Laser ablating structures for antenna modules for dual interface smartcards

• US 9,272,370 B2
• Filed: 05/19/2014
• Issued: 03/01/2016
• Est. Priority Date: 08/12/2010
• Status: Active Grant

• Current Assignee: AmaTech Group Limited (Paragon Group Limited)
• Original Assignee: Féinics AmaTech Teoranta (Paragon Group Limited)
• Inventors: Finn, David, Lotya, Mustafa
• Primary Examiner(s): Haupt, Kristy A
• Application Number:
  US14/281,876
• Publication Number:
  US 20140284386A1
• Time in Patent Office: 652 Days
• US Class Current: 1/1
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/361 for deburring or mechanical trimming B23K26/351 takes precedence
• CPC Class Codes: B23K 26/362 Laser etching
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: G06K 19/0775 arrangements for connecting the integrated circuit to the antenna
• CPC Class Codes: G06K 19/07769 the further communication means being a galvanic interface, e.g. hybrid or mixed smart cards having a contact and a non-contact interface
• 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 19/07773 Antenna details antennas for wireless devices, e.g. RFID tags, in general H01Q1/22
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence

Abstract

Laser etching antenna structures (AS) for RFID antenna modules (AM). Combining laser etching and chemical etching. Limiting the thickness of the contact pads (CP) to less than the skin depth (18 m) of the conductive material (copper) used for the contact pads (CP). Multiple antenna structures (AS1, AS2) in an antenna module (AM). Incorporating LEDs into the antenna module (AM) or smartcard (SC).

Claims

1. A method of forming an antenna structure (AS) for an RFID antenna module (AM), comprising:

performing a first etch to etch at least partially through a conductive foil to exhibit tracks separated by spaces, the spaces being the etched portions of the foil, the tracks being the un-etched portions of the foil; and

mounting the foil to a module tape (MT);

wherein the first etch comprises laser ablation.

2. The method of claim 1, wherein the first etch extends at least 70% and no more than 95% through the foil.

3. The method of claim 1, further comprising:

performing a second etch to complete forming the tracks.

4. The method of claim 3, wherein

the first etch comprises laser ablation;

and

the second etch comprises chemical etching.

5. A method of forming an antenna structure (AS) for an RFID antenna module (AM) comprising:

laser etching a copper layer (CL) to form a laser-ablated structure; and

chemical etching the laser-ablated structure,

wherein;

the copper layer has an initial thickness;

the laser etching defines a plurality of tracks, separated by spaces, the spaces extending at least partially through the copper cladding; and

the chemical etching removes less than one-tenth of the initial thickness of the copper layer, slightly increasing the size of the spaces between the tracks.

6. The method of claim 5, wherein:

the tracks form at least a portion of an antenna structure (AS) for the RFID antenna module.

7. The method of claim 5, wherein:

the laser etching proceeds without significantly reducing the overall initial thickness of the copper layer.

8. The method of claim 5, wherein:

the copper layer comprises a conductive foil;

the laser etch extends at least partially through the foil to partially form tracks separated by spaces, the spaces being the etched portions of the layer, the tracks being the un-etched portions of the foil; and

mounting the foil to a module tape (MT).

9. The method of claim 8, wherein the laser etch extends at least 70% and no more than 95% through the foil, to partially form the tracks.

10. The method of claim 8, further comprising:

the chemical etching completes forming the tracks.

11. The method of claim 8, wherein the conductive foil is laser etched only partially through its thickness;

and

a remaining, unetched thickness of the conductive foil supports at least some of the adjacent tracks of the antenna structure (AS).

12. A method of forming an antenna structure (AS) for an RFID antenna module (AM) comprising:

laser etching a copper layer (CL) to form a laser-ablated structure; and

chemical etching the laser-ablated structure,

wherein;

the laser etching defines a plurality of tracks, separated by spaces; and

the chemical etching decreases the thickness of the copper layer and increases the size of the spaces between the tracks;

further comprising;

electroplating the chemically-etched laser-ablated structure, to increase the thickness of the copper layer and to reduce the size of the spaces between tracks.

13. The method of claim 12, wherein:

the tracks form at least a portion of an antenna structure (AS) for the RFID antenna module.

14. The method of claim 12, wherein:

the laser etching proceeds without significantly reducing the overall initial thickness of the copper layer.

15. The method of claim 12, wherein:

the copper layer comprises a conductive foil;

the laser etch extends at least partially through the foil to partially form tracks separated by spaces, the spaces being the etched portions of the layer, the tracks being the un-etched portions of the foil; and

mounting the foil to a module tape (MT).

16. The method of claim 15, wherein the laser etch extends at least 70% and no more than 95% through the foil, to partially form the tracks.

17. The method of claim 15, further comprising:

the chemical etching completes forming the tracks.

18. The method of claim 15, wherein the conductive foil is laser etched only partially through its thickness;

and

a remaining, unetched thickness of the conductive foil supports at least some of the adjacent tracks of the antenna structure (AS).