Capabilities
Precision Drilling & Slotting
CNC diamond-core drilling, ultrasonic drilling, and slotting for quartz, sapphire, and ceramics, with hole size and positional requirements reviewed by drawing.
Precision Drilling & Slotting of Brittle Non-Metallic Materials
Drilling and slotting of fused quartz, sapphire, and technical ceramics presents unique challenges: radial cracking, chipping at hole entry/exit, taper error, and heat accumulation. Tuguan Semiconductor reviews the drilling route for each material-tool combination to manage edge quality and positional requirements.
Drilling Methods
Diamond Core Drilling
The primary method for holes ≥ 0.8 mm diameter in all ceramic and quartz grades. Hollow diamond-plated cores remove material annularly, minimizing cutting force and heat.
| Specification | Standard | Precision |
|---|---|---|
| Hole diameter range | Reviewed by material and wall thickness | Reviewed by material and wall thickness |
| Diameter tolerance | Per drawing | Reviewed for critical dimensions |
| Positional accuracy | Per drawing | Reviewed for critical dimensions |
| Roundness | Per drawing | Reviewed by inspection method |
| Taper | Reviewed by depth and drilling route | Reviewed by depth and drilling route |
| Exit chipping | Reviewed by edge-quality requirement | Reviewed by edge-quality requirement |
Key practices:
- Peck drilling cycles with DI water flood cooling prevent heat accumulation
- Dedicated entry/exit backing plates prevent breakout chipping on exit side
- In-feed rates calibrated to material hardness and drill diameter
Ultrasonic Drilling
For small holes, very hard materials such as sapphire or SiC, or tight hole arrays, ultrasonic-assisted drilling can be reviewed to reduce cutting force.
| Specification | Value |
|---|---|
| Min hole diameter | Reviewed by material and thickness |
| Max depth-to-diameter ratio | Reviewed by geometry |
| Surface finish inside bore | Specified per application |
| Subsurface damage | Reviewed by process route |
| Taper | Reviewed by hole depth |
Advantages over conventional drilling:
- Cutting-force reduction for thin-wall parts can be reviewed by material and geometry
- Exit chipping requirements should be specified before production
- Depth-to-diameter requirements are reviewed case by case
Slotting & Milling
CNC Diamond Slotting
Straight and contoured slots in quartz and ceramics are machined using diamond-dressed slitting wheels or end mills on CNC machining centers.
| Feature | Capability |
|---|---|
| Min slot width | Reviewed by material and tool access |
| Slot width tolerance | Per drawing |
| Slot depth tolerance | Per drawing |
| Surface roughness (slot walls) | Specified per application |
| Corner radius (internal) | Reviewed by tool access |
| Max slot depth | Reviewed by width and material |
Typical slotted features:
- Gas distribution slots in showerheads and injectors
- Anti-rotation slots and keyways
- Wafer slot arrays in boats (50–200 slots at precise pitch)
- Notches and flats for orientation features
Hole Arrays & Multi-Hole Patterns
Precision multi-hole patterns (showerheads, gas injectors, carrier plates) are reviewed from CNC drilling programs and fixture strategy.
| Specification | Value |
|---|---|
| Hole pitch repeatability | Per CAD pattern and inspection scope |
| Max holes per part | Reviewed by part size and inspection scope |
| Hole diameter uniformity (array) | Per drawing |
| Positional grid error | Per inspection method |
Process note: Multi-hole plate fixturing is reviewed to reduce part shift between holes and support the intended gas-flow pattern.
Material Drilling Guide
| Material | Preferred Method | Min Hole Ø | Notes |
|---|---|---|---|
| Natural fused quartz | Diamond core | 0.8 mm | Low hardness; fast drilling |
| Synthetic fused silica | Diamond core | 0.8 mm | Same as natural quartz |
| Sapphire | Ultrasonic + diamond | 0.3 mm | Hard and brittle; requires US assist |
| Alumina 99.5% | Diamond core | 0.8 mm | Moderate; standard coolant |
| Silicon nitride | Diamond core + US | 0.5 mm | High fracture toughness |
| Silicon carbide | Diamond core + US | 1.0 mm | Hardest ceramic; slow feed |
| Boron nitride | Carbide drill | 0.5 mm | Soft; standard tooling acceptable |
Quality Verification
Drilled and slotted feature inspection can be agreed against drawing requirements:
- CMM measurement of hole position, diameter, and roundness
- Borescope inspection for bore surface condition on deep holes
- Surface profilometer for bore roughness on precision components
- Go/no-go gauges for production lot diameter verification
- Exit chipping measurement under optical microscope (50×)