| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a plating step or a pin and to improve the flexibility for continuity design than heretofore, concerning continuity between wiring layers of a printed wiring board provided with an insulating substrate and a plurality of wiring layers. SOLUTION: A through-hole 4 is made through an insulating substrate 2 and a wiring layer 3, a gold wire is inserted to the outside of the wiring layer 3 on the other side from the outside of the wiring layer 3 on one side, and then both ends of the gold wire 5 are pressure-welded to the optional wiring layers, respectively. One end of the gold wire 5 is projected from the through-hole 4 and is treated by sparking of an electric discharge electrode. Furthermore, the end thereof is made spherical and is bonded to the wiring layer 3 for the formation of continuity. COPYRIGHT: (C)2007,JPO&INPIT |
