INTEGRATED CONTROL GRIDS FOR CRTs
Original Publication Date: 1989-May-01
Included in the Prior Art Database: 2005-Jan-27
An integrated grid structure to produce and cut off multiple electron beams from a single cathode can be made using a variety of metals and insulators by photoresist techniques. A particular system using sapphire and tungsten is illustrated. Alignment of the front electrodes to the back hole and overhang of the front electrode, desirable to reduce insulator charging, both derive automatically from this technique. Both sides of a sapphire wafer 10 are coated with a metal 12, 14 suitable for use as an electrode in a vacuum device (i.e., no electron emission, and stable at high temperatures). Clear areas 16 are left on the top surface as shown in Fig. 1. The metal 14 on the back side is etched into the desired pattern for the holes to be etched into the sapphire 10.