Liquid crystal display assembly and method for reducing residual stresses

• US 6,356,334 B1
• Filed: 08/06/1998
• Issued: 03/12/2002
• Est. Priority Date: 08/06/1998
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Mathew, Ranjan J., Vikram, Seshadri
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, DUNG T
• Application Number:
  US09/130,631
• Time in Patent Office: 1,314 Days
• Field of Search: 349/58, 349/153, 349/152
• US Class Current: 349/153
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 1/133314 Back frames
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 2202/28 Adhesive materials or arrangements

Abstract

Apparatus are disclosed for Liquid Crystal Display (LCD) assemblies having a display device that is attached to a support substrate. The display device includes a die having a pixel array, and a transparent plate positioned over the die. An adhesive seal couples the die to the transparent plate. The seal together with the transparent plate and the die cooperate to define a sealed volume therebetween encompassing the pixel array. A liquid crystal material is disposed within the sealed volume. A support substrate is coupled to the transparent plate for support of the display device such that the die is substantially insulated from transmission of residual stresses induced by or acting upon the support substrate. Methods of reducing residual stresses in LCD assemblies are also provided.

Claims

1. A liquid crystal display assembly comprising:

a display device including;

a die having a pixel array;

a transparent plate;

an adhesive seal adhesively coupling the die to-the transparent plate, said adhesive seal, said transparent plate, and said die cooperating to define a sealed volume therebetween encompassing the pixel array; and

a liquid crystal material disposed within the sealed volume; and

a support substrate having said transparent plate cantilever mounted thereto for support of said display device by said support substrate such that said die is substantially insulated from transmission of residual stresses induced by or acting upon said support substrate.

2. A liquid crystal display assembly as defined in claim 1, wherein the support substrate includes a shoulder portion defining a cavity formed for receipt of said die therein the substrate shoulder portion being adapted to support said ledge portion of said transparent plate for support of said transparent plate and said die while said die remains substantially free of direct contact with said relatively rigid support substrate.

3. A liquid crystal display assembly as defined in claim 2, wherein said transparent plate cantilever mounted to said support substrate at a single point location of the shoulder portion and in lateral sliding support with opposed contact locations of the shoulder portion spaced-apart from the single point location.

4. A liquid crystal display assembly as defined in claim 3, wherein said transparent plate is cantilever mounted to said support substrate proximate a single peripheral side of the shoulder portion and in lateral sliding support with opposed contact locations of the shoulder portion spaced-apart from the single peripheral side.

5. The liquid crystal assembly of claim 1, wherein the transparent plate is coupled to the support substrate with an electrically conductive adhesive mounting.

6. A liquid crystal display assembly comprising:

a die having a pixel array, a top surface and an opposite undersurface;

a transparent plate;

an adhesive seal adhesively coupling the die to the transparent plate such that a ledge portion thereof extends beyond a peripheral edge portion of said die and said adhesive seal, said transparent plate, said adhesive seal, and said top surface of the die cooperating to define a sealed volume encompassing the pixel array;

a liquid crystal material disposed within the sealed volume; and

a relatively rigid support substrate mounted to said transparent plate in a manner such that said die remains substantially free of direct contact with said relatively rigid support substrate, said support substrate further including a base portion having a selected dimension which, during operational heating of the display assembly, effects predetermined bowing or warping forces on the transparent plate to modulate a net bowing or warping effect on the display assembly.

7. The liquid crystal display assembly of claim 6, wherein the support substrate includes a shoulder portion defining a cavity formed for receipt of said die therein, the substrate shoulder portion being adapted to support said ledge portion of said transparent plate for support of said transparent plate and said die while said die remains substantially free of direct contact with said relatively rigid support substrate.

8. The liquid crystal display assembly of claim 7, wherein the dimension varied is the thickness of said base.

9. The liquid crystal display assembly of claim 8, wherein the thickness of said base is selected to modulate a slight net positive bow upon the display assembly.

10. The liquid crystal display assembly of claim 8, wherein the thickness of the base is between about 1.0 mm to about 4.0 mm.

11. The liquid crystal display assembly of claim 6, wherein the transparent plate is coupled to the relatively rigid support substrate with an adhesive mounting.

12. The liquid crystal display assembly of claim 11, wherein the adhesive mounting is electrically conductive.

13. A method of modulating warping and bowing stresses in a liquid crystal display assembly, the method comprising:

providing a display device including a die having a pixel array, a top surface and an opposite undersurface;

a transparent plate with a ledge portion, an adhesive seal coupling the die to said transparent plate, and a liquid crystal material disposed within a sealed volume formed between the adhesive seal, the transparent plate, and the top surface of the die;

selecting a relatively rigid support substrate having a selected dimension to effect for predetermined warping and bowing forces, during operational heating of the display assembly, upon on the display device once coupled to said relatively rigid support substrate to modulate a net bowing or warping effect on the display assembly.

14. The method of claim 13, further including coupling the display device to the relatively rigid support substrate via the ledge portion of the transparent plate, wherein said die remains relatively free of substantial direct contact to said relatively rigid support substrate.

15. The method of claim 14, wherein the relatively rigid support substrate has a cavity formed and dimensioned for receipt of said die therein, said cavity having a base and a shoulder portion adapted to cooperate with said ledge portion of said transparent plate for support of said transparent plate.

16. The method of claim 14, wherein the predetermined dimension specification is a measure of thickness of the base.

17. The liquid crystal display assembly of claim 16, wherein said selecting includes choosing the thickness of said base to modulate a slight net positive bow upon the display assembly.

18. The method of claim 16, wherein the base is between about 1.0 mm to about 4.0 mm thick.