Controlled expansion alloy wafers up to 12” diameter supplied as lapped, polished or polished and metallized wafers, expansion matched to compound semiconductor materials.
Our alloy wafers are used for:
- Medium and high brightness LED
- Photovoltaic cells
Alloys chosen are typically CE6F and CE7F, and these are used to replace sapphire – GaAs.
Advantages of CE6F controlled expansion alloy
- CTE matching of compound semiconductor materials
- Superior thermal and electrical properties
- Enhanced reliability
- Low cost
| Material | CE6F |
|---|---|
| Diameter | 100 mm +/-0.05 mm |
| Flat | 32 mm +/-0.02 mm |
| Chamfer | 220 μ +/-50 μ |
| Thickness | 750 μ +/- 20 μ |
| TTV | <5 μ |
| Surface | Polished both sides Ra < 20 nm |
| Bow weight | < 20 μ |
| Property | Ge | Si | GaAs | Sapphire | CE6 |
|---|---|---|---|---|---|
| CTE 25–300ºC | 5.8 | 3 | 6.8 | 5.8 | 6.2 |
| Density g/cc | 5.32 | 2.3 | 5.3 | 4.0 | 2.45 |
| Young's Modulus, GPa | 130 | 112 | 85 | 350 | 130 |
| Thermal conductivity, W/mK | 64 | 150 | 40 | 35 | 110 |
| Electrical resistivity, μΩ.cm | 50 | 105 | 107 | 1014 | 115 |
| Plateability | Good | Poor | Poor | Poor | Good |
| Machinability (CNC/EDM) | Poor | Poor | Poor | Poor | Good |