Chemical Etching Formula
Ag Pure Silver
with HNO₃(30%)
Formula Summary
The table below summarizes every parameter that defines this etching formula. Values listed as ranges scale with sheet thickness across the supported band.
Why HNO₃(30%) for Ag Pure Silver?
For Ag Pure Silver, HNO₃(30%) provides controllable, regenerable etching with predictable undercut. The chloride or acid species continuously break down the alloy's protective oxide while the oxidizer supplies the electrochemical driving force, producing clean, burr-free edges compatible with standard dry-film and liquid photoresists.
Process Window & Bath Control
Bath control for Ag Pure Silver in HNO₃(30%): temperature 26°C, concentration as specified, specific gravity 1.180. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.73-8.61 m/min across the supported thickness range. Check specific gravity each shift with a calibrated hydrometer and correct with fresh make-up or water as needed.
Design Rules & Tolerances
When laying out artwork for Ag Pure Silver at through etch (double-sided), plan for a minimum hole diameter in the 36-240 μm range and a minimum line width in the 100-200 μm range, depending on the chosen sheet thickness within 0.03-0.2 mm. The etch factor of ~2.90 and undercut range of 5-34 μm determine how much the mask must be biased to land the finished dimension on target.
• Minimum hole diameter range: 36-240 μm
• Minimum line width range: 100-200 μm
• Single-side undercut range: 5-34 μm
• Typical etch factor (EF): 2.90
Yield & Production Economics
Typical mass-production yield for Ag Pure Silver in the HNO₃(30%) system is 98.8%, within an observed range of 98.6-98.9%. The dominant yield-loss modes are photoresist pinhole defects and rinse-water contamination. Improving incoming sheet quality and photoresist coating consistency gives the highest yield-improvement leverage for this formula.
Typical Applications
Ag Pure Silver etched with this recipe typically ends up in fine jewelry components, electrical contacts, and decorative inlays. Because chemical etching applies no mechanical or thermal load, the finished features are free of work-hardening and heat-affected zones — a decisive advantage over stamping or laser cutting for these uses.
More Precious Metals Formulas
Other formulas in the same material family.
Frequently Asked Questions
Need a Quote for This Process?
WET Etched runs production wet chemical etching lines using the HNO₃(30%) chemistry. Send us your part drawing and quantity for a full process quote.