Research on solder joint intelligent optical inspection analysis

The existing automatic optical inspection (AOI) equipment can be used to check out the defect of the electronic products, such as solder bridging, tomb stone and so on. Based on the existing AOI, a new intelligent optical inspection analysis (IOIA) technology is brought forward in this paper. The method, which combines off-line analysis and on-line contrast, is employed in the IOIA technology. That is to say, we should combine the conclusions of solder joint shape forecast and reliability analysis with on-line inspection technology of AOI smoothly. The basic principle of this method could be described as following: firstly, the structured light of monocular vision system must be improved to acquire the 3D information of practical solder joint shape. Then the relationships between solder joint shape and its reliability are introduced in this paper, and the 3D shape parameters which have significant effects to the solder joint reliability are extracted based on this relationship. Finally, contrasted the parameters of 3D shape with the data-base which established in off-line, and then the quality evaluation of solder joint could be given immediacy by using the data-base. According to the conclusions we can get the further quality evaluation and classification of the electronic products.