JPH07296332A - Magnetoresistance effect head and its manufacture and magnetic stripe information reader using magnetoresistance effect head - Google Patents

Abstract

PURPOSE:To obtain a magnetoresistance effect head which can be realized by a simple manufacturing process. CONSTITUTION:An electrode thin film 11 is formed on a substrate 10 by a sputtering method and a magnetoresistance effect thin film 12 is formed on the electrode thin film 11 by sputtering. Array-type electrodes 13 are formed on the magnetoresistance effect thin film 12 by photolithography.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head, a method of manufacturing the same, and a magnetic stripe information reading apparatus using the magnetoresistive head, for reading magnetic stripe information such as a magnetic card. Is.

[0002]

2. Description of the Related Art In recent years, magnetic cards and the like have become popular. FIG. 2 shows an outline of a process of reading magnetic stripe information of a general magnetic card or the like. In FIG. 2, the magnetic stripe portion 2 of the magnetic card 1 is formed of a magnetic recording medium such as Fe ₂ O ₃ . Further, the reader 3 is provided with an electromagnetic induction type magnetic head 4. Then, as a reading process, necessary information is recorded in advance in the magnetic stripe portion 2, and the magnetic card 1 is inserted into the reading device 3.

At this time, from the viewpoint of accurate reading of information, reading is performed with the entire magnetic card 1 inside the device. Then, by moving either the magnetic card or the magnetic head, magnetic information is read by the magnetic head by an electromagnetic induction method.

However, FIG. 2 is an explanatory diagram of the reading movement in the case of moving only the magnetic card.
Finally, the magnetic card is ejected to end the reading process.

As another magnetic stripe information reading method, there is a method using a magnetoresistive head.
Regarding the technology of this magnetoresistive (MR) element,
For example, Reference: 1992, Journal of Japan Applied Magnetics Society, Vol. 16, No. 1 pages 29-35, "MR (magnetoresistive) element for magnetic encoder".

In addition to the method of using the magnetoresistive effect element as a substitute for the detection coil of the magnetic head 4 of the electromagnetic induction type shown in FIG. There is a method to read the card.

In this case, the magnetic card and the read head can read in a stationary state, and it has been possible to realize the downsizing of the device and the simplification of the reading mechanism.

[0008]

As described above, when an electromagnetic induction type magnetic head is used in a magnetic stripe information reading apparatus such as a magnetic card, at least one of the magnetic card and the magnetic head is read. Sometimes it was necessary to move it, and the size of the device and the complicated mechanism were required.

Therefore, in order to realize the miniaturization of the device and the simplification of the reading mechanism, a magnetoresistive head having magnetoresistive elements arranged in an array is effective. Therefore, FIGS. 3 and 4 show configuration diagrams of the magnetoresistive head. In FIG. 3, a detection method when the magnetoresistive effect elements are wired in parallel is shown. And FIG.
The voltage across the fixed resistor R in the detection IC of the
.., S2, ..., the change in the current flowing through each element of the magnetoresistive effect elements MR1, MR2 ,.

In this case, since the resistance change rate of the magnetoresistive material is generally as small as about 2 to 3%, a material having a high electric conductivity is used as an electrode material for wiring. There is a need.

Therefore, when the magnetoresistive effect type head as shown in FIGS. 5 and 6 is formed, it is necessary to process the array of the magnetoresistive effect elements and the wiring of the electrodes. Therefore, when the magnetic effect head shown in FIG. 6 is produced, the magnetoresistive effect material is once formed on the substrate, processed into an array, and then the electrode material is further formed, It was necessary to form an electrode pattern, which was a complicated fabrication process.

From the above problems, (a) a magnetoresistive head having a simple structure and high reliability is demanded. (B) Further, there is a demand for a mechanism capable of manufacturing the magnetoresistive head by a simple manufacturing process.
(C) Furthermore, using the magnetoresistive head,
There is a demand for providing a small and highly reliable reader capable of reading magnetic stripe information on a magnetic card or the like.

