Research On Electromagnetic Reliability Of Flexible Electronic Interconnect Structure

Flexible interconnect structure is the key for normal operation of flexible electronic systems.It not only has the high performance and the high reliability of traditional electronics,but also has an excellent flexibility and a stretchable mechanical flexibility.Therefore,research on flexible interconnect structures is desired and necessary.At present,the research of flexible interconnect structures mainly focuses on structural designing,material preparation and mechanical performance analysis.There are rare studies on the electrical performance effects of high frequency,deformation and fractal forms.For the miniaturization of functional components of electronic circuits,the increase in system integration density and operating frequency,the electromagnetic reliability of the structure becomes more and more significant.It is of great significance to analyze the electromagnetic reliability of flexible interconnect structure.Focusing on the electromagnetic reliability of flexible interconnect structures,our work has been completed as follow:(1)Modeling flexible interconnect structures based on basic concepts of fractal theory,and the 3D electromagnetic simulation software HFSS is used to complete the simulation and analysis of the fractal flexible interconnect structure in the frequency range of 0.01-40 GHz.The effects of single physical variables such as line spacing,line width,line length,substrate thickness,and substrate material on the return loss and insertion loss of the flexible interconnect structure are studied,and the optimal parameters of the flexible interconnect structure are obtained.Then,the flexible interconnect structures with different bending radius are simulated and analyzed,and the influence of different bending amplitudes on the transmission characteristics of the flexible interconnect structures is studied.Finally,experimental measurements are performed on flexible interconnect structures with different lengths,and the measured and simulated results are compared and analyzed.(2)The transmission characteristics of flexible interconnect structures with different fractal parameters are studied.Modeling and simulation of flexible interconnect structures with different number of U-shape units,different number of fractal orders,and different polyline shapes are performed and the effects of the number of U-shape units,fractal orders and polyline shapes on the return loss and insertion loss of the flexible interconnect structure are compared and analyzed.Then the structures are measured experimentally,and the influences of bending and twisting deformation on the electromagnetic characteristics of flexible interconnect structures are analyzed.(3)Multi-angle studies on signal integrity of flexible interconnect structures are performed.First,eye diagram simulation is performed on the flexible interconnect structure to study the time domain signal integrity of the structure.The communication links in ADS are established,and eye diagram simulations under the different conditions of line length,the number of U-shape unit,fractal order,the bending radius,and the signal frequency are completed,the signal transmission qualities of different communication links are analyzed,and the simulation results are used to determine the effect of line length,deformation,and operating frequency on the eye diagram.Then skin surface performance tests are performed to analyze the signal integrity problem under the interference of human physiological parameters.Finally,the flexible interconnect structure is applied to wireless temperature acquisition system to verify the reliability of the signal transmission application of the flexible interconnect structure.