A saw wire to cut hard and brittle materials is disclosed that comprises a steel wire that is provided with bends with segments in between. The average degree of bending of the bends is between 0.5% and 5%. Such a saw wire has a higher breaking load compared to saw wires having a conventional, higher average degree of bending. A method to measure the curvature is described as well as a process to make the inventive saw wire. The invention is applicable to any shaped saw wire for example a single crimped saw wire, a saw wire with at least two crimps in different planes, a saw wire with crimps rotating in a plane.

One example describes a method of manufacturing Czochralski (CZ) silicon wafers. The method includes slicing an n-type CZ silicon ingot to form a plurality of CZ silicon wafers, determining a boron concentration of each CZ silicon wafer, dividing the CZ silicon wafers into sub-groups based on the boron concentration, wherein an average value of the boron concentration differs among the sub-groups, and labeling each sub-group of CZ silicon wafers with a different label which is indicative of the boron concentration.

One example describes a method of manufacturing Czochralski (CZ) silicon wafers. The method includes slicing an n-type CZ silicon ingot to form a plurality of CZ silicon wafers, determining a boron concentration of each CZ silicon wafer, dividing the CZ silicon wafers into sub-groups based on the boron concentration, wherein an average value of the boron concentration differs among the sub-groups, and labeling each sub-group of CZ silicon wafers with a different label which is indicative of the boron concentration.

Examples of gemstone verification are described herein. In one example, for processing a gemstone, pre-stored marking coordinates associated with a gemstone ID are obtained, the pre-stored marking coordinates generated during planning phase of the processing. Further, real-time marking coordinates for the gemstone to be processed are also obtained. An identity of the gemstone is verified based on a comparison of the pre-stored marking coordinates with the real-time marking coordinates. Further, information, including cutting parameters, associated with the gemstone ID of the gemstone is retrieved in response to a valid verification of the identity of the gemstone, for processing the gemstone.

Examples of gemstone verification are described herein. In one example, for processing a gemstone, pre-stored marking coordinates associated with a gemstone ID are obtained, the pre-stored marking coordinates generated during planning phase of the processing. Further, real-time marking coordinates for the gemstone to be processed are also obtained. An identity of the gemstone is verified based on a comparison of the pre-stored marking coordinates with the real-time marking coordinates. Further, information, including cutting parameters, associated with the gemstone ID of the gemstone is retrieved in response to a valid verification of the identity of the gemstone, for processing the gemstone.

Systems and methods are described for controlled crack propagation in a material using ultrasonic waves. A first stress in applied to the material such that the first stress is below a critical point of the material and is insufficient to initiate cracking of the material. A controlled ultrasound wave is then applied to the material causing the total stress applied at a crack tip in the material to exceed the critical point. In some implementations, the controlled cracking is used for wafering of a material.

A substantial reduction in scrap produced by an interrupted process for the sawing of a workpiece into a multiplicity of wafers with a wire saw caused by wire breakage, is made possible by detecting the exact or approximate position of the wire break, repairing or replacing the sawing wire, and rethreading the sawing wire web into the saw kerfs, while excluding the kerf in which breakage occurred.

The present subject matter discloses a longitudinal silicon ingot slicing apparatus for lateral slicing of cylindrical ingot to maximize resulting chips yield as compared to the conventional transverse slicing of ingot. The resulting rectangular wafers made from lateral slicing of ingot maximizes yield as by the lateral slicing of ingot, overall chips per wafer ratio gets increased as compared to transversal cutting while the said apparatus and method decreases waste due to conflict between chip and wafer geometry. The novel apparatus of longitudinal slicing of cylindrical ingot is comprising of a wire wounded around a wire reels and a plurality of grooved rollers to form a wire raw to slice the cylindrical silicon ingot. A motors are connected with the wire reels and with at least one grooved roller to slide the wire row back and forth to cut the cylindrical ingot. A work feed table is also configured along with the JIG fixture that holds the cylindrical ingot as well as align the wire raw during slicing.

A saw wire includes a metal wire containing rhenium-tungsten alloy. A rhenium content of the metal wire is at least 0.1 wt % and at most 10 wt % with respect to a total weight of rhenium and tungsten, an elastic modulus of the metal wire is at least 350 GPa and at most 450 GPa, a tensile strength of the metal wire is at least 3500 MPa, and a diameter of the metal wire is at most 60 m.

In accordance with a method of manufacturing CZ silicon wafers, a parameter of at least two of the CZ silicon wafers is measured. A group of the CZ silicon wafers falling within a tolerance of a target specification is determined. The group of the CZ silicon wafers is divided into sub-groups taking into account the measured parameter. An average value of the parameter of the CZ silicon wafers of each sub-group differs among the sub-groups, and a tolerance of the parameter of the CZ silicon wafers of each sub-group is smaller than a tolerance of the parameter of the target specification. A labeling configured to distinguish between the CZ silicon wafers of different sub-groups is prepared. The CZ silicon wafers falling within the tolerance of the target specification are packaged.