Chemical Etching Formula
SPCC Cold-Rolled Steel with FeCl₃

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 FeCl₃ for SPCC Cold-Rolled Steel?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like SPCC Cold-Rolled Steel. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on SPCC Cold-Rolled Steel is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Hold the bath at 46°C with concentration 42 °Bé (specific gravity 1.390). Across the 0.01 mm thickness range, conveyor speed runs from 36.37 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 36.37 m/min for 0.01 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 12 μm, line width 100 μm, single-side undercut 2 μm — all as a function of thickness across 0.01 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.

Yield & Production Economics

Typical mass-production yield for SPCC Cold-Rolled Steel in the FeCl₃ system is 97.6%, within an observed range of 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

SPCC Cold-Rolled Steel etched with this recipe typically ends up in spring elements, blades, shim stock, and stamped-replacement flat parts. 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

Production of SPCC Cold-Rolled Steel parts using the FeCl₃ formula described above runs on a biomedical blade etching machine configured for half etch (single-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 Steel 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 SPCC Cold-Rolled Steel / FeCl₃ recipe span custom thin-film heating elements, mobile-phone earpiece mesh, and heat-dissipation vent etching for VC cooling. 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 FeCl₃

The FeCl₃ chemistry is also documented for these alloys.

More Carbon & Tool Steel Formulas

Other formulas in the same material family.

Frequently Asked Questions