A kind of electroless palladium plating liquid, its preparation method and its use method and application

Abstract

The invention provides a chemical palladium plating solution, and a preparation method, an application method and applications thereof. The chemical palladium plating solution comprises palladium ions(0.5-5 g / L) and a reducing agent (1-20 g / L); wherein the palladium ions are provided by palladium tetramminosulfate. Palladium tetramminosulfate in provided chemical palladium plating solution is a solid soluble palladium salt; palladium exists in a tetra-amine palladium complex form; at a room temperature, palladium can be stably stored in a solid form, the storage and transportation are easy; moreover, compared with palladium sulfate or other palladium salts, palladium tetramminosulfate is very stable, and the problem of easy precipitation of palladium is solved.

Description

technical field [0001] The invention belongs to the technical field of surface treatment, and relates to an electroless palladium plating solution, its preparation method, its use method and application. Background technique [0002] In the electronic packaging industry, including surface treatment processes such as wafer-level packaging, IC substrates, PCBs, and FPCs, the chemical nickel-gold process proposed in the 1980s, the coating formed by gold has good oxidation resistance and electrical conductivity, nickel As a barrier layer to prevent the interdiffusion of copper and gold, but chemical nickel and gold often have quality problems such as missed plating, gold penetration, black nickel and white gold layer. [0003] In order to solve the above problems, the chemical nickel-palladium-gold surface treatment process is proposed, which is a further development of the chemical nickel-gold process. An electroless palladium layer is added between the chemical nickel plating ...

AI Technical Summary

Problems solved by technology

The prior art mainly uses water-soluble compounds such as palladium chloride, diammonium palladium chloride, tetraammonium palladium chloride, palladium sulfate as main palladium salts, and uses chlorine such as palladium chloride, diammonium palladium chloride, tetraammonium palladium chloride, etc. As the main salt, the chemical compound must be stored and transported in a liquid state, and production operations are not used.

In addition, Cl - The existence of the circuit board exposed in the environment will easily form a primary battery and cause electrochemical corrosion, and in the electronic packaging process, Cl - The existence of Pd may cause leakage; while palladium sulfate is used as the main salt, there are problems such as poor stability and easy precipitation of Pd.

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