基于点云处理的QFP芯片引脚三维测量

Three-dimensional Measurement of QFP Chip Pins Based on Point Cloud Processing

为了避免利用2D图像提取特征点并进行三维重建的烦琐,同时满足芯片引脚3D测量指标的高精度要求,采用点云处理技术,提出一种基于法向量差异的点云水平校准方法,将该方法与最小外包围盒算法相结合来剔除芯片内部引脚点云。对剩余点云进行聚类分割后,利用采样一致性算法对芯片各外部引脚、上下表面进行平面方程参数拟合并求解各引脚区域的中点。通过以上获取的数据计算芯片高度、引脚栈高以及引脚翘起度。最后,通过试验验证了所述芯片测量方案的有效性。

In order to aviod the complexity of extracting feature points from 2D images and performing 3D reconstruction, and to meet the requirement of high precision of 3D measurement index of chip pins, this paper proposes a horizontal calibration method of point clouds based on difference of normal vectors by using point cloud processing technology, and combines this method with the minimum outer bounding box algorithm to eliminate the point clouds of chip internal pins. After clustering and segmenting the remaining point clouds, the plane equation parameters of each external pin, upper and lower surfaces of the chip are fitted by using the sampling consistency algorithm, and the midpoint of each pin area is solved. Calculate packege height, stand off and foot angle through the data obtained above. Finally, the effectiveness of this chip measurement scheme is verified by experiments.