Copper & Brass FeCl₃+HCl

Chemical Etching Formula
C17300 beryllium copper with FeCl₃+HCl

This page documents the reference wet chemical etching formula for C17300 beryllium copper using the FeCl₃+HCl system. The recipe below covers a sheet-thickness range of 0.05-0.3 mm and is configured for through etch (double-sided). Every value is drawn from operational process records rather than theoretical calculation, and is provided as a starting point for your own process development.

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
48 °C Bath Temperature
Through etch (double-sided) Etch Depth Type
0.05-0.3 mm Thickness Range
0.15 mm Typical Thickness
0.19-2.77 m/min Conveyor Speed Range
0.67 m/min Typical Speed
60-360 μm Min Hole Ø Range
100-300 μm Min Line Width Range
9-54 μm Undercut Range
2.78 Etch Factor (EF)
97.2% Typical Yield (96.8-97.5%)

Why FeCl₃+HCl for C17300 beryllium copper?

On C17300 beryllium copper, 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 C17300 beryllium copper etch line runs a variant of this formula.

Process Window & Bath Control

Bath control for C17300 beryllium copper in FeCl₃+HCl: temperature 48°C, concentration 42 °Bé, specific gravity 1.390. The recipe is tuned for through etch (double-sided). Conveyor speed is the primary throughput control, ranging 0.19-2.77 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 60-360 μm, line width 100-300 μm, single-side undercut 9-54 μm — all as a function of thickness across 0.05-0.3 mm. The higher the etch factor (this formula holds about 2.78), the tighter the achievable tolerance. Below the minimum feature sizes, yield falls off steeply, so treat those numbers as hard floors rather than targets.

Design Rule Summary
• Minimum hole diameter range: 60-360 μm
• Minimum line width range: 100-300 μm
• Single-side undercut range: 9-54 μm
• Typical etch factor (EF): 2.78

Yield & Production Economics

Expect a yield in the 96.8-97.5% range for C17300 beryllium copper with FeCl₃+HCl, with 97.2% 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

Parts produced with the FeCl₃+HCl formula on C17300 beryllium copper are common in lead frames, busbars, flexible heater elements, RF gaskets, and precision electrical contacts. The burr-free, stress-free nature of chemical etching makes it the preferred process wherever flatness and edge quality matter more than raw throughput.

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

Across the supported 0.05-0.3 mm thickness range, conveyor speed runs from 0.19-2.77 m/min. A typical mid-range setpoint is 0.67 m/min for 0.15 mm stock. Thinner sheets run faster and thicker sheets slower, roughly in inverse proportion to thickness.

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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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