Abstract: Provided are: a resin composition for soldering use, which has excellent compatibility with a rosin-based resin and excellent temperature cycle reliability and is therefore suitable for a flux for soldering use; and a soldering composition and a flux cored solder, in each of which the resin composition for soldering use is used. The resin composition for soldering use comprises: an acrylic resin having a number average molecular weight of 500 or more and less than 2000 as determined by mass spectrometry using a time-of-flight mass spectrometer; and a rosin-based resin, a polyethylene-based resin or a polypropylene-based resin. Alternatively, the resin composition for soldering use comprises: an acrylic resin having a weight average molecular weight of 500 or more and less than 2000 as determined by mass spectrometry using a time-of-flight mass spectrometer; and a rosin-based resin, a polyethylene-based resin or a polypropylene-based resin.

Abstract: Provided is a flux which is rosin-free and contains 50% by mass or more and 90% by mass or less of 2,4-diethyl-1,5-pentanediol, more than 0% by mass and less than 50% by mass of a solvent, 1% by mass or more and 15% by mass or less of an organic acid, wherein the total amount of the 2,4-diethyl-1,5-pentanediol and the solvent is 83% by mass or more and 99% by mass or less. This flux does not require washing with an organic detergent when transferred to solder balls is provided.

Abstract: A resin composition for soldiering is provided. The resin composition includes 1 wt % or more and 40 wt % or less of a dimer acid, a trimer acid, or a combination thereof, 30 wt % or more and 99 wt % or less of a rosin, and 0 wt % or more and 13 wt % or less of a solvent. The dimer acid is selected from a dimer acid that is a reaction product of oleic acid and linoleic acid, a hydrogenated dimer acid obtained by adding hydrogen to a dimer acid that is a reaction product of oleic acid and linoleic acid, and a combination thereof. The trimer acid is selected from a trimer acid that is a reaction product of oleic acid and linoleic acid, a hydrogenated trimer acid obtained by adding hydrogen to a trimer acid that is a reaction product of oleic acid and linoleic acid, and a combination thereof.

Abstract: Provided are a solder alloy, which has excellent heat cycle characteristics and in which Cu erosion and yellowish discoloration are suppressed, and an increase in viscosity of a solder paste over time is suppressed, a solder paste, a solder ball, a solder preform, a solder joint, and a circuit. The solder alloy has an alloy composition consisting of, by mass %, 2.8% to 4% of Ag, 1.5% to 6% of Bi, 0.8% to 1.2% of Cu, 0.0040% to 0.025% of As, and a balance of Sn.

Abstract: A solder alloy is provided which suppresses the change in a solder paste over time, decreases the temperature difference between the liquidus-line temperature and the solidus temperature, and exhibits a high reliability. The solder alloy has an alloy constitution composed of: 10 ppm by mass or more and less than 25 ppm by mass of As; at least one selected from the group consisting of 0 ppm by mass to 10000 ppm by mass of Bi and 0 ppm by mass to 5100 ppm by mass of Pb; more than 0 ppm by mass and no more than 3000 ppm by mass of Sb; and a remaining amount of Sn; and satisfies both the formula (1) and the formula (2). 300?3As+Sb+Bi+Pb??(1) 0.1?{(3As+Sb)/(Bi+Pb)}×100?200??(2) In the formula (1) and the formula (2), As, Sb, Bi, and Pb each represents an amount thereof (ppm by mass) in the alloy constitution.

Abstract: A solder paste contains a flux and a metal powder, wherein the flux contains: 0.5% by mass to 20.0% by mass of a (carboxyalkyl)isocyanurate adduct; 5.0% by mass to 45.0% by mass of a rosin; and a solvent. The (carboxyalkyl)isocyanurate adduct is at least one selected from the group consisting of mono(carboxyalkyl)isocyanurate adducts, bis(carboxyalkyl)isocyanurate adducts and tris(carboxyalkyl)isocyanurate adducts.

