Solder ball attracting mask and its manufacturing method

A method of manufacturing a solder ball attracting mask which is formed, at its predetermined positions, with a plurality of through-holes for attracting solder balls thereto, respectively, comprising the steps of:

• forming on an electrically conductive substrate a resist pattern having a plurality of resist portions corresponding to suction holes of the through-holes, respectively;
• electroforming on the electrically conductive substrate a first metal layer to a height identical with that of the resist portions;
• electroforming on the first metal layer a second metal layer overhanging the resist portions such that the second metal layer forms a funnel-shaped attraction area of each of the through-holes, wherein the funnel-shaped attraction area has a convexly curved tapered surface;
• and
• separating from the electrically conductive substrate the first and second metal layers held in close contact with each other integrally and removing the resist pattern from the first and second metal layers.