Embodiments of the present disclosure relate to an alloy as a brazing alloy for an electric switch braze joint, an electric switch braze joint, an electric switch and a method of producing an electric switch braze joint. The alloy composition of said the alloy consists of at least one element selected from each of group I and group II listed below, and a balance of impurities, Ag, and at least one of Cu, and Zn. Group I encompasses Cd, Mn, Ni, P, Sb, Si, Sn, Ti, and oxides thereof in a total amount of 0.5 to 45.0 wt. %. Group II encompasses Bi, Mo, Te, W, and oxides thereof, oxides of Cu and Zn in a total amount of 0.1 to 15.0 wt. %.

A lead-free solder preform includes a core layer and adhesion layer coated over surfaces of the core layer, where the preform delivers the combined merits from constituent solder alloys of the core and adhesion layers to provide both high temperature performance and improved wetting in high-temperature solder applications such as die attach. The core layer may be formed of a Bi Alloy having a solidus temperature above 260 C., and the adhesion layer may be formed of Sn, a Sn alloy, a Bi alloy, In, or an In alloy having a solidus temperature below 245 C. The solder preform may be formed using techniques such as: (1) electroplating a core ribbon with an adhesion material, (2) cladding an adhesion material foil onto a core ribbon, and/or (3) dipping a core ribbon in a molten adhesion alloy bath to allow thin layers of adhesion material to adhere to a core ribbon.

A solder alloy includes an alloy composition consisting of 35 to 68 mass % of Bi, 0.5 to 3.0 mass % of In, 0.01 to 0.10 mass % of Pd, and a balance of Sn. A solder paste includes a solder alloy comprising an alloy composition consisting of 35 to 68 mass % of Bi, 0.5 to 3.0 mass % of In, 0.01 to 0.10 mass % of Pd, and a balance of Sn. A solder ball includes a solder alloy comprising an alloy composition consisting of 35 to 68 mass % of Bi, 0.5 to 3.0 mass % of In, 0.01 to 0.10 mass % of Pd, and a balance of Sn.

The present invention provides a solder alloy, a solder paste, a solder ball, a resin flux-cored solder and a solder joint, both of which has the low-melting point to suppress the occurrence of the fusion failure, improves the ductility and the shear strength, and has excellent heat-cycle resistance. The solder alloy comprises an alloy composition composed of 35 to 68 mass % of Bi, 0.1 to 2.0 mass % of Sb, 0.01 to 0.10 mass % of Ni, and a balance of Sn. The alloy composition may contain at least one of Co, Ti, Al and Mn in total amount of 0.1 mass % or less. The solder alloy may be suitably used for a solder paste, a solder ball, a resin flux-cored solder and a solder joint.

Implementations of the disclosure are directed to a lead-free mixed solder powder paste suitable for low temperature to middle temperature soldering applications. The lead-free solder paste may consist of: an amount of a first solder alloy powder between 44 wt % and 83 wt %, the first solder alloy powder comprising Sn; an amount of a second solder alloy powder between 5 wt % to 44 wt %, the second alloy powder comprising Sn, where the first solder alloy powder has a liquidus temperature lower than a solidus temperature of the second solder alloy powder; and a remainder of flux. The solder paste may be used for reflow at a peak temperature below the solidus temperature of the higher solidus temperature solder powder but above the melting temperature of the lower solidus temperature one.

A solder alloy has an alloy composition consisting of, in mass %, Ag: from 3.2 to 3.8%, Cu: from 0.6 to 0.8%, Ni: from 0.01 to 0.2%, Sb: from 2 to 5.5%, Bi: from 1.5 to 5.5%, Co: from 0.001 to 0.1%, Ge: from 0.001 to 0.1%, and optionally at least one of Mg, Ti, Cr, Mn, Fe, Ga, Zr, Nb, Pd, Pt, Au, La and Ce: 0.1% or less in total, with the balance being Sn. The alloy composition satisfies the following relationship (1): 2.93{(Ge/Sn)+(Bi/Ge)}(Bi/Sn) (1). In the relationship (1), each of Sn, Ge, and Bi represents the content (mass %) in the alloy composition.

Paste compositions comprising 40-70 percent by weight (wt %) of a low melting point (LMP) particle composition comprising Y; 25-65 wt % of a high melting point (HMP) particle composition comprising M; and 1-15 wt % of a fluxing vehicle. The reaction products formed between M and Y are crystalline intermetallics that are solids at temperature T1 and the surface area of said HMP particle composition is in the range of 0.07 to 0.18 square meters per gram of Y in said composition. Also provided are methods of contacting electronic compositions using the paste compositions.

The present disclosure relates to a lead-free solder alloy composition in which a nanosized ceramic powder additive is added to a lead-free solder alloy of SnCuBi, SnAgBi or SnAgCuBi, and a method for preparing the same.

Provided is low alpha-ray emitting bismuth having an alpha dose of 0.003 cph/cm.sup.2 or less. Additionally provided is a method of producing low alpha-ray emitting bismuth, wherein bismuth having an alpha dose of 0.5 cph/cm.sup.2 or less is used as a raw material, the raw material bismuth is melted in a nitric acid solution via electrolysis to prepare a bismuth nitrate solution having a bismuth concentration of 5 to 50 g/L and a pH of 0.0 to 0.4, the bismuth nitrate solution is passed through a column filled with ion-exchange resin to eliminate polonium contained in the solution by an ion-exchange resin, and bismuth is recovered by means of electrowinning from the solution that was passed through the ion-exchange resin. Recent semiconductor devices are of high density and high capacity, and therefore are subject to increased risk of soft errors caused by the effects of alpha rays emitted from materials in the vicinity of semiconductor chips. In particular, there is a strong demand for higher purification of solder materials used near semiconductor devices, and there is a demand for low alpha-ray emitting materials. Therefore, the present invention aims to elucidate the phenomenon of alpha ray generation from bismuth, and to provide a low alpha-ray emitting, high-purity bismuth that can be applied to the required materials and a production method thereof, as well as to provide an alloy of low alpha-ray emitting bismuth and tin and a production method thereof.

The present invention relates to a metal paste including: a first metal powder including nickel (Ni); a second metal powder including at least one selected from the group consisting of tin (Sn), zinc (Zn), bismuth (Bi), and indium (In); and a dispersing agent, and to a thermoelectric module which adopts a bonding technique using the metal paste.