Large area deposition of field emission cathodes for flat panel displays

摘要

The convention for field emission cathode (FEC) synthesis involves coating with a211u001every-high tolerance in thickness uniformity using a planetary substrate fixture 211u001eand a large source-to-substrate separation. New criteria for a deposition process 211u001emust facilitate a reduction in the operating voltage by increasing the density of 211u001eemitters through a reduction of cathode size and spacing. The objective of 211u001escaling the substrate size from small (less than 30 cm(sup 2)) to large (greater 211u001ethan 500 cm(sup 2)) areas further compounds manufacturing requirements to a point 211u001ebeyond that easily obtained by modifications to the convention for FEC 211u001edeposition. A new patented approach to design, assemble, and operate a coating 211u001esystem enables FEC deposition over large areas through process control of source 211u001edivergence coupled to incremental substrate positioning.