Senju Metal Industry Co., Ltd.

Akiko Takaki

Tomoko Nagai

Kazuyori Takagi

Nanako Miyagi

Kenta Inoue

Hiroyoshi Kawasaki

Masato Shiratori

Kazuya Kitazawa

Yutaka Hashimoto

Kazuhiro Minegishi

Rina Horikoshi

Ryuichi Tsuda

Teppei Otsuki

The present invention uses a flux containing a rosin, a solvent, a thixo agent, and an activator. The thixo agent contains a polyamide and a compound represented by general formula (1). The polyamide is a condensate between an amine and at least one selected from aliphatic carboxylic acids and hydroxy group-containing aliphatic carboxylic acids, and has an endothermic peak at a temperature of 120-200° C. In the general formula, Rrepresents a hydrocarbon group having 11-30 carbon atoms. Rrepresents a hydrogen atom or a hydrocarbon group having 12-31 carbon atoms. Rrepresents an n-valent hydrocarbon group having 4-12 carbon atoms. Rrepresents an alkylene group having 2-6 carbon atoms. Rrepresents a single bond or an alkylene group having 2-6 carbon atoms. n represents 1 or 2. When n represents 1, m represents an integer of 1-3. When n represents 2, m represents 1.

Flux and solder paste

The present invention employs a flux which contains rosin, a solvent, a thixotropic agent and an activator. The thixotropic agent contains a polyamide (PA2). The PA2 is a condensation product of an aliphatic carboxylic acid, a hydroxy group-containing aliphatic carboxylic acid and an aliphatic amine having from 3 to 10 carbon atoms; and the aliphatic carboxylic acid includes an aliphatic dicarboxylic acid having from 11 to 20 carbon atoms. With respect to the endothermic amount calculated from the peak area of the differential scanning calorimetry curve of PA2 as obtained by differential scanning calorimetry measurement, the ratio of the endothermic amount within the range of from 50° C. to 190° C. to the total endothermic amount within the range of from 50° C. to 200° C. is 90% or more.

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.

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Tokyo, Japan

Akiko Takaki