The invention provides a preparation method of silver-coated
copper powder, and belongs to the technical field of conductive
silver paste. The method comprises the following steps: S1, preparing a base solution containing
copper powder: uniformly mixing the
copper powder, a complexing agent and water to obtain the base solution; s2, a copper powder
oxide layer is removed, specifically, the base solution is stirred, and the copper powder
oxide layer is removed in the process of stirring the base solution; s3, silver-coated copper powder is prepared, specifically, a silver salt
aqueous solution is added into the base solution, and stirring continues; after the reaction is finished, washing and
drying to obtain silver-coated copper powder; the
mass of silver ions in the silver salt
aqueous solution is 1%-90% of the
mass of the copper powder. According to the method, operation is simpler,
coating is more uniform, the prepared silver-coated copper powder is lower in resistivity, the independent copper powder deoxidation step and the subsequent copper powder separation and washing step can be omitted, the copper powder deoxidation process is fused into the material mixing process, and the copper powder is prevented from being oxidized again in the separation and washing steps.