▎ 摘　　要

NOVELTY - A epoxy silver paste comprises graphene, conductive metal powder, epoxy resin, epoxy thinner, dynamic curing agent , curing accelerator, self-healing accelerator and coupling agent. The epoxy silver paste is prepared by (1) preparing graphene oxide, (2) dispersing graphene oxide in deionized water and ultrasonically reacting to obtain graphene oxide/water dispersion, adding amino acid and amide reaction catalyst and heating with stirring for 5 hours, adding hydrazine hydrate, stirring, washing and drying to obtain graphene functionalized by carboxylic acid group, (3) mixing epoxy resin and epoxy diluent, adding coupling agent to mixture of epoxy resin and epoxy diluent, and mixing at room temperature, (4) adding carboxylic acid-functionalized graphene and ultrasonically dispersing, (5) adding dynamic curing agent, curing accelerator and self-repairing accelerator to mixture and mixing, and adding conductive metal powder, mixing and removing bubbles by vacuum stirring. USE - Self-repairing epoxy silver paste for use in high power semiconductor package and light emitting diode. ADVANTAGE - The self-repairing epoxy silver paste has increased electric and thermal conductivity and prolonged service life. DETAILED DESCRIPTION - The self-repairing epoxy silver paste comprises 0-20 wt.% graphene, 50-80 wt.% conductive metal powder, 1-10 wt.% epoxy resin, 1-5 wt.% epoxy thinner, 5-15 wt.% dynamic curing agent , 0.1-1 wt.% curing accelerator, 0.1-1 wt.% self-healing accelerator and 0.5-2 wt.% coupling agent. The step (1) involves preparing graphene oxide by adding 1-10 ml concentrated sulfuric acid to three-necked flask, adding 1-100 g graphite, 1-10 g sodium nitrate and 1-20 g potassium permanganate under stirring, heating at 35-100 degrees C for 1 hour, dripping deionized water, heating at 80 degrees C for 45-90 minutes, after reaction is over, diluting product with 100-500 ml deionized water, adding hydrogen peroxide to terminate the reaction, washing the product with dilute hydrochloric acid to remove metal ions, washing with deionized water until neutral, air-drying or freeze-dying. In step (2), the content of amino acid is 1-10 wt.% graphene oxide, and ultrasonically reacting for 0.5-1 hours, and stirring at 50-80 degrees C for 10-24 hours. The step (3) involves mixing epoxy resin and epoxy diluent at room temperature for 3-30 minutes. The step (4) involves ultrasonically dispersing for 1-5 hours. The step (5) involves vacuum stirring at 20-40 degrees C.