An arc welding solid wire includes: a steel material; and a copper plating layer formed on a surface of the steel material, in which an amount of Cu in the steel material and the copper plating layer is 0.05 mass % to 0.30 mass % with respect to a total mass of the wire, a surface of the wire is coated with 0.05 g to 0.20 g of oil with respect to 1 kg of the wire, and on a surface of the copper plating layer, an arithmetic average roughness Rac in a circumferential direction is 0.25 .Math.m to 1.00 .Math.m, and an arithmetic average roughness Ral in a longitudinal direction is 0.07 .Math.m to 0.50 .Math.m.

Provided is a metal particle for adhesive paste. The metal particle may include a core including at least one metal; and a shell on at least one surface of the core and including at least one metal and nanoparticles. The metal particle may be a transient liquid phase particle and the at least one metal of the core may have a higher melting point than a melting point of the at least one metal of the shell. In addition, provided are a method of preparing the metal particle for adhesive paste, a composite bonding structure formed from the metal particle for adhesive paste, and a semiconductor device including the composite bonding structure.

A TIG welding flux for dissimilar steels is used to solve the problem that the conventional friction stir welding procedure for butt-joint welding a stainless steel workpiece and a carbon steel workpiece cannot be used on site, as well as the problem that the increased operating time and manufacturing cost due to forming bevel faces on both the stainless steel workpiece and the carbon steel workpiece. The TIG welding flux for dissimilar steels includes 25-35 wt % of silicon dioxide (SiO.sub.2), 20-30 wt % of cobalt (II, III) oxide (Co.sub.3O.sub.4), 15-20 wt % of manganese (II, III) oxide (Mn.sub.3O.sub.4), 10-15 wt % of nickel (III) oxide (Ni.sub.2O.sub.3), 7-12 wt % of molybdenum trioxide (MoO.sub.3), 6-11 wt % of manganese (II) carbonate (MnCO.sub.3), 5-10 wt % of nickel (II) carbonate (NiCO.sub.3), and 2-4 wt % of aluminum fluoride (AlF.sub.3).

An objective of the present invention is to provide a flux that suppresses occurrence of flux drying up during soldering and occurrence of precipitation during storing.

The flux comprising, based on the whole flux, 3.5 to 11% by mass of a rosin ester, more than 0% by mass and 18% by mass or less of a rosin resin other than a rosin ester, and 70% by mass or more and less than 96.5% by mass of a solvent.

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.

A Magnetic-field melting preform solder that melts by action of an AC magnetic field, wherein the preform solder includes a laminated structure made up of two or more layers, at least two layers constituting the laminated structure is made up of solder material, the at least two layers do not contain ferromagnetic material, each of the at least two layers includes a surface facing with each other, and the surfaces facing with each other are in contact with each other. A bonding method using the preform solder includes a providing the preform solder between an electrode on a substrate and an electrode of an electronic component, and bonding together the electrode on the substrate and the electrode of the electronic component by generating an AC magnetic field around the substrate and thereby melting the preform solder.

A coating composition for a heat exchanger tube including vanadium (V), a flux, and a binder, wherein the vanadium is included in an amount of 28 to 38 parts by weight with respect to 100 parts by weight of the composition, and a coating method of a heat exchanger tube using the same are provided.

A resin flux solder paste includes a solder powder, and a flux, in which the flux contains at least an epoxy resin, a curing agent, a curing accelerator, and an activator, the epoxy resin contains 10% to 90% by weight of one or more of a biphenyl aralkyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene type epoxy resin, having an epoxy equivalent of 200 to 400, with respect to a total amount of the epoxy resin, and the curing agent contains 30% to 95% by weight of a biphenyl aralkyl phenol resin having a hydroxyl group equivalent of 150 to 350 with respect to a total amount of the curing agent, and 5% to 70% by weight of a phenol novolac resin having an allyl group having a hydroxyl group equivalent of 100 to 200 with respect to the total amount of the curing agent.

A metal composition that includes a metal component and a flux. The metal component is composed of a first metal powder of a Sn-based metal, and a second metal powder of a Cu-based metal that has a higher melting point than the Sn-based metal. The flux includes a rosin, a solvent, a thixotropic agent, an activator, and the like. When the metal composition is heated to a temperature equal to or higher than the melting point of the first metal powder, the first metal powder is melted. The melted Sn and the CuNi alloy powder produce an intermetallic compound phase of a CuNiSn alloy through a TLP reaction.

A metal composition that includes a metal component and a flux. The metal component is composed of a first metal powder of a Sn-based metal, and a second metal powder of a Cu-based metal that has a higher melting point than the Sn-based metal. The flux includes a rosin, a solvent, a thixotropic agent, an activator, and the like. When the metal composition is heated to a temperature equal to or higher than the melting point of the first metal powder, the first metal powder is melted. The melted Sn and the CuNi alloy powder produce an intermetallic compound phase of a CuNiSn alloy through a TLP reaction.