Manufacturing method of chemical nickel palladium gold plating plated with thick palladium

Abstract

The invention relates to the technical field of chemical nickel palladium gold platings, and discloses a manufacturing method of a chemical nickel palladium gold plating plated with thick palladium. The method is used for forming a nickel palladium gold plating on a surface of a circuit board, and comprises the following steps: 1) acidic oil removing; 2) micro-etching; 3) acid washing; 4) acid pre-pickling; 5) palladium activation; 6) acid post-pickling; 7) chemical nickel plating; 8) chemical plating of thick palladium, that is, chemical deposition of a palladium layer on a nickel layer of a circuit board by using organic acid and palladous sulfate; 9) chemical gold dipping. The palladium layer is formed on the nickel layer by using organic acid and palladous sulfate. The palladium layer is a palladium-storing system, and has a high thickness, so only a thin gold layer is needed to be formed on the palladium layer. Therefore, the production cost of the plating is reduced, the use of gold salt with severe toxicity is reduced, and the safety is greatly improved; figure 2 shows the surface nanometer morphology of the palladium layer; the palladium layer has low hardness and internal stress, and has excellent wetting performance; therefore, the gold wire bonding performance and the tin soldering performance of the plating are excellent.

Description

technical field [0001] The invention relates to the technical field of chemical nickel-palladium-gold plating, in particular to a method for preparing a thick palladium-plated chemical nickel-palladium-gold plating. Background technique [0002] With the gradual development of electronic products in the direction of high performance, multi-function, high reliability, light and thin, portable and low cost, in order to meet the needs of the market and technology, not only the PCB products must be moved to higher density product types, but also the electronic The packaging industry must move towards high-density packaging such as IC packaging or system packaging, which requires a coating that can meet a variety of packaging processes, so ENEPIG, a surface treatment process with a reputation of "universal" coating It came into being. [0003] The electroless nickel palladium gold process is divided into three steps, namely electroless nickel plating, electroless palladium plati...

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Problems solved by technology

[0005] The object of the present invention is to provide the preparation method of the electroless nickel-palladium-gold coating of thick-plated palladium, aim to solve the thicker gold layer thickness of the chemical nickel-palladium-gold coating in the prior art, cause production cost higher, safety reduces, coating layer The problem of poor performance of gold wire and poor soldering performance

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