PCB Anti-Tarnish Agent
CAS Number: 95-14-7
PCB anti-tarnish agent is a thin organic surface treatment applied to bare copper and metal surfaces on PCBs to prevent oxidation and tarnishing during storage and handling before assembly. Based on benzotriazole or imidazole chemistry, it forms a monomolecular protective layer that is soldering-compatible and does not impair wettability. Critical for maintaining solderability during long storage periods.
Technical Specifications
| pH | 3.0–5.0 |
| appearance | Clear to slightly yellow liquid |
| concentration | 0.5–5 g/L working solution |
| filmThickness | 0.2–0.5 µm (OSP grade) |
| activeIngredient | Benzotriazole or alkyl imidazole |
| solderabilityRetention | >12 months at 25°C/60%RH |
Applications
- Bare copper PCB storage protection
- OSP (organic solderability preservative) coating
- Silver and tin surface tarnish prevention
- Copper bus bar anti-oxidation treatment
- LED substrate copper protection
Key Features
- Monomolecular film protects without affecting solderability
- Compatible with lead-free reflow soldering
- Easy application by spray, dip, or flood coating
- Thermally decomposed during soldering for clean joints