The invention discloses
nano copper powder,
electrode copper paste, a
buzzer and a preparation method of the
buzzer, and relates to the technical field of
metal material and
electronic component manufacturing. The surface of a
copper powder matrix is coated with an organic-inorganic composite layer, organic-inorganic combination is utilized, inorganic components react with the surface of the
copper powder to generate a layer of compact composite
passivation film, the protection performance is excellent, meanwhile, organic components form covalent bonds and coordinate bonds through complex reaction and
chemical adsorption, the covalent bonds and the coordinate bonds are alternated to form a chain
polymer, and the covalent bonds and the coordinate bonds are separated from the covalent bonds and the coordinate bonds. A plurality of
layers of protection films in parallel orientation are formed on the surface of copper, so that the surface of the copper is not subjected to oxidation-reduction reaction, the anti-oxidation effect is achieved, and the
conductivity of the copper is guaranteed. In addition, the organic-inorganic composite layer can efficiently inhibit copper oxidation and
electrochemical migration even at a high temperature, and the stability of the organic-inorganic composite layer is obviously superior to that of
silver paste in a humid and hot environment.