Detection Of Additives In Electrolytic Copper Foil Plating Bath And Research On Anti-corrosion Performance

Copper foil,as an important part of printed circuit boards and lithium ion batteries,causes millions of economic losses due to corrosion every year.Therefore,the study of surface coatings to improve the corrosion resistance of copper foil and reduce economic losses has important research significance.Organic additives have been widely used in the preparation and surface treatment of electrolytic copper foils because of their ability to improve the stability of electroplating solution,dispersion ability,deep plating ability and coating structure.However,the effective concentration of the additive is difficult to know due to the problems of decomposition,agglomeration and failure of the additive in the plating process.Therefore,it is of guiding significance to accurately control the content of the additive in the plating solution for the production of high-quality copper foil in China.At present,the detection methods of each additive in aqueous solution mainly include spectrophotometry,inductively coupled plasma mass spectrometry,titration and electrochemical method,etc.,but using these methods alone cannot avoid the interference of a large number of copper ions and sulfuric acid in the plating solution.Therefore,exploring a suitable method to quickly and accurately detect the concentration of additives in the acid copper plating solution has important scientific research value and application prospects.In this paper,the basic principle and sample analysis of organic addition in copper acid plating solution by UV spectrophotometry were systematically studied.At the same time,the electrochemical assisted silane coupling agent was used to modify the GO coating to improve the corrosion resistance of copper foil.The detailed content and results of the paper are as follows:1.We introduce the related contents of this article,such as electrolytic copper foil,additive types,additive content detection and corrosion resistance,the influence of various components in the plating solution are explained on the performance of copper foil.And further,we cite exampless to state the current research status of the content detection of each component and copper foil corrosion resistance.Finally the research content and innovation point are described of this work.2.The structural characteristics of polyethylene glycol(PEG)in copper acid plating solution were studied.Combined with the principle of UV spectrophotometry and the luminescence principle of the ion association compound formed by color reagent and PEG,the linear relationship between absorbance and the concentration of PEG was established.The detection method for PEG in the traditional non-acid copper solution cannot avoid the interference of copper ions and hydrogen ions in the plating solution.By adjusting the pH value of the plating solution,the PEG is separated by the principle of the density difference between the copper hydroxide precipitation and the PEG solution under neutral conditions.According to Lambert Beer's law,PEG has a good linear relationship in the range of 1-30 mg/L,and the linear correlation coefficient is greater than 99%,which provide technical support for the subsequent determination of PEG content in acid copper plating bath.3.The properties of bis(3-sulfopropyl)disulfide in copper acid plating solution were studied.We combine the principle of ultraviolet spectrophotometry and the luminescence principle of color reagent and bis(3-sulfopropyl)disulfide,the linear relationship between absorbance and the concentration of bis(3-sulfopropyl)disulfide was established after eliminating the interference of copper ions and hydrogen ions in the plating solution.We analyze the content of copper ions by EDTA complexometric titration using ammonium violurate as the color developing agent.And the concentration of sulfuric acid in the plating solution was quantitatively analyzed based on the barium sulfate precipitation method and the principle of electric neutrality of the solution.These methods provide data support for the subsequent determination of additives and main salt components in unknown baths.4.The structural characteristics of gelatin in the acid copper plating bath were studied.The electrochemical method and the combination of Kjeldahl Method and Salicylic Acid Method were used to determine the content of gelatin in the plating bath.The influence of gelatin on the oxygen uptake potential and the color principle was explained.We establishes the linear relationship between gelatin concentration and oxygen uptake potential and absorbance.5.In view of the traditional silane coupling agent modified graphene oxide coating to improve the corrosion resistance of copper foil,there are problems such as easy cracking of the coating and unstable performance.An electrochemical-assisted silane coupling agent modified graphene oxide coating method was proposed.Under the action of direct current,the copper foil coated with graphite oxide is used as the cathode.The surface of the copper foil is locally alkalized,which is conducive to the formation of the network cross-linked structure of the silane coupling agent,and the graphene oxide is reduced at the same time.The corrosion resistance of the coating prepared by this method is as high as 98.44%,and the contact angle is 103.3°C,which significantly improves the corrosion resistance and hydrophobicity of the copper foil.