| abstract |
A flux containing an activator having low reactivity with a thermosetting resin and having heat resistance, and a solder paste using the flux are provided. The flux is hydrogen to dimer acid, a reaction product of oleic acid and linoleic acid, trimer acid, which is a reaction product of oleic acid and linoleic acid, hydrogenated dimer acid, which is a reaction product of oleic acid and linoleic acid, and trimer acid, which is a reaction product of oleic acid and linoleic acid. Any of the added hydrogenated trimer acids, or dimer acid as a reaction product of oleic acid and linoleic acid, trimer acid as a reaction product of oleic acid and linoleic acid, hydrogenated dimer acid in which hydrogen is added to dimer acid as a reaction product of oleic acid and linoleic acid, and oleic acid and linoleic acid The total of two or more types of hydrogenated trimer acids obtained by adding hydrogen to the trimer acid as a reactant of 5 wt% or more and 20 wt% or less, 30 wt% or more and 70 wt% or less of the thermosetting resin, and 3 wt% or more and 15 wt% or less of the amine are included. |