Method of soldering electronic component having solder bumps to substrate

摘要

A method of soldering electronic component (6) having solder bumps (7) formed thereon to substrate (12), wherein bumps (7) are pressed against a flux transferring stage on which a thin film is formed of flux (10) containing metal powder (16) of good wettability to solder so as to cause metal powder (16) to penetrate oxide films (7a) and embed in the surfaces on the bottom parts of bumps (7), and bumps (7) in this state are positioned and mounted to electrodes (12a) on substrate (12). Substrate (12) is then heated to melt bumps (7) and allow the melted solder to flow and spread along the surfaces of metal powder (16) toward electrodes (12a). The method can thus provide solder bonding portions of high quality without any soldering defect and deterioration of the insulating property.