Preparation method of vapor chamber upper cover plate and vapor chamber

The invention provides a preparation method of a vapor chamber upper cover plate, the vapor chamber upper cover plate, and a vapor chamber. The preparation method of the vapor chamber upper cover plate comprises the steps that the vapor chamber upper cover plate is manufactured; electrochemical deposition is conducted on the upper cover plate, and a capillary structure layer of a porous structureis formed on the inner wall of the upper cover plate in a deposition mode, specifically, the upper cover plate serves as a cathode of electrochemical deposition, the capillary structure layer is madeof copper, and an electrolyte for electrochemical deposition per liter comprises 30-80 g of copper sulfate, 150-200 g of sulfuric acid, sulfate with sulfate radical concentration of 0.04-0.55 mol/L, and 11.5-46.5 mL of a first additive; and heat treatment is conducted on the capillary structure layer to obtain the vapor chamber upper cover plate with the capillary structure layer. The capillary structure is constructed on