To avoid cracking a conductive resin or forming defective connections at an interface to wiring electrodes, by executing inspection, sealing, and seal heating steps at specified high temp. after the connection step.

A method comprising steps of coating a conductive resin paint 54 on tops of bumps 51, connection the bumps 51 to wiring electrodes 53, tacking semiconductor devices 50 onto a wiring board 52, heating to cure the resin 54 to connect, coating a seal resin 55 while keeping hot, allowing for filing the coated resin 55 by a dispenser in the gap between the semiconductor device 50 and the wiring board 52 due to the capillary effect, and heating to cure wherein the process temp. from the heating end of the connection step to the seal heating and is kept at a temperature subtracting about 40°C from the glass transition temp. of the resin 54.