Medium-High Purity Clear Quartz Glass EN08

EN08 is mechanically drawn electrically fused clear quartz glass. It uses natural quartz as raw material with SiO2 ≥99.98%. It is available in tube, rod and plate.

In semiconductor and photovoltaic (PV) industry, the tube, rod and plate are used in quartz washing tank and quartz boat for wafer cleaning and so on where the working temperature is below 800℃. Due to the elevated sodium (Na), EN08 glass can not be employed in high-temperature semiconductor and photovoltaic (PV) industry where the temperature is over 800℃, or the sodium will cause the glass devitrification.

In lighting: because of its medium-high purity, EN08 has an excellent transmission in both deep UV range of 100-200nm wavelength and UVC range of 200-280nm wavelength. By vacuum annealing, the OH of EN08 can be lowered below 20ppm. So this item is a good material in ozone producing and UVC disinfection field.

The glass tube can be supplied in the range between 6mm-40mm outer diameter. The rod is available between 1mm-25mm outer diameter. The plate is available of maximum size 2000x800x5-7mm.

 

Main application is as follows:

Typical trace elements and OH content in quartz glass (ppm by weight oxide)

Type OH Application
EN08UB OH≤150ppm sleeve (jacket) of low pressure ozone producing UV germicidal lamps and ozone free UVC germicidal lamps, fiber optics.
EN08EB OH≤20ppm low temperature semiconductor and PV industry, lamps tube of low pressure ozone producing UV germicidal lamps.

 

Chemical Composition:

unit:ppm

Al Li K Na Ca Fe Ti Mg Cu B SiO2
EN08 16.5 2.0 0.63 3.69 1.33 0.61 1.4 0.14 0.03 0.5

 

Hydroxyl (OH) Content:

UB NB EB SB
EN08 ≤150 ≤30 ≤20 no

 

Thermal Properties:

coefficient of expansion 25-300℃ cm/cm.℃ 5.5 x 10-7
thermal conductivity 20℃ W/m.℃ 1.4
specific heat 20℃ J/Kg.℃ 670
softening point 1680
strain point 1110
annealing point 1200
max.working temperature
continuous
short-term
1160
1300

 

Mechanical Properties:

Young’s modulus Pa 7.2 x 1010
density kg/m2 2.2 x 103
tensile strength Pa 4.8 x 107
compressive strength Pa >1.1 x 109
Poisson’s ratio 0.17

 

Electrical Properties:

loss tangent 20℃ and 1MHz <2 x 10-4
dielectric constant 20℃ and 1MHz 3.75
resistivity 350℃ ohm.cm 7.0 x 109
insulation strength V/m 5.0 x 107

 

Optical Properties:

index of refraction 1.459
transmittance wall thickness 1.5mm see below form
nm 185 200 220 245 254 320 340 500 800
% 64.8 67.5 84.3 89.8 90.4 92.3 92.4 92.5 92.5

 

EN08 Graph