JP4559253B2 - Flexible substrate manufacturing method and flexible magneto-optical recording medium - Google Patents

Description

  The present invention relates to a method for manufacturing a flexible substrate for use in, for example, a flexible magneto-optical disk, and a flexible magneto-optical recording medium.

  A magneto-optical recording medium is known as one form of optical media from which information is optically read. A magneto-optical recording medium is a rewritable medium that is thermomagnetically recorded and reproduced using the magneto-optical effect. The magneto-optical recording medium is described in, for example, the following Patent Documents 1 and 2.

Japanese Patent Application Laid-Open No. 6-290496 JP 2001-56777 A

  FIG. 6 shows a magneto-optical disk X2 which is an example of a conventional magneto-optical recording medium. The magneto-optical disk X2 has a laminated structure including a substrate 61, a recording magnetic part 62, a heat conductive layer 63, dielectric layers 64 and 65, and a protective film 66, and is a front-illuminated magneto-optical disk. It is configured.

  The substrate 61 is a part for ensuring the rigidity of the magneto-optical disk X2, and has a thickness of about 1 mm. The substrate 61 is made of a resin material, and a pregroove 61a is formed on the surface of the recording magnetic portion 62 side. Based on the pregroove 61a, the land groove shape in the magneto-optical disk X2 is realized. The recording magnetic unit 62 has a magnetic structure capable of performing two functions of thermomagnetic recording and reproduction utilizing the magneto-optical effect, and is composed of one or more magnetic films according to the reproduction method ( Including a recording layer in contact with the dielectric layer 64). The magnetic film is a rare earth-transition metal amorphous alloy perpendicular magnetization film. The heat conductive layer 63 is a part for efficiently transmitting the heat generated in the recording magnetic part 62 and the like during laser irradiation to the substrate 61 side, and is made of a high heat conductive material. The dielectric layers 64 and 65 are parts for avoiding an unreasonable magnetic influence or chemical influence from the outside on the recording magnetic part 62. The protective film 66 is a part for protecting the recording magnetic part 62 from dust, and is made of a light transmissive resin material.

  In manufacturing the magneto-optical disk X2 having such a configuration, first, as shown in FIG. 7A, a predetermined resin material is obtained by an injection molding method using a nickel stamper 71 as a part of a mold. From this, the substrate 61 is produced. The nickel stamper 71 has a predetermined convex pattern 71a on its surface, and a pregroove 61a is formed corresponding to the convex pattern 71a. Next, as shown in FIG. 7B, a heat conductive layer 63, a dielectric layer 64, a recording magnetic part 62, and a dielectric layer 65 are sequentially formed on the substrate 61 by sputtering. Thereafter, as shown in FIG. 7C, a protective film 66 is formed on the dielectric layer 65 by spin coating.

  When recording information on the magneto-optical disk X2, for example, the recording laser is irradiated as a continuous pulse signal from the protective film 66 side toward the recording magnetic part 62 while the disk is rotated. While the recording magnetic unit 62 is heated locally and sequentially, a recording magnetic field modulated in a predetermined manner is applied to the temperature rising portion by the magnetic recording head. Thereby, in the recording magnetic part 62 or the recording layer included therein, a plurality of magnetic domains (recording marks) whose magnetization directions are sequentially reversed are formed continuously in the circumferential direction or the track extending direction of the magneto-optical disk X2. In this manner, predetermined information or signals are recorded as changes in the magnetization direction in the recording magnetic part 62 or the recording layer included therein.

  As the amount of information processing in computer systems increases, a higher recording density is required for recording media such as magneto-optical discs. In the technical field of magneto-optical discs, the overall thickness of magneto-optical discs is set to be small. Therefore, there is a demand for increasing the volume recording density of the medium. In order to meet such a demand, it can be considered that the above-described magneto-optical disk X2 is constructed as a flexible magneto-optical disk by manufacturing the substrate 61 as a thin flexible substrate. The technology relating to the flexible disk medium is described in, for example, the following Patent Documents 3 and 4.