[0013]

[Means for Solving the Problems]

(1) Therefore, in the magnetoresistive head of the present invention, a thin film for electrodes (which is for applying electric power) is laminated on a substrate (for example, a nonmagnetic substrate made of glass or the like),
A magnetoresistive thin film is laminated on the electrode thin film, and the electrodes are arranged in an array on the magnetoresistive thin film. The above-mentioned problem (a) is solved by such a configuration.

(2) In another magnetoresistive head according to the present invention, an array electrode is arranged on a substrate, a magnetoresistive thin film is laminated on the array electrode, and the magnetoresistive effect is obtained. The thin film for electrodes is laminated on the thin film. The above-mentioned problem (a) is solved by such a configuration.

(3) Further, in the method of manufacturing a magnetoresistive head of the present invention, a step of forming a thin film for an electrode on a substrate by a sputtering method or a vapor deposition method, and a sputtering method or a method on the thin film for an electrode. A step of forming a magnetoresistive thin film by vapor deposition, a step of forming a thin film on the magnetoresistive thin film for forming array electrodes by sputtering or vapor deposition, and processing this thin film by photolithography. And a step of producing an array electrode. The above-mentioned problem (b) is solved by such a configuration.

(4) Furthermore, another method for manufacturing a magnetoresistive head according to the present invention is a step of forming a thin film for forming an array-like electrode on a substrate by a sputtering method or a vapor deposition method, and this thin film. To form an array electrode by photolithography, a step of forming a magnetoresistive thin film on the array electrode by a sputtering method or a vapor deposition method, and a sputtering method on the magnetoresistive thin film. Or a step of forming a thin film for electrodes by a vapor deposition method. The above-mentioned problem (b) is solved by such a configuration.

(5) Further, in the magnetic stripe information reading apparatus of the present invention, the magnetic stripe information of the magnetic recording medium is read by using the magnetoresistive head having the structure of (1) or (2). In the device, electric power is applied to the electrode thin film of the magnetoresistive head, and the leakage magnetic field from the magnetic stripe portion of the magnetic recording medium is detected by the magnetoresistive head. It is provided with a reading means for taking out the detection signal, processing the detection signal and reading it. With such a configuration, the above-mentioned problem (c) is solved.

[0018]

The structure of the magnetoresistive head according to the present invention is very simple, mainly because of the laminated structure of the magnetoresistive thin film and the electrode thin film on the substrate and the arrangement of the array electrodes. Is. Therefore, miniaturization becomes easy. Furthermore,
Since the structure is simple, the reliability can be improved.

Further, also in the manufacturing method, since the thin film is formed by a general sputtering method or vapor deposition method, it can be easily realized by using the conventional thin film forming technique. Furthermore, even in the production of the array-shaped electrode, since it is only processed and arranged on the electrode thin film or the substrate by using the photolithography method, this step also requires no development of a new technique, It can be easily manufactured.

It is considered that the use of the small magnetoresistive head having the above-mentioned configuration (1) or (2) facilitates miniaturization of the magnetic stripe information reading apparatus and improves the reading reliability.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. Therefore, in the magnetic stripe information reading apparatus of this embodiment, a magnetoresistive head having a structure in which a thin film for electrodes, a thin film for magnetoresistive effect, and electrodes arranged in an array are laminated on a substrate is used. It is configured to read the magnetic stripe information.

With this structure, it is intended to realize a magnetic stripe information reader having a magnetoresistive head which can be formed by a simple manufacturing process.

(Structure of the magnetoresistive head 20):
1 and 7 show a magnetoresistive head 2 of this embodiment.
It is explanatory drawing of 0. First, in FIG. 1, a magnetoresistive head 20 has a thin film 11 for electrodes laminated on a non-magnetic substrate 10 such as glass, and a thin magnetoresistive film 12 is further laminated on the thin film 11 for electrodes. . Furthermore, the electrodes 13a to 13e processed into an array are laminated on the magnetoresistive thin film 12.

The electrode thin film 11 is connected to a constant voltage power source line 18, and further array electrodes 13a to 13a.
e is connected to each of the detection ICs 17.

