Mechanical Properties
(1) Bending Strength
Columnar crystal silicon shows superior mechanical strength because it is produced by releasing the inner strain. In the bending test, columnar crystal silicon shows higher bending strength than single crystal and poly-crystalline silicon.
(2) Mechanical Strength at High Temperature
Columnar crystal silicon also shows very stable mechanical strength over a wide temperature range. In the high temperature creep test, its displacement was below 0.3%. It can be applied in various application fields.
High Temperature Creep Test Results
| Temperature | Load(kgf/cm2) | Displacement(%)* |
|---|---|---|
| 1200℃ | 8 | <0.050 |
| 16 | 0.250 | |
| 1300℃ | 16> | 0.265 |
*:After 360 minutes keeping
(3) Hardness and Fracture Toughness Value
Columnar crystal silicon shows quite similar Vickers hardness and fracture toughness value to single crystal silicon. From these results, it can be said that columnar crystal silicon has almost the same processing characteristic as single crystal silicon. We can apply various machining and processing techniques which are used in single crystal silicon processing.
| Vickers Hardness(HV) | Fracture Toughness Value(MPam1/2) | |
|---|---|---|
| Single Crystal Silicon | 1053 | 0.4 |
| Columnar Crystal Silicon | 1046 | 0.4 |
*1:Measurement Method:JIS R1607 IF Method
*2:Load:300g
(4) Machinability
Columnar crystal silicon shows good machinability. We can machine it with less chipping. The results after machining are very similar to those of single crystal silicon.
Appearance of Hole Drilling
