subject: Ways To Produce Copper Powder In Sulphate Acidic Copper Plating Process [print this page] Copper powder is generated from cuprous ion in copper plating solution. It will lead to the formation of pinhole phenomenon of rough copper plating, deburring and copper powder off. Whether is the copper plating roughness produced by cuprous ion? Adding 0.03 ~ 0.05ml / L of 30% hydrogen peroxide in the test plating, if it is caused by cuprous ion, the copper powder will emerge again in some time. It means that cuprous ion is easy to produce copper powder (FCu). At this point, the workers should check the way for producing copper powder.
The ways for producing copper powder: check out that whether there is a black film on phosphor copper anode surface. Phosphor copper anode surface no less black film or black film, the phosphor copper anode of phosphorus beyond the control of a copper ion, the formation of copper powder, causing rough copper plating. It needs to replace phosphor copper anode. Phosphor copper anode can not exceed the copper plating bath surface. Black film protection beyond the surface of the phosphor copper anode, when the phosphor copper anode titanium basket gradually decline, and soon, without the protection of the black film phosphor copper anode from falling into the copper plating bath to produce a copper ion, the formation of copper powder, resulting in rough copper plating;
In addition, without the protection of black film phosphor copper anode surface is easy to generate sulfuric acid cuprous crystallization, falling into the copper bath and quickly produce a copper ion, the formation of copper powder, causing rough copper plating. The need to control the amount of phosphor copper anode. Plating bath on the conductive rod or board can not have the adhesion to copper crystalline copper crystals on the conductive rod is a copper ion, falling into the bath, it will quickly produce a copper ion, the formation of copper powder, causing rough copper plating.
The chloride ion is too low, the chloride ion can not be fully combined with a copper ion in the process of the formation of divalent copper ions, the copper can not be fully a copper ion (cuprous chloride) converted to divalent copper ions (copper sulfate), the formation of metal powder resulting in rough copper plating; chloride ion reduction is mainly from the large anode area and cathode area. That a large bath trough and long-term or too many times to plating small area model and small-size panels. Small cathode required divalent copper ions is also small, and relatively high deposition of cuprous chloride in the anode in the anode, and come off easily and precipitate or continuous filtration to remove a result of reduced chloride ion in the solution.
When the chloride ion is too high, it will form excessive amounts of cuprous chloride. The excessive cuprous chloride ion will produce a disproportionation reaction. Thus it will form the copper powder and cause rough copper plating. Increasing of chloride ion content is from the cleaning water or adding water. Midpoint of the control of chloride ion is 55ppm. The control range is 40 ~ 65ppm. If it is lower than 35ppm, it is necessary to add chlorine ion. When chlorine ion is high to 75ppm, it is necessary to do the preparatory work to reduce the chloride ion.Source:http://www.mhcmp.com
