Simulation and experiment study on the jetting dispensing process driven by mechanical collision

Dispensing technology is widely applied in semiconductor packaging surface mount technology,LED packaging , where needs accurate flow control. The work efficiency of jetting dispensing is 5~6 times higher than the contact dispensing and the jetting dispensing with the better consistency of dispensing volume is the mainstream in dispensing technology in the future. The jetting dispensing process related needle high-speed acceleration movement and mechanism of droplets generation in complex coupling environment is always the key concerns of research in this field .In this paper, a two-dimensional axisymmetric model based on Volume of fluid (VOF) method is built by computational fluid dynamics(CFD) software .Fluent dynamic grid technique is introduced in numerical simulation to analyzed the fluid-solid coupling process .The mechanism of on-demand dispensing is analyzed by simulation results and the effects on droplet diameter caused by related parameters are summarized. Then the jetting dispensing experiment device and micro-jetting system is built based on the simulation experiment results. The experimental results closely matched with the theoretical simulation results indicate the method is feasible. The jetting dispensing technique could achieve the maximum frequency up to 200Hz within the dots consistency ± 10% in stability.