Smart cards having thin die

• US 5,719,437 A
• Filed: 04/19/1996
• Issued: 02/17/1998
• Est. Priority Date: 04/19/1996
• Status: Expired

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Clifton, Mark Bradford, Flynn, Richard Michael, Verdi, Fred William
• Primary Examiner(s): Crane, Sara W.
• Assistant Examiner(s): Abraham, Fetsum
• Application Number:
  US08/635,072
• Time in Patent Office: 669 Days
• Field of Search: 257/669, 257/672, 257/679, 257/728, 257/782
• US Class Current: 257/679
• CPC Class Codes: G06K 19/07728 the record carrier comprising means for protection against impact or bending, e.g. protective shells or stress-absorbing layers around the integrated circuit
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Thin semiconductor die, approximately 0.004 to 0.007 inches thick, are positioned substantially on the neutral plane of a smart card, the neutral plane defined as the plane of substantially no mechanical strain during flexure of the smart card, thereby providing smart cards having improved resistance to mechanical flexure, and/or smart cards having improved RF performance.

Claims

1. A semiconductor die for use in a smart card, characterized in that the semiconductor die is less than 0.008 inches thick.

2. A semiconductor die for use in a smart card, characterized in that:

(a) the semiconductor die is less than 0.008 inches thick; and

(b) the semiconductor die includes an active device equipped to operate at an RF frequency greater than 20 Khz.

3. A smart card including:

(a) a memory device, and/or

(b) a processing device,

wherein the memory device and the processing device are fabricated using a semiconductor die having a thickness of 0.008 inches or less.

4. A smart card including:

(a) a memory device, and/or

(b) a processing device,

wherein the memory device and the processing device are fabricated using a semiconductor die having a thickness of 0.008 inches or less, and wherein the processing device operates at a speed greater than or equal to 4.0 MHz.

5. A semiconductor die for use in a smart card package having a neutral plane defined as the plane of substantially zero mechanical strain during mechanical flexure of the smart card package, characterized in that:

(a) the semiconductor die is less than 0.008 inches thick, and

(b) at least a portion of the semiconductor die is positioned within the neutral plane of the smart card package.

6. A semiconductor die as set forth in claim 5 further including a plurality of diodes and transistors defining an active surface within the semiconductor die, the active surface being positioned within the neutral plane of the smart card package.

7. A semiconductor die as set forth in claim 5 further including a plurality of diodes and transistors defining an active surface within the semiconductor die, the active surface being positioned within the neutral plane of the smart card package, and at least one of the plurality of transistors adapted for operation at an RF frequency greater than 20 KHz.