Internal plate flat-panel field emission display

• US 5,766,053 A
• Filed: 07/31/1996
• Issued: 06/16/1998
• Est. Priority Date: 02/10/1995
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Watkins, Charles, Cathey, David A.
• Primary Examiner(s): Ramsey, Kenneth J.
• Application Number:
  US08/690,012
• Time in Patent Office: 685 Days
• Field of Search: 445/25, 445/24, 313/497, 313/495
• US Class Current: 445/25
• CPC Class Codes: H01J 2329/8625 Spacing members
• CPC Class Codes: H01J 2329/92 Means forming part of the display panel for the purpose of providing electrical connection to it
• CPC Class Codes: H01J 29/90 Leading-in arrangements; Seals therefor
• CPC Class Codes: H01J 29/94 Selection of substances for gas fillings; Means for obtaining or maintaining the desired pressure within the tube, e.g. by gettering exhausting, degassing, gettering of electric discharge tubes in general H01J9/38
• CPC Class Codes: H01J 31/127 using large area or array sources, i.e. essentially a source for each pixel group

Abstract

A flat-panel field emission display comprises a luminescent faceplate, a rigid backplate, and an interposed or sandwiched emitter or cathode plate. A positioning spacer or connector ridge is formed on the rear surface of the faceplate to space the cathode plate a fixed distance behind the faceplate. A peripheral seal is formed between the faceplate and the backplate. The faceplate, backplate, and peripheral seal define an evacuated internal space which contains the cathode plate. The backplate is spaced behind the cathode plate to create a rearward vacuum space in which a getter is located.

Claims

1. A method of fabricating a flat-panel field emission display, comprising:

forming an emitter matrix on a front surface of a cathode plate;

providing a luminescent faceplate having a rear surface;

mounting the cathode plate to the luminescent faceplate at a spaced distance from the rear surface of the luminescent faceplate;

affixing a backplate to the luminescent faceplate behind the cathode plate;

spacing the backplate from the luminescent faceplate to create an internal space between the backplate and luminescent faceplate, the internal space containing the cathode plate and creating a rearward vacuum space behind the cathode plate;

evacuating the internal space between the backplate and luminescent faceplate;

forming a connector ridge on the rear surface of the luminescent faceplate;

forming a plurality of conductive traces which overlie the rear surface of the luminescent faceplate and which extend over the connector ridge;

aligning bond pads on the cathode plate with portions of the conductive traces which extend over the connector ridge; and

pressing the cathode plate against the faceplate to form conductive bonds between the cathode plate bond pads and the conductive traces.

2. A method as recited in claim 1 and further comprising attaching the cathode plate to the faceplate with flip-chip connections between the cathode plate bond pads and the conductive traces.

3. A method as recited in claim 1 and further comprising:

providing metal bumps between the conductive traces and the cathode plate bond pads prior to the step of pressing the cathode plate against the faceplate;

the metal bumps forming the conductive bonds between the cathode plate bond pads and the conductive traces as a result of pressing the cathode plate against the faceplate; and

the conductive bonds forming adhesion connections between the faceplate and the cathode plate to mount the cathode plate to the faceplate.

4. A method as recited in claim 1 wherein the conductive traces have base portions which overlie the faceplate and corresponding connecting portions which overlie the connector ridge;

the method further comprising;

wire bonding the base portions of individual conductive traces to their corresponding connecting portions.

5. A method as recited in claim 1 wherein the conductive traces have base portions which overlie the faceplate and corresponding connecting portions which overlie the connector ridge;

the method further comprising;

wire bonding the base portions of individual conductive traces to their corresponding connecting portions; and

providing metal bumps between the conductive traces and the cathode plate bond pads prior to the step of pressing the cathode plate against the faceplate, the metal bumps forming the conductive bonds between the cathode plate bond pads and the conductive traces as a result of pressing the cathode plate against the faceplate.

6. A method as recited in claim 1 wherein the conductive traces have base portions which overlie the faceplate and corresponding connecting portions which overlie the connector ridge;

the method further comprising;

wire bonding the base portions of individual conductive traces to their corresponding connecting portions; and

bonding stubs of bond wire either to individual conductive trace connecting portions or to individual cathode plate bond pads, the bonded stubs having projecting tails of bond wire which are interposed between the cathode plate bond pads and the conductive traces to form the conductive bonds between the cathode plate bond pads and the conductive traces to conductively bond therebetween.

7. A method as recited in claim 1 and further comprising bonding stubs of bond wire either to individual conductive trace connecting portions or to individual cathode plate bond pads, the bonded stubs having projecting tails of bond wire which are interposed between the cathode plate bond pads and the conductive traces to form the conductive bonds between the cathode plate bond pads and the conductive traces.

8. A method as recited in claim 1 and further comprising:

adjusting a wire bonder'"'"'s tear length to a setting which leaves a projecting tail of severed bond wire at terminating wire bond connections;

making wire bonds to individual conductive trace connecting portions with bond wire from the wire bonder; and

severing the bond wire adjacent said individual conductive trace connecting portions, the adjusted tear length of the wire bonder resulting in tails of severed bond wire which project from said individual conductive trace connecting portions to form the conductive bonds between the cathode plate bond pads and the conductive traces.

