Radio frequency identification tag and method of making the same

• US 7,221,277 B2
• Filed: 10/05/2004
• Issued: 05/22/2007
• Est. Priority Date: 10/05/2004
• Status: Expired

• Current Assignee: Michael Caron Incorporated
• Original Assignee: Tracking Technologies Incorporated
• Inventors: Nablo, Samuel V., Frazier, John Paul, Caron, Michael Roger
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): Mehmood; Jennifer
• Application Number:
  US10/958,699
• Publication Number:
  US 20060071792A1
• Time in Patent Office: 959 Days
• Field of Search: 3405681-5688, 340/571, 3405721-5729, 235/482, 235/492, 295/921, 296/00, 296/01, 295/92
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/0775 arrangements for connecting the integrated circuit to the antenna

Abstract

The present invention describes a process for manufacture of RFID tags. The RFID tag of the present invention includes a substrate, an antenna, and a die positioning structure disposed on the substrate that is cast and cured specifically for receiving a silicon die of the type typically used in RFID applications. The substrate is selected from a number of materials, the properties of which render it penetrable by electron beam radiation. The die positioning structure is a second material which is electron beam curable, and which is deposited and cured at high speed on the substrate in a novel fashion in accordance with the present invention in a highly efficient, reproducible and economical manner.

Claims

1. A radio frequency identification (RFID) tag comprising:

a substrate material;

an antenna disposed on the substrate;

a die positioning structure disposed on the substrate and defining a cavity for receiving a silicon die; and

a silicon die disposed in the die positioning structure, and in contact with the die positioning structure, the silicon die having at least one bond for connecting to the antenna.

2. The RFID tag of claim 1 wherein the die positioning structure defines a cavity, and further wherein the cavity defines a first surface adjacent to the substrate and a second surface, the second surface disposed at an angle relative to the first surface, the angle being between 100 and 110 degrees.

3. The RFID tag of claim 1 wherein the antenna is selected from the group consisting of gold, copper, silver, aluminum, zinc or tungsten.

4. The RFID tag of claim 1 wherein the antenna is gold.

5. The RFID tag of claim 1 wherein the antenna is copper.

6. The RFID tag of claim 1 wherein the antenna is silver.

7. The RFID tag of claim 1 wherein the antenna is aluminum.

8. The RFID tag of claim 1 wherein the substrate is selected from the group consisting of polyimide, polyester, polyethylene, polypropylene, cotton-polyester blend, extrusion coated paper, impregnated paper, or thermal label.

9. The RFID tag of claim 1 wherein the substrate comprises polyimide.

10. The RFID tag of claim 1 wherein the substrate comprises polyester.

11. The RFID tag of claim 1 wherein the substrate comprises polyethylene.

12. The RFID tag of claim 1 wherein the substrate comprises polypropylene.

13. The RFID tag of claim 1 wherein the substrate comprises of one of cotton-polyester blend.

14. The RFID tag of claim 1 wherein the substrate comprises extrusion coated paper.

15. The RFID tag of claim 1 wherein the substrate comprises impregnated paper.

16. The RFID tag of claim 1 wherein the substrate comprises thermal label.

17. The RFID tag of claim 1 wherein the substrate is between 0.0025 and 0.0125 cm in thickness.

18. The RFID tag of claim 1 wherein the substrate is between 0.005 and 0.01 cm in thickness.

19. The RFID tag of claim 1 wherein the substrate is between 0.006 and 0.008 cm in thickness.

20. The RFID tag of claim 1 wherein the silicon die is one of a read-only memory chip, an electrically programmable read-only memory chip, or an electrically erasable programmable read-only memory chip.

21. The RFID tag of claim 1 wherein the antenna is operable between 915 and 920 Megahertz.

22. The RFID tag of claim 1 wherein the antenna is operable between 868 and 869 Megahertz.

23. The RFID tag of claim 1 wherein the antenna is operable between 100 and 150 kilohertz.

24. The RFID tag of claim 1 wherein the antenna is operable between 950 and 960 Megahertz.

25. The RFID tag of claim 1 wherein the antenna is operable between 2.4 and 2.5 Gigahertz.

30. The method of claim 25 wherein the substrate is selected from the group consisting of polyimide, polyester, polyethylene, polypropylene, cotton-polyester blend, extrusion coated paper, impregnated paper, or thermal label.

31. The method of claim 25 wherein the substrate comprises polyimide.

32. The method of claim 25 wherein the substrate comprises polyester.

33. The method of claim 25 wherein the substrate comprises polyethylene.

34. The method of claim 25 wherein the substrate comprises polypropylene.

35. The method of claim 25 wherein the substrate comprises cotton-polyester blend.

36. The method of claim 25 wherein the substrate comprises extrusion coated paper.

37. The method of claim 25 wherein the substrate comprises impregnated paper.

26. A method of manufacture for a radio frequency identification (RFID) tag, the method comprising:

providing a substrate;

providing an antenna preformed on the substrate;

providing a second material;

providing a negative cast of a die positioning structure;

pressing the second material between the substrate and the negative cast, thereby providing a die positioning structure;

curing the second material, thereby providing a cured die positioning structure; and

affixing a silicon die within the cured die positioning structure, such that the silicon die is in contact with the cured die positioning structure.

27. The method of claim 26 wherein the step of curing the second material comprises irradiating the second material with an electron beam.

28. The method of claim 26 wherein the step of curing the second material comprises irradiating the second material with an electron beam having an energy of between 100 and 300 kiloelectron volts.

29. The method of claim 26 wherein the step of curing the second material comprises irradiating the second material with an electron beam having an energy of 200 kiloelectron volts.

38. The method of claim 26 wherein the substrate comprises thermal label.

39. The method of claim 26 wherein the substrate is between 0.0025 and 0.0125 cm in thickness.

40. The method of claim 26 wherein the substrate is between 0.005 and 0.01 cm in thickness.

41. The method of claim 26 wherein the substrate is between 0.006 and 0.008 cm in thickness.

42. The method of claim 26 wherein the step of providing a negative cast of a die positioning structure comprises providing a platen.

43. The method of claim 42 wherein the platen is comprised of brass.

44. The method of claim 42 wherein the step of providing a negative cast of a die positioning structure comprises providing a platen disposed for repeated pressing of the negative cast of the die positioning structure.

45. The method of claim 42 wherein the platen is a cylinder disposed for continuous rolling.

46. The method of claim 26 further comprising the step of applying bonding adhesives to at least one antenna contact point, the antenna contact point disposed in the die positioning structure.

47. The method of claim 26 wherein the silicon die is one of a read-only memory chip, an electrically programmable read-only memory chip, or an electrically erasable programmable read-only memory chip.

48. The method of claim 26 wherein the silicon die is an electrically erasable programmable read-only memory chip.

49. The method of claim 26 further comprising the step of providing a non-conductive protective layer protecting the silicon die and the die positioning structure.

50. The method of claim 26 further comprising the step of irradiating the antenna with electromagnetic radiation to test the operability of the RFID tag.

51. The method of claim 26 further comprising the step of introducing ultraviolet radiation blocking pigments into the second material.