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AF 32® eco Thin Glass

Alkali-Free* Alumina-Borosilicate Glass

Special Properties

  • Alkali-free glass in synthesis*
  • Low coefficient of thermal expansion
  • Very smooth surfaces
  • High optical transmission
  • Good surface quality and flatness
  • Low micro roughness
  • Can be CNC-cut with diamond tool or laser
  • CTE of the glass matches silicon

Typical Applications

  • MEMS-applications
  • Glass substrates for hybrid-electronics
  • Alkali-free coverslips and microscope slides
  • Semiconductor applications
  • Display technology
  • Laser diode cover glass
  • Photonics research
  • Micro optics
  • Optical filter substrates
  • Alkali-free microscopy glass
  • Cover glass for optical and electronic sensors
  • Interposers
  • Alkali-free glass wafers
  • Glass spacers
  • Micro-arrays
  • Glass windows for optoelectronic components
  • High temperature applications up to 600 °C

The alumina-borosilicate glass AF 32® eco is alkali-free in synthesis*. It is made by the so called "down-draw" manufacturing process. This technology has been developed by SCHOTT and allows the production of very thin glass thicknesses. AF 32® eco offers a remarkably low micro roughness of typical less than 1 nanometer (RMS). A small coefficient of thermal expansion of 3,2 x 10-6, which is close to the CTE of silicon, opens up a wide range of glass wafer applications in the semiconductor industry. But AF 32 eco glass also is a good choice for micro optics- and micro-electro-mechanical systems (MEMS applications). Not least in science and research there are numerous fields of applications AF32 glass material can be used for. We manufacture alkali-free microscope slides, coverslips, glass wafer components and various optics for photonics research based on this high quality thin glass. AF 32® can be precision-cut with diamond tools on CNC-machines or it can be processed by laser-cutting. The glass offers a high light transmittance from the visible to the infrared wavelength range up to approximately 2500 nm. This allows the use of AF 32® eco glass for a wide range of optical applications. Especially the smaller glass thicknesses feature quite a good optical transmissivity even in the UVB-wavelength range.

The "eco" in the glass brand name stands for the production with eco-friendly refining agents SCHOTT uses for the melting of all AF 32 glass thicknesses.

To request a window, substrate, wafer or any kind of optics made of AF 32® eco alkali-free* glass with individual dimensions, please click the button below:

 

Request for Quotation

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*Caused by low alkali traces in the raw materials and resulting from the production process according to SCHOTT an alkali content of 0,2 weight per cent of the glass might be possible.

 

Specifications

 

Light Transmission of SCHOTT AF 32® eco glass

Click to enlarge light transmission curve of SCHOTT AF 32® eco glass

Display transmission spectrum of AF 32® eco

 

Optical Properties

  • Abbe number: ve= 62,4

AF 32 eco glass, Index of Refraction

Description

Wavelength (nm)

Refractive Index

ng
436
1,5200
nF'
480
1,5161
nF
486
1,5156
ne
546
1,5119
nd
587,5
1,5100
nD
589,3
1,5099
nC'
644
1,5079
nC
656
1,5075

Mechanical Properties

  • Density: 2,43 g/cm3
  • Young's modulus E: 74,8 kN/mm2
  • Stress optical coefficient C:
    3,1 x (1,02 x 10-12 m2/N)
  • Poisson's ratio μ: 0,238
  • Torsion modulus G: 30,2 kN/mm2
  • Knoop hardness HK0,1/20: 490
  • Vickers hardness HV0,2/25: 540

Thermal Properties

  • Coefficient of thermal expansion :
    3,2 x 10-6/K (20 °C ; 300 °C)
  • Viscosities:
    • Softening Point (107,6 dPa): 970 °C
    • Annealing Point (1013 dPa): 731 °C
    • Strain Point (1014,5 dPa): 686 °C
  • Transformation temperature Tg: 717 °C

Chemical Properties

  • Hydrolytic resistance according to DIN ISO 719:
    • Resistance class HGB 1
    • Equivalent of Alkali (Na2O) per g of glass grains: 10 μg/g
  • Acid resistance according to DIN 12 116:
    • Resistance class 4
    • Half surface weight loss after 6 h:
      >60 mg/dm2
  • Alkali resistance according to DIN ISO 695:
    • Resistance class A3
    • Surface weight loss after 3 h:
      210 mg/dm

Electrical Properties

  • Dielectric constant εr:
    • 5,1 (1 MHz)
    • 5,1 (1 GHz)
    • 5,1 (5 GHz)
  • Dielectric loss factor(tan δ at 25 °C):
    • 28 x 10-4 (1 MHz)
    • 35 x 10-4 (1 GHz)
    • 49 x 10-4 (5 GHz)
  • Electric volume resistivity ρD:
    • 7,9 x 1011 Ω x cm (250 °C)
    • 1,1 x 1010 Ω x cm (350 °C)
    • 1,5 x 108 Ω x cm (500 °C)

Available AF 32® eco thicknesses

(Click on a glass thickness to request it)

Glass thickness
(mm)

Tolerance

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0,100 ±0,015
0,200 ±0,020
0,300 ±0,020
0,400 ±0,020
0,500 ±0,030

 

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