A system and a method for measuring the focus position of high-power laser are disclosed. The system includes a micro-controller, a stepping motor driver, an electric lifting platform, an electric rotation platform, a metal target, a displacement sensor, a photoelectric sensor and an ADC module. The system uses a laser to irradiate the metal target, which is moved upward and downward, to obtain the best ablation point through the ultraviolet radiation emitted on it.

A method for producing a wafer from a hexagonal single crystal ingot includes: planarizing an upper surface of the hexagonal single crystal ingot; applying a laser beam of such a wavelength as to be transmitted through the ingot, with a focal point positioned in an inside of a region not to be formed with devices of a wafer to be produced from the upper surface of the ingot which has been planarized, to form a production history; and applying a laser beam of such a wavelength as to be transmitted through the hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of the wafer to be produced from the upper surface of the hexagonal single crystal ingot which has been planarized, to form an exfoliation layer.

Methods, machines, and computer-readable mediums for determining distance correction values of a desired distance between a laser processing nozzle on a laser processing head and a workpiece during laser processing of the workpiece are provided. In some implementations, the workpiece is scanned along a desired path of a surface of the workpiece separately by the laser processing nozzle and a measurement head arranged in place of the laser processing nozzle on the laser processing head, with a capacitively measured distance identical to the desired distance. The measurement head has a lower lateral sensitivity of a capacitance measurement than the laser processing nozzle. Respective scanned movement paths of the laser processing nozzle and the measurement head are determined. The distance correction values for the desired distance of the laser processing nozzle are then determined from the scanned movement paths determined with the laser processing nozzle and the measurement head.

An optical processing apparatus includes a light source, a condensing optical system, and a shaping optical system. The light source emits light. The condensing optical system condenses the light emitted from the light source onto a processing target position on a surface of an object to be processed. The shaping optical system shapes a spot shape of the condensed light, such that a ratio of a major axis diameter of the spot shape to a minor axis diameter of the spot shape, in a cross section orthogonal to an optical axis of the condensed light on the object to be processed, is a minimum at or adjacent to a focal position of the shaping optical system. A method for optically processing an object is also provided.

Disclosed herein is a laser processing apparatus for forming a separation layer inside an ingot by applying a laser beam to an end surface of the ingot in the condition where the focal point of the laser beam is set inside the ingot, the laser beam having a transmission wavelength to the ingot. The laser processing apparatus includes a holding unit for holding the ingot, a moving unit for moving the holding unit in a direction parallel to the end surface of the ingot held by the holding unit, a laser beam applying unit for applying the laser beam to the ingot held by the holding unit, an imaging unit for detecting the position of the ingot in the direction parallel to the end surface of the ingot, and a height detecting unit for detecting the height of the end surface of the ingot held by the holding unit.

A workpiece-separating device includes: a holding member that detachably holds a workpiece among a layered body in which the workpiece that includes a circuit board and a supporting body that allows laser beams to pass therethrough are layered with each other via a separating layer that peelably alters with absorption of the laser beams; a laser irradiation part that performs irradiation of Gaussian beams pulse-oscillated as the laser beams toward the separating layer through the supporting body of the layered body held by the holding member; and a controlling part that controls an operation of the laser irradiation part, wherein the controlling part controls a distance between centers of the adjacent Gaussian beams of the laser beams pulse-oscillated from the laser irradiation part to be less than three times of a standard deviation when a relationship between a beam diameter and irradiation intensity is assumed as a normal distribution.

In a laser processing apparatus, a height of a focusing lens in a processing unit can be changed according to a change in height of an upper surface of a wafer, thereby changing a vertical position of a focal point of a laser beam inside the wafer. Accordingly, the laser beam can be applied to the wafer as feeding the wafer in a condition where the focal point is set at a vertical position spaced a fixed distance from the lower surface of the wafer. As a result, a modified layer can be formed inside the wafer at a uniform height from the lower surface of the wafer.

A laser processing method of performing laser processing on a transparent material that is transparent to ultraviolet light includes: A. a positioning step of performing positioning so that a transfer position of a transfer image is set at a position inside the transparent material at a predetermined depth Zsf from a surface of the transparent material in an optical axis direction; B. an irradiation condition acquisition step; C. a determination step of determining whether a maximum fluence of a pulse laser beam at the surface of the transparent material is within a predetermined range based on irradiation conditions; and D. a control step of allowing irradiation with the pulse laser beam when the maximum fluence is determined to be in the predetermined range.

This disclosure describes laser machining head gas nozzles that have an exit opening for passage of a laser beam onto a workpiece; an annular gap surrounding the exit opening; and a sleeve disposed and guided displaceably within the annular gap for axial displacement between a rearward and a forward position. The sleeve projects beyond the exit opening at least in the forward position, and the sleeve is tiltably mounted in the annular gap.

A method for producing a wafer from a hexagonal single crystal ingot includes: planarizing an upper surface of the hexagonal single crystal ingot; applying a laser beam of such a wavelength as to be transmitted through the ingot, with a focal point positioned in an inside of a region not to be formed with devices of a wafer to be produced from the upper surface of the ingot which has been planarized, to form a production history; and applying a laser beam of such a wavelength as to be transmitted through the hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of the wafer to be produced from the upper surface of the hexagonal single crystal ingot which has been planarized, to form an exfoliation layer.