Abstract: A connection structure including: a first circuit member having a plurality of first electrodes; a second circuit member having a plurality of second electrodes; and an intermediate layer having a plurality of bonding portions electrically connecting the first electrodes and the second electrodes, in which at least one of the first electrode and the second electrode that are connected by the bonding portion is a gold electrode, and 90% or more of the plurality of bonding portions include a first region containing a tin-gold alloy and connecting the first electrode and the second electrode and a second region containing bismuth and being in contact with the first region.

Abstract: A method for producing solder particles, which includes: a preparation step wherein a base material that has a plurality of recesses and solder fine particles are prepared; an accommodation step wherein at least some of the solder fine particles are accommodated in the recesses; and a fusing step wherein the solder fine particles accommodated in the recesses are fused, thereby forming solder particles within the recesses. With respect to this method for producing solder particles, the average particle diameter of the solder particles is from 1 ?m to 30 ?m; and the C.V. value of the solder particles is 20% or less.

Abstract: A method for producing an anisotropic conductive film, which includes: a preparation step wherein a base material that has a plurality of recesses and solder fine particles are prepared; an accommodation step wherein at least some of the solder fine particles are accommodated in the recesses; a fusing step wherein the solder fine particles accommodated in the recesses are fused, thereby forming solder particles within the recesses; a transfer step wherein an insulating resin material is brought into contact with the recess opening side of the base material that includes the solder particles in the recesses, thereby obtaining a first resin layer on which the solder particles have been transferred; and a layering step wherein a second resin layer that is configured from an insulating resin material is formed on the surface of the first resin layer, on which the solder particles have been transferred, thereby obtaining an anisotropic conductive film.

Abstract: The present invention relates to solder particles, each of which partially has a flat portion in the surface. By using these solder particles, electrodes facing each other are able to be appropriately connected, thereby achieving an anisotropic conductive material that exhibits excellent conduction reliability and excellent insulation reliability.