DRILLING METHOD USING ULTRAVIOLET LASER

摘要

PROBLEM TO BE SOLVED: To provide a drilling method in which copper foil is hard to peel when drilling a copper foil and a resin layer. SOLUTION: A resin layer 32 and a copper foil layer 33 formed on the surface is irradiated with the ultraviolet rays pulsed laser beam that a peak of a pulse less than 10 kW and a pulse length no less than 100 ns to drill a hole.