A metal preparation is provided which contains (A) 40 to <80% by weight of at least one metal in the form of particles having a coating that contains at least one organic compound, and (B) >20 to 50 by weight organic solvent.

A surface treating composition for copper or a copper alloy comprising an imidazole compound and means for using the composition in the soldering of electronic parts to printed wiring boards are disclosed.

A solder paste having improved self alignment for soldering is provided. The solder paste includes a solder powder; a composite epoxy resin containing a first epoxy resin that is solid at 25 C., and a second epoxy resin that is liquid at 25 C.; and a curing agent, wherein the first epoxy resin has a softening point that is at least 10 C. lower than the melting point of the solder powder, and is contained in a range of 10 weight parts to 75 weight parts with respect to the total 100 weight parts of the composite epoxy resin.

Flux formulations that remain pliable and tack-free after deposition are disclosed. In certain examples, the flux comprises a first component and an effective amount of a second component to provide a pliable flux after deposition. The flux may also include activators, plasticizers, surface active agents and other components.

A method of forming a stacked surface arrangement for semiconductor devices includes joining a first surface to a second surface with a solder bump, the solder bump including a substantially pure first metal; depositing nanoparticles of a second metal onto a surface of the solder bump; performing an annealing operation to form a film of the second metal on the surface of the solder bump; and performing a reflow or a second annealing operation to transform the solder bump from the substantially pure first metal to an alloy of the first metal and the second metal.

Flux formulations that remain pliable and tack-free after deposition are disclosed. In certain examples, the flux comprises a first component and an effective amount of a second component to provide a pliable flux after deposition. The flux may also include activators, plasticizers, surface active agents and other components.

Non-aqueous solder flux compositions are disclosed. In some aspects, the compositions comprise: (a) an alkylbenzene sulfonic acid or an acidic phosphate ester; and (b) an alkanolamide, an ethoxylated alkanolamide, an alkanolamine, or an ethoxylated amine. Methods of making solder flux compositions and methods of using the compositions as components of tacky solder fluxes are described. The solder flux compositions have excellent wettability, oxide removal capability, and rheological characteristics for high-speed, pick-and-place manufacturing processes and can be made from a simple combination of two components, thereby avoiding the need for solvents, polymeric thickeners, and other components of traditional tacky solder fluxes.