Etching Alkali-Free Glass: Alkali-Free Glass (CTE 3.2 x 10^-6 /K, 350 nm – 2.0 um); Etching to depth control +/-1 um. Single-piece prototypes to production volumes, quoted from your drawing.
The combination of Alkali-Free Glass and Etching comes up constantly in RFQs for a reason – the material offers display-grade surface quality, and Etching is the right way to get accurate geometry into it. Expect depth control +/-1 um and isotropic smooth walls.
The numbers
| Material | Alkali-Free Glass (AF32 / EAGLE-class display glass) |
|---|---|
| Thermal expansion (CTE) | 3.2 x 10^-6 /K |
| Service temperature | 600 C (Tg 717 C) |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.43 g/cm3 |
| Knoop hardness | 590 kg/mm2 |
| Refractive index | 1.51 @ 587 nm |
| Stock thickness | 0.10 – 1.1 mm |
| Maximum blank size | 400 x 300 mm |
| Process | Etching |
| Working tolerance | depth control +/-1 um |
| Minimum feature | 10 um channel width (masked HF) |
| Surface finish | isotropic smooth walls |
| Thickness window | 0.1 – 5 mm |
| Edge condition | stress-relief etch available |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Specification advice
Before sending the RFQ, check these against your drawing:
- Material note: thin sheets below 0.3 mm demand carrier-supported handling through every step.
- Process boundary: isotropic undercut roughly equals depth, so masks are compensated at layout time.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
For the complete framework, see the tolerance design guide and the holes and edges design guide.
What the process holds
Etching earns its place through microchannels, cavities and frosted textures without mechanical stress. Its boundary condition – isotropic undercut roughly equals depth, so masks are compensated at layout time – is the first thing our DFM review checks.
Beyond this page, Alkali-Free Glass routinely runs through polishing, double-side polishing, edge grinding, lapping in our shop – most real parts combine two or three of these steps.
Application context
etching alkali-free glass shows up across industrial displays (touch covers, gauge windows, printed bezels); oled packaging (cover lids, frit-seal frames, fill-port plates); mems devices (cap wafers, TGV substrates, motion-sensor lids). Background reading on the underlying material science: SCHOTT AF 32 eco.
The fastest route to a quote is geometry: use the 3D configurator below, or the site-wide custom glass machining 3D builder for fully custom parts.
Related reading on this site: alkali-free display glass, alkali-free glass wafers, JGS1 quartz glass.
Buyer questions, answered
What tolerances are achievable on Alkali-Free Glass parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Thin sheets below 0.3 mm demand carrier-supported handling through every step.
What thickness range do you stock for Alkali-Free Glass?
Standard stock spans 0.10 – 1.1 mm, with blanks up to 400 x 300 mm. Other formats are sourced per order.
How does Alkali-Free Glass behave under heat?
CTE is 3.2 x 10^-6 /K and continuous service reaches 600 C (Tg 717 C), which is what drives its use where no alkali ion migration into TFT or sensor layers matters.
What accuracy does etching hold?
Depth control +/-1 um with minimum features of 10 um channel width (masked HF). Isotropic undercut roughly equals depth, so masks are compensated at layout time.
What equipment runs the etching work?
Buffered HF wet benches and masked lithography line.
Specifications on this page were last reviewed by our engineering team in July 2026.