Porous Ceramic Vacuum Chuck for Warped Wafer Handling
St.Cera’s porous ceramic chuck is engineered from high-purity alumina with a uniform open porosity of 30–45% and pore sizes ranging from 10 to 100 μm. Unlike conventional grooved chucks, the porous surface provides distributed vacuum across the entire wafer backside, effectively holding warped, thin, or singulated wafers without edge lift-off or breakage. The gentle vacuum (adjustable via restrictor) also prevents backside marking.
Specifications (based on 99.6% Al₂O₃):
| Property | Value |
| Porosity | 30–45% |
| Mean Pore Size | 10–100 μm (selectable) |
| Flexural Strength | ≥250 MPa |
| Flatness (over 300mm) | ≤5 μm |
| Surface Finish | Lapped (Ra 0.8 μm) |
| Max Vacuum Level | -80 kPa |
| Operating Temp | 400°C (air), 600°C (inert) |
| Material | 99.6% Al₂O₃, ZrO₂, or SiC |
Applications:
Thin wafer (≤50 μm) backside grinding
Warped wafer mounting for dicing
Singulated die pick-up from tape
Glass panel handling
Manufacturing & Quality:
Ceramic powder mixed with organic pore formers → pressed → sintered → lapped to final thickness. Each chuck is flow-tested for vacuum uniformity (≤5% deviation) and inspected for pore size distribution (SEM). Flatness measured with laser interferometer.
Advantages over Grooved Chucks:
No wafer edge marking or die shift
Holds warped wafers (up to 500 μm bow)
Eliminates vacuum hole clogging
Self-leveling support for thin substrates
Customization:
Round or rectangular shapes, size up to 600 mm. We can apply edge sealing rings or zone vacuum partitions. Metal-backed versions available for high-rigidity requirements.
Request a sample for your wafer size and warpage test.
