在MEMS麦克风贴片工艺中, 真空吸嘴吸取MEMS芯片以后需要进行芯片位姿的精确校正。为实现高速高精度贴片功能, 提出了一种基于旋转式反射镜的飞行视觉系统, 该方案利用齿轮齿条将吸嘴的升降运动转化为反射镜的旋转运动, 通过设计齿轮参数, 实现反射镜不干涉吸嘴的拾放功能。当反射镜旋转到与水平位置夹角呈45°时, 视觉系统可以获得MEMS芯片的静止的清晰图像, CCD相机采集一幅图像后, 在贴片头飞行的过程中, 控制系统完成MEMS芯片的位置和角度的校正。实验结果表明, 该系统可以获取高质量MEMS芯片图像。该系统结构简单紧凑, 成像无失真, 不限制贴片头的运动轨迹, 显著提高了MEMS芯片的贴片质量和贴片效率, 可广泛地应用于贴片机系统中。

In the die bonding process of MEMS microphone chip, the exact center and rotate angle of MEMS microphone chip is corrected after the vacuum nozzle has adsorbed it. In order to achieve high speed and precision placement function, the flying vision system based on rotating mirror is proposed. The mirror is driven to rotate by the power drawn from the nozzle rise and fall movement through a rack and pinion rack and pinion mechanism. The nozzle pick and place functions is not interfered by mirror through designing the rack and pinion mechanism parameters. The vision system can capture an static clear MEMS chip image when the mirror rotated to a 45 degrees position referenced with horizontal position. The center location and angle will be corrected by the control system during the mounted head is flying to placement position. The experimental results show that the system can obtain high-quality MEMS microphone chip image. In the proposed flying vision system, mechanical structure is simple and compact, image captured is no distortion, and there is no restriction on the mounted head movement trajectory. The flying vision system significantly enhances the quality and efficiency of SMD chip. It can be widely used in the surface mounted system.