SUBSTRATE INSPECTION METHOD

PURPOSE:To securely inspect a misalignment by obtaining the complete silhouette image of a component by applying preflux which contains an ultrasonic-ray excited fluorescent agent and picking up an image of the substrate where the component is mounted while the substrate is radiated with an ultrasonic ray. CONSTITUTION:Parameters (decision data) of respective components 13-1a-13-na on a reference printed board 10-1 which are obtained by picking up the image of the reference printed board 10-1 are compared with parameters (data to be inspected) of respective components 13-1b-13-nb on a printed board 10-2 to be inspected which are obtained by picking up the image of the printed board 10-2 to be inspected to detect the misalignments of those respective components (13-1b)-(13-nb) when they shift in position. In such a case, the board 11 is coated with the preflux 45 which contains the ultraviolet-ray excited fluorescent agent before the components 13-1a-13-na are mounted on the raw board 11 to obtain the color of the raw board 11 and the accurate silhouette image of the respective components 13-1a-13-na.