Study On Inkjet Printing Silver Electrodes And Effects Of Post-treatments On Its Performance

As a non-contacting,environmental friendly and direct patterning film deposition technology,inkjet printing can dramatically reduce the cost and simplify the process steps so that it attracts extensive attention in the application of electronic devices.However,the problems such as complicated process steps,high material cost and long process time exist in the traditional manufacture technology like photolithography and sputtering.Thus,inkjet printing electrode technique is found to be a promising alternative technology.In this paper,in order to figure out the mechanisms how inkjet printing process and post treatment affect the fabrication of silver electrode,the effects of inkjet printing process and post treatment of silver electrode on its patterning quality and performance have been analyzed by adjusting the technological parameters.Finally,the control of the performance of inkjet-printed silver electrode could be realized,and good overall performance of silver electrode could be attained in relatively low process temperature.In this paper,nanoparticle silver ink and metal-organic-decomposition silver ink were used as the main material.Firstly,the effects of different inkjet printing parameters on the patterning quality were studied,and then the silver electrode with good patterning quality was fabricated by optimizing the process parameters.Then,the mechanisms of UV curing and traditional heat curing affecting surface roughness,conductivity,adhesion strength and mechanical stability of inkjet-printed silver film were studied in this paper so that silver electrode with good overall performance could be fabricated.As for surface roughness,UV-cured silver electrode exhibits good smoothness,of which the lowest surface roughness was 1.3 nm and could meet the demand of multilayers film devices.Besides,UV precuring was used to reduce the surface roughness of heat-cured silver electrode in this paper.As for conductivity,longer curing time,properly higher temperature or shorter distance between samples and UV light source could promote the removal of organics and the merging of silver particles so that better conductivity could be acquired.As for adhesion strength,the content of organic residues and the contacting area between silver film and substrate could be controlled by tuning post treatment so that the adhesion strength could be enhanced.As for mechanical stability,it could be improved by adjusting post treatment which could control the content of organic residues and the merging of silver particles to enhance the bond between particles.Finally,this paper systematically analyzed and summarized the mechanisms of inkjet printing parameters and two kinds of post treatment affecting inkjet-printed silver electrode.Besides,the NP silver electrode with resistivity of 6.8×10^-8Ω·m,adhesion strength of 4⁵B and the MOD silver electrode with resistivity of 4.6×10^-8Ω·m,adhesion strength of 4⁵B were fabricated in relatively low temperature,and both had good mechanical stability.This paper provided a reference for the low-temperature fabrication of inkjet printing electronic devices in the future.