JPH029037A - Magneto-optical card recording medium - Google Patents

Abstract

PURPOSE:To simplify a recording process and to speed up recording by adding conductive patterns to the magneto-optical card recording medium, generating a bias magnetic field by the current passed to the conductor patterns to control the recording magnetization direction, thereby allowing direct overwriting. CONSTITUTION:Magnetic field generating parts M(2i-1), M(2i) are selected as desired two terminals corresponding to an input signal from an input signal terminal 16 by a selecting circuit 3 from n-pieces of the folded conductor patterns 6 of the two terminals. Current is passed between these two terminals via a current supplying terminal 17. The magnetic field shown by broken lines is generated around the generating parts M(2i-1), M(2i) connected in a common juncture Ci in this way. A perpendicular bias magnetic field 13 can be impressed to the recording layer 12 formed between these generating parts M(2i-1), M(2i). Namely, the recording magnetization direction is determined by the direction of the bias magnetic field and, therefore, overwriting of the recording magnetization is executed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a magneto-optical card recording medium, in particular, a magnetic film having an axis of easy magnetization perpendicular to the film surface as a recording layer, and a light beam such as a laser The present invention relates to a magneto-optical card recording medium in which information can be recorded by creating reversed magnetic domains in the irradiated area and read out using the magneto-optic effect.

[Conventional technology]

Generally, optical memory is positioned as one type of large-capacity file memory. Among them, magneto-optical memory has attracted attention because it has the advantage that recorded information can be rewritten, and in particular, its application to disks is being actively researched in various places. As the optical recording medium, Tb, Gd
, Dy, Ha, etc., and transition metals, such as Fe, Co, Ni, etc., are combined to create an amorphous magnetic thin film that has high recording sensitivity, no grain boundary noise, and magnetic properties perpendicular to the film surface. It is considered the most promising because it has advantages such as the ability to easily produce films with anisotropy.

Information is recorded and erased on such an optical recording medium as follows.

Recording is performed by irradiating a unidirectionally magnetized optical recording medium with a laser beam to raise the medium temperature above the Curie temperature Tc or the compensation temperature 7'coml), and using an externally applied magnetic field and a demagnetizing field of the optical recording medium. This is done by forming reversed magnetic domains.

Erasing is performed by applying an external magnetic field with a polarity opposite to that of the recording layer and uniformly irradiating the optical recording medium with a laser beam at the same intensity as during recording, so-called -batch erasing. This results in
The magnetization state of the recording medium returns to the initial state before recording.

[Problem to be solved by the invention]

As described above, the application of conventional magneto-optical recording media is mainly intended for disk media, and almost no application to card media has been reported.

Furthermore, when recording information on a conventional magneto-optical recording medium, an external magnetic field application means is required in addition to the optical system that generates the laser beam, so the configuration of the magneto-optical recording/reproducing device is , tended to be complex. Furthermore, since the external magnetic field strength requires an order of several hundred oersteds, it is difficult to switch this at high speed using conventional magnetic field applying means such as air-core Koinope electromagnets and permanent magnets. Therefore, for erasing, the above-mentioned batch erasing method has been used, and for recording, a method has been used in which laser light power is modulated at high speed in a constant magnetic field.

Therefore, recording information requires an erasure process.
This has the drawback that the recording/reproducing operation becomes complicated and speeding up is limited.

[Means to solve the problem]

The magneto-optical card recording medium of the present invention is formed of a conductor on a base, and has a conductor pattern formed of a plurality of magnetic field generating parts having a certain interval and connected at one end by a common connection part,
A recording layer made of an amorphous magnetic alloy film having magnetic anisotropy in the direction perpendicular to the film surface and a protective layer made of a dielectric are formed thereon in this order via an insulating layer made of a dielectric, and further, It is configured to include a selection circuit that selects desired two adjacent terminals from among the plurality of magnetic field generation units.

Further, in the magneto-optical card recording medium of the present invention, the conductive pattern is composed of a plurality of folded two-terminal patterns having a blind-like pattern.

[Effect]

In the case of a folded conductive pattern, a desired two terminal is selected from among a plurality of folded two terminal patterns, and a current is passed between the two terminals to form a recording layer between the patterns. A bias magnetic field can be applied from the perpendicular direction. The direction of applying this bias magnetic field is
Switching can be done easily by switching the current direction. Furthermore, the linear groove formed by this two-terminal pattern also serves as a guide track for the optical head. Therefore, by irradiating the recording layer with a laser beam while moving it in parallel along the guide track, and at the same time passing a current corresponding to the recording signal between the two terminals, the recording layer is exposed to the signal. A corresponding magnetization state can be realized.

