Double-tank method for continuously plating thick gold with cyanide-free chemical gold plating solutions

Abstract

The invention relates to a cyanide-free chemical method for plating thick gold, particularly a double-tank method for continuously plating thick gold with cyanide-free chemical gold plating solutions. The method comprises the following steps: 1) immersing a substrate in a first cyanide-free chemical gold plating solution, and carrying out replacement gold plating to deposit a thin gold layer, wherein the thickness of the obtained gold film is 0.02-0.08 mu m; and 2) transferring the product obtained in the step 1) into a second cyanide-free chemical gold plating solution, and carrying out reduction-type chemical gold plating to deposit a thick gold layer, wherein the thickness of the obtained gold film is up to 0.3-2 mu m. The gold plating has the advantages of favorable binding force with the substrate, golden appearance and fine and compact crystals. The purity of the gold layer is 100%; and when the gold layer is subjected to welding, no black tray phenomenon is generated. The cyanide-free chemical gold plating solutions have the stability for practical application. The invention can solve the problem of thin gold layer in the replacement gold plating technique, and the problems of high pollution tendency, cyanide containing and the like in the plating solution in the reduction-type chemical gold plating technique.

Description

technical field [0001] The invention relates to a method for cyanide-free chemical thick gold plating, in particular to a double-slot continuous thick gold plating method using a cyanide-free chemical gold plating solution. Background technique [0002] The appearance of the gold coating is golden yellow, with excellent properties such as corrosion resistance, low contact resistance, good solderability, and thermocompression bonding. It can be used as a decorative coating, a protective coating and a functional coating, especially suitable and widely used in the electronics industry Such as surface finishing of printed circuit boards, flexible circuit boards, ceramic integrated circuit packaging, microchip processing, VLSI and advanced equipment devices. Electroless gold plating technology is widely used in partial gold plating and surface gold plating of non-conductive materials such as ceramics, plastics, glass, and silicon semiconductors. [0003] Electroless gold plating...

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to provide a kind of double tank continuous using cyanide-free chemical gold plating solution which can overcome problems such as thin gold layer in the displacement gold plating process, plating solution easily polluted in reduction type chemical gold plating process, and chemical gold plating solution containing cyanide. thick gold plating method

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