Mould Design And Process Optimization Of Gel-casting For Alumina Ceramic Substrate

The vigorous development of electronic packaging industry requires high quality and reliable packaging substrate materials.Among them,alumina ceramic substrate has a good performance in general application.However,the preparation process of alumina ceramic substrate still needs to be improved continuously,and the requirements for the area,size accuracy,and performance stability of the alumina ceramic substrate are getting higher and higher.With the further development of gel-casting technology and industry of alumina ceramic substrate,the traditional grouting slurry filling process only has the weight and fluidity of slurry,but the process parameters are less controllable and can not meet the requirements of mechanization and automation for the production of alumina ceramic substrate,need to improve molding process.Mold design is an important part of continuous improvement in the process of gel-casting of alumina ceramic substrates.The quality of product quality,production efficiency and cost are directly affected by the design of injection slurry mold system,so it is particularly important to study the design and optimization of gel-casting mold.In this paper,the design and process optimization of gel-casting mold for alumina ceramic substrate is the main research object.Based on the study of the rheological properties of alumina cement slurry,the computer aided simulation technology was used as the aid.The influence of mold structure on the filling process of alumina slurry was analyzed qualitatively.The mold parameters were optimized based on orthogonal experiment,and the optimized mould was verified by the process.Firstly,the effects of solid content,dosage of dispersant and milling time on the rheological properties of the slurry were discussed.The optimum proportioning scheme with solid content of 54.57 vol% was determined.The optimum preparation parameters of the slurry were the dosage of dispersant at 2.0 wt% and the ball milling time 18~30 hours.Secondly,the three-dimensional modeling software was used to model the pre-formed sheet.The influence of different mold gate structures on the filling process of the slurry was analyzed by using the mainstream finite element flow analysis software.The effects of different gate structures on filling time,maximum shear rate,cavitation and velocity are discussed.Finally,the parameters of the casting system of alumina ceramic gel-casting mold based on orthogonal experiment were optimized and the cavity shape was improved.A kind of gel-casting molding equipment for alumina ceramic substrate with good processcontrollability is introduced.The optimized mold design is used respectively to optimize the front and back molds and forming processes,and to verify and contrast the production processes.Through the research of this paper and the combination of computer aided technology,the design and optimization of gel-casting mold for alumina ceramic substrate have been completed.With the optimization of equipment,large size alumina ceramic substrate has been prepared,which is 0.2% lower than that of the traditional molding process.