摘要 |
After a isolation trench is formed in a conductive foil 70, insulating resin 50 is coated on the conducting foil 70 serving as a supporting board. The conductive foil 70 is turned upside down. Using the insulating resin 50 as another supporting board, the conductive foil is ground so that it is separated into the conductive passages. Thus, the mounting board can be constructed and manufactured using necessary and minimum material. The mounting board which can prevent the conductive passages from coming off can be realized by embedding the conductive passages 51 in the insulating resin to curve the side wall of each conductive passage 51 and/or make a visor coated on the conductive passage. <IMAGE> |