Mechanism And Experiment Study On Piezoelectric-gas Hybrid Driving Jet Dispensing

Along with the development of the electronic products miniaturization, intelligentdirection, surface-mount technology (SMT) and mixed assembly technique involve fluidcoating is also more and more. In microelectronic packaging, jet dispensing makes certainglue liquid to coat for electronic components fixed, coating, encapsulation on printed circuitboards. At present, contact dispensing technology already cannot satisfy the needs of themarket, The non-contact dispensing technology which has high efficiency, precisionaccuracy, good consistency, is gradually replace of contact dispensing technology.This thesis mainly content is put forward a new type piezoelectric hybrid gas jetdispensing device, using piezoelectric stack has the advantages of good responsecharacteristic and output characteristic, making the prototype, the drive mechanism and theeffect of dispensing experiment are researched. This gas mixer driven type piezoelectric jetdispensing device stem stroke is bigger, and can easily control the valve rod stroke, easily toadjust the glue dot size changes, so it’s wider applications in the microelectronics packaging;Because of the good dynamic response characteristics of the piezoelectric stack, highdispensing efficiency, structure simple.At first, in this paper, the characteristics of piezoelectric materials and theperformance of the piezoelectric stack were made related analysis and research. Thedisplacement characteristics of the PST150/5/100type piezoelectric stack wastested.Secondly, apply the FLUENT fluid simulation software to analyze the point glueinjection mechanism, it is concluded that the different viscosity liquid cement realize pointglue injection need to meet the different conditions. Detailed analysis the piezoelectric gashybrid control type injection point glue device’s working principle, and make the theoreticalanalysis and modeling simulation to the key components diaphragm spring of thedevice.This paper designed and manufacture a kind of piezoelectric type gas mixture controlinjection of dispensing device prototype by used piezoelectric stack as a driving source, andset up the glue dispensing experiment platform, introduced each subsystem of the injectionpoint glue prototypes; In this paper, the injection glue device designed has three units,piezoelectric driver unit, gas control unit and the injection unit, the design method of eachcomponent and the concrete implementation way were summarized in detail. Finally, through a lot of glue spraying experiment in this paper the research anddevelopment of piezoelectric and gas mixture control dispensing injection deviceperformance was tested. Get the related factors affecting the glue point at which a prototype,and analyses its reasons, provides a practical basis in order to further improve this devise.Glue dispensing test showed that the point glue dispensing accuracy of the device aremainly affected by the glue solution cavities and the pressure differential between thepressure chamber, and the size of the On-Time, and driving voltage of the piezoelectricstack. The thesis choose the electronic encapsulation using silica gel as a glue solutioninjection experiments. The experiment measured the design and produce of piezoelectric gashybrid type jet dispensing mechanism, injecting for the biggest glue solution viscosity canreach3000cps, glue point minimum diameter is about0.6mm, minimum quality is1.2mg,maximum dispensing frequency up to80Hz, and glue point quality consistency error atwithin5%.