Abstract: A green sheet holding apparatus includes a first member secured to a first edge of the green sheet and a second member moveable relative to the first member, the second member being secured to a second edge of the green sheet. A forcing mechanism, connected to the second member and to the first member, forces the second member away from the first member such that the first edge and the second edge of the green sheet are forced away from each other and the green sheet is flattened. The holding apparatus may be included in a green sheet inspection system, wherein the inspection system further includes a light source directing a light onto the green sheet and a camera detecting light from the green sheet. The invention also includes a method of holding a green sheet, which includes securing the first edge of the green sheet to a first member, securing the second edge of the green sheet to a second member, and forcing the second member away from the first member.

Abstract: A calibration system for circuit inspection tools in which analog threshold levels are automatically set by digital signals. The inspection too includes an optical detector system that provides video signals to channels each containing an analog processor. In the analog processor an analog reference signal, an analog video inspection signal which may contain a defect indication and a digital threshold signal are employed. The digital threshold signal is converted into an analog threshold signal which is summed with the analog reference signal that has been inverted. The inverted, thresholded reference signal is then summed with the analog video signal. The summed analog video signal and thresholded reference signal is compared with a zero level. If the sum is greater than zero a defect is indicated.

Abstract: A method and apparatus for the inspection and handling of surface level defects is taught. Briefly stated, the object to be inspected is positioned. A Laser light is polarized into at least one orientation and then reflected off of a rotated polygon mirror. This causes the light to "move" over the area of interest. A plurality of fiber optic bundles are used to receive and conduct the reflected light back to photomultipliers. The photomultipliers convert the light into electrical signals while associated electronics digitize the signals, keeping track of pixels which are produced. By keeping track of pixel edge boundaries and determining if certain thresholds are exceeded or not met as appropriate, the area of interest can be checked for a variety of defects. By comparison of the defects to a reference base, the defects and hence the items inspected can be categorized.

Abstract: A method and apparatus for the inspection and handling of surface level defects is taught. Briefly stated, the object to be inspected is positioned. A Laser light is polarized into at least one orientation and then reflected off of a rotated polygon mirror. This causes the light to "move" over the area of interest. A plurality of fiber optic bundles are used to receive and conduct the reflected light back to photomultipliers. The photomultiplers convert the light into electrical signals while associated electronics digitize the signals, keeping track of pixels which are produced. By keeping track of pixel edge boundaries and determining if certain thresholds are exceeded or not met as appropriate, the area of interest can be checked for a variety of defects. By comparison of the defects to a reference base, the defects and hence the items inspected can be categorized.