JP2000235633A - Non-contact type ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an IC internal damage caused by noise intrusion from an exposed part created by the disconnection of a conductor pattern. SOLUTION: This card is provided with a non-contact type IC 200, a terminal 420 connected to the inner circuit of the IC 200 through a resistance 300 including polysilicon, a terminal 430 connected to the inner circuit through a resistance 310 including polysilicon and a conductor pattern 450 connected between the terminals 420 and 430. The resistances 300 and 310 are made easy to be melted and cut off by connecting the both terminals 420 and 430, to which the pattern 450 is connected, to a circuit part through the resistances 300 and 310 including the polysilicon, the resistances 300 and 310 are melted and cut off before the inner circuit of the IC 200 are destroyed and the part can be made open.

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 having a built-in IC chip.

[0002]

2. Description of the Related Art A conventional electronic tag used in a home delivery system is disclosed in Japanese Patent Application Laid-Open No. HEI 6-115676. This electronic tag has a built-in IC chip for writing and reading information in response to non-contact communication with an external issuing machine. This IC
When the conductive pattern connected between the input terminal and the ground terminal is cut by the punched hole, the chip detects a disconnection state of the conductive pattern based on a change in the voltage level of the input terminal and switches to an active state. The electronic tag is activated by this switching.

[0003]

In the above-mentioned conventional electronic tag, when the conductor pattern is broken by a punch hole, the conductor pattern is exposed to the outside, so that the user is not exposed to the exposed portion. When you get ready, I
There is a problem that the C chip is damaged. In order to solve this problem, US Pat.
No. 1 discloses a technique for strengthening a protection element disposed at an input portion of an IC chip.

However, such a method has a problem that the size of the protection element is increased, which is against the downsizing of the circuit inside the IC, which has progressed with recent miniaturization of LSI. Also, in the non-contact type IC card, the coil portion is virtually grounded by capacitive coupling or inductive coupling with the ground, and noise entering from the exposed portion breaks a weak portion inside the IC via the protection element, resulting in malfunction. There is a problem that causes.

The present invention has been made in view of the above problems, and has as its object to prevent damage to the inside of an IC due to intrusion of noise from an exposed portion due to cutting of a conductor pattern.

[0006]

In order to solve the above problem, according to the first aspect of the present invention, an IC chip (200) provided with an integrated circuit unit for writing and reading information by communicating with the outside is provided. ), A first terminal (420) connected to the integrated circuit section via a first resistor (300) containing polysilicon, and an integrated circuit via a second resistor (310) containing polysilicon. The second connected to the circuit section
(430) and a conductor pattern (450) connected between the first terminal and the second terminal.

As described above, by connecting both terminals to which the conductor pattern is connected to the integrated circuit portion via the first and second resistors including polysilicon, the first and second resistors are connected. Can be easily blown, and the first and second resistors can be blown before the inside of the IC chip is destroyed, and the portion can be opened. For example, as set forth in claim 3, when noise enters through the first and second terminals, it may be set to be blown before the protection element.

More specifically, a rectifier (220) connected between a power supply (120) having a predetermined voltage level and a ground terminal (130), and a rectifier connected in parallel to the rectifier. Carrier extraction circuit (230) and control circuit (2
40) a first and second protection element (250, 260) connected between the power supply and the ground terminal; a first resistor (300) having one end connected to the first protection element; A first terminal (420) connected to the other end of the first resistor;
Resistance (310) having one end connected to the protection element of (310)
And a second terminal (43) connected to the other end of the second resistor.
0), and a conductor pattern (450) connected between the first terminal and the second terminal.
In the non-contact type IC card having the first and second resistors, the first and second resistors are configured to include polysilicon, and when noise enters through the first and second terminals, the first and second resistors are located before the protection element. Can be set to be blown.

[0009] In the invention according to claim 5, the first,
It is characterized in that the wiring for the second protection element is separated from the wiring for the carrier extraction circuit and the control circuit. With such a configuration, noise that has entered through the first and second terminals can pass through a portion different from the carrier extraction circuit and the control circuit. As a result, it is possible to further prevent the internal circuit from being destroyed.

[0010] As described in claim 6, the first and the second
Are both PMOS transistors (250a,
260a) and NMOS transistors (250b, 260
b) may be configured to be connected in series, and the first and second resistors may be connected between the two MOS transistors.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit configuration of a non-contact type IC card 100 to which one embodiment of the present invention is applied. Hereinafter, the circuit configuration of the non-contact type IC card 100 will be described with reference to FIG.

