Large-area FED apparatus and method for making same

A large-area field emission device (“FED”) which is sealed under a predetermined level of vacuum pressure, comprising:

• a large-area substrate;
• an emitter electrode structure disposed on the substrate such that the emitter structure is disposed over a substantial portion of the substrate;
• a plurality of groups of micropoints, with each group of micropoints having a predetermined number of micropoints and with each group of micropoints being disposed at discrete positions on the emitter electrode structure:
• an insulating layer disposed over the substrate, with the insulating layer having openings therethrough that have a diameter within a predetermined range, and with each openings surrounding at least a portion a micropoint;
• an extraction structure disposed on the insulating layer, with the extraction structure having openings therethrough that have a diameter within a predetermined range, with each openings surrounding at least a portion of a micropoints;
• and with the openings in the extraction structure being aligned with openings in the insulating layer;
• a faceplate disposed above and spaced away from the extraction structure that is transparent to predetermined wavelengths of light;
• a first conductive layer disposed on a surface of the faceplate towards the extraction structure;
• a matrix member disposed on the first conductive layer, with the matrix member defining areas of the first conductive layer surface that are to serve as pixel areas, with the pixel areas being aligned with the micropoints of a group micropoints;
• cathodoluminescent material disposed on the first conductive layer in a plurality pixel areas, with the cathodoluminescent material at a particular pixel area being aligned to receive electrons emitted from the micropoints associated that pixel area;
• and
• a plurality of spacers disposed between the faceplate and the extraction structure at predetermined locations, with the spacers having cross-sectional shapes commensurate with stresses such spacers will encounter caused by the vacuum pressure within the FED.

A large-area field emission device (“FED”) which is sealed under a predetermined level of vacuum pressure, comprising:

• a lower section of the FED that is used for generation of electron streams, further comprising,
• a base member,
• a first electrically conductive member disposed on a first surface of the base member,
• a plurality of electron emitting sources disposed at predetermined location, on first electrically conductive member, with the plurality of electron emitting sources being disposed in group of a predetermined number at the predetermined locations,
• a dielectric member disposed over the first surface of the base member covering at least the first electrically conductive member, with the dielectric member having openings therethrough surrounding at least a portion of each of the plurality of electron emitting sources, and
• a second electrically conductive member disposed on the dielectric member for causing electron streams to be emitted from the electron emitting sources, with the second electrically conductive member having openings therethrough aligned with the openings in the dielectric member and with the openings in the second electrically conductive member surrounding at least a portion of each of the plurality of electron emitting sources;
• an upper section of the FED that is spaced away from the lower section of the FED, the upper section being used for generating images based on the electron streams received from the lower section of the FED, further comprising,
• a transparent cover member,
• a third electrically conductive member disposed on a first surface of the transparent cover member,
• a matrix member disposed on the third electrically conductive member for dividing a surface the third conductive member on which the matrix member is disposed into a plurality of cells, and
• cathodoluminescent material disposed on the third electrically conductive member in a plurality of the cells, with the cathodoluminescent material at a particular cell being aligned to receive the electron stream emitted from the electron emitting sources associated that cell;
• and
• a plurality of standoff members disposed between the upper and lower sections of the FED, with the standoff members having different heights at different location based on stresses exerted on the standoff members.

A large-area field emission device (“FED”) which is sealed under a predetermined level of vacuum pressure, comprising:

