Research On Electrical Properties Of Metallic Mesh

With the deepening of the understanding of the nature and characteristics of electromagnetic waves,more and more electronic devices have been widely used,which make the space electromagnetic environment increasingly complex,one problem is the electromagnetic wave intensity increase significantly,the other is application band widening of the electromagnetic wave,the corresponding,more and more people pay attention to electromagnetic shielding.A difficult and hot issue of electromagnetic shielding technology is electromagnetic shielding for the optical transparent components,in which metallic mesh structure can be used.However,the current study of metallic mesh mostly concentrated on conciliating contradictions of transmittance and shielding efficiency and advanced diffraction energy control,etc.As for the other important parameter of metallic mesh which is sheet resistance,there is no further research.This project will study sheet resistance in theoretical analysis and experimental research,the main research contents are as follows:In this paper,we first discuss the problem of poor probe contact and probe shifting during the measurement.By introducing the millimeter-sized intervening electrode the unreliable contact between the probe and the surface of metallic mesh are overcome,and in different intermediate electrode arrangement conditions,we analyzed the principle and designed experimental scheme of a variety of four-probe methods for sheet resistance measurement of metallic mesh including regular four probe method,dual electro-testing configuration four probe method,square four probe method,Van Der Pauw method,Rymazewski method,modified Van Der Pauw method and modified Rymazewski method;At the same time,in order to verify the validity of the four-probe method,an equivalent resistance method is proposed,in which the grid line in each cycle is equivalent to resistance.Based on Kirchhoff's law,the square resistance measurement formula is deduced and the measurement scheme is designed.Secondly,based on equivalent resistance method,we studied the relationship between sheet resistance and line width and period of metallic mesh.Metallic mesh consists of cross structure of multiple grid lines,and every structure corresponds to one sheet resistance value.The diversity of width and period of grid lines also influence sheet resistance of metallic mesh.Studying the change rule of sheet resistance with the mesh structure parameter change is helpful to obtain the desired sheet resistance value at the designing process.The relationship between sheet resistance and microwave shielding efficiency is also studied.The results show that sheet resistance and microwave shielding efficiency have the same optimized direction in the structure parameters of metallic mesh.Finally,considering the block-shaped intermediate electrode arrangement in a variety of four-probe method and a variety of mesh structure parameters,and also considering long strip-like intermediate electrode arrangement in a variety of mesh structure parameters of equivalent resistance method,the integrated mask of four-probe method and the integrated mask of equivalent resistance method are designed.The metallic mesh corresponding to the two integrated masks are fabricated by UV lithography.According to the measurement scheme the experiments are carried out,the experimental results show that the maximum standard uncertainty of the sheet resistance measurement is u=0.42?/ ?.Compared with equivalent resistance method,dual electro-testing configuration four probe method B,C mode,Van Der Pauw method and modified Van Der Pauw method are more accurate than other four-probe methods in measuring sheet resistance;dual electro-testing configuration four probe method B,C mode are not affected by the distance of probes,the intervening electrodes of Van Der Pauw method and modified Van Der Pauw method are located at the edge of mesh,which are more suitable for measuring sheet resistance of metallic mesh.