The invention discloses composite
copper powder with micron
copper particles densely coated with
nano copper particles, a synthesis method of the composite
copper powder, copper paste and preparation and application of the copper paste. The composite copper
powder with the micron copper particles compactly coated with the
nano copper particles is composed of the micron copper particles with the
diameter being 1-2 microns and the
nano copper particles with the
diameter being 5-20 nm. Wherein the micron copper particles are completely and tightly wrapped by the nano copper particles, and the characteristics of micro-nano cross-scale particle size bimodal distribution and compact stacking are shown; nano copper particles grow on the surfaces of pretreated micron copper particles in an oriented mode through a
chemical reduction method to synthesize the micro-nano composite copper powder, the copper powder, the surfactant and the
organic solvent are mixed and stirred to prepare the copper paste, the obtained copper paste remarkably inhibits oxidation when the copper powder is sintered in air, the excellent
sintering performance is shown, and the copper paste can be used for preparing the copper paste. Rapid
sintering interconnection of a copper paste joint under a low-temperature condition is promoted, and the method is suitable for low-temperature rapid packaging and
assembly interconnection of high-power electronic components.