PCB元件高度测量项目方案20140326.pptVIP

PCB元件高度测量项目方案 PCB Component Height Measurement Project Plan Ver4.0 2014-03-26 东莞乐琪光电科技有限公司 使用激光线扫描来获取被测对象的三维信息，从而实现高度测量功能。 The laser ray is used to scan the measured objects and obtain their 3D information to achieve the measured intention. 检测基本原理 Basic inspection principle 激光三角法 The laser trigonometry principle 如左图所示，根据激光器和相机的位置，以及图像中光斑的位置，可依据以下公式计算出被测对象的高度。 As shown in the left figure, The height of the measured object can be calculated according to the position and posture of the laser, camera and image spot. 检测过程 The inspection process 检测流程如上图所示。 The inspection process is shown above. 检测过程 The inspection process 制程制作 The inspection process 1. Mark点 Mark Points Mark点用于对PCB板的位置和姿态进行校正，一般添加在PCB板对角的位置上。Mark点定位目前提供基于灰度匹配，几何匹配两种算法。 Mark points are used to adjust the position and posture of the PCB which usually be added at the two corners of the PCB. Gray based match algorithm and geometric based matching algorithm are offered to the mark positioning. 制程制作 The inspection process 2. 基准点 Reference Points 基准点作为测量元件高度的参考点，减少因为电路板变形等造成的测量误差。取基准窗范围内的平均高度作为基准点的高度。 The reference points are use to as the benmarks of the component height to reduce the influence of the measure errors. The average height of the reference window as the reference height. 制程制作 The inspection process 3. 被测元件 Measured components 在需要测量的元件位置添加相应的元件窗口，并指定其附近的参考点作为该元件的参考点。 Component windows are added at the component position, and assign the reference points near the component as the measure basis. 判定计算原理The determining principle 元件高度计算判定 Component height assessment 对于每个被测元件： 元件高度 = 元件绝对高度 - 基准点高度 如果元件高度预设值，则判定为NG；否则，判为OK。 For every component: height = Absolute height - reference height If height pre-defined value, the result is NG; else, the result is OK. 通过模板匹配定位元件位置，通过边缘有哪些信誉好的足球投注网站定位电路板边缘，比较二者的位置关系即可判定元件是否歪斜。 The component location can be positioned with the template match, and the PCB edge can be find with the edge detection algorithm, then whether the component is skew