Research And Production Of Anti-Silver Paste Diffusion Agent

The conductive silver adhesives is a chip adhesive which used in the lead frame of the electronic packaging industry.It has excellent conductivity,good linear resolution,simple operation,non-toxic and non-pollution,and has been widely used in the field of microelectronics packaging and electronic packaging.When use conductive silver adhesives,due to the high surface roughness of the silvered surface,or the residue of oil,other protective agents or additives.It is often found that the epoxy resin in conductive silver adhesives bleed out(epoxy bleed out,EBO).Epoxy resin spreads along the surface of the substrate,forming white or yellowish-white marks,resulting in poor welding or functional defects,and even failure of welding lines.In order to solve this problem,the common method is to wash the surface to remove contaminants,Or reduce the surface roughness of the coating,Or strengthen supervision to prevent the surface contamination of the substrate,but may damage the anti-discoloration effect and sealing effect,affect the bonding strength of the chip.and this method is cumbersome and demanding;Therefore,It is imperative to develop a new anti-silver adhesive diffusion method.This study developed a silver spread glue remover,prevent conductive silver glue was prepared in lead frame and IC chip bonding diffusion reagent,and determine the process parameters,in preparation of silver coating a layer of hydrophobic membrane,and test its performance;The mechanism and film forming mechanism of anti-silver adhesive diffusion were discussed,which laid a certain theoretical foundation for the development of serialized products and large-scale application of factories.The main research contents are as follows:(1)Based on the preliminary screening,single factor experiment and orthogonal experiment,the composition and content of the basic solution of the anti-silver glue diffuser are determined.With the visual method,the main forming agent and the auxiliary forming agent were selected through the surface hydrophobic condition of the silver plate.The basic composition of anti-silver diffusion agent was determined.(2)Process optimization by control variable method,including p H,temperature,time,etc.(3)The best technology of anti-silver glue dispersant was as follows: 370mg/L KH550,280mg/L polyether modified silicone oil,50mg/L Tetrabutyl ammonium Chloride,8mg/L sulfhydryl heterocyclic compound;PH 6.0 to 7.0,20 to 30 temperature,immersion time: 30 ?to 40 s.(4)By contact Angle test,bonding strength testing,contact resistance testing and silver glue seepage resistance(EBO)resistant evaluation,verify the performance of silver spread glue remover,apparent morphology of the coatings was tested by sem,EDS and ir test the element composition and valence state of film layer;(5)According to the test results,the anti-diffusion mechanism and film forming mechanism of the anti-silver glue diffusion film layer were preliminarily discussed.