Patent RU-2713381-C1 (RU)
Title: Method for fabrication of cathode-grid assembly with field-emission cathode
Inventor: GOREVA TATYANA ALEKSANDROVNA
IPC: H01J1/304
Filed: 2019-07-01
Granted: 2020-02-05
Abstract: FIELD: electronic equipment. 
     SUBSTANCE: invention relates to the field of electronic equipment, namely to the field of cathode-grid assemblies (CGA) with field-emission cathodes for vacuum electronic devices, mainly devices with microsecond readiness time. Method for manufacturing of CGA with field-emission cathode includes formation on field of field-emission cathode of solid array of auto-emission structures; manufacturing of pulling grid; manufacturing of a metal-ceramic assembly comprising a field-emission cathode holder, an electrical insulator and a pull-out grid holder, arrangement and fixing of the auto-emission cathode in the field-emission cathode holder; arrangement and attachment of drawing grid in holder of pull grid above working surface of field-emission cathode with vacuum gap between field-emission cathode and pull-out grid. Besides, process electric insulator and solid process anode are placed and fixed above drawing grid, with possibility of their detachment and removal; CGA is arranged with process electric insulator and solid process anode in vacuum chamber; connecting field-emission cathode, pulling grid and process anode with electrical terminals of electric power source; evacuating vacuum chamber with CGA assembly with process electric insulator and solid process anode to pressure not higher than 10 -5  mm Hg (1.33⋅10 -3  Pa); supplying to the drawing grid a constant or pulse positive relative to field-emission cathode, electric voltage with its increase until field-emission current occurrence in electric circuit "field-emission cathode-pull-out grid"; applying to the process anode a negative voltage relative to the field emission cathode of minimum value, at which field emission current in the electric circuit "field emission cathode – pulling grid" receives minimum value; electric voltage on process anode and pull-out grid is increased in absolute value, in proportion and without changing polarity, to values, at which field-emission current growth in electric circuit "field-emission cathode-pull-out grid" is terminated and part of array of field-emission structures on surface of field-emission cathode is destructed in places located opposite to jumpers of drawing grid, and integrity and serviceability of field-emission structures on surface of field-emission cathode in places located opposite holes in pull-out grid, is preserved due to locking field emission from them with electric field of process anode; lowering to zero electric voltage on drawing grid; reducing to zero electric voltage on process anode; increasing pressure in vacuum chamber with CGA assembly with process electric insulator and solid process anode to atmospheric one; disconnecting field-emission cathode, drawing grid and process anode from electrical terminals of electric power supply source; is removed from CGA vacuum chamber with process electrical insulator and solid process anode; disconnecting and removing process anode and process electric insulator from CGA manufactured with such method with field-emission cathode. 
     EFFECT: high accuracy of positioning field-emission structures opposite openings in a drawing grid, low field emission current of the drawing grid in operating conditions of the CGA and thereby improving reliability and durability thereof. 
     1 cl, 3 dwg