Sapphire: Properties, Uses and Processing Examples

This page introduces the sapphire polishing process performed at TDC.

For a detailed explanation of TDC’s polishing process, please check the “Polishing service” page.

Sapphire Polishing at TDC

At TDC, we are good at polishing sapphire with our own technology development and polishing technology that we have cultivated so far.

We can handle the polishing of parts and materials using sapphire, which requires high precision.

For a detailed explanation of TDC’s polishing process, please check the “Polishing service” page.

Sapphire polishing possible with TDC

At TDC, high-precision polishing is possible by using the following polishing methods.

Lapping, lapping polishing, polishing polishing (mirror polishing)

Polish the sapphire glass by pouring abrasive grains into the lapping machine and applying pressure.

Lapping is an important polishing method that is the key to precision and quality, as it removes large scratches and also adjusts dimensions in this process.
・It is possible to handle up to about dia.600 mm.
・Thickness accuracy < +-0.001mm, flatness < 0.001mm, parallelism < +-0.001mm, surface roughness < Ra1nm.

For more information about TDC’s lapping and polishing, check “About Lapping and Polishing” paeg.

For more information about TDC’s lapping and polishing, check “What is Polishing?” paeg.

Features of TDC’s sapphire polishing process

Sapphire polishing at TDC has the following strengths and characteristics.

• High-precision polishing technology
  TDC’s precision polishing technology enables ultra-high-precision metal precision processing at the micron and nano level by controlling the removal amount. Compared to processing methods such as cutting and grinding, it is possible to handle any shape without applying a load to the object.
• Short delivery time and express service available
  By owning more than 100 polishing machines, we can achieve short delivery times even for large lots and complex processing. If you are in a hurry, we will also respond to consultation with “express response”.
• Small Lot
  Please feel free to contact us for small lot orders starting from 1 unit and prototype production.
• Owns over 100 abundant processing machines
  TDC owns more than 100 polishing machines such as lapping machines and surface grinders. We also have various processing machines such as machining centers and milling machines, so we can handle all kinds of processing.
• About half of the polishing equipment is manufactured in-house
  About half of the more than 100 polishing machines are made in-house, realizing “low-cost” and “high-quality” manufacturing.

TDC’s sapphire polishing process example

Here are some examples of typical sapphire polishing at TDC.

Sapphire polishing example 1, Sapphire roll inner and outer diameter mirror finishing

This item has a mirror finish with well controlled dimensions of inner and outer diameters. Mirror polishing of the inner diameter is possible with our original equipment.

• Material : Sapphire
• Size : dia.100 x dia.50 x L100mm
• Machining details : inner and outer diameter mirror finish
• Accurac y : Ra1nm or less with a Mirror finish

Sapphire Polishing Case 2, Sapphire Bonded Substrate Polishing

Polishing processing of bonded substrates of sapphire and various materials. Mirror finish while controlling the thickness.

• Material: Sapphire bonded substrate (compatible with various bonded substrates)
• Size: Various sizes available
• Processing details: Submicron-level thickness control and mirror finish
• Accuracy: Ra1nm or less, plate thickness tolerance +-0.001mm or less

What is Sapphire

When we hear the word “sapphire”, we generally imagine gemstones, but it is one of the materials that is widely used as an industrial material because of its high hardness, heat resistance, and transparency.

Generally, when used in industrial materials, it is called “sapphire glass”.

Features of sapphire glass

Sapphire glass has the following characteristics:

• Hard and scratch resistant
  … Sapphire glass has a hardness of 9, second only to diamond, which has a hardness of 10. Therefore, sapphire glass can only be processed with a polishing machine that contains diamonds.
• Resistant to heat
  … While ordinary heat-resistant glass can withstand heat of 1,200°C, sapphire glass can withstand heat of 2,000°C. Thermal conductivity is better than general heat-resistant glass.
• High transparency
  … The sapphire glass made from synthetic sapphire is colorless and transparent without any impurities.

Applications of sapphire glass

Sapphire glass is mainly used for the following applications.

• LED substrate
  … It is used for LED-related manufacturing because it can withstand heat of 2,000°C or more and has high transparency. It is also used as a substrate for blue and white LEDs (light emitting diodes).
• Equipment materials and windows for extreme environments
  … Sapphire glass, which has high strength, corrosion resistance, and heat resistance, is used as a window material for high-pressure tanks, semiconductor equipment, high-temperature equipment, chemical plants, and extreme environments.
• Inspection jig
  … Sapphire glass is extremely pure, colorless and transparent, and is used for the measuring stages of inspection jigs and inspection equipment because it has the property of transmitting light.
• Parts for research equipment and experimental equipment
  … It is used as equipment parts, laboratory instruments and experimental materials in university laboratories and public research institutes.
• Watch cover glass
  … It is used as a cover glass for watches because it is harder and less scratch-resistant than ordinary glass or plastic materials.

Please contact TDC for the polishing of sapphire, which is a difficult-to-process material.

TDC owns more than 100 polishing machines such as lapping machines and surface grinders.

In addition, the polishing technology we have accumulated so far enables us to handle polishing with any degree of precision.

Please feel free to contact TDC for the highly difficult sapphire polishing process that other companies have refused.

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