• a lower section of the FED that is used for the generation of electron streams, further comprising,
• a base member,
• a first electrically conductive member disposed on a first surface of the base member,
• a plurality of electron emitting sources disposed at predetermined location on first electrically conductive member, with the plurality of electron emitting sources being disposed in group of a predetermined number at the predetermined locations,
• a dielectric member disposed over the first surface of the base member covering at least the first electrically conductive member, with the dielectric member having openings therethrough surrounding at least a portion of each of the plurality of electron emitting sources, and
• a second electrically conductive member disposed on the dielectric member for causing electron streams to be emitted from the electron emitting sources, with the second electrically conductive member having openings therethrough aligned with the openings in the dielectric member and with the openings in the second electrically conductive member surrounding at least a portion of each of the plurality of electron emitting sources;
• an upper section of the FED that is spaced away from the lower section of the FED, the upper section being used for generating images based on the electron streams received from the lower section of the FED further comprising,
• a transparent cover member,
• a third electrically conductive member disposed on a first surface of the transparent cover member,
• a matrix member disposed on the third electrically conductive member for dividing a surface the third conductive member on which the matrix member is disposed into a plurality of cells, and
• cathodoluminescent material disposed on the third electrically conductive member in a plurality of the cells, with the cathodoluminescent material at a particular cell being aligned to receive the electron stream emitted from the electron emitting sources associated that cell;
• and
• a plurality of standoff members disposed between the upper and lower sections of the FED, with the standoff members having different cross-sectional shapes at different location based on stresses exerted on the standoff members.

A method for forming and associating a lower section of a large-area field emission device (“FED”) which is sealed under a predetermined level of vacuum pressure with an upper section of a large-area FED, with an upper section of the FED including a faceplate, a first conductive layer disposed on a surface of the faceplate, a matrix member disposed on a surface of the first conductive layer, and cathodoluminescent material disposed on the first conductive layer in areas not covered by the matrix member, comprising the steps of:

• (a) forming a substrate of a predetermined size;
• (b) forming an emitter electrode structure on the substrate;
• (c) forming a plurality micropoints in a predetermined height range on the emitter electrode structure, with the micropoints being formed in groups on the emitter electrode structure;
• (d) coating the micropoints with a low work function material;
• (e) depositing an insulating layer over the substrate, emitter electrode structure, and plurality of micropoints;
• (f) depositing a first conductive layer over the insulating layer, with a combined height of the insulating and first conductive layers being at least as high as the tallest coated micropoint;
• (g) controlled polishing of a first surface of the first conductive layer to achieve a substantially smooth, flat first surface, with a combined thickness of the insulating and first conductive layer being substantially uniform across the FED;
• (h) etching openings through the conductive and insulating layers to expose the coated micropoints, with walls of the openings being spaced away from the micropoints;
• (i) disposing a plurality spacers between the upper and lower sections of the FED to provide a predetermined separation between the upper and lower sections, with the spacers having heights commensurate with stresses exerted on the spacers.

A method for forming and associating a lower section of a large-area field emission device (“FED”) which is sealed under a predetermined level of vacuum pressure with an upper section of a large-area FED, with an upper section of the FED including a faceplate, a first conductive layer disposed on a surface of the faceplate, a matrix member disposed on a surface of the first conductive and cathodoluminescent material disposed on the first conductive in areas not covered by the matrix member, comprising the steps of:

• (a) forming a substrate of a predetermined size;
• (b) forming an emitter electrode structure on the substrate;
• (c) forming a plurality micropoints in a predetermined height range on the emitter electrode structure, with the micropoints being formed in groups on the emitter electrode structure;
• (d) coating the micropoints with a low work function material;
• (e) depositing an insulating layer over the substrate, emitter electrode structure, and plurality of micropoints;
• (f) depositing a first conductive layer over the insulating layer, with a combined height of the insulating and first conductive layers being at least as high as the tallest coated micropoint;
• (g) controlled polishing of a first surface of the first conductive layer to achieve a substantially smooth, flat first surface, with a combined thickness of the insulating and first conductive layer being substantially uniform across the FED;
• (h) etching openings through the conductive and insulating layers to expose the coated micropoints, with walls of the openings being spaced away from the micropoints;
• (i) disposing a plurality spacers between the upper and lower sections of the FED to provide a predetermined separation between the upper and lower sections, with the spacers having cross-sectional shapes commensurate with stresses exerted on the spacers.