MULTI-LAYER PRINTED CIRCUIT BOARD, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a multi-layer printed circuit board resistant against bending stress by reducing damage of generation of crack in a flexible film at the position of root of rigid part 11 and flexible part 12. SOLUTION: The multi-layer printed circuit board is manufactured so as to have the rigid part wherein an outer layer substrate is laminated on the flexible film on which a cover-lay film is laminated, the flexible part consisting of the flexible film on which the outer layer substrate is not laminated, a reinforcing metal pattern closely contacted with the cover-lay film immediately below a border line between the rigid part and the flexible part, a projection of the reinforcing metal pattern which is provided with a root in the rigid part and is projected toward the side of the flexible part. The projection of the reinforcing metal pattern is projected toward the side of the flexible part in the width of 0μm to 150μm from the border line between the rigid part and the flexible part, while the thickness thereof becomes thinner as the projection goes away from the rigid part. COPYRIGHT: (C)2008,JPO&INPIT