In a carbon dioxide laser machining method of a multilayer material of applying
carbon dioxide laser light to a machined part of a multilayer material having an
insulation layer and a first conductor layer and a second conductor layer deposited
with the insulation layer between and removing the first conductor layer and the
insulation layer of the machined part to form a blind hole or a groove arriving
at the second conductor layer, the laser light is applied to the machined part
like pulses at an energy density of 25 J/cm2 or more for beam ON time
in the range of 1 s to 10 s.