Abstract: Provided are a solder alloy which has excellent temperature cycle characteristics and in which yellowish discoloration is suppressed, excellent wettability is maintained, and an increase in viscosity of a solder paste over time can be suppressed, and a solder paste, a solder ball, and a solder joint in which the solder alloy is used. The solder alloy consists of, by mass %, 1.0% to 5.0% of Ag, 0.5% to 3.0% of Cu, 0.5% to 7.0% of Sb, 0.0040% to 0.025% of As, and a balance of Sn.

Abstract: An object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy or the like which has a low melting point, excellent ductility, and high tensile strength, and in which if soldering is performed on a Cu electrode subjected to electroless Ni plating treatment, a solder joint formed through this soldering exhibits high shear strength. In addition, another object of the present invention is to provide an Sn—Bi—Cu—Ni solder alloy in which a solder joint formed through soldering exhibits high shear strength even for a Cu electrode which has not been subjected to plating treatment. Furthermore, still another object of the present invention is to provide, in addition to the above-described objects, a solder alloy or the like of which yellowish discoloration can be suppressed and in which change in viscosity of a solder paste over time can be suppressed. The solder alloy has an alloy composition consisting of, by mass %, 31% to 59% of Bi, 0.3% to 1.0% of Cu, 0.01% to 0.06% of Ni, 0.0040% to 0.

Abstract: Provided is flux that can be discharged using an inkjet method and that is capable of bonding to an adherend after application. This flux includes 5-50 mass % of a solid solvent having a melting point of 60° C. or less, 50-80 mass % of a solvent, 5-10 mass % of an organic acid, 10-30 mass % of an amine, and 0-5 mass % of a halide, the flux forming a liquid having a high viscosity of 5 Pa·s or higher at 25° C., and forming a liquid having a low viscosity of 50 mPa·s or less at 100° C.

Abstract: A flux in which solder wettability can be maintained and with which it is possible to suppress the amount of residue after soldering and realize low residue. This flux includes 65-99 wt % of a solvent, and also includes 1-13 wt % of at least one acid selected form a dimer acid that is a reaction product of oleic acid and linoleic acid; a trimer acid that is a reaction product of oleic acid and linoleic acid; a hydrogenated dimer acid obtained by hydrogenating dimer acid that is a reaction product of oleic acid and linoleic acid; and a hydrogenated trimer acid obtained by hydrogenating a trimer acid that is a reaction product of oleic acid and linoleic acid.

Abstract: A flux comprising an organic acid; a solvent; and polyoxyethylene behenyl alcohol having an average number of moles of ethylene oxide added of 7 to 40 mol.

Abstract: Provided are a Cu ball, an OSP-treated Cu ball, a Cu core ball, a solder joint, solder paste, and formed solder, which realize high sphericity and low hardness and in which discoloration is suppressed. An electronic component is configured by joining a solder bump of a semiconductor chip and an electrode of a printed circuit board with solder pastes The solder bump formed by joining a Cu ball to an electrode of the semiconductor chip. The Cu ball has a purity of 99.995% by mass or more and 99.9995% by mass or less, a total content of at least one element selected from Fe, Ag, and Ni of 5.0 ppm by mass or more and 50.0 ppm by mass or less, a content of S of 1.0 ppm by mass or less, and a content of P of less than 3.0 ppm by mass.

Abstract: Provided is a flux that includes a heat-resistant activator having low reactivity with thermosetting resins, and a solder paste in which the flux is used. The flux includes 5 wt % or more and 20 wt % or less of any one of a dimer acid, a trimer acid, a hydrogenated dimer acid obtained by hydrogenating the dimer acid, and a hydrogenated trimer acid obtained by hydrogenating the trimer acid, on in total, of two or more of a dimer acid, a trimer acid, a hydrogenated dimer acid obtained by hydrogenating the dimer acid, and a hydrogenated trimer acid obtained by hydrogenating the trimer acid; 30 wt % or more and 70 wt % or less of a thermosetting resin; and 3 wt % or more and 15 wt % or less of an amine. The solder paste includes solder powder and the flux.

