Copper & Brass FeCl₃+HCl

Chemical Etching Formula
C7150 Cupronickel with FeCl₃+HCl

The FeCl₃+HCl chemistry is a proven formula for C7150 Cupronickel. This reference sheet lists the concentration (42 °Bé), specific gravity (1.390), bath temperature (46°C), and the full range of conveyor speeds and feature tolerances that result. Use it to size your process before committing to a production trial.

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
42 °Bé Concentration
1.390 Specific Gravity
46 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.05-0.3 mm Thickness Range
0.15 mm Typical Thickness
0.19-2.83 m/min Conveyor Speed Range
0.68 m/min Typical Speed
60-360 μm Min Hole Ø Range
100-300 μm Min Line Width Range
9-56 μm Undercut Range
2.70 Etch Factor (EF)
96.9% Typical Yield (96.5-97.1%)

Why FeCl₃+HCl for C7150 Cupronickel?

On C7150 Cupronickel, 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 C7150 Cupronickel 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 0.05-0.3 mm thickness range, conveyor speed runs from 0.19-2.83 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.68 m/min for 0.15 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

When laying out artwork for C7150 Cupronickel 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 ~2.70 and undercut range of 9-56 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: 9-56 μm
• Typical etch factor (EF): 2.70

Yield & Production Economics

This formula delivers a typical yield of 96.9% (range 96.5-97.1%). At that rate, per-part economics are driven mostly by fixed photomask and setup cost for small batches and by sheet utilisation for large runs. The chemistry itself does not change with quantity, so the same recipe serves prototype and production volumes.

Typical Applications

Typical applications for C7150 Cupronickel processed with FeCl₃+HCl 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 Through etch (double-sided) C1100 T2 copper FeCl₃ Half etch (single-sided)

Frequently Asked Questions

Yes. The FeCl₃+HCl chemistry and 46°C bath are identical from a single prototype part up to full production — the chemistry does not depend on quantity. Conveyor speed stays in the 0.19-2.83 m/min range. Only the per-part economics shift, since fixed photomask and setup costs dominate at low volumes.

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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