Chemical Etching Formula
C5191 phosphor bronze 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 C5191 phosphor bronze?

On C5191 phosphor bronze, 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 C5191 phosphor bronze etch line runs a variant of this formula.

Process Window & Bath Control

The process window for this FeCl₃ formula centres on 46°C and 40 °Bé. Conveyor speed spans 0.12-71.44 m/min over the 0.01-0.5 mm thickness band; the typical operating point is 1.33 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 C5191 phosphor bronze 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 ~2.75 and undercut range of 1-91 μm determine how much the mask must be biased to land the finished dimension on target.

Yield & Production Economics

Typical mass-production yield for C5191 phosphor bronze in the FeCl₃ system is 97.9%, within an observed range of 96.7-98.2%. 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

C5191 phosphor bronze etched with this recipe typically ends up in lead frames, busbars, flexible heater elements, RF gaskets, and precision electrical contacts. 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

This C5191 phosphor bronze 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 C5191 phosphor bronze + FeCl₃ formula end up in a wide range of finished products. Representative production runs we have completed using this exact recipe family include tea-infuser custom filter etching, stainless steel mesh for aroma diffusers, and soy-milk-maker filtration mesh. Each case shares the same root sensitivity: clean photoresist edges, a tightly held bath SG of 1.380, and a conveyor speed inside the 0.12-71.44 m/min envelope.

Adjacent applications usually transfer onto this same formula with no chemistry change, sometimes only a conveyor speed tweak. Drop a drawing and a target volume and we will return a process card built off the parameters on this page.

Other Metals Etched with FeCl₃

The FeCl₃ chemistry is also documented for these alloys.

More Copper & Brass Formulas

Other formulas in the same material family.

Frequently Asked Questions