In the case of a blind-shaped conductive pattern, a desired adjacent two-terminal pattern is selected from blind-shaped patterns having a certain interval, one of which is made up of a plurality of terminals and the other of which is commonly connected, and the two terminals are connected together. By passing a current between the patterns, a bias magnetic field can be applied in the perpendicular direction to the recording layer formed between the patterns. The bias magnetic field application direction can be easily switched by switching the current direction. Further, the linear groove formed by this conductor pattern also serves as a guide track for the optical head. Therefore, by irradiating the recording layer with a laser beam while moving it in parallel along the guide track, and at the same time passing a current corresponding to the recording signal between the two terminals, the recording layer receives the signal corresponding to the signal. A magnetized state can be achieved.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a plan view showing a first embodiment of the present invention, FIG. 2 is a partial perspective view of the magneto-optical medium shown in FIG. 1, and FIG. 3 is a partial cross-sectional view of the magneto-optical medium shown in FIG. 1. , Fig. 4(a), (b
) is a perspective view showing a method of creating the conductor pattern shown in FIGS. 1 to 3, and FIG. 5 is an operation explanatory diagram for explaining the operation of the embodiment shown in FIG. 1.

The magneto-optical card recording medium shown in FIG. The selection circuit 3 selectively supplies current from the current supply terminal 17.

The substrate 1 is made of polycarbonate or PMMA with a thickness of 1.2 mm.
A card-shaped plastic board (55 m long) consisting of
5i with a thickness of 500 people on this board 1.
Through an insulating pattern 4 made of an sNa film (silicon nitride film) and an adhesion pattern 5 made of a Ti film (titanium film) with a thickness of 100, Au (gold) or AA with a height of about 3000 and a width of about 4000 is formed. A folded two-terminal conductive pattern 6 made of a conductive material such as (aluminum) is formed.

This conductor pattern 6 includes magnetic field generating portions M1, M2, . ~M(2
n) and common connection portions CI, C2, to Cn.

5ixN4 with a thickness of 500 on this conductor pattern 6
A recording layer 8 made of an amorphous magnetic alloy film having magnetic anisotropy in the direction perpendicular to the film surface is formed through an insulating layer 7 made of a film.
3000mm thick TbFeCo alloy film (Tb a2z
F e o, v*c o aos), and a Si 3N4 film with a thickness of 1000 nm is further formed as a protective layer 9.

Each layer is formed by magnetron sputtering.

First, a folded two-terminal conductor pattern 6 made of a conductor such as A u 'e' A 1 is formed as follows.

As shown in FIG. 4(a), an insulating layer 4' consisting of a 5isNt film with a thickness of 500 nm and a Ti film with a thickness of 100 nm are formed on the substrate 1.
After sputtering an adhesion layer 5' consisting of a film, and a conductor layer 6' of 3000 mm thick Au,
Resist putter 7 (AZ) with width 5000 and length 30mm
1350J) are formed at a pitch of 1.6 μm.

Then, using Ar (argon), the gas pressure was increased to 2.
Ion mill for 4 minutes at 6 x 10-''Pa.

Furthermore, by peeling off the remaining resist using oxygen plasma, a folded two-terminal conductor pattern 6 of Au is formed with a height of 3000 mm, as shown in FIG. 4(b).
It is formed with a width of 4,000 people and a pitch of 1.6 μm. The TbFeCo alloy film forming the recording layer 8 has a FeCo target,
Using a composite target with a Tb piece placed on top of the target, it was created in an Ar gas atmosphere at a power density of 4 W/Ci and a sputtering gas pressure of 3.5 x 10-'Pa. The 5ixN4 film forming the insulating layer 7 and the protective layer 9 was formed using a Si target.
By reactive sputtering using a mixed gas of IR and N2 (50% N2) as the sputtering gas, the power density is 8W/co!
, prepared with Shutta gas EE2.5XlO-'Pa.

Next, the recording operation of the magneto-optical card recording medium shown in FIG. 1 using the magneto-optical recording medium shown in FIGS. 7 and 3 will be explained with reference to the drawings.

