Method of making a radio frequency identification tag

• US 5,972,156 A
• Filed: 08/21/1997
• Issued: 10/26/1999
• Est. Priority Date: 09/09/1994
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Walker, George Frederick, Heinrich, Harley Kent, Brady, Michael John, Moskowitz, Paul Andrew, Cofino, Thomas, Johnson, Glen Walden
• Primary Examiner(s): Mayes, Curtis
• Application Number:
  US08/915,893
• Time in Patent Office: 796 Days
• Field of Search: 156/166, 156/280, 156/297, 156/300, 340/572, 340/825.54
• US Class Current: 156/280
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00
• 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 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01L 2224/4813 Connecting within a semiconductor or solid-state body, i.e. fly wire, bridge wire
• 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 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• 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 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• 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 9/16 with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole H01Q9/44 takes precedence
• CPC Class Codes: Y10T 156/1089 of discrete laminae to single face of additional lamina
• CPC Class Codes: Y10T 156/1093 with covering of discrete laminae with additional lamina

Abstract

The invention is a radiofrequency identification tag comprising a semiconductor chip having radio frequency, logic, and memory circuits, and an antenna that are mounted on a substrate. The antenna may be used by the chip to modulate an incident RF signal to transfer information to a base station. The antenna comprises one or more lengths of thin wire that are connected directly to the chip by means of wire bonding. The chip and antenna combination are sealed with an organic film covering.

Claims

1. An improved method of making a radio frequency tag which includes a semiconductor device with at least one pair of contacts and an antenna electrically connected to at least one pair of said at least one pair of contacts, the semiconductor device modulating and retransmitting a radio frequency signal received by the antenna, the improved method comprising the steps of:

attaching said semiconductor device to a supporting substrate;

forming said antenna entirely of at least one wire having a diameter in the range of 25 microns to 250 microns by spooling wire from and positioning the spooled wire with a wire bonding machine;

wire bonding said antenna to at least one pair of said at least one pair of contacts of said semiconductor device using said wire bonding machine; and

attaching said antenna for support to said supporting substrate.

2. The improved method of claim 1 wherein said semiconductor device is attached to said supporting substrate by a chip-attaching adhesive.

3. The improved method of claim 1 wherein said antenna is attached to said supporting substrate by a wire-attaching adhesive.

4. The improved method of claim 1 and further comprising the step of encapsulating said semiconductor device and said contact.

5. The improved method of claim 1 and further comprising the step of attaching a top cover to said supporting substrate to entirely enclose said semiconductor device and said antenna between said supporting substrate and said top cover.

6. The improved method of claim 5 wherein said top cover is formed of an organic material.

7. The improved method of claim 5 wherein said top cover includes an outer layer and an inner layer, said outer layer being an organic film and said inner layer being a cover adhesive.

8. The improved method of claim 5 wherein said top cover is attached to said supporting substrate using heat.

9. The improved method of claim 8 wherein said top cover is attached to said supporting substrate using pressure in addition to said heat.

10. The improved method of claim 1 wherein said antenna is formed of a single length of wire spooled from said wire bonding machine.

11. The improved method of claim 1 wherein more than one said radio frequency tag is formed on a single supporting substrate.

12. An improved method of making a radio frequency tag which includes a semiconductor device having at least two contacts and an antenna electrically connected at least to two contacts of said at least two contacts, the semiconductor device modulating and retransmitting a radio frequency signal received by the antenna, the improved method comprising the steps of:

attaching said semiconductor device to a supporting substrate;

forming said antenna entirely of wire having a diameter in the range of 25 microns to 250 microns by spooling wire from and positioning the spooled wire with a wire bonding machine;

wire bonding ends of said antenna to said two contacts of said at least two contacts of said semiconductor device using said wire bonding machine; and

attaching said antenna for support to said supporting substrate.

13. An improved method of making a radio frequency tag which includes a semiconductor device having two contacts and an antenna electrically connected to said two contacts, the semiconductor device modulating and retransmitting a radio frequency signal received by the antenna, the improved method comprising the steps of:

attaching said semiconductor device to a supporting substrate;

forming said antenna entirely of wire having a diameter in the range of 25 microns to 250 microns by spooling wire from and positioning the spooled wire with a wire bonding machine;

wire bonding ends of said antenna to said two contacts of said semiconductor device using said wire bonding machine; and

attaching said antenna for support to said supporting substrate.

14. The improved method of claim 13 wherein said semiconductor device is attached to said supporting substrate by a chip-attaching adhesive.

15. The improved method of claim 13 wherein said antenna is attached to said supporting substrate by a wire-attaching adhesive.

16. The improved method of claim 13 and further comprising the step of encapsulating said semiconductor device and said two contacts.

17. The improved method of claim 13 and further comprising the step of attaching a top cover to said supporting substrate to entirely enclose said semiconductor device and said antenna between said supporting substrate and said top cover.

18. The improved method of claim 17 wherein said top cover is formed of an organic material.

19. The improved method of claim 17 wherein said top cover includes an outer layer and an inner layer, said outer layer being an organic film and said inner layer being a cover adhesive.

20. The improved method of claim 17 wherein said top cover is attached to said supporting substrate using heat.

21. The improved method of claim 20 wherein said top cover is attached to said supporting substrate using pressure in addition to said heat.

22. The improved method of claim 13 wherein said antenna is formed of a single length of wire spooled from said wire bonding machine.

23. The improved method of claim 13 wherein said antenna is formed of a plurality of lengths of wire all spooled from said wire bonding machine.

24. The improved method of claim 13 wherein said antenna includes a length of wire spooled from said wire bonding machine, said length of wire having two ends and said two ends of said wire being wire bonded respectively to different ones of said two contacts of said semiconductor device using said wire bonding machine.