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Title:
PRINTED ELECTRICAL DEVICE HAVING A POWER SWITCH WITH A HIGH OHMIC "OFF" STATE, AND METHODS OF MAKING AND USING THE SAME
Document Type and Number:
WIPO Patent Application WO/2018/065855
Kind Code:
A1
Abstract:
A printed electronic display device and methods of manufacturing and using the same are disclosed. The device includes a substrate (200) having a plurality of traces (230, 232) thereon, a printed integrated circuit (210), a battery (220), a switch (240, 242), and a display. A first one of the traces (230) has a first end and a second one of the traces (232) has a second end in proximity to the first end. The printed integrated circuit is electrically connected to the first trace. The battery is electrically connected to the second trace. The switch has an ON state and an OFF state. The ON state electrically connects the first and second ends of the first and second traces, and the OFF state imparts a high ohmic resistance between the first and second ends of the first and second traces. The display receives at least one output from the printed integrated circuit.

Inventors:
HAGEL OLLE (SE)
ANDERSSON NIKLAS (SE)
BROMS PER (SE)
XIE LI (SE)
DANESTIG MAGNUS (SE)
Application Number:
PCT/IB2017/055921
Publication Date:
April 12, 2018
Filing Date:
September 27, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
THIN FILM ELECTRONICS ASA (NO)
International Classes:
H05K1/16; G09F3/20; H01M6/40; H05K1/02; H05K1/03; H05K1/14; H05K1/18; H05K3/12
Foreign References:
US20160238201A12016-08-18
US20040156418A12004-08-12
US20110241446A12011-10-06
US20060227523A12006-10-12
US7687327B22010-03-30
US7767520B22010-08-03
US8796125B22014-08-05
US24346005A2005-10-03
US201514870561A2015-09-30
Attorney, Agent or Firm:
MAHAN, Theresa et al. (US)
Download PDF:
Claims:
CLAIMS

claimed is:

An electronic display device, comprising:

a) a substrate having a plurality of traces thereon, a first one of said traces having a first end and a second one of said traces having a second end in proximity to the first end;

b) a printed integrated circuit electrically connected to the first trace;

c) a battery electrically connected to the second trace;

d) a switch having an ON state and an OFF state, wherein the ON state electrically connects the first and second ends of the first and second traces, and the OFF state imparts a high ohmic resistance between the first and second ends of the first and second traces; and

e) a display receiving at least one output from the printed integrated circuit.

The device of claim 1, further comprising one or more sensors electrically connected to the printed integrated circuit.

The device of claim 2, wherein at least one of said one or more sensors is also electrically connected to the battery.

The device of claim 2 or 3, comprising a plurality of said sensors, each of which is electrically connected to the printed integrated circuit.

The device of claim 2 or 3, wherein each of said one or more sensors is selected from the group consisting of chemical sensors, continuity sensors, temperature sensors, humidity sensors and timers.

The device of claim 1, 2, 3 or 4, comprising a plurality of said displays, each of which is electrically connected to the printed integrated circuit.

The device of claim 6, wherein each of said display(s) is configured to indicate a state of a corresponding one of said sensor (s).

The device of claim 1, 6 or 7, wherein each of said display(s) is selected from the group consisting of electrochromic displays, segment displays, liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, and electroluminescent displays (ELDs).

The device of claim 1, 2, 3 or 6, wherein said printed integrated circuit comprises a plurality of layers, and one or more layers of said printed integrated circuit comprises a printed conductor, semiconductor or insulator.

10. The device of claim 9, wherein a first one of said plurality of layers of said printed integrated circuit comprises said printed semiconductor.

11. The device of claim 10, wherein a second one of said plurality of layers of said printed integrated circuit comprises said printed insulator.

12. The device of claim 11, wherein a third one of said plurality of layers of said printed integrated circuit comprises said printed conductor.

13. The device of claim 9, wherein all or substantially all of said plurality of layers of said printed integrated circuit comprise a printed material.

14. The device of claim 1, 2, 3, 6 or 9, wherein said battery comprises a plurality of layers, and one or more layers of said battery comprises a printed material.

15. The device of claim 14, wherein a plurality of layers of said battery comprise a printed layer.

16. The device of claim 14 or 15, wherein the battery comprises a first current collector, one of a cathode and an anode in contact with the first current collector, an electrolyte in contact with said one of said cathode and said anode, the other of said cathode and said anode in contact with said electrolyte, and a second current collector in contact with said other of said cathode and said anode.

17. The device of claim 1, 2, 3, 6, 9 or 14, wherein said switch is an OFF-to-ON switch.

18. The device of claim 1, 2, 3, 6, 9, 14 or 17, wherein said switch comprises a conductive adhesive and a pull tab connected to an insulating liner or tape between the conductive adhesive and the first and second ends of the first and second traces.

19. The device of claim 18, wherein said switch is placed in the ON state by removal of the pull tab and compression of the conductive adhesive towards the first and second ends of the first and second traces.

20. The device of claim 1, 2, 3, 6, 9, 14 or 17, wherein the switch comprises a metal dome electrically connected to one of the first and second ends of the first and second traces.

21. The device of claim 20, wherein said metal dome is mechanically stable in each of the ON and OFF states.

22. The device of claim 20 or 21, wherein said metal dome further comprises a conductive adhesive on an underside thereof.

23. The device of claim 20, 21 or 22, wherein compression of said metal dome causes said metal dome to electrically contact the other of the first and second ends of the first and second traces.

24. The device of claim 18, 19 or 22, wherein the conductive adhesive is an anisotropic conductive adhesive.

25. The device of claim 1, 2, 3, 6, 9, 14, 17 or 20, wherein said substrate is flexible.

26. The device of claim 25, wherein said substrate comprises a plastic sheet or film, paper, a metal foil or film, or a combination thereof, and has an electrically insulating surface.

27. The device of claim 25 or 26, wherein said substrate comprises a flexible material with an underlay in contact therewith.

28. The device of claim 25, 26 or 27, wherein said substrate comprises polyethylene terephthalate (PET).

29. The device of claim 1, 2, 3, 6, 9, 14, 17, 20 or 25, further comprising a graphical and/or protective overlay on an outermost surface of the device.

30. The device of claim 29, wherein portion(s) of the graphical and/or protective overlay over said display(s) is/are transparent or translucent.

31. The device of claim 29 or 30, further comprising a spacer between the substrate and the graphical and/or protective overlay.

32. The device of claim 31, wherein the spacer includes a cutout, trench or opening in locations corresponding to each of said display(s), said printed integrated circuit, said battery and said switch.

33. A method of making a printed electronic device, comprising:

a) forming a printed integrated circuit, a battery, one or more displays and a plurality of traces on a first substrate, wherein the printed integrated circuit is electrically connected to a first one of said traces, the battery is electrically connected to a second one of said traces, a first end of the first trace is in proximity to a second end of the second trace, and the one or more displays is/are configured to receive at least one output from the printed integrated circuit; and

b) electrically connecting a switch having an ON state and an OFF state to one of the first and second ends of the first and second traces, wherein the ON state electrically connects the first and second ends of the first and second traces, and the OFF state imparts a high ohmic resistance between the first and second ends of the first and second traces.

