Research On The Performance Of Pneumatic Jetting Valve In The Dispensing Of High-performance LED Package

:High-performance LED has good comprehensive performance and usability.So it has been recognized as the next generation of lighting source technology.The product quality of high-performance of LED depends largely on the quality of the chip packaging.In the dispensing process of high-performance LED package,because of its high efficiency,stability, consistencyjetting dispensing technology will become the mainstream of the dispensing process.At present,in the LED jetting dispensing also exists difficulties in dispensing and poor consistency, and the primary obstacles that hinder us from resloving the two hard challenges are the lacks of understandings of jetting dispensing process and craft and the performance of existing pneumatic jetting dispensing equipment.Researches on the effect of the different factors on the dispensing performance is good for gaining understanding to the process of dispensing,enhancing the quality of dispensing process and guiding the design of packaging equipments.This paper first outlined the development of the high-performance LED lighting technology and introduced the current mainstream dispensing technology in electronic packaging industry, according to the high-performance of LED package requirements,the paper contrasted different dispensing technology and explained the working principle and the existing questions and challenges of mechanical type of dispensing valve; then from the high-performance LED dispensing materials,this article analysed the phosphor concentration, liquid temperature, shear rate, placed time affecting on viscosity properties of LED phosphor silicone materials by using rotary rheometer,and obtained the basic pattern of the viscosity of LED materials;then the paper using the differential equations of motion of multidimensional viscous fluid and the materials features obtained above,and combined with the actual high-performance LED packaging conditions,using the finite element simulation of Flow3D established model of dispensing process,and based on the model,this paper reveals glue jetting dispensing process, discovered the phenomenon of the injection flow of glue and so on.Then the paper analyzed the nozzle length, glue providing position, the base cavity cone angle, needle cavity affecting on injection speed of glue, glue quantity and back flow quantity; finally based on the the analysis results of finite element simulation,and the high-speed camera system and actual LED dispensing experiments,the paper analysed the effcets of temperature,stroke,pressure and other working parameters on the performance of dispensing process.77pictures,3tables and66references.