Carbon & Tool Steel FeCl₃

Chemical Etching Formula
SPCC Cold-Rolled Steel with FeCl₃

For engineers selecting an etching chemistry for SPCC Cold-Rolled Steel, the FeCl₃ formula shown here defines the bath composition, temperature window, and achievable feature sizes across a 0.01-0.5 mm thickness band. Typical mass-production yield for this recipe is 97.3%, with a typical conveyor speed of 0.89 m/min at 46°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 Etchant System
42 °Bé Concentration
1.390 Specific Gravity
46 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.01-0.5 mm Thickness Range
0.13 mm Typical Thickness
0.12-78.25 m/min Conveyor Speed Range
0.89 m/min Typical Speed
8-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
1-91 μm Undercut Range
2.75 Etch Factor (EF)
97.3% Typical Yield (96.3-97.6%)

Why FeCl₃ for SPCC Cold-Rolled Steel?

On SPCC Cold-Rolled Steel, 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 SPCC Cold-Rolled Steel etch line runs a variant of this formula.

Process Window & Bath Control

Hold the bath at 46°C with concentration 42 °Bé (specific gravity 1.390). Across the 0.01-0.5 mm thickness range, conveyor speed runs from 0.12-78.25 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.89 m/min for 0.13 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 8-600 μm, line width 100-500 μm, single-side undercut 1-91 μm — all as a function of thickness across 0.01-0.5 mm. The higher the etch factor (this formula holds about 2.75), the tighter the achievable tolerance. Below the minimum feature sizes, yield falls off steeply, so treat those numbers as hard floors rather than targets.

Design Rule Summary
• Minimum hole diameter range: 8-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 1-91 μm
• Typical etch factor (EF): 2.75

Yield & Production Economics

Typical mass-production yield for SPCC Cold-Rolled Steel in the FeCl₃ system is 97.3%, within an observed range of 96.3-97.6%. 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 SPCC Cold-Rolled Steel processed with FeCl₃ include spring elements, blades, shim stock, and stamped-replacement flat parts. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

More Carbon & Tool Steel Formulas

Other formulas in the same material family.

50CrV4 Spring Steel FeCl₃+HCl Through etch (double-sided) 65Mn Spring Steel FeCl₃+HCl Through etch (double-sided) 65Mn Spring Steel FeCl₃+HCl Half etch (single-sided) DT4 pure iron FeCl₃+HCl Through etch (double-sided) SK2 Tool Steel FeCl₃+HCl Through etch (double-sided) SK3 Tool Steel FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

This formula is documented for a sheet-thickness range of 0.01-0.5 mm, with a typical value of 0.13 mm. Outside this band the same chemistry may still work, but conveyor speed and feature tolerances should be re-verified with a sample run before production.

Need a Quote for This Process?

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

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