A build plate-clamping assembly may include a work station having a build plate-receiving surface and a lock-pin extending from the build plate-receiving surface of the work station. The lock-pin may include a hollow pin body, a piston disposed within the hollow pin body, with the piston axially movable from a retracted position to an actuated position, and a plurality of detents, with the plurality of detents radially extensible through respective ones of a plurality of detent-apertures in the hollow pin body responsive to the piston having been axially moved to the actuated position. A methods of working on workpieces may include lockingly engaging a build plate at a first work station, performing a first work-step, releasing the build plate from the first work station, lockingly engaging the build plate at a second work station, and performing a second work-step. An additive manufacturing system may include a vision system with a first build plate-receiving surface and an additive manufacturing machine with a second build plate-receiving surface.

A laser processing device includes a support unit, a laser light source, a reflecting spatial light modulator, a light collection optical system, an imaging optical system, a mirror, a first sensor configured to acquire displacement data on a laser light entry surface, and a second sensor configured to acquire displacement data on the laser light entry surface. An optical path of the laser light extending from the mirror to the light collection optical system is set along a first direction. An optical path of the laser light extending from the reflecting spatial light modulator to the mirror through the imaging optical system is set along a second direction. The first sensor is disposed on one side of the light collection optical system in a third direction.

A laser processing device includes a support unit, a laser light source, a reflecting spatial light modulator, a light collection optical system, an imaging optical system, a mirror, a first sensor configured to acquire displacement data on a laser light entry surface, and a second sensor configured to acquire displacement data on the laser light entry surface. An optical path of the laser light extending from the mirror to the light collection optical system is set along a first direction. An optical path of the laser light extending from the reflecting spatial light modulator to the mirror through the imaging optical system is set along a second direction. The first sensor is disposed on one side of the light collection optical system in a third direction.

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.

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 wafer processing method includes a modified layer forming step of applying a laser beam of a wavelength having transmitting property to a wafer with a focusing point of the laser beam positioned inside the wafer at positions corresponding to division lines, thereby to form modified layers, and a back side grinding step of holding the wafer on a chuck table of a grinding apparatus, grinding a back side of the wafer to thin the wafer, and dividing the wafer into individual device chips from cracks that are generated from the modified layers formed inside the wafer along the division lines to the division lines formed on a front side of the wafer. In the modified layer forming step, in a case where triangular chips each having a surface area smaller than the device chips are to be formed, the application of the laser beam is stopped in a region where the triangular chips are to be formed.

A laser calibration device includes a scanning surface, an optical detector for scanning a calibration substrate arranged on the scanning surface, and a processing unit. The optical detector is movable with respect to the scanning surface with not more than two, preferably not more than one, degree of freedom. The processing unit is configured for: generating pattern generation executable instructions to generate a calibration pattern on a calibration substrate by one or more laser processing devices of a laser processing apparatus; detecting a calibration pattern generated based on such pattern generation executable instructions; and based on a detected calibration pattern and on the corresponding pattern generation executable instructions, generating calibration executable instructions for calibrating the one or more laser processing devices of said laser processing apparatus.

A laser calibration device includes a scanning surface, an optical detector for scanning a calibration substrate arranged on the scanning surface, and a processing unit. The optical detector is movable with respect to the scanning surface with not more than two, preferably not more than one, degree of freedom. The processing unit is configured for: generating pattern generation executable instructions to generate a calibration pattern on a calibration substrate by one or more laser processing devices of a laser processing apparatus; detecting a calibration pattern generated based on such pattern generation executable instructions; and based on a detected calibration pattern and on the corresponding pattern generation executable instructions, generating calibration executable instructions for calibrating the one or more laser processing devices of said laser processing apparatus.

A method of detecting center coordinates of a spot welding mark includes: a linear laser light emitting step of emitting a plurality of linear laser light components with a linear irradiation trace on a spot welding mark by emitting laser light through continuous output oscillation; a waveform acquiring step of acquiring a waveform of an intensity of return light which is light generated from a processing point; an outer edge position coordinates deriving step of deriving position coordinates of three or more points on an outer edge of the spot welding mark from a peak position of the intensity of the waveform of the return light; and a center coordinates calculating step of calculating center coordinates of the spot welding mark from the position coordinates of the three or more points on the outer edge derived in the outer edge position coordinates deriving step.

A method of detecting center coordinates of a spot welding mark includes: a linear laser light emitting step of emitting a plurality of linear laser light components with a linear irradiation trace on a spot welding mark by emitting laser light through continuous output oscillation; a waveform acquiring step of acquiring a waveform of an intensity of return light which is light generated from a processing point; an outer edge position coordinates deriving step of deriving position coordinates of three or more points on an outer edge of the spot welding mark from a peak position of the intensity of the waveform of the return light; and a center coordinates calculating step of calculating center coordinates of the spot welding mark from the position coordinates of the three or more points on the outer edge derived in the outer edge position coordinates deriving step.