Patent ID: 7090554

Claim:
A method comprising: providing a spacer comprising a spacer wall having a face that has roughness which, as approximated by identical parallel cylindrical pores of pore diameter d P , corresponds to a wall porosity of at least 10% along the wall's face and a pore height h P of at least 15% of pore height parameter h MD that equals √{square root over (2 d P 2DMD /eE AV )}, where e is the electron charge, 2DMD is the median departure energy of secondary electrons emitted by the wall, and E AV is electric field strength, the roughness in the wall's face comprising depressions or/and protuberances in the wall's face, each depression or protuberance extending only partway across the wall's face; and positioning the spacer between first and second plate structures of a flat-panel display in which, during operation of the display, the second plate structure produces an image upon receiving electrons emitted by the first plate structure as an electric field of average strength E AV is directed from the second plate structure to the first plate structure.