As shown in FIG. 1, a non-contact type IC card 1
00 is a non-contact type IC (integrated circuit unit) in the card 100
200 built-in. The non-contact IC 200 has two terminals 400, 410, 420, 4
30, one of which is a non-contact IC 20.
As a configuration different from that of the non-contact type IC card 100, it is connected to the coil 110 built in the non-contact type IC card 100, and the other side is formed with a conductor pattern (wiring) 450 for forming punched holes.

The non-contact type IC 200 has a capacitor 210 connected in parallel to the coil 110.
A rectifier 220 is connected to both ends of the capacitor 210. The rectifier 220 is connected to the internal power supply 120, and the internal operation of the non-contact type IC 200 can be performed by the voltage rectified by the rectifier 220.

A carrier extraction circuit for extracting a carrier signal and a control circuit for controlling the entire non-contact type IC 200 are connected to an internal power supply 120. further,
The two protection elements 250 and 260 are connected to the internal power supply 120. Specifically, the PMOS transistors 250a and 250 functioning as protection elements are provided to the internal power supply 120.
b and the NMOS transistors 250b and 260b are connected to each other.
Sources and gates of a and 260a are connected to the internal power supply 120, and sources and gates of the NMOS transistors 250b and 260b are connected to the ground terminal. Further, the PMOS transistor 25 of one protection element 250
A resistor 270 is provided so as to connect between the source and the gate of Oa and the drain. Further, a resistor 280 is provided so as to connect between the drain of the other protection element 260 and the GND terminal 130. Then, the PMOS transistor 260a of the protection element 260 and the NMO
The potential between the S transistor 260b and the control circuit 240
To be entered.

The P of the two protection elements 250 and 260
One ends of resistors 300 and 310 are connected between the MOS transistors 250a and 260a and the NMOS transistors 250b and 260b, respectively.
The other ends of 00 and 310 are connected to terminals connected to the conductor pattern 450. These resistors 300 and 310
It is a Poly-Si resistor into which polysilicon is inserted, and is configured to be easily blown.

The operation of the non-contact type IC card 100 thus configured will be described. Non-contact IC card 1
Before the punched hole 500 is formed in the conductor pattern 450 of 00, a power supply voltage divided by the resistors 270, 280, 300, 310, that is, a high-level signal is input to the control circuit 240. Therefore, the non-contact IC 200
Keeps waiting. When the punched hole 500 is formed in the conductor pattern 450, one end of the resistor 280 is connected to G
Because it is connected to the ND terminal 130, the control circuit 2
The input voltage of 40 is zero, that is, a low level signal is input to the control circuit 240, and the non-contact type IC 200 is activated.

When the punched holes 500 are formed in the conductive pattern 450 in this manner, the conductive pattern 450 is exposed from the punched holes 500, so that noise may enter from the exposed portions. In such a case, as described above, the noise is generated by the internal power supply 120 or the GND terminal 13.
0, and by coupling with the ground, the coil 11
0 is a virtual ground, and the internal power supply 120 and the GND terminal 13
There is a possibility that the carrier extraction circuit 230 or the control circuit 240, which is connected to 0, may be broken from a weak point in the circuit. However, in the present embodiment, the resistance 30
Since 0 and 310 are composed of Poly-Si resistors,
When noise enters, the resistors 300 and 310 are blown before the carrier extraction circuit 230 and the control circuit 240 are destroyed, and this part can be opened. Therefore, even if noise enters from the exposed portion of the conductor pattern 450,
The carrier extraction circuit 230 and the control circuit 240 can be prevented from being destroyed.

In such a case, the resistors 300, 31
Until the 0 is blown, the carrier extraction circuit 230 and the control circuit 240 need only be able to withstand noise. Therefore, it is not necessary to increase the size of the carrier extraction circuit 230 and the control circuit 240 to improve the durability. (Second Embodiment) FIG. 2 shows a circuit configuration of a non-contact type IC card 100 according to a second embodiment of the present invention. Less than,
The circuit configuration of the non-contact type IC card 100 will be described with reference to FIG. 2. However, since the configuration is almost the same as that of the first embodiment, only different configurations will be described.