34. The method of claim 33, further comprising covering the printed integrated circuit, the battery, the one or more displays, the plurality of traces and the switch with a graphical and/or protective overlay.

35. The method of claim 34, wherein portion(s) of the graphical and/or protective overlay over said display(s) is/are transparent or translucent.

36. The method of claim 34 or 35, further comprising forming a spacer on one of the first substrate and the graphical and/or protective overlay prior to covering the printed integrated circuit, the battery, the one or more displays, the plurality of traces and the switch with a graphical and/or protective overlay.

37. The method of claim 36, wherein the spacer includes a cutout, trench or opening in locations corresponding to each of said one or more displays, said printed integrated circuit, said battery and said switch.

38. The method of claim 33, further comprising forming one or more sensors on the first substrate, wherein each of the one or more sensors is electrically connected to the printed integrated circuit.

39. The method of claim 38, wherein at least one of said one or more sensors is also electrically connected to the battery.

40. The method of claim 38 or 39, comprising a plurality of said sensors, each of which is electrically connected to the printed integrated circuit.

41. The method of claim 38 or 39, wherein each of said one or more sensors is selected from the group consisting of chemical sensors, continuity sensors, temperature sensors, humidity sensors and timers.

42. The method of claim 38, 39 or 40, comprising a plurality of said displays, each of which is electrically connected to the printed integrated circuit.

43. The method of claim 42, wherein each of said display(s) is configured to indicate a state of a corresponding one of said sensor(s).

44. The method of claim 33, comprising a plurality of said displays, each of which is electrically connected to the printed integrated circuit.

45. The method of claim 33, 42, 43 or 44, wherein each of said display(s) is selected from the group consisting of electrochromic displays, segment displays, liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, and electroluminescent displays (ELDs).

46. The method of claim 33, 38, 39 or 42, wherein said printed integrated circuit comprises a plurality of layers, and one or more of said layers of said printed integrated circuit are formed by printing a conductor, semiconductor or insulator material or precursor.

47. The method of claim 46, wherein forming a first one of said layers of said printed integrated circuit comprises printing said semiconductor material or precursor.

48. The method of claim 47, wherein forming a second one of said plurality of layers of said printed integrated circuit comprises printing said insulator material or precursor.

49. The method of claim 48, wherein forming a third one of said plurality of layers of said printed integrated circuit comprises said printing conductor material or precursor.

50. The method of claim 46, wherein forming all or substantially all of said plurality of layers of said printed integrated circuit comprises printing the conductor, semiconductor and insulator materials or precursors.

51. The method of claim 33 or 46, further comprising forming said printed integrated circuit on a second substrate, and forming said printed integrated circuit on said first substrate comprises attaching the second substrate to said first substrate.

52. The method of claim 33, 38, 39, 42, 46 or 51, wherein said battery comprises a plurality of layers, and one or more layers of said battery is formed by printing.

53. The method of claim 52, comprising forming said plurality of layers of said battery by printing.

54. The method of claim 33, 51 or 52, further comprising forming said battery on a third substrate, and forming said battery on said first substrate comprises attaching the third substrate to said first substrate.

55. The method of claim 33 or 52, wherein the battery comprises a first current collector, one of a cathode and an anode in contact with the first current collector, an electrolyte in contact with said one of said cathode and said anode, the other of said cathode and said anode in contact with said electrolyte, and a second current collector in contact with said other of said cathode and said anode.

56. The method of claim 33, 38, 39, 42, 46 or 52, wherein said switch is an OFF-to-ON switch.

57. The method of claim 56, wherein said switch comprises a conductive adhesive and an insulating liner or tape thereon, the insulating liner or tape having a pull tab connected thereto, and the method further comprises applying the conductive adhesive to one of the overlay and the spacer in a location corresponding to or overlapping the first and second ends of the first and second traces.

58. The method of claim 57, wherein said switch is placed in the ON state by removal of the pull tab and compression of the conductive adhesive towards the first and second ends of the first and second traces.

59. The method of claim 56, wherein the switch comprises a metal dome, and the method further comprises electrically connecting the metal dome to one of the first and second ends of the first and second traces.

60. The method of claim 59, wherein said metal dome is mechanically stable in each of the ON and OFF states.

61. The method of claim 59 or 60, wherein the method further comprises applying a conductive adhesive on or to an underside of the metal dome.

62. The method of claim 59, 60, or 61, wherein compression of said metal dome causes said metal dome to electrically contact the other of the first and second ends of the first and second traces.

63. The method of claim 57, 58 or 61, wherein the conductive adhesive is an anisotropic conductive adhesive.

64. The method of claim 33, 38, 39, 42, 46, 52 or 56, wherein said substrate is flexible.

65. The method of claim 64, wherein said substrate comprises a plastic sheet or film, paper, a metal foil or film, or a combination thereof, and has an electrically insulating surface.

66. The method of claim 64 or 65, wherein said substrate comprises a flexible material with an underlay in contact therewith.

67. The method of claim 64, 65 or 66, wherein said substrate comprises polyethylene terephthalate (PET).

68. A method of operating an electronic display device, comprising:

a) electrically connecting a first end of a first trace on a substrate and a second end of a second trace on said substrate using a switch having an ON state and an OFF state, wherein the second end of the second trace is in proximity to the first end of the first trace, a printed integrated circuit is electrically connected to the first trace, a battery is electrically connected to the second trace, the ON state of the switch electrically connects the first and second ends of the first and second traces, and the OFF state of the switch imparts a high ohmic resistance between the first and second ends of the first and second traces; and b) displaying information on a display receiving at least one output from the printed integrated circuit.

69. The method of claim 68, wherein said switch is an OFF-to-ON switch.

70. The method of claim 68 or 69, wherein said switch comprises a conductive adhesive and a pull tab connected to an insulating liner or tape between the conductive adhesive and the first and second ends of the first and second traces.

71. The method of claim 70, wherein said switch is placed in the ON state by removal of the pull tab and compression of the conductive adhesive towards the first and second ends of the first and second traces.

72. The method of claim 68, wherein the switch comprises a metal dome electrically connected to one of the first and second ends of the first and second traces.

73. The method of claim 72, wherein said metal dome is mechanically stable in each of the ON and OFF states.

74. The method of claim 72 or 73, wherein said metal dome further comprises a conductive adhesive on an underside thereof.

75. The method of claim 72, 73 or 74, wherein compression of said metal dome causes said metal dome to electrically contact the other of the first and second ends of the first and second traces.

76. The method of claim 70, 71 or 74, wherein the conductive adhesive is an anisotropic conductive adhesive.

77. The method of claim 68 or 69, further comprising determining a state of one or more sensors electrically connected to the printed integrated circuit.

78. The method of claim 68, 69 or 77, wherein at least one of said one or more sensors is also electrically connected to the battery.

79. The method of claim 68, 69, 77 or 78, comprising determining the state of a plurality of said sensors, each of which is electrically connected to the printed integrated circuit.

80. The method of claim 68, 69, 77, 78 or 79, wherein each of said sensor(s) is selected from the group consisting of chemical sensors, continuity sensors, temperature sensors, humidity sensors and timers.

81. The method of claim 68, 69, 77, 78 or 79, comprising displaying information on each of a plurality of said displays, each of which is electrically connected to the printed integrated circuit.

