Selective metal removal process for metallized retro-reflective and holographic films and radio frequency devices made therewith

• US 20020160786A1
• Filed: 04/09/2002
• Published: 10/31/2002
• Est. Priority Date: 04/30/2001
• Status: Active Grant

• Current Assignee: Neology Incorporated (OEP Technologie BV)
• Original Assignee: Neology Incorporated (OEP Technologie BV)
• Inventors: Martinez de Velasco Cortina, Francisco, Rietzler, Manfred
• Granted Patent: US 7,034,688 B2
• Time in Patent Office: Days
• US Class Current: 455/455
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• 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
• CPC Class Codes: G06K 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag
• CPC Class Codes: G06K 19/0776 the adhering arrangement being a layer of adhesive, so that the record carrier can function as a sticker
• CPC Class Codes: G06K 19/07771 the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/16 the marking being a hologram or diffraction grating
• CPC Class Codes: G06K 19/18 Constructional details
• CPC Class Codes: G06K 2019/0629 Holographic, diffractive or retroreflective recording
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 9/27 Spiral antennas
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer elastomeric conductor H05K2201/0314
• CPC Class Codes: H05K 2203/0143 : Using a roller; Specific shape thereof; Providing locally adhesive portions thereon
• CPC Class Codes: H05K 2203/1545 : Continuous processing, i.e. involving rolls moving a band-like or solid carrier along a continuous production path
• CPC Class Codes: H05K 3/067 : Etchants
• CPC Class Codes: H05K 3/068 : Apparatus for etching printed circuits
• CPC Class Codes: Y10T 29/49016 : Antenna or wave energy "plumbing" making

Abstract

A method for selectively removing metal from a metallized substrate (e.g., a metallized polymer film) and the formation fo devices thereby are provided. The method involves selectively exposing the metallized surface to a demetallizing (i.e., an oxidizing) chemical solution. The metallized layer can be selectively exposed to the demetallizing solution using a flexographic printing process wherein printing rollers are used to transfer the demetallizing solution to the metallized surface. An identification device including, for example, a holographic, retro-reflective, or other metallized material and a radio-frequency transponder are also provided. The radio-frequency transponder includes an RF chip and an antenna in electrical communication with the chip. The identification device including the holographic image allows both electronic identification through the reading of identification data stored in the chip and optical identification via the holographic image.

Claims

1. An identification device, comprising:

a base layer;

a radio-frequency (RF) transponder comprising an RF chip and an antenna disposed on the base layer, wherein the antenna is in electrical communication with the chip; and

a metallized region;

wherein the metallized region has been selectively demetallized, such that the RF transponder is able to transmit and receive information.

2. The device of claim 1, wherein the metallized region includes an image.

3. The device of claim 2, wherein the image is a holographic image.

4. The device of claim 1, wherein the metallized region includes a retro-reflective layer.

5. The device of claim 1, wherein the metallized region comprises a holographic image and wherein the holographic image and the antenna form a single metal layer.

6. The device of claim 1, wherein the base layer has at least one side, and wherein the antenna and the metallized region are located on the same side of the base layer.

7. The device of claim 1, wherein the base layer has at least a first side and a second side, the first side being opposite the second side, and wherein the antenna and the metallized region are located on opposite sides of the base layer.

8. The device of claim 1, wherein the base layer has at least a first side and a second side, the first side being opposite the second side, and wherein a first part of the antenna and the metallized region are located on the first side, and a second part of the antenna is located on the second side of the base layer, and wherein the first part of the antenna is electrically connected to the second part of the antenna.

9. The device of claim 1, wherein the device comprises an upper metal layer positioned above the base layer and a lower metal layer positioned below the base layer, wherein a first part of the antenna is formed on the upper metal layer and a second part of the antenna is formed on the lower metal layer, the device further comprising a through contact connecting the first part of the antenna to the second part of the antenna.

10. The device of claim 1, wherein the metallized region is in electrical communication with the antenna.

11. The device of claim 10, wherein the metallized region comprises an electronic commutation element.

12. The device of claim 10, wherein the metallized region comprises a capacitor.

13. The device of claim 1, wherein the metallized region comprises a plurality of electrically isolated holographic regions.

14. The device of claim 1, wherein the base layer is an electrically conductive layer.

15. The device of claim 14, wherein an isolation layer is formed on the base layer.

16. The device of claim 15, wherein the radio frequency (RF) chip is mounted on the isolation layer.

17. The device of claim 15, wherein the base layer includes a depressed region, and wherein the isolation layer is formed in the depressed region.

18. The device of claim 1, wherein the base layer has at least one side, and wherein the antenna and the metallized region are formed on the same side of the base layer in discrete, non-overlapping areas.

19. The device of claim 1, wherein the antenna comprises a conductive wire inlaid in a polymer layer.

20. The device of claim 1, wherein the device is selected from the group consisting of a decal, a license plate, and an identification card.

