With the rapid development of electronic information technology, the manufacturing requirements of various circuit boards have increased greatly. As the key raw material of anodizing in electroplating process, the demand of copper is greatly increased, and the high-precision PCB must be anodized with phosphor copper balls. Phosphor copper balls are mainly used in electronic devices PCB circuit boards, especially in collaborative innovation of double-layer PCB circuit boards, which are indispensable key components of electronic devices. It relies heavily on high-quality PCB phosphor copper balls anodizing as the basic raw material for manufacturing PCB circuit boards. Therefore, the demand of nickel alloy anodized balls is very abundant. The key point in this paper is the phosphor copper ball of PCB. Firstly, it introduces in detail whether the phosphor copper ball needs to be used in electroplating copper on PCB. Secondly, it discusses the application overview of phosphor copper ball in PCB and its worldwide sales market forecast. Actually, let’s get to know each other.
Detailed explanation of phosphor copper balls in PCB design
Do you need to use phosphorus-containing copper balls for electroplating copper on PCB?
In the early days, electrolytic copper or T2 oxygen-free red copper was used for anodizing in the copper sulfate electroplating process, and the output power of the copper ball of the anodizing power switch was as high as hg100% or even over 100%, which constituted a series of problems: the water content of copper in the bath continued to rise, the consumption of preservatives accelerated, the vermicelli and anode mud in the bath increased, the output power of anodizing application decreased, and the coated copper ball with high artwork was used as burrs and unsmooth defects.
In 1954, Neverse, England, etc. discussed the anodic oxidation, and found that after a period of time, the anodic oxidation of titanium electrode was solved (the black film on the anodic oxidation of titanium electrode was the key to the electroplating process, so it was considered that titanium electrode was used to drag the cylinder plate/dummy plating plate/wave plate under the current intensity of 2-3ASD gate valve copper ball for 4-10 hours), and the anodized surface of copper was transformed into layers of gray black phosphorus film. This black film has the conductivity of metal materials, which changes some strongly echoed system processes in the process of copper anodizing and melting system, effectively defeats some of the said defects, and plays a key role in the quality of copper and the reliability of processing technology.
The melting of copper by anodic oxidation is mainly converted into divalent copper ions. The discussion experiment proves that the melting of copper in copper sulfate solution is carried out in two steps (rotating ring-disk electrode and constant current method).
Cu-e-→Cu+ elementary strongly reverberated 1
Cu+-E-→ Cu2+elementary strongly reverberated 2
The air oxidation of cuprous ions to bivalent copper ions under the effect of anodic oxidation is a slow and strong reaction, and it can also be transformed into bivalent copper ions and elemental copper through disproportionation, just like the strong reaction of copper deposition in organic chemistry. The converted simple substance of copper was deposited in the coating by electrophoresis principle, which resulted in vermicelli, rough edges and unsmooth appearance. When a small amount of phosphorus is registered in the anodizing process, it is solved by titanium electrode (or dragged tank) and transformed into layers of gray-black phosphorus film on the anodized surface, and some changes occur in the melting system process of anodizing:
1. The gray-black phosphorus film has obvious catalytic activity for the strong response of the elementary element 2, which greatly accelerates the air oxidation of cuprous ions, turns the slow strong response into the fast strong response, and greatly reduces the accumulation of East Asian copper ions in bath solution. A piece of phosphorus film on the anodized surface can also prevent cuprous ions from entering the bath solution, promote its air oxidation, and reduce the cuprous ions entering the bath solution. The error between two lines of standard anodized gray-black nickel alloy film is 1.5&TImes; 104Ω-1CM-1, which has the electrical conductivity of metal materials, and it is not easy to harm the electrical conductivity of anodic oxidation. Moreover, the anodic polarization of spring copper anodizing with nickel alloy anodizing wall is small. When Da is 1ASD, the anodic potential difference of copper anodizing with 0.02-0.05% phosphorus is 50? lower than that of T2 oxygen-free red copper anodizing. 80mv. The gray-black anodized phosphorus film is not easy to form the passivation treatment of anodic oxidation under the agreed current intensity.
2. The gray-black phosphorus film on the surface of anodic oxidation will make anodic oxidation melt abnormally, and the situation of slim particles falling down will be greatly reduced, and the applied output power of anodic oxidation will be further improved. When anodizing is 0.4? 1.2 At ASD current intensity, the phosphorus content in anodic oxidation is linearly related to the thickness of black film. When the water content of anodized phosphorus is 0.030? The application output power of 0.075% etching anodizing is the largest, and the conversion of anodized gray-black phosphorus film is the best.
