Redundant conductor structures for thin film FET driven liquid crystal displays

[54] REDUNDANT CONDUCTOR STRUCTURES FOR THIN FILM FET DRIVEN LIQUID CRYSTAL DISPLAYS

[75] Inventor: Donald E. Castleberry, Schenectady, N.Y.

[73] Assignee: General Electric Company,

Schenectady, N.Y.

[21] Appl. No.: 487,4*2
[22] Filed: Mar. 2,1990

Related U.S. Patent Documents

Reissue of:

[64] Patent No.: 4,804,953

Issued: Feb. 14, 1989

Appl. No.: 97,247
Filed: Sep. 16,1987

U.S. Applications:

[63] Continuation of Ser. No. 756,640, Jul. 19, 1985, abandoned.

[51] Int. CI.' G09G 3/36

[52] U.S. CI 340/784; 340/719;

357/23.7; 359/59

[58] Field of Search 340/784, 718, 719;

350/333, 334; 357/41, 23.7, 71; 365/63 [56] References Cited

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Primary Examiner—Alvin E. Oberley

Assistant Examiner—Richard Hjerpe

Attorney, Agent, or Firm—Marvin Snyder; James C.

Davis, Jr.

[57] ABSTRACT

Redundancy is provided in the data and gate lines of the liquid crystal display device for improved reliability and greater fabrication yield. The data lines in particular are preferably fabricated in a multilayer structure with two conductive layers sandwiching a narrow insulating strip. The presence of the insulating strip permits the upper conductive line to be formed without step jumps which can exhibit a tendency for poor electrical connection. The upper and lower conductive layers of the data line are in contact for the length of the lower data line, contact being made on either side of the narrower insulating strip. Similar redundancy, without the necessity of providing an intermediary insulating layer is also provided for the gate lines. The redundancy provided in the present invention is particularly suitable for fabrication methods employed in thin film FET driven LCD devices.

56 Claims, 7 Drawing Sheets