Dynamic Performance Analysis And Experimental Study Of Non-contact Piezoelectric Micro-dispensing Valve

With the rapid development of microelectronics,there is an urgent demand for more precise,more accurate and faster adhesive materials dispensing technology in many occasions of microelectronic packaging.The traditional contact dispensing technology is hard to meet the current demand,so today,the research mainly focuses on the non-contact dispensing method with more obvious advantages.In order to meet the demand of high-speed micro-dispensing in microelectronic packaging,a kind of non-contact needle-typed jetting dispenser driven by piezoelectric actuator is proposed based on the principle of lever amplification.Based on the dynamic performance of the jetting dispenser,the research of the finite element model of the jetting dispenser,the analysis of the influence parameters of the dynamic performance of the needle,the development of the on-line detection device for the needle displacement,and the distribution effect experiment and test of the jetting dispenser are studied.The main content is as follows:A mathematical model and a finite element model of the multi-field coupling of jetting dispenser are established and the influence parameters of dynamic performance is simulated and analyzed.Firstly,the dynamic model of piezoelectricdriven jetting dispenser valve is established to analyze some parameters affecting the dynamic performance of the system.Then the finite element modeling of multi-field coupling is established.Based on the simulation analysis of the model,the natural frequencies of the jetting dispenser and the static output displacement of the piezostack model and the jetting dispenser at different voltages are obtained.The transient analysis results can better reflect the motion process of the jetting dispenser,and obtain the displacement curve of the needle of jetting dispenser under different parameters.Based on this,the factors affecting the dynamic performance of the needle are studied.Based on the Design Of Experiment method of two-level factor,the influence degree and influence trend of the performance parameters of the striker are analyzed.This subject selects eight parameters that affect the dynamic performance of the needle for two-level factor design.The obtained multi-group parameters are simulated by the finite element model of jetting dispensing,and the dynamic displacement curve of the needle under different parameters is obtained.Statistical analysis is carried out on the descending time and the downshift overshoot of the dynamic performance.The influence degree and influence trend of different influence parameters on the dynamic performance of the needle and the interaction between the factors were obtained.A new type of needle displacement on-line detection device that can be integrated into the jetting dispenser is developed.In order to detect the displacement state of the needle on-line,an on-line displacement detecting device integrated in the jetting dispenser is designed and the displacement detection accuracy and the displacement detection dynamic response test are performed.The test results show that the detection device can better detect the dynamic displacement of the needle.Moreover,the position of the nozzle with respect to the needle can be judged based on the amount of change in the output voltage signal,thereby it is able to judge whether or not the contact between the two ends or the degree of nozzle tightening.The experimental platform is set up to carry out the parameter verification of the dynamic performance of the needle and the dispensing experiment of adhesive materials is carried out.On the basis of the above research,the significant parameters affecting the dynamic response of the needle such as the voltage rise time,the voltage amplitude and the needle quality are experimentally verified.The experimental platform of the jetting dispenser distribution system is built to study the influence of the driving voltage parameters on the glue injection effect.Finally,the experimental analysis of the fluid dispensing under different needle positions is carried out,and the different stages of the nozzle position adjustment and the corresponding output voltage of sensor are obtained according to the displacement detecting device.This research will greatly lighten the workload of the jetting dispenser in the debugging process,and provide guidance for the nozzle debugging work of the piezoelectric micro-injection valve.