Simulation And Experimental Research On Influencing Factors Of Trace And Ultra Trace Dispensing

With the rapid development of precision manufacturing,electronic packaging,and micro-electromechanical systems,the packaging and bonding technology of small parts is also constantly improving.In the field of micromechanics,the precision requirements for quantitative and fixed-point dispensing of fluid dispensing technology are also getting higher and higher,so the research on dispensing technology in trace(p L)and ultra-trace(fL)is of great significance.Aiming at the difficulty of realizing ultra-micro dispensing technology in the field of dispensing,this paper proposes an ultra-micro dispensing method for micro-scale manufacturing,which can realize the distribution of glue with micro-size features in the fL-pL range.By controlling the movement of the pipetting needle through the capillary tube containing the glue,the trace glue is attached to the pipette by means of adhesion,and then the adhesion between the glue and the dispensing surface and the effect of its own surface tension are used.Tiny glue drops are formed on the dispensing surface.In response to this dispensing mechanism,a fluid dynamics model was established for the fluid's rheological properties,force analysis,and geometric relationships,and the three main stages in the dispensing process were analyzed.Combine the FLUENT software to complete the dynamic numerical simulation of the dispensing process,simulate the effects of different pipette diameter,residence time,contact distance,glue viscosity and other parameters on the dispensing performance,and unpack the dispensing on different dispensing surfaces,The effect of different dispensing parameters on the spot diameter is revealed.Build an experimental platform based on the above research,first complete the single-factor experimental analysis of micro-dispensing,and design orthogonal experiments to determine the main influencing factors of glue spots;then,match the appropriate parameters on the basis of micro-dispensing for ultra-micro Dispensing for analysis,on this basis,through programming to control its trajectory,complete automatic dispensing.The experimental results show that during the dispensing process,the pipette diameter,residence time,movement speed,contact distance,glue viscosity,etc.all have an effect on the diameter of the glue spot,and the relative residence time and Movement speed is the main influencing factor.In ultra-micro dispensing,the diameter of the glue spot can be as small as 22.4?m,and the volume of the glue spot is 228 fL.Combined with the dispensing trajectory planning and control,the automatic and continuous dispensing process is realized,and the uniform fL-level dispensing array distribution of triangle and rectangular figures is completed.The method can realize ultra-fine precision dispensing with precise control of the size and position of the glue spot,the deviation of the glue spot diameter is within 2.2 ?m,and the deviation of the glue drop position is within 1.58 ?m.