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.
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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
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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
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1737F Glass
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
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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
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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=
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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
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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
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