Research On Prototyping Process Of Electronic Circuit On Flexible Substrate Based On Laser Induced

Flexible electronic circuits as an important component of flexible interconnection of electronic devices,are widely used in aerospace,wearable equipment,medical electronics and other fields.In view of the broad application prospects of flexible electronic circuits and the increasing market demand,it is of great value to develop a new green,fast,low-cost and batch production process for flexible electronic circuits.In this paper,a laser-inducing technology with high molding precision,fast selection processing and low-cost,easy-to-mass electroless metallization method are combined,and a new laser-induced flexible substrate surface electronic circuit forming process is proposed.In this study,polyimide films with excellent comprehensive properties were used as experimental substrates.The substrate is etched by femtosecond laser,and a large number of etched micropores are formed on the surface of the modified substrate.The roughness and hydrophilicity of the substrate are significantly improved,which provides a place for coating of activated liquid and adsorption of activated particles.The acidic activation solution composed of copper sulfate,sodium hypophosphite,sodium hexametaphosphate and lactic acid was coated on the modified substrates to form an activation liquid film.The film was induced by 450 nm blue laser irradiation.Activation before electroless copper plating was realized.After activation,a layer of catalytic active circuit pattern was formed on the surface of the matrix.The active component was detected to be copper particles.Finally,the electronic circuit on the surface of flexible materials was prepared by copper plating process.The process is selective activation by laser induction,avoiding the use of precious metals such as silver and palladium,and has the advantages of easy batch production,green and safe.It has good application prospects in the flexible electronic industry.The hydrophilicity of the matrix after acid-base treatment,plasma modification and femtosecond laser etching modification was tested by contact angle tester,and the best modification method of the matrix was selected according to the quality of copper plating.The modification process of femtosecond laser,the formula of activation solution and the parameters of laser activation were optimized by single factor analysis,and the proportion of additives in copper plating solution was optimized by comprehensive balance method.The activation reaction principle and coating quality were analyzed by means of scanning electron microscopy,energy dispersive spectrometer and X-ray diffraction.The electronic circuit was successfully fabricated on the surface of flexible polyimide film by the optimum process.The coating has clear outline,neat edges and angles,and resistivity is 3.6×10^-8?·m.The thermal cycling experiment shows that the coating has good adhesion.