Cuprous ions also occur in the process of cathodic deposition system:
Cu2++e-→Cu 3
Cu2++e-→Cu+ slow strong response 4
U++E-→ Cu Fast Strong Response 5
Cuprous ions in the plating bath are mainly caused by strong reaction and strong reaction of anodic oxidation. Although the water content is slim, only a few of them can harm the coating quality. Cuprous ions entering the bath will do harm to the cathode coating;
1. The raw edges of the composition coating are not smooth. During the electroplating process system, vermicelli was deposited on the cathode coating by electrophoresis principle. Under the condition of low current intensity and high temperature, the output power of cathode current decreases, and hydroxide ions are charged and discharged, so that the acid value decreases, and the strong reaction direction of hydrolysis reaction develops to the direction of beneficial vermicelli transformation, and the condition of burrs will be aggravated.
2. Together, cuprous ions will make up the coating which is not bright, has poor leveling ability, and the plating solution is turbid. It’s all because the vermicelli is finely spread on the cathode coating, and the delicate ability of forming the accumulation layer is poor and dull. In the low current area, the harm is even less optimistic. At this time, the effect of adding light agent is not great. Adding hydrogen peroxide to remove vermicelli, driving out complete hydrogen peroxide and filling up light agent will obviously improve the brightness and smoothness of the area. A strong reaction together will consume some acid, so some hydrochloric acid should be properly filled.
The water content of phosphorus in anodic oxidation is more than 0.3% in China. Overseas discussions indicate that the water content of phosphorus in anodic oxidation of nickel alloy reaches about 0.005%, and it has a black film composition, but the film is too thin and the bonding property is not good. Too high phosphorus content, too thick black film, too much anode sludge and poor anodic oxidation solubility lead to the decrease of copper water content in the bath. The water content of anodic phosphorus oxide is 0.030-0.075%, preferably 0.035? 0.070%. China’s production machinery, equipment and processing technology are outdated, and the mixing is not symmetrical, which can’t guarantee the symmetrical distribution of phosphorus water content. Usually, the phosphorus water content is increased to 0.1-0.3%; The overseas titanium electrode or T2 oxygen-free red copper and phosphorus alloy copper is used as the material, which is smelted by an intermediate frequency induction furnace. The purity of the material is high, and the water content of phosphorus is easy to control. The medium frequency magnetic induction is adopted, and the magnetic field stirring effect is good. The copper and phosphorus are melted and stirred symmetrically, and the fully automatic operation is realized. The copper anodized phosphorus prepared in this way has a well-proportioned dispersion, a well-proportioned melting and melting, detailed crystals, slim crystals, and high application rate of anodizing, which is beneficial to moistening and brightening the coating, and reduces burrs and unsmooth defects.
The harm of water content of phosphorus to anodized phosphorus film
1. The water content of phosphorus is 0.030? 0.075% copper is anodized, and the black film is moderately thin, fine in structure, firm in fusion and not easy to fall. Anodizing of copper with too high water content of hazardous phosphorus. The uneven dispersion and melting of phosphorus will lead to excessive anode mud, which will pollute the bath solution and block the anodic oxidation pocket, thus increasing the working voltage of the bath. When the working voltage of the cell rises, the anodic oxide film may fall. In the practical production, the simple burrs caused by anodic oxidation are removed and replaced while electroplating.
2. Anodized phosphorus of nickel alloy with phosphorus water content of 0.3% spreads unevenly, the gray-black phosphorus film is too thick, and the solubility of copper is poor. Therefore, it is often necessary to fill the anodic oxidation, instead of making the ratio of the total area of anode and cathode 1:1. In practice, the anodic oxidation of copper is more frequent, and the water content of copper in bath solution also tends to decrease, and there is no way to persist in balancing. It is often necessary to add copper sulfate, which is uneconomical from the perspective of electroplating process cost. In electroplating process, it is preferable to hang more nickel alloy scraps for anodizing, and the anode mud will increase, and the cost of practical activities will also increase.
3. In practical activities, the black film formed by anodic oxidation of copper with high phosphorus water content is too thick. When resistors are added, the original current should be kept and the working voltage should be increased. The increase of working voltage is beneficial to the charge and discharge of hydroxide ions, and the incidence probability of needle eye increases. This situation has a negative impact on domestic “M.N.SP.P”. AEO “system software is rare, because there are many surfactants in it, but for some imported optical agents, the opportunity of needle eye will be greatly increased, so it is necessary to add other wetting and cooling agents and try every means to reduce the working voltage.
4. In practical activities, phosphorus has high water content, thick black film, uneven distribution, and it will also form a low current area which is not bright, slim and sandy.
Although the thin and thick black anodic oxide film containing 0.3% phosphorus can reduce cuprous ions from entering the bath solution, its structure is loose, its dispersion is uneven, and its efficacy is greatly reduced. Other lithium battery electrolytes have strong reaction of organic chemical reversibility:
Cu2++ Cu -→ 2Cu+
At room temperature, the equilibrium constant of this strong reaction is K=( Cu+)2/( Cu2+)=0.5X10-4.
