Method for forming solder bump and method for mounting semiconductor device using a solder powder resin composition

A method for forming solder bumps on terminals of an electronic component having a plurality of terminals on an upper surface of the electronic component, comprising the steps of:

• preparing a flat plate including a lower surface, the lower surface having a plurality of projections or recesses disposed thereon and a flat portion on which the plurality of projections or recesses are not disposed;
• supplying a resin composition including a solder powder to the upper surface of said electronic component;
• aligning the lower surface of the flat plate to oppose the upper surface of said electronic component;
• bringing the lower surface of the flat plate into contact with the resin so that the flat portion and the plurality of projections or recesses make contact with the resin thereby spreading the resin composition between the upper surface and the lower surface while the flat portion does not contact the upper surface;
• forming solder bumps on the terminals by melting the solder powder included in the resin composition by annealing of the resin composition and by allowing the melted solder powder to self-assemble on the terminals for growing the melted solder powder up to a level of a surface of said flat plate;
• and
• removing the flat plate after cooling and solidifying the solder bumps,
• wherein in the step of forming solder bumps, the solder bumps having pits corresponding to the projections or protrusions corresponding to the recesses are formed.