ≤ 1.56 μg/cm²). 2Baking the board: Preheat at 60℃ for 10-20 minutes to remove moisture and enhance the adhesion of the coating. 3 4Shading: The non-coated areas (such as connectors) are protected using tape or a laser mask (with an accuracy of 50 μm). 2 4Application implementation. Method Selection:Brush coating / Dip coating: Suitable for simple board shapes, but with low material utilization rate (dip coating loss reaches 40%). 2Selective Spraying: Accuracy ± 0.1mm, suitable for components below 0402 or high-density boards. 2 5Parameter Control: The spraying thickness is usually 25-75 μm. Be sure to avoid run-off or bubbles. 4 6Solidification and Inspection. Curing method: UV curing (dries within 3-5 seconds), thermal curing (gradually heated to 120℃), or moisture curing (humidity 40-60% RH). 2Quality verification: Through X-ray thickness measurement (with an accuracy of ±1 μm) and salt spray test (no corrosion after 72 hours), etc. 2