Solder paste consisting of 85 to 92% by weight of a tin-based solder and 8 to 15% by weight of a flux, wherein the flux comprises i) 30 to 50% by weight, based on its total weight, of a combination of at least two optionally modified natural resins, ii) 5 to 20% by weight, based on its total weight, of at least one low-molecular carboxylic acid; and iii) 0.4 to 10% by weight, based on its total weight, of at least one amine, and wherein the combination of the optionally modified natural resins has an integral molecular weight distribution of 45 to 70% by area in the molecular weight range of 150 to 550 and of 30 to 55% by area in the molecular weight range of >550 to 10,000 in the combined GPC.

This paste composition includes silver particles (A), a thermosetting resin (B), a curing agent (C), and a solvent (D). A shrinkage rate after curing of the paste composition is 15% or less.

A method for step-soldering includes applying a first solder alloy having a melting point in a temperature range from 160 to 210° C. to a jointed portion of a first electronic component and a substrate, and heating them in the temperature range from 160 to 210° C., and applying a second solder alloy having the melting point in a temperature range lower than 160° C. to a joint portion of a second electronic component and the substrate, and heating them in the temperature range lower than 160° C. The first solder alloy consists of 13-22 mass % of In, 0.5-2.8 mass % of Ag, 0.5-5.0 mass % of Bi, 0.002-0.05 mass % of Ni and a balance Sn.

A field device for processing and automation technology includes a first and a second component that can each be mechanically connected at a joining surface by means of a joining point. Two metal surface layers are each applied at least to the joining surface of the first component and the joining surface of the second component. The metal of the surface layers is different from the metal of the first and/or the metal of the second component. A joining material is applied between the respective joining surfaces of the two components, wherein the joining material includes particles at least partially consisting of a metal that corresponds with the metal of the surface layers The joining of the two components occurs at a joining temperature below 300° C.

A component mounting method includes an application step of applying a specific solder paste including Sn and a metal other than Sn to a board; a disposition step of positioning and disposing an upper surface reference type component having a positioning reference on an upper surface with respect to one or more reference points on the board; and a reflow step of reflow-soldering the component by heating the board, in which in the specific solder paste, at least a part of the Sn is melted, and molten Sn and the metal other than Sn form an intermetallic compound in the reflow step, thereby fixing the upper surface reference type component to the board.

The invention relates to a method for producing a metal-ceramic substrate and to a furnace suitable for carrying out the method. With the method, a metal-ceramic substrate with increased thermal and current conductivity can be obtained. The method comprises the steps of providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, the solder material comprising a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal, and heating the stack, the stack passing through a heating zone for heating.

The present invention relates to a method for producing a metal-ceramic substrate. The method has the following steps: providing a stack containing a ceramic body, a metal foil, and a solder material in contact with the ceramic body and the metal foil, wherein the solder material has: a metal having a melting point of at least 700° C., a metal having a melting point of less than 700° C., and an active metal; and heating the stack, wherein at least one of the following conditions is satisfied: the high temperature heating duration is no more than 60 min; the peak temperature heating duration is no more than 30 min; the heating duration is no more than 60 min.

A magnetic-field melting solder that melts by the action of an AC magnetic field is provided. The magnetic-field melting solder includes solder material; and magnetic material composing of ferrite or Ni, a proportion of the magnetic material to the entire magnetic-field melting solder being 0.005% to 5% by weight. A joining method using the magnetic-field melting solder includes providing the magnetic-field melting solder between an electrode on a substrate and an electrode of an electronic component, and joining together the electrode on the substrate and the electrode of the electronic component by generating an AC magnetic field around the substrate and thereby melting the magnetic-field melting solder.

A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 μm and less than or equal to 0.8 μm, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 μm and less than or equal to 50 μm, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300° C., and a content of the solvent having a boiling point of higher than or equal to 300° C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.

A solder paste includes a first solder alloy powder in an amount ranging from 30% to 95% by weight. The first solder alloy powder includes a first solder alloy with a solidus temperature of 200° C. to 260° C. The first solder alloy includes an Sn—Cu alloy or an Sn—Cu—Ag alloy. The solder paste further includes a second solder alloy powder in an amount ranging from 5% to 70% by weight, and a solder flux. The second solder alloy powder includes a second solder alloy with a solidus temperature below 250° C. The solder paste has a variable melting point. In multiple reflow soldering, a remelting of the solder paste is inhibited under different temperature conditions so that no functional failure occurs during assembly and/or packaging of PCBs or electronic devices due to melting of solder.