METHOD AND DEVICE FOR MEASURING THE DEPTH OF THE VAPOR CAPILLARY DURING A MACHINING PROCESS WITH A HIGH ENERGY BEAM

In a method for measuring the depth of the vapour cavity (88) during an industrial machining process with a high-energy beam (19), an optical measuring beam (70a) is directed towards the base of a vapour cavity (88). An optical coherence tomograph (40) generates interference factors or other raw measurement data from reflections of the measurement beam (70a). An evaluation device (114) generates interference-suppressed measurement data, wherein raw measurement data, that is generated at different times, is processed together in the course of a mathematical operation. This operation can be, in particular, a subtraction or a division. In this way, slowly changing interference factors can be eliminated. An end value for the distance (a1) to the base of the vapour cavity (88) is calculated from the interference-suppressed measurement data using a filter, e.g. a quantile filter. As a result, the depth of the vapour cavity (88) can be determined, in the knowledge of the distance at a part of ...

METHOD FOR MEASURING THE DEPTH OF PENETRATION OF A LASER BEAM INTO A WORKPIECE, AND LASER MACHINING DEVICE

The invention relates to a method for measuring the depth of penetration of a laser beam (19) into a workpiece (24, 26), wherein the laser beam is focused in a focal spot (22) by means of a focusing optical unit (14) arranged in a machining head. The focal spot produces a vapor capillary (88) in the workpiece. An optical coherence tomograph (40) produces a first measurement beam (70a) and a second measurement beam (70b). The first measurement beam (70a) is directed at a first measurement point (MPa) at the base of the vapor capillary (88) in order to thereby measure a first distance (a1) between a reference point and the first measurement point (MPa). At the same time, the second measurement beam (70b) is directed at a second measurement point (MPb) on a surface (92) of the workpiece (24) which faces the machining head (14) and which is outside of the vapor capillary (88) in order to thereby measure a second distance (a2) between the reference point and the second measurement point (MPb ...

MACHINING HEAD FOR A LASER MACHINING DEVICE COMPRISING A PATH-LENGTH MODULATOR IN THE REFERENCE ARM; METHOD FOR LASER MACHINING OF A WORKPIECE, COMPRISING CORRESPONDING STEPS

The invention relates to a machining head for a laser machining device, which is equipped for machining a workpiece (24) using laser radiation (30). The laser machining head comprises an adjustable focusing optical unit (34), which focuses the laser radiation (30) in a focal spot (22). The distance between the focal spot (22) and a machining head can be modified by modifying the focal length of the focusing optical unit (34). A scanning apparatus (44) deflects the laser radiation (30) in different directions. An optical coherence tomography device (48) measures a distance between the treatment head and the workpiece (24). Here, measuring light (52), which was generated by a measuring light source (50) and reflected by the workpiece (24), interferes in the coherence tomography device (48) with measuring light, which travelled an optical path length in a reference arm (60). A path-length modulator (74) is disposed in the reference arm (60) and it updates the optical path length in the reference ...

DEVICE FOR MEASURING THE DEPTH OF A WELD SEAM IN REAL TIME

The invention relates to a device for measuring the depth of a weld seam in real time in the case of the welding or joining of a workpiece by means of radiation, comprising: a measurement light source, the light of which is coupled into a reference arm (18) and into a measurement arm (19) by a beam splitter (17); a collimator module (21), which has at least one collimating lens (29) for collimating a measurement light beam (23), which is fed to the collimator module (21) by means of an optical waveguide (20) in the measurement arm (19), and for imaging the measurement light beam (23) reflected back by a workpiece to be processed onto an outlet/inlet surface (26) of the optical waveguide (20); an incoupling element (24) for coupling the measurement light beam (23) into the beam path of a processing beam (10); a focusing lens (25) for jointly focusing the measurement light beam (23) and the processing beam (10) onto the workpiece and for collimating the measurement light beam (23) reflected ...

A DEVICE AND A METHOD FOR DISTANCE MEASUREMENT FOR A LASER PROCESSING SYSTEM, AND A LASER PROCESSING SYSTEM

The present disclosure relates to a device (500) for distance measurement for a laser processing system (100). The device (500) comprises a light source (510), which is designed to produce a primary beam for directing at a workpiece (1), at least one detection device (520), which is designed to detect a secondary beam reflected by the workpiece (1), at least one optical amplifier (530), which is designed to amplify the primary beam and/or the secondary beam, and an evaluation unit, which is designed to evaluate interference of spectral components in the frequency range.

DEVICE FOR MEASURING THE DEPTH OF A WELD SEAM IN REAL TIME

The invention relates to a device for measuring the depth of a weld seam in real time in the case of the welding or joining of a workpiece by means of radiation, comprising: a measurement light source, the light of which is coupled into a reference arm (18) and into a measurement arm (19) by a beam splitter (17); a collimator module (21), which has at least one collimating lens (29) for collimating a measurement light beam (23), which is fed to the collimator module (21) by means of an optical waveguide (20) in the measurement arm (19), and for imaging the measurement light beam (23) reflected back by a workpiece to be processed onto an outlet/inlet surface (26) of the optical waveguide (20); an incoupling element (24) for coupling the measurement light beam (23) into the beam path of a processing beam (10); a focusing lens (25) for jointly focusing the measurement light beam (23) and the processing beam (10) onto the workpiece and for collimating the measurement light beam (23) reflected ...

Apparatus and method for determining a depth of a region having a high aspect ratio that protrudes into a surface of a semiconductor wafer

Apparatus for determining a depth of a region having a high aspect ratio that protrudes into a surface of a semiconductor wafer is provided. The apparatus comprises a multi-wavelength light source, a semiconductor wafer holder for holding a semiconductor wafer, a head for directing the light source onto the semiconductor wafer, a spectrometer for collecting light comprising multiple wavelengths reflected from the semiconductor wafer and analysis means for determining a depth of the region from an interference pattern of light reflected from the semiconductor wafer by performing Fourier domain optical coherence tomography.

Apparatus for thinning a silicon wafer and method for monitoring a thickness of a silicon wafer

Device for measuring the depth of a weld seam in real time

A device for measuring the depth of a weld seam in real time during the welding or joining of a workpiece by means of radiation, including: its measuring light source, the light of which is coupled by a beam splitter into a reference arm and a measuring arm; a collimator module having at least one collimation lens for collimating a measuring light beam, which is fed to the collimator module via an optical waveguide in the measuring arm, and for imaging the measuring light beam, which is reflected from a workpiece to be processed, on an exit/entry surface of the optical waveguide; a coupling element for coupling the measuring light beam into the beam path of a processing beam; a focusing lens for the joint focusing of the measuring light beam and the processing beam on the workpiece and for the collimating of the reflected measuring light beam; and an analysis unit for determining the depth of a weld seam, into which the measuring light reflected from the workpiece is guided with the superimposed ...