Double-Side Polishing Alkali-Free Glass: Alkali-Free Glass (CTE 3.2 x 10^-6 /K, 350 nm – 2.0 um); Double-Side Polishing to TTV under 3 um. Single-piece prototypes to production volumes, quoted from your drawing.
We DSP-polish Alkali-Free Glass daily, in thicknesses from 0.1 – 10 mm. The controlling numbers: TTV under 3 um working tolerance, Ra below 0.5 nm both faces minimum features, and 60/40 to 20/10 both faces off the machine. Where the drawing asks for more, downstream lapping and polishing take over.
Specifications at a glance
| 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 | Double-Side Polishing |
| Working tolerance | TTV under 3 um |
| Minimum feature | Ra below 0.5 nm both faces |
| Surface finish | 60/40 to 20/10 both faces |
| Thickness window | 0.1 – 10 mm |
| Edge condition | edge-rounded before DSP |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Manufacturing capability
The core strength of Double-Side Polishing is wafer-grade parallelism and sub-nanometer roughness on both faces simultaneously. The honest limit: parts must be round or near-round; strongly asymmetric outlines wedge in the carriers. Both belong on the drawing before quoting, not after.
One material, many routes: on Alkali-Free Glass we also quote grinding, cnc machining, polishing, laser cutting, and multi-step drawings are the norm rather than the exception.
Design guidance
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: parts must be round or near-round; strongly asymmetric outlines wedge in the carriers.
- 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.
The full rules live in our tolerance design guide and holes and edges design guide.
Typical applications
Orders for double-side polishing alkali-free glass cluster in oled packaging (cover lids, frit-seal frames, fill-port plates); ccd inspection equipment (CCD cover plates, reference grids, stage glass); industrial displays (touch covers, gauge windows, printed bezels). Background reading on the underlying material science: SCHOTT AF 32 eco.
Dimensions still moving? Configure this part live in the 3D builder below, or open the full custom glass machining 3D builder to start from a blank canvas.
For adjacent specifications, see alkali-free display glass, alkali-free glass wafers, machining tolerance guide.
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 double-side polishing hold?
TTV under 3 um with minimum features of Ra below 0.5 nm both faces. Parts must be round or near-round; strongly asymmetric outlines wedge in the carriers.
What equipment runs the double-side polishing work?
Planetary double-side polishers with carrier plates.
Specifications on this page were last reviewed by our engineering team in July 2026.