A flux composition includes a component (A) that is a powder of an alkali metal zinc fluoroaluminate represented by “M.sub.wZn.sub.xAl.sub.yF.sub.z (1)” (wherein M is K or Cs, and w, x, y, and z are a positive integer, the greatest common divisor of w, x, y, and z being 1), the content of the component (A) in the flux composition being 50 mass % or more. The flux composition prevents occurrence of a brazing defect and discoloration even when an aluminum alloy is brazed in an atmosphere having a high oxygen concentration, or an atmosphere having high humidity.

The disclosed apparatus, systems and methods relate to the design principles for forming a welded joint between two sections of tubing or pipe. The material at the end portion of a first section of tubing to is folded inwardly to create a support surface. This support surface improves the ability to weld light gage material with traditional arc welding and it creates conditions to allow brazing to be as strong as traditional arc welding by using A shaped piece of filler material which is located at the intersection between the support surface of the first section of tubing and a side wall section of the second section of tubing. While holding together the first and second sections of tubing with the filler material, heat is applied at the intersection at a temperature and for a duration sufficient to melt the filler material and form the 3t joint.

A processor receives solder paste information, where the solder paste information describes a solder paste used in assembly of a printed circuit board. A processor determines a minimum magnetic force required for removing the solder paste from the printed circuit board based on the solder paste information. A processor receives electromagnet information, where the electromagnet information describes an electromagnet used in cleaning of a misprint of the solder paste on the printed circuit board. A processor determines a minimum amount of power to provide the electromagnet to induce the minimum magnetic force in the electromagnet, where the determination of the amount of power is based on the electromagnet information and the minimum magnetic force. A processor adjusts an amount of power applied to the electromagnet to at least the determined minimum amount of power to clean the misprint of the solder paste from the printed circuit board.

A method for manufacturing a power module substrate includes a first lamination step of laminating a ceramic substrate and a copper sheet through an active metal material and a filler metal having a melting point of 660° C. or lower on one surface side of the ceramic substrate; a second lamination step of laminating the ceramic substrate and an aluminum sheet through a bonding material on the other surface side of the ceramic substrate; and a heating treatment step of heating the ceramic substrate, the copper sheet, and the aluminum sheet laminated together, and the ceramic substrate and the copper sheet, and the ceramic sheet and the aluminum sheet are bonded at the same time.

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.

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.

Bulk copper solder is highly desired as a solder compound because it is very electrically conductive and has a high melting point relative to other solders. A composition for a copper solder includes copper(II) oxide powder in the range of 37-53% by mass, silicon carbide (SiC) powder in the range of 8-14% by mass, and a flux in the range of 35%-53% by mass. Energy in the form of microwave energy can be applied to the copper solder to convert the Cu(II)O to Cu, for a Cu product conversion of >93%.

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.

A method of joining an aluminum workpiece and an adjacent overlapping steel workpiece by reaction metallurgical joining, and the resultant metallurgical joint formed between the two workpieces, are disclosed. The method involves compressing a reaction material located between the aluminum and steel workpieces and heating the reaction material momentarily to form a metallurgical joint that comprises bonding interface between the reaction material and the steel workpiece and a bonding interface between the reaction material and the aluminum workpiece. The reaction material is formulated to be able to interact with both aluminum and steel in order to establish the bonding interfaces of the metallurgical joint. Moreover, the practice of oscillating wire arc welding may be employed to deposit the reaction material in the form of a reaction material deposit onto the steel workpiece prior to assembling the steel and aluminum workpieces in a workpiece stack-up.

An aluminum wire body, in which an aluminum or aluminum alloy electric wire and a metal to be joined are joined by solder, wherein the solder includes an oxide glass including vanadium and a conducting particle. Preferably, the conducting particle contained in the solder is 90% by volume or less and the oxide glass is 20% by volume to 90% by volume. Further preferably, the oxide glass includes 40% by mass or more of Ag.sub.2O in terms of oxides and the glass transition point is 180° C. or less.