From among the n folded two-terminal conductor patterns 6 shown in FIG. 1, the selection circuit 3 selects a magnetic field generating portion M (
21-1), M(2i) is selected, and as shown in FIG. 5, when a current is passed between these two terminals via the current supply terminal 17, a folded magnetic field connected at the common connection part Ci is generated. A magnetic field indicated by a broken line 11 is generated around the portions M(2i-1) and M(2i). In other words, this magnetic field generating part M (2i1
), M (2i), the recording layer 12 formed between
A vertical bias magnetic field 13 can be applied. The direction and magnitude of this bias magnetic field can be easily selected by changing the current direction 18 and magnitude of the current flowing between the two terminals. Therefore, as shown in FIG. 5, while moving the laser beam 14 relatively parallel in the longitudinal direction using the folded pattern as a guide track, the recording layer 12, 20 between the patterns is moved.
by sequentially irradiating the recording layer 12.20 to raise the temperature of the recording layer 12.20 above the Curie temperature Tc (approximately 220° C.), and at the same time, by switching the current flowing between the two terminals in accordance with the timing of magnetization, During the cooling process of the recording layer 12.20, a desired magnetization state corresponding to the recording signal can be realized in the recording layer 12.20.

In this way, in the recording operation using the magneto-optical recording medium 2,
Since the recorded magnetization direction is determined by the direction of the bias magnetic field, not by the initial magnetization direction of the recording layer, it is possible to overwrite, ie, override, the recorded magnetization as in normal magnetic recording. Furthermore, since the inductance of the two-terminal pattern can be on the order of several microhenries, high-speed current switching on the order of megahertz is also possible.

Here, the current value is appropriately selected in the range of several tens to several hundred mA depending on the film composition of the recording layer. The height, pitch, length, and other shapes of the conductor pattern are not limited to those described above, but are appropriately selected depending on the recording density of the desired optical recording medium and the magnitude of the bias magnetic field. The height of the conductor pattern is several thousand holes, and the pitch is:
Desirably, the thickness is on the order of several μm. In addition to 5i31'L, the dielectric materials used as the insulating layer and the protective layer include Al;
N.

A material formed of SiO, SiO, etc. with a thickness of several hundred to several thousand holes is used. Further, the deposit layer 5', that is, the deposit pattern 5, is not necessarily necessary if the adhesion between the insulating layer 4', that is, the insulating pattern 4, and the conductive layer 6', that is, the conductive pattern 6 is sufficiently strong.

6 is a plan view showing a second embodiment of the present invention, FIG. 7 is a partial perspective view of the magneto-optical recording medium shown in FIG. 6, and FIG. 8 is a partial perspective view of the magneto-optical recording medium shown in FIG. 7. Cross-sectional view, Figure 9(a)
, (b) is a perspective view showing the method of creating the conductor patterns shown in FIGS. 6 to 8, and FIG. 1O is an operation explanatory diagram for explaining the operation of the embodiment shown in FIG. 6.

The magneto-optical card recording medium shown in FIG. 6 includes a magneto-optical medium 21 including a conductive pattern 23 on a card-like base 1;
The selection circuit 22 is configured to include a selection circuit 22.

As shown in FIGS. 7 and 8, the magneto-optical recording medium 21 includes an insulating pattern 24, an adhesion pattern 25, a conductor pattern 23, an insulating layer 7, a recording layer 8, and a protective layer 9. .

The conductor pattern 23 includes magnetic field generating portions Ml, M2 . ~M (
21-1), M (2i), ~M (2n) and the magnetic field generating portions Ml, M2. . . . and a common connection portion CT that commonly connects one end of . In other words, the conductor pattern
723 C-Zetsu 1 & Pattern 24 forms a star like the adhered putter 725.

The selection circuit 22 includes magnetic field generating units Ml, M2 . Select two adjacent terminals among ~ according to the input signal supplied from the input signal terminal 16, and select the current supply terminal 1 to generate a magnetic field.
7 is supplied with current.