Abstract: A solder alloy has an alloy composition of As: 25 mass ppm to 300 mass ppm, Bi: 0 mass ppm or more and 25000 mass ppm or less, and Pb: more than 0 mass ppm and 8000 mass ppm or less, with a balance being made up of Sn, the solder alloy satisfying Expression (1) and Expression (2) below, 275?2As+Bi+Pb ??(1) 0<2.3×10?4×Bi+8.2×10?4×Pb?7 ??(2) where in Expression (1) and Expression (2), As, Bi and Pb represent respectively contents (mass ppm) thereof in the alloy composition.

Abstract: A flux which imparts thixotropy, and which exhibits excellent printability, printing sagging-inhibiting ability, and heating sagging-inhibiting ability; and a solder paste which uses said flux. This flux includes a thixotropic agent, a rosin, an organic acid, and a solvent. The thixotropic agent includes a cyclic amide compound obtained by polycondensing a dicarboxylic acid and/or a tricarboxylic acid, and a diamine and/or a triamine into a cyclic shape; and an acyclic amide compound which is obtained by polycondensing a monocarboxylic acid, a dicarboxylic acid and/or a tricarboxylic acid into an acyclic shape. The flux includes at least 0.1 wt % but not more than 8.0 wt % of the cyclic amide compound, and at least 0.5 wt % but not more than 8.0 wt % of the acyclic amide compound. The total amount of the cyclic amide compound and the acyclic amide compound is at least 1.5 wt % but not more than 10.0 wt %.

Abstract: Provided are flux for resin flux cored solder, flux for flux-coated solder, resin flux cored solder using the flux for resin flux cored solder, flux-coated solder using the flux for flux-coated solder, and a soldering method, which have low residue and are excellent in processability. The flux for resin flux cored solder or flux-coated solder contains a solid solvent in an amount of 70 wt % or more and 99.5 wt % or less, and an activator in an amount of 0.5 wt % or more and 30 wt % or less.

Abstract: Provided are a flux composition that is applicable without any film formation step, and solder paste, a solder joint and a solder joining method using the flux composition. The flux composition contains 20 wt % or more and 50 wt % or less of an epoxy resin, 15 wt % or more and 45 wt % or less of diallyl bisphenol A, and 1 wt % or more and 30 wt % or less of organic acid.

Abstract: A solder alloy having an alloy composition including at least one of As: 25 to 300 mass ppm, Pb: more than 0 mass ppm and 5100 mass ppm or less, and Sb: more than 0 mass ppm and 3000 mass ppm or less, and moreover Bi: more than 0 mass ppm and 10000 mass ppm or less, as well as a balance including Sn, wherein expression (1) and expression (2) below are satisfied: 275?2As+Sb+Bi+Pb??(1) 0.01?(2As+Sb)/(Bi+Pb)?10.00??(2) where in the expression (1) and the expression (2), As, Sb, Bi, and Pb each represent a content (mass ppm) in the alloy composition.

Abstract: Provided is flux for resin flux cored solder using in a soldering method in which the resin flux cored solder is supplied into a through hole formed along a central axis of a soldering iron. The flux contains volatile rosin in an amount of 70 wt % or more and 98 wt % or less, non-volatile rosin in an amount of 0 wt % or more and 10% or less, and an activator in an amount of 2 wt % or more and 30 wt % or less, the activator including an organic acid in an amount of 0 wt % or more and 15 wt % or less, an organohalogen compound in an amount of 0.5 wt % and 15 wt % or less, an amine in an amount of 0 wt % or more and 5 wt % or less, and an amine hydrohalide salt in an amount of 0 wt % or more and 2.5 wt % or less.

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.