CONTOUR ACKNOWLEDGING METHOD AND SHAPE INSPECTION METHOD USING IT

PURPOSE:To calculate the mean contour position on the section in the slit beam projecting direction for each picture element width from the center-of-gravity data of a slit beam reflex image calculated one by one and to judge if the shape of the object to be acknowledged is correct upon acknowledging the continuity of them as a contour. CONSTITUTION:A lead 21, copper foil pattern 11, and solder fillet 12 are irradiated from above with a laser slit bea 31 so that the beam profile in the projecting direction becomes the section of solder in the direction over the height, and a printed circuit board 1 is moved bit by bit for a distance (y) in the Y direction, and the reflected light images with the light 31 at points f, g are photographed 4 one by one. In the center of gravity Pe of image 33 which is sliced one picture element width by width, calculation is made for the distance te between the reference line Le passing the lowest position of center of gravity and the mean value Ue of the coordinates of the center of gravity H on the left of the X-coordinate C of the center of the view field. In the same manner, tf, tg are determined for the images of points f, g, and from the meaz of them, i.e., the center-of-gravity data, the contour position of the section in the slit beam radiating direction is determined split width by width. Only the piece of products where the contour position lies within the allowable values, is judged as an acceptable piece in terms of the shape.