FLEXIBLE PRINTED WIRING BOARD

摘要

A flexible wiring board (10) is provided with component mounting parts (60A, 60B) whereupon circuit elements are mounted, and a bending part (70) to be bent in a bending axis direction, and an internal layer conductor layer (34U') is formed on an internal layer. In the component mounting parts (60A, 60B), component mounting part conductor layers (36U', 33L) are formed on the both planes of external layers (17U, 13), respectively. On the bending part (70), the bending part conductor layer (36U') is formed only on a plane to be on the external side when bent, out of the both planes of the external layers. As a result, crack resistance is improved by reducing the number of layers of the bending parts (70) to be less than the number of layers of the component mounting parts (60A, 60B), and a line impedance of the signal conductor pattern (36U') provided on the bending part (70) can be stabilized.