82. The method of claim 81, wherein each of said display(s) is configured to indicate a state of a corresponding one of said sensor(s).

83. The method of claim 68, 69, 77 or 81, wherein each of said display(s) is selected from the group consisting of electrochromic displays, segment displays, liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, and electroluminescent displays (ELDs).

84. The method of claim 68, 69, 77 or 81, wherein said printed integrated circuit comprises a plurality of layers, and one or more layers of said printed integrated circuit comprises a printed conductor, semiconductor or insulator.

85. The method of claim 84, wherein all or substantially all of said plurality of layers of said printed integrated circuit comprise a printed material.

86. The method of claim 68, 69, 77, 81 or 84, wherein said battery comprises a plurality of layers, and one or more layers of said battery comprises a printed material.

87. The method of claim 86, wherein a plurality of layers of said battery comprise a printed layer.

88. The method of claim 85 or 86, wherein the battery comprises a first current collector, one of a cathode and an anode in contact with the first current collector, an electrolyte in contact with said one of said cathode and said anode, the other of said cathode and said anode in contact with said electrolyte, and a second current collector in contact with said other of said cathode and said anode.

89. The method of claim 68, 69, 77, 81, 84 or 86, wherein said substrate is flexible.

90. The method of claim 89, wherein said substrate comprises a plastic sheet or film, paper, a metal foil or film, or a combination thereof, and has an electrically insulating surface.

91. The method of claim 89 or 90, wherein said substrate comprises a flexible material with an underlay in contact therewith.

92. The method of claim 89, 90 or 91, wherein said substrate comprises polyethylene terephthalate (PET).

93. The method of claim 68, 69, 77, 81, 84, 86 or 89, further comprising a graphical and/or protective overlay on an outermost surface of the method.

94. The method of claim 93, wherein portion(s) of the graphical and/or protective overlay over said display(s) is/are transparent or translucent.

95. The method of claim 93 or 94, further comprising a spacer between the substrate and the graphical and/or protective overlay.

96. The method of claim 95, wherein the spacer includes a cutout, trench or opening in locations corresponding to each of said display(s), said printed integrated circuit, said battery and said switch.

Description:
PRINTED ELECTRICAL DEVICE HAVING A POWER SWITCH WITH A HIGH OHMIC "OFF" STATE, AND METHODS OF MAKING AND USING THE SAME

CROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit of U.S. Provisional Patent Application No.

62/405,738, filed on October 7, 2016, incorporated herein by reference as if fully set forth herein.

FIELD OF THE INVENTION

[0002] The present invention generally relates to structures and methods for controlling power consumption in printed integrated circuits and other printed electrical devices. More specifically, embodiments of the present invention pertain to a switch or other mechanism to turn a printed electronic device on (and optionally off), and methods of making and using the same.

DISCUSSION OF THE BACKGROUND

[0003] Printed integrated circuits and other printed electronic devices may include a power management circuit or other power management scheme that does not fully turn off the integrated circuit or printed electronic device. In such cases, if the printed integrated circuit or other printed electronic device is powered by a battery, the stand-by leakage of the printed integrated circuit or other printed electronic device may drain the battery during storage of the integrated circuit or device.

[0004] In certain battery-powered electronic devices (e.g., battery-operated toys), it is common to insert a pull-tab between the battery (or batteries) and an electrical contact in the battery compartment to reduce or prevent draining electrical charge from the battery/batteries. The electrical contact is often a metal plate or disc that provides electric power from the battery or batteries to circuitry and/or a motor inside the device. The pull-tab is held in place by a spring in the battery compartment that applies a force to the battery or batteries in the direction of the electrical contact. Upon removal of the pull-tab, the spring ensures that electrical contact is made between the battery and the electrical contact.

[0005] Alternatively, a metal dome switch is used in many applications (e.g., small, mobile, battery-powered, handheld electronic devices) to fully connect or disconnect a battery or circuit element in the electronic device. Such dome switches are particularly useful in devices where a low profile is desired.

[0006] However, printed electronic devices typically include an integrated battery (e.g., a thin film or printed battery) without a spring or other mechanism for ensuring contact between a terminal of the battery and a lead or trace to the electrical circuitry. Therefore, a need is felt for a switch with a very high ohmic OFF state for printed integrated circuits and other printed electronic devices such as smart labels and printed sensors, as well as a low cost, high-volume solution for a reliable power-on switch for such smart labels and sensors.

[0007] This "Discussion of the Background" section is provided for background information only. The statements in this "Discussion of the Background" are not an admission that the subject matter disclosed in this "Discussion of the Background" section constitutes prior art to the present disclosure, and no part of this "Discussion of the Background" section may be used as an admission that any part of this application, including this "Discussion of the Background" section, constitutes prior art to the present disclosure.

SUMMARY OF THE INVENTION

[0008] The present invention relates to printed electronic display devices such as smart labels and flexible sensors, and methods of manufacturing and using the same.

[0009] In one aspect, the present invention relates to a printed electronic display device that includes a substrate having a plurality of traces thereon, a printed integrated circuit, a battery, a switch, and a display. A first one of the traces has a first end and a second one of the traces has a second end in proximity to the first end. The printed integrated circuit is electrically connected to the first trace. The battery is electrically connected to the second trace. The switch has an ON state and an OFF state. The ON state electrically connects the first and second ends of the first and second traces, and the OFF state imparts a high ohmic resistance between the first and second ends of the first and second traces. The display receives at least one output from the printed integrated circuit.

[0010] In another aspect, the present invention relates to a method of making a printed electronic device, comprising forming a printed integrated circuit, a battery, one or more displays and a plurality of traces on a substrate, and electrically connecting a switch having an ON state and an OFF state to an end of one of two of the traces. The printed integrated circuit is electrically connected to one of the two traces, and the battery is electrically connected to the other one of the two traces. The two traces each have an end in proximity to the end of the other trace. The ON state of the switch electrically connects the ends of the two traces, and the OFF state imparts a high ohmic resistance between the ends of the two traces. The display (s) are configured to receive at least one output from the printed integrated circuit.

[0011] Yet another aspect of the invention relates to a method of operating an electronic display device, comprising electrically connecting a first end of a first trace on a substrate and a second end of a second trace on said substrate using a switch having an ON state and an OFF state, and displaying information on a display receiving at least one output from a printed integrated circuit. The second end of the second trace is in proximity to the first end of the first trace. The printed integrated circuit is electrically connected to the first trace, and a battery is electrically connected to the second trace. The ON state of the switch electrically connects the first and second ends of the first and second traces, and the OFF state of the switch imparts a high ohmic resistance between the first and second ends of the first and second traces.

[0012] The present invention advantageously provides significantly longer shelf life for smart labels, display devices and other printed electronic devices that are powered by an on-board battery. These and other advantages of the present invention will become readily apparent from the detailed description of various embodiments below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is an exemplary optical display device with one or more sensors according to embodiments of the present invention.

[0014] FIG. 2 is a showing an exemplary schematic for the optical display device of

FIG. 1 according to embodiments of the present invention.

[0015] FIGS. 3A-H are cross-sectional and plan views showing exemplary structures in various stages of an exemplary process for making an exemplary optical display device according to embodiments of the present invention.

