Optical Glass picture, AF45
 

AF37
Alkali & Arsenic Free Glass

Special Properties

  • Alkali & arsenic free in synthesis*
  • Low sagging
  • Low density glass
  • High chemical and thermal resistivity
  • Low thermal expansion
  • Low shrinkage

Typical Applications

  • Active-Matrix LCD-Displays (AMLCD glass)
  • Common display glass applications
  • Electroluminescent displays
  • Special arsenic free microscope slides
  • Low alkali glass wafers
  • Semiconductor applications

The new alkaline-earth aluminosilicate glass AF37 is characterized by a number of exceptional physical and chemical properties. The speciality glass from Schott is alkali and arsenic free in synthesis, and has a high chemical durability. AF37 offers a high heat resistivity, resulting from the low coefficient of thermal expansion. It features a low shrinkage which is of great importance to many electronics and display applications. AF37 thin glass material is made by using advanced float glass technology. It profits from all advantages of this manufacturing process. Therefore even the natural surfaces of AF 37 show a good flatness and low micro roughness. Often the material can be utilized without an additional mechanical polishing step required, resulting in significant cost savings to the user. AF37 glass has a low thickness tolerance, a good TTV (total thickness variation) and is available even at large dimensions. As a result of its low density, AF37 is relatively light weight, which is an important advantage exceedingly in display applications.


 

Specifications of
AF37 alkali & arsenic free glass*


  Show transmission of AF37

Refractive Index

  • nd = 1,52 (587nm)

Density

  • 2,48 g/cm3

Young's Modulus

  • E = 78 kN/mm2

Coefficient of Thermal Expansion (20-300°C)

  • 3,77 x 10-6/K

Shrinkage

  • ≤ 5 ppm

Viscosity

Viskosität
(dPas)
Temp.
(°C)
Strain Point 14,5 684
Annealing Point 13,0 722
Softening Point 7,6 942
Transformation–
temperature (Tg)
- 711

Chemical Properties

Medium 5%
NaOH
1,3mol/l
10%
NH4F:HF
1,8mol/l
5%
HCL
1,4mol/l


Dl H20
Temp (°C) 95 23 95 95
Reaction time 6h 20min. 24 24
Weight loss
(mg/cm2)
1,3 0,68 0,44 <0,01

Electrical Properties

  • Dielectric constant: 5,5 (1Mhz, 25°C)
  • Loss tangent: 0,19% (1Mhz, 25°C)
  • Volume resistivity:
    1012,4 Ωcm (250°C)
    1010,7 Ωcm (350°C)
  • Temperature Tk 100: 627°C
    (for volume resistivity 10Ωcm)

Nominal standard thickness

  • 0,7mm (+/-0,07)

*Please consider the "Notes on technical specifications"


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