Stainless Steel FeCl₃+HCl

Chemical Etching Formula
SUS301 with FeCl₃+HCl

For engineers selecting an etching chemistry for SUS301, the FeCl₃+HCl formula shown here defines the bath composition, temperature window, and achievable feature sizes across a 0.03-0.3 mm thickness band. Typical mass-production yield for this recipe is 97.6%, with a typical conveyor speed of 1.08 m/min at 48°C.

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.

FeCl₃+HCl Etchant System
44 °Bé Concentration
1.410 Specific Gravity
48 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.03-0.3 mm Thickness Range
0.10 mm Typical Thickness
0.21-6.57 m/min Conveyor Speed Range
1.08 m/min Typical Speed
36-360 μm Min Hole Ø Range
100-300 μm Min Line Width Range
5-53 μm Undercut Range
2.81 Etch Factor (EF)
97.6% Typical Yield (97-97.8%)

Why FeCl₃+HCl for SUS301?

On SUS301, the ferric chloride system attacks the alloy's oxide layer continuously while ferric ions drive dissolution. It is regenerable, compatible with standard photolithography, and produces clean burr-free edges — which is why nearly every SUS301 etch line runs a variant of this formula.

Process Window & Bath Control

Bath control for SUS301 in FeCl₃+HCl: temperature 48°C, concentration 44 °Bé, specific gravity 1.410. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.21-6.57 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 SUS301 at through etch (double-sided), plan for a minimum hole diameter in the 36-360 μm range and a minimum line width in the 100-300 μm range, depending on the chosen sheet thickness within 0.03-0.3 mm. The etch factor of ~2.81 and undercut range of 5-53 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 36-360 μm
• Minimum line width range: 100-300 μm
• Single-side undercut range: 5-53 μm
• Typical etch factor (EF): 2.81

Yield & Production Economics

Expect a yield in the 97-97.8% range for SUS301 with FeCl₃+HCl, with 97.6% typical on a well-controlled line. Most rejects trace back to upstream coating and exposure rather than to the etch bath itself, so tightening photolithography control is usually the fastest path to a higher number.

Typical Applications

Typical applications for SUS301 processed with FeCl₃+HCl include precision shims, encoder discs, RF/EMI shields, surgical and dental components, fuel-cell bipolar plates, and fine filter meshes. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

More Stainless Steel Formulas

Other formulas in the same material family.

AM350 Stainless Steel FeCl₃+HCl Through etch (double-sided) SUS2205 Duplex Stainless FeCl₃+HCl Through etch (double-sided) SUS2507 Super Duplex FeCl₃+HCl Through etch (double-sided) SUS301 FeCl₃+HCl Through etch (double-sided) SUS302 FeCl₃+HCl Through etch (double-sided) SUS303 FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

Standard pre-treatment is degrease, micro-etch to activate the surface, rinse, photoresist lamination or coating, UV exposure through the artwork, and develop. Pre-treatment quality directly drives yield for SUS301: poor degreasing causes resist adhesion failures that show up as random pinhole defects in the etched pattern.

Need a Quote for This Process?

WET Etched runs production wet chemical etching lines using the FeCl₃+HCl chemistry. Send us your part drawing and quantity for a full process quote.

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