Hot Air Solder Leveling (HASL) Process & Equipment

Hot Air Solder Leveling (HASL) is a critical surface finishing process in PCB manufacturing that applies a protective solder coating to copper traces. This technology prevents oxidation and ensures reliable solderability for component assembly. Modern HASL systems integrate precision thermal control, automated handling, and environmental safeguards to deliver consistent results for high-volume production.

Complete HASL Processing System Components:

Pre-HASL Treatment

Chemical cleaning and micro-etching to ensure optimal surface adhesion

Flux Application

Uniform coating to prevent oxidation during soldering

Solder Immersion

Precision dipping in molten solder (230-280°C)

Air Knife Leveling

High-pressure hot air removal of excess solder

Cooling & Cleaning

Controlled solidification and residue removal

Advanced Features of Modern HASL Equipment:

  • Precision Temperature Control: ±1°C accuracy in solder pots (230-280°C range)
  • Dual Air Knife System: Adjustable pressure (5-8kg/cm²) for uniform coating thickness
  • Automated Handling: Robotic arms for consistent immersion and withdrawal
  • Lead-Free Compatibility: SAC305 and other RoHS-compliant alloys
  • Closed-Loop Chemistry Management: Automatic flux density monitoring
  • Energy Recovery Systems: Heat exchange technology reducing power consumption by 30%

Key Applications in Electronics Manufacturing:

  • Surface finishing for consumer electronics PCBs
  • Protection of high-frequency circuit boards
  • Automotive control module production
  • Industrial controller board fabrication
  • LED lighting circuit protection