| 摘要 |
PURPOSE: A laser machining apparatus is provided to prevent unintended boring of a bonding pad by stopping the projection of a laser beam when a laser machining hole reaches the bonding pad. CONSTITUTION: A laser machining apparatus comprises a chuck table holding a work piece, a laser beam projection unit, a reflection unit(9), a wavelength sensing unit(10), and a control unit. The laser beam projection unit comprises a laser beam generator(6) and a condenser(8) which condenses a laser beam provided by the laser beam generator and projects the laser beam to the work piece on the chuck table. The reflection unit is arranged on the optical axis of the condenser and reflects plasma light generated from the work piece while allowing passage of the laser beam. The wavelength sensing unit senses the wavelength of the plasma light reflected by the reflection unit. The control unit determines the material of the work piece based on the wavelength sensed by the wavelength sensing unit and controls the laser beam projection unit. |
