Granite platforms / bases have become an indispensable core requirement for high-tech manufacturing for the following reasons
High-end manufacturing (semiconductor lithography, CMM, ultra-precision machining, optical inspection, aerospace metrology) demands extremely strict long-term stability of nano/micronlevel reference bases. Cast iron, steel, and resin concrete all have inherent shortcomings; relying on a natural mineral structure formed over billions of years, granite possesses six unique physical and chemical, making it the only substrate capable of maintaining ultra-high precision reference bases over the long term.
Precision granite platforms
Granite bases for semiconductor equipment
I. Billions years of natural aging, zero internal stress, permanent zero deformation (the most core advantage)
Ordinary metals (cast iron, steel), castings, and resin concrete possess significant residual internal after processing. Over years of use, this stress is slowly released, causing the table surface to slowly warp and the flatness to drift, directly invalidating the reference base…
Gran undergoes millions of years of geological compaction and thermal cycles deep underground, completely releasing its internal stress naturally; after precision machining and shaping, it exhibits no creep or slow plastic deformation:
15 years of service, the annual flatness drift is only 0.1~0.3μm;
CMM and lithography machine reference tables can stably maintain 00-grade ultra-high flatness for decades without frequent major overhauls or recalibrations.
Once the reference base deforms in high-tech manufacturing, all micron/nanometerlevel machining and measurement data become invalid, which is an unfixable flaw of metal materials.
II. Extremely low coefficient of thermal expansion, almost no dimensional deviation from temperature fluctuations
changes are the biggest precision killers for equipment:
Steel thermal expansion coefficient: ≈6.5~12μm/m・℃; a 5℃ workshop temperature difference day and night will cause tens of micrometers of error, directly exceeding aerospace and semiconductor tolerances;
High-end black granite: only 2~4μm/m・℃;-tier lithography-specific granite is as low as 0.5μm/m・℃.
Semiconductor EUV lithography, wafer dicing, and optical inspection environments allow ±0.1℃ fluctuations. Granite bases can control thermal drift at the 0.1nm level, ensuring stable exposure and wafer positioning accuracy for nano-processes.
. Superb vibration damping, rapid absorption of vibrations, elimination of micron-level disturbances
The micro-pore structure of granite crystals possesses natural high-damping characteristics, with vibration performance far exceeding cast iron (3~10 times better):
Isolating external vibrations: Micro-vibrations from the ground caused by workshop cranes, air compressors, personnel walking are rapidly absorbed;
Suppressing equipment self-vibration: Vibrations from high-speed movement of machine tool spindles, motors, and air bearings are rapidly attenuated;
value:
Wafer dicing: Vibration amplitude <2μm, with cutting edge roughness meeting chip packaging standards;
CMM probes: Instant stability after touching the workpiece, significantly improving repeatability;
Optical platforms: Interference and laser detection are free from ripple interference, ensuring imaging/measurement is free from noise errors.
IV. High hardness and wear resistance, rust-proof, chemical corrosion resistant, maintains reference flatness over the long term
Ultra-high wear resistance: Mohs hardness is far higher than cast iron and aluminum; measuring tools and workpieces are not easily scratched by long-term dragging, and the flatness of the table surface does not degrade over the years; cast iron platforms develop numerous scratches after 2-3 years of use, causing the reference to fail and requiring regrinding.
Completely rust-proof: No metal oxidation reaction, resistant to cutting fluids, coolants, moisture, and acid-alkali mists; steel bases must be painted or electroplated, and once the coating wears off, rust bumps directly destroy the precision reference.
Extremely low water absorption: Dense granite has a water absorption rate <0.01%, will not swell from water absorption, and will not deform due to oil penetration, ensuring stability and durability in harsh workshop conditions.
V. Non-magnetic, suitable for semiconductor and precision electromagnetic testing scenarios
Granite contains no ferromagnetic minerals, is completely non-magnetic, and produces no magnetization effect:
Semiconductor wafer, magnetic head, and sensor processing: Will not interfere with magnetic field positioning, electronic sensors, or grating scale readings;
Electromagnetic testing, precision magnetic fixtures: Will not produce magnetic attraction or magnetic field distortion;
Cast iron and steel have inherent magnetism, which interferes with the processing and testing of nano-scale electronic components, making them completely unsuitable for semiconductor production lines.
VI. High rigidity, stable self-weight, resistant to load-induced bending deformation
Granite has a high Young’s modulus, high density, and sufficient self-weight:
When supporting heavy-duty tooling and large aerospace components, the table surface experiences minimal bending deformation;
Self-weight provides natural counterweighting, ensuring no resonance or risk of overturning during high-speed equipment movement;
Compared to lightweight aluminum alloy bases, which are easily deflected under heavy loads, granite cannot be used for large-stroke precision measurement and machining equipment.
Mainstream essential application scenarios (verifying irreplaceability)
Semiconductor manufacturing: EUV/DUV lithography machine worktables, wafer dicing machines, chip packaging inspection bases (the only choice for nano-scale precision);
Precision metrology: Coordinate measuring machines (CMM), laser interferometers, profile projectors, Grade 000 reference surface plates;
Ultra-precision machining: Optical grinders, diamond lathes, mold mirror-surface CNC machine bases;
Optical / laser equipment: Interferometers, spectrometers, femtosecond laser processing optical platforms;
Aerospace: High-precision inspection tooling for turbine blades and aircraft structural components;
New energy precision equipment: Lithium battery electrode inspection, silicon carbide substrate cutting platforms.
