Chemical Etching Formula
C5101 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 C5101 phosphor bronze?

On C5101 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 C5101 phosphor bronze etch line runs a variant of this formula.

Process Window & Bath Control

Bath control for C5101 phosphor bronze in FeCl₃: temperature 46°C, concentration 40 °Bé, specific gravity 1.380. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.12-2.77 m/min across the supported thickness range. Check specific gravity each shift with a calibrated hydrometer and correct with fresh make-up or water as needed.

Design Rules & Tolerances

Design rules for this recipe: hole diameter 60-600 μm, line width 100-500 μm, single-side undercut 9-91 μm — all as a function of thickness across 0.05-0.5 mm. The higher the etch factor (this formula holds about 2.74), 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

Expect a yield in the 96.7-97.8% range for C5101 phosphor bronze with FeCl₃, with 97.4% 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

C5101 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

On the shop floor, this C5101 phosphor bronze + FeCl₃ recipe is implemented on a precision acid cleaning machine. The 46°C bath setpoint and 0.12-2.77 m/min conveyor range correspond to verified production envelopes on that equipment for through etch (double-sided).

The Copper chemical etching guide reference goes one level above the recipe shown here, surveying the full thickness range, depth options, and common subgrades we run for copper.

Production Use Cases for This Formula

Production examples for the C5101 phosphor bronze / FeCl₃ recipe span stainless filtration mesh for vacuum cleaners, high-speed air-intake mesh for hair dryers, 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.

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

The FeCl₃ chemistry is also documented for these alloys.

More Copper & Brass Formulas

Other formulas in the same material family.

Frequently Asked Questions