Let's understand the phosphor copper ball in PCB design

With the rapid development of electronic information technology, the demand for various PCB production and manufacturing has greatly increased. As the key raw material for anodizing in electroplating process, the demand for copper is greatly increased, in which the high-precision PCB must be anodized with phosphor copper ball. The phosphor copper ball is mainly used for electronic devices PCB, especially for the key components indispensable to electronic devices such as the collaborative innovation of double-layer PCB. It relies heavily on high-quality PCB phosphor copper ball anodizing as the basic raw material for manufacturing PCB. Therefore, th PCB phosphor e demand for nickel alloy anodizing balls is very large. The key part of this article is the phosphor copper ball of PCB. First, it introduces in detail whether the copper ball containing phosphorus needs to be used for PCB copper electroplating. Second, it discusses the overview of the application of phosphor copper ball in PCB and the forecast of the worldwide sales market of phosphor copper ball. In fact, let's follow the small editor to know.

PCB design

Phosphor copper ball in detailed explanation

Whether phosphorus containing copper ball is required for PCB copper electroplating

In the early days, copper sulfate electroplating process used electrolytic copper or T2 oxygen free copper as the anode oxidation, and the output power of the copper ball of the anode oxidation power switch was up to 100% hg or even over 100%, which formed a series of problems: the copper content in the bath continued to rise, the consumption of preservatives was accelerated, the vermicelli and anode mud in the bath increased, the output power of the anode oxidation application was reduced, and the copper ball with extremely high coating was used as the burr and unsmooth defects.

In 1954, Neverse and others in the United Kingdom discussed anodic oxidation and found that adding a very small amount of phosphorus in anodic oxidation can be solved by titanium electrode after a period of time (the anodic oxidation black film of titanium electrode is a proper key to the electroplating process, so it is believed that the application of titanium electrode drag cylinder plate/false plating plate/wave plate under the current intensity of 2-3ASD gate valve copper ball for 4-10 hours), and the surface of copper anodic oxidation will be transformed into layers of gray black phosphorus film, The main component is phosphating copper Cu3P. This layer of black film has the conductivity of metal materials, which has changed some strong reaction system processes in the process of copper anodic oxidation and melting system, effectively defeated some of the said defects, and played a key role in the quality of copper and the reliability of processing technology.

The dissolution of copper anodic oxidation is mainly converted into divalent copper ions. The discussion and experiment confirmed that (rotating ring disk electric level and constant current flow method): the copper dissolution in copper sulfate solution is carried out in two steps.

Cu-e - → Cu+primitive strong response 1

Strong response of Cu+-- e - → Cu2+primitive 2

The oxidation of cuprous ions into divalent copper ions by air under the effect of anodic oxidation is a slow and strong reaction, and it can also be converted into divalent copper ions and simple copper after a strong reaction of disproportionation, as in the strong reaction of organic chemical copper deposition. The converted copper element is deposited in the coating by the method of electrophoresis principle, thus causing vermicelli, rough edges, and unsmooth. When a small number of phosphors are enrolled in the anodic oxidation process, they will be transformed into gray black phosphorous films on the anodic oxidation surface through the solution of titanium electrode (or dragging cylinder), and the process of anodic oxidation melting system will be changed:

1. The gray black phosphorus film has significant catalytic activity for the strong reaction 2 of the unit, greatly accelerating the air oxidation of cuprous ions, turning the slow strong reaction into fast strong reaction, and greatly reducing the accumulation of East Asian copper ions in the tank solution. The phosphorus film on a piece of anodized surface can also prevent cuprous ions from entering the tank, promote their air oxidation, and reduce cuprous ions entering the tank. The error between two wires of standard anodized gray black nickel alloy film is 1.5&TImes; 104 Ω - 1CM-1, with the conductivity of metal materials, is not easy to harm the conductivity of anodic oxidation, and the anodic oxidation of spring copper anodic oxidation of nickel alloy anodic oxidation wall has a small anodization. When Da is 1ASD, the anodic oxidation potential difference of copper anodic oxidation containing 0.02 -- 0.05% phosphorus is 50? Lower than that of T2 oxygen free copper anodic oxidation? The 80 mv gray black anodized phosphorus film is not easy to form anodic oxidation passivation treatment under the agreed current intensity.