[0016] FIG. 4 shows a second exemplary optical display device with one or more sensors according to embodiments of the present invention.

[0017] FIG. 5 is a cross-sectional view of an exemplary metal dome switch according to one or more embodiments of the present invention.

[0018] FIGS. 6A-C are plan views of exemplary metal dome switches according to embodiments of the present invention.

[0019] FIG. 7 shows an alternative layout for another exemplary electronic display device according to embodiments of the present invention.

[0020] FIG. 8 is a cross-sectional view of a prototype electronic display device according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0021] Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the following embodiments, it will be understood that the descriptions are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents that may be included within the spirit and scope of the invention. Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to unnecessarily obscure aspects of the present invention. Furthermore, it should be understood that the possible permutations and combinations described herein are not meant to limit the invention. Specifically, variations that are not inconsistent may be mixed and matched as desired.

[0022] The technical proposal(s) of embodiments of the present invention will be fully and clearly described in conjunction with the drawings in the following embodiments. It will be understood that the descriptions are not intended to limit the invention to these embodiments. Based on the described embodiments of the present invention, other embodiments can be obtained by one skilled in the art without creative contribution and are in the scope of legal protection given to the present invention.

[0023] Furthermore, all characteristics, measures or processes disclosed in this document, except characteristics and/or processes that are mutually exclusive, can be combined in any manner and in any combination possible. Any characteristic disclosed in the present specification, claims, Abstract and Figures can be replaced by other equivalent characteristics or characteristics with similar objectives, purposes and/or functions, unless specified otherwise.

[0024] For the sake of convenience and simplicity, the terms "tape" and "liner" are, in general, interchangeable and may be used interchangeably herein, but are generally given their art-recognized meanings. Wherever one such term is used, it also encompasses the other terms. In addition, for convenience and simplicity, the terms "part," "portion," and "region" may be used interchangeably but these terms are also generally given their art- recognized meanings. Furthermore, the terms "connected to," "in connection with," and grammatical variations thereof include both direct and direct connections, unless the context of its use clearly indicates otherwise. Also, unless indicated otherwise from the context of its use herein, the terms "known," "fixed," "given," "certain" and "predetermined" generally refer to a value, quantity, parameter, constraint, condition, state, process, procedure, method, practice, or combination thereof that is, in theory, variable, but is typically set in advance and not varied thereafter when in use.

[0025] The present invention advantageously enables electronic display devices manufactured using printing technology and/or made on a flexible substrate to have a dramatically longer shelf life, from on the order of weeks or a few months to a year or longer. Due to the increased battery performance during use, the present display device can enjoy improved performance and increased reliability, particularly when the present display device also includes one or more sensors. These and other advantages of the present invention will become more readily apparent from the discussion of various embodiments below.

An Exemplary Printed Electronic Device with a Reliable Power-on Mechanism Having a High Ohmic OFF State

[0026] In one aspect, the present invention concerns a printed electronic device with a reliable power-on mechanism having a high ohmic OFF state. For example, FIG. 1 is a plan view of an exemplary printed electronic display device 10 having one or more sensors thereon (not shown in FIG. 1). The display device 10 includes a power-on button or region

20, a plurality of display regions 30, 32 and 34, a plurality of graphic areas or regions 40, 42,

44 and 46, and a pull tab 54. The display device 10 also includes a battery and an integrated circuit (either or both of which may be printed and/or formed by thin-film processing), but these components are not visible through the exterior of the display device 10. The display device 10 may be rigid (e.g., a card-type device) or flexible (e.g., a label applied to a commercial product or to packaging or a container therefor). In some variations, the display device 10 may have dimensions similar to those of a credit card (e.g., a length of from 6 to 12 cm, a width of from 4 to 8 cm, and a thickness of from 0.5 to 2 mm, or any values or ranges of values therein), although it may have one or more dimensions that are not similar to a credit card.

[0027] In various embodiments, the display regions 30, 32 and 34 display information from one or more sensors and/or the integrated circuit. For example, the first display region 30 may display information indicating that the device 10 is on or off (e.g., when the device 10 is on, a symbol such as an "X" or a check mark may appear in the first display region 30), the second display region 32 may display information indicating a state of a first sensor, and the third display region 34 may display information indicating a state of a second sensor.

[0028] The first and second sensors may be independently selected from chemical sensors, continuity sensors, temperature sensors, humidity sensors, timers, etc. In various examples, the states of a chemical sensor may correspond to the presence of at least a threshold concentration of a predetermined chemical (e.g., carbon monoxide, carbon dioxide, ozone, dioxygen, a nitrogen oxide, ethanol, etc.) or less than the threshold concentration of the chemical. A continuity sensor may detect tampering with a package or container, or determine whether a product within a package or container on which the continuity sensor is placed is authentic (e.g., factory-sealed). States of a continuity sensor may include "SEALED," "AUTHENTIC," "OPEN," "PARTIALLY OPEN," etc. States of a temperature sensor may indicate whether the temperature sensor has been exposed to a temperature above or below a predetermined threshold (e.g., above 26 °C, below 0 °C, etc.), whether the temperature sensor is within a predetermined temperature range (e.g., -20 °C to 0 °C, 0-20 °C, 20-50 °C, etc.), or the actual temperature of the temperature sensor (e.g., as an integer number from 0 to 99 °C or °F). Thus, a consumer of a product, article or item to which the temperature sensor is attached can determine whether the product, article or item has been exposed to a temperature that might adversely affect the qualities of the product, article or item. The states of a humidity sensor may indicate whether the humidity sensor has been exposed to an environment having a relative humidity (which may be at a predetermined or reference temperature) within a predetermined range (e.g., 20-50%, 40-55%, etc.). The states of a timer may indicate whether a predetermined time period (e.g., 1 minute, 3 minutes, 1 hour, 8 hours, 7 days, etc.) has elapsed. It is within the abilities of one skilled in the pertinent art(s) to design and implement displays indicating such states of such sensors.

[0029] Furthermore, the display regions 30, 32 and 34 may independently comprise electrochromic displays, segment displays, liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, electroluminescent displays (ELDs), etc. In each display region 30, 32 and 34, the surface or cover of the display device 10 such be transparent or translucent. [0030] To maximize the shelf life of a display device 10 having printed and/or thin- film electrical circuitry or circuit elements therein, the display device 10 should be in a high ohmic OFF state when not in use. A high ohmic OFF state may be one in which the resistance of a conductive trace or line between the battery and the integrated circuit in the display device 10 approaches infinity (e.g., > 10 6 Ω, > 10 7 Ω, > 10 9 Ω, etc.). To ensure that the display device 10 is in a high ohmic OFF state, the pull tab 54 electrically isolates sections of conductive traces or lines between the battery and the integrated circuit that end in the area under the power-on button or region 20. Thus, the pull tab 54 generally comprises an electrically insulating material, such as a plastic sheet or film, although other insulating materials may be suitable. Upon removal (e.g., pulling) of the pull tab 54, the isolated sections of the conductive trace or line between the battery and the integrated circuit under the power-on button or region 20 contact each other and become electrically connected.

