A method of forming a plastic molding type secondary battery. A protective circuit board is electrically connected to a bare cell, both mounted in a mold. The mold is capable of receiving the protective circuit board connected to the bare cell and at least of a part of the bare cell, and has an insertable core corresponding to the surface of an external I/O terminal, which is axially movable so as to contact the terminal surface. Supporting pins are trans-axially dispersed in the mold so that a lateral part of the pin is in contact with the back surface of the protective circuit board disposed in a correct position. A resulting plastic molding type secondary battery has pinholes formed on a part made of the plastic molding in the direction parallel to the protective circuit board so as to come into contact with one surface of the protective circuit board.