Device and technique for high-viscous adhesive micro-dispensing with electrostatic induction

To solve the problem of high-viscous adhesive micro-dispensing for micro-assemblies, the technology and equipment of electrostatic loading and force feedback are presented. With finite element modeling simulations, the influences of factors such as the initial height of the transfer head from the adhesive surface and current on the adhesive droplet-loading and transferring process were analyzed. The main specifications and key components for the dispensing process were determined, and the complete micro-dispensing process was constructed. Moreover, both the hardware framework and control software for the prototype machine were developed. Finally, micro-dispensing experiments for epoxy resin adhesive were performed to verify the performance of the device. Experimental results show that the volume and radius of the loading and transferring droplet can be controlled by the initial height and threshold current that trigger the breakup of the liquid bridge. The radius and volume of the transferred droplet can be controlled in the range of 96-193 μm and 0.43-2.81 nL, respectively. The consistency error of the final-transferred droplet is 4%. The novel method and device can significantly improve the performance of high-viscous adhesive micro-dispensing. © 2021, Science Press. All right reserved.