Thermal management in electronic displays

• US RE41,914 E1
• Filed: 07/03/2007
• Issued: 11/09/2010
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Transpacific Infinity LLC
• Original Assignee: Transpacific Infinity LLC
• Inventors: Palanisamy, Ponnusamy
• Primary Examiner(s): Ton; Toan
• Assistant Examiner(s): QUARTERMAN, KEVIN J
• Application Number:
  US11/825,328
• Time in Patent Office: 1,225 Days
• Field of Search: 313/484, 313/502, 313/504, 313/506, 313/512, 315/169.1, 315/169.3, 315/169.4, 345/76, 345/84, 345/87, 349/153, 349/73, 349/74
• US Class Current: 313/484
• CPC Class Codes: G02F 1/13336 Combining plural substrates to produce large-area displays, e.g. tiled displays
• CPC Class Codes: G02F 1/133382 Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: H01J 2211/66 Cooling arrangements cooling or supporting means not being part of the tube H05K
• CPC Class Codes: H01J 2329/002 Cooling means
• CPC Class Codes: H01J 29/006 Arrangements for eliminating unwanted temperature effects
• CPC Class Codes: H01L 2251/5338 Flexible OLED
• CPC Class Codes: H01L 27/3288 Wiring lines
• CPC Class Codes: H01L 27/3293 Tiled displays
• CPC Class Codes: H01L 51/5246 characterised by the peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H01L 51/529 Arrangements for heating or cooling
• CPC Class Codes: H05K 1/0203 Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 2201/10128 Display
• CPC Class Codes: H05K 3/0058 Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: H05K 3/3436 having an array of bottom contacts, e.g. pad grid array or ball grid array components
• CPC Class Codes: H05K 7/20963 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20972 takes precedence

Abstract

A display having improved thermal management and a method for producing the display are disclosed. The display includes a pixel structure adjacent a front panel with thermo-mechanical elements extending between a back panel and the pixel structure to dissipate heat generated by the pixel structure.

Claims

1. A display comprising:

a front panel;

a back panel spaced from the front panel, the front and back panels defining a space therebetween;

at least one pixel structure adjacent the front panel in the space between the front and back panels;

a plurality of electrical connections extending between the back panel and the at least one pixel structure; and

a plurality of thermo-mechanical elements extending between the back panel and the at least one pixel structure to dissipate heat from the at least one pixel structure toward the back panel, wherein at least one of the plurality of thermo-mechanical elements is positioned between adjacent pixel structures of the at least one pixel structure.

2. The display of claim 1, wherein the plurality of thermo-mechanical elements are separate from the plurality of electrical connections.

3. The display of claim 1, wherein the plurality of thermo-mechanical elements comprise a material selected from a group consisting of InSn solder and silver-filled epoxy adhesive.

4. The display of claim 1, wherein the plurality of electrical connections are formed from materials used to form the plurality of thermo-mechanical elements.

5. The display of claim 1, wherein at least one of the plurality of thermo-mechanical elements is larger than one or more of the plurality of electrical connections.

6. The display of claim 1, wherein the back panel comprises a thermally conductive material for dissipating at least the heal received at the back panel via the plurality of thermo-mechanical elements.

7. The display of claim 1, wherein the back panel is formed from a material selected from a group consisting of alumina and aluminum nitride.

8. The display of claim 1, further comprising:

an underfill encapsulant filling the space between the front and back panels to further dissipate heat from the at least one pixel structure toward the back panel.

9. The display of claim 8, wherein the underfill encapsulant is an alumina filled epoxy.

10. The display of claim 8, wherein the underfill encapsulant includes a filler selected from a group consisting of diamond, BN, AlN, BeO, and SiC.

11. The display of claim 1, wherein the at least one pixel structure comprises a display material selected from a group consisting of organic light emitting diodes (OLED), light emitting diodes, field emissive elements, plasma elements, cathodoluminescent elements, end and bistable, reflective cholesteric (BRC) liquid crystal elements.

12. An electronic display comprising:

a front panel;

a back panel spaced from the front panel, the front and back panels defining a space therebetween;

at least one pixel structure having a top surface adjacent the front panel and a bottom surface, each of the at least one pixel structure having a first electrode on the top surface and a second electrode on the bottom surface;

a first electrical connection via extending between the back panel and the first electrode of one of the at least one pixel structure;

a second electrical connection via extending between the back panel and the second electrode of the one of the at least one pixel structure; and

at least one thermo-mechanical via extending between the back panel and the one of the at least one pixel structure to dissipate heat from the one of the at least one pixel structure to the back panel, wherein the at least one thermo-mechanical via is positioned between adjacent pixel structures of the at least one pixel structure.

13. The display of claim 12, wherein the at least one thermo-mechanical via is electrically isolated from the first and second electrodes.

14. The display of claim 12, wherein the at least one pixel structure comprises a display material selected from a group consisting of organic light emitting diodes (OLED), light emitting diodes, field emissive elements, plasma elements, cathodoluminescent elements, and bistable, reflective cholesteric (BRC) liquid crystal elements.

15. The display of claim 12, wherein the at least one thermo-mechanical via is formed from a material selected from a group consisting of InSn solder and silver-filled epoxy adhesive.

16. The display of claim 12, wherein the back panel comprises a thermally conductive material for dissipating at least the heat received at the back panel via the at least one thermo-mechanical via.

17. The display of claim 12, wherein the back panel is formed from a material selected from a group consisting of alumina and aluminum nitride.

18. The display of claim 12, further comprising:

an underfill encapsulant filling the space between the front and back panels to further dissipate heat from the at least one pixel structure toward the back panel.

