Chemical Etching Formula
Ta-2.5W Tantalum Alloy with HF(8%)+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 HF(8%)+HNO₃(30%) for Ta-2.5W Tantalum Alloy?

Hydrofluoric/nitric formulas are used for refractory and titanium-family metals such as Ta-2.5W Tantalum Alloy because the fluoride ion is one of the few species that will break down their tenacious passive oxide. The nitric component oxidizes the freshly exposed metal so the fluoride can keep working. Handling demands are high, but for Ta-2.5W Tantalum Alloy there is rarely a practical alternative.

Process Window & Bath Control

Bath control for Ta-2.5W Tantalum Alloy in HF(8%)+HNO₃(30%): temperature 40°C, concentration as specified, specific gravity 1.220. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.12-0.87 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

Design rules for this recipe: hole diameter 60-360 μm, line width 100-300 μm, single-side undercut 11-69 μm — all as a function of thickness across 0.05-0.3 mm. The higher the etch factor (this formula holds about 2.18), 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

This formula delivers a typical yield of 92.7% (range 92.2-92.9%). At that rate, per-part economics are driven mostly by fixed photomask and setup cost for small batches and by sheet utilisation for large runs. The chemistry itself does not change with quantity, so the same recipe serves prototype and production volumes.

Typical Applications

Parts produced with the HF(8%)+HNO₃(30%) formula on Ta-2.5W Tantalum Alloy are common in implantable electronics, capacitor anodes, and chemical-process components. The burr-free, stress-free nature of chemical etching makes it the preferred process wherever flatness and edge quality matter more than raw throughput.

Process Equipment & Material Reference

Production of Ta-2.5W Tantalum Alloy parts using the HF(8%)+HNO₃(30%) formula described above runs on a knife-mold 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 Tantalum 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 Ta-2.5W Tantalum Alloy / HF(8%)+HNO₃(30%) recipe span stainless filtration mesh for vacuum cleaners, cold-press juicer filtration mesh, and high-speed air-intake mesh for hair dryers. 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.

If your part falls into one of these classes — or a closely adjacent one — this formula is usually the right starting point. We confirm fit with a short sample run on the actual sheet stock before locking in mask artwork.

Other Metals Etched with HF(8%)+HNO₃(30%)

The HF(8%)+HNO₃(30%) chemistry is also documented for these alloys.

Frequently Asked Questions