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Wafer Edge Chipping Wafer Thinning
Wafer Edge Chipping – Causes & Solutions
| Cause | Details | Solutions / Countermeasures |
|---|---|---|
| Mechanical Grinding Stress | - High stress at wafer edge during wheel contact - Coarse wheel / aggressive feed → deep cracks - Dull wheel → higher pressure, brittle fracture | - Use multi-step grinding (rough → fine) - Reduce feed rate and spindle speed - Regular wheel dressing & timely replacement |
| Wafer Edge Quality | - Poor edge grinding → stress points - Thin wafers (<200 μm) or large diameter (12") → weak rigidity - Incoming wafer edges with defects/particles | - Improve edge grinding quality (smooth, rounded edge) - Pre-inspection of incoming wafers - Laser grooving or reinforcement |
| Chuck Table Issues | - Uneven or insufficient vacuum adsorption - Chuck surface not flat or mismatched size | - Clean and unclog vacuum holes - Regularly measure chuck flatness - Ensure proper chuck-to-wafer match |
| Handling & Transfer | - Robot arm contact with wafer edge - Collisions during cleaning or cassette loading | - Calibrate robot picker for precise, soft handling - Train operators on careful wafer handling - Use dedicated thin-wafer carriers |
| Process Limitations (Ultra-thin Wafers) | - Wafers <100 μm prone to warpage and edge chipping | - Temporary bonding with rigid carrier - Post-grind wet or plasma etch for stress relief |
CERAMERIC SEMIXICON
THE WAFER CHUCK TABLE EXPERT
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