Extracting PCB components based on color distribution of highlight areas

This paper investigates methodologies for locating and identifying the components on a printed circuit board (PCB) used for surface mount device inspection. The proposed scheme consists of two stages: solder joint extraction and protective coating extraction. Solder joints are extracted by first detecting all the highlight areas, and then recognizing and removing the invalid highlight areas which are mainly markings and via-holes. We sum up three color distribution features. And the invalid highlight areas are recognized and removed by comparing the features of the target objects and the reference objects. The sequence of color distribution as a new clue has been applied to clustering solder joints. Each protective coating is extracted by the positions of the clustered solder joints. Experimental results show that the proposed method can extract most of components effectively.