Fundamental Research On Digital Micro-injection Technology Applied To Circuit Board Packaging

Digital micro jet is a kind of micron-scale augmented material manufacturing technology which has been developed rapidly in recent years.It has been widely used in micro-structure manufacturing,biomedicine,microfluidic device manufacturing,microelectronic packaging and other manufacturing fields because of its advantages of diverse forming materials and high precision.At present,there are many shortcomings in traditional PCB packaging methods,such as waste of materials,low automation level,high casting cost and poor precision.So this paper introduces digital micro-spraying technology into the field of PCB packaging,proposes a PCB packaging method based on digital micro-spraying technology,and independently develops and designs a digital micro-spraying system for PCB packaging.The packaging system and forming process of micro-sprayed circuit board were studied.Finally,the stability of the equipment and the feasibility of the proposed method were verified by experiment,which provided a new idea for circuit board packaging.Firstly,the working principle and molding mechanism of digital micro jet are studied,which provides theoretical guidance for the construction of simulation and experimental systems.From the theory of fluid mechanics,the droplet ejection type is introduced,and the digital micro jet technology suitable for this subject is selected according to its different driving methods.Secondly,the process of micro droplet jet is simulated,On the basis of the mathematical model,the finite element simulation software COMSOL is used to simulate the flow field and velocity field in the process of micro droplet generation by using the laminar two-phase flow-level set model to obtain the liquid properties and the jetting speed on the droplet forming effect,The influence law of the droplet forming effect can provide guidance for the selection of the subsequent spray materials,and analyzes and summarizes the conditions of generating satellite droplets and the formation conditions of good micro droplets.Then on the basis of theoretical analysis and simulation,the digital micro jet molding system is designed independently.The system includes:mechanical structure,motion control system,main control module,air pressure,temperature control module,etc.This paper elaborates on the design idea of the digital micro jet package printing system and finally completes the assembly and debugging of the test system.Finally,the packaging experiment of PCB is carried out on the experimental platform,and the packaging defects under different process parameters are discussed.The quality and precision of PCB packaging are analyzed.The application of digital micro jet 3D printing in the field of PCB packaging is realized,which promotes the development of PCB packaging technology.