Compared with a copper ball, titanium anode has incomparable advantages because it belongs to completely different anode types. To sum up, its advantages are mainly reflected in the following points.
i. Stable electroplating uniformity
The electroplating uniformity advantage of titanium anode refers to that the use of insoluble anode can maintain stable electroplating uniformity for a long time, which is determined by the characteristics of insoluble anode . In the process of electroplating, in order to ensure the stability of electroplating uniformity, it is necessary to ensure that the electroplating conditions are controllable and stable. A very important point is to maintain the uniformity of discharge from positive to negative. The stability of discharge from positive to negative is largely determined by the relative size of the two.
In the PCB copper plating process, the soluble copper ball used will dissolve with the progress of electroplating, resulting in the reduction of anode size (mainly anode height) and the change of relative area. The uniformity of copper anode cannot be maintained for a long time. The insoluble anode is also called "size stable anode", which means that the anode size of the insoluble anode remains stable for a long service life.
At this time, it is only necessary to ensure that the coating on the surface of titanium anode does not fail during the service life, and still has the ability of discharge and electrocatalysis, so as to ensure the discharge stability from anode to cathode. Generally, after the insoluble anode is installed on the line, it is only necessary to adjust the electroplating uniformity for the first time (such as adjusting the size and position of the shielding plate), and a stable electroplating thickness distribution can be obtained for a long time, which can achieve "once and for all" in the whole anode life cycle.
ii. Higher productivity
Compared with a copper ball, the improvement of production efficiency brought by titanium anode is mainly reflected in the following two aspects:
On the one hand, titanium electrode can work at higher current density. Due to the passivation of phosphate film on the surface of the copper ball, the maximum working current density shall not exceed 2.5 ~ 3 ASD; The maximum current density that titanium electrode can withstand is dozens of times higher than that of the copper ball (for example, in the field of steel electroplating, the working current density of titanium electrode can reach more than 100 ASD). Therefore, through the support of equipment and the matching of corresponding electroplating conditions, the anode has the possibility to achieve higher equipment capacity and production efficiency.
On the other hand, titanium anode avoids the production interruption caused by regular addition and maintenance of copper ball process. When using it, the consumed copper balls must be supplemented at regular intervals. Before adding a new copper ball, it needs to be cleaned. It cannot be produced immediately after adding. It needs a certain time of electrolytic dragging cylinder operation to form a phosphating film on its surface. The copper ball used for a long time is close to the residue state, so it must be completely cleaned out of the titanium basket to avoid the problem of electroplating quality.
These inevitable maintenance operations make the copper plating equipment using copper balls not only unable to operate continuously for a long time, but also consume a lot of manpower. The copper oxide powder adding device using titanium anode to supplement copper ion is independent, there is no need to shut down to supplement copper oxide powder. At the same time, it is "maintenance free", that is, in principle, there is no need to clean during its life cycle. Therefore, using can theoretically achieve uninterrupted production, thus saving a lot of maintenance time and manpower investment.
