Non-contact IC card

Details Non-contact IC card Non-contact IC card

2000-01-05

2002-06-11

Gandhi, Jayprakash N. (Department: 2841)

Electricity: electrical systems and devices

Housing or mounting assemblies with diverse electrical...

For electronic systems and devices

C361S803000, C361S820000, C235S492000, C257S679000

Reexamination Certificate

active

06404644

ABSTRACT:

This application is a National Stage Application of International Application PCT/JP98/02540, with an international filing date of Jun. 8, 1998, the disclosure of which is incorporated into this application by reference.
TECHNICAL FIELD
The present invention generally relates to a non-contact IC card. More specifically, the present invention relates to a non-contact type IC card without a power supply source for transmission/reception of an electric signal to/from an external data processing apparatus by converting a radio wave received by a self-contained antenna coil to electric power.
BACKGROUND ART
A non-contact type IC card has been proposed and recently used which is provided with a semiconductor integrated circuit device (IC) for storing information (data) and transmits/receives information to/from an external data processing apparatus which utilizes or supplies the information in a non-contact state.
Such non-contact type IC card is used, for example, as a pass of the ski lift, a commuter's pass for a train or bus, a tag for administration of inventory and the like, in an information management system.
In the information management system using the non-contact IC card, information is transmitted by an electromagnetic wave (hereinafter referred to as an RF carrier). An external apparatus modulates the RF carrier and transmits a command or information. The IC card is provided with a tuning circuit including a coil as an antenna for receiving the modified RF carrier and a capacitor.
The IC card demodulates the modulated RF carrier transmitted by the external apparatus for obtaining the command or information and, changes an impedance of the tuning circuit by a signal representing information to be returned in a period during which RF carrier is not modulated. The change in the impedance modulates the RF carrier. The external apparatus receives and demodulates the modulated RF carrier to obtain information from the IC card.
Preferably, the IC card can semi-eternally be used and thin. Thus, the IC card receives electric power from the RF carrier rather than having a power supply source with a limited lifetime.
Transmission of information and supply of electric power can be performed by the same RF carrier. When transmission of information and supply of electric power are performed by the same RF carrier, one tuning circuit is provided in the IC card. When transmission of information and supply of electric power are performed by different RF carriers, two tuning circuits are provided in the IC card.
FIGS. 7 and 8
are diagrams showing conventional IC cards.
Referring to
FIG. 7
, an IC card
100
is provided with an IC chip
111
, one tuning circuit
114
, and a capacitor
115
for storing (smoothing) electric power obtained by an RF carrier.
Tuning circuit
114
is connected to IC chip
111
. Tuning circuit
114
has a coil
112
as an antenna for receiving the RF carrier, and a capacitor
113
for resonance connected in parallel with the coil. Capacitor
115
is also connected to IC chip
111
.
In such IC card
100
, information is transmitted and electric power is supplied from an external apparatus to tuning circuit
114
including a coil
112
and capacitor
113
. The supplied electric power is stored in capacitor
115
through IC chip
111
.
Referring to
FIG. 8
, an IC card
200
is provided with an IC chip
221
, two tuning circuits
224
and
229
and a capacitor
225
for storing (smoothing) electric power obtained by an RF carrier. Tuning circuit
224
has a coil
222
as an antenna for receiving the RF carrier, and a capacitor
223
for resonance connected in parallel with coil
222
. Tuning circuit
224
is supplied with electric power from an external apparatus by receiving the RF carrier.
Tuning circuit
229
has a coil
227
as an antenna for receiving the RF carrier, and a capacitor
228
for resonance connected in parallel with coil
227
. Coil
227
of tuning circuit
229
receives the RF carrier for data transmission with respect to the external apparatus.
Tuning circuits
224
and
229
and capacitor
225
are connected to IC chip
221
. When tuning circuit
224
is supplied with electric power from the external apparatus, the electric power is stored in capacitor
225
through IC chip
221
.
FIG. 9
is a plan view showing the IC card in
FIG. 7
, and
FIG. 10
is a cross sectional view taken along the line B—B in FIG.
9
. Referring to
FIGS. 9 and 10
, IC card
100
is provided with a substrate
110
, a coil
112
, an IC chip
111
as a semiconductor device and capacitors
113
and
115
. Coil
112
of a conductor is formed on substrate
110
. Coil
112
has a coil outer end
112
a
and a coil inner end
112
b.
IC chip
111
as a semiconductor device is formed above substrate
110
. IC chip
111
has a main surface
111
c
facing substrate
110
. Main surface
111
c
has terminals
111
a
and
111
b
. Terminal
111
a is electrically connected to coil outer end
112
a
. Terminal
111
b is electrically connected to a coil inner end
112
b
which is on the inner side
112
c
of the coil by an interconnection
153
via through holes
151
and
152
formed in substrate
110
.
IC chip
111
is electrically connected to capacitors
113
and
115
which are on the outer side
112
d
of the coil by an interconnection
157
. A thin plate of resin (not shown) is formed on substrate
110
to cover coil
112
, IC chip
111
, capacitors
113
and
115
and the like. It is noted that inner or outer ends of two coils
222
and
227
are connected to a terminal of IC chip
221
via a through hole formed in the substrate and a back surface of the substrate also in IC card
220
having two tuning circuits
224
and
229
shown in FIG.
8
.
In IC card
100
having the above described structure, terminal
111
b
and coil inner end
112
b
are electrically connected by interconnection
153
via through holes
151
and
152
. Thus, interconnection
153
is not brought into contact with coil
112
except at coil outer end
112
b
or with capacitors
113
and
115
. Therefore, a problem associated with a short-circuit is prevented.
However, such IC card
100
requires a step of forming through holes
151
and
152
and a step of forming interconnection
153
on the surface opposite to that at which coil
112
and IC chip
111
are formed. Further, a step of filling through holes
151
and
152
with metal for interconnection by vapor deposition is required. This makes a manufacturing process complicated and undesirable in terms of efficiency and cost.
As IC card
100
is thin and flexible, interconnection
153
is likely to be broken in through holes
151
and
152
, thereby causing malfunction.
It is noted that although IC chip
111
is provided on the outer side
112
d
of the coil in IC card
100
shown in
FIG. 9
, IC chip
111
may be provided on the inner side
112
c
of the coil. However, also in this case, a through hole must be formed to electrically connect coil outer end
112
a
and terminal
111
a
of IC chip
111
. As a result, the problem associated with the complicated manufacturing process and malfunction is caused.
To solve these problems, main surface
111
c
of IC chip
111
with terminals
111
a
and
111
b
may be formed as an upside in
FIG. 10
, where terminals
111
a
and
111
b
are electrically connected to coil outer and inner ends
112
a
and
112
b
by bonding wires, respectively. Such structure eliminates the need for a through hole and the manufacturing process is not complicated.
However, the bonding wire electrically connecting terminal
111
b
and coil inner end
112
b
crosses over coil
112
, and therefore the bonding wire may be brought into contact with coil
112
and causes malfunction. Further, as a length of the bonding wire connecting terminal
111
b
and coil inner end
112
b
is large, external force may break the wire to cause malfunction.
Therefore, the present invention is made to solve the aforementioned problems. An object of the present invention is to provide a non-contact IC card which can readily be manufactured and

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