AF37

Special Properties

• Alkali & arsenic-free in the synthesis
• Low sagging
• Low-density glass
• High chemical and thermal resistance
• Low thermal expansion
• Low shrinkage

Typical Applications

• Active-Matrix LCD-Displays (AMLCD glass)
• Display glass applications
• Electroluminescence displays
• Arsenic-free microscope slides
• Alkali free glass wafers
• Semiconductor applications

Related glass types

• 1737F (boro-aluminosilicate glass)
• EAGLE²⁰⁰⁰ (boro-aluminosilicate glass)
• AF 32^® eco (alkali-free alumina-borosilicate thin glass)
• AF 45 (modified borosilicate display glass)
• 7059 / 7059F (low alkali barium-borosilicate glass)

Numerous exceptional physical and chemical properties characterize the alkaline-earth aluminosilicate glass AF37. The specialty glass from SCHOTT is alkali and arsenic-free in synthesis and has high chemical durability. Due to the low coefficient of thermal expansion of AF37 glass, it offers high heat resistance. It features low shrinkage, which is of great importance to many electronics and display applications. The thin glass material is made using advanced float glass technology. It profits from all the advantages of this manufacturing process. Therefore, the natural surfaces of AF 37 already show excellent flatness and low micro-roughness. The material can often be utilized without an additional mechanical polishing step, resulting in significant cost savings for the user. AF37 glass has a small 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 lightweight, which is a significant advantage for display applications. For further information, please contact us.

To request windows or substrates made of our AF 37 arsenic-free glass at a custom size, please click the button below.

 

The production of AF37 glass was discontinued shortly after its market launch. Unfortunately, this material is no longer available. You can find alkali-free alternatives above under the headline "Related glass types".

 

Specifications

 

Nominal standard thickness

• 0,7 mm (+/-0,07)

Optical Properties

• Display the transmission spectrum of AF37
• UV-Transmission of AF37
• Birefringence constant:
  3,18 × 10^-6 mm²/N (588 nm ; 21 C°)
• n_d = 1,52 (587 nm)

Mechanical properties

• Density: 2,48 g/cm³
• Young's Modulus: 78 kN/mm²
• Poisson Ratio: 0,24
• Vickers Hardness: 640 (2 N / 25 sec)

Thermal Properties

• Coefficient of thermal expansion:
  3,77 × 10^-6/ °C (20-300 °C)
• Shrinkage:
  ≤ 5 ppm (Hold 1 h at 400°C, ramping 2,5 °C/min.)
• Transformation temperature Tg: 711 °C
• Viscosities:
  • Strain point (10^14,5 dPa): 684 °C
  • Annealing point (10¹³ dPa): 722 °C
  • Softening point (10^7,6 dPa): 942 °C
  • Working point (10⁴ dPa): 1263 °C
• Heat conductivity: 1,12 W/mK (90 °C)
• Mean specific heat capacity: 0,78 kJ/kgK (20-100 °C)

Electrical Properties

• Dielectric constant: 5,5 (1 MHz ; 25 °C)
• Loss tangent: 0,19 % (1 MHz ; 25 °C)
• Volume resistivity:
  • 10^12,4 Ωcm (250 °C)
  • 10^10,7 Ωcm (350 °C)
• Temperature Tk 100: 627 °C
  (for volume resistivity of 10⁸ Ωcm)

Chemical Properties

Medium	5 % NaOH 1,3 mol/l	10 % NH4F:HF 1,8 mol/l	5 % HCL 1,4 mol/l	Dl H20
Temp (°C)	95	23	95	95
Reaction time	6 h	20 min	24 h	24 h
Weight loss (mg/cm2)	1,3	0,68	0,44	< 0,01

All given details and specifications are mean reference values and are not guaranteed. Also, please consider our "Notes on technical specifications."

© 1994 – 2024 Präzisions Glas & Optik GmbH

Last update: April 17, 2024