YFX Machine - Professional SMT machine manufacturer providing one-stop solution.
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). 2
Baking the board: Preheat at 60℃ for 10-20 minutes to remove moisture and enhance the adhesion of the coating. 3 4
Shading: The non-coated areas (such as connectors) are protected using tape or a laser mask (with an accuracy of 50 μm). 2 4
Application implementation.
Method Selection:
Brush coating / Dip coating: Suitable for simple board shapes, but with low material utilization rate (dip coating loss reaches 40%). 2
Selective Spraying: Accuracy ± 0.1mm, suitable for components below 0402 or high-density boards. 2 5
Parameter Control: The spraying thickness is usually 25-75 μm. Be sure to avoid run-off or bubbles. 4 6
Solidification and Inspection.
Curing method: UV curing (dries within 3-5 seconds), thermal curing (gradually heated to 120℃), or moisture curing (humidity 40-60% RH). 2
Quality verification: Through X-ray thickness measurement (with an accuracy of ±1 μm) and salt spray test (no corrosion after 72 hours), etc. 2
Soldering process (HASL)
Preprocessing.
Micro-etching: Sodium peroxide solution corrodes the copper surface by 0.5 - 1 μm, enhancing the adhesion of the tin layer. 7 8
Soldering agent application: Uniform spraying to enhance the wetting property of the solder solution. 7
Soldering operation.
Immersion in tin: Immerse in tin solution at 265 ± 5℃ for 3 to 5 seconds (for lead-free process, it is a Sn96.5/Ag3/Cu0.5 alloy). 8
Hot air leveling: Using a high-pressure air knife at 280-300℃ to level the tin layer, with a thickness controlled at 1-3 μm. 8 9
Post-processing.
Cooling: Rapid cooling (> 4°C/second) is performed to stabilize the structure of the tin layer. 8
Cleaning: Remove residual soldering flux to prevent corrosion. 7
Process Selection Suggestions
Protection requirements: In high-reliability scenarios (such as automotive electronics), polyurethane or silicone three-layer anti-corrosion paint (with a temperature resistance range of 150-200°C) should be preferred. 2
Welding requirements: The tin spraying process has low cost and excellent welding performance, but for high-precision boards, it needs to be combined with processes such as gold plating.
Full inspection of solder paste printing quality
Smallest component
01005 (0.4×0.2mm)
Micro-sized components for mobile phone boards, wearable devices, etc.
Detection accuracy
X/Y: 10-25μm, Z-axis: ≤0.37μm
High-density boards, fine-pitch BGA
Detection speed
Approximately 22.5–91.2 cm²/s (depending on configuration)
High-speed production line, reducing production loss
Board bending compensation ±3mm ~ ±5mm
High- end Shelving Rack Plc And Motor Core Components
DI Makeing Water Machine
Used in semiconductor SMT and other superconducting industries
Supports simultaneous mounting of components of different sizes. Multi-functional surface mount machine.
The core advantages lie in intelligent nitrogen control and modular preheating. It can precisely manage the welding process and optimize nitrogen consumption, making it particularly suitable for scenarios with high requirements for welding quality. It adopts freely defined spraying mode to achieve precise and economical flux deposition. It also comes with an external flux-assisting module with an independent exhaust device, which is separated from the process pipeline and has high flexibility.
In addition, its preheating configuration is modular, with repeatable and stable heat transfer; the solder nozzle combination can be adapted to various application requirements; the chain conveyor system is sturdy and durable, with automatic lubrication; the process pipeline is made of sta
Combined, these features extend the component range down to the 03015mm microchip, yet preserve capability up to 120x90mm components up to 40mm tall and nearly 6” long (150mm) connectors.