Chemical Etching Formula
C1100 T2 copper
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 C1100 T2 copper?
On C1100 T2 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 C1100 T2 copper etch line runs a variant of this formula.
Process Window & Bath Control
The process window for this FeCl₃ formula centres on 44°C and 36 °Bé. Conveyor speed spans 5.44-24.33 m/min over the 0.01-0.04 mm thickness band; the typical operating point is 11.25 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
Feature sizes scale with sheet thickness. For this formula the minimum hole diameter ranges 15-42 μm and the minimum line width ranges 100 μm across the 0.01-0.04 mm band, following the industry 1.2× (hole) and 1.0× (line) thickness rules. Single-side undercut ranges 46059 μm, and the etch factor is about 2.85. Size your photomask by subtracting twice the expected undercut from each finished feature dimension.
• Minimum hole diameter range: 15-42 μm
• Minimum line width range: 100 μm
• Single-side undercut range: 46059 μm
• Typical etch factor (EF): 2.85
Yield & Production Economics
Expect a yield in the 98.8% range for C1100 T2 copper with FeCl₃, with 98.8% 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 C1100 T2 copper processed with FeCl₃ include lead frames, busbars, flexible heater elements, RF gaskets, and precision electrical contacts. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.
Process Equipment & Material Reference
On the shop floor, this C1100 T2 copper + FeCl₃ recipe is implemented on a precision acid cleaning machine. The 44°C bath setpoint and 5.44-24.33 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 C1100 T2 copper / FeCl₃ recipe span heat-dissipation vent etching for VC cooling, high-precision etched lead frames, and stainless steel shower-head filter mesh. 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.
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.
More Copper & Brass Formulas
Other formulas in the same material family.
Frequently Asked Questions
Sources & References
- ASTM E407: Standard Practice for Microetching Metals and Alloys
- ASTM B912: Standard Specification for Passivation of Stainless Steels
- Photo Chemical Machining Institute — process capability guidelines
- NIST Engineering Statistics Handbook — process tolerance and capability
Standards are referenced for context. Always confirm parameters against the current published edition and your own process validation.
Need a Quote for This Process?
WET Etched runs production wet chemical etching lines using the FeCl₃ chemistry. Send us your part drawing and quantity for a full process quote.