A method of cutting a glass sheet that has been thermally or chemically strengthened along a predetermined line, axis, or direction with high speed and with minimum damage on the cut edges. The strengthened glass sheet may be cut into at least two pieces, one of which having a predetermined shape or dimension. At least one damage line is formed within the strengthened glass sheet. The at least one damage line is formed outside the strengthened compressive stress surface layers and within the tensile stress layer of the strengthened glass sheet. The at least one damage line may be formed by laser treatment. A crack is initiated in the strengthened glass sheet and propagated along the at least one damage line to separate the strengthened glass sheet along the predetermined line, axis, or direction into at least two pieces.

Method of separating strengthened glass

A method for manufacturing a glass substrate (110) for use in magnetic disk manufacturing comprising the steps of a) forming a glass sheet (100); b) forming a protective sheet (102a, 102b) over one or both sides of the glass sheet; c) cutting the glass sheet into workpieces (104); d) cutting the workpieces into disk-shaped substrates (110); e) subjecting the edges of the substrates to an edge polishing process; and f) removing the protective layer. Of importance, by leaving the protective layer over the substrate, the substrate surface is protected from damage.

Method for manufacturing a magnetic disk comprising a glass substrate

An apparatus and method for physically separating non-metallic substrates by forming a microcrack in the substrate and controllingly propagating the microcrack. An initial mechanical or pulsed laser scribing device forms a microcrack in the substrate. A scribe beam is applied onto the substrate on a separation line. A coolant stream intersects with, or is adjacent to, the trailing edge of the scribe beam. The temperature differential between the heat affected zone of the substrate and the coolant stream propagates the microcrack. Two breaking beams on opposing sides of the separation line follow the coolant stream. The breaking beams create controlled tensile forces that extend the crack to the bottom surface of the substrate for full separation. The scribe and break beams and coolant stream are simultaneously moved relative to the substrate. A preheat beam preheats the heat affected area on the substrate. The beams are formed by an arrangement of lasers and mirrors and lenses. A movable mirror selectively diverts a beam to form either the preheat beam or one or more of the break and scribe beams. Spherical aberration is introduced in the break and scribe beams to flatten their energy distribution profiles and evenly apply the beam energy. A supplemental mechanical force, applied by vertically movable wheels or by restraining the substrate against a curved frame, creates a bending moment to facilitate the separation process.

Method and apparatus for separating non-metallic substrates utilizing a supplemental mechanical force applicator

A method for cutting a glass article from a strengthened glass substrate having a surface compression layer and a tensile layer includes forming an edge defect in the surface compression layer on a first edge of the strengthened glass substrate. The method further includes propagating a through vent through the surface compression and tensile layers at the edge defect. The through vent precedes a region of separation along a cut line between the glass article and the strengthened glass substrate.

Methods for laser cutting glass substrates

A method and apparatus for splitting non-metallic substrates includes a laser for generating a laser beam. An integrated cracking device receives the laser beam and directs the laser beam onto a non-metallic substrate to define the heat affected zone and quench the substrate at a quenching region contained within the heat affected zone. This integrated cracking device includes a housing and optics fitted within the housing for receiving and directing the laser beam onto the substrate. A quenching nozzle is mounted on the housing for quenching the substrate at a quenching region defined within the heat affected zone.

Method and apparatus for separating non-metallic materials

The method and apparatus for cutting through flat workpieces made of glass can cut through workpieces with greater thickness, e.g. glass panes with a thickness greater than 0.2 mm, than possible up to now with a comparable known method, without micro-fractures, glass fragments or splitter. In the method of the invention a heat radiation spot symmetric to the cutting line is produced on the workpiece. This heat radiation spot has edge portions with elevated radiation intensity and is moved along the cutting line and/or the workpiece and the heated section of the cutting line is subsequently cooled. A scanner motion produces the heat radiation spot so that edge portions of elevated radiation intensity coincide with a V- or U-shaped curve, which is open at the leading end of the heat radiation spot. The peak portion of the V- or U-shaped curve on the cutting line is at a temperature maximum that is under the melting point of the workpiece material. A controller of the scanning motion controls the scanner in circular cutting and freeform cutting so that a curved V- or U-shaped intensity distribution which fits the curved cutting path arises.

Method and apparatus for cutting through a flat workpiece made of brittle material, especially glass.

The method involves a relative motion of the workpiece material (1) and a symmetric heat radiation spot (3) along a separation line (2), with subsequent cooling of the heated separation line section. The heat radiation spot has a higher radiation intensity on its edge zone and a maximum temperature at its back end. The spot with higher heat radiation on a V or U shaped curve (4) has a maximum temperature which is below the melting point of the workpiece material at the vertex (16). The apparatus includes a heat radiation source, particularly a laser, and an optical system for producing a radiation spot with the required characteristics. It further includes means for producing a relative motion of the workpiece and the heat radiation spot, as well as means for subsequent cooling the radiated separation line.

Process and apparatus for splitting flat pieces of brittle material, particularly of glass

PROBLEM TO BE SOLVED: To provide a method for cutting a flat processed article, for example, a glass sheet thicker than 0.2 mm, without the occurrence of microcracks and the breaking or fissuring of glass and a device therefor. SOLUTION: This method consists in a) heating the cutting line 2 with a heat radiation spot 3 symmetrical with the cutting line, which heat radiation spot has end edge parts 18, 19 having the intensity of the relatively large radiation as compared with the intensity of the radiation thereof and has the max. point of the temp. at the rear end of the heat radiation spot and b) moving the heat radiation spot 3 along the cutting line 2 and/or the processed articles. The method includes c) a stage for cooling the part of the cutting line heated by heating of the stage a). The end edge parts of heat radiation spot coincide with a V-shaped or U-shaped curve 4 opened at the front end of the heat radiation spot in the moving direction of the heat radiation spot 3 and/or the processed article and the max. point of the temp. described above is locally arranged on the peak part 16 of the V-shaped or U-shaped curve 4 on the cutting line and is below the melting temp. of the processed article.

Ralf Steinfartz

Papers

Method and apparatus for cutting through a flat workpiece made of brittle material, especially glass.

Process and apparatus for splitting flat pieces of brittle material, particularly of glass

Method for cutting brittle material, more particularly flat processed articles made of glass and device therefor