| 摘要 |
PURPOSE: To detect a three-dimensional shape without being influenced by the warp of a substrate, by controlling the height of a stage based on the estimated height or the like of the surface of the substrate with feed-forward-method. CONSTITUTION: An XYZ stage 2 holding a substrate 1 on which a part is to be mounted is controlled by an XY stage control part 3 and a Z stage control part 4. A three-dimensional shape signal-generating part 7, when receiving surface height data of tone substrate 1 from a height-detecting optical system 6, generates a three-dimensional shape signal of the substrate 1. An image- processing part 8 processes the three-dimensional shape signal to detect a fault. A substrate height-detecting part 9 detects the height of the surface of the substrate 1 for every window. A substrate height-estimating part 10 predicts the surface height or inclination at the next window, based on which height control data are generated and sent to the control part 4. In other words, since the height of the stage 2 is controlled in a feed-forward-method, focus is always met on the surface of the substrate 1 whether a part is mounted or not. |
