| 摘要 |
PURPOSE:To increase a life of a drill in a step of drilling a through hole of a printed circuit board, to suppress a power source impedance to a low value, and to effectively dissipate heat at the time of supplying current to printed circuit. CONSTITUTION:Holes 7 are previously opened at through hole opening positions of a metal plate (copper plate) 6 for forming a power source layer and a ground layer of a printed circuit board 1A, the plate 6 is laminated together with boards 2a, 3a, 3b in a laminating step, and then through holes are opened. |