2. The gray black phosphorus film on the anodized surface will cause the abnormal dissolution of anodizing, greatly reduce the falling of slender particles, and further improve the application output power of anodizing. When the anodic oxidation adopts 0.4? 1.2 At ASD current intensity, the phosphorus content in anodic oxidation is linearly related to the black film thickness. The water content of anodized phosphorus is 0.030? 0.075% anodic oxidation has the highest output power, and the gray black phosphorus film of anodic oxidation is the best.

Cuprous ions can also occur in the process of cathodic deposition system:

Cu2++e-→Cu 3

Cu2++e - → Cu+slow strong response 4

Cu++e - → Cu fast strong response 5

The cuprous ions in the plating solution are mainly affected by the strong reaction and strong reaction of anodic oxidation. Although the water content is very slim, only a few of them can damage the coating quality. Copper ions entering the bath will do harm to the cathodic coating:

1. The rough edge of the composition coating is not smooth,. In the process of electroplating process system, vermicelli are deposited on the cathode coating by the method of electrophoresis principle. When the current intensity is low and the temperature is high, the output power of the cathode electric flow decreases, and the hydroxide ion is charged and discharged to reduce the acid value. The strong reaction of hydrolysis is carried out in the direction of beneficial vermicelli, and the burrs will become worse.

2. The cuprous ions together will form a coating that is not bright, has poor leveling ability, and the plating solution is turbid. This is because the vermicelli are delicately spread on the cathode coating, and the ability to form the stacking layer is poor, which is dim. In the low electric flow area, the harm is not optimistic. At this time, adding light agent has little effect. Add hydrogen peroxide to remove the vermicelli, drive away the complete hydrogen peroxide, and fill in light agent. The brightness and flatness of the area will be significantly improved. A strong reaction will consume some acid, so some hydrochloric acid should be properly filled.

The phosphorus content of anodic oxidation is 0.3% in China. Overseas discussions indicate that the phosphorus content of anodic oxidation of nickel alloy reaches about 0.005%, which is composed of black film, but the film is too thin and has poor adhesion; The water content of phosphorus is too high, the black film is too thick, the anode sludge is too much, and the solubility of anodic oxidation is poor, resulting in the reduction of copper content in the plating solution. The water content of anodized phosphorus should be 0.030-0.075%, preferably 0.035? 0.070%. China's production machinery and equipment and processing technology are outdated, and the mixing is not symmetrical, so the phosphorus content cannot be guaranteed to be evenly distributed. Generally, the phosphorus content is increased to 0.1-0.3%; In overseas, titanium electrode or T2 oxygen free copper and phosphorus alloy copper are used as materials, and the medium frequency induction furnace is used for smelting. The materials have high purity, the phosphorus content is easy to manipulate, the medium frequency magnetic induction is used, and the magnetic field stirring effect is good. The copper and phosphorus melting and stirring are symmetrical, and the full automatic manipulation is used. The copper anodized phosphorus made in this way is evenly distributed, dissolved, and the crystal is detailed, the crystal is thin, and the application rate of anodic oxidation is high, which is beneficial to the lubrication and brightness of the coating, The burr and unsmooth defects are reduced.

Harm of Phosphorus Water Content on Anodic Phosphorus Oxide Film

1. The water content of phosphorus is 0.030? 0.075% copper anodizing, the black film is moderately thin and thick, the structure is fine, the fusion is firm, and it is not easy to fall; Anodizing of copper with high phosphorus water content before explosion. The phosphorus dispersion is not symmetrical, and the anode mud is too much due to the dissolution, which will pollute the tank liquid, block the anodic oxidation bag hole, and increase the working voltage of the tank. When the working voltage of the tank rises, the anodic oxide film will fall. In practical production, the simple rough edges caused by anodizing are removed and replaced while the electroplating process is in progress.

2. Anodized phosphorus of nickel alloy with 0.3% water content of phosphorus is distributed unevenly, the gray black phosphorus film is too thick, and the solubility of copper is poor. Therefore, it is often necessary to fill up the anode oxidation, not to make the ratio of the total area of the anode and cathode 1:1. In practice, there are many copper anodic oxidation hanging, and the copper water content in the bath also has a trend of decreasing, and there is no way to persevere in balancing. It is not cost-effective to add copper sulfate frequently from the perspective of electroplating process cost. The electroplating process prefers to hang more nickel alloy anode oxidation of the leftovers, and the cost of practical activities will increase with the increase of anode mud.

