Germanium Chemical Etching — Engineering Reference
Wet chemical etching of Germanium is a precision subtractive process that defines fine features by selectively dissolving the metal through a photoresist-patterned mask. On Germanium specifically, the etchant choice, bath temperature, and conveyor speed combine to set the etch factor, undercut, and yield envelope every production run lives in.
Why Wet Chemical Etching for Germanium?
Compared to laser, stamping, or wire EDM, wet chemical etching imparts no mechanical or thermal load to Germanium. The process is parallel — every feature on a sheet etches simultaneously — so feature count has no impact on tooling cost. For Germanium parts with hundreds or thousands of micro-features per piece, that is the dominant economic argument.
- Burr-free, stress-free edges — no post-deburring on Germanium required.
- Tooling cost flat with feature complexity — only the photomask changes.
- Fast prototype iteration — artwork edits, not tool re-cuts.
- Tight tolerance on thin gauge Germanium (down to ±25 μm in production).
- Compatible with downstream passivation, plating, electropolishing.
Process Window for Germanium
Production lines etching Germanium run a closed-loop temperature band of typically ±1.5 °C, with bath specific gravity monitored each shift via hydrometer or refractometer. Conveyor speed inversely tracks sheet thickness: thinner stock runs faster, thicker stock slower, with the goal of holding etch factor (EF) above 2.5 and single-side undercut below thirty microns wherever possible. For Germanium, the recommended chemistry is H₂O₂(30%)+NH₃(25%).
| Recommended etchant | H₂O₂(30%)+NH₃(25%) |
|---|---|
| Bath temperature window | 40 – 55 °C (chemistry-dependent) |
| Specific gravity setpoint | 1.30 – 1.45 g/cm³ for ferric chloride systems |
| Conveyor speed range | 0.4 – 8.0 m/min (thickness-dependent) |
| Typical etch factor (EF) | 2.5 – 3.0 |
| Single-side undercut | 5 – 40 μm depending on depth and thickness |
| Minimum hole diameter | ≈ 1.2× sheet thickness |
| Minimum line width | ≈ 1.0× sheet thickness |
| Mass-production yield | 95 – 99% on mature recipes for Germanium |
Common Applications for Chemically Etched Germanium
Across the markets we serve, chemically etched Germanium is most often deployed in filtration meshes, lead frames and connector blanks, surgical and consumer blades, EMI shielding gaskets, heat-dissipation vents, and decorative architectural pieces. Thickness and feature complexity push different applications onto different recipes.
Related Recipes & Process Parameters
Every formula and parameter row below is a live page on this site with the full chemistry, conveyor speed, and tolerance window for the exact material-thickness-etchant combination. These are the references our process engineers cite from on production shifts.
Related Material References
Related Production Applications
Related Process Equipment
Frequently Asked Questions
What thickness range is supported for Germanium?
Production runs on Germanium typically cover 0.02 mm to 2.0 mm sheet stock. Different thicknesses use the same chemistry; only conveyor speed and feature tolerances change.
What edge quality can I expect when etching Germanium?
Wet chemical etching is non-contact, so etched Germanium parts are completely burr-free, stress-free, and free of any heat-affected zone. Final edge cleanliness depends on photoresist adhesion and rinse cascade discipline.
How is bath chemistry maintained over a production shift on Germanium?
The H₂O₂(30%)+NH₃(25%) bath is titrated at shift start and replenished with concentrated stock + water based on specific-gravity drift. Spent bath is regenerated electrolytically where possible.
Which etchant works best for Germanium?
The recommended starting chemistry is H₂O₂(30%)+NH₃(25%). It balances etch rate, bath stability, and photoresist compatibility for Germanium across the production thickness range.
Frequently Asked Questions
What tolerances can you achieve for Wet Chemical Etching Germanium?
Photochemical etching holds tight, repeatable tolerances on thin metal, which makes it well suited to Wet Chemical Etching Germanium. Exact figures depend on material and thickness.
Can Wet Chemical Etching Germanium be customised to my drawing?
Yes. Wet Chemical Etching Germanium is made to order from your CAD/artwork, so dimensions, features and material are all tailored to your specification.
What is the typical lead time and minimum order for Wet Chemical Etching Germanium?
Because etching needs no hard tooling, Wet Chemical Etching Germanium can be prototyped quickly and scaled to volume. Share your drawing and quantity and we will advise lead time.