Double-Side Polishing Borofloat 33 Wafers: Borofloat 33 (CTE 3.25 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.
Ask any process engineer what makes borofloat 33 difficult and the answer is specific: float tin side must be tracked when parts see coating or bonding steps. Our double-side polishing line is tooled around exactly that – planetary double-side polishers with carrier plates – holding TTV under 3 um on parts from 0.1 – 10 mm thick.
Specification envelope
| Material | Borofloat 33 (SCHOTT float production, wafer grade) |
|---|---|
| Thermal expansion (CTE) | 3.25 x 10^-6 /K |
| Service temperature | 450 C continuous |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.23 g/cm3 |
| Knoop hardness | 480 kg/mm2 |
| Refractive index | 1.471 @ 587 nm |
| Stock thickness | 0.70 – 25.4 mm |
| Maximum blank size | 500 x 500 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 |
| Wafer formats | 2", 3", 4", 6", 8" and 12" with SEMI flats or notch |
| TTV | under 3 – 5 um by format |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Capabilities and limits
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 Borofloat 33 we also quote coring, etching, dicing, polishing, and multi-step drawings are the norm rather than the exception.
Design guidance
The shop-floor rules that matter here:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- 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.
Application context
double-side polishing borofloat 33 wafers shows up across mems devices (cap wafers, TGV substrates, motion-sensor lids); machine vision (camera windows, ring-light diffusers, calibration plates); led packaging (groove covers, phosphor carriers, package windows). Background reading on the underlying material science: SCHOTT BOROFLOAT product page.
Dimensions still moving? Configure this part live in the 3D + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
For adjacent specifications, see Borofloat 33 selection guide, 4 inch Borofloat wafers, custom ITO glass.
Buyer questions, answered
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
What files do you need for a quote?
A dimensioned PDF plus DXF or STEP geometry. If only a sketch exists, our drawing review service formalizes it before quoting.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
What tolerances are achievable on Borofloat 33 parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Float tin side must be tracked when parts see coating or bonding steps.
What thickness range do you stock for Borofloat 33?
Standard stock spans 0.70 – 25.4 mm, with blanks up to 500 x 500 mm. Other formats are sourced per order.
Specifications on this page were last reviewed by our engineering team in October 2026.