The company produces sapphire watch blanks of 2 geometric forms: circular and square. Blanks can be prepared according to several crystallographic orientations: (1120), arbitrary, (0001), and also with the orientation of one side of the rectangular blank along (0001).
2. Wafers for microelectronics
Sapphire wafers of orientation (1012) are used for both integrated circuits (IC) and strain gauge sensors. Wafer diameters can be 3", 4" or 6".
3. Sapphire tubes
The use of monocrystalline sapphire as the material for various tubes is primarily due to its physico-mechanical properties:
highly chemically inert — as protection covers when working in aggressive environ-ments;
high mechanical strength — parts that can withstand high pressure;
high melting temperature — parts that work at high temperatures;
high transmittance — used for monitoring and measuring purposes since it allows the passage of electromagnetic radiation in the range between 200 nm to 5 μm.
Depending on their size, tubes can be made either by directly growing them with the help of a former in the Stepanov method (EFG) or from regular monocrystalline sapphire grown by the Kyropoulos method. Whilst the Stepanov method produces pipes of small diameters up to 40 mm, massive pipes with diameters of up to 250 mm can be produced from crystals obtained by the Kyropoulos method. The minimum internal diameter of pipes grown by the Stepanov method is of the order of 0.8 mm.
4. Optical elements and observation windows
Sapphires high melting point (≈ 2050 °С) and wide transmittance spectrum (from 0.2 to 5 μm) make it an indispensable material for the manufacturing of optical elements and viewing windows.In material replacement cases (for e.g. from quartz to sapphire) sapphire can increase the longevity of materials due to its high resistance to abrasion.
ROKOR produces grinded and/or polished optical elements and observation windows. Dimensions of parts can be up to 280 mm in diameter for circular form and edge length of up to 280 mm for rectangular form. Orientation of parts for optical elements can be c, a, r or m. When placing an order, maximum sizes and the quality category of parts need to be outlined separately.
5. Cylinders (ingots) and wafers for LED
The LED industry is a major market for sapphire wafers, accounting for millions of wafers ∅4. ROKOR supplies small batches of wafers with orientation (0001), diameters 2", 3", 4", 6" with deviations from standard requirements and sizes; mostly to research institutes and small companies developing new types of LEDs on the basis of sapphire wafers. Additionally, small batches of cylinders for LED (diameters 2", 3", 4", 6") can be prepared according to agreed requirements.
