A kind of tin electroplating liquid and its preparation method and application

Abstract

The invention provides a tin electroplating solution and its preparation method and application. The tin electroplating solution comprises the following components in terms of mass concentration: stannous sulfate 10-50g / L, sulfuric acid 50-200g / L, wetting agent 0.05-5g / L, antioxidant 0.01-2g / L and grain refinement agent 0.01-2g / L; the solvent of the tin electroplating solution is water; the crystal refiner is a flavonoid compound. The tin electroplating solution of the present invention adopts stannous sulfate as the main salt, sulfuric acid is used as electrolyte to increase conductivity, and wetting agent, antioxidant and grain refiner are added, and each component cooperates with each other to play a synergistic effect, thereby in In the case of the same coating thickness, the production efficiency is greatly improved, and the tin source is saved; at the same time, the density of the tin coating can be improved, so that the tin coating has better alkaline corrosion resistance.

Description

technical field [0001] The invention belongs to the technical field of electrochemical deposition of metals, in particular to a tin electroplating solution and its preparation method and application. Background technique [0002] Tin is a non-toxic white metal with strong oxidation resistance and sulfide corrosion resistance, good chemical stability, and excellent solderability and electrical conductivity. Utilizing the good corrosion resistance of tin in the printed circuit board manufacturing process, it can protect the required copper lines in the alkaline copper chloride etching solution. At present, a large number of electroplating additive research work is mainly based on ordinary electroplating, which is difficult for electroplating with wide current density. Especially for electroplating pure tin, a large amount of air will be involved, which will not only cause the oxidation of divalent tin, but also easily increase the foam of the plating solution, affecting the w...

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Problems solved by technology

The coating prepared by the electroplating solution has a high content of organic matter, and the coating is brittle and cannot meet the needs of electronic devices for the flexibility of the coating. At the same time, the positioning effect of the coating is not good. Copper Leakage

[0004] CN104060308A discloses a pure tin electroplating solution for reducing copper exposure and its application. The acidic plating solution adopts a mixed solution of methanesulfonic acid and sulfuric acid, the tin salt adopts a mixed solution of soluble divalent tin salt and hydrogen peroxide, and adds Antioxidants, auxiliary agents, brighteners, wetting agents, surfactants and other components are added. When the plating process of this electroplating solution reaches the same coating thickness, it takes a long time, the content of additives is high, and the crystals are not refined enough, resulting in The density of the tin coating is poor

[0005] CN105648483A discloses a high-speed tin plating solution and a preparation method thereof, the main components of the tin plating solution are methanesulfonic acid, stannous methanesulfonate, antioxidant, grain refiner and surfactant, the tin Although the solution can increase the plating speed to a certain extent, the organic matter content in the coating prepared by the electroplating solution is high, the coating is brittle, and the coating is poor in compactness.

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