Fabrication Of Flexible Conductive Pattern By Magnetic Field Pattern And Volume Additive Process

Flexible electronic has attracted great attention in academically and in industry for its huge potential in application.Flexible conductive pattern named as Flexible Printed Circuit(FPC).For its thin thickness,good softness,flexible feature,light weight,it can work normally in the condition of bending deformation and tensile deformation,therefore,it has potential in the application flexible electronic.The fabrication of flexible electronic circuits is the key technology of flexible electronics.How to prepare flexible circuits conveniently,efficiently,environment friendly is an important issue in the field of flexible electronics.This study presents a new technology to the preparation of flexible circuits.By combining the technology of magnetic field patterning and the volume addition,flexible conductive pattern could be facilely prepared.Through magnetic field force driving metal nanoparticles with magnetism to form a setted pattern,then he particles fusing together by displacement reaction in situ,the pattern become compact and the conductivity of the metal pattern was achieved.The principle of magnetic field pattern is the magnetic metal particles could be self-assembled into a pattern which is the same with the magnetic template made of magnetic response materials a magnetic field.Magnetic field pattern is attracted wide attention for the advantage of energy saving and simple process and high efficiency.However,the pattern composed with particles is not conductive for there is gap between particles.To achieving the conductivity of the metal pattern,we took advantage of volume addition process to make particles fusing into a continuous metal circuit.Volume additive process is a phenomenon that the volume increase of product compared with reactant's volume,taking place in situ-galvanic displacement reaction.In situ-galvanic displacement reaction of volume additive effect proceeds between the metal with high valence and small size and the metal with low valence but big size.With the displacement reaction,not only the product's number of atom increases and the volume increases,but also the particles grows into a continuous one.By this way,the contact between particles increase greatly,which causes the conductivity metal pattern.Iron nanoparticles has the capabilities of magnetic response and reacting with silver kation with volume additive process.Thus,we can adopt magnetic field trapping technique and volume additive process by iron nanoparticles to create a facile,environment friendly,energy saving method to prepare flexible conductive pattern.This research could be divided into two parts.In first part,we focused on the simulation of magnetic field by COMSOL Multiphysics software and the analysis of magnetic force driving iron nanoparticles motion to establish mechanism of magnetic field trapping technique.In second part,we prepared iron nanoparticles though FeCl3·6H2O and NaBH4,Then we prepared iron nanoparticles' pattern by magnetic trapping technique.At last,the iron nanoparticles' pattern was turned into a conductive silver's pattern.Though three steps,we fabricated the flexible conductive pattern successfully.The electric conductivity of flexible conductive pattern with 300?m width,6cm length in this study can reach 1.2×106 S/m in total bend condition.It indicated that the good conductivity and huge potential of this study in applied to flexible electronic industry.