Patent ID: 7605343
Filing Date: 2009-10-20
Classification: B23K,H05K

Abstract:
1. A method for increasing laser via drilling throughput by minimizing a total number of pulses used to drill a via having desirable operational characteristics, wherein the total number N of pulses includes a bulk number N 0 of bulk removal pulses employed to remove bulk material to form the via with a laser removal-bulk material interaction and a bottom surface cleaning number δN of bottom surface cleaning pulses employed to clean a bottom surface of the via with a laser cleaning-material interaction, comprising: generating, from a laser, laser output having a wavelength shorter than 400 nanometers, a fluence F, and at least one laser pulse having a pulsewidth τ, shorter than 1000 picoseconds, for cleaning the bottom surface of the via, where δN has a relationship to F/τ directing the laser output from the laser to a target position to remove a major portion of the bulk material and clean the bottom surface of a via, such that laser pulses of the laser output for removing the major portion of the bulk material and for cleaning the bottom surface of the via have a wavelength shorter than 400 nanometers and a pulsewidth shorter than 1000 picoseconds.