| abstract |
A solder paste capable of obtaining excellent wettability even when a specific solder alloy containing a predetermined amount of Sb and Bi is used, and suppressing voids (voids), and the solder paste To provide an electronic circuit board in which the flux used for the soldering and the solder paste are used. In a solder paste containing a solder powder comprising a tin-silver-copper solder alloy and a flux, the tin-silver-copper solder alloy contains bismuth and antimony, and a tin-silver-copper system. The content of bismuth is 2.5% by mass or more with respect to the total amount of the solder alloy, the content of antimony is 2.5% by mass or more, and the flux includes succinic acid and / or glutaric acid, Containing imidazole having two or more aromatic rings and / or imidazoline having one or more aromatic rings. [Selection figure] None |