Abstract: Provided are flux in which solder wettability is improved, and a solder paste in which the flux is used. The flux contains 0.5-20.0 wt % of a (carboxyalkyl)isocyanurate adduct, and 5.0-45.0 wt % of a rosin, and furthermore contains a solvent. The (carboxyalkyl)isocyanurate adduct is a mono(carboxyalkyl)isocyanurate adduct, a bis(carboxyalkyl)isocyanurate adduct, a tris(carboxyalkyl)isocyanurate adduct, or a combination of two or more of these.

Abstract: A flux containing an organic acid, a water-soluble base agent, and a solvent, but not containing water is adopted. In this flux, the organic acid includes 1,2,3-propanetricarboxylic acid. The water-soluble base agent is one or more selected from the group consisting of a nonionic surfactant and a weak cationic surfactant. The content of the 1,2,3-propanetricarboxylic acid is 1% by mass or more and 15% by mass or less with respect to the total amount of the entire flux, the total content of the water-soluble base agent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux, and the total content of the solvent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux. According to this flux, the wettability of solder can be enhanced and ball missing after reflow and flux residue washing is suppressed.

Abstract: A flux containing an organic acid, a water-soluble base agent, and a solvent, but not containing water is adopted. In this flux, the organic acid includes 1,2,3-propanetricarboxylic acid. The water-soluble base agent is one or more selected from the group consisting of a nonionic surfactant and a weak cationic surfactant. The content of the 1,2,3-propanetricarboxylic acid is 1% by mass or more and 15% by mass or less with respect to the total amount of the entire flux, the total content of the water-soluble base agent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux, and the total content of the solvent is 30% by mass or more and 65% by mass or less with respect to the total amount of the entire flux. According to this flux, the wettability of solder can be enhanced and ball missing after reflow and flux residue washing is suppressed.

Abstract: A flux containing an organic acid, an acrylic resin, a rosin, a thixotropic agent, and a solvent, but not containing water is adopted. In this flux, the organic acid includes 1,2,3-propanetricarboxylic acid, and the content of the 1,2,3-propanetricarboxylic acid is 0.1% by mass or more and 15% by mass or less with respect to the total amount of the entire flux. According to this flux, the wettability of solder can be enhanced, temperature cycle reliability is excellent, and scattering due to heating during reflow can be suppressed.

Abstract: It is an object of the present invention to provide a flux containing flux components homogeneously dispersed without precipitation of aggregates in addition to having an appropriate balance between fluidity and shape retention property, and a solder paste. A flux comprising 0.5 to 3.5 mass % of a sorbitol-type thixotropic agent selected from the group consisting of dibenzylidene sorbitol, bis(4-methylbenzylidene)sorbitol and a combination thereof, and 2 to 350 mass ppm of a sorbitol-type additive selected from the group consisting of sorbitol, monobenzylidene sorbitol, mono(4-methylbenzylidene)sorbitol and a combination thereof, and a glycol ether-type solvent.

Abstract: Provided are flux in which solder wettability is improved, and a solder paste in which the flux is used. The flux contains 0.5-20.0 wt % of a (2-carboxyalkyl)isocyanurate adduct, and 5.0-45.0 wt % of a rosin, and furthermore contains a solvent. The (2-carboxyalkyl)isocyanurate adduct is a mono(2-carboxyalkyl)isocyanurate adduct, a bis(2-carboxyalkyl)isocyanurate adduct, a tris(2-carboxyalkyl)isocyanurate adduct, or a combination of two or more of these.

Abstract: It is an object of the present invention to provide a flux containing flux components homogeneously dispersed without precipitation of aggregates in addition to having an appropriate balance between fluidity and shape retention property, and a solder paste. A flux comprising 0.5 to 3.5 mass % of a sorbitol-type thixotropic agent selected from the group consisting of dibenzylidene sorbitol, bis(4-methylbenzylidene)sorbitol and a combination thereof, and 2 to 350 mass ppm of a sorbitol-type additive selected from the group consisting of sorbitol, monobenzylidene sorbitol, mono(4-methylbenzylidene)sorbitol and a combination thereof, and a glycol ether-type solvent.

Abstract: The invention has an object to provide a flux for rapid heating method used in the rapid heating method such as a laser reflow, the flux being able to suppress any scattering of the solder alloy, and a solder paste for the rapid heating method. The flux contains rosin, a glycol-ether-based solvent, an organic acid, and a thixotropic agent, wherein the solvent is a glycol-based solvent having a low boiling point that is not more than 200 degrees C., content of the solvent having the low boiling point is not less than 20 weight % to not more than 40 weight %. The solder paste is obtained by mixing this flux with solder alloy powder. When the solvent having a high boiling point that is more than 200 degrees C. is further contained, the solvent having the low boiling point of not less than 60 weight % in relation to the whole of the solvent is contained.