Borofloat 33 With Cavities – Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); pockets with 5 um floor flatness available. No minimum order; DFM review included with every RFQ.
Our borofloat 33 with cavities cover the full route from blank to inspected part: sawing, CNC profiling, drilling, grinding, polishing and edge finishing under one roof. Borofloat 33 stands out for float-glass flatness off the line and anodic bonding to silicon, and both properties survive our processing because every step is tuned to the material.
Key parameters
| 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 |
| Feature | Cavities |
| Capability | pockets with 5 um floor flatness available |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
DFM notes from the shop floor
Before sending the RFQ, check these against your drawing:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- Feature rule: corner radius R0.5 mm minimum for milled pockets.
- 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.
Capabilities and limits
One material, many routes: on Borofloat 33 we also quote sandblasting, polishing, double-side polishing, ultrasonic machining, and multi-step drawings are the norm rather than the exception.
These features are produced by ultrasonic machining or etching or cnc machining. Capability: pockets with 5 um floor flatness available. Design rule worth copying onto the drawing: corner radius R0.5 mm minimum for milled pockets.
Who orders this
Orders for borofloat 33 with cavities cluster in machine vision (camera windows, ring-light diffusers, calibration plates); mems devices (cap wafers, TGV substrates, motion-sensor lids); microfluidic devices (chips, manifolds, via plates, bonded stacks). Background reading on the underlying material science: SCHOTT BOROFLOAT product page.
The fastest route to a quote is geometry: use the 3D builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Engineers scoping this work usually also review Borofloat 33 selection guide, 4 inch Borofloat wafers, laser glass cutting.
Common questions
Is there a minimum order for borofloat 33 with cavities?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
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.
Specifications on this page were last reviewed by our engineering team in September 2026.