Pyrophosphate copper plating used as grounding electroplate liquid for cyanogen-free copper plating

Abstract

The invention discloses a strike bath solution with pyrophosphate plating copper as the cyanide-free copper, which contains a make-up agent and rehydration salt; the make-up agent contains the following raw materials: potassium pyrophosphate, copper pyrophosphate, ammonium citrate, sorbol, sulfosalt, phenyl carboxylate, dextrin, alkyl thiourea and nitrogen heterocyclic; the rehydration salt is as supplementation of all raw materials in the make-up agent during the plating process; the invention does not contain harmful substances, such as cyanidum, heavey metal, etc and is in compliance with EU RoHS Directive (2002 / 95 / EC) with stable bath solution and wide cathode current density range, and the plating layer prepared by the invention is fine, even and in a semi-bright state; and the make-up is conducted with original solution, supplementation is conducted with single rehydration salt, which is convenient in operation and simple in management; the plating layer is well adhesive to the matrix, with good straggling capability and covering capability. The invention is applicable in pre-plating of iron materials, zinc alloys, aluminum alloys and copper alloys, as well as barrel plating and suspension plating, with the waste water easy to dispose, which will not bring the secondary pollution.

Description

technical field [0001] The invention relates to a copper plating solution, in particular to a pyrophosphate copper plating solution used as a primer electroplating solution for cyanide-free copper plating. Background technique [0002] In the cyanide copper plating solution, because NaCN has a strong complexing force for copper ions, the dispersing ability and covering ability are good, the plating layer is crystallized finely, the plating solution is alkaline, and has the ability to remove oil, so it can guarantee to obtain a good bonding force. The coating is widely used as the base coating on steel substrates, aluminum alloys, zinc alloy die castings and copper alloy electroplating Cu / Ni / Cr, and has unparalleled advantages. However, the current efficiency of cyanide copper plating is low (only about 63%), and it contains a large amount of CN - , is highly toxic, and will cause great damage to the health of on-site operators; at the same time, the exhaust gas and sewage d...

AI Technical Summary

Problems solved by technology

[0013] In addition to the above-mentioned processes, there are citrate copper plating, tartrate copper plating, triethanolamine copper plating, etc. Although each process has its advantages, it is also caused by its own limitations. For example, the preparation of the plating solution is cumbersome. Or it is difficult to realize industrial production because of the difficulty in maintenance of the plating solution, or the high requirements for the operator, or the high cost of the plating solution.