Contactless smartcards with multiple coupling frames
A smartcard (SC) having at least a contactless interface, such as having a dual interface transponder chip module (TCM) with a chip (IC), a module antenna (MA) for the contactless interface, and contact pads (CP) for a contact interface. Metal layers (ML) may have openings (MO) for receiving the module, and slits (S) or nonconductive stripes (NCS) extending to the openings, thereby forming coupling frames (CF). A card body (CB) for the smartcard may comprise two such metal layers (front and rear coupling frames) separated by a layer of non-conductive (dielectric) material. A front face card layer and a rear face card layer may complete a multiple coupling frame stack-up for a smartcard.
1. Smartcard having at least a contactless interface, comprising:
two coupling frames (CF- 1 , CF- 2 ) separated by a dielectric layer wherein each coupling frame comprises:
a metal layer having an opening (MO- 1 , MO- 2 ) for receiving a transponder chip module (TCM) having a module antenna (MA, LES); and
a discontinuity comprising a slit (S) or a non-conductive stripe (NCS), extending from the opening to a periphery of the metal layer.
2. The smartcard of claim 1 , wherein:
the metal layers comprises a material selected from the group consisting of copper, aluminum, brass, titanium, tungsten, stainless steel, silver, graphene, silver nanowires, and conductive carbon ink.
3. The smartcard of claim 1 , wherein:
the slit of one of the two coupling frames is arranged in a different direction than the slit of another of the two coupling frames.
4. The smartcard of claim 1 , wherein:
the slits of the two coupling frames in different directions from their respective module openings, so that the slit of one coupling frame may be supported by an area without a slit of the other coupling frame.
5. The smartcard of claim 1 , wherein:
when the transponder chip module is disposed in the opening, a portion of at least one of the two coupling frames overlaps at least a portion of the module antenna.
6. The smartcard of claim 1 , further comprising:
a transponder chip module (TCM) disposed in the opening;
wherein the slit (S) or non-conductive stripe (NCS) of at least one of the two coupling frames overlaps at least a portion of the module antenna.
7. The smartcard of claim 1 , wherein, for a given one of the two coupling frames:
the discontinuity is a slit; and
the slit extends completely through the metal layer, and is at least partially filled with an electrically non-conducting material selected from the group consisting of polymer and epoxy resin, and reinforced epoxy resin.
8. The smartcard of claim 1 , wherein:
the smartcard is dual interface, having both contact and contactless interfaces.
9. The smartcard of claim 1 , further comprising:
a transponder chip module (TCM);
wherein:
a first of the coupling frames (CF- 1 ) surrounds the top, left and bottom edges of the transponder chip module (TCM), and extends to the top, left and bottom edges of the card body (CB), and has a module opening (MO- 1 ) for the transponder chip module (TCM); and
a second of the coupling frames (CF- 2 ) surrounds the top, right and bottom edges transponder chip module (TCM), and extends to the top, right and bottom edges of the card, and has a module opening (MO- 2 ).
10. The smartcard of claim 9 , wherein:
in aggregate, the two coupling frames cover nearly the entire surface of the card body.
11. The smartcard of claim 1 , wherein:
one of the coupling frames (CF- 1 ) is a front coupling frame; and
the other coupling frame (CF- 2 ) is a rear coupling frame.
12. The smartcard of claim 11 , further comprising:
a front face card layer; and
a rear face card layer.
13. Contactless smartcard comprising two metal layers separated by a dielectric layer wherein:
each metal layer has an opening for receiving a transponder chip module and a discontinuity comprising a slit (S) or a non-conductive stripe (NCS), extending from the opening to a periphery of the metal layer.
14. The contactless smartcard of claim 13 , wherein the slits are oriented in different directions than one another.
15. The contactless smartcard of claim 13 , further comprising:
a transponder chip module disposed in the openings.
16. The contactless smartcard of claim 15 , wherein the transponder chip module comprises a dual interface chip.