Preparation Of High Density Spherical Copper Powder For Copper Conductor Paste

More electrodes of the electronic element and gold?silver and other precious metals as raw materials,but with the recent fluctuations in precious metal prices as the world's political and economic situation and soaring.Therefore,from an economic point of view,with base metal electrodes instead of the precious metal to make efforts to become the target of people.Copper has excellent electrical conductivity?thermal conductivity,and its price is much lower than the precious metals gold and silver,thus gradually become a focus for researchers.Copper paste gradually replaced in many areas,such as precious metals silver paste is the inevitable trend of future development,and copper as a main component of copper paste,copper conductor paste was prepared in line with the application of ultra-fine copper powder is a key step in the preparation of copper paste.This paper describes the mechanism of ultrafine copper powder preparation,and through the study of the microelectronics industry while copper key technologies,address key issues affecting the performance of copper and copper paste,preparation of ultrafine copper powder and its preparation process copper pulp slurry for copper and industrialization.Conductive copper paste film after high conductivity and density and other key technical indicators are made of ultra-fine copper powder performance decision.The morphology and structure of ultra-fine copper itself,the particle size distribution determines the overall performance.The conductive copper paste performance requirements for ultra-fine copper powder,preparation of ultrafine copper powder morphology required to meet the spherical of spheroidal,controlled particle size range between 1?3um and relatively concentrated distribution,and requirements while achieving high density.In this thesis,a study of the formation mechanism of ultrafine copper powder and superfine copper powder applied to the copper conductor paste with the preparation and performance.And to explore the glass powder,organic carrier such as copper paste composition of the preparation process and formula.(1)To study the mechanism of liquid preparaed by ultrafine copper powder,ultrafine copper powder thus obtained theoretical maximum density of 6.643g/cm3.Best preparation process morphology,particle size control mechanism formed by the same process for preparing high-density spherical powders obtained copper powder.(2)By comparing the ammonia complex,technical preparation and properties of ultrafine copper powder and potassium borohydride reduction step reduction of hydrazine hydrate.Preparation drawn copper conductor paste of high-density spherical copper.(3)Through process optimization experiments,After testing to get the optimum conditions:concentration of reactants copper sulphate 1.4mol/L;sodium hydroxide 8.6/L;pre-reducing glucose 1.2mol/L;proportion of hydrazine hydrate was added stepwise 5:4,the first step in adding a temperature of 50?,the second step in adding a temperature of 60 ?;a small amount of dispersant polyvinylpyrrolidone;and it is the best way to add pre-reduction and before adding a second before adding hydrazine hydrate while.Studies have shown that:the key factor in the reaction temperature?reducing agent,reducing the concentration of the dispersant and the way the reactants are added impact of ultrafine copper properties.(4)The better sphericity cuprous oxide copper powder generated by spherical degree,the better,the greater the density and the smaller the particle size;Reaction system at set to 50,60 ? temperature better powder morphology and density;By vacuum freeze drying of copper powder dispersion is best.(5)Copper film prepared by the performance test results:Adhesion to 19N/mm2;Sheet resistance of 0.9m?/?;The weldability are good performance,which can be achieved using the conductive paste of the microelectronics industry requirements.