A wafer is produced from a compound single crystal ingot having an end surface. A separation plane is formed by setting the focal point of a laser beam inside the ingot at a predetermined depth from the end surface. The depth corresponds to the thickness of the wafer to be produced. The laser beam is applied to the end surface to form a modified layer parallel to the end surface and cracks extending from the modified layer, thus forming the separation plane. The ingot has first atoms having a larger atomic weight and second atoms having a smaller atomic weight, and the end surface of the ingot is set as a polar plane where the second atoms are arranged in forming the separation plane. After producing the wafer from the ingot, the first end surface is ground to be flattened.

Providing a solid body to be split into a number of layers of solid material, introducing or generating defects in the solid body in order to determine a first detachment plane (8) along which a first layer of solid material is separated from the solid body, providing a receiving layer for holding the layer of solid material on the solid body, applying heat to the receiving layer in order to generate, in particular mechanically, stresses in the solid body, due to the stresses a crack propagating in the solid body along the detachment plane, which crack separates the first layer of solid material from the solid body, then providing a second receiving layer for holding another layer of solid material on the solid body reduced by the first layer of solid material, introducing or generating defects in the solid body in order to determine a second detachment plane (9) along which a second layer of solid material is separated from the solid body, applying heat to the second receiving layer in order to generate, in particular mechanically, stresses in the solid body, due to the stresses a crack propagating in the solid body along the second detachment plane, which crack separates the second layer of solid material from the solid body.

With a method of cutting a tube glass (G1) according to the present invention, the tube glass (G1) is irradiated with laser light (L) having a focal point (F) adjusted to an inside of the tube glass (G1), to thereby form an inner crack region (C1) including one or more cracks in a portion of the tube glass (G1) in a circumferential direction of the tube glass (G1) through multiphoton absorption that occurs in an irradiation region of the laser light (L). Then, in the tube glass (G1), there is generated a stress that urges the one or more cracks in the inner crack region (C1) to propagate in the circumferential direction of the tube glass (G1) to cause the one or more cracks to propagate throughout an entire circumference of the tube glass (G1), to thereby cut the tube glass (G1).

The purpose of the present invention is to provide an easy-to-use and efficient method for cutting a concrete member, in particular, a method that is for cutting a reinforced concrete member, that makes it easy to increase cutting depth and cutting width, and that is low in cutting cost. To achieve the purpose, the present invention provides a method for cutting a concrete member through irradiation of the concrete member with laser, the method being characterized in that: the concrete member includes a steel material; concrete is melted by scanning laser thereon to form a cutting region; the steel material is heated by means of laser to a temperature that causes progression of self-burning of the steel material; and the melting of the concrete is expedited by heat generation from said self-burning.

The present invention relates to a method for separating solid-body slices (1) from a donor substrate (2). The method comprises the steps of: producing modifications (10) within the donor substrate (2) by means of laser beams (12), wherein a detachment region is predefined by the modifications (10), along which detachment region the solid-body layer (1) is separated from the donor substrate (2), and removing material from the donor substrate (2), starting from a surface (4) extending in the peripheral direction of the donor substrate (2), in the direction of the centre (Z) of the donor substrate (2), in particular in order to produce a peripheral indentation (6).

A heat chamfering apparatus. A support unit supports a glass panel. A heat chamfering unit heat-chamfers an edge of the glass panel by applying thermal shock thereto. The support unit includes a contact support portion supporting the glass panel while in contact with the glass panel and a base portion configured to support the contact support portion. The contact support portion is formed from a first material. The base portion is formed from a second material. The first material has a smaller change in temperature due to lower thermal conductivity and a smaller change in size at high temperature due to a smaller coefficient of thermal expansion while being more ductile due to lower hardness, compared to the second material. In a heat chamfering method, a glass panel is located on a support unit, and an edge of the glass panel is heat-chamfered by applying thermal shock thereto.

A method of fabricating a glass panel includes forming a non-chamfered glass panel by cutting a glass sheet. The non-chamfered glass panel is formed by cutting the glass sheet along a first sideline segment, cutting the glass sheet along a corner line segment set connected to the first sideline segment, and cutting the glass sheet along a second sideline segment connected to the corner line segment set. An extension of the first sideline segment and an extension of the second sideline segment intersect each other at a first interior angle narrower than 230?. The first sideline segment and the corner line segment set are connected at an interior angle wider than the first interior angle and 180? but narrower than 230?. The corner line segment set and the second sideline segment are connected at an interior angle wider than the first interior angle and 180? but narrower than 230?.

A heat chamfering apparatus includes a heated body configured to peel an edge of a glass panel by applying thermal shock to the glass panel while being in contact with the edge of the glass panel and a heater heating the heated body. The heated body includes a heated region and a contact region in a longitudinal direction thereof, the heated region being heated by the heater, and the contact region being configured to be in contact with the glass panel. The cross-sectional area of the contact region is smaller than the cross-sectional area of the contact region. A heat chamfering method includes peeling an edge of a glass panel by applying thermal shock to the edge of the glass panel by moving a heated body heated by a heater relatively with respect to the glass panel along and in contact with the edge of the glass panel.

Disclosed herein is a wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot. The wafer producing method includes a modified layer forming step of setting the focal point of a laser beam having a transmission wavelength to the ingot inside the ingot at a predetermined depth from the upper surface of the ingot, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot as relatively moving the focal point and the ingot to thereby form a modified layer parallel to the upper surface of the ingot and cracks extending from the modified layer. In the modified layer forming step, the focal point of the laser beam is relatively moved from a radially inside position inside the ingot toward the outer circumference of the ingot.

The present invention relates to a method for separating solid-body slices (1) from a donor substrate (2). The method comprises the steps of: producing modifications (10) within the donor substrate (2) by means of laser beams (12), wherein a detachment region is predefined by the modifications (10), along which detachment region the solid-body layer (1) is separated from the donor substrate (2), and removing material from the donor substrate (2), starting from a surface (4) extending in the peripheral direction of the donor substrate (2), in the direction of the center (Z) of the donor substrate (2), in particular in order to produce a peripheral indentation (6).