US3900864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monolithic led displays
Assignee: AT&T Inc
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Filing: 1973-10-09
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Granted: 1975-08-19
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Expires: 1993-10-09
Abstract
Abstract The specification describes a process for defining the activedisplay regions in a monolithic electroluminescent display device. According to the process, the emitting regions of a semiconductor chip are electrically and optically isolated from the rest of the chip by laser machining. The chip remains intact with grooves extending below the junction to form active junction ''''islands.'''' The technique is advantageous with indirect band gap semiconductors, such as GaP, that can be viewed through the unmachined surface. In a preferred form the grooves are formed in a grid configuration. This structure has advantages in terms of cost and simplicity of manufacture.
Inventors
- 👤 Paul Daniel Dapkus
- 👤 Richard Wayne Dixon
- 👤 Walter Werner Weick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:03
CPC Classifications
H; H10; H10H; H10H29/00; H10H29/10; H10H20/00; H10H20/80
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
113 words
A light-emitting diode display device comprising a planar indirect band gap semiconductor chip, a large area, essentially planar, p-n junction formed within a major portion of the surface of the chip, a multiplicity of grooves formed into said major portion of the surface of the chip with a depth below the p-n junction and greater than the width of the grooves, each of said grooves defining an island on the chip and the islands defining the active light-emitting regions of the display, the said grooves providing a means for more effectively isolating the light-emitting regions, and electrical contacts to the islands and to the layer of the p-n junction remote from the surface.
Claim 2
Dependent Claim
113 words
A light-emitting diode display device comprising a planar indirect band gap semiconductor chip, a large area, essentially planar, p-n junction formed within a major portion of the surface of the chip, a multiplicity of grooves formed into said major portion of the surface of the chip with a depth below the p-n junction and greater than the width of the grooves, each of said grooves defining an island on the chip and the islands defining the active light-emitting regions of the display, the said grooves providing a means for more effectively isolating the light-emitting regions, and electrical contacts to the islands and to the layer of the p-n junction remote from the surface.
Claim 3
Dependent Claim
12 words
The device of claim 1 in which the semiconductor is gallium phosphide.
Claim 4
Dependent Claim
22 words
The device of claim 1 in which the grooves extend into the semiconductor surface at an angle with respect to the surface.
Claim 5
Dependent Claim
28 words
The device of claim 1 in which the semiconductor chip is bonded to a support substrate with the grooved side of the chip in contact with the substrate.
Claim 6
Dependent Claim
21 words
The device of claim 4 in which the electrical contacts are metallized regions that correspond to metallized regions on the substrate.
Claim 7
Dependent Claim
15 words
A light-emitting diode display comprising a plurality of semiconductor chips as defined in claim 1.
Claim 8
Dependent Claim
149 words
A light-emitting diode display device comprising a planar indirect band gap semiconductor chip, a large area, essentially planar, p-n junction formed within a major portion of the surface of the chip, a multiplicity of grooves formed into said major portion of the surface of the chip with a depth below the p-n junction and greater than the width of the grooves, the grooves comprising a first series of parallel grooves extending in one dimension along the surface and a second series of parallel grooves extending approximately orthogonal with respect to those of the first series thereby forming a multiplicity of islands of semiconductor regions, the said grooves providing a means for more effectively isolating the light-emitting regions, and electrical contacts to selected ones of those islands and to the layer of the p-n junction remote from the surface so as to form a desired pattern of active light-emitting regions.
Claim 9
Dependent Claim
149 words
A light-emitting diode display device comprising a planar indirect band gap semiconductor chip, a large area, essentially planar, p-n junction formed within a major portion of the surface of the chip, a multiplicity of grooves formed into said major portion of the surface of the chip with a depth below the p-n junction and greater than the width of the grooves, the grooves comprising a first series of parallel grooves extending in one dimension along the surface and a second series of parallel grooves extending approximately orthogonal with respect to those of the first series thereby forming a multiplicity of islands of semiconductor regions, the said grooves providing a means for more effectively isolating the light-emitting regions, and electrical contacts to selected ones of those islands and to the layer of the p-n junction remote from the surface so as to form a desired pattern of active light-emitting regions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |