| 摘要 |
PROBLEM TO BE SOLVED: To improve the junction characteristic of a through hole by executing a metal oxidation processing on the copper surface of a multilayer board, directly irradiating the surface with carbon dioxide laser energy, forming the through hole, removing the bur of copper foil in an inner layer and executing copper plating. SOLUTION: A backup sheet where copper oxide processing (e) is executed on the surface of the copper foil (a) of a four layer board, water-soluble polyester resin (f) is bonded to one face of aluminium (g) as a coat at a rear face is generated. The resin face is arranged to turn to the side of copper foil (a), carbon dioxide gas laser energy is irradiated and a through hole is formed. It is put in a plasma device and is processed. It is wet-processed in an ultrasonic wave in potassium permanganate solution, super alkaline water solution is sprayed at high speed and copper bur at inner/outer layers is dissolved and removed. Thus, the junction property of the through hole can be improved. |
