Laser processing apparatus

A laser processing apparatus comprising:

• a chuck table for holding a workpiece thereon;
• a laser beam applying unit for applying a laser beam to the workpiece held on the chuck table;
• an image capturing sensor for producing a captured image of the workpiece that includes a captured image of light emitted from the workpiece when the laser beam is applied to the workpiece by the laser beam applying unit;
• and
• a control unit, wherein
• the laser beam applying unit includes
• a laser oscillator for emitting a laser beam, and
• a condensing lens for converging the laser beam emitted from the laser oscillator onto the workpiece, and
• the control unit includes a determining section for determining a state of the laser beam applied to the workpiece, on a basis of a shape of the captured image of the light that is included in the captured image of the workpiece, wherein
• the laser beam applying unit further includes a dichroic mirror for transmitting therethrough the laser beam emitted from the laser oscillator to the condensing lens and reflecting wavelengths other than a wavelength of the laser beam, and
• the captured image of the light is produced by the image capturing sensor when the laser beam emitted from the laser oscillator is propagated via the condensing lens and the dichroic mirror and applied to the workpiece by the laser beam applying unit, causing the workpiece to emit light that is transmitted through the condensing lens and reflected by the dichroic mirror to the image capturing sensor.

A laser processing apparatus comprising:

• a chuck table for holding a workpiece thereon;
• a laser beam applying unit for applying a laser beam to the workpiece held on the chuck table;
• an image capturing sensor for producing a captured image of the workpiece that includes a captured image of light emitted from the workpiece when the laser beam is applied to the workpiece by the laser beam applying unit;
• and
• a control unit, wherein
• the laser beam applying unit includes:
• a laser oscillator for emitting a laser beam, and
• a condensing lens for converging the laser beam emitted from the laser oscillator onto the workpiece, and
• the control unit includes a determining section for determining a state of the laser beam applied to the workpiece, on a basis of a shape of the captured image of the light that is included in the captured image of the workpiece,
• wherein the control unit further includes:
• a storage section for storing a reference image produced by the image capturing sensor through capturing of light emitted from the workpiece when the laser beam is applied under a predetermined condition to the workpiece by the laser beam applying unit, and
• a comparing section for comparing the captured image of the light with the reference image stored in the storage section, and
• the determining section determines a state of the laser beam on a basis of a result of the comparison between the captured image of the light and the reference image from the comparing section,
• wherein the storage section stores a plurality of reference images produced by the image capturing sensor through capturing of light emitted from the workpiece when the laser beam is applied under predetermined conditions to the workpiece by the laser beam applying unit, each of the plurality of reference images being associated with a different output power levels of the laser beam and
• wherein the comparing section is configured to compare the captured image of the light with the reference images stored in the storage section, and
• wherein the determining section determines a state of the laser beam on a basis of a result of the comparison between the captured image of the light and the reference images from the comparing section,
• wherein the size of the captured image and the reference images are determined by the respective output power levels of the laser beam.