| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a machining method in removing resin in a continuous wide-ranging area at an efficient machining speed without leaving resin on the processed surface after the removal, in removing a specific part of the resin layer whose main composition is polyimide suitable for the insulating resin layer of a wiring board. SOLUTION: In the method of removing a part of an insulating resin layer consisting essentially of polyimide by irradiating the layer with a pulse-formed CO2 laser beam, the CO2 laser beam is designed to be a pulsed laser beam having an energy density of 5 J/cm2 or above on the machining face and the pulse peak output of 500 W or higher, and to contain a process of emitting a CO2 laser beam of two pulses or more intermittently, at intervals of 100μm second or less, at irradiation intervals of one beam diameter or less, and in the manner that the n-th (n is an integer of 1 or above) pulse irradiation area is unadjacent to the (n+1)th.</p> |