The substrate 1 is made of polycarbonate or PM with a thickness of 1.2 mm.
A card-shaped plastic board made of MA etc. (vertical 5
5 mm (width 85 mm) and 500 mm thick on this board 1.
Insulating layer 4 made of 1gN4 film and T of 100mm thick
Through an adhesion layer 5 made of an i-film, conductors such as Au and An having a height of about 3,000 and a width of about 4,000 are connected to the magnetic field generating portions M1, M2, etc. at a constant interval of about 1.6 μm. ~ were placed together. ffi! A conductor pattern 23 having a shape is formed. On top of this, a recording layer 8 made of an amorphous magnetic alloy film having magnetic anisotropy in the direction perpendicular to the film surface is formed, with a thickness of 30 nm, through an insulating layer 7 made of a 5isN4 film with a thickness of 500 nm.
00 TbFeCo alloy film (T b a, u Fe
o, tzCOn, o*), and a Si3N4 film with a thickness of 1000 nm is further formed as a protective layer 9.

Each layer is formed by magnetron bathing. First, the mud-like conductor pattern 23 made of Au, F1, etc.
It is formed as follows. As shown in FIG. 9(a), on the substrate l, there is an insulating layer 4' made of a 5II N4 film with a thickness of 500, an adhesion layer 5' made of a Ti film with a thickness of 100, and an Au layer with a thickness of 3000. After sputtering the conductive layer 6' in this order, a mud-like resist pattern (2500 mm thick, 5500 mm wide, 30 plates long, and 1.6 μm pitch) is formed.
AZ1350J is used) 10 is formed.

After that, using Ar, the gas pressure was 2.6×10-'Pa.
Perform ion milling for 4 minutes. Furthermore, by peeling off the remaining resist using oxygen plasma, a muddy Au conductor pattern 23 is formed, as shown in FIG. 9(b).
However, the height is 3000 people, the width is 4000 people, and the pitch is 1.6 μm.
is formed. The TbFeCo alloy film forming the recording layer 8 is
Using a composite target with a Tb piece placed on a FeCo target, the power density was 4 W/cni in an Ar gas atmosphere.
, with a sputtering gas pressure of 3.5×10'Pa. The Si3N4 film forming the insulating layer 7 and the protective layer 9 is formed using a Si target and a mixed gas of Ar and N2 (50% N2).
was used as sputtering gas, power density 8 W/cd, sputtering gas [2.5X10''P
It is made in a.

Next, the recording operation of the magneto-optical card recording medium shown in FIG. 6 will be explained using the drawings.

2n magnetic field generating portions Ml, M2 . ~． From the terminals of M(2n), the selection circuit 22 selects two desired adjacent terminals M(2i-1) and M(2i) according to the input signal from the input signal terminal 16.
When a current is passed between these two terminals via the current supply terminal 17 as shown in FIG.
It produces a magnetic field shown as . That is, the bias magnetic field 13 can be applied in the perpendicular direction to the recording layer portions 12, 19, 20 formed between these patterns.

The direction and magnitude of this bias magnetic field are:
It can be easily selected by changing the direction and magnitude of the current flowing between the two terminals.

Therefore, as shown in FIG. 10, the laser beam 14 is
The magnetic field generating portions Ml, M2 . of the mud-like conductor pattern 23 . ~
are used as guide tracks, and the magnetic field generating parts Ml, M2 . By irradiating the recording layers 12, 19° 20 located between .
The temperature of 19.20℃ is higher than the Curie temperature Tc (approximately 220℃
), and at the same time, by switching the current flowing between the two terminals in accordance with the timing of magnetization, the recording layer 1
2, 19, and 20, a desired magnetization state corresponding to the recording signal can be realized.

In this way, in a recording operation using a magneto-optical recording medium, the direction of recorded magnetization is determined by the direction of the bias magnetic field, not by the initial magnetization direction of the recording layer. can be written, or overridden. Furthermore, since the inductance of the two-terminal pattern can be on the order of several microhenries, high-speed current switching on the order of megahertz is also possible.

Furthermore, when using the mud-like conductor pattern 23, all the recording layers 12, 19, 20 can be used, which is more efficient than the folded pattern.

Here, the current value is appropriately selected in the range of several tens to several hundred mA depending on the film composition of the recording layer. The height, pitch, length, and other shapes of the conductor pattern are not limited to those described above, but are appropriately selected depending on the recording density of the desired recording medium and the magnitude of the bias magnetic field. The height of the conductor pattern is several thousand people, and the pitch is:
Desirably, the thickness is on the order of several μm. In addition to Si3N4, the dielectric materials used as the insulating layer and the protective layer include AuN,
A material formed of S jo2°Si○ or the like to a thickness of several hundred to several thousand layers is used.

