MANUFACTURE OF PRINTED CIRCUIT BOARD

PURPOSE:To eliminate occurrence of a malfunction due to presence of a foreign matter at the time of exposure when a circuit is formed of a positive type photoresist. CONSTITUTION:The surface of a metal layer 2 is coated with a positive type photoresist 3 by electrodepositing, a photomask 4 is superposed on the photoresist 3, exposed, developed, the exposed part of the photoresist 3 is removed, and etched to form a circuit 6. In this case, the etching is overetched by using the photomask 4 formed by providing a mask line 5 in a width larger than that of the designed circuit 6. Even if the photoresist 3 remains at an undissolved part upon developing due to presence of a foreign matter in the case of exposure, the layer 2 of the lower side of the remaining part is dissolved to be removed by overetching.