Method and apparatus for inspecting solder portions using fuzzy inference

摘要

An image of the solder portion is taken. Values of goodness/poorness judgment factors are calculated from the image of the solder portion. Grades of the goodness/poorness judgment factors are calculated from the values of the goodness/poorness judgment factors and from predetermined membership functions of the goodness/poorness judgment factors according to predetermined rules each having a condition part related to the goodness/poorness judgment factors and a conclusion part related to a goodness degree. Partial figures are calculated from predetermined membership functions of the goodness degree and from the calculated grades of the goodness/poorness judgment factors. The partial figures are combined into a final figure. A position of a centroid of the final figure is calculated. A decision is made as to whether or not the solder portion is good on the basis of the calculated position of the centroid with respect to a predetermined judgment scale.