THREE DIMENSIONAL INSPECTION SYSTEM

摘要

A part inspection and calibration method for the inspection of printed circuit boards and integrated circuits includes a camera (10) to image a precision pattern mask (Fig. 4) deposited on a transparent reticle (20). Small parts (30) are placed on or above the transparent reticle (20) to be inspected. An overhead mirror or prism (40) reflects a side view of the part (30) under inspection to the camera (10). The scene of the part (30) is triangulated and the dimensions of the system can thus be calibrated. A precise reticle mask (Fig. 4) with dot patterns gives an additional set of information needed for calibration. By imagining more than one dot pattern the missing state values can be resolved using an iterative trigonometric solution. The system optics are designed to focus images for all perspectives without the need for an additional focusing element.