With the advancement of the times and the increasing requirements for thinner and lighter electronic products, circuit board manufacturing processes are also constantly improving. In recent years, titanium anodes have gradually been recognized and understood by more people in the PCB copper plating process. Compared with traditional phosphor copper balls, which continue to dissolve during use, titanium anodes remain stable in shape and do not undergo dissolution reactions during use, so they are called insoluble anodes and are also called dimensionally stable anodes. With the improvement of product requirements, the requirements of PCB copper plating process are also increasing. Titanium anodes are gradually showing advantages over phosphor bronze balls, and are gradually replacing the market share of phosphor bronze balls. This article will give a general introduction to titanium anodes, and combine our decades of experience in the development and manufacturing of titanium anodes to share some knowledge and experience in the design and use of titanium anodes, so that more people can understand titanium anodes. Anode has further in-depth understanding.
1. Introduction to titanium anode
1.1 Definition of titanium anode
1.2 Development history of titanium anodes
Speaking of the history of titanium anodes, its birth is inseparable from the Dutchman Henry Beer (H.B. Beer). Dating back to 1957, Beer took the lead in inventing the technology of electroplating platinum on titanium metal, applied for a patent, and founded MAGNETOChemie (the predecessor of MAGNETO Chemie). In 1967, Beer invented a method of forming a metal oxide film on titanium metal. One specific implementation example used ruthenium oxide as an anode for salt water electrolysis, which promoted great changes in the chlor-alkali industry. This coating is still widely used in various electrochemical chlorine evolution reactions today. With the in-depth research on various platinum group metals and their oxides, in the 1970s, iridium-tantalum mixed metal oxide coatings were successfully developed and gradually began to be used in electrochemical oxygen evolution reactions. Today, titanium anodes rely on their superior performance and are widely used in many electrochemical fields, including chemical industry (chlor-alkali industry), electrolytic organic synthesis, electroplating, cathodic protection, industrial and civil electrolytic chlorine production and disinfection, and other application fields.
Since the 1990s, titanium anodes have been used in PCB copper plating processes, and were further developed and improved in the first decade of this century. In the past 10 years, with the improvement of PCB process capability requirements, titanium anodes have gradually begun to replace soluble anodes-phosphorus copper balls with their unique advantages. Depending on the electroplating requirements, titanium anodes can be used not only for DC plating, but also for reverse pulse plating. In the future, as the copper plating process requirements further increase, titanium anodes will continue to be researched and developed to adapt to new electroplating conditions.
2. Reaksiya printsipi of titanium anod
The anode reaction process of the soluble anode is relatively simple. The final reaction that occurs is that copper (0 valence) is converted into copper ions (+2 valence), and its side reaction will also partially produce copper ions (+1 valence); the anode of the insoluble anode The reaction is an electrocatalytic reaction process involving the precious metal oxide coating on the surface of the titanium anode. The basic reaction is the anode reaction of electrolyzing water, and the final products are oxygen and hydrogen ions. During this reaction process, not only will the coating cause a large amount of decomposition of the additives in the plating solution through contact, but the reaction will also produce strongly oxidizing intermediates including oxygen atoms, hydroxyl radicals, etc., which will also cause additional decomposition of the additives. This creates a very big obstacle to the use of insoluble anodes - compared with soluble anodes, insoluble anodes will cause additional additive consumption and significantly increase the operating costs of the PCB copper plating process.
davomida elektroplating jarayoni, the anod end the insoluble anod o'tadi a reaksiya of elektrolizing suv, va bu reaksiya ning standart elektrod potentsiali bu reaksiya dan sezilarli darajada yuqori bo'ladi 1 eriydigan anod. At the same time, chunki titan ning qarshiligi mis; dan katta va, umumiy, yuqori oqim zichligi ko'pincha ishlatilganda titan anodlardan foydalanganda ishlatiladi. Bu natija 1V, dan katta bo'lgan kuchlanish 1V dan katta bo'lgan eriydigan anodlardan yuqori bo'ladi. Solishtirilganda titan anodlar ishlatiladi. Bu voltaj farq kamida katta 1V, yoki hatto 2V. Solishtirilganda bilan kuch ta'minoti mos fosfor mis balls, the voltage design of the power supply for insoluble anodes needs to be considered in advance. Kurs, from a cost perspective, the cost the 2c 2c to 2c to 2c to 2c to 2c to 2c 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0kuch taʼminot will also artish shunga yarasha.
