Chemical Etching Formula
W1 Pure Tungsten with H₂O₂(30%)+NH₃(25%)

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 H₂O₂(30%)+NH₃(25%) for W1 Pure Tungsten?

For W1 Pure Tungsten, H₂O₂(30%)+NH₃(25%) 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

Hold the bath at 58°C with concentration as specified (specific gravity 1.120). Across the 0.05-0.3 mm thickness range, conveyor speed runs from 0.12-0.98 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.20 m/min for 0.15 mm stock. Use redundant PID temperature control to hold the bath within ±1.5°C, and titrate at least once per shift.

Design Rules & Tolerances

Design rules for this recipe: hole diameter 60-360 μm, line width 100-300 μm, single-side undercut 11-65 μm — all as a function of thickness across 0.05-0.3 mm. The higher the etch factor (this formula holds about 2.30), the tighter the achievable tolerance. Below the minimum feature sizes, yield falls off steeply, so treat those numbers as hard floors rather than targets.

Yield & Production Economics

Typical mass-production yield for W1 Pure Tungsten in the H₂O₂(30%)+NH₃(25%) system is 93.1%, within an observed range of 92.8-93.4%. 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

Typical applications for W1 Pure Tungsten processed with H₂O₂(30%)+NH₃(25%) include X-ray collimator grids, electron-beam apertures, and high-density precision masks. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

Process Equipment & Material Reference

Production of W1 Pure Tungsten parts using the H₂O₂(30%)+NH₃(25%) formula described above runs on a wet chemical etching machine configured for through etch (double-sided). The bath chemistry, conveyor speed, and rinse cascade detailed on this page reflect the operating profile we use on a live spray-etching line for this alloy.

For a broader treatment of the material itself — alloy variants, surface preparation, and process limits across thickness ranges — see our Tungsten chemical etching guide. That overview complements the formula-specific bath and conveyor data on this page.

Production Use Cases for This Formula

Production examples for the W1 Pure Tungsten / H₂O₂(30%)+NH₃(25%) recipe span juicer filtration mesh etching, soy-milk-maker filtration mesh, and stainless steel metal filter mesh. In every case, the etch factor and undercut figures on this page are the dominant tolerance drivers — bath maintenance discipline matters more than equipment headline rating.

Designs that sit slightly outside this thickness or feature-size envelope are usually addressable by a sister formula in the same etchant family. The bath chemistry stays the same; the tuning shifts to conveyor speed and resist choice.

Other Metals Etched with H₂O₂(30%)+NH₃(25%)

The H₂O₂(30%)+NH₃(25%) chemistry is also documented for these alloys.

More Tungsten Formulas

Other formulas in the same material family.

Frequently Asked Questions