(Manufacturing Process of Magnetoresistive Head 20): FIG. 10 is a manufacturing process diagram of the magnetoresistive head 20 of one embodiment. In FIG. 10, first, the electrode thin film 11 is formed on the substrate 10 by the sputtering method (S1). Then, the magnetoresistive effect thin film 12 is formed on the electrode thin film 11 by the sputtering method (S2). Then, a thin film for forming an array electrode is formed on the magnetoresistive thin film 12 (S3). Then, this thin film is processed by a photolithography method to form and arrange the array electrodes 13 (S4).

(Outline of Read Operation): FIG. 7 is an explanatory diagram for explaining an outline of the read operation of the magnetic stripe information according to the embodiment. From the magnetic stripe portion 2 of the magnetic card or the like, a leakage magnetic field is generated at the magnetization reversal portion. Therefore, as shown in FIG. 7, the magnetoresistive head 20 is superposed on the magnetic stripe portion 2, and the leakage magnetic field is detected by the magnetoresistive effect. Here, the magnetoresistive effect is a phenomenon in which the electric resistance value changes depending on the presence or absence of a magnetic field. Therefore, as shown in FIG. 8, the electrode thin film 11 is connected to the constant voltage power supply line 18 and the arrayed electrodes 13 are connected. By connecting to the detection IC 17, the magnetic stripe information can be read.

(Evaluation of Read Operation): The result of evaluating the read operation of the magnetic stripe information with the above-mentioned configuration will be described below. In this evaluation, the substrate 10 using a glass substrate, the magnetoresistive material using _Ni 80 _{Fe 1 5} Co 5 alloy film produced by a sputtering method,
A Cu thin film was used as the electrode thin film 11.

Then, FIG. 9 shows the measurement results of the electric and magnetic characteristics of the magnetoresistive material (Ni ₈₀ Fe ₁₅ Co ₅ ) used in this evaluation by the DC 4-terminal method. The photolithography method was used for the arraying process of the electrodes 13. It was confirmed that magnetic recording was performed on the magnetic stripe portion of a commercially available magnetic card with the shortest magnetic domain width of about 50 μm, and this was detected by the magnetoresistive head 20 and it was possible to read.

(Effect of One Embodiment) According to the above one embodiment, in the magnetic stripe information reading apparatus such as a magnetic card, the electrode thin film 11 and the magnetoresistive thin film 12 are further formed on the substrate, and the array-shaped thin film. By including the magnetoresistive head 20 having a structure in which the electrode 13 disposed in the magnetic stripe is stacked, it is possible to read the magnetic stripe information depending on the presence or absence of the leakage magnetic field generated from the magnetic stripe portion 2. .

Further, since the structure of the magnetoresistive head is very simple, it is considered to have high reliability. Furthermore, the manufacturing process of the magnetoresistive head is also a simple manufacturing process.

(Other Embodiments): (1) FIG. 11 is a block diagram of a magnetoresistive head 30 of another embodiment. 11, electrodes 14 arranged in an array on a non-magnetic substrate 10 such as a glass substrate, a magnetoresistive effect thin film 15 and an electrode thin film 16 are laminated in this order, and the magnetic field shown in FIG. The stacking order is opposite to that of the film structure of the resistance effect head 20. Also in this case, the electrode thin film 16 is connected to the constant voltage power supply line 18, and the array-shaped electrodes 14 are connected to the detection IC 19.

((Manufacturing Process of Magnetoresistive Effect Head 30)): FIG. 13 is a manufacturing process diagram of the magnetoresistive effect head 30. In FIG. 13, first, the substrate 10
A thin film for forming an array-shaped electrode is formed on the substrate by a sputtering method (S10). Next, the thin film is processed into an array by photolithography and arranged on the electrodes 14 (S).
11). Next, the magnetoresistive thin film 15 is formed on the electrode 14 in the form of an array by the sputtering method (S12). Finally, the electrode thin film 16 is formed on the magnetoresistive thin film 15 by the sputtering method (S13).

The magnetoresistive head 3 having such a structure
Even with 0, a read operation similar to the read operation of the magnetic stripe information of the above-described embodiment can be realized. Moreover, the magnetoresistive head 30 can be manufactured by a simple manufacturing process.

