Blank Mask
Glass Mask Structure
| Properties | Type | Soda lime | Quartz |
|---|---|---|---|
| Chemical Composition |
SiO2 | 70 ~ 72% | 100% |
| Na2O + K2O | 13 ~ 15% | ||
| Al2O2 | 1.5 ~ 2.2% | ||
| CaO | 8 ~ 12% | ||
| MgO | 1.5 ~ 4% | ||
| Fe2O2 | 0.07 ~ 0.15% | ||
| Heat Properties |
Coefficient of Thermal Exparsion (50-200) | 81~94×10-7 / (℃) | 6.5×10-7 / (℃) |
| Softening Point(℃) | 740 | 1,683 | |
| Annealing Point(Transformation Temp)(℃) | 562 | 1,215 | |
| Strain Point(℃) | 511 | 1,120 | |
| Optical Properties |
Light Transmittance (%) t=2.3㎜, wavetength=400㎜ 90 90 | 90 | 90/200 |
| Refraction Index nD | 1.52 | 1.46 | |
| Chemical Properties |
Water resistance JIS R-3502 | 0.35 | |
| Acid resistance (㎎/㎠) | 0.002 | 0.000 | |
| Alkaline resistance (㎎/㎠) | 0.042 | 0.032 | |
| Mechanical Properties |
Specific gravity | 2.49 | 2.20 |
| Young’s modulus (㎏/㎟) | 7,300 | 745,000 | |
| Rigidility (㎏/㎟) | 3,020 | 32,000 | |
| Knoop Hardness nu- (㎏/㎟) | 540 | 650 | |
| Electrical Properties |
Cubical resistance at 200℃ | 7.7 | 12.5 |
| Dielectric | 7.5 | 4.0 |
