HASL Surface Finish (Hot Air Solder Leveling)
CAS Number: 7440-31-5
HASL (Hot Air Solder Leveling) is a PCB surface finish process where bare copper pads are coated with molten solder and excess solder is removed by hot air knives, leaving a solderable tin-lead or lead-free solder coating. It is one of the oldest and most cost-effective PCB surface finishes, providing excellent solderability and long shelf life. Lead-free HASL uses SAC alloys to comply with RoHS requirements.
Technical Specifications
| standard | IPC-4554 |
| shelfLife | >12 months |
| processTemp | 230–260°C (lead-free HASL) |
| solderAlloy | Sn63Pb37 or SAC305 (lead-free) |
| solderability | Passes J-STD-003 |
| coatingThickness | 1–25 µm (varies by geometry) |
Applications
- Standard PCB surface finish for through-hole and SMT
- Cost-sensitive consumer electronics PCBs
- Industrial control board surface protection
- Automotive non-critical PCB finish
- Double-sided PCB assembly
Key Features
- Most cost-effective PCB surface finish
- Excellent solderability and long shelf life
- Lead-free SAC alloy option for RoHS compliance
- Suitable for both through-hole and SMT assembly