| 摘要 |
A via hole machining method for forming via holes, reaching bonding pads, in a wafer having a plurality of devices which are formed on a face side of a substrate and are provided with the bonding pads, by irradiation with a pulsed laser beam from a back side of the substrate, wherein the energy density per pulse of the pulsed laser beam is set at such a value that ablation of the substrate will occur but ablation of the bonding pad will not occur, and the time interval of pulses of the pulsed laser beam is set at a value of not less than 150 microseconds.
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