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AF 32® eco Thin Glass

Alkali-Free* Alumina-Borosilicate Glass

Special Properties

  • Alkali-free 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
  • Substrate for hybrid-electronics
  • Alkali-free cover slip
  • Semiconductor applications
  • Display technology
  • Laser diode cover glass
  • Photonics research
  • Micro optics
  • Alkali-free microscopy glass
  • Cover for optical and electronic sensors
  • Interposer
  • Alkali free glass wafer
  • Glass spacer
  • Micro-arrays
  • High temperature applications up to 600 °C

The alumina-borosilicate glass AF 32® eco is alkali-free* in synthesis. The glass is made by the so called "down-draw" manufacturing process. This technology allows the production of very thin glass thicknesses and a very low micro roughness of typical < 1 nanometer (RMS). A low coefficient of thermal expansion of 3,2 x 10-6 which matches 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 MEMS applications (Micro-Electro-Mechanical Systems). Not least in science and research there are numerous fields of applications AF32 glass material is used for. For example, we manufacture special microscope slides, cover slips and several optics of this high quality alkali-free* thin glass. A high light transmittance from the visible to the infrared wavelength range up to approx. 2500 nm allows the use of AF 32® eco in many interesting optical applications. Further, the thinner 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 used for the melting this glass material.

To request a window, substrate or a wafer 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 might be possible.

Specifications

 

Transmission of SCHOTT AF 32® eco

Click to enlarge Transmission curve of AF 32® eco

Display transmission spectrum of AF 32® eco


Optical Properties

  • Abbe number: ve= 62,4

AF 32 eco, 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 Thicknesses

(Click on a thickness to request it)

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"