Robert C Holm

US Patent:

39992632, Dec 28, 1976

Filed:

Nov 14, 1974

Appl. No.:

5/523668

Inventors:

Frederick John Marshall - Redwood City CA
Robert Leander Holm - Sunnyvale CA

Assignee:

Litton Systems, Inc. - San Carlos CA

International Classification:

H01J 902

US Classification:

29 2514

Abstract:

The disclosed method of forming a control grid assembly having separate co-planar spaced grids for the electron gun of a multibeam cathode ray tube, includes the steps of forming a pair of identical metal wafers having two spaced holes, forming two waferlike insulating members having elongated slots, and forming a flat metal member having a rectangular framelike portion and a plurality of elongated spaced metal fingers extending to opposed frame portions inwardly toward one another within the frame portion and with opposed fingers separated by a distance less than the width of said slots. A sandwich of elements is formed with the third metal member in the center, an insulator member on each side thereof, and a metal member overlying said insulator members, and this assembly is aligned so that the holes of said members and said slots are in line, including aligning with a pin extended through opposed overlying holes and said intermdiately located slots, and with the end portion of each of said projecting metal fingers extending into the windows formed by each of the slots. The assembly is diffusion bonded to form a unitary assembly and a coolant fluid is introduced into the slots via said holes for cooling the sandwich and electrical discharge machining a plurality of minute holes through the sandwich at locations in line with corresponding ones of said projecting fingers so as to form a plurality of minute passages through each of the members and the projecting finger, and wherein eroded material may be flushed out from the slots by said fluid through said relatively large holes, and cutting away a portion of the framelike portion of the metal member to leave portions of spaced metal fingers extending outwardly from the sandwich of elements.