Core Operating Procedures for The SMT Immersion Soldering Machine

Core Operating Procedures for the SMT Immersion Soldering Machine:

1. Operating Procedures

Equipment Preheating

Turn on the power 60 minutes in advance and set the temperature to 260±5°C (calibrated using a temperature controller).

Confirm that the air pressure is stable at 0.5 MPa (if the equipment has an air pressure system).

‌Flux Immersion‌

Clamp the PCB board with a fixture, ensuring only the copper foil side contacts the flux liquid surface to prevent contamination of the component side.

‌Immersion Soldering Operation‌

Slowly immerse the PCB at a 30° angle into the tin liquid, with an immersion depth of 50%-70% of the board thickness.

Immersion time: 3–5 seconds, then lift at a 30° angle at a constant speed.

After immersing 4 PCBs, scrape off the oxide layer on the tin surface to keep the tin liquid clean.

Cooling treatment

Immediately move the PCB to a safe area for natural cooling after immersion; do not touch the uncooled board.

After complete cooling, place it sideways in anti-static equipment, with different models stored in separate zones to prevent friction.

‌II. Safety and Protection Requirements‌

‌Personal Protection‌

Wear a grounded anti-static wristband at all times.

Keep your body 30–50 centimetres away from the solder tank during operation to avoid burns from solder splashes.

‌Equipment Safety‌

Do not touch the interior of the equipment with bare hands or set it to fully automatic mode while it is running.

Immediately press the emergency switch and report any abnormalities.

‌III. Quality Control Points‌

‌Pre-soldering Inspection‌

Confirm that components are properly seated with no misalignment or floating.

Stir the solder paste for 3–5 minutes before use; store unused solder paste in the refrigerator if unused for over 12 hours.

‌Post-soldering Inspection‌

Visual inspection: Solder joints must have no missed solder, cold solder joints, short circuits, solder balls, or solder peaks.

Use a magnifying glass to confirm that ICs have no reverse orientation, displacement, or missing/extra components.

Mark defective products with red arrow labels and record in the report.

‌4. Equipment Maintenance‌

‌Daily Maintenance‌

After shutdown, thoroughly clean the steel mesh/scraper and remove solder residue and flux residues.

Clean the equipment surface with alcohol and keep the work area free of debris.