Optical glass disks, flat glass, precision polished glass
Properties of Optical Glasses
A variety of glasses are available from Valley Design. This is an outline of optical, mechanical, thermal and electric properties of the most commonly requested glass types: Soda Lime, Pyrex, Borosilicate and Borofloat glasses.
Various windows, plates and disks that can be optically polished to better than 0.5 microinches (20/10), are excellent as substrates and also in semiconductor form for applications such as: resistor networks, thin and thick film microelectronics, vacuum vapor and sputtering depositions, photomasks, electro optics, semiconductor monitor wafers and other precision optical components.
Soda Lime Glass
7740-Pyrex, Borofloat Glass, Borosilicate Glass
- Low coefficient of thermal expansion
- High operating temperature
- Chemical durability
- Anodically bondable to Silicon
- Properties of 7740- Pyrex
1737F-Alkaline Earth Aluminosilicate Glass-(replaces 7509 glass)
- High operating temperature (strain point 666°C)
- Low coefficient of thermal expansion
- Low thermal shrinkage
- Properties of 1737F
0211-Alkali Zinc Borosilicate Glass
- Transmittance in the visible and near infrared spectrums
- Soda content is half that of Soda Lime Glass
- Maximum thickness is 0.3 mm
- Properties of 0211
7070-Lithium Potash Borosilicate Glass
- Relatively high operating temperature
- Anodically bondable to Silicon
- Microwave window applications
- Low coefficient of thermal expansion
- Excellent hermetic sealing characteristics
- Properties of 7070
BK-7 Borosilicate Crown Glass
- Most popular optical glass
- Excellent transmission (350nm to 2000nm)
- Low index of refraction
- Properties of BK-7
AF-45 Modified Borosilicate Glass
- Alkali-free in synthesis
- Low coefficient of thermal expansion
- Excellent thermal resistance
- High luminous transmission
- Properties of AF-45
D-263 Borosilicate Glass
All data is subject to normal manufacturing variations and is provided for reference purposes only. Customers are responsible for selecting the suitability of material for their intended application.
Soda Lime Glass
Principal Uses
Mirrors, microslides, printed circuit substrates and electronic applications
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.44 g/cm³
Thermal Coefficient of Expansion: (0/300 °C)
8.6 x 10-6/°C
Strain Point: 490°C/ 914°F
Annealing Range:480°C-575°C/896°F-1067°F
Softening Point: 575°C/1067°F
Optical Properties
Refractive Index (l=435): 1.523
(l=645)=1.513
Optical transmission
Chemical Properties
Hydrolytic resistance: class 3
Electrical Properties
Dielectric Constant: E= 7.75
Pyrex 7740
Principal Uses
Filter lens, sheet glass, tubing
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.23 g/cm³
Thermal Coefficient of Expansion (0/300 °C):
32.5 x 10-7/°C
Strain Point: 510°C/950°F
Annealing Point: 560°C/1040°F
Softening Point: 821°C/1509.8°F
Optical Properties
Refractive Index(l=589.3nm): 1.473
Optical transmission
Chemical Properties
Hydrolytic resistance: class 1
Acid resistance: class 1
Alkali resistance: class 2
Electrical Properties
Dielectric Constant: E= 4.6
Pyrex 7740
Principal Uses
Filter lens, sheet glass, tubing
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.23 g/cm³
Thermal Coefficient of Expansion (0/300 °C):
32.5 x 10-7/°C
Strain Point: 510°C/950°F
Annealing Point: 560°C/1040°F
Softening Point: 821°C/1509.8°F
Optical Properties
Refractive Index(l=589.3nm): 1.473
Optical transmission
Chemical Properties
Hydrolytic resistance: class 1
Acid resistance: class 1
Alkali resistance: class 2
Electrical Properties
Dielectric Constant: E= 4.6
Principal Use(s)
Substrates for flat panel displays
Thermal / Mechanical Properties
Density (at 25º C/77 ºF):
2.54 g/cm³
Thermal Coefficient of Expansion (0/300 °C; 32/572 °F):
37.6 x 10-7/°C;
21 x 10-7/°F
Strain Point: 666°C/1231°F
Annealing Point:721°C/1330°F
Softening Point:975°C/1787°F
Optical Properties
Refractive Index (l=656.3nm): 1.5160
(l=435.8nm): 1.5290
Optical transmission
Electrical Properties
Dielectric Constant: E= 5.7
7070
Principal Use(s)
Low loss electrical applications
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.13 g/cm³
Thermal Coefficient of Expansion (0/300 °C; 32/572 °F):
32 x 10-7/°C;
17.7 x 10-7/°F
Strain Point: 456°C/ 853°F
Annealing Point: 496°C/925°F
Softening Point: NOT MEASURABLE
Optical Properties
Refractive Index (l=589,3nm): 1.469
Chemical Properties
Hydrolytic resistance: class 2
Acid resistance: class 2
Electrical Properties
Dielectric Constant: E= 4.0
BK7
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.51 g/cm³
Thermal Coefficient of Expansion (20/300 °C):
7.0 x 10-6/°C
Strain Point:°C/ °F
Annealing Point:°C/ °F
Softening Point:°C/ °F
Optical Properties
Refractive Index (l=582.1nm): 1.509
Optical transmission
Chemical Properties
Hydrolytic resistance: class 2
Acid resistance: class 1
Alkali resistance: class 2
Electrical Properties
Dielectric Constant: E=
AF45
Principal Uses
LCD, solar cells, hybrid circuits, CCD
covers, electroluminescent displays
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.72 g/cm³
Thermal Coefficient of Expansion (20/300 °C):
4.5 x 10-6/°C
Strain Point: 627°C/1161°F
Annealing Point: 663°C/1225°F
Softening Point: 883°C/1621°F
Optical Properties
Refractive Index(l=588nm): 1.5255
Optical transmission
Electrical Properties
Dielectric Constant: E= 6.2
D263
Principal Use(s)
Touch control panels, LCD, solar cells,
electroluminescent displays
Thermal / Mechanical Properties
Density (at 20º C/68 ºF):
2.51 g/cm³
Thermal Coefficient of Expansion (20/300 °C; 68/572 °F): 8.6 x 10 -6/°C
Strain Point: 529°C/984°F
Annealing Point: 557°C/1035°F
Softening Point: 736°C/1357°F
Optical Properties
Refractive Index (l=546nm): 1.5255
(l=588nm): 1.5230
Optical transmission
Chemical Properties
Hydrolytic resistance: class 1
Electrical Properties
Dielectric Constant: E= 6.7