Preparation And Properties Of Metal Based Functional Films On PPS Engineering Plastics By Magnetron Sputtering

As a plastic material in engineering field,Polyphenylene sulfide(PPS)has lots of exceptional properties,such as high strength,low creep,low water absorption,high elastic modulus and good flame retardancy,making it play an important role in environmental protection industry,automobile industry,electronic and electrical industry,etc.The metallized coating on the surface of PPS can endow it with the characteristics of electric conductivity,magnetic conductivity and aging resistance,which can not only meet the needs of some special occasions,but also have decorative properties,and broaden the application scope of PPS plastic.In this paper,Cr/Cu bilayer films and Cr/Cu/Cr trilayer films were prepared on the surface of PPS plastic plate by magnetron sputtering.The effects of different process parameters on the microstructure,conductivity and electromagnetic shielding of Cr/Cu films were studied,as well as the oxygenation of the two films in air.The results show that the increase of the sputtering current leads to the increase and the uniformities of the grain size.As the currents raise,the crystallinity first rises and then fall,achieving the best when the current is 1.2A;The films get denser;the thickness,conductivity,shielding effectiveness all improve with larger sputtering currents;After the current exceeds1.2A,the electromagnetic shielding effectiveness at all frequencies reaches above 50 d B.Extending sputtering time,the grains of the films get bigger,the size of the grains first get uniform and then dispersed;The crystallinity first rise and then fall by sputtering time,and show the best at 40min;when the sputtering time reaches 40 min,the density increases greatly;The thickness,conductivity,and electromagnetic shielding effectiveness all improve by adjusting to a lager time;By 50 min,the electromagnetic shielding effectiveness of the film is more than 53 d B at all frequencies.When the substrate bias is below 100 V,the change of grain size is not obvious;when the substrate bias is increased to 100 V,the grain size suddenly grows to 200nm;The film first become smooth and then rougher with the increase of substrate bias;the crystallinity and density keep enhancing with the increase of the substrate bias;The change of the thickness and the conductivity of all films seem to be not obvious under different substrate bias,the thickness reaches the minimum at 100 V and the conductivity is the best at 60V;the electromagnetic shielding effectiveness of the film is the best at 40 V and 100 V,reaching more than 50 d B at all frequencies.After 100 days in the air,the surface of Cr/Cu film was seriously oxidized and blackened,the content of oxygen increased from 0 to 9.5%,the conductivity decreased over time,and the sheet resistance increased by 150% after 100 days;Cr/Cu/Cr film still maintained good metallic luster after 100 days,the content of O increased to 4.26%,the conductivity decreased slightly with time,and the resistance increased by 1/3 after 100 days.It shows that Cr/Cu/Cr film has good oxidation resistance.The adhesion between the film and the substrate was characterized by the method of division,the results show that the film has good adhesion to the substrate.