Laser machining apparatus

Abstract

The invention provides a laser processing apparatus capable of properly measuring the height of a processed object and performing laser processing on an expected position. A laser beam irradiation unit of the laser processing apparatus includes: a spectroscope disposed in a first optical path connecting a laser oscillator and a condenser; a broadband light source disposed in a second optical path branched by the spectroscope; a beam splitter disposed between the broadband light source and the beam splitter, the beam splitter branching off a third optical path from the second optical path; a Z-position detection unit that is disposed in a third optical path branched by the spectroscope and detects the position of the workpiece in the Z-axis direction on the basis of the intensity of light corresponding to the wavelength of return light that is reflected by the workpiece held by the chuck table and in which the light from the broadband light source is focused by the condenser; and a condenser moving mechanism that moves the condenser in the Z-axis direction in accordance with the Z-position.

Description

technical field [0001] The present invention relates to a laser processing device for processing a workpiece held by a chuck table by irradiating laser beams. Background technique [0002] The wafer is divided by a plurality of intersecting dividing lines, and multiple devices such as IC and LSI are formed on the front surface. The wafer is divided into individual device chips by a laser processing device, and the divided device chips are used in mobile phones, personal computers, etc. Electronic equipment. [0003] The laser processing device has: a chuck table that holds the workpiece; a laser beam irradiation unit that irradiates the workpiece held by the chuck table with laser light to perform processing; an X-axis feed mechanism that The chuck table and the laser light irradiation unit are indexed in the X-axis direction; the Y-axis feed mechanism, the chuck table and the laser light irradiation unit are arranged on the Y-axis perpendicular to the X-axis direction. di...

AI Technical Summary

Problems solved by technology

However, in the case of measuring the height of the wafer using this spectral interference waveform, there is a problem that the spectral interference waveform generated by the laminate on the upper surface of the wafer becomes noise and reduces the measurement accuracy.

In addition, measurement using spectroscopic interference waveforms requires irradiation of light over a wide measurement area, and there is also a problem that it is difficult to perform high-precision measurement with precise positioning in a narrow area.

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