Abstract: An automated electronic module inspection system having illumination sources that produce digitized gray scale images that are then analyzed by a computer. The inspection system illuminates the module including solder joints, components and printed circuit board using a sequence of illumination that produce visual images which are used to identify defects. The inspection system inspects for all defects as specified in MIL-STD-2000A (Section 4.4) by using both surface reflectance properties as well as topological properties of objects. The system comprises two video cameras. A positioning table aligns a module-under-test with the optical axis of each camera thereby enabling the same field-of-view to be observed under different lighting conditions. A dark field illumination associated with a first camera preferentially illuminates non-flat surfaces, but not vertical surfaces. A bright field illumination associated with a second camera preferentially illuminates relatively flat surfaces.

Abstract: A method of operating a radiation sensor is described. The sensor has a plurality of radiation sensitive devices such as photodiodes, transfer buffers associated with the radiation sensitive devices, and at least one isolation buffer identical with the transfer buffers but not associated with a radiation sensitive device. The method comprises (a) exposing the radiation sensor to radiation, whereby each radiation sensitive device stores a charge related to the total radiation incident thereon, and simultaneously sequentially reading out the contents of the transfer and isolation buffers at a regular rate; (b) transferring the charge stored in the radiation sensitive devices into the corresponding transfer buffers; and, (c) while exposing the sensor under substantially the same conditions as in step (a), sequentially reading out the contents of the transfer and isolation buffers at the same regular rate.