3 Inch (76.2 mm) Fused Silica Wafers – Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); 76.2 mm format, TTV <5 um. No minimum order; DFM review included with every RFQ.
3 inch (76.2 mm) fused silica wafers are supplied as finished substrates: edge-rounded, cleaned and packed in wafer cassettes. The material brings near-zero thermal expansion and deep-UV transmission; the format brings SEMI-compatible handling.
Specifications at a glance
| Material | Fused Silica (JGS1 (UV), JGS2 (standard), JGS3 (IR)) |
|---|---|
| Thermal expansion (CTE) | 0.55 x 10^-6 /K |
| Service temperature | 1,100 C continuous |
| Transmission range | 185 nm – 2.5 um |
| Density | 2.20 g/cm3 |
| Knoop hardness | 500 kg/mm2 |
| Refractive index | 1.458 @ 587 nm |
| Stock thickness | 0.10 – 50 mm |
| Maximum blank size | 450 x 450 mm |
| Diameter / format | 76.2 mm |
| Thickness | 0.3 – 1.0 mm typical |
| TTV | <5 um |
| Flat / notch | SEMI flat |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Capabilities and limits
One material, many routes: on Fused Silica we also quote lapping, laser cutting, polishing, ultrasonic machining, and multi-step drawings are the norm rather than the exception.
Specification advice
Before sending the RFQ, check these against your drawing:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Specify flat or notch orientation relative to your device layout – regrinding orientation later scraps the wafer.
- 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.
Where these parts end up
The recurring buyers of 3 inch (76.2 mm) fused silica wafers: microfluidic devices (chips, manifolds, via plates, bonded stacks); mems devices (cap wafers, TGV substrates, motion-sensor lids); semiconductor equipment (view ports, wafer carriers, plasma rings, chamber windows). Background reading on the underlying material science: RP Photonics: fused silica.
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 fused silica wafer applications, material selection guide, perforated quartz plates.
Common questions
How does Fused Silica behave under heat?
CTE is 0.55 x 10^-6 /K and continuous service reaches 1,100 C continuous, which is what drives its use where near-zero thermal expansion matters.
Is there a minimum order for 3 inch (76.2 mm) fused silica wafers?
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.