Titanium anode (MMO) is made of precious metal iridium salt coated on titanium substrate by high temperature sintering, widely used in electroplating (circuit board industry deep hole high requirement electroplating copper, electroplating), electrolysis and other wet metallurgy industry. The preparation and application of the electrode has been quite mature, with a history of 40 years. Compared with the traditional platinum plating electrode in alkaline copper process, titanium anode has incomparable advantages:
1. Technical features
High efficiency of current, excellent anti-corrosion property; Long service life of electrode; "10000A/M2" is an oxygen evolution anode based on industrial pure titanium
2. High catalytic activity
It is well known that the platinum-plated electrode is an electrode with a high over-oxygen potential (1.563V, relative to mercurous sulfate), while the MMO anode is an electrode with a low oxygen evolution potential (1.385V, relative to mercurous sulfate), which is easier to develop oxygen in the anode oxygen evolution area. Therefore, electrolysis, trough village is also relatively low, more energy saving. This phenomenon in copper foil after treatment of alkaline copper plating wall, has been clearly reflected.
3. Pollution-free MMO
Anodic coating is precious metal iridium ceramic oxide, the oxide is a fairly stable oxide, almost insoluble in any acid base, and the oxide coating of about 20-40 m, the overall coating of the oxide amount is small. Therefore, the MMO anode does not contaminate the bath, as does the platinum plated electrode.
4. High cost performance
The same service life has been maintained for the platinum-plated electrode (coating thickness: 3.5mm). The price of the MMO anode is about 80% of that of the platinum-plated electrode. The MMO electrode has better electrochemical stability in alkaline copper electroplating electrolyte, as well as excellent electrolytic activity and durability. From the analysis of the cost of MMO anode and PT electrode, it is obvious that MMO electrode is economical.
5. Since the application of copper in printed circuits requires the use of pulse period reversal (PPR), we know that the use of platinum titanium insoluble anode is prohibited. 9. However, this can be avoided by using a dimension-stable anode, and insoluble anode technology can be used successfully to achieve performance advantages in such applications.
6. Minimum anode maintenance. There is no need to stop production to clean and replenish anode, replace anode bag and recoat anode (higher productivity, lower labor cost);
7. The life of the insoluble anode depends on the type, working current density and contact with various electroplating chemicals;
Positive direction pulsation (PPR) plating anode
Because of the rising cost of raw materials, copper ions tend to deposit rapidly at the edge of the hole (the area with high current density), and much more slowly at the center of the hole (the area with low current density). This results in a very uneven distribution of copper deposition: the behavior is called "dog-bone". Operating at moderate current density results in dog-bone shape, operating at low current density results in tube cracking, and operating at high current density results in ignition. Electroplate circuit board is a heavy impact.
Since the reaction of copper in printed circuit boards requires the use of pulse period reversal (PPR) technology, we know that platinum and titanium insoluble anodes are used in sulfuric acid electrolyte. Chloride exists in this current environment, which will peel off the platinum layer after a period of time.
The positive and negative pulse electroplating anode has the following characteristics:
1. The geometric dimensions of the anode remain unchanged, thus optimizing the current distribution.
2. Less maintenance of anode. No need to stop production line to clean and replenish anode, replace anode bag to improve productivity and reduce labor cost.
3. Solve the problem of uniform coating of deep hole electroplating: high current efficiency, can withstand 1000A/ M2 current density.
4, the plating medium will not produce pollution.
The positive and negative pulse electroplating anode is an oxygen evolution electrode based on industrial pure titanium (TA2). The service life and excellent corrosion resistance of electric anode.