Structures and assembly methods for radio-frequency-identification modules

• US 6,696,952 B2
• Filed: 08/03/2001
• Issued: 02/24/2004
• Est. Priority Date: 08/04/2000
• Status: Expired due to Fees

• Current Assignee: HEI, Inc.
• Original Assignee: HEI, Inc.
• Inventors: Zirbes, Glen
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/922,245
• Publication Number:
  US 20020044057A1
• Time in Patent Office: 935 Days
• Field of Search: 340/572.1, 340/572.7, 361/813, 257/666
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/041 Constructional details G06K19/06 takes precedence
• 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

Abstract

Radio-frequency identification (RFID) devices are used in a variety of applications to facilitate the identification and tracking of people, objects, and animals. One problem with RFID devices or tags concerns manufacturing cost. Specifically, some tag designs use an integrated-circuit chip requiring three external connections, instead of two as do many other designs. Accordingly, the present inventor devised a unique RFID module which uses a three-terminal integrated circuit and two capacitors, but only requires two external leads. One exemplary embodiment of the module includes two external terminals for connection to an antenna coil and an internal terminal for connection to a center-tap of a dual (center-tapped) capacitor. Other aspects of the invention include subcomponents of the module and methods of tag assembly using the module.

Claims

1. A lead frame for use in making a radio-frequency-identification module, the lead frame including:

first and second recessed regions for receiving first and second chips; and

at least three contact pads, with at least two of the pads for connection to components external to the module.

2. A lead frame for use in making a radio-frequency-identification module, the lead frame including:

a first conductive structure having a first body portion and a first extended portion, with the first extended portion for extension outside the module and connection to an antenna coil;

a second conductive structure having a second body portion and a second extended portion, with the second extended portion for extension outside the module and connection to the antenna coil; and

a third conductive structure completely separated from the first and second conductive structures and for connection to one or more contact pads inside the module.

3. The lead frame of claim 2, wherein the first conductive structure includes a recessed region for receiving an integrated-circuit chip.

4. The lead frame of claim 2, wherein the third conductive structure is between the first and second conductive structures.

5. A radio-frequency-identification module comprising:

first and second electrically connected chips, with one of the chips including an external terminal and at least two capacitors, with each of the capacitors coupled to the external terminal; and

first and second external leads electrically coupled to the first and second chips, with the external leads for connection to an antenna coil.

6. The module of claim 5, further comprising:

an insulative housing enclosing the first and second electrically connected chips.

7. The module of claim 5, wherein the first chip comprises a wireless-communications circuit and a memory.

8. The module of claim 5, wherein the two capacitors define a center-tapped capacitor.

9. The module of claim 5, further comprising a lead frame including first and second recessed regions and at least three contact pads, with the first and second chips mounted respectively to the first and second recessed regions, and at least two of the pads for connection to the antenna coil and one of the pads coupled to the external terminal.

10. The module of claim 5, further comprising a lead frame, wherein the lead frame includes:

a first conductive structure having a first body portion mounted to the first chip and a first extended portion for extension outside the module and connection to the antenna coil;

a second conductive structure having a second body portion mounted to the second chip and a second extended portion for extension outside the module and connection to the antenna coil; and

a third conductive structure completely separated from the first and second conductive structures and electrically coupled to the external terminal.

11. A radio-frequency-identification module comprising:

a lead frame having at least first, second, and third separate contact regions, with the first and second contact regions for connection to an antenna coil;

an RFID chip fixed relative to the first contact region;

a capacitor chip fixed relative to the second contact region and having at least first, second, and third terminals;

a first electrical connection between the first terminal and the first contact region;

a second electrical connection between the second terminal and the second contact region; and

a third electrical connection between the third terminal and the third contact region.

12. The module of claim 11, wherein the RFID chip and the capacitor chip are attached respectively to the first and second contact regions.

13. The module of claim 11, wherein the capacitor chip includes a center-tapped capacitor.

14. An assembly comprising:

an antenna coil having first and second conductive portions; and

the module of claim 11, wherein the first and second contact regions are coupled respectively to the first and second conductive portions.