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.

A lead-free solder ball is provided which suppresses interfacial peeling in a bonding interface of a solder ball, fusion defects which develop between the solder ball and solder paste, and which can be used both with Ni electrodes plated with Au or the like and Cu electrodes having a water-soluble preflux applied atop Cu. The lead-free solder ball for electrodes of BGAs or CSPs consists of 1.6-2.9 mass % of Ag, 0.7-0.8 mass % of Cu, 0.05-0.08 mass % of Ni, and a remainder of Sn. It has excellent resistance to thermal fatigue and to drop impacts regardless of the type of electrodes of a printed circuit board to which it is bonded, which are Cu electrodes or Ni electrodes having Au plating or Au/Pd plating as surface treatment.

A lead-free solder ball is provided which suppresses interfacial peeling in a bonding interface of a solder ball, fusion defects which develop between the solder ball and solder paste, and which can be used both with Ni electrodes plated with Au or the like and Cu electrodes having a water-soluble preflux applied atop Cu. The lead-free solder ball for electrodes of BGAs or CSPs consists of 1.6-2.9 mass % of Ag, 0.7-0.8 mass % of Cu, 0.05-0.08 mass % of Ni, and a remainder of Sn. It has excellent resistance to thermal fatigue and to drop impacts regardless of the type of electrodes of a printed circuit board to which it is bonded, which are Cu electrodes or Ni electrodes having Au plating or Au/Pd plating as surface treatment.

Provided is a lead-free solder alloy that has excellent tensile strength and ductility, does not deform after heat cycles, and does not crack. The In and Bi content are optimized and the Sb and Ni content are adjusted. As a result, this solder alloy has an alloy composition including, by mass, 1.0 to 7.0% of In, 1.5 to 5.5% of Bi, 1.0 to 4.0% of Ag, 0.01 to 0.2% of Ni, and 0.01 to 0.15% of Sb, with the remainder made up by Sn.

Provided is a lead-free solder alloy that has excellent tensile strength and ductility, does not deform after heat cycles, and does not crack. The In and Bi content are optimized and the Sb and Ni content are adjusted. As a result, this solder alloy has an alloy composition including, by mass, 1.0 to 7.0% of In, 1.5 to 5.5% of Bi, 1.0 to 4.0% of Ag, 0.01 to 0.2% of Ni, and 0.01 to 0.15% of Sb, with the remainder made up by Sn.

The present invention provides a tin alloy bath for a float bath, an apparatus for manufacturing a float glass, a method for manufacturing a float glass that can provide a high quality float glass in which defects due to coagulation and falling of a volatile tin component have been suppressed, and a float glass manufactured using those. The above-mentioned tin alloy bath for a float bath is a molten metal bath to be placed in the float bath for supplying molten glass to a liquid surface of the molten metal bath, thereby forming into a glass ribbon, and includes 1 mass % or more of copper with the remainder being unavoidable impurities and tin.

The present invention provides a tin alloy bath for a float bath, an apparatus for manufacturing a float glass, a method for manufacturing a float glass that can provide a high quality float glass in which defects due to coagulation and falling of a volatile tin component have been suppressed, and a float glass manufactured using those. The above-mentioned tin alloy bath for a float bath is a molten metal bath to be placed in the float bath for supplying molten glass to a liquid surface of the molten metal bath, thereby forming into a glass ribbon, and includes 1 mass % or more of copper with the remainder being unavoidable impurities and tin.

PROBLEM: To provide a multi-layer preform sheet capable of forming a highly reliable and high-quality electric interconnect, an electro-conductive bonding portion and so forth that are less likely to produce the Kirkendall void.

SOLUTION: A multi-layer preform sheet having at least a first layer and a second layer, the first layer being composed of a solder material that contains an intermetallic compound, and the second layer containing a first metal having a melting point of 300° C. or above, and a second metal capable of forming an intermetallic compound with the first metal.

Solder paste consisting of 85 to 92% by weight of a tin-based solder and 8 to 15% by weight of a flux, wherein the flux comprises i) 30 to 50% by weight, based on its total weight, of a combination of at least two optionally modified natural resins, ii) 5 to 20% by weight, based on its total weight, of at least one low-molecular carboxylic acid; and iii) 0.4 to 10% by weight, based on its total weight, of at least one amine, and wherein the combination of the optionally modified natural resins has an integral molecular weight distribution of 45 to 70% by area in the molecular weight range of 150 to 550 and of 30 to 55% by area in the molecular weight range of >550 to 10,000 in the combined GPC.

Solder paste consisting of 85 to 92% by weight of a tin-based solder and 8 to 15% by weight of a flux, wherein the flux comprises i) 30 to 50% by weight, based on its total weight, of a combination of at least two optionally modified natural resins, ii) 5 to 20% by weight, based on its total weight, of at least one low-molecular carboxylic acid; and iii) 0.4 to 10% by weight, based on its total weight, of at least one amine, and wherein the combination of the optionally modified natural resins has an integral molecular weight distribution of 45 to 70% by area in the molecular weight range of 150 to 550 and of 30 to 55% by area in the molecular weight range of >550 to 10,000 in the combined GPC.