3. Advantages and disadvantages of titanium anodes
3.1 Advantages of titanium anodes
On the one hand, titanium anodes can operate at higher current densities. Due to the passivation of the phosphide film on the surface of the phosphor copper ball, the maximum operating current density of the phosphor copper ball cannot exceed 2.5~3 ASD; while the maximum current density that the titanium anode can withstand is dozens of times that of the phosphor copper ball (for example, in In the field of steel electroplating, the working current density of titanium anodes can reach more than 100 ASD). Therefore, through the support of equipment and matching of corresponding electroplating conditions, titanium anodes have the potential to achieve higher equipment productivity and production efficiency.
On the other hand, titanium anodes avoid the production interruption problems caused by regular addition and maintenance of the phosphor copper ball process. When using phosphor bronze balls, the consumed phosphor bronze balls must be replenished at regular intervals. Before adding new phosphor bronze balls, they need to be cleaned. They cannot be produced immediately after adding them. It takes a certain period of electrolytic cylinder operation to form a phosphating film on the surface. The phosphor bronze balls that have been used for a long time are close to the residue state, so they must be completely cleaned out of the titanium basket to avoid electroplating quality problems. These unavoidable maintenance operations make copper plating equipment using phosphor bronze balls not only unable to operate uninterrupted for a long time, but also consume a lot of manpower. When using titanium anodes, the copper oxide powder adding device for replenishing copper ions is independent, and there is no need to shut down the machine to replenish copper oxide powder. At the same time, the titanium anode itself is also "maintenance-free", that is to say, during the life cycle of the titanium anode, in principle, there is no need for additional cleaning of the titanium anode. Therefore, using titanium anodes can theoretically achieve completely uninterrupted production, thus saving a lot of maintenance time and manpower investment.
On the other hand, the use of phosphor copper balls is more likely to cause contamination of the plating solution, leading to premature failure of the plating additives. Phosphor copper balls are processed by smelting and rolling, while copper oxide powder is produced by dissolving the copper raw material in the solution, further purifying and precipitating the copper oxide precursor in the solution, and finally calcining it. Copper oxide powder. Compared with the two processing processes, the processing process of copper oxide powder is more convenient to control the purity of raw materials. Relatively speaking, under good control conditions, the impurity content in copper oxide powder will be lower than that of phosphor copper balls. During long-term use, whether it is phosphor copper balls or copper oxide powder, impurities will dissolve and accumulate in the plating solution. Electroplating additives are often quite sensitive to the content of impurity ions in the electroplating solution. When the impurity ions in the electroplating solution reach a certain concentration, they will affect the effect of the electroplating additives, thereby adversely affecting the electroplating effect. Therefore, the electroplating system using titanium anodes can maintain the bath liquid in a relatively low pollution state and make the bath liquid last longer. This not only reduces the additional cost of tank preparation caused by the premature failure of the plating bath, but also reduces the cost of the bath during use. The impact of impurities will also be more assured.
In terms of equipment design, the use of phosphor bronze balls limits the design of the equipment, because the phosphor bronze ball system cannot get rid of the combination mode of "phosphor bronze balls-titanium basket-anode bag". This phosphor bronze ball system also determines the electroplating method. It is a vertical plating method. Using titanium anodes can completely get rid of the vertical plating mode. Since titanium anodes can be completely customized, the equipment's jet flow, circulation, anode distribution, anode shape and other aspects can be redesigned and optimized. This gives the equipment a variety of possibilities and also provides electroplating equipment capabilities (such as The further improvement of electroplating uniformity, operating current density, etc. provides prerequisites.
3.2 Disadvantages and selection of titanium anodes
On the one hand, the titanium anode must have a corresponding service life. After a period of use, the discharge performance or electroplating performance of the titanium anode will decline, and it may even be unable to continue to meet the high requirements of electroplating. Generally, titanium anodes need to be evaluated and replaced after 1 to 2 years of use. The replacement cost of titanium anode is much greater than that of titanium basket of phosphor bronze ball system.
3.3 Selection of titanium anode
Choosing titanium anode is a choice between cost and quality. On the one hand, the use of titanium anodes can actually improve process capabilities and improve product quality. In some cases, the use or not of titanium anodes determines whether a manufacturer has the manufacturing capabilities of a certain product; on the other hand, , the use of titanium anodes will be an obvious improvement compared to phosphor bronze balls, both in terms of one-time equipment investment costs and subsequent operating costs. When the benefits outweigh the costs, it is clear that titanium anodes will indeed be the natural choice. Moreover, in some cases, if titanium anodes are not used, the manufacturing ability of a certain product will be lost, titanium anodes have become an inevitable choice. As product demand continues to increase, improvements in process capabilities are also ongoing requirements. In the long run, choosing titanium anodes will inevitably be an increasingly certain development direction.
