Research Of Fine Silver Patterning On Polyimide Films

Surface selective modification-repeated-ion-exchange-reduction method and in-situ selective ion-exchange self-metallization method are used in this paper to realize the fine silver pattern with high conductivity and high adhesion on the surface of the polyimide film.The experiment has studied the influencing factors of each step and determined the best preparation conditions in the surface selective modification-repetitive-ion-exchange-reduction method.Via FTIR,the effect of etching agents for different thickening systems on the molecular chain structure of the film was studied;SEM was used to observe the surface morphology of the silver pattern obtained in the experiment,and the relationship between the thickness,line width and resolution of the silver pattern and the etchant formulation and etching time was established,and the mechanism was also explored;the relationship between the kinds of silver salts,concentration of silver salts,ion-exchange time during ion-exchange process and the amount of silver loaded in the film was established by ICP;the surface resistance of the silver pattern was tested by a four-probe resistance meter,and the effect of repeated-ion-exchange-reduction times on the conductivity of the silver pattern was studied.Finally,fine silver patterned polyimide film with excellent conductivity(surface resistance<1?/sq)and low line width(<500 ?m),and excellent silver layer adhesion was received.In the in-situ selective ion-exchange self-metallization method,the experiment found that the thickening system has a huge influence on the performance of silver patterns and films.The silver patterned polyimide film obtained by the ion-exchange agent of glycerin/silver nitrate system has excellent conductivity and mechanical properties,but it has a large limit to the line width of the silver pattern;the ion-exchange agent of the thickening system A has a certain degree of damage to the mechanical strength of the polyimide matrix,but reasonable control of the silver ammonia concentration and ion-exchange time can reduce the impact to an acceptable level,and can obtain silver pattern with a very low line width(<300 ?m).