Abstract: A system for testing for opens in and shorts between conductor traces on a printed circuit board includes an electron gun assembly for generating an electron beam and an electron optics assembly for directing the beam to the traces which have a reference potential. A grid located proximate to and substantially parallel with the surface of the board is placed at a first potential before the beam is directed to a first point on a trace to charge the trace to a first potential. The grid is then placed at a second potential, the second potential being between the reference potential and the first potential, before the beam is directed to a second point on the trace to cause emission of secondary electrons. The secondary electrons that reach the grid are collected thereby, and signal processing electronics are used to determine whether or not an open or short exists.

Abstract: A system for testing for opens in and shorts between conductor traces on a printed circuit board is provided. The system includes an electron gun assembly for generating an electron beam and an electron optics assembly for directing the electron beam to the traces on the surface of the board, the traces having a reference potential. A grid located proximate to and substantially parallel with the surface of the board is placed at a first potential before the electron beam is directed to a first point on a trace to charge the trace to a first potential. The grid is then placed at a second potential, the second potential being between the reference potential and the first potential, before the electron beam is directed to a second point on the trace to cause emission of secondary electrons.

Abstract: A method and apparatus are described for improving the geometric fidelity of images reproduced in a charged particle beam device. The beam is deflected across a sensitive medium to form a test image of predetermined configuration. The test image is compared with a reference image and geometric deviations measured, at a number of points, are used to calculate correction signals required to modify the beam deflection to offset the deviations. Circuit adjustments are then made to provide the calculated correction signals. The correction signal adjustments are accomplished in separate non-interactive circuits for each of a plurality of predetermined corrections which only require a one time adjustment.

Abstract: An improved particle beam recorder system is provided having a film gate which includes a referencing means for providing at least two differently shaped registration holes in a recording film substrate. The referencing means lock in, secure, and define the film position relative to a film receiving surface of a film gate during exposure imaging and thereby establish a defined relation between the image field and the film substrate and more particularly the registration holes thereof. The developed film image can thereafter be positioned in a predefined or desired relationship in a display means by aligning the registration holes of the film with suitable pegs of the display means. The registration holes also advantageously permit the images of exposed and developed films to be aligned relative to one another to permit accurate superimposition.The referencing means for producing the registration holes can be punch means which pierce the film.