Titanium anode (MMO) is made of precious metal strontium salt coated on titanium substrate and sintered at high temperature. It is widely used in electroplating (such as electroplating of copper in the circuit board industry, electroplating of gold, gold plating) and electrolysis. The preparation and application of the electrode has been quite mature, and it has been 40 years old. Compared with the traditional platinized electrode in the alkaline copper process, the titanium anode has the advantages of platinized electrode:
1. Technical characteristics
High current and high efficiency, excellent antibacterial corrosion performance; long electrode life; can run current density with higher current density: “10000A/M2 is an oxygen evolution type anode based on industrial pure titanium
2, high catalytic activity
It is well known that the platinized electrode is a high peroxygen potential (1.563V, relative to mercuric sulfate) electrode, while the MMO anode is a low oxygen evolution peroxidation (1.385V relative to mercuric sulfate) electrode in the anode oxygen evolution zone. It is easier to analyze oxygen. Therefore, when electrolysis, the trough village is also relatively low, which saves energy. This phenomenon has been evident in the copper foil post-treatment of alkaline copper-plated walls.
3. Pollution-free MMO
The anodic coating is a ceramic oxide of noble metal cerium, which is a relatively stable oxide, hardly soluble in any acid or alkali, and the oxide coating is about 20-40 μm, and the amount of overall coating oxide is less. . Therefore, the MMO anode does not pollute the plating solution, which is basically the same as the platinized electrode.
The same service life has been maintained for the platinized electrode (coating thickness 3.5mm), the price of the MMO anode is about 80% of the platinized electrode, and the MMO electrode has better electrochemical stability in the alkaline electroplating copper electrolyte. It has excellent electrolysis activity and durability. From the analysis of the cost of the company’s MMO anode and PT electrode, it is obvious that the 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 platinized titanium insoluble anodes is prohibited. The chloride in the 9 sulfuric acid electrolyte is present in this current environment. Peel off the platinum layer). However, the use of dimensionally stable anodes avoids this phenomenon and allows the insoluble anode technology to successfully achieve performance advantages in such applications.
6. The anode is kept to a minimum. There is no need to stop production for a cleaning and replenishing of the anode, replacement of the anode bag and re-plating of the anode (increased productivity, reduced labor costs);
7. The life of the insoluble anode depends on the type, working current density and contact with various plating chemicals;
Positive direction pulsation (PPR) plating anode
As the price of metal raw materials continues to rise, copper ions are easily concentrated in the edge portion of the pores (the high current density region), and the central portion of the pores (ie, the low current density region) is deposited at a relatively slower rate. . This results in a very uneven distribution of copper: the behavior is called “dog bone”. At a moderate current density, dog bones can occur, and at lower current densities, cracking occurs, and operation at higher current densities will occur. There is a burning phenomenon, which is undoubtedly a heavy impact on the electroplated circuit board.
Reverse pulse plating anodes are also born, because the reaction of copper in printed circuit boards requires the use of pulse period reversal (PPR) technology. We know that the use of platinized titanium insoluble anodes is used in sulfuric acid electrolytes, where chlorides are present. In a current environment, the platinum layer will peel off after a period of time.
Electroplating anodes with positive and negative pulses have the following characteristics:
1. The geometry of the anode remains the same, which optimizes the current distribution.
2. Less anode maintenance. There is no need to stop the production line to clean and replenish the anode, and replacement of the anode bag increases productivity and reduces labor costs.
3, to solve the problem of uniform coating of deep hole plating: high current efficiency, can withstand 1000A / M2 current density.
4. There is no pollution to the plating medium.
The positive inversion pulse plating anode is an oxygen evolution type electrode, which is based on industrial pure titanium (TA2). Electrical anode life and excellent corrosion resistance.