<title>Application algorithm of mathematical morphology for SMT</title>

Abstract

In this paper, we propose a new visual positioning and inspecting algorithm. The positioning algorithm is the process of computing the center position and the rotated angle of the surface mount device. The inspecting algorithm is capable of detecting the location of broken or bent leads. The morphological opening is applied to obtain a leadless image of the quad flat package or the small outline package, and the leadless image is able to be treated like an image of the square-shaped passive devices. The center position and the rotated orientation are found by four corner points which are obtained from the morphological skeleton subsets of the leadless image. After finding them, the hit and miss transform is utilized to extract the feature of the corner identification (ID). The ultimate orientation is determined correctly using results detected by hit structuring element and miss structuring element which satisfy the feature of the corner ID. The morphological inspection is executed extending over two steps, i.e., a rough inspection and a detailed inspection. The former is practiced before finding the center and the orientation, and the latter is performed after finding them.