Study On Roughening Copper Surface By Chemical Template Method

Copper is a kind of metal material with a large scale of engineering application.In many studies,the surface modification of copper is often carried out by chemical etching and electrodeposition.After the surface modification process,it is suitable for further preparation of the electrode materials with large surface area,good catalytic activity and suitable for supercapacitors.Besides,according to the actual demand,the design of self-assembled monolayers is added to the rough substrate surface to modify its original structure,achieve the transformation of hydrophilicity/hydrophobicity,as well as the development and application of multiple-morphology,multi-level,high-performance micro/nano materials.In general,the copper surface coarsening process refers that the structure of copper is flexibly constructed by various surface modification methods.It is mainly an effective way to offer sufficient bonding force,enhance the materials’adhesion between multilayer circuit boards during the manufacturing process of electronic devices.The copper surface with a certain rough structure is characterized by glossmeter,SEM,contact angle test and open circuit potential method.In this thesis,the surface roughening process of pure copper is studied at the beginning.It is found that the sulfuric acid-copper chloride roughening solution can promote the formation of spherical particle rough structure on the copper surface.However,in formic acid-copper chloride roughening solution,the cuprous chloride film is densely covered on the copper surface with coarsening time more than60 s,which is not conducive to the growth of roughing structure.The subject aims to create effective chemical template methods for the preparation of rough copper surface,including replacement silver template method,silane template method and electroplating tin template method.The details are as follows:（1）In the replacement silver template method,the copper sample is immersed in silver ammonia solution.Under the conditions of 40°C～60°C and deposition time of 1200 s,the flocculent structure silver film is formed on the copper surface.And it is changed as spherical particle morphology in the sulfuric acid-sodium chloride roughening solution at 50°C after coarsening for 600 s.（2）In the silane template method,silane working solution is composed of silane coupling agent KH550 and a small amount of polyvinylpyrrolidone（PVP）.After silanization for 60 s at room temperature,the polymer film is formed on the copper plate.The PVP component is removed by alcohol washing to contribute the formation of the silane film with porous channels.In sulfuric acid-copper chloride-hydrogen peroxide coarsening system,rough copper surface appear with pore structure after coarsening for 120 s～600 s.（3）In the tin plating template method,according to the study of different process conditions,including current density,the amount of stannous sulfate,the bath temperature and the amount of hydrochloric acid,it is found that the electroplating tin solution with the best dispersion consist of 40 g/L stannous sulfate,120 m L/L sulfuric acid and 30 m L/L hydrochloric acid.When the bath temperature is 60°C,the current density is 12.5 A/dm~2 and the plating time is 10 s,the deposited tin layer is characterized by tetragonal crystal structure in XRD detection.The copper surface with tin template is corroded in alkaline and acid roughening systems,respectively.Furthermore,the acid roughening shows the advantages of the formation of orderly rough structure with clear growth direction.Meanwhile,adding polyethyleneimine to the coarsening system,with the assistance of the tin template,the roughening rate of the copper surface can be regulated and promote the formation of a ribbed bark structure with pores during the roughening of the copper surface.