Flux for soldering and solder paste composition

A solder paste composition, comprising:

• a solder alloy powder;
• and
• a flux for soldering, comprising:
• a base resin containing an acrylic resin and a rosin, an amount of the rosin to be incorporated being from 0% by weight to 30% by weight with respect to a total amount of the base resin;
• a solvent;
• and
• an activating agent including a compound having a plurality of carboxyl groups on a cyclohexyl structure represented by a general formula (1)
• wherein X is (a) one or more carboxyl groups, or (b) one or more carboxyl groups and at least one selected from a hydrogen atom, chloro group, bromo group, alkyl group, and cyclohexyl group,
• a position of the X is not limited,
• a number of the X is one or more, and
• the X may have either one of the (a) and (b) alone, or a plurality of the (a) and (b) in combination, and
• wherein an amount of the activating agent to be incorporated is from 5% by weight to 15% by weight with respect to the total amount of the flux for soldering.