Application of iolite ceramics
1. Lithography machine square mirror
As one of the core units of the lithography
machine, the motion accuracy of the ultra-precision workpiece table will
directly affect the resolution of the lithography machine. As the core
component of the workpiece, the square mirror provides a guarantee for the
accuracy and lithography efficiency of the workpiece. The thermal load on the
square mirror during operation is constantly changing due to the heat flow in
the working space, requiring the deformation to change with temperature as
little as possible, and the distortion caused by its operation at higher
accelerations and speeds must be corrected. Therefore, in order to meet the
requirements of lithography accuracy, the thermal expansion coefficient of the
square mirror material should achieve near-zero expansion at the working
temperature, and it should also have good mechanical properties. Iolite
ceramics are ideal square mirror materials for lithography machines due to
their low thermal expansion coefficient, excellent mechanical properties and
low density. ASML has realized the mature application and promotion of iolite
ceramics in the mobile stage parts of lithography machines.
2. Optical mirrors for optical
communication
Iolite has the characteristics of low
thermal expansion, high mechanical strength and high rigidity, long-term
dimensional stability, and radiation resistance, and can be applied to space
optical communications. Sony CSL has adopted Kyocera cordierite ceramic mirrors
for small low-earth orbit safety laser communication terminals.
3. Refractory materials
Due to its low coefficient of thermal
expansion, iolite ceramics are often used as ceramic encapsulation materials
and kiln furniture during kiln use. At the same time, iolite ceramics have the
characteristics of low density, low thermal conductivity and good stability at
high temperatures, and can also be applied to heat exchange devices with rapid
temperature changes, such as heat-resistant pots. There are a large number of
voids in the middle of the six-membered ring of the iolite crystal and in the middle
of the adjacent six-membered ring, and this loose crystal structure makes it
have a very low coefficient of thermal expansion, which can be used as a lost
foam refractory coating in the casting process, improving the accuracy of the
casting.
