To provide a solder material capable of performing soldering with high reliability while suppressing materials other than a solder metal to remain inside the solder after the soldering. Coil-shaped carbons are heated by electromagnetic waves by using a solder material in which coil-shaped carbons of 0.5 weight % to 1.5 weight % with respect to a weight of a solder paste are mixed, thereby performing soldering by heating the solder material itself.

Embodiments describe high aspect ratio and fine pitch interconnects for a semiconductor package, such as a package-on-package structure. In an embodiment, the interconnects are formed with a no-slump solder paste. In an embodiment, the no-slump solder paste is printed in an uncured state, and is then cured with a liquid phase sintering process. After being cured, the no-slump solder paste will not reflow at typical processing temperatures, such as those below approximately 400° C. According to embodiments, the no-slump solder paste includes Cu particles or spheres, a solder matrix component, a polymeric delivery vehicle, and a solvent. In an embodiment, the liquid phase sintering produces a shell of intermetallic compounds around the Cu spheres. In an embodiment, the sintering process builds a conductive metallic network through the no-slump solder paste.

A solder alloy includes 1.1% by mass or more and 8% by mass or less of Cu; 6% by mass or more and 20% by mass or less of Sb; 0.01% by mass or more and 0.5% by mass or less of Ni; and 0.001% by mass or more and 1% by mass or less of Co; a balance being Sn. An amount of Cu (% by mass) and an amount of Ni (% by mass) satisfies following formula: the amount of Ni/(the amount of Cu+the amount of Ni)<0.10.

Provided is a solder material having oxidation resistance at the time of melting solder or after melting it, as well as managing a thickness of oxide film at a fixed value or less before melting the solder. A Cu core ball 1A is provided with a Cu ball 2A for keeping a space between a semiconductor package and a printed circuit board and a solder layer 3A that covers the Cu ball 2A. The solder layer 3A is composed of Sn or a solder alloy whose main component is Sn. For the Cu core ball 1A, lightness is equal to or more than 65 in the L*a*b* color space and yellowness is equal to or less than 7.0 in the L*a*b* color space, and more preferably, the lightness is equal to or more than 70 and the yellowness thereof is equal to or less than 5.1.

Rosin-free thermosetting flux formulations for enhancing the mechanical reliability of solder joints. In accordance with one or more aspects, a solder paste as shown and described herein imparts improved or enhanced solder joint properties relating to at least one of drop shock, thermal cycling, thermal shock, shear strength, flexural strength performance, and/or other thermal-mechanical performance attributes.

A method of assembling components, such as electronic components, onto a substrate, such as an electronic substrate, includes applying solder paste to an electronic substrate to form a solder paste deposit, placing a low temperature preform in the solder paste deposit, processing the electronic substrate at a reflow temperature of the solder paste to create a low temperature solder joint, and processing the low temperature solder joint at a reflow temperature that is lower than the reflow temperature of the solder paste. Other methods of assembling components and solder joint compositions are further disclosed.

The present invention addresses the problem of providing a composite nanometal paste which is relatively low in price and is excellent in terms of bonding characteristics, thermal conductivity, and electrical property. The present invention is a copper-filler-containing composite nanometal paste that contains composite nanometal particles each comprising a metal core and an organic coating layer formed thereon. The metal paste contains a copper filler and contains, as binders, first composite nanometal particles and second composite nanometal particles which differ from the first composite nanometal particles in the thermal decomposition temperature of the organic coating layer, wherein the mass proportion W1 of the organic coating layer in the first composite nanometal particles is in the range of 2-13 mass %, the mass proportion W2 of the organic coating layer in the second composite nanometal particles is in the range of 5-25 mass %, and these particles satisfy the relationships W1.

Provided is a high-temperature lead-free solder alloy having excellent tensile strength and elongation in a high-temperature environment of 250° C. In order to make the structure of an Sn—Sb—Ag—Cu solder alloy finer and cause stress applied to the solder alloy to disperse, at least one material selected from the group consisting of, in mass %, 0.003 to 1.0% of Al, 0.01 to 0.2% of Fe, and 0.005 to 0.4% of Ti is added to a solder alloy containing 35 to 40% of Sb, 8 to 25% of Ag, and 5 to 10% of Cu, with the remainder made up by Sn.

Provided is a silver powder which has an appropriate viscosity range at the time of paste production, can be easily kneaded, and prevents the occurrence of flakes. The silver powder to be used has a specific surface area ratio SA.sub.B/SA.sub.S of 0.5 to 0.9, wherein SA.sub.B is a specific surface area measured by the BET method, and SA.sub.S is a specific surface area calculated from a mean primary-particle diameter D.sub.S measured with a scanning electron microscope. Furthermore, the silver powder preferably has a degree of aggregation of 1.5 to 5.0, the degree being obtained in such a manner that a volume median diameter D.sub.50 measured by laser diffraction scattering is divided by the foregoing Ds.

The present invention provides a thick-film paste composition for printing the front side of a solar cell device having one or more insulating layers. The thick-film paste comprises an electrically conductive metal and a dual-frit oxide composition dispersed in an organic medium.