IC card having a mica film for stable resonance frequency and enhanced antenna properties

• US 6,879,258 B2
• Filed: 12/17/2003
• Issued: 04/12/2005
• Est. Priority Date: 07/29/1999
• Status: Expired due to Term

• Current Assignee: Sony Chemicals Corp. (Dexerials Corporation)
• Original Assignee: Sony Chemicals Corp. (Dexerials Corporation)
• Inventors: Kuroda, Nobukazu, Suzuki, Kazuaki
• Primary Examiner(s): Nguyen, Tai T.
• Application Number:
  US10/736,603
• Publication Number:
  US 20040124983A1
• Time in Patent Office: 482 Days
• Field of Search: 340/572.1, 340/572.5, 340/572.7, 340/573.1, 340/573.4, 340/10.33, 340/10.34, 340/10.42
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/162 incorporating printed capacitors

Abstract

An IC card 10A has a mica capacitor that comprises a mica film 1 and electrodes 6a, 6b formed on both sides thereof, where the mica film 1 serves as a mounting substrate for an antenna coil 2 and an IC chip 3, thereby reducing profile of an IC card and also reducing its cost of manufacture and to stabilize its resonance frequency.

Claims

1. An IC card, comprising:

a mica capacitor comprising a mica film acting as a dielectric of said mica capacitor, electrodes formed on both sides of said mica film, an antenna coil, and an IC chip;

wherein;

said mica film acts as a substrate on which said antenna coil and said IC chip are provided, and stablizes a resonant frequency of said IC card as a result of a low water absorption rate of said mica film;

a first capacitor terminal is connected to a first terminal of said IC chip and is linked to a first terminal of said antenna coil;

a second capacitor terminal is connected to a second terminal of said IC chip; and

a third capacitor terminal is connected to a second terminal of said antenna coil; and

said IC chip is mounted on said mica film inside of said antenna coil, such that said IC chip does not overlay said antenna coil.

2. The IC card according to claim 1, wherein said antenna coil and one electrode of said mica capacitor are simultaneously formed by printing a conductive paste on said mica film.

3. The IC card according to claim 1, wherein:

said IC card is sealed with a resin;

said sealed IC card has a first side and a second side;

said first side is laminated with an outer layer film; and

said second side is laminated with a release paper.