21. The device of claim 1, wherein the metallized region has been selectively demetallized in a square grid pattern.

22. The device of claim 21, wherein the squares in the square grid pattern have a length of about 5 mm or less.

23. The device of claim 21, wherein the squares in the square grid pattern have a length of about 3 mm or less.

25. The method of claim 24, wherein the printing process is selected from the group consisting of a flexographic printing process, an offset printing process and a screen printing process.

26. The method of claim 24, wherein the metal etching solution is an aqueous solution of sodium hydroxide.

27. The method of claim 26, wherein the metal etching solution further comprises ethylene glycol.

29. The method of claim 28, wherein the first and second metallized regions form a single metal layer.

24. A method of forming a pattern in a metallized region, the method comprising:

transferring a metal etching solution to portions of an exposed surface of the metallized region using a printing process;

allowing the etching solution to react with the metallized region to selectively demetallize the surface; and

washing the selectively demetallized surface.

28. A method of making an identification device comprising a base layer and a plurality of metallized regions disposed thereon, the method comprising:

forming an antenna in a first metallized region; and

forming a holographic image in a second metallized region;

wherein the antenna is formed by a method comprising;

transferring a metal etching solution to portions of an exposed surface of the metallized layer using a printing process;

allowing the etching solution to react with the metal to selectively demetallize the surface; and

washing the selectively demetallized surface.

30. A method of making an identification device comprising a base layer and at least one metal region disposed thereon, the method comprising:

selectively demetallizing a first metal region of the device;

forming a holographic image in the first metal region;

forming an antenna on the base layer; and

mounting an radio frequency (RF) chip on the base layer in electrical communication with the antenna to form an RF transponder;

wherein the selective demetallization of the first metal region allows the RF transponder to transmit and receive information.

31. The method of claim 30, wherein selective demetallization comprises:

transferring a metal etching solution to portions of an exposed surface of the first metal region using a printing process;

allowing the etching solution to react with the metal; and

washing the exposed surface of the first metal region.

32. The method of claim 30, wherein forming an antenna comprises:

forming an inlaid antenna by embedding a conductive wire in a polymer layer; and

affixing the inlaid antenna to the device.

33. The method of claim 32, wherein the inlaid antenna is provided with an adhesive layer and wherein affixing the inlaid antenna to the device comprises:

adhesively bonding the antenna to the device.

34. The method of claim 33, wherein the adhesive is selected from a group consisting of an auto-adhesive and a pressure sensitive adhesive.

36. The method of claim 35, wherein the base layer has at least one side, and wherein the antenna and the retro-reflective layer are formed on the same side of the base layer in discrete, non-overlapping regions.

37. The method of claim 35, wherein forming an antenna comprises:

forming an inlaid antenna by embedding a conductive wire in a polymer layer; and

affixing the inlaid antenna to the base layer.

38. The method of claim 37, wherein the inlaid antenna is affixed to a demetallized region of the retro-reflective layer

39. The method of claim 37, wherein the inlaid antenna is provided with an adhesive layer and wherein affixing an antenna further comprises:

adhesively bonding the antenna to the device through the adhesive layer.

40. The method of claim 38, wherein the adhesive is selected from a group consisting of an auto-adhesive and a pressure sensitive adhesive.

41. The method of claim 37, wherein the polymer layer comprises polyvinyl chloride (PVC) or polyethylene terephthalate (PET).

42. The method of claim 36, wherein the radio frequency (RF) chip is mounted on the same side of the base layer as the antenna and retro-reflective layer.

43. The method of claim 35, further comprising:

forming a depressed region in the base layer; and

forming an isolation layer in the depressed region;

wherein the radio frequency (RF) chip is mounted on the isolation layer.

44. The method of claim 43, wherein the antenna is formed on top of the depressed region.

45. The method of claim 43, wherein the isolation layer comprises a ferrite composite.

46. The method of claim 35, further comprising:

over-printing a design on the surface of the retro-reflective material.

47. The method of claim 35, wherein selectively demetallizating comprises:

transferring a metal etching solution to portions of an exposed surface of the metallized retro-reflective layer using a printing process;

allowing the etching solution to react with the metal; and

washing the exposed surface of the metallized retro-reflective layer.

48. The method of claim 47, wherein the metal etching solution is transferred to the exposed surface of the metallized retro-reflective layer as a plurality of lines arranged in a square pattern.

49. The method of claim 48, wherein the lines are spaced apart about 5 mm or less.

50. The method of claim 48, wherein the lines are spaced apart about 3 mm or less.

51. The method of claim 35, wherein the base layer comprises a polymeric material and wherein forming an antenna comprises:

forming an inlaid antenna by embedding a conductive wire in the base layer.

52. The method of claim 51, wherein a demetallized portion of the retroreflective layer is applied over the antenna layer.

35. A method of making an identification device comprising a base layer and a metallized retro-reflective layer, the method comprising:

forming a selectively demetallized retro-reflective layer.on the base layer;

forming an antenna on the base layer; and

mounting a radio frequency (RF) chip on the base layer;

wherein the chip the and the antenna are in electrical communication to form an RF transponder and wherein the selective demetallization of the retro-reflective layer retains the retro-reflective properties of the retro-reflective layer while allowing the RF transponder to transmit and receive information.