| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for inexpensively and stably manufacturing a multilayer flexible printed wiring board having a small-diameter step via structure. <P>SOLUTION: The multilayer flexible printed wiring board comprises: a flexible insulating base material 11; an insulating base material 21 laminated on a rear surface of the insulating base material 11 via an adhesive layer 24; a step via hole 25 having an upper hole 26 that penetrates the insulating base material 11 and a lower hole 27 that penetrates the adhesive layer 24 and the flexible insulating base material 21 and where a land 31 is exposed to a bottom surface; a land 30 formed on the surface of the insulating base material 11; a land 17b formed on the rear surface of the insulating base material 11; and a step via 29 having an interlayer conductive path 29a that connects the land 30 and the land 17b and an interlayer conductive path 29b that connects the land 31 and the land 17b. The difference in diameters between the upper hole 26 and the lower hole 27 in a roll direction of flexible base materials used as a starting material is bigger than the difference in diameters between the upper hole 26 and the lower hole 27 in a perpendicular direction to the roll direction. <P>COPYRIGHT: (C)2012,JPO&INPIT |
