Printing Regularity And Process Optimization Of Electrohydrodynamic Jet Printing For Micro-patterning

Electrohydrodynamic Jet printing(E-jet printing)is an emerging and promising micro/nano scale 3D printing technology in recent years based on the Additive Manufacturing(AM)principle to fabricate micro nanostructures or functional products,which has the advantages of high precision,wide printing material,low cost,simple structure,especially for high viscosity liquid material,It has the unique advantage which the print resolution can reach an order of magnitude lower than the nozzle size.Moreover it has shown wide application prospects in many fields.However,the forming mechanism of E-jet printing is more complex and has many influencing factors.At present,the research on E-jet printing is not thorough at home and abroad,revealing the internal rules of printing,obtaining the ideal printing process window,realizing high precision micro patterning of various functional materials on the substrate of different materials to meet the application requirements in various fields is still the key issue of electrohydrodynamic jet printing.This paper focuses on three aspects of theoretical analysis,experimental research on optimization technology and micro patterned case study,a systematic theoretical analysis and experimental study on two typical materials for influence of process parameters and printing process window of E-jet printing are carried out;and the correctness and feasibility of the printing law and process optimization window are verified through micro patterning with 3 different types of printing materials and high precision 3 different material substrates.The specific work is as follows:(1)Based on the basic theory of electro hydraulic dynamics,this paper systematically analyzes the jet mechanism of jet printing in two aspects: the cone-jet injection mode and the influence factors of the cone-jet.(2)On the basis of theoretical analysis,the specific experimental study of printing polymer materials is studied from three aspects of the UV ink preparation,the influence of process parameters and rules and the optimization of printing process window.The influences and rules of the electrohydrodynamic jet printing process parameters on Taylor cone and printed patterns are revealed and the ideal jet printing process window for the same nozzle is optimized,the pattern of minimum line width 3?m is printed by the UV curable polymer(4200cps)with the nozzle diameter of 60?m.In addition,this paper proposes a method which can govern the printing accuracy and quality of printed patterns by controlling the shape and size of the Taylor cone with adjusting the process parameters.The proposed method and experimental results lay the foundation for improving printing precision,quality and print stability of electrohydrodynamic jet printing.(3)In view of the application requirements of ultra fine conductive circuits(electrodes)for printed electronics,3D structures,electronics and high precision electronic devices,the printing law of nano silver conductive ink material with wide application prospect is studied,and the printing process window suitable for different material substrate is optimized.the pattern of minimum line width below 5?m is printed by the high viscosity(9500cps)nano silver paste in PET,glass,silicon substrate with the nozzle diameter of 60?m,and through the sintering and the electrical resistivity,the minimum resistivity of 6.54??·cm.(4)The cases study of micro patterning of E-jet printing is carried out.Through micro patterned with 3 different types of printing materials(photosensitive polymer,high viscosity nano conductive silver paste,high content of nano silver conductive ink)and 3 kinds of different material substrate(PET,silicon,glass),the 6?m width silver wires are printed by the high silver content high viscosity(-20000cps)nano conductive paste on silicon substrate and the silver grid transparent electrode is printed by high viscosity nano conductive silver paste on the PET substrate(3?m width)and the glass substrate(8?m width)with the nozzle diameter of 60?m,and the correctness and feasibility of the influence of the process optimization and the printing process window are verified.