[0031] Pull tabs are commonly used to electrically isolate batteries from electrical circuitry (e.g., in toys, portable entertainment devices, etc.). However, such devices typically have a spring or other mechanism to secure the electrical connection between the battery and the electrical circuitry. In the display device 10, a spring or other force to secure the electrical connection may not be present. Therefore, in one embodiment, the pull tab 54 has an anisotropic conductive adhesive thereon that contacts each of the ends of the conductive traces or lines between the battery and the integrated circuit under the power-on button or region 20 upon removal of the pull tab 54. For example, the pull tab 54 is a liner (or an extension of a liner) of an anisotropic conductive tape.

[0032] Consequently, the power-on button or region 20 can function as a one-time

(programmable) switch that can remain permanently in the ON state. Such an OFF-to-ON type switch may comprise the pull tab 54 with a conductive adhesive on contact pads (e.g., on the underside of the surface or cover of the display device 10), such that when the user pulls the tab 54 and then presses on the power-on button or region 20, the battery is electrically connected to the integrated circuit, and the switch is permanently closed.

[0033] FIG. 2 shows an exemplary schematic 100 for the display device 10 of FIG. 1.

The device 10 comprises a printed integrated circuit (PIC) 110, a battery 120, discrete devices (e.g., capacitors) 122 and 124, a first sensor 130, a second sensor 140, a start button or switch 150, and displays 160, 162 and 164. The start button or switch 150 corresponds to the power-on button or region 20 in FIG. 1, and the displays 160, 162 and 164 correspond to the display regions 30, 32 and 34 in FIG. 1.

[0034] The PIC 110 generally includes a number of electrical circuit elements (e.g., transistors, resistors, capacitors, diodes, etc.) implemented in a plurality of layers that are formed by printing and (optionally) thin-film processing. The layers in the PIC 110 generally comprise at least one semiconductor (e.g., doped polysilicon) layer, a plurality of insulator layers (e.g., doped or undoped silicon dioxide, an electronics-compatible plastic, etc.), and one or more conductor layers (e.g., a metal such as aluminum, copper, silver, etc.). At least one layer in the PIC 110 is formed by printing (e.g., screen printing, inkjet printing, gravure printing, laser patterning, etc.). In one example, all of the layers in the PIC 110 are formed by printing. Printed integrated circuitry and methods of making the same are disclosed in U.S. Pat. Nos. 7,687,327 (IDR0502), 7,767,520 (IDR0742) and 8,796,125 (IDR0813) and U.S. Pat. Appl. No. 11/243,460 (IDR0272), the relevant portions of which are incorporated herein by reference.

[0035] The PIC 110 may further comprise a memory including one or more bits configured to store a value corresponding to the state of the first sensor, one or more bits configured to store a value corresponding to the state of each additional sensor, and a plurality of bits configured to store a unique identification code. The memory may further include bits of data corresponding to one or more predetermined thresholds (e.g., for use by a sensor or a comparator receiving a sensor output). The PIC 110 may thus further comprise one or more comparators configured to compare an output of a sensor with one or more predetermined thresholds, an optional driver (e.g., a pulse driver) configured to receive an output from the comparator and provide a storable sensor data signal to the memory, one or more sense amplifiers configured to convert data on one or more bit lines from the memory to digital signals, one or more optional latches configured to temporarily store the data from the sense amplifier(s), and one or more drivers or buffers (e.g., output buffers) configured to output the data (including identification code, when present) from the PIC 110. The PIC 110 may also contain a clock generator configured to provide a timing signal that controls the timing of certain operations in the PIC and a memory timing control circuit that controls the timing of memory read and/or write operations.

[0036] The battery 120 supplies power to the PIC 110 and the sensors 130 and 140.

Power may be supplied to the displays 160, 162 and 164 through the PIC 110. In alternative embodiments, the battery 120 supplies power directly to the displays 160, 162 and 164. The battery 120 may comprise a printed and/or thin film-type battery, comprising a first current collector, a first electrode (e.g., a cathode or anode), an electrolyte, a second electrode (e.g., the other of the cathode and anode), and a second current collector in sequence. The components of the battery 120 may be arranged vertically (e.g., as layers) or horizontally (e.g., as adjacent structures forming, for example, an interdigitated or comb-type battery). The battery 120 may be configured to provide an initial voltage (e.g., of from 1 to 20 V, or any value or range of values therein, such as 3 V, 6 V, 9 V, etc.). The capacitor 122 decouples (e.g., reduces) high and low frequency electrical noise between the traces to/from the positive and ground rails connected to the battery 120. In one example, the battery 120 may be centrally located in the display device 100 (e.g., so that none of the traces or wires from the battery 120 to other components in the display device 100 cross over another trace or wire). In an alternative embodiment, the display device 10 includes a wireless interface (e.g., an antenna, rectifier, modulator/demodulator, etc.) such as a near field communication (NFC), high frequency (HF) or radio frequency (RF) interface, in addition to or in place of the battery 120.

[0037] The sensor 130 may comprise a time sensor (see, e.g., U.S. Pat. Appl. No.

14/870,561, filed September 30, 2015, the relevant portions of which are incorporated herein by reference). The time sensor 130 comprises first and second resistors 132 and 134 in series. The first resistor 132 receives a power or voltage (e.g., VDD) from the PIC 110, and outputs from the first and second resistors 132 and 134 are respectively received at the terminals RST_ and VSNS_ on the PIC 110. In one example, the power or voltage from the PIC 110 at terminal VDDINT_ is the power or voltage provided from the battery 120. Alternatively, the power or voltage from the PIC 110 at terminal VDDINT_ is a divided or reduced voltage from the battery 120 (e.g., obtained by passing the battery voltage through a voltage divider or one or more diodes). The resistances of the first and second resistors 132 and 134 are generally different (e.g., the ratio of the resistances of the first resistor 132 to the second resistor 134 may be from 1 : 10 to 10:1, or any value or range of values therein), but in some embodiments they may be the same. In further embodiments, one or both of the first and second resistors 132 and 134 may be replaced with a programmable resistor network (e.g., a plurality of selectable parallel resistors, in which the total resistance is determined by selectively connecting or disconnecting various ones of the resistors in the network). The PIC 110 monitors the decay in the voltages at the RST_ and VSNS_ terminals, and when either or both of the voltages decreases to a predetermined value, the PIC 110 determines that a predetermined period of time has elapsed. Alternatively, the sensor 130 may comprise a chemical or humidity sensor (in which case the capacitor 124 and trace or wire to the RST_ terminal on the PIC 110 may not be present). Thus, the PIC 110 may comprise one or more comparators, each receiving an input from a corresponding and/or unique sensor terminal and another input corresponding to a threshold value for comparison with the input from the sensor terminal.

