Flux, solder paste and method for producing soldered product

A solder paste comprising:

• a flux for soldering, comprising:
• 10 to 40 wt % of coumarin;
• 5 to 30 wt % of a monoamide-based thixotropic agent;
• and
• 40 to 80 wt % of a solvent;
• and
• a solder powder.

A method for producing a soldered product, comprising:

• supplying a solder paste comprising:
• a flux for soldering, comprising:
• 10 to 40 wt % of coumarin;
• 5 to 30 wt % of a monoamide-based thixotropic agent;
• and
• 40 to 80 wt % of a solvent;
• and
• a solder powder
• to a soldering portion of an electronic circuit board;
• mounting an electronic component onto the soldering portion;
• and
• heating the soldering portion up to a temperature at which the solder powder melts in a reducing atmosphere containing a reducing gas to join the electronic component and the electronic circuit board.