Method for synthesizing copper-silver alloy, method for forming conduction part, copper-silver alloy, and conduction part

A method for synthesizing a copper-silver alloy, comprising:

• an ink preparation step of mixing a copper salt particle, an amine-based solvent, and a silver salt particle, thereby preparing a copper-silver ink;
• a coating step of coating a member to be coated with the copper-silver ink to form a coated member;
• a crystal nucleus formation step of forming at least one of a crystal nucleus of copper having a crystal grain diameter of 0.2 μm or less and a crystal nucleus of silver having a crystal grain diameter of 0.2 μm or less from the copper-silver ink;
• and
• a crystal nucleus synthesis step of synthesizing the crystal nucleus of copper and the crystal nucleus of silver, wherein
• the crystal nucleus formation step contains a first-heating step where the coated member is heated at 70° ° C. to 300° C. for 1 minute to 300 minutes, and
• the crystal nucleus synthesis step contains a second-heating step where the crystal nucleus of copper and the crystal nucleus of silver are irradiated with pulsed light having an energy density of 0.5 J/cm2 to 5.0 J/cm2 for an irradiation time of 1 s or less so that the copper-silver alloy is synthesized.