Metallization Borofloat 33: Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); films 50 nm – 2 um, patterned to 10 um lines. Single-piece prototypes to production volumes, quoted from your drawing.
metallization borofloat 33 is Cr/Au, Ti/Pt or Al thin films applied by sputter + lift-off or shadow mask. On Borofloat 33 it solderable pads, mirrors and electrodes on glass – the specification we run to is films 50 nm – 2 um, patterned to 10 um lines.
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 |
| Treatment | Metallization – Cr/Au, Ti/Pt or Al thin films |
| Specification | films 50 nm – 2 um, patterned to 10 um lines |
| Deposition / method | sputter + lift-off or shadow mask |
| 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.
- Sequence matters: all machining happens before metallization; post-coating rework is not economical.
- 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.
Process window
Beyond this page, Borofloat 33 routinely runs through laser cutting, sandblasting, lapping, edge grinding in our shop – most real parts combine two or three of these steps.
Application context
Orders for metallization borofloat 33 cluster in mems devices (cap wafers, TGV substrates, motion-sensor lids); optical sensors (sensor windows, filter caps, lens covers); 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 wafer dicing process, 4 inch Borofloat wafers, glass in laser systems.
Frequently asked questions
How does Borofloat 33 behave under heat?
CTE is 3.25 x 10^-6 /K and continuous service reaches 450 C continuous, which is what drives its use where float-glass flatness off the line matters.
What does metallization add?
Solderable pads, mirrors and electrodes on glass. Applied by sputter + lift-off or shadow mask to films 50 nm – 2 um, patterned to 10 um lines.
Is there a minimum order for metallization borofloat 33?
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.
Specifications on this page were last reviewed by our engineering team in August 2026.