| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method and a device for boring a printed circuit board, with which reliability in working and the quality of a bore can be improved and a desmear process is unnecessitated by leaving no remaining film on the bottom of the bore. SOLUTION: In the working method for the printed circuit board, the first layer of a surface is a conductor layer and the conductor layer and an insulating layer are alternately laminated. The conductor layer of the first layer is worked while making the energy density of the laser light of a first wavelength with high absorbent ratio at the conductor layer and the insulating layer into a level higher than the decomposition threshold of the conductor layer and the insulating layer. The insulating layer of the second layer is worked while making the energy density of the laser light of a second wavelength with low absorbent ratio at the conductor layer, but with high absorbent ratio at the insulating layer, into a level lower than the decomposition threshold of the conductor layer and higher than the decomposition threshold of the insulating layer. The insulating layer of the second layer is finished while making the energy density of the laser light of a third wavelength with high absorbent ratio of at the insulating layer, into energy density higher than the decomposition threshold of the insulating layer and lower than the decomposition threshold of the conductor layer so that the conductor layer of the third layer can be exposed.</p> |
