Study On The Mechanism And System Of Micro Spray Of Rubber Drop Driven By Piezoelectric Actuator

In the field of microelectronic packaging technology,high-speed micro spray has become the focus of research in recent years.The rapid,micro and accurate distribution of glue drops have become the target demand of this field.There are many kinds of colloids which have different characteristics,especially the high viscosity colloids.Due to high viscosity of the liquid,its separation has been a difficult problem in the industry.Therefore,the study of rapid and accurate separation of colloids has a very special significance.In this paper,for the demand of microelectronic packaging field,and the distribution problem of high viscosity colloid,a kind of micro spray valve which is driven by a diamond-type micro-displacement amplifier and impact needle are designed based on the piezoelectric actuator.The micro spray valve has a large driving force,and combines the advantages of piezoelectric actuator,such as rapid response and accurate output displacement.The diamond-type micro-displacement amplifier has a compact structure and rapid recovery,which can realize the distribution of high viscosity colloid.As the characteristics of the rapid micro distribution of droplets in the micro spray valve,this paper focuses on the separation of liquid,the design of the diamond-type micro-displacement amplifier based on piezoelectric actuator,and the analysis of dynamic characteristics of piezoelectric driven impact pin micro spray device and the design and experiment of droplet micro spray system.Firstly,in order to analyze the principle of droplet micro spray,this paper studies the process of separation of the single droplet.Based on the modeling software which called Gambit,the striker nozzle model is established,and then the finite element analysis software which called Fluent is used to figure out the simulation.When the driving pressure,liquid viscosity,striker displacement,and nozzle diameter in the process of micro injection are changed,the specific impact of single parameter or combination of different parameters on the separation and distribution volume of the droplets are studied,which will be a provide guidance for the following experimental research and the design of micro injection valve system.Then,due to the advantages of piezoelectric actuator,a diamond-type micro-displacement amplifier is proposed.The displacement magnification and the first-order natural frequency of the amplifier are calculated theoretically.Different mechanisms are designed according to the structural parameters of the diamond-type micro-displacement amplifier itself,and then the finite element software Abaqus is used to analyze each node of the diamond-type micro-displacement amplifier.The influence of structural parameters on the magnification and the first-order natural frequency is obtained.Finally,based on the results of the finite element simulation analysis,different diamond-type micro-displacement amplifiers with different processing parameters are designed.The regular characteristics of the diamond-type micro-displacement amplifier are verified by the control experiments.The next step is to study the mechanical structure and micro injection principle of the needle-type micro-liquid jetting system.In this paper,the theoretical mathematical model of diamond micro displacement amplification mechanism,piezoelectricity actuator,needle,nozzle and so on is established,and the working process of the system is calculated,the stress distribution of each mechanical structure in the spray process is studied,and the specific influence of each mechanical structure on the final needle's displacement is calculated.Finally,based on the above research,a high-speed micro spray system is designed,which includes the needle-type micro-liquid jetting system,micro spray valve driving module,three-axis motion platform and control module of the system.The injection of different viscosity liquid,especially high viscosity liquid in the system is studied,the basic experimental test,demonstrate the feasibility of the drop dropping and diamond-type micro-displacement amplifier studied in the early stage are figured out,and the viscosity oriented distribution accuracy experiment to verify the feasibility of the system in the field of microelectronics packaging is done.