3. In practice, the black film formed by copper anodizing with high phosphorus content is too thick. With the addition of the resistor, the original current should be maintained and the working voltage should be increased. The increase of the working voltage of the cell is beneficial to the charging and discharging of hydroxyl ions, and the probability of needle eye is increased. This situation affects the 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, and other wet refrigerants need to be added, and the working voltage should be reduced by every means.

4. In practice, the phosphorus content is high, the black film is too thick, the distribution is uneven, and the low current flow area is not bright, thin and sandy.

Although the thickness of 0.3% phosphorous copper anodizing black film can reduce the amount of cuprous ions entering the tank, its loose structure and uneven distribution greatly reduce its efficacy. There is a strong reaction of organic chemical reversibility in other lithium battery electrolytes:

Cu2++ Cu -→ 2Cu+

At room temperature, the equilibrium constant of this strong response is K=(Cu+) 2/(Cu2+)=0.5X10-4

As the temperature rises, the concentration of cuprous ions will also rise. The cuprous ion is stored in the tank solution by the method of cuprous hydrochloride, and is oxidized by air when the gas is stirred. When the acid value decreases, cuprous chloride hydrolyzes and oxidizes cuprous oxide (vermicelli). The same powder stays in the high current area of the cathode and deposits a certain amount of it, which is the raw edge; In the low current flow area, the current output power decreases, more hydroxide ions are charged and discharged, the relative acid value decreases, and the hydrolysis reaction is carried out in the direction of converting into vermicelli,

Cu2SO4+H2O=Cu2O+H2SO

More vermicelli will stay on the cathode surface to form a cathode coating which is not bright and fine hemp sand. If there is no gas stirring and the current intensity is not large, this situation is very common in the low current flow area.

Copper anodizing with less phosphorus water content is applied. Because the gray black phosphorus film is delicate, the cuprous lizon cannot be mixed into the tank solution. As long as gas is used to stir, it is not necessary to lower the concentration value of hydrochloric acid, and the current intensity is slightly higher, so that the amount and grit in the area can be defeated.

Whether phosphorus containing copper ball is required for PCB_ Application of phosphor copper ball in PCB

Application of phosphor copper ball in PCB

1. The phosphor copper ball is used in one of the PCB boards for copper recovery and re copper manufacturing, which is mainly determined by the conductive copper layer that generates buried holes

For PCB products with two or more layers, because the routes between different layers of boards are not connected immediately, it is necessary to connect the routes between different layers of boards through the structure of the guide hole to facilitate the transmission of polarity.

In the soldering of PCB board, after the route making of inner multilayer board, multilayer pressing and mechanical equipment hole turning, in order to make the hole turn on and off, the program flow of removing glue residue, hair removal and organic chemical copper must be carried out to convert into a thin copper layer. Then, roll back plating and re roll plating are carried out by penetrating the titanium electrode barrel plating method to improve the thickness of the copper layer to enhance the conductivity of the guide hole. Phosphorus copper ball is an important raw material for primary copper and secondary copper.

2. Phosphorus copper ball is the anode oxidation raw material of PCB barrel plating solder. Adding phosphorus to the copper ball can avoid the harm of copper to the quality of a thin film

Phosphor copper ball plays the role of anodic oxidation in PCB electroplating process tank, so it is also called anode copper ball. When the titanium electrode reaction is just started, the copper molecules in the phosphor copper ball will lose electronic devices and generate copper ions. The positively charged copper ions will move to the PCB to be plated that belongs to the cathode, and finally get electronic devices on the surface of the PCB and convert them into copper films.

In basic theory, phosphorus does not participate in the reflection of PCB barrel plating, and the purpose of phosphorus addition depends on the dissolution rate of copper molecules. If the dissociation rate of copper molecule is too fast, a lot of cuprous ions will be caused, and the 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 the PCB by the method of electrophoresis principle, which will endanger the conversion of copper coating into structure and deteriorate the quality of copper coating.

Whether phosphorus containing copper ball is required for PCB_ Application of phosphor copper ball in PCB

Prediction of the worldwide sales market of phosphor copper ball

1. The development trend of PCB manufacturers moving to the mainland will not change, and the main performance of phosphor copper ball talent is also the mainland sales market.

The proportion of China's PCB annual output value in the world has increased rapidly from 8.5% in 2000 to 25.2% in 2019. Because the development trend of PCB products moving to the mainland for production and manufacturing continues to grow, the total value of PCB in the mainland has reached the first in the world at this stage.