Chemical Etching Formula
C7150 Cupronickel with FeCl₃+HCl

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+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.

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.

Process Equipment & Material Reference

This C7150 Cupronickel formula is part of the standard process library running on our wet chemical etching machine. The same chemistry can be ported to any horizontal spray-etching line of comparable nozzle layout and bath-titration discipline.

For a broader treatment of the material itself — alloy variants, surface preparation, and process limits across thickness ranges — see our Copper chemical etching guide. That overview complements the formula-specific bath and conveyor data on this page.

Production Use Cases for This Formula

Parts produced with this C7150 Cupronickel + FeCl₃+HCl formula end up in a wide range of finished products. Representative production runs we have completed using this exact recipe family include stainless filtration mesh for vacuum cleaners, stainless steel shower-head filter mesh, and soy-milk-maker filtration mesh. Each case shares the same root sensitivity: clean photoresist edges, a tightly held bath SG of 1.390, and a conveyor speed inside the 0.19-2.83 m/min envelope.

Designs that sit slightly outside this thickness or feature-size envelope are usually addressable by a sister formula in the same etchant family. The bath chemistry stays the same; the tuning shifts to conveyor speed and resist choice.

Other Metals Etched with FeCl₃+HCl

The FeCl₃+HCl chemistry is also documented for these alloys.

More Copper & Brass Formulas

Other formulas in the same material family.

Frequently Asked Questions