> Because the metallic conductor is essentially a mirror at the wavelength of the laser, the process is effectively “self terminating”, that is the laser vaporises all of the insulating material down to the conductor and then stops, so no process control is required to prevent damage to the conductor.
EDIT - found the answer:
> Because the metallic conductor is essentially a mirror at the wavelength of the laser, the process is effectively “self terminating”, that is the laser vaporises all of the insulating material down to the conductor and then stops, so no process control is required to prevent damage to the conductor.