Glass Wafers for Research & Industry
UniversityWafer.com specializes in providing Borofloat 33 and Pyrex 7740 wafers to research institutions. These borosilicate glasses are critical for MEMS applications due to their high chemical resistance and excellent optical clarity.
Why Borofloat 33 for Anodic Bonding?
Anodic bonding is a wafer bonding process to seal glass to silicon or metal without adhesive. Borofloat 33 is chemically modified to match the Coefficient of Thermal Expansion (CTE) of Silicon.
As shown in the graph above, the thermal expansion curves of Silicon and Borofloat 33 overlap significantly up to 400°C. This matching minimizes residual stress and prevents the wafer stack from bowing or cracking during the cooling phase of the bonding process.
Standard Stock Specifications (Always in Stock)
4" (100mm) Borosilicate Glass Wafer
- Material: Borofloat 33 or Pyrex 7740 Equivalent
- Diameter: 100mm +/- 0.3mm
- Thickness: 500µm +/- 25µm (Also available in 175µm, 200µm, 700µm)
- Surface: Double Side Polished (DSP)
- Roughness: < 1.5nm (Ra)
- TTV: < 10µm
- Edge: Ground C-shape with SEMI standard primary flat
- Cleanliness: Cleanroom packed (Class 1000)
Related Materials
We also stock alternatives for specific optical or budgetary requirements: