A brazing paste contain 80% by mass or more and 95% by mass or less of a brazing material; and 5% by mass or more and 20% by mass or less of a binder. The binder contains a solid solvent containing two or more hydroxyl groups and having 5 to 7 carbon atoms, and a liquid solvent.

The present invention uses a flux containing a rosin, a solvent, a thixo agent, and an activator. The thixo agent contains a polyamide and a compound represented by general formula (1). The polyamide is a condensate between an amine and at least one selected from aliphatic carboxylic acids and hydroxy group-containing aliphatic carboxylic acids, and has an endothermic peak at a temperature of 120-200° C. In the general formula, R.sup.11 represents a hydrocarbon group having 11-30 carbon atoms. R.sup.0a represents a hydrogen atom or a hydrocarbon group having 12-31 carbon atoms. R.sup.0b represents an n-valent hydrocarbon group having 4-12 carbon atoms. R.sup.21 represents an alkylene group having 2-6 carbon atoms. R.sup.0c represents a single bond or an alkylene group having 2-6 carbon atoms. n represents 1 or 2. When n represents 1, m represents an integer of 1-3. When n represents 2, m represents 1.

##STR00001##

Invention compositions are a replacement for high melting temperature solder pastes and preforms in high operating temperature and step-soldering applications. In the use of the invention, a mixture of metallic powders reacts below 350 degrees C. to form a dense metallic joint that does not remelt at the original process temperature.

Provided is a metal paste for joints, containing: metal particles; and linear or branched monovalent aliphatic alcohol having 1 to 20 carbon atoms, in which the metal particles include sub-micro copper particles having a volume average particle diameter of 0.12 μm to 0.8 μM.

A solder alloy is provided which can withstand the severe characteristics of a temperature cycle between a low temperature of −40° C. and a high temperature of 125° C., withstand an external force applied due to, for example, riding on a curb or collision with a vehicle ahead for a long period of time, and can suppress change in viscosity of a solder paste over time. In addition, a solder paste, a solder ball, and a solder preform in which the solder alloy is used; a solder joint formed through the use thereof; and an on-board electronic circuit, an ECU electronic circuit, an on-board electronic circuit device, and an ECU electronic circuit device which include this solder joint are provided. The solder alloy contains, by mass %, 1% to 4% of Ag, 0.5% to 1.0% of Cu, 1.5% to 5.5% of Bi, 1.0% to 5.3% of Sb (or greater than 5.5% and less than or equal to 7.0% of Bi and 2.0% to 5.3% of Sb), 0.01% to 0.2% of Ni, 0.0040% to 0.0250% of As, and a balance of Sn.

An iodine-containing cyclic compound including no carboxy group and including one ring skeleton or a plurality of ring skeletons forming a fused ring in one molecule, is provided. The ring of the ring skeleton includes only a carbon atom, or a carbon atom, and a nitrogen atom and/or an oxygen atom, and an iodine atom is bonded to at least one of the atoms constituting the ring of the ring skeleton.

A thermoset component for joining with a thermoplastic component according to an exemplary embodiment of this disclosure, among other possible things includes a thermoset material, a weldable surface on the thermoset material, and a thermal barrier. The weldable surface includes a thermoplastic material. A hybrid polymeric component and a method of making a hybrid polymeric component are also disclosed.

A flux which imparts thixotropy, and which exhibits excellent printability, printing sagging-inhibiting ability, and heating sagging-inhibiting ability; and a solder paste which uses said flux. This flux includes a thixotropic agent, a rosin, an organic acid, and a solvent. The thixotropic agent includes a cyclic amide compound obtained by polycondensing a dicarboxylic acid and/or a tricarboxylic acid, and a diamine and/or a triamine into a cyclic shape; and an acyclic amide compound which is obtained by polycondensing a monocarboxylic acid, a dicarboxylic acid and/or a tricarboxylic acid into an acyclic shape. The flux includes at least 0.1 wt % but not more than 8.0 wt % of the cyclic amide compound, and at least 0.5 wt % but not more than 8.0 wt % of the acyclic amide compound. The total amount of the cyclic amide compound and the acyclic amide compound is at least 1.5 wt % but not more than 10.0 wt %.

A solder alloy comprising: from 40 to 65 wt. % bismuth; from I to IO wt. % indium; at least one of: from 0.1 to 5 wt. % gallium, from 0.1 to 5 wt. % zinc, from 0.1 to 2 wt. % copper, from 0.01 to 0.1 wt. % cobalt, from 0.1 to 2 wt. % silver, from 0.005 to 0.05 wt. % titanium, and from 0.01 to 1 wt. % nickel; optionally up to 1 wt. % of one or more of: vanadium, rare earth metals, neodymium, chromium, iron, aluminium, phosphorus, gold, tellurium, selenium, calcium, vanadium, molybdenum, platinum, magnesium, silicon, and manganese; and the balance tin together with any unavoidable impurities.

Provided are flux for resin flux cored solder, flux for flux-coated solder, resin flux cored solder using the flux for resin flux cored solder, flux-coated solder using the flux for flux-coated solder, and a soldering method, which have low residue and are excellent in processability. The flux for resin flux cored solder or flux-coated solder contains a solid solvent in an amount of 70 wt % or more and 99.5 wt % or less, and an activator in an amount of 0.5 wt % or more and 30 wt % or less.