19. The display of claim 18, wherein the underfill encapsulant is an alumina filled epoxy.

20. The display of claim 18, wherein the underfill encapsulant includes a filler selected from a group consisting of diamond, BN, AlN, BeO, and SiC.

21. A display comprising:

a front panel;

a back panel spaced from the front panel;

at least one pixel structure adjacent to the front panel; and

a plurality of thermo-mechanical elements extending between the back panel and the at least one pixel structure and configured to dissipate heat from the at least one pixel structure toward the back panel, wherein at least one of the plurality of thermo-mechanical elements is positioned between the at least one pixel structure and another pixel structure positioned adjacent to the at least one pixel structure.

22. The display of claim 21, further comprising a plurality of electrical connections extending between the back panel and the at least one pixel structure.

23. The display of claim 22, wherein the plurality of thermo-mechanical elements are separate from the plurality of electrical connections.

24. The display of claim 22, wherein the plurality of electrical connections and the plurality of thermo-mechanical elements are formed from the same material.

25. The display of claim 22, wherein at least one of the plurality of thermo-mechanical elements is larger than at least one of the plurality of electrical connections.

26. The display of claim 22, wherein a second thermo-mechanical element of the plurality of thermo-mechanical elements is positioned adjacent to at least one of the plurality of electrical connections.

27. The display of claim 22, wherein a second thermo-mechanical element of the plurality of thermo-mechanical elements is positioned under an active pixel area of the at least one pixel structure.

28. The display of claim 21, wherein the at least one of the plurality of thermo-mechanical elements is further configured to dissipate heat from a display module toward a circuit module, and wherein the display module includes the at least one pixel structure.

29. The display of claim 21, wherein the plurality of thermo-mechanical elements comprise a material selected from the group consisting of InSn solder and silver-filled epoxy adhesive.

30. The display of claim 21, wherein the back panel comprises a thermally-conductive material configured to dissipate heat received at the back panel via the plurality of thermo-mechanical elements.

31. The display of claim 21, wherein the back panel comprises a material selected from the group consisting of alumina and aluminum nitride.

32. The display of claim 21, further comprising an encapsulant filling a space between the front and back panels and configured to dissipate heat from the at least one pixel structure.

33. The display of claim 32, wherein the encapsulant is an epoxy comprising alumina.

34. The display of claim 32, wherein the encapsulant comprises a filler selected from the group consisting of diamond, boron nitride, aluminum nitride, beryllium oxide, and silicon carbide.

35. The display of claim 21, wherein the at least one pixel structure comprises a display material selected from the group consisting of organic light emitting diodes (OLED), light emitting diodes, field emissive elements, plasma elements, cathodoluminescent elements, and bistable reflective cholesteric (BRC) liquid crystal elements.

36. An electronic display comprising:

a front panel;

a back panel spaced apart from the front panel;

at least one pixel structure including a first surface having a first electrode and a second surface having a second electrode, wherein the first surface is positioned adjacent to the front panel;

a first conductive via extending between the back panel and the first electrode;

a second conductive via extending between the back panel and the second electrode; and

at least one thermo-mechanical via extending between the back panel and the at least one pixel structure and configured to dissipate heat from the at least one pixel structure, wherein the at least one thermo-mechanical via is positioned between the at least one pixel structure and another pixel structure positioned adjacent to the at least one pixel structure.

37. The display of claim 36, wherein the at least one thermo-mechanical via is electrically isolated from the first electrode and the second electrode.

38. The display of claim 36, wherein the at least one pixel structure comprises a display material selected from the group consisting of organic light emitting diodes (OLED), light emitting diodes, field emissive elements, plasma elements, cathodoluminescent elements, and bistable reflective cholesteric (BRC) liquid crystal elements.

39. The display of claim 36, wherein the at least one thermo-mechanical via is formed from a material selected from the group consisting of InSn solder and silver-filled epoxy adhesive.

40. The display of claim 36, wherein the back panel comprises a thermally conductive material configured to dissipate heat received at the back panel from the at least one thermo-mechanical via.

41. The display of claim 36, wherein the back panel comprises alumina or aluminum nitride.

42. The display of claim 36, further comprising an encapsulant filling a space between the front and the back panel and configured to dissipate heat from the at least one pixel structure.

43. The display of claim 42, wherein the encapsulant is an epoxy comprising alumina.

44. The display of claim 42, wherein the encapsulant comprises a filler selected from the group consisting of diamond, boron nitride, aluminum nitride, beryllium oxide, and silicon carbide.

45. The display of claim 36, further comprising a display material deposited onto the first electrode to define an active area of the at least one pixel structure.

46. An apparatus comprising:

a display including a front panel and a back panel, wherein the front panel and the back panel are spaced apart;

at least one pixel structure having a surface adjacent to the front panel; and

at least one thermo-mechanical element extending between the back panel and the at least one pixel structure and configured to conduct heat from the at least one pixel structure to the back panel, wherein the at least one thermo-mechanical element is positioned between the at least one pixel structure and another pixel structure positioned adjacent to the at least one pixel structure.

47. The apparatus of claim 46, further comprising a plurality of electrical connections extending between the back panel and the at least one pixel structure.

48. The apparatus of claim 46, wherein the back panel comprises a thermally-conductive material configured to dissipate heat received at the back panel via the at least one thermo-mechanical element.

49. The apparatus of claim 46, further comprising an underfill encapsulant provided between the front panel and the back panel and configured to direct heat from the at least one pixel structure toward the back panel.

50. The apparatus of claim 46, wherein the at least one thermo-mechanical element is a via.