Study On Surface Treatment Process And Properties Of High Temperature Heat Resistant Coating Of Electrolytic Copper Foil

As one of the basic raw materials of the electronics industry,which is mainly used in the printed circuit board?PCB?and copper clad laminate?CCL?,electrolytic copper foil plays a important role in supporting and interconnecting components in the electronic products.With the increasing demand for thiner and multi functional electronic products,the qualities and properties of electrolytic copper foil that the market needs is higher.In this paper,three alloy plating process of Zn-Ni-Co was used to treat the rough surface of copper foil,which is 35?m thick.By working with different the parameters of each procedure of alloy plating,we could get copper foil which has excellent heat resistance and high bonding property on resin substrate.It is necessary to analyze and determine the basic technological parameters before treating the rough surface of copper foil.The factors such as pretreatment,additive type,electroplating process,main salt concentration,current density,plating time,temperature and anode plate were analyzed and the optimum basic technology was obtained.Through this process,the copper foil that we get has higher anti stripping strength,and the copper powder falling phenomenon also has greatly improved.The basic technological parameters will be used for the following study of heat resistant layer experiment.I studied the effects of Zn²⁺,Ni²⁺,Co²⁺ these three kinds of ion and current density on the anti stripping strength,instead of PS,the appearance,the metal content of the alloy layer of the copper foil in the system of potassium pyrophosphate.The results showed that the heat resistance of copperfoil was the best when chosing C?potassium pyrophosphate?:200g/L,C(Zn²⁺):8g/L,C(Ni²⁺):4g/L,C(Co²⁺):1g/L.First of all,five factors of potassium pyrophosphate,Co²⁺,Ni²⁺,Zn²⁺ and current of cathode were selected and four levels were determined to design orthogonal experiment,then tested the scanning electron microscopy?SEM?,the energy dispersive spectrum?EDS?,peel strength?PS?and the heat resistance test of copper foil samples.After analyzing the content of Ni,Co and Zn in alloy layer of the copper foil,We knew that the relationship between the Zn²⁺,Ni²⁺,Co²⁺,potassium pyrophosphate and metalcontent of alloy layer.Through testing the heat experiment on 16 sets of samples,we found that the eighth group to meet the requirements of heat resistance,whose colour did not change in 270? after heating for 120 minutes.Taking anti stripping strength as index,in order to make the most of the resistance to peel strength of the factors,the best combination was obtained.The best data is:C?potassium pyrophosphate?:200g/L,C(Zn²⁺):4g/L,C(Ni²⁺):8g/L,C(Co²⁺):4g/L.But the average value of the test results of anti stripping strength was 1.50,and the redictive value was 1.67313.Error was10.34%.The best combination of experimental samples were found to have obvious color change when conducting heat resistance experiments.Heat resistance was poor,so gave it up.Observation by scanning electron microscope before and after the alloy electroplating process of copper foil indicatesthat effect of alloy coating on peel strength of copper foil is not obvious.After that,two alloy plating process of Zn-Ni,Zn-Co,Ni-Co was used to treat the rough surface of copper foil under the sameprocess conditions,and test the heat resistance of the samples.The results showed that the heat resistance of the copper after plating processing by three elements was better than that by two elements.Above test results shows that although the effect of alloy layer of the copper foil on copper foil peel strength increase is not obvious,it can effectively enhance the heat resistance of copper foil.The best processdata is:C?potassium pyrophosphate?: 200g/L,C(Zn²⁺): 8g/L,C(Ni²⁺): 4g/L,C(Co²⁺): 1g/L,temperature:46⁵3?,current density: 5.5⁶.5A/dm2,time: 5s.Through optimal process,the colour of the copper foil thatwe get did not change in 270? after heating for 120 minutes,and peel strength is more than 1.5N/mm.We carried out the pilot project on the basisc of the existing surface treatment technology process and controlled conditions on the basis of Jiangxi Yates Copper foill limited liability company,and determined the technological process,material and conditions.Compared with the pilot project results,the experimental results can meet the stringent requirements of the industry.