基于结构光的微小特征三维测量系统

A Micro Feature 3D Measurement System Based on Structured Light

针对微电子制造领域中各种微小型元件的三维测量,研究开发了一套基于结构光技术的高精度三维形貌测量系统,将工业相机与置备高精度小幅面镜头的可编程DLP投影仪结合搭建小视场三维测量系统。针对表面有突点、不连续的微小特征,研究其三维形貌测量方法,提出将四步+多波长相移算法与小视场条纹投影结合的方法来实现高精度的三维测量。针对小视场的结构光测量系统,研究高精度的投影仪标定方法,提出一种改进的标定板图案及标定算法,实现投影仪标定精度达0.189像素。将投影仪看作一个逆向相机并根据相位信息和标定参数进行三维重建。实验对标准量块及倒装芯片的晶圆突点进行测量,测得沟槽深度平均偏差为0.003 mm,晶圆突点三维重建效果良好。

For the threee-dimensional measurement of various micro components in the field of microelectronic manufacturing,this paper developed a high-precision 3D profile measurement system based on the structured light technology,which established a small field of view 3D measurement system consists of a industrial camera and a programmable DLP projector with high precision small format lens.Considering the micro features on the surface such as bumps and discontinuities,this paper studied the three-dimensional measurement of it,and proposed a method combining four steps and multiple wavelength phase shifting algorithm with small field fringe projection to achieve a high-precision 3D measurement.Specifically,for the structured light measurement system with small field of view,this paper also Studied a proposed a high-precision projector calibration method,and proposed an improved calibration plate pattern and calibration algorithm which can realize a calibration accuracy of 0.189 pixel.The projector is regarded as a reverse camera,and the points is reconstructed according to the phase information and the calibration parameters.The standard block and flip chip bump wafer are measured with experiments,the measured depth of the average error is 0.003 mm,which reflected that the effect of three-dimensional reconstruction of wafer bump is good.