Further, the above-mentioned adhesion layer 5' includes an insulating layer 4' and a conductive layer 6'.
If the adhesion force between the insulating pattern 4 and the conductive pattern 6 is sufficiently strong, the insulating pattern 4 and the conductive pattern 6 will be sufficiently adhered even without the adhesion pattern 5, so this is not necessarily necessary.

〔Effect of the invention〕

By adding a conductor pattern to the magneto-optical card recording medium of the present invention, a bias magnetic field can be generated by the current flowing through the conductor pattern to control the direction of recording magnetization, so direct override can be achieved, so the recording process can be controlled. This has the effect of being simpler and faster.

[Brief explanation of the drawing]

1 is a plan view showing a first embodiment of the present invention, FIG. 2 is a partial perspective view of the magneto-optical recording medium shown in FIG. 1, and FIG. 3 is a partial perspective view of the magneto-optical recording medium shown in FIG. 2. Cross-sectional view, Fig. 4(a),
(b) is a perspective view showing the method for creating the conductive pattern shown in FIGS. 1 to 3, FIG. 5 is an operation explanatory diagram for explaining the operation of the embodiment shown in FIG. 1, and FIG. 7 is a partial perspective view of the magneto-optical recording medium shown in FIG. 6; FIG. 8 is a partial sectional view of the magneto-optical recording medium shown in FIG. 7; Figures 9 (a) and (b) are from Figures 6 to 8.
A perspective view illustrating the method for creating the conductor pattern shown in the figure, No. 10.
This figure is an operation explanatory diagram for explaining the operation of the embodiment shown in FIG. 6. ■...Base, 2,21. ...Magneto-optical recording medium, 3.22...Selection circuit, 4,24...
...Insulating pattern, 5, 25... Adhesion pattern, 4', 7... Insulating layer, 5'...
Adhesive layer, 6, 23... Conductor pattern, 6'.
...Conductor layer, 8.12.19.20...
・Recording layer, 9...protective layer, 10...resist pattern, 11...magnetic field, 13...
...Bias magnetic field, 14...Laser beam, 1
5... Lens, 16... Input signal terminal, 17... Current supply terminal, 18... Current direction, Ml, M2. ~． M (2n) ---Magnetic field generation section, C1, C2, ~Cn, CT... Common connection section. Agent Patent Attorney Susumu Uchihara ＼ ＼ 2nd 4th αυ (b) M7 side′! A9TiJ

Claims (1)

[Claims] 1. Consisting of a base body and one or more common connection parts that are provided on the base body and commonly connect one end of at least two of the magnetic field generation parts adjacent to the plurality of magnetic field generation parts. A conductor pattern, an insulating layer made of a dielectric material provided on the conductor pattern, and a magnetic anisotropy in a direction perpendicular to a film surface provided at least between the adjacent magnetic field generating parts. a recording layer made of an amorphous magnetic alloy film, a protective layer made of a dielectric material for protecting the recording layer, and a pair of adjacent said recording layers for energizing to generate a magnetic field for recording in the recording layer. 1. A magneto-optical card recording medium, comprising a selection circuit for selecting the other end of the magnetic field generating section. 2. A conductive pattern consisting of a base body and a plurality of pairs of common connection parts that are provided on the base body and commonly connect ends of a pair of adjacent magnetic field generation parts in a folded manner; an amorphous magnetic alloy film having magnetic anisotropy in a direction perpendicular to the film surface provided at least between an insulating layer made of a dielectric material provided on the conductive pattern and the adjacent magnetic field generating portions; a protective layer made of a dielectric material to protect the recording layer; and the other end of a pair of adjacent magnetic field generating parts for applying current to generate a magnetic field for recording in the recording layer. A magneto-optical card recording medium comprising a selection circuit for selecting. 3. A conductive pattern comprising a base body, a common connection part provided on the base body and commonly connecting a plurality of magnetic field generating parts and one end of the magnetic field generating parts in a blind shape, and a conductive pattern on the conductive pattern. an insulating layer made of a dielectric material, a recording layer made of an amorphous magnetic alloy film having magnetic anisotropy in the direction perpendicular to the film surface and provided at least between the adjacent magnetic field generating parts; a protective layer for protecting the recording layer; and a selection circuit for selecting the other end of the pair of adjacent magnetic field generating parts for energizing to generate a magnetic field for recording in the recording layer. A magneto-optical card recording medium comprising: