Chemical Etching Formula
Al7050 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 Al7050?

On Al7050, 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 Al7050 etch line runs a variant of this formula.

Process Window & Bath Control

The process window for this FeCl₃+HCl formula centres on 44°C and 36 °Bé. Conveyor speed spans 0.12-2.9 m/min over the 0.05-0.5 mm thickness band; the typical operating point is 0.42 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

Design rules for this recipe: hole diameter 60-600 μm, line width 100-500 μm, single-side undercut 10-101 μm — all as a function of thickness across 0.05-0.5 mm. The higher the etch factor (this formula holds about 2.47), 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

Typical mass-production yield for Al7050 in the FeCl₃+HCl system is 97.5%, within an observed range of 96.8-97.9%. 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

Al7050 etched with this recipe typically ends up in lightweight RF shields, heat-spreader masks, nameplates, decorative trim, and lightweight structural lattices. 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

Production of Al7050 parts using the FeCl₃+HCl formula described above runs on a biomedical blade etching machine configured for through etch (double-sided). The bath chemistry, conveyor speed, and rinse cascade detailed on this page reflect the operating profile we use on a live spray-etching line for this alloy.

Related to this formula, the Aluminum chemical etching guide page documents the full process envelope for the same alloy family, including pre-treatment chemistry and post-etch inspection criteria.

Production Use Cases for This Formula

Typical end-uses for Al7050 run on this formula include stainless filtration mesh for vacuum cleaners, stainless steel mesh for aroma diffusers, and stainless steel metal filter mesh. The 44°C bath and 0.05-0.5 mm supported thickness range cover most of the production work in these segments without re-tuning chemistry.

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 Aluminum Alloys Formulas

Other formulas in the same material family.

Frequently Asked Questions