As shown in FIG. 2, according to the present embodiment, the second power supply 120 is disposed between the internal power supply 120 and the GND terminal 130.
The routing paths of the two protection elements 250 and 260 are separated from other internal circuits (the carrier extraction circuit 230 and the control circuit 240). In such a configuration, the intruded noise does not pass through the carrier extraction circuit 230 or the control circuit 240, and passes through the coil 110 via the rectifier 220.
The influence of the noise on the carrier extraction circuit 230 and the control circuit 240 can be further reduced.

(Third Embodiment) FIG. 3 shows a circuit configuration of a non-contact type IC card 100 according to a third embodiment of the present invention. The contactless IC card 100 according to the present embodiment
The resistors 270 and 280 of the non-contact type IC card 100 according to the second embodiment are replaced by MOS transistors 270a and 280.
a.

As described above, the resistors 270 and 280 are
In the case where the MOS transistors 270a and 280a are configured by the transistors 270a and 280a,
Since the MOS transistors 270a and 280a can be turned on and off by controlling the gate applied voltage of a, a configuration in which no current always flows between the internal power supply 120 and the GND terminal 130 can be realized.

(Other Embodiments) In each of the above embodiments, in order to easily blow the resistors 300 and 310, the resistors 300 and 310 are bent and routed on a layout so that electric field concentration occurs at a corner portion. , The wiring width of the resistors 300 and 310 can be locally reduced.

In each of the above embodiments, the punched hole 50
Although the description has been given of an example in which the conductor pattern 450 is cut by 0, other methods, such as adding a perforated mesh and cutting the perforated portion, to disconnect the conductor pattern 450. It may be.
In the above embodiment, the non-contact type IC card which detects the operating state by cutting the conductor pattern 450 has been described. However, the present invention is applied to the non-contact type IC card which uses the terminals 420 and 430 as detection terminals. You may. further,
The present invention may be applied to a non-contact type IC card that inputs signals using the terminals 420 and 430.

[Brief description of the drawings]

FIG. 1 is a diagram showing a circuit configuration of a non-contact type IC card 100 according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a circuit configuration of a non-contact type IC card 100 according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a circuit configuration of a non-contact type IC card 100 according to a third embodiment of the present invention.

[Explanation of symbols]

100: non-contact type IC card, 110: coil, 200
... non-contact type IC, 210 ... capacity, 220 ... rectifier, 23
0: carrier extraction circuit, 240: control circuit, 250, 2
60 ... protection element, 270, 280 ... resistance, 300, 31
0: resistance including Poly-Si, 420, 430: terminal, 450: conductor pattern, 500: punch hole.

Claims (6)

[Claims] An IC chip (2) provided with an integrated circuit unit for writing and reading information by communication with the outside.
00), via a first resistor (300) containing polysilicon, a first terminal (420) connected to the integrated circuit section, and via a second resistor (310) containing polysilicon. , A second terminal (430) connected to the integrated circuit portion, and a conductor pattern (450) connected between the first terminal and the second terminal. Contactless IC card. 2. The method according to claim 1, wherein a disconnection of the conductor pattern is detected based on a change in a potential level at one of the first and second terminals, and the conductor pattern is switched to an active state based on the detection of the disconnection. Contact type IC card. 3. The first and second resistors are connected to first and second protection elements (250, 260), respectively, when noise enters through the first and second terminals. 3. The non-contact type IC card according to claim 1, wherein the non-contact type IC card is set to be blown before the protection element. 4. A rectifier (220) connected between a power supply (120) at a predetermined voltage level and a ground terminal (130).
And a carrier extraction circuit (23) connected in parallel with the rectifier.
0) and a control circuit (240), and first and second protection elements (250, 250) connected between the power supply and the ground terminal.
260); a first resistor (300) having one end connected to the first protection element; a first terminal (420) connected to the other end of the first resistor; And a second terminal (430) connected to the other end of the second resistor.
And a conductor pattern (450) connected between the first terminal and the second terminal. The first and second resistors are poly A non-contact type IC comprising silicon and being set to be blown earlier than the protection element when noise enters through the first and second terminals. card. 5. The non-contact type IC according to claim 4, wherein the wiring for the first and second protection elements is separated from the wiring for the carrier extraction circuit and the control circuit. card. 6. The first and second protection elements are both PM
An OS transistor (250a, 260a) and an NMOS transistor (250b, 260b) are connected in series, and the first and second resistors are connected between the two MOS transistors. The non-contact type IC card according to any one of claims 3 to 5, wherein