Incandescent "microfilaments" for integrated display devices, and the like, are batch fabricated using planar technologies. The planar incandescent filaments are made of thin films, suspended to minimize heat conduction losses. Heat losses are additionally minimized by appropriately shaping the ends of the filaments. By utilizing planar technologies all filaments of a display device may be fabricated en masse in a single plane and, individual filaments may be etched to various shapes and curves thereby obviating the problems encountered where elements must be strung between support posts, in a straight line. Typically, a ceramic substrate is first coated with a layer of reflecting material and etched, if desired, to the pattern selected for the reflecting surface. Thereafter, a support material, such as glass, is deposited over the substrate and reflecting material. Holes are then drilled into the glass and substrate and filled with conductive material, to thereby form support posts. A filament material, such as tungsten, is then deposited over the support layer so as to make conductive contact with the underlying support posts. By using conventional etching techniques a filament of desired pattern is then formed between the posts. Thereafter the support layer may be etched away leaving the filament suspended between the posts.
24 Claims, 23 Drawing Figures
 TECHNIQUE FOR FABRICATING INTEGRATED INCANDESCENT DISPLAYS
 Inventors: Alan V. Brown; Frederick Hochberg, both of Yorktown Heights, N.Y.
 Assignee: International Business Machines Corporation, Armonk, N.Y.
 Filed: April 29,1971
 Appl.No.: 138,409
 U.S.C1 29/25.11,313/109.5
 Int.Cl H01J9/00
 Field of Search 313/109.5; 29/25.13, 25.14,
29/25.15,25.16,25.18,424,625,604, 25.11; 316/17,23
 References Cited
UNITED STATES PATENTS
3,583,066 6/1971 Carbonel 29/604
3,408,523 10/1968 Demarest et al 313/109.5
Primary Examiner—Charles W. Lanham
Assistant Examiner—James W. Davie
Attorney—Hanifin and Jancin and John A. Jordan