Surface grid technique for noncontact e-beam testing of very large scale integrated package substrate

A surface grid assisted charging technique for noncontact e-beam testing of very large scale integrated package substrates has been developed. Successful charging of packages with a variety of combination of conductor/substrate materials (i.e., Au/alumina ceramic, Mo/alumina ceramic, Solder/polyimide, and chromium/polyimide) has been demonstrated using this technique. In this paper, both theoretical and experimental results concerning the role of a surface grid in addressing various testing issues such as package material parameters, charge localization, secondary electron redistribution, local field effect, and the electron detector response characteristic will be discussed.