Inductively powered transponder device

• US 20070096910A1
• Filed: 07/14/2006
• Published: 05/03/2007
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Waters, John
• Granted Patent: US 7,492,260 B2
• Time in Patent Office: Days
• 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: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32188 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/83851 being an anisotropic conductive adhesive
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01055 Cesium [Cs]
• CPC Class Codes: H01L 2924/0665 Epoxy resin
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/351 Thermal stress

Abstract

An inductively powered transponder device has an unpackaged integrated circuit in which is integrated an antenna for receiving power and signal from radio frequency transmissions. A heatsink is thermally connected to the integrated circuit. The heatsink has means to prevent eddy currents. A first layer and a second layer of web material are attached together to encapsulate the integrated circuit and the heatsink.

Claims

1. An inductively powered transponder device comprises:

an unpackaged integrated circuit in which is integrated an antenna for receiving power and signal from radio frequency transmissions;

a heatsink thermally connected to the integrated circuit and having means to prevent eddy currents; and

a first layer and a second layer of web material attached together to encapsulate the integrated circuit and the heatsink.

2. An inductively powered transponder device as claimed in claim 1 wherein the heatsink comprises a metallic layer and the means to prevent eddy currents comprises one or more slots in the metallic layer.

3. An inductively powered transponder device as claimed in claim 2 wherein the metallic layer extends over the whole surface of the unpackaged integrated circuit to which it is adjacent.

4. An inductively powered transponder device as claimed in claim 2 wherein the heatsink comprises a metallization formed on one of the first layer and the second layer.

5. An inductively powered transponder device as claimed in claim 2 wherein the heatsink comprises a freestanding metallic element.

6. An inductively powered transponder device as claimed in claim 2, wherein the heatsink is formed substantially of copper.

7. An inductively powered transponder device as claimed in claim 1 wherein one or both of the first layer and the second layer are formed substantially of paper.

8. An inductively powered transponder device as claimed in claim 1 wherein one or both of the first layer and the second layer are formed substantially of a plastics material.

9. An inductively powered transponder device as claimed in claim 1 wherein the heatsink is electrically connected to a ground plane of the unpackaged integrated circuit.

10. An inductively powered transponder device as claimed in claim 1 wherein the heatsink is electrically insulated from the unpackaged integrated circuit.

11. An inductively powered transponder device as claimed in claim 1 wherein the unpackaged integrated circuit comprises functionality of a memory tag.

12. A method of manufacturing an inductively powered transponder device, comprising:

providing a first layer of web material;

forming a heatsink layer, having means to prevent eddy currents, on the first layer;

attaching an unpackaged integrated circuit with an antenna for receiving power and signal from radio frequency transmissions on the heatsink layer;

providing a second layer of web material over the first layer such that the heatsink layer and the unpackaged integrated circuit lie therebetween; and

encapsulating the heatsink layer and the unpackaged integrated circuit between the first layer and the second layer.

13. A method as claimed in claim 12 wherein forming a heatsink layer comprises forming a metallization on a part of one surface of the first layer.

14. A method as claimed in claim 12 wherein forming a heatsink layer comprises bonding a freestanding metallic element to the first layer.

15. A method as claimed in claim 12, wherein a metallic layer of the heatsink extends over the whole surface of the unpackaged integrated circuit to which it is adjacent.

16. A method as claimed in claim 12, wherein the means to prevent eddy currents comprises one or more slots formed in the heatsink layer.

17. A method as claimed in claim 12, wherein the heatsink layer is bonded with an epoxy to the unpackaged integrated circuit.

18. A method as claimed in claim 12, wherein one or both of the first layer and the second layer are formed substantially of paper.

19. A method as claimed in claim 12, wherein one or both of the first layer and the second layer are formed substantially of a plastics material.

20. A method as claimed in claim 12, wherein a plurality of inductively powered transponder devices are formed together on an extended length of the first material and wherein the inductively powered transponder devices are separated from each other at or after the encapsulation step.

21. A memory tag comprising an unpackaged integrated circuit with an antenna and adapted to receive power and signal from radio frequency transmissions, the unpackaged integrated circuit being in thermal contact with a heatsink having means to prevent eddy currents, wherein the unpackaged integrated circuit and the heatsink are encapsulated between two layers of a web material.

22. A memory tag as claimed in claim 21, having attachment means to allow the memory tag to be affixed to a surface as a label.