Alumina-Based Porous Ceramic Vacuum Chuck for Thin Wafer Handling
St.Cera’s alumina-based porous chuck is fabricated from 99.6% high-purity Al₂O₃ with controlled open porosity of 30–45% and uniform pore size ranging from 10 to 50 μm. Unlike grooved chucks, the porous surface provides distributed vacuum across the entire wafer backside, eliminating edge marking and enabling gentle holding of ultra-thin (≤100 μm) or warped wafers. The material offers flexural strength ≥250 MPa and thermal stability up to 400°C in air.
Specifications (based on 99.6% Al₂O₃):
| Property | Value |
| Material | 99.6% Alumina (White) |
| Porosity | 30–45% (adjustable) |
| Mean Pore Size | 10–50 μm |
| Flexural Strength | ≥250 MPa |
| Density | 3.88 g/cm³ |
| Flatness (over 200mm) | ≤5 μm |
| Max Operating Temp | 400°C (air) |
| Surface Finish | Lapped (Ra ≤0.8 μm) |
Applications:
- · Thin wafer (≤50 μm) backside grinding
- · Warped wafer mounting for dicing
- · Singulated die pick-up
- · Glass substrate handling
Manufacturing:
Powder mixed with pore formers → isostatic pressing → sintering at 1600°C → lapping to final thickness. Each chuck is flow-tested for vacuum uniformity (pressure deviation <5%) and inspected for pore size distribution (SEM).
Advantages over conventional chucks:
- · No wafer backside marking or die shift
- · Holds wafers with bow up to 500 μm
- · Self-cleaning surface (pores resist clogging)
- · Uniform support eliminates local stress
Customization:
Round or square shapes, diameter 100–450 mm. Edge sealing ring available for zoned vacuum control.
Request a sample for your specific wafer size.
