Copper & Brass FeCl₃

Chemical Etching Formula
C1100 T2 copper with FeCl₃

For engineers selecting an etching chemistry for C1100 T2 copper, 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 98.1%, with a typical conveyor speed of 1.25 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
36 °Bé Concentration
1.340 Specific Gravity
46 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.01-0.5 mm Thickness Range
0.10 mm Typical Thickness
0.13-85.05 m/min Conveyor Speed Range
1.25 m/min Typical Speed
8-600 μm Min Hole Ø Range
100-500 μm Min Line Width Range
1-89 μm Undercut Range
2.82 Etch Factor (EF)
98.1% Typical Yield (97.1-98.5%)

Why FeCl₃ for C1100 T2 copper?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like C1100 T2 copper. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on C1100 T2 copper is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

The process window for this FeCl₃ formula centres on 46°C and 36 °Bé. Conveyor speed spans 0.13-85.05 m/min over the 0.01-0.5 mm thickness band; the typical operating point is 1.25 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 C1100 T2 copper at through etch (double-sided), plan for a minimum hole diameter in the 8-600 μm range and a minimum line width in the 100-500 μm range, depending on the chosen sheet thickness within 0.01-0.5 mm. The etch factor of ~2.82 and undercut range of 1-89 μm determine how much the mask must be biased to land the finished dimension on target.

Design Rule Summary
• Minimum hole diameter range: 8-600 μm
• Minimum line width range: 100-500 μm
• Single-side undercut range: 1-89 μm
• Typical etch factor (EF): 2.82

Yield & Production Economics

Expect a yield in the 97.1-98.5% range for C1100 T2 copper with FeCl₃, with 98.1% 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 C1100 T2 copper processed with FeCl₃ include lead frames, busbars, flexible heater elements, RF gaskets, and precision electrical contacts. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

More Copper & Brass Formulas

Other formulas in the same material family.

C1020 OF Copper FeCl₃ Through etch (double-sided) C1100 T2 copper FeCl₃ Through etch (double-sided) C1100 T2 copper FeCl₃ Through etch (double-sided) C1100 T2 copper FeCl₃ Through etch (double-sided) C1100 T2 copper FeCl₃ Half etch (single-sided) C1100 T2 copper FeCl₃ Half etch (single-sided)

Frequently Asked Questions

Minimum line width ranges 100-500 μm over the supported thickness range, per the 1.0× thickness rule. At the fine end, photoresist resolution and adhesion — not the etchant — become the limiting factors, so resist selection matters as much as bath chemistry.

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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