As the temperature rises, the concentration of cuprous ions will also rise. Cuprous ions exist in the bath solution in the form of cuprous hydrochloride, and are oxidized by air when the gas is stirred. When the acid value is reduced, cuprous hydrochloride hydrolyzes cuprous oxide (vermicelli), and the same powder stays in the cathode high current area, and the inevitable amount of deposition is the raw edge of the disease. In the low current area, the output power of the current decreases, the hydroxide ions are charged and discharged more, the acid value decreases in this area, and the hydrolysis reaction develops in the direction of turning into vermicelli.
Cu2SO4+H2O=Cu2O+H2SO4
More fans staying on the surface of the cathode will form dull cathode coating and fine hemp sand. If there is no gas stirring, the current intensity will not turn up much, which will happen in the low current area.
Copper anodic oxidation with low phosphorus content is applied, because the gray-black phosphorus film is delicate, and the cuprous force can’t be integrated into the bath solution. As long as gas is stirred, the concentration of hydrochloric acid does not have to be slightly lower, and the current intensity is slightly higher, the area can be defeated not only in quantity but also in the shape of hemp and sand.
Do you need to use phosphorus-containing copper balls in PCB? Overview of application of phosphorus-containing copper balls in PCB
Overview of application of copper balls in PCB
1. Phosphor-copper balls are used in the process of copper recycling and copper recycling of PCB, which depends on the conductive copper layer with buried holes.
For PCB products with about two layers, because the routes in the middle of different multilayer boards are not immediately connected, it is necessary to penetrate the structure of buried holes to connect the routes in the middle of different layers, so as to facilitate the transmission of polarity.
In the soldering of PCB, after the route making of inner multilayer board, multilayer pressing and mechanical equipment hole turning, in order to make the hole turning on and off, it is necessary to carry out the procedures of removing glue residue, hair removal and organic chemical copper, and transform it into a thin copper layer. Then, through the method of titanium electrode barrel plating, a roll-back plating and a roll-back plating are carried out, and the thickness of the copper layer is increased to enhance the conductivity of the via hole. Phosphorus ball is an important raw material for primary copper and secondary copper.
2. Phosphorous copper ball is the anodic oxidation raw material of PCB barrel plating solder. Adding phosphorus to the copper ball can prevent cuprous from endangering the quality of a thin film.
Phosphor copper ball plays the role of anodic oxidation in PCB electroplating bath, so it is also called anodic copper ball. When the reaction of titanium electrode is just beginning, the copper molecules in the phosphor-copper ball will lose electronic devices and produce copper ions. The positively charged copper ions will move to the PCB to be plated to which the cathode belongs, and finally the electronic devices will be obtained on the surface of the PCB and converted into copper films.
Theoretically, in the reflection of PCB barrel plating, phosphorus does not participate in the reflection, and the purpose of phosphorus addition depends on alleviating the dissolution rate of copper molecules. If the dissociation rate of copper molecules is too fast, a lot of cuprous ions will be produced, and two cuprous ions will reflect each other as copper molecules and copper ions. The copper molecules in the aqueous solution will be arbitrarily adsorbed on PCB by electrophoresis principle, which will endanger the transformation of copper coating into structure and deteriorate the quality of copper coating.
Do you need to use phosphorus-containing copper balls in PCB? Overview of application of phosphorus-containing copper balls in PCB
Forecast of worldwide sales market of copper balls
1. The development trend of PCB manufacturers moving to the mainland will not change, and the main performance of phosphor copper balls is the best in the mainland sales market.
The annual output value of PCB in China’s mainland increased rapidly from 8.5% in 2000 to 25.2% in 2019. Because the development trend of PCB products moving to the mainland for manufacturing is booming, the total value of PCB in the mainland has reached the first place in the world at this stage.
It is estimated that the worldwide sales market of phosphor copper balls will increase from 146,501 tons in 2003 to 192,988 tons in 2008, with CAGR(03-08) being 5.7%. Among the regions, the talents of the inland regions are the best, with CAGR(03-08) reaching 10.1%.
2. In the past, phosphor copper balls were mainly raised by beating American and Japanese manufacturers. After the successful selection of Taiwan and mainland factories, two existing companies appeared.
Copper balls do great harm to the quality of PCB. In the past, Japanese companies Mitsubishi and Asaba； chose this industry. IMC from America, UniverTIcal and Outokumpu from Germany.
In recent years, because the Asia-Pacific region has become an important place for PCB manufacturing, local manufacturers in Taiwan Province and the mainland of China have invested in the research and development and burning of phosphor copper balls. At present, successful manufacturers include Dongyouyue in Taiwan Province, China, and Xijiang electronic devices in mainland China. According to the sales volume claimed by the manufacturers, these two manufacturers have surpassed other investors and ranked among the top two places in the world.