Design And Performance Analysis Of Interconnect Based On Stretchable And Flexible Substrate

As an emerging electronic technology,flexible electronics is of revolutionary significance to product development,and has attracted great attention from academia,industry and government.As the basic component of flexible electronic devices,interconnection wires are an important index for judging the tensile performance of the device.Therefore,this thesis is based on the finite element to optimize the design and performance analysis of the wire.At the same time,the stencil printing method is innovatively used to prepare the stretchable interconnection wire and apply it to the flexible sensor.The main contents are as follows:(1)The low-cost,high-conductivity copper was used as the interconnection wire material,and the flexible substrate was Ecoflex00-30 silicone rubber with excellent tensile properties.Through uniaxial tensile test,it was determined that Ogden is the constitutive model of silicone rubber and obtained the material parameters:₁=1.120)^-2?₁=2.82?₂=3.360)^-8?₂=11?₃=2.990)^-2?₃=-3.11.(2)Four interconnecting wires of sine,rectangular,U-shaped,and horseshoe-shaped structures were designed.First,ABAQUS was used to simulate the stress distribution of the wires under multiple stretch rates(2%-5%).The results showed that the maximum stress values of the horseshoe-shaped is the lowest.Then,four kinds of interconnection wires were prepared by stencil printing method,and their tensile properties were tested.It is observed that the stress concentration areas of the sinusoidal,rectangular and U-shaped structures under 4%elongation rate showed different degrees of fracture,while the horseshoe-shaped surface was intact.Afterwards,the electrical performance test was carried out.According to the resistance surge point,the elongation rates of four structures were 3%,4%,6%,9%,respectively.From the synthesis of simulation and experiment,it was concluded that the horseshoe-shaped interconnection wire has the best stretchability compared to the other three structures.(3)The influence of the shape and material of the horseshoe-shaped interconnection wire and the flexible substrate on the pre-tension capacity of the wire was simulated.The results showed that the wire's ability to withstand pre-tension is positively correlated with the radius,angle,and material's elastic modulus,and negatively correlated with the wire width and thickness.When the thickness of the flexible substrate is much greater than the thickness of the interconnection wire,the ability of the wire to withstand pre-tension is not affected.In addition,the smaller the elastic modulus of the substrate,the greater the maximum pre-tension that the wire can withstand.Based on comprehensive considerations,it is found that 14%pre-tension has the best effect on the horseshoe-shaped interconnection wire.(4)The effects of pre-tension,drying time,the shape and material of the horseshoe-shaped interconnection wire and the flexible substrate on the stretchability of the wire were studied respectively.The results showed that the drying time(15-60min)can effectively increase the elongation rate(4%-9%)of the wire.After applying a 14%pre-tension to the substrate,the elongation rate of the interconnection wire increased from 9%to 20%under a drying time of 60 minutes.In addition,the key parameters of the horseshoe-shaped interconnection wire and the flexible substrate have the same influence on the wire elongation as the wire withstands the pre-tension ability.(5)The electrical properties of the horseshoe-shaped interconnection wire under tension,bending and twisting are tested,and it is found that it has good anti-interference performance.The fatigue test of the horseshoe-shaped interconnecting wire using a tensile testing machine shows that its tensile resistance is good.Combining the wire with a self-powered tactile sensor based on the principle of frictional electrification,the output voltage of the sensor is stable at about 13.0 V under different bending angles.The experimental results show that the horseshoe-shaped interconnection wire can effectively reduce the influence of sensor deformation on the output signal and improve the stability of the sensor.