Non-contact IC card

• US 5,321,240 A
• Filed: 01/25/1993
• Issued: 06/14/1994
• Est. Priority Date: 01/30/1992
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Takahira, Kenichi
• Primary Examiner(s): PITTS, HAROLD I
• Application Number:
  US08/008,507
• Time in Patent Office: 505 Days
• Field of Search: 235/380, 235/439, 235/451, 235/492
• US Class Current: 235/380
• 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 19/07749 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 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: H05K 2201/2009 Reinforced areas, e.g. for a specific part of a flexible printed circuit
• CPC Class Codes: H05K 2201/2018 Presence of a frame in a printed circuit or printed circuit assembly
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence

Abstract

A non-contact IC card has a high mechanical strength with respect to bending and twisting, although thin, yet allows the mounting area of a circuit board to be effectively used. A highly rigid, electrically-conducting reinforcing frame is disposed on the outer edge of a circuit board to increase the mechanical strength of the card with respect to bending and twisting. Further, the reinforcing frame is electrically connected to conductor patterns of a spiral coil on the circuit board having an inductance L in an antenna circuit.

Claims

1. A non-contact IC card for exchanging signals with an external apparatus by means of electromagnetic waves comprising:

a circuit board;

circuitry centrally mounted on said circuit board for data processing, control, and storage;

an electrically-conductive reinforcing frame along an outer edge of said circuit board around said circuitry, said electrically-conductive reinforcing frame having a gap;

an antenna circuit electrically connected to said circuitry and comprising a spiral coil along said outer edge of said circuit board and electrically connected in series with said electrically-conductive reinforcing frame and a capacitor on said circuit board at said circuitry, said spiral coil and said electrically-conductive reinforcing frame together having an inductance L and said capacitor having a capacitance C; and

a casing of a non-electrically-conductive material encapsulating said circuit board, circuitry, and reinforcing frame.

2. The non-contact IC card according to claim 1 wherein said circuit board has opposing first and second major surfaces, said circuitry being disposed on one of said major surfaces of said circuit board, said spiral coil of said antenna circuit comprising a pair of conductor patterns disposed on respective outer peripheral locations of said first and second major surfaces of said circuit board, said electrically-conductive reinforcing frame comprising a U-shaped reinforcing frame extending along said outer edge of said circuit board, said U-shaped reinforcing frame having a longitudinal recess in which said outer edge of said circuit board is received, said conductor pattern on said first major surface of said circuit board, said U-shaped reinforcing frame, and said conductor pattern on said second major surface of said circuit board being electrically connected in series.

3. The non-contact IC card according to claim 1 wherein said circuit board has opposing first and second major surfaces, said circuitry being disposed on one of said major surfaces of said circuit board, said spiral coil of said antenna circuit comprising a pair of conductor patterns disposed on respective outer peripheral locations of said first and second major surfaces of said circuit board, said electrically-conductive reinforcing frame comprising bar-shaped reinforcing frame elements extending along said outer edge of said circuit board and including gaps, said bar-shaped reinforcing frame elements holding therebetween said circuit board at said first and second major surfaces, said bar-shaped reinforcing frame elements and said conductor patterns on said first and second major surfaces of said circuit board being electrically connected in series successively from said first major surfaces of said circuit board to said second major surface of said circuit board as a single coil structure.

4. The non-contact IC card according to claim 1 wherein said electrically-conductive reinforcing frame is one of stainless-steel-based and duraluminum-based material.