Feature-Based Object Location of IC Pins by Using Fast Run Length Encoding BLOB Analysis

To speed up the object location for the IC packaging inspection, this paper develops a novel binary large object (BLOB) analysis algorithm by using run length encoding (RLE). First, the new data structures for RLE and BLOB-linked lists are designed to accelerate the access and modifications of data. Second, to avoid the traditional labeling conflicts and simplify the comparisons of connectivity branches, an efficient algorithm for BLOB analysis is presented. Furthermore, area feature of objects can be extracted when the BLOB-linked list are dynamically created or modified. Finally, to evaluate the performance of the proposed method, ICs with various types of small outline packaging packages were located by the proposed algorithm. The experimental results not only demonstrate that the IC pins could be effectively and robustly located with the proposed algorithm, but also show that the presented algorithm runs faster than other classical methods.