[0038] The second sensor 140 may comprise a temperature sensor. The temperature sensor 140 comprises first, second and third resistors or thermistors 142, 144 and 146 in series. For example, the temperature sensor 140 comprises a first thermistor 142 and first and second thermistors or bias resistors 144 and 146. The first resistor or thermistor 142 receives a power or voltage (e.g., VDD) from the PIC 110, and outputs from the first and second resistors or thermistors 142 and 144 are respectively received at the terminals VSNS_LO and VSNS_HI on the PIC 110. In one example, similar to the first sensor 130, the power or voltage from the PIC 110 at terminal VDDINT is the power or voltage provided from the battery 120, or a divided or reduced voltage thereof. The resistance of the first resistor or thermistor 142 generally differs from the resistances of the second and third resistors or thermistors 142 and 144, but the resistances of the second and third resistors or thermistors 142 and 144 may be the same or different, depending on the values of the temperature thresholds being sensed. The PIC 110 monitors voltages at the VSNS_LO and VSNS_HI terminals, and when the voltage at the VSNS_LO terminal exceeds a first threshold corresponding to a first temperature or the voltage at the VSNS_HI terminal decreases below a second threshold corresponding to a second temperature (the second temperature being less than the first temperature), the PIC 110 determines that a temperature excursion has occurred and changes the state of a respective signal on the HI or LO terminal to the respective display 162 or 164.

[0039] Alternatively, the second sensor 140 may comprise one or more chemical sensors configured to determine the presence or absence of one or more chemicals in the environment in which the display device 10 is placed, one or more continuity sensors configured to determine a continuity and/or security state of a package or container to which the device 300 is attached, one or more humidity sensors configured to determine a humidity level of the environment in which a package or container on which the display device 10 is attached or in which the display device 10 is placed, etc. Consequently, the integrated circuit 110 may comprise one or more comparators, each receiving one input from a corresponding sensor and another input corresponding to a threshold value for comparison with the input from the sensor. The threshold value(s) may be stored in a memory in the integrated circuit 110.

[0040] The displays 160, 162 and 164 may be or comprise a single- or multi-color electrochromic or LED (e.g., organic LED) display receiving one or more single- or multi-bit data and/or control signals from the integrated circuit 110. In the example of FIG. 2, the display 160 receives a single-bit signal from the terminal ON and displays an indicator indicating that the display device is operational when the wire segments or traces between the battery 120 and the integrated circuit 110 are electrically connected, the display 162 receives a single-bit signal from the terminal HI and displays (i) a first temperature indicator when the display device 10 has been exposed to a temperature greater than a first temperature and (ii) a second temperature indicator when the display device 10 has not been exposed to a temperature greater than the first temperature, and the display 164 receives a single-bit signal from the terminal LO and displays (i) a third temperature indicator when the display device 10 has been exposed to a temperature less than a second temperature and (ii) a fourth temperature indicator when the display device 10 has not been exposed to a temperature less than the second temperature. Typically, the second temperature is less than the first temperature.

[0041] Furthermore, when the display device 10 has a time sensor 130 in addition to a temperature (or other) sensor 140, the integrated circuit 110 may be configured to monitor the temperature using the temperature sensor 140 and validate a temperature excursion (e.g., above or below a predetermined threshold temperature) after a specified delay time. To ensure that a temperature excursion is valid, the temperature excursion should be more than momentary (e.g., it should last for at least a predetermined length or period of time). This validation function is implemented by the time sensor 130 and the PIC 110. The time sensor 130 starts when the temperature excursion occurs (e.g., by the PIC 110 activating the signal at the VDDINT_ terminal) and resets if the temperature crosses the threshold temperature in the opposite direction within the predetermined length or period of time (e.g., Tdeiay, which may be for example from 1 second to 1 week, 1 minute to 4 hours, or any value or other range of values therein, and which may be programmable or user-selectable). If, instead, the temperature stays in the excursion temperature range until after the expiration of Tdeiay, the PIC 110 may record and/or indicate that the temperature excursion is a valid excursion by turning on the corresponding display 162 or 164 (e.g., with an "X" when text or other graphics in the adjacent graphics region indicates what the temperature excursion is, such as "Above 28 °C")- Consequently, the present PIC 110 and sensors 130 and 140 may be configured to validate the state of the sensors before displaying an indicator corresponding to the state on the corresponding display 162 or 164. Alternatively, the displays 162 and 164 may be configured to display one indicator for a sensor state that has not been validated, and a different indicator for the sensor state after being validated.

[0042] However, the display device 10 is not limited to such configurations. For example, in a display device including a single temperature sensor, only one of the displays 162 and 164 and one of the traces from corresponding the HI and LO terminals are present. Also, the display 162 may display only the first temperature indicator when the display device 10 has been exposed to a temperature greater than the first temperature (i.e., when the display device 10 has not been exposed to a temperature greater than the first temperature, the display 162 may remain blank or display nothing), and the display 164 may display only the third temperature indicator when the display device 10 has been exposed to a temperature less than the second temperature (i.e., when the display device 10 has not been exposed to a temperature less than the second temperature, the display 164 may remain blank or display nothing). Additionally, the display 162 may display the first temperature indicator when the display device 10 has been exposed to a temperature less than the first temperature, and/or the display 164 may display the third temperature indicator when the display device 10 has been exposed to a temperature greater than the second temperature. Variations of the display indicators and the thresholds and/or comparisons defining different sensor states are practically limitless.

An Exemplary Method of Making a Printed Electronic Display Device

[0043] The present invention also concerns a method of making a printed electronic display device. FIGS. 3A-H are cross-sectional and plan views of structures for explaining an exemplary method of manufacturing a printed electronic display device including one or more displays, one or more sensors, and a pull tab-type OFF-to-ON switch. FIG. 3A shows a substrate 200 on which the printed electronic display device is formed. The substrate 200 may have a standard or non-standard size and/or shape. The substrate can be flexible (e.g., a flexible plastic film, a metal foil, etc.), rigid (e.g., a film or sheet of an epoxy, an acrylate or methacrylate, a polycarbonate, a resin-impregnated glass or cloth ["pre-preg"] conventionally used in printed circuit boards, etc.), or may comprise a flexible material secured to a rigid substrate (e.g., for placing and/or mounting components such as the display[s], sensor[s] and PIC on the flexible material using surface mount technology [SMT] processing). In embodiments in which components are secured to the substrate 200 at a temperature of 140°C or less, the substrate 200 can be or comprise polyethylene terephthalate (PET). Alternatively, the substrate 200 can be or comprise a polyimide.

[0044] FIG. 3B shows the substrate 200 with a printed integrated circuit (PIC) 210 and a battery 220 thereon. The PIC 210, which may be similar or identical to the PIC 110 in FIG. 2, may be formed directly on the substrate 200 (e.g., by printing, and optionally, by thin film processing a plurality of layers in predefined patterns to form electrical components and/or devices) or on a separate substrate that is then attached or secured to the substrate 200 (e.g., by SMT). The battery 220, which may be similar or identical to the battery 120 in FIG. 2, may be formed directly on the substrate 200 (e.g., by printing, and optionally, by thin film processing a plurality of materials in predefined patterns to form first and second current collectors, a cathode, and anode, and an electrolyte as described herein) or on a separate substrate that is then attached or secured to the substrate 200 (e.g., by SMT).

[0045] Traces or wires 230 and 232, electrically connected to the printed integrated circuit 210 and the battery 220, respectively, extend from the printed integrated circuit 210 and battery 220 toward each other. The traces or wires 230 and 232 may comprise a metal (e.g., aluminum, copper, silver, etc.), an alloy (e.g., an aluminum-copper alloy, a titanium- copper alloy, a nickel-copper alloy, etc.), or a conductive compound (e.g., indium tin oxide, graphene, titanium nitride, etc.). The traces or wires 230 and 232 may be printed on the substrate, generally along with the traces or wires between the PIC 210 and the sensor(s) and display(s) (not shown), as well as between the battery 220 and the sensor(s) and/or any discrete components. As shown in FIG. 3C, the traces or wires 230 and 232 may have an L- shape (e.g., in which the distal portion of the "L" points toward the nearest peripheral edge of the substrate 200).