(2) Further, although the sputtering method is used in the above-mentioned embodiment, the vapor deposition method may be used instead.

(3) Further, as the magnetoresistive material, a NiFeCo alloy film having another composition is also preferable. In addition, NiCo,
Other magnetic alloy films such as NiFe, and further Co / C
Artificial lattice magnetic materials exhibiting a giant magnetoresistive effect such as u, Fe / Cr, Co / Ag are also preferable.

[0036]

As described above, according to the magnetoresistive head of the present invention, it is possible to reduce the size and improve the reliability. Further, according to the method of manufacturing the magnetoresistive head of the present invention, it is possible to manufacture by a very simple process. Furthermore, according to the magnetic stripe information reading apparatus using the magnetoresistive head of the present invention, it is possible to easily downsize the apparatus and improve the reading reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a magnetoresistive head according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a magnetic stripe information reading apparatus using a conventional electromagnetic induction type magnetic head.

FIG. 3 is an explanatory diagram of a magnetic stripe information reading apparatus using a conventional magnetoresistive head.

FIG. 4 is an explanatory diagram of reading magnetic stripe information in a conventional example.

FIG. 5 is an explanatory diagram of a conventional magnetoresistive head and a detection IC.

FIG. 6 is a configuration diagram of a conventional magnetoresistive head.

FIG. 7 is a conceptual diagram of reading magnetic stripe information according to an embodiment.

FIG. 8 is a configuration diagram of a magnetic stripe information reading device according to an embodiment.

FIG. 9 is a magnetoresistive material (NiFeCo) of one example.
3 is an electric / magnetic characteristic diagram of FIG.

FIG. 10 is a manufacturing process diagram of the magnetoresistive head of one embodiment.

FIG. 11 is a configuration diagram of a magnetoresistive effect head according to another embodiment.

FIG. 12 is a configuration diagram of a magnetic stripe information reading device according to another embodiment.

FIG. 13 is a manufacturing process diagram of a magnetoresistive head according to another embodiment.

[Explanation of symbols]

10 ... Substrate, 11 ... Electrode thin film, 12 ... Magnetoresistive thin film, 13 ... Array electrode, 20 ... Magnetoresistive head.

Claims (5)

[Claims] 1. A thin film for electrodes is laminated on a substrate, a magnetoresistive thin film is laminated on the thin film for electrodes, and electrodes are arranged in an array on the thin magnetoresistive film. Characteristic magnetoresistive head. 2. An array electrode is arranged on a substrate, a magnetoresistive effect thin film is laminated on the arrayed electrode, and an electrode thin film is laminated on the magnetoresistive effect thin film. And a magnetoresistive head. 3. A step of forming a thin film for electrodes on a substrate by a sputtering method or an evaporation method; a step of forming a magnetoresistive thin film on the thin film for electrodes by a sputtering method or an evaporation method; It is characterized by comprising a step of forming a thin film for forming an array-like electrode on a thin film by a sputtering method or a vapor deposition method, and a step of processing the thin film by a photolithography method to form an array-like electrode. A method of manufacturing a magnetoresistive head. 4. A step of forming a thin film for forming an array electrode on a substrate by a sputtering method or a vapor deposition method, a step of processing the thin film by a photolithography method to form an array electrode, and the array. It is characterized by comprising a step of forming a magnetoresistive effect thin film on a flat electrode by a sputtering method or an evaporation method, and a step of forming an electrode thin film on the magnetoresistive effect thin film by a sputtering method or an evaporation method. A method of manufacturing a magnetoresistive head. 5. A magnetic stripe information reading device for reading magnetic stripe information of a magnetic recording medium using the magnetoresistive head according to claim 1 or 2, wherein the thin film for electrodes of the magnetoresistive head. Power is applied to the magnetic recording medium, the leakage magnetic field from the magnetic stripe portion of the magnetic recording medium is detected by the magnetoresistive head, the detection signal is extracted from the magnetoresistive head array electrode, and the detected signal is processed. An apparatus for reading magnetic stripe information, characterized by comprising reading means for reading.