When using the chemical copper plating solution, why does the hole wall burst? There are many possible reasons. Let's first discuss two of them.
The drill bit is not sharp enough and there is still resin residue on the hole wall.
What is "dust removal"? We know that when drilling holes on printed circuit boards, there is a brief period of high temperature. Since the resin-based substrate of the printed circuit board is a poor heat conductor, the heat accumulates. When the surface temperature of the hole wall exceeds the glass transition temperature of the resin, a thin layer of resin stain will form on the hole wall.
If only a conventional oil removal process is carried out after drilling and then the chemical copper plating solution is used, since the conventional oil removal solution cannot remove resin stains, it will cause the copper coating to be discontinuous, resulting in the inability of the inner layer signal lines of the multi-layer board to be connected or the connection being unreliable. Removing the drill stains is to remove the stains after drilling, in order to improve the surface performance of the hole wall.
During the process of removing the burrs, if it is not done properly, it may easily lead to the occurrence of pore bursting after electroless copper plating. To avoid such a situation, we need to enhance the ability to remove the burrs.
The chemical copper coating is uneven and has voids.
The reason for this is that there is a problem with the deposition rate of the chemical copper plating solution. So, what are the factors of the plating solution composition that affect the deposition rate? Besides the copper salts and alkaline solution mentioned in the previous article, there is another reducing agent. Let's discuss the impact of this component on the deposition speed in detail.
The reducing agent in the solution needs to have a certain concentration. When the concentration of the reducing agent is lower than 3 mL/L, the deposition speed of electroless copper plating decreases, and at the same time, the side reactions intensify. Therefore, when using the electroless copper plating solution HSECu-801 by Bigray, the concentration of the reducing agent is recommended to be controlled within 5.5 - 6 mL/L. At the same time, the electroplating plant also needs to control the copper salts and alkaline components in the plating solution well, which is the basis for ensuring a stable deposition speed and preventing problems such as missed plating and cracking of the hole wall.
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Guangdong Bigely Technology Co., Ltd. ,founded in 2003, is a high-tech enterprise integrating R & D，production, sales and service, specializing in the production of electroplating chemicals. As a fast growing electroplating chemicals supplier in China, Bigely has over 20 years' experience in electroplating additives production and own production base of 5000 square meters. We can produce 15,000 tons of electroplating additives every year, which can fully meet the needs of customers.
If you need our high-quality electroplating additives, please contact us. We can provide you samples for test, and also provide a series of services.
