Method for fabricating bump electrodes with a leveling step for uniform heights

A method for fabricating a semiconductor device, wherein a number of bump electrodes have previously been formed on a surface of a multilayer circuit substrate for mounting a semiconductor element, bottoms of the bump electrodes being connected to via hole conductors buried in the multilayer circuit substrate,

• the method comprising:
• applying a conductive adhesive to tops of the bump electrodes on the surface of the multilayer circuit substrate to form end portions of the conductive adhesive;
• semi-curing the conductive adhesive into a B-staged state;
• pressing the end portions of the conductive adhesive on the bump electrodes onto a flat surface to level the end portions of the conductive adhesive to a uniform height;
• applying an anisotropic conductive film on the surface of the multilayer substrate so as to embed the bump electrodes therein;
• pressing a semiconductor element to the anisotropic conductive film such that the electrode faces of the semiconductor element coincide with the end portions on the tops of the bump electrodes;
• and
• curing the conductive film to connect the electrode faces to the end portions on the tops of the bump electrodes electrically through the conductive film.