Titanium Alloys HF(8%)+HNO₃(30%)

Chemical Etching Formula
Ta1 Pure Tantalum with HF(8%)+HNO₃(30%)

This reference describes how Ta1 Pure Tantalum responds to the HF(8%)+HNO₃(30%) etching formula. At a bath temperature of 38°C and concentration of as specified, the recipe holds an etch factor of about 2.20 and a typical production yield of 92.7%. It is intended as engineering reference data for design, sourcing, and process planning.

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.

HF(8%)+HNO₃(30%) Etchant System
— °Bé Concentration
1.220 Specific Gravity
38 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.05-0.3 mm Thickness Range
0.15 mm Typical Thickness
0.12-0.87 m/min Conveyor Speed Range
0.19 m/min Typical Speed
60-360 μm Min Hole Ø Range
100-300 μm Min Line Width Range
11-68 μm Undercut Range
2.20 Etch Factor (EF)
92.7% Typical Yield (92.2-92.9%)

Why HF(8%)+HNO₃(30%) for Ta1 Pure Tantalum?

For Ta1 Pure Tantalum, the HF/HNO₃ blend works where chloride chemistries stall: fluoride dissolves the stable oxide, nitric acid re-oxidizes the metal, and the two cycle to give a steady etch. Concentration and temperature control are critical here because the rate is strongly chemistry-dependent.

Process Window & Bath Control

The process window for this HF(8%)+HNO₃(30%) formula centres on 38°C and as specified. Conveyor speed spans 0.12-0.87 m/min over the 0.05-0.3 mm thickness band; the typical operating point is 0.19 m/min. Every 5°C drop in bath temperature requires roughly a 30% reduction in conveyor speed to hold the same etch depth, so temperature stability is the single biggest lever on consistency.

Design Rules & Tolerances

When laying out artwork for Ta1 Pure Tantalum at through etch (double-sided), plan for a minimum hole diameter in the 60-360 μm range and a minimum line width in the 100-300 μm range, depending on the chosen sheet thickness within 0.05-0.3 mm. The etch factor of ~2.20 and undercut range of 11-68 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 60-360 μm
• Minimum line width range: 100-300 μm
• Single-side undercut range: 11-68 μm
• Typical etch factor (EF): 2.20

Yield & Production Economics

Typical mass-production yield for Ta1 Pure Tantalum in the HF(8%)+HNO₃(30%) system is 92.7%, within an observed range of 92.2-92.9%. 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

Ta1 Pure Tantalum etched with this recipe typically ends up in medical implants, surgical instruments, aerospace brackets, and corrosion-resistant filters. 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 Ta1 Pure Tantalum / HF(8%)+HNO₃(30%) combination is built around our wet chemical etching 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.

The Tantalum chemical etching guide reference goes one level above the recipe shown here, surveying the full thickness range, depth options, and common subgrades we run for tantalum.

Production Use Cases for This Formula

Parts produced with this Ta1 Pure Tantalum + HF(8%)+HNO₃(30%) formula end up in a wide range of finished products. Representative production runs we have completed using this exact recipe family include ultrasonic mesh for robotic vacuum cleaners, soy-milk-maker filtration mesh, and juicer filtration mesh etching. Each case shares the same root sensitivity: clean photoresist edges, a tightly held bath SG of 1.220, and a conveyor speed inside the 0.12-0.87 m/min envelope.

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.

More Titanium Alloys Formulas

Other formulas in the same material family.

TA1 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA1 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA1 commercially pure titanium HF(5%)+HNO₃(30%) Half etch (single-sided) TA2 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TA3 commercially pure titanium HF(5%)+HNO₃(30%) Through etch (double-sided) TC1 Titanium Alloy HF(5%)+HNO₃(30%) Through etch (double-sided)

Frequently Asked Questions

This recipe is configured for through etch (double-sided). The 38°C bath, as specified concentration, and 0.12-0.87 m/min conveyor-speed range are tuned for that depth type. Switching between through-etch and half-etch, or single- versus double-sided, requires re-tuning conveyor speed and may change the mask design.
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Reviewed by
Chief Engineer, Wet Etching · WET Etched
Ph.D., Metallurgical & Chemical Engineering, Xiamen University

Sources & References

Standards are referenced for context. Always confirm parameters against the current published edition and your own process validation.

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WET Etched runs production wet chemical etching lines using the HF(8%)+HNO₃(30%) chemistry. Send us your part drawing and quantity for a full process quote.

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