电子组装喷射点胶过程流体特性CFD模拟分析

喷射点胶技术是电子组装的核心技术,针对如何喷射小直径胶点以满足微电子封装要求这一问题。文中基于气压驱动点胶阀的工作原理,建立顶针和喷嘴碰撞结构二维几何模型,采用CFD计算机流体动力学分析软件对点胶过程中喷嘴口胶水喷射速度、密闭内腔胶水液压进行仿真模拟分析。数值仿真结果表明,顶针几何外形、顶针运动行程及喷嘴张角是影响胶水喷射速度的主要因素,喷射胶点的直径大小是由这些影响因素决定的。

CFD Analysis of Fluid Dynamic Characteristics in Electronic Assembly

Glue jetting is the key technology in electronic assembly process.The problem is that how the equipment ejects small dot size during microelectronic encapsulation application.A 2D geometrical model is created to present needle and nozzle impact structure based on working theory of pneumatic actuator.CFD computational fluid dynamic characteristic analysis software is used to simulate glue exit velocity from nozzle orifice and to calculate hydraulic pressure inside compressed chamber.The final simulation results demonstrate that needle tip geometry dimensions and needle stroke and nozzle flared angle are the major factors to affect the jetting speed and ultimately determine the bead size.