A flexible circuit board is provided to prevent unsuccessful interconnection between the wirings of the flexible circuit board and the output terminals of a semiconductor chip, the flexible circuit board having a plurality of sections of wirings of different sizes, each section including a pattern of wirings of the same size. The flexible circuit board has predetermined patterns of wirings on an insulating material base, and the wirings are electrically connected to the output terminals of a semiconductor chip. A pattern of the wirings of the same size forms a first wiring section, while another pattern of the wirings of the same size form a second wiring section. The flexible circuit board is provided with a pattern transition region between the neighboring wiring sections with wirings of different sizes to avoid unsuccessful interconnection which would be otherwise caused by the difference in size between the wirings.
展开▼
