压电驱动液压放大式喷射系统

Piezoelectric driven hydraulic amplification jetting system

为了实现高速度高精度的非接触喷射式点胶,设计了一种压电驱动液压放大式喷射系统。该系统采用压电叠堆作为驱动源,基于液压放大原理放大压电叠堆的输出位移来实现胶液的喷射。对液压放大单元进行了理论分析,并结合压电叠堆的输出位移对液压放大单元进行了参数化设计;然后,利用激光测微仪分别测量了撞针和压电叠堆的位移,得到了液压放大单元在不同电压下的输出位移。最后,搭建了喷射系统实验平台,选用黏度为1 000cps的环氧树脂进行点胶性能测试,得到了驱动电压和高低电平时间对胶点体积的影响规律。实验显示,该喷射系统可稳定地实现每秒喷射143个胶点,胶点的体积误差可控制在±3.11%以内,是适用于电子封装行业的高效、高精度点胶方法。

To pursue a more accurate non-contact dispensing in a higher speed, a piezoelectric-driven hydraulic amplification jetting system is designed. The system uses a piezostack as the driving source and amplifies the output displacement of piezostack based on the hydraulic amplifier principle to implement the jet glue. Through theoretical analysis of hydraulic amplification module, the structure parameters of the module are designed by combining with the analysis of output displacement of the piezostack. Then, the displacements of the needle and the piezostack are measured by a laser micrometer, and the magnifications of the hydraulic amplifier module on different voltages are obtained. Finally, a jetting system platform is set up, the epoxy with a viscosity of 1 000 cps is chosen to check its property of dispensing, and the relations between the driving voltage, high-low voltage time and the volume of droplet are obtained. The experiments show that the jetting system can stably jet 143 glue dots per second and the volume error of each dot is within ±3. 11%, which is a more efficient and accurate dispensing method for the electronic packaging.