Abstract: A system for inspecting potentially warped printed circuit board assemblies is disclosed. The system includes an inspection head with an axial, centrally located camera, and a laser disposed at an angle off the central axis. The central camera and the angled laser can be used during an initial scan of a printed circuit board assembly to measure and compensate for warp in the assembly, thereby making a subsequent inspection of the assembly more accurate.

Abstract: An apparatus and method for inspecting a printed circuit board, whereby a list of windows encompassing respective regions of the printed circuit board are generated. The windows are then scanned, and data representing the respective regions is captured and stored. The captured data includes data relating to a plurality of pixels for each window. Next, data relating to a plurality of adjacent pixels is retrieved, and values of the adjacent pixels are summed. Finally, either the data relating to the plurality of adjacent pixels or the sum of adjacent pixel values is selected for use in subsequent processing. The apparatus and method is especially useful for determining an average brightness level for each window.

Abstract: A method is available for inspecting a printed circuit board and solder paste deposited upon the printed circuit board, whereby both systematic defects occurring during a solder paste deposition process and random defects are located. The printed circuit board is continuously scanned by an inspection head immediately following the solder paste deposition process. Images of the printed circuit board are then analyzed for random defects such as missing solder paste, improper solder paste coverage, and solder bridging. Next, heights of solder paste deposits are sampled. A pattern of light is projected upon selected solder paste deposits, and images of the selected solder paste deposits are captured. Light triangulation techniques are then used for determining the height of each selected solder paste deposit. Variations in the height of solder paste are systematic defects occurring in the solder paste deposition process.

Abstract: A printed circuit board inspection system acquires images for purposes of inspection from viewing fields defined along the surface of the printed circuit board to be inspected which can be varied in size to accommodate the density and tolerance of components associated with the printed circuit board under inspection. To this end, the cameras of the inspection head associated with the printed circuit board inspection system are provided with zoom lenses, which are capable of controlled operation responsive to the existing microprocessor systems of the printed circuit board inspection system. This allows the magnification of images acquired by the cameras to be varied, as desired, in turn varying the size of the viewing fields defined for inspection purposes. The inspection head is then operated at a rate commensurate with the size of the viewing fields which have been selected.

Abstract: A method and apparatus for inspecting articles such as printed circuit boards doubles the transport rate for the article under inspection, and modifies the manner in which acquired video images are processed to account for this change in rate. Primarily, this involves two modifications to existing video processing systems including a change in synchronization for obtaining the frames which are to be processed, and a selective exposure (i.e., shuttering) of the video cameras to the images which are to be acquired in order to avoid the acquisition of plural images in a single frame. Once acquired, the video images are stored and processed making use of techniques which substantially correspond to those previously employed by existing inspection devices of this general type.

Abstract: A printed circuit board inspection device includes a lighting system for use with the series of cameras associated with the printed circuit board inspection device which is essentially domed in configuration, and which incorporates a plurality of selectively controllable light emitting diodes for developing desired lighting patterns. The light emitting diodes are arranged within the domed fixture to form an array of defined latitudes and longitudes, and are capable of selective activation to develop the particular lighting patterns which are desired. This permits an acquisition of images useful in developing a "topographical display" of the acquired image, which is useful in enhancing the subsequent inspections which are to be performed.