Glass Wafer

Glass wafer is thin discs of precision glass, made of borosilicate, fused silica, glass, and quartz. It is essential for display engineering and display glass inspection systems. Also, glass wafer is used as a substrate carrier for bonding silicon or other substrates, for Micro Electro Mechanical Systems (MEMs).

Glass wafer is superior to the regular substrate in certain aspects. While being more cost-effective, it has better wrap management and less electrical loss. The glass wafer market is expected to grow further since its related industries like IoT are rapidly expanding.

Unit D 263® T eco AF 32® eco SCHOTT®AF 35 G B 270® i BOROFLOAT® 33
BOROFLOAT® 33 HT		 BOROFLOAT® 40
Optical Properties
Refractive index nD as drawn 1.5230 1.5099 1.5100 1.5229 1.4714 1.486
Luminous Transmittance tvD65 % (at thickness) 91.7
(0.3 mm)		 92.1
(0.4 mm)		 92.1
(0.7mm)		 91.7
(2 mm)		 92.7
(1.1 mm)		 to be checked
Thermal Properties
CTEα 10-6K-1
(20 °C, 300 °C)		 7.2 3.2 3.3 9.4 3.25 4.15
Transformation temperature Tg °C 557 717 712 542 525 589
Mechanical Properties
Densityρ g/cm³ 2.51 2.43 2.40 2.56 2.23 2.31
Young´s modulus E kN/mm² 72.9 74.8 73.9 71.0 64.0 69.0
Chemical Properties
Hydrolytic resistance Class ISO 719 HGB 1 HGB 1 HGB 1 HGB 3 HGB 1 HGB 1
Acid resistance Class DIN 12116 S 3 S 4 S 4 S 2 S 1 S 1
Alkali resistance Class DIN ISO 695 A 2 A 3 A 3 A 1 A 2 A 2
Electrical Properties
Dielectric constant εr
(at ϑ = 25 °C)		 1 GHz 6.4 5.1 5.2 6.7 4.5 to be checked
Dissipation factor tan d
(at ϑ = 25 °C)		 1 GHz 74 · 10-4 35 · 10-4 38 · 10-4 59 · 10-4 51 · 10-4 To be checked