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.

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.

Process Equipment & Material Reference

Process equipment for the Ag Pure Silver / HNO₃(30%) combination is built around our plasma surface treatment machine platform — closed-loop temperature control, redundant pump headers, and metering for bath replenishment all directly affect the etch factor and yield numbers cited on this page.

If you need a wider view of silver beyond this single recipe, our Silver chemical etching guide covers grade selection, photoresist compatibility, and typical industries that consume this metal in etched form.

Production Use Cases for This Formula

Across the markets we serve, the HNO₃(30%) formula on this page is most often deployed for stainless steel shower-head filter mesh, soy-milk-maker filtration mesh, and stainless steel mesh for aroma diffusers. These applications share thin-feature geometries that benefit from the predictable etch factor near 2.90 and the low single-side undercut documented above.

Adjacent applications usually transfer onto this same formula with no chemistry change, sometimes only a conveyor speed tweak. Drop a drawing and a target volume and we will return a process card built off the parameters on this page.

More Precious Metals Formulas

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Frequently Asked Questions