The electroplating of the connector considers the electroplating point of view, silver plating is the preferred process, but due to the high cost of silver and the poor color-resistance during the exterior mounting, the external connectors, especially the N-type connectors, are often used. Ternary alloy silver plating. The ternary alloy coating is composed of three kinds of copper, tin and zinc metal elements, the ratio of the three components in the coating is 65% to 70% copper, 15% to 20% tin, 10% to 15% zinc, but in the bath The content of each component can not be matched according to the content of the plating layer, but should be designed according to the amount of each coating component that can be reduced on the cathode to a suitable plating ratio. The basic composition of a common plating ternary alloy plating solution is as follows:
In production practice, ternary alloy plating is usually added with some commercial additives to obtain brighter and finer plating, but the plating can only have a brightening effect on the surface of the substrate when it is thinner. The finish and the brightness of the bottom coating also have certain requirements, ie, the bottom plating must have a high brightness to ensure the brightness of the ternary alloy coating. If the ternary alloy plating is thickly plated, it is difficult to obtain a full bright plating.