Precision Alloys FeCl₃+HCl

Chemical Etching Formula
1J85 Super-Permalloy with FeCl₃+HCl

This page documents the reference wet chemical etching formula for 1J85 Super-Permalloy 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
44 °Bé Concentration
1.410 Specific Gravity
50 °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
2.77 Etch Factor (EF)
96.6% Typical Yield (96.1-96.8%)

Why FeCl₃+HCl for 1J85 Super-Permalloy?

Ferric-chloride-based formulas are the industrial workhorse for ferrous, nickel, and copper-bearing alloys like 1J85 Super-Permalloy. The Fe³⁺ ion oxidizes the metal surface; where HCl is present it regenerates dissolved species and stabilizes chloride concentration. The result on 1J85 Super-Permalloy is anisotropic etching with predictable undercut and an easily regenerated spent bath.

Process Window & Bath Control

Hold the bath at 50°C with concentration 44 °Bé (specific gravity 1.410). Across the 0.05-0.3 mm thickness range, conveyor speed runs from 0.19-2.77 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 0.67 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

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 2.77), 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): 2.77

Yield & Production Economics

Expect a yield in the 96.1-96.8% range for 1J85 Super-Permalloy with FeCl₃+HCl, with 96.6% 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

Typical applications for 1J85 Super-Permalloy processed with FeCl₃+HCl include hermetic sealing rings, lead frames matched to glass/ceramic, and magnetic shielding. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

More Precision Alloys Formulas

Other formulas in the same material family.

1J22 Iron-Cobalt Alloy FeCl₃+HCl Through etch (double-sided) 1J46 Permalloy FeCl₃+HCl Through etch (double-sided) 1J50 Permalloy FeCl₃+HCl Through etch (double-sided) 1J79 Permalloy FeCl₃+HCl Through etch (double-sided) HyMu80 (Permalloy) FeCl₃+HCl Through etch (double-sided) Invar36 alloy FeCl₃+HCl Through etch (double-sided)

Frequently Asked Questions

The typical etch factor for this recipe is 2.77 — vertical etch depth is about 2.77× the single-side undercut. Higher EF means tighter feature tolerance; values near or above 3.0 are close to best-in-class for wet etching, and 1J85 Super-Permalloy in FeCl₃+HCl sits in the typical production range.

Need a Quote for This Process?

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.

Request a Quote Browse Formulas