[0046] FIG. 3D shows an overlay 260 with a spacer 250 secured thereto or laminated therewith (e.g., with a thin layer of adhesive [not shown] therebetween). A tape or liner 242 with a conductive adhesive 240 thereon is adhered to the spacer in a location corresponding to the portions of the L-shaped traces or wires 230 and 232 (FIG. 3C) extending toward the peripheral edge of the substrate 200. The tape or liner 242 typically comprises a flexible plastic film with low adhesion (e.g., polyethylene, polypropylene, polyvinyl chloride, a polyfluoroethylene, a polyester such as PET, a copolymer and/or blend thereof, etc., any of which can be coated with a release agent such as a silicone). In various embodiments, the conductive adhesive 240 comprises a conventional anisotropic conductive adhesive.

[0047] The spacer 250 has a cutout region, trench or opening 255 corresponding to the region(s) or area(s) on the substrate 200 containing the PIC 210 and the battery 220. The spacer 250 generally has its maximum thickness at the periphery of the overlay 260, and substantially less than its maximum thickness (e.g., 0-80%, or any value or range of values therein) in the cutout region, trench or opening 255. The cutout region, trench or opening 255 is also in areas corresponding to the region(s) or area(s) on the substrate 200 containing discrete component(s). The spacer 250 is generally completely absent in areas corresponding to the region(s) or area(s) on the substrate 200 containing the display(s). For clarity, the cutout region, trench or opening 255 is shown in areas corresponding to the region(s) or area(s) on the substrate 200 containing the traces or wires 230 and 232, although in practice, the spacer 250 may have its maximum or substantially maximum thickness in areas corresponding to the region(s) or area(s) on the substrate 200 containing only traces or wires.

[0048] The overlay 260 generally protects the outer surface of the display device. In various embodiments, the overlay 260 further includes graphics, such as artwork, symbols, icons, text, background coloring, etc., thereon. For example, the graphics can include text and/or symbols indicating the location of the OFF-to-ON switch, the information that is displayed on the display (s), such as whether the display device has been exposed to a temperature above or below a threshold temperature (and optionally for at least a predetermined length of time), a humidity above or below one or more threshold humidity levels, an environment containing at least a threshold concentration of a particular chemical compound or type of chemical compound, etc. In one example, the graphics are printed on the underside of the overlay 260. Alternatively, the graphics are printed on the outer surface of the overlay 260.

[0049] FIG. 3E shows a plan or top view of the spacer 250 with the conductive adhesive 240 and the tape or liner 242 thereon. The tape or liner 242 is over the conductive adhesive 240, and the conductive adhesive 240 is shown through the tape or liner 242. The tape or liner 242 further includes a pull tab portion 244 that extends beyond the peripheral edge of the spacer 250 (and thus, of the display device). In one embodiment, the liner or tape 242 is folded in a way such that pull tab portion 244 extends beyond the peripheral edge of the spacer 250 and of the substrate 200. The tape or liner 242 and pull tab 244 may be produced in a conventional label making machine. Alternatively, the tape or liner 242 and pull tab 244 with the conductive adhesive 240 thereon can be obtained from a commercial supplier in a predefined or predetermined configuration.

[0050] FIG. 3F shows the overlay 260, spacer 250, conductive adhesive 240 and tape or liner 242 on the substrate 200, PIC 210, battery 220 and traces 230 and 232. The spacer 250 is attached or secured to the substrate 200 using a conventional nonconductive adhesive. Generally, the spacer 250 is attached or secured to the substrate 200 in regions where the spacer 250 has is maximum or substantially maximum thickness. The tape or liner 240 is between the conductive adhesive 242 and the traces or wires 230 and 232.

[0051] FIG. 3G shows a plan or top-down view of the device of FIG. 3F with the overlay 260 and the spacer 250 removed for clarity. The conductive adhesive 242 overlaps the traces or wires 230 and 232. As a result, when the user pulls the tab 244 and removes the liner or tape 242, the conductive tape 240 is fully exposed to the traces or wires 230 and 232. A force is applied to the overlay (e.g., label) 260 as shown by the arrows in FIG. 3H to form a stable electrical connection between the traces or wires 230 and 232. In one example, the force is applied by the user pressing a thumb, finger or other instrument on a predetermined and/or indicated location (e.g., the "START" button 20 in FIG. 1).

An Exemplary Printed Electronic Device with a Reliable Power-on Switch Having a High Ohmic OFF State

[0052] FIG. 4 shows another exemplary display device 300 that is substantially the same as the display device 10 of FIG. 1, except that the OFF-to-ON switch 320 comprises a bi-stable metal dome switch. Metal dome switches are usually momentary (i.e., they remain in the depressed position only as long as a force is applied to them), but bi-stable variants are known. Metal dome switches can have a low profile (e.g., a relatively small height). For example, as shown in FIG. 5, a metal dome switch 322 can have a height H of from 0.15 to

0.5 mm, but are not limited thereto. Also, in a plan view, metal dome switches may have a circular shape (FIG. 6A), a notched or truncated circular shape (FIG. 6B), or a four-legged shape (FIG. 6C). The metal dome switches may be dimpled, such as domes 324 and 326 (FIGS. 6A-B), or undimpled, such as domes 322 and 328 (FIGS. 5 and 6C). The metal dome switches 322-328 may have a width or diameter of from 2.5 to 10 mm, but are not limited thereto. Such bi-stable metal dome switches are available commercially from Nicomatic International (Bons-en-Chablais, France) and Snaptron, Inc. (Windsor, Colorado, USA).

[0053] FIG. 7 shows an alternative layout of the structure shown in FIG. 3, in which the trace 330 from the PIC 210 and the trace 332 from the battery 220 are electrically disconnected. A metal dome switch (e.g., dome switch 334, 336 or 338) may be mounted or secured to the U-shaped end of the trace 330 using, for example, a conductive adhesive or solder (e.g., a low-melting point solder). When the metal switches 326 and 328 (FIGS. 6B- C) are used, a notch or truncation 327 or a gap 329 between legs is placed over the portion 335 of the trace 332. When the metal switch 324 (FIG. 6A) is used, a thin electrically- insulative layer may be formed over the portion 335 of the trace 332. Alternatively, an insulative coating may be formed on a portion of the metal switch 324 that is placed over the portion 335 of the trace 332.

