Abstract: A flux containing rosin, a solvent, a thixotropic agent, a thiol compound, and an activator, in which the thiol compound includes a compound (Tp) having a benzenethiol skeleton in which one or more hydrogen atoms on a benzene ring are substituted with a mercapto group (—SH), is provided in the present invention. As the compound (Tp), at least one thiol compound selected from the group consisting of 2-aminobenzenethiol, 4-aminobenzenethiol, 3-aminobenzenethiol, and benzenethiol is preferable. According to such flux, a change in viscosity of the solder paste with time can be further suppressed.

Abstract: A flux containing rosin, a solvent, a thixotropic agent, an amine hydroiodide, and an activator (provided that the amine hydroiodide is excluded), in which the amine hydroiodide includes a heteroalicyclic amine hydroiodide, is provided in the present invention. As the heteroalicyclic amine hydroiodide, at least one selected from the group consisting of piperidine hydroiodide and pipecholine hydroiodide is preferable. According to such flux, the generation of voids during soldering can be further suppressed.

Abstract: A flux containing rosin, a solvent, a thixotropic agent, a thiol compound, and an activator, in which the thiol compound includes a compound (Tp) having a benzenethiol skeleton in which one or more hydrogen atoms on a benzene ring are substituted with a mercapto group (—SH), is provided in the present invention. As the compound (Tp), at least one thiol compound selected from the group consisting of 2-aminobenzenethiol, 4-aminobenzenethiol, 3-aminobenzenethiol, and benzenethiol is preferable. According to such flux, a change in viscosity of the solder paste with time can be further suppressed.

Abstract: A flux containing rosin, a solvent, a thixotropic agent, an amine hydroiodide, and an activator (provided that the amine hydroiodide is excluded), in which the amine hydroiodide includes a heteroalicyclic amine hydroiodide, is provided in the present invention. As the heteroalicyclic amine hydroiodide, at least one selected from the group consisting of piperidine hydroiodide and pipecholine hydroiodide is preferable. According to such flux, the generation of voids during soldering can be further suppressed.

Abstract: An object of the present invention is to provide an electrically conductive paste and a sintered body thereof having a low electric resistance value and excellent electrical conductivity when made into a sintered body. An electrically conductive paste comprising: a flake-like silver powder having a median diameter D50 of 15 ?m or less; a silver powder having a median diameter D50 of 25 ?m or more; and a solvent, wherein the content of the flake-like silver powder is 15 to 70 parts by mass and the content of the silver powder having a median diameter D50 of 25 ?m or more is 30 to 85 parts by mass based on 100 parts by mass in total of the flake-like silver powder and the silver powder having a median diameter D50 of 25 ?m or more.

Abstract: A solder joint, for bonding an electrode of a circuit board to an electrode of an electronic component, that includes: an Sn—Bi-based solder deposited on the electrode of the circuit board; and a solder alloy deposited on the electrode of the electronic component. The Sn—Bi-based solder alloy has a lower melting point than the solder alloy deposited on the electrode of the electronic component. Fine Bi phases in the solder joint each have an area of less than or equal to 0.5 ?m2. Coarse Bi phases in the solder joint each have an area of greater than 0.5 ?m2 and less than or equal to 5 ?m2. A proportion of the fine Bi phases among the fine Bi phases and the coarse Bi phases is greater than or equal to 60%.

Abstract: A solder joint, for bonding an electrode of a circuit board to an electrode of an electronic component, that includes: an Sn—Bi-based solder deposited on the electrode of the circuit board; and a solder alloy deposited on the electrode of the electronic component. The Sn—Bi-based solder alloy has a lower melting point than the solder alloy deposited on the electrode of the electronic component. Fine Bi phases in the solder joint each have an area of less than or equal to 0.5 ?m2. Coarse Bi phases in the solder joint each have an area of greater than 0.5 ?m2 and less than or equal to 5 ?m2. A proportion of the fine Bi phases among the fine Bi phases and the coarse Bi phases is greater than or equal to 60%.

Abstract: A solder bonding method that bonds, using a solder joint, an electrode of a circuit board to an electrode of an electronic component includes: depositing, on the electrode of the circuit board, an Sn—Bi-based solder alloy with a lower melting point than a solder alloy deposited on the electrode of the electronic component; mounting the electronic component on the circuit board such that the Sn—Bi-based solder alloy contacts the solder alloy on the electrode of the electronic component; heating the circuit board to a peak temperature of heating of 150° C. to 180° C.; holding the peak temperature of heating at a holding time of greater than 60 seconds and less than or equal to 150 seconds; and cooling, after the heating and to form the solder joint, the circuit board at a cooling rate greater than or equal to 3° C./sec.

Abstract: An object of the present invention is to provide an electrically conductive paste and a sintered body thereof having a low electric resistance value and excellent electrical conductivity when made into a sintered body. An electrically conductive paste comprising: a flake-like silver powder having a median diameter D50 of 15 ?m or less; a silver powder having a median diameter D50 of 25 ?m or more; and a solvent, wherein the content of the flake-like silver powder is 15 to 70 parts by mass and the content of the silver powder having a median diameter D50 of 25 ?m or more is 30 to 85 parts by mass based on 100 parts by mass in total of the flake-like silver powder and the silver powder having a median diameter D50 of 25 ?m or more.

Abstract: A metal sintered bonding body bonds a substrate and a die. In the metal sintered bonding body, at least a center part and corner part of a rectangular region where the metal sintered bonding body faces the die have a low-porosity region whose porosity is lower than an average porosity of the rectangular region. The low-porosity region is located within a strip-shaped region whose central lines are diagonal lines of the rectangular region.

Abstract: A metal sintered bonding body bonds a substrate and a die. In the metal sintered bonding body, at least a center part and corner part of a rectangular region where the metal sintered bonding body faces the die have a low-porosity region whose porosity is lower than an average porosity of the rectangular region. The low-porosity region is located within a strip-shaped region whose central lines are diagonal lines of the rectangular region.

Abstract: A solder bonding method that bonds, using a solder joint, an electrode of a circuit board to an electrode of an electronic component includes: depositing, on the electrode of the circuit board, an Sn—Bi-based solder alloy with a lower melting point than a solder alloy deposited on the electrode of the electronic component; mounting the electronic component on the circuit board such that the Sn—Bi-based solder alloy contacts the solder alloy on the electrode of the electronic component; heating the circuit board to a peak temperature of heating of 150° C. to 180° C.; holding the peak temperature of heating at a holding time of greater than 60 seconds and less than or equal to 150 seconds; and cooling, after the heating and to form the solder joint, the circuit board at a cooling rate greater than or equal to 3° C./sec.

Abstract: Provided is a flux for a solder paste that can prevent peeling from electrode, which is seen in a component, a thickness of which is reduced, such a semiconductor package like BGA. Rosin, a glycol-ether-based solvent, an organic acid, a thixotropic agent, a halogen compound, and an imidazole compound are contained and the halogen compound is either an amine hydrohalide or an organohalogen compound or a combination of them. Their addition amounts stay within a range satisfying a formula of 2.5-X-0.625Y?0 in which the addition amount of the amine hydrohalide is indicated by X (weight %) and the addition amount of the organohalogen compound is indicated by Y (weight %). However, the addition amount X of the amine hydrohalide and the addition amount Y of the organohalogen compound are such that 0?X?2.5 and 0?Y?4, excluding a range of 0?X<0.02 and 0?Y<0.1.