9. A method of fabricating a flat-panel field emission display, comprising:

forming an emitter matrix on a front surface of a cathode plate;

providing a luminescent faceplate having a rear surface;

forming a connector ridge on the rear surface of the luminescent faceplate;

forming a plurality of conductive traces with base portions overlying the faceplate rear surface and connecting portions overlying the connector ridge;

electrically connecting the base and connecting portions of individual conductive traces;

aligning bond pads on the cathode plate with conductive trace connecting portions; and

pressing the cathode plate against the faceplate to form conductive bonds between the cathode plate bond pads and the conductive traces.

10. A method as recited in claim 9 and further comprising attaching the cathode plate to the faceplate with flip-chip connections between the cathode plate bond pads and the conductive traces.

11. A method as recited in claim 9 and further comprising:

providing metal bumps between the conductive trace connecting portions and the cathode plate bond pads prior to the step of pressing the cathode plate against the faceplate;

the metal bumps forming the conductive bonds between the cathode plate bond pads and the conductive traces as a result of pressing the cathode plate against the faceplate; and

the conductive bonds forming adhesion connections between the faceplate and the cathode plate to mount the cathode plate to the faceplate.

12. A method as recited in claim 9 and further comprising wire bonding the base portions of individual conductive traces to their corresponding connecting portions.

13. A method as recited in claim 9 and further comprising:

wire bonding the base portions of individual conductive traces to their corresponding connecting portions; and

providing metal bumps between the conductive trace connecting portions and the cathode plate bond pads prior to the step of pressing the cathode plate against the faceplate, the metal bumps forming the conductive bonds between the cathode plate bond pads and the conductive traces as a result of pressing the cathode plate against the faceplate.

14. A method as recited in claim 9 and further comprising:

wire bonding the base portions of individual conductive trace to their corresponding connecting portions; and

bonding stubs of bond wire either to individual conductive trace connecting portions or to individual cathode plate bond pads, the bonded stubs having projecting tails of bond wire which are interposed between the cathode plate bond pads and the conductive traces to form the conductive bonds between the cathode plate bond pads and the conductive traces.

15. A method as recited in claim 9 and further comprising:

wire bonding the base portions of individual conductive traces to their corresponding connecting portions; and

attaching the cathode plate to the faceplate with flip-chip connections between the cathode plate bond pads and the conductive traces.

16. A method as recited in claim 9 and further comprising bonding stubs of bond wire either to individual conductive trace connecting portions or to individual cathode plate bond pads, the bonded stubs having projecting tails of bond wire which are interposed between the cathode plate bond pads and the conductive traces to form the conductive bonds between the cathode plate bond pads and the conductive traces.

17. A method as recited in claim 9 and further comprising:

adjusting a wire bonder'"'"'s tear length to a setting which leaves a projecting tails of severed bond wire at terminating wire bond connections;

making wire bonds to individual conductive trace connecting portions with bond wire from the wire bonder; and

severing the bond wire adjacent said individual conductive trace connecting portions, the adjusted tear length of the wire bonder resulting in tails of severed bond wire which project from said individual conductive trace connecting portions to form the conductive bonds between the cathode plate bond pads and the conductive traces.

18. A method of fabricating a field emission display, comprising:

providing an emitter matrix on a cathode plate, the cathode plate having at least one electrically conductive first bonding area in electrical connection with the emitter matrix;

providing at least one external plate having an internal surface, at least one second bonding area being associated with the internal surface of the external plate;

providing a projecting tail of a conductor from at least one of the first and second bonding areas;

positioning the cathode plate and the external plate with their first and second bonding areas facing one another in alignment, the projecting conductor tail being interposed between the first and second bonding areas; and

pressing the cathode plate and the external plate against each other, the projecting conductor tail deforming between the first and second bonding areas to conductively bond therebetween.

19. A method as recited in claim 18 wherein the projecting conductor tail is provided from the second bonding area.

20. A method as recited in claim 18 wherein the second bonding area is formed on a connector ridge formed on the internal surface of the external plate.

21. A method as recited in claim 18 wherein the one external plate is a luminescent faceplate, the second bonding area being formed on a connector ridge formed on the internal surface of the luminescent faceplate.

22. A method as recited in claim 18 further comprising providing a discrete interconnecting wire extending from the second bond area to a location remote of the cathode plate.

23. A method as recited in claim 18 wherein the second bonding area is formed on a connector ridge formed on the internal surface of the external plate.

24. A method as recited in claim 18 wherein the one external plate is a luminescent faceplate, the second bonding area being formed on a connector ridge formed on the internal surface of the luminescent faceplate.

25. A method of fabricating a field emission display, comprising:

providing an emitter matrix on a cathode plate, the cathode plate having at least one electrically conductive first bonding area in electrical connection with the emitter matrix;

providing at least one external plate having an internal surface, at least one second bonding area being associated with the internal surface of the external plate;

providing a wire wedge bond onto at least one of the first and second bonding areas, the wire wedge bond having a tail of severed bond wire projecting from said wedge bond and said at least one bonding area;

positioning the cathode plate and the external plate with their first and second bonding areas facing one another in alignment, the projecting wire wedge bond tail being interposed between the first and second bonding areas; and

pressing the cathode plate and the external plate against each other, the wire wedge bond tail deforming between the first and second bonding areas to conductively bond therebetween.

26. A method as recited in claim 25 wherein the wire wedge bond tail is provided from the second bonding area.

27. A method as recited in claim 25 further comprising providing a discrete interconnecting wire extending from the second bond area to a location remote of the cathode plate.