[0054] However, the "switch-back" force in some bi-stable metal dome switches may be too small to give a stable ON connect in flexible embodiments of the present display device. Therefore, in such embodiments, the OFF-to-ON switch 320 (FIG. 4) may further comprise a conductive adhesive. In one embodiment, the conductive adhesive is placed on the underside of the metal dome in a location that will come in contact with the trace 332 when the metal dome is depressed. Alternatively, the conductive adhesive may be placed on the end of the trace 332 inside the U shape of trace 330 (e.g., between portion 335 and the PIC 210). In one example, the conductive adhesive comprises an anisotropic conductive tape (e.g., with any liner that may have been in contact with the conductive adhesive removed). When the metal dome is pressed, an electrical connection is made between the traces 330 and 332, and the connection is initially held by the stable depressed state of the dome. The anisotropic conductive tape increases the force needed to switch the stable depressed metal dome back to its other stable (i.e., non-depressed) state, and thereby provides a more stable ON switch. In embodiments of the flexible display device, the conductive adhesive increases the force needed to change the dome back to its non-depressed state when the display device is bent (e.g., in the same direction[s] in which the metal dome switch is bent).

[0055] The bi-stable metal dome is commercially available from Nicomatic

International. The conductive adhesive may be made in tape form in a conventional label maker or purchased in a predefined or predetermined configuration from any of a number of commercial suppliers. Alternatively, the conductive adhesive may be formulated into an ink or solution and printed onto the metal dome or the trace or wire 332 by conventional processes.

[0056] FIG. 8 shows a cross-sectional view of a prototype display device 400, taken along the X-X' line in FIG. 4. The display device 400 includes a substrate 410, a metal wiring or trace layer 420, a printed integrated circuit 430, a display 440, a spacer 450, and a graphical and/or protective overlay 460. The display device 400 may further comprise a battery, an OFF/ON switch and one or more discrete electrical components (such as a capacitor, resistor, diode, etc.).

[0057] The substrate 410 comprises a thin sheet of rigid or flexible insulative material as described herein. In one example, the substrate 410 comprises a PET film or sheet with a graphical and/or protective underlay thereunder. The PET film or sheet and the graphical and/or protective underlay may be secured to each other, e.g., with a thin layer of adhesive (not shown). The metal wiring or trace layer 420 is shown as a representation of the wires or traces printed or otherwise formed on the substrate 410. In practice, the metal wiring or trace layer 420 comprises a plurality of metal traces electrically isolated from each other, but which electrically connect different components in the display device 400 to each other.

[0058] The printed integrated circuit 430 is the same as or similar to the PICs described herein (e.g., PICs 110 and 210 in FIGS. 2, 3B-C and 3F-H), and the display 440 is the same as or similar to the displays described herein (e.g., displays 30-34 and 160-164 in FIGS. 1-2 and 4). The spacer 450 is the same as or similar to the spacers described herein (e.g., spacer 250 in FIGS. 3D-F and 3H). The graphical and/or protective overlay 460 is the same as or similar to the overlay 260 in FIGS. 3D-F and 3H, but a transparent or translucent portion 465 having no graphics therein is shown over the display 440.

[0059] The display device 400 further includes a plurality of test holes or openings

470, 472 and 474 configured to enable testing of the display device 400 prior to shipment to a customer or distributor. After testing, the test holes or openings 470, 472 and 474 can be covered or sealed with adhesive tape or a label with an adhesive backing and optional graphics thereon.

Exemplary Methods of Using Electronic Display Devices

[0060] The present invention also concerns a method of operating an electronic display device, where the electronic display device includes one or more displays, a printed integrated circuit, a battery, and an OFF-to-ON switch having a high ohmic OFF state. The method comprises electrically connecting first and second ends of first and second traces on a substrate using such a switch, and displaying information on at least one of the displays receiving at least one output from the printed integrated circuit. The ends of the traces are in proximity to each other. The printed integrated circuit is electrically connected to the first trace, and the battery is electrically connected to the second trace. The ON state of the switch electrically connects the ends of the first and second traces, and the OFF state of the switch imparts a high ohmic resistance between the ends of the first and second traces.

[0061] In some embodiments, the switch comprises a conductive adhesive and a pull tab connected to an insulating liner or tape. The insulating liner or tape is between the conductive adhesive and the ends of the first and second traces. In such embodiments, the switch is placed in the ON state by removing the pull tab and compressing the conductive adhesive towards the ends of the first and second traces.

[0062] In some alternative embodiments, the switch comprises a metal dome electrically connected to one of the first and second ends of the first and second traces. Such metal domes may be mechanically stable in each of the ON and OFF states. In embodiments including a flexible substrate or a metal dome that may not be as stable as desired when in the ON state, the metal dome may further comprise a conductive adhesive on underside (and optionally covering the center) of the dome. Generally, compression of the metal dome causes the metal dome to electrically contact the other end of the trace to which it is not electrically connected. In both cases (i.e., where the switch comprises [i] a conductive adhesive and a pull tab or [ii] a metal dome), the conductive adhesive may an anisotropic conductive adhesive (e.g., an anisotropic conductive tape).

[0063] In embodiments in which electronic display device includes one or more sensors electrically connected to the printed integrated circuit, the method may further comprise determining a state of the sensor(s). As discussed herein, at least one of the one or more sensors may also be electrically connected to the battery. Further embodiments may comprise determining the state of a plurality of sensors, each of which is electrically connected to the printed integrated circuit. As described herein, the sensor(s) may be selected from chemical sensors, continuity sensors, temperature sensors, humidity sensors and timers. [0064] Certain embodiments of the method of operating may comprise displaying information on each of a plurality of displays, each of which is electrically connected to the printed integrated circuit. In embodiments including one or more sensors, the display(s) may be configured to indicate a state of a corresponding sensor or sensors. As described herein, the display (s) may be selected from electrochromic displays, segment displays, liquid crystal displays (LCDs), light emitting diode (LED) displays, organic LED (OLED) displays, and electroluminescent displays (ELDs).

[0065] As discussed herein, the method of operating is particularly advantageous when the display device includes a printed integrated circuit. The printed integrated circuit generally comprises a plurality of layers, and one or more layers of the printed integrated circuit may comprise a printed conductor, semiconductor or insulator. In some embodiments, all or substantially all of the layers of the printed integrated circuit comprise a printed material.

[0066] Furthermore, the battery may comprise a plurality of layers, and one or more layers of the battery may comprise a printed material. In some embodiments, a plurality of layers of the battery comprise a printed layer.

[0067] As mentioned herein, the substrate may be flexible, but is not so limited. For example, the substrate may comprise a plastic sheet or film, paper, a metal foil or film, or a combination thereof. In general, the substrate has an electrically insulating surface, and in some cases, the substrate comprises a flexible material with a protective and/or graphical underlay in contact therewith. In one example, the substrate comprises polyethylene terephthalate (PET).

[0068] In some embodiments, the electronic display device further comprises a graphical and/or protective overlay on an outermost surface. In general, the portion(s) of the graphical and/or protective overlay over the display(s) is/are transparent or translucent. In addition, the electronic display device may further comprise a spacer between the substrate and the graphical and/or protective overlay. The spacer generally includes a cutout, trench or opening in locations corresponding to each of the display(s), the printed integrated circuit, the battery and the switch.

CONCLUSION

[0069] The present invention advantageously improves the shelf life of electronic display devices including a printed integrated circuit, a battery (which may also be printed), and a display, particularly on a flexible substrate (such as PET or other labeling material). The improved shelf life also improves performance of the battery, and thus, of the printed integrated circuit, display(s) and any sensor(s) in the device. The present invention can be implemented using conventional and/or relatively simple, low-cost, and widely available equipment and materials.

[0070] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.