FLUX-APPLYING METHOD, FLOW SOLDERING METHOD, DEVICE FOR THE SAME AND ELECTRONIC CIRCUIT BOARD

摘要

PROBLEM TO BE SOLVED: To reduce the occurrence of process defects caused by the residue of flux applied to a substrate adhering to a transportation member as foreign matters in the post process of a flow soldering process, in flux-applying method of the flow soldering process. SOLUTION: The flux-applying method is used for the flow soldering process for sure mounting of electronic components on the substrate by using a solder material. A flux supply means supplies flux from below the substrate and is applied to the lower face of the substrate. When the substrate (1) is positioned above the flux supply means (6), while the substrate (1) is transported, flux (3) is supplied to a lower face (11) of the substrate (1) from the flux supply means (6), in a state where respective edge parts are covered by a pair of covers (8a and 8b) positioned directly below a pair of edge parts of the lower face (11) of the substrate, which follow the transport direction (9) of the substrate. Then, flux is applied to the lower face of the substrate, except for a pair of edge parts.