Bernoulli Ceramic End Effector — Non-Contact Wafer Handling for Thin & Fragile Wafers

St.Cera‘s Bernoulli ceramic end effector uses aerodynamic lift to handle wafers without physical contact. Manufactured from high-purity 99.8% alumina (Al₂O₃) or silicon carbide (SiC), it features precision-machined nozzles that eject pressurized gas to create a thin air film between the end effector and the wafer. This non-contact principle eliminates backside contamination, edge chipping, and surface damage, making it ideal for thin (≤100 μm), fragile, or warped wafers. The ceramic substrate provides high flexural strength (361 MPa for Al₂O₃; up to 550–600 MPa for SiC), low mass, and excellent dimensional stability, ensuring repeatable positioning in high-speed wafer transfer robots.

Note on Materials: Alumina (Al₂O₃) is the most widely used material for ceramic end effectors in semiconductor wafer handling due to its excellent combination of hardness, electrical insulation, chemical stability, and cost-effectiveness. Silicon carbide (SiC) offers higher thermal conductivity, higher hardness, and even better wear resistance for the most demanding applications. While yttria-stabilized zirconia (ZrO₂) offers high fracture toughness at room temperature, it is less commonly used in this application due to its higher density and different thermal expansion characteristics; it may be considered for specific scenarios where exceptional fracture toughness is required. Please consult our technical team for material selection guidance.

Specifications (based on 99.8% Al₂O₃):

Operating Principle:

Compressed air or nitrogen (0.2–0.6 MPa) is supplied through internal channels and exits via precision nozzles. The accelerated airflow creates a low-pressure zone above the end effector (Bernoulli effect), generating lifting force that supports the wafer at a gap of 50–200 μm. No vacuum holes or pads contact the wafer backside.

Applications:

• · Thin wafer (≤50 μm) handling after backside grinding
• · Warped wafer transport (e.g., after CVD or annealing)
• · Solar cell and LED sapphire substrate transfer
• · Cleanroom automation requiring zero particle generation
• · Glass panel handling in display manufacturing

Manufacturing Process:

Ceramic substrate sintered from high-purity powder → 5-axis CNC machining of gas channels and nozzle holes (diameter 0.3–1.0 mm, tolerance ±0.01 mm) → surface lapping to Ra ≤0.4 μm → ultrasonic cleaning → helium leak test (gas channels). No coating required — the bare ceramic surface is chemically inert and non-contaminating.

Quality Control:

• · 100% dimensional inspection (CMM) of nozzle positions, arm length, and flatness
• · Air flow uniformity test: pressure drop ≤5% across all nozzles
• · Leak test: gas channels sealed at 0.6 MPa, no pressure drop over 30 seconds
• · Visual inspection under 20× microscope for micro-cracks or burrs

Advantages over Conventional Contact End Effectors:

• · Zero wafer backside contamination — no mechanical contact
• · No edge chipping or breakage of thin wafers
• · Handles warped wafers (up to 1 mm bow) with stable gap
• · Eliminates vacuum generator and porous chuck maintenance
• · Ceramic construction resists wear and chemical attack

Customization:

• · Available for 200 mm, 300 mm, or custom wafer sizes
• · Gas nozzle patterns: straight, angled, or vortex types
• · Materials: alumina (standard) or silicon carbide (for highest thermal conductivity and wear resistance)
• · Arm length, mounting flange, and gas port location per OEM drawing

Limitations:

The Bernoulli principle implementation (nozzle design, air gap) is beyond the scope of the provided material property tables. The mechanical and thermal properties above strictly follow the supplied datasheets for 99.8% Al₂O₃. No performance degradation of the ceramic under pressurized gas flow is expected based on these material properties. For wafers sensitive to gas flow (e.g., MEMS with fragile structures), gas pressure and nozzle design should be adjusted accordingly.