# US 5,708,325 A · Display spacer structure for a field emission device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,325 A - Document ID: US5708325A - Status: Granted - Kind: A - Application number: 08/650,507 - Filed: 1996-05-20 - Granted: 1998-01-13 - Earliest claimed: 1996-05-20 - Assignees: Motorola, Inc. - Inventors: Clifford L. Anderson; Craig Amrine; Jeffery A. Whalin - Web page: https://patentgrep.com/patent/US5708325A ## CPC - H01J 9/242: {Spacers between faceplate and backplate} - H01J 29/864: {Spacers between faceplate and backplate of flat panel cathode ray tubes} - H01J 31/123: {Flat display tubes} - H01J 2329/8625: Spacing members - H01J 2329/863: characterised by the form or structure - H01J 2329/8665: Spacer holding means - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A method is provided for fabricating a display spacer assembly (100, 400, 500) useful in the fabrication of large-area field emission displays (200, 600). The method includes the steps of: forming slots (12, 22, 32, 33) in a substrate (10, 23, 30) thereby providing a jig; providing spacers (14, 24, 34) having lower rounded edges and upper edges; placing the lower rounded edges into the slots (12, 22, 32, 33) so that the spacers (14, 24, 34) are positioned in a predetermined layout pattern over the slotted jig surface; and placing the upper edges of the spacers (14, 24, 34) in abutting engagement with a display plate (18, 10) of a field emission display. ## Claims ### Claim 1 A field emission display comprising: a first display plate having an inner surface having a peripheral region defining an active region, the active region having a plurality of slots being formed therein; a second display plate having an inner surface having a peripheral region defining an active region, the inner surface of the first display plate opposing and being spaced apart from the inner surface of the second display plate; a plurality of spacers having first and second opposed edges, the first opposed edges being rounded and being received within the plurality of slots, the second opposed edges being in abutting engagement with the active region of the second display plate, the plurality of spacers being substantially perpendicular to the first and second display plates, each of the plurality of spacers having a height within a range of 0.5-3 millimeters and a width within a range of 50-300 micrometers, each of the plurality of spacers having a length being less than the length of the active regions of the first and second display plates whereby the shorter spacer length provides uniform vacuum conditions within the field emission display; a frame having first and second opposed surfaces, the first opposed surface being in abutting engagement with the peripheral region of the inner surface of the first display plate, the second opposed surface being in abutting engagement with the peripheral region of the inner surface of the second display plate; the active region of the first display plate, the active region of the second display plate, and the frame defining an interspace region, the plurality of spacers being disposed within the interspace region, the interspace region being evacuated; and a plurality of field emission devices being disposed within the interspace region and defining a plurality of pixels and a plurality of inter-pixel regions therebetween whereby the standoff provided by the plurality of spacers and the frame prevents implosion of the first and second display plates when vacuum conditions are provided within the interspace region. ### Claim 2 (depends on 1) A field emission display as claimed in claim 1 wherein the first display plate includes an anode and the second display plate includes a cathode, the plurality of field emission devices being disposed on the active region of the cathode. ### Claim 3 (depends on 2) A field emission display as claimed in claim 2 wherein the plurality of slots are regularly spaced apart and extend across the active region of the anode. ### Claim 4 (depends on 3) A field emission display as claimed in claim 3 wherein the active region of the anode includes a plurality of pixels defining a plurality of inter-pixel regions and wherein the plurality of slots are disposed one each within the plurality of inter-pixel regions of the anode. ### Claim 5 (depends on 2) A field emission display as claimed in claim 2 wherein the active region of the cathode includes a plurality of pixels defining a plurality of inter-pixel regions and wherein the second opposed edges of the plurality of spacers are in abutting engagement with portions of the plurality of inter-pixel regions of the cathode. ### Claim 6 (depends on 2) A field emission display as claimed in claim 2 wherein each of the plurality of slots has a depth equal to within 1.5 to 4 times the width of each of the plurality of spacers. ### Claim 7 (depends on 1) A field emission display as claimed in claim 1 wherein the thermal coefficients of expansion of the plurality of spacers and of the first and second display plates are equal. ### Claim 8 (depends on 1) A field emission display as claimed in claim 1 wherein the plurality of spacers are made from a high dielectric material being chosen from a group consisting of glass, ceramic, and quartz. ### Claim 9 (depends on 1) A field emission display as claimed in claim 1 wherein the first display plate includes a cathode and the second display plate includes an anode, the plurality of field emission devices being disposed in the active region of the cathode. ### Claim 10 (depends on 9) A field emission display as claimed in claim 9 wherein each of the plurality of slots has a depth equal to at least 3 times the width of each of the plurality of spacers, the depth being less than the height of each of the plurality of spacers. ### Claim 11 (depends on 9) A field emission display as claimed in claim 9 wherein the active region of the cathode includes a plurality of pixels defining a plurality of inter-pixel regions and wherein the plurality of slots are disposed within portions of the plurality of inter-pixel regions of the cathode. ### Claim 12 (depends on 9) A field emission display as claimed in claim 9 wherein the active region of the anode includes a plurality of pixels defining a plurality of inter-pixel regions and wherein the second opposed edges of the plurality of spacers are in abutting engagement with portions of the plurality of inter-pixel regions of the anode. ### Claim 13 (depends on 1) A field emission display as claimed in claim 1 wherein the active region of the second display plate has a plurality of slots being disposed in registration with the plurality of slots in the active region of the first display plate, the second opposed edges of the plurality of spacers being rounded and being received within portions of the plurality of slots in the active region of the second display plate. ### Claim 14 (depends on 1) A field emission display as claimed in claim 1 wherein the spacing between the inner surfaces of the first and second display plates is within a range of 0.5-1.5 millimeters. ### Claim 15 (depends on 1) A field emission display as claimed in claim 1 wherein the width of each of the plurality of spacers is within a range of 50-150 micrometers. ### Claim 16 (depends on 1) A field emission display as claimed in claim 1 wherein each of the plurality of slots has a width being between 1-5% wider than the width of each of the plurality of spacers. ### Claim 17 (depends on 1) A field emission display as claimed in claim 1 wherein the plurality of slots are regularly spaced apart and the pitch of the plurality of slots is between 250-350 micrometers.