JPH08216571A - Ic card - Google Patents

Abstract

PURPOSE: To obtain a small-size, thin, wide-band inexpensive non-contact type IC card by a method wherein an antenna is composed of a conductor formed on a thin plastic film and a U-shaped ground conductor surrounding the conductor. CONSTITUTION: On a surface of a plastic film, a conductor D1 and a ground conductor D2 are formed using conductive ink by screen printing. On the surface, a spacer is laminated, which is a plastic film provided with a relief hole on a position corresponding to an IC and coated with an adhesive on the back surface thereof. Lastly, plastic films each coated with an adhesive are laminated as upper and lower layers for forming a non-contact type IC card. In this manner, since the ground conductor is formed to be flush with the conductor, the band is hardly remarkably reduced in width even in a thin IC card.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type IC card.

[0002]

2. Description of the Related Art Non-contact type IC cards are classified into an electromagnetic coupling type, an electromagnetic induction type, a radio wave type and the like depending on the transmission medium. Among them, the radio wave method is used for those requiring a relatively long communication distance, and the built-in antenna is generally an antenna having a half wavelength at the used frequency.

[0003]

Such a non-contact type I
The C card has the same size and thickness as those of the CD card (ISO standard 84.
5 mm x 54.0 mm x 0.8 mm) is required,
Depending on the frequency used, it may not be possible to form within the size of an ordinary 1/2 wavelength antenna,
Further, there are various problems such that a microstrip antenna or the like having a ground conductor on its back surface has an extremely narrow band characteristic when it is made thin. An object of the present invention is to provide an IC card having an antenna that is excellent in size and thickness, has a wide band, and can be inexpensively constructed.

[0004]

As shown in FIG. 1, an IC card of the present invention has a conductor D1 formed on a thin plastic film and a U-shape formed so as to surround the conductor D1. The antenna is composed of the ground conductor D2. This U-shaped antenna is an ordinary slot antenna in which both ends are electrically released and deformed into a U-shape, whereby the length L1 of the antenna is 1/4 wavelength of the used frequency. The following is possible, and since the ground conductor is formed not on the back surface but on the same plane as the conductor, an extremely narrow band is unlikely to occur even in a thin shape such as an IC card.

Further, as shown in FIG. 2, the conductor D1 and the ground conductor D2 may be connected by capacitors C1 and C2. As a result, the length L2 of the antenna can be further shortened and the size can be reduced. Furthermore, the conductor D1
The ground conductor D2 may be formed using so-called conductive ink. Thereby, not only the cost can be reduced as compared with the general etching method, but also the resistance of the conductor is increased, so that the band can be widened.

[0006]

EXAMPLE As shown in FIG. 1, a conductor D1 and a ground conductor D2 were formed on the surface of a PET film by screen printing with conductive ink, and an IC was mounted on the surface by using an anisotropic conductive film. . Further, an escape hole was formed on the surface corresponding to the IC, and a spacer made of a PET film coated with an adhesive was laminated on the back surface. Finally, a PET film coated with an adhesive is laminated on these upper and lower layers, and the non-contact type I
A C card was formed.

[0007]

As described above, according to the present invention, a non-contact type IC which is excellent in small size and thin shape, has a wide band and is inexpensive.
Realization of a card becomes possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing another embodiment of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Kaneko 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (3)

[Claims] 1. An IC card comprising an antenna, an electronic component such as an IC and a capacitor, a connecting member for electrically connecting them, and a covering member made of a plastics film, a sheet or the like. Conductor D1 formed on the plastic film and the conductor D1
An IC card comprising a U-shaped ground conductor D2 formed so as to surround 1. 2. A U-shaped tip portion of the antenna,
The IC card according to claim 1, wherein the conductor D1 and the ground conductor D2 are connected by capacitors C1 and C2. 3. The IC card according to claim 1, wherein the conductor D1 and the ground conductor D2 of the antenna are formed by using a so-called conductive ink.