Analysis of Connectors Uneven Electroplating
Blog | Jan 25,2022
Uniformity of Cathode Metal Coating Distribution
This is an important factor to determine the quality of the coating. In electroplating production, people always hope to get a uniform coating on the surface of the plated parts.
The function part of the jack contact in the connector is the inner surface of the jack. If the coating on the inner and outer surface of the plated parts can be uniformly distributed, the production cost can be reduced to the maximum.
But in fact, no matter what kind of plating solution is used, there is always the phenomenon of uneven coating thickness.
During electroplating, the amount of material precipitated at the cathode is proportional to the amount of electricity flowing through the electroplating solution (electrolyte solution).
From this point of view, the coating distribution of the surface part depends on the current distribution on the surface cathode. As a result, all factors that affect the current distribution on the cathode surface will affect the distribution of the coating on the cathode surface.
In addition, in the electroplating process, the reaction on the cathode is often not simple metal precipitation, but also accompanied by a chlorine reaction or other side reactions. It can be analyzed that the coating distribution is also affected by the coating properties.
In the daily production of contact gold plating, it is found that the uniformity of the coating distribution on the cathode is not only related to the properties of the solution, but also closely related to the shape of the plated part, the choice of the coating method, and the choice of the coating.
Connectors Uneven Electroplating——Current Density
Any plating solution has a range of current densities to obtain a good coating. When the current density exceeds the upper limit value of the process range in the electroplating process, coarse crystal particles are often formed. So the coating obtained under the operation of low current density is more delicate.
For rolling gold plating or vibrating gold plating, a good coating can be obtained when the mass concentration of gold inking gold plating solution is low (generally 2~6 g/L) and the current density is between 0.1 ~ 0.4 A/dm2.
However, when the upper current density is used, [Au(CN)2]- near the cathode will be lacking. It will result in an increased chlorine reaction on the cathode and the current efficiency will be reduced.
Therefore, the production time of electroplating with 0.2a /dm2 current density and electroplating with 0.1a /dm2 current density is not A simple multiple relationships.
In the low-rate plating processes of barrel and vibration plating, if higher current densities are used, the possibility of tipping increases. In vibratory electroplating, the tip effect is more pronounced because the electroplating tip is always facing the anode (the anode ring outside the shaker) throughout the electroplating process.
Plated edges or pins, and socket tips have a thinner coating on the thick and low ends, resulting in an uneven distribution of coating thickness on the surface of the part.
In applications with low-speed gold plating processes, elongated pinhole contacts generally operate at the lower end of the current density range.
Zhejiang Lianhe electronic Co., Ltd. specializes in the production of all kinds of wire to board connector, board to board connector, wire to wire connector, etc., all kinds of electronic connectors welcome new and old customers to order. Contact us at [email protected]
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