Copper Etching Chemical
CAS Number: 7758-98-7
Copper etching chemical is an acidic or alkaline solution used to selectively remove unwanted copper from PCB surfaces during the pattern formation process. Alkaline ammoniacal etchants are preferred for inner layers, while cupric chloride or ferric chloride systems are used in various production environments. Controlled etch rate and undercut characteristics are critical for achieving fine line and space resolution.
Technical Specifications
| pH | 7.5–9.5 (alkaline etchant) |
| etchRate | 25–50 µm/min at operating conditions |
| undercut | <50% of etch depth (fine-line grade) |
| appearance | Blue-green liquid (cupric chloride type) |
| operatingTemp | 45–55°C |
| copperCapacity | Up to 150 g/L Cu (regenerable) |
Applications
- PCB inner and outer layer copper patterning
- Fine line and space etching for HDI
- Controlled depth etching for cavities
- Semiconductor wafer copper etching
- Lead frame etching
Key Features
- High etch rate with minimal undercut for fine features
- Regenerable chemistry for reduced waste and cost
- Consistent etch uniformity across large panels
- Compatible with dry film and liquid photoresist masks