Patent ID: 7531767
Filing Date: 2009-05-12
Classification: B23K,C23F,H01L,H05K,Y02B

Abstract:
1. A method for perforating a printed circuit board having conductor layers and insulating layers laminated alternately, the method comprising the steps of: irradiating each conductor layer with a pulsed laser beam whose energy density is set at a value enough to process the conductor layer, while monitoring emission from a processed portion; obtaining the number of pulses of irradiation required for processing a window in the conductor layer; and processing a window in another place of the conductor layer by the obtained number of pulses of irradiation; wherein the number of pulses of irradiation required for processing a window in each conductor layer is obtained in each of a plurality of different places, and a maximum value of the obtained numbers of pulses of irradiation is set as the number of pulses of irradiation for the conductor layer.