JP 2004-134019 A JP 2004-139654 A

  However, with the injection molding method described above with reference to FIG. 7A, it is difficult to produce a substrate 61 having a pre-groove 61a on the surface to a sufficient extent (for example, about 100 μm). The narrower the cavity in the mold corresponding to the thickness of the substrate 61 to be formed, the more difficult it is for the resin material for substrate formation to flow in the cavity and properly fill the cavity. Because it becomes. Therefore, according to the conventional method described above with reference to FIG. 7, it is difficult to manufacture the magneto-optical disk X2 as a flexible magneto-optical disk that is sufficiently thinned.

  The present invention has been conceived under the circumstances as described above, and is a flexible substrate manufacturing method suitable for manufacturing a sufficiently thin flexible substrate, and suitable for achieving a high volume recording density. Another object of the present invention is to provide a flexible magneto-optical recording medium.

  According to a first aspect of the invention, a method for manufacturing a flexible substrate for flexible media applications is provided. The method is interposed between a first substrate having a first uneven surface, a second substrate having a second uneven surface facing the first uneven surface of the first substrate, and the first and second substrates. A spreading step for spreading the curable resin material between the first and second substrates by rotating the laminate including the curable resin material, and curing for curing the spread curable resin material. Process.

  In the spreading step of the method, the first and second substrates and the laminate including the curable resin material between the substrates are rotated to utilize the centrifugal force acting on the curable resin material, and the first and second substrates are rotated. Between the second substrates, the curable resin material can be spread thinly along the uneven surfaces (having predetermined unevenness) of both substrates. By adjusting the rotational speed of the laminate (that is, by adjusting the centrifugal force acting on the curable resin material), it is possible to adjust the degree of spread or thinness of the curable resin material. And in a hardening process, the flexible substrate which has the uneven | corrugated shape corresponding to the uneven | corrugated shape of the uneven | corrugated surface of both board | substrates can be formed by hardening | curing curable resin material. In the case of adopting an ultraviolet curable, thermosetting, or catalyst curable resin material as the curable resin material, the curable resin material can be cured by performing ultraviolet irradiation, heating, or addition of a catalyst, respectively. .

  Therefore, according to this method, the first and second uneven surfaces of the first and second substrates are set to have a convex pattern corresponding to a predetermined pregroove pattern to be formed on the surface of the flexible substrate. A sufficiently thin flexible substrate having pregrooves on both sides can be appropriately manufactured.

  According to a second aspect of the present invention, a method for manufacturing a flexible substrate for flexible media applications is provided. The method includes a first substrate having a first uneven surface, a second substrate having a second uneven surface facing the first uneven surface of the first substrate, and first and second substrates having openings. And rotating the laminated body including the reinforcing hub interposed between the first and second substrates around the reinforcing hub, thereby rotating the laminated body including the reinforcing hub interposed between the first and second substrates. A spreading process for spreading the curable resin material in between, and a curing process for curing the spread curable resin material. The reinforcing hub in the present invention has a strength against the mechanical contact at a portion where the drive mechanism for rotating the flexible medium mechanically contacts the flexible medium at the time of recording or reproducing information on the flexible medium. It is a member for ensuring, for example, consisting of metal.

  In the spreading step of this method, by rotating the laminate including the first and second substrates and the reinforcing hub between the two substrates and the curable resin material, utilizing the centrifugal force acting on the curable resin material, The curable resin material can be spread thinly between the first and second substrates and around the reinforcing hub along the uneven surfaces (having predetermined unevenness) of both substrates. As described above with respect to the first aspect, it is possible to adjust the extent or thinness of the curable resin material in the spreading process. In the curing step, a curable resin material is cured to form a flexible substrate in which a reinforcing hub having an uneven shape corresponding to the uneven shape of the uneven surface of both substrates is integrated on both sides and having an opening. Can be formed. About the hardening method of curable resin material, it is the same as that mentioned above regarding the 1st side.

  Therefore, according to this method, the first and second uneven surfaces of the first and second substrates are set to have a convex pattern corresponding to a predetermined pregroove pattern to be formed on the surface of the flexible substrate. It is possible to appropriately manufacture a flexible substrate having pregrooves on both sides and sufficiently thin and having a reinforcing hub having an opening integrated at a predetermined location.

  According to a third aspect of the present invention, a flexible magneto-optical recording medium is provided. The magneto-optical recording medium includes a first recording magnetic unit, a second recording magnetic unit, and a flexible substrate positioned between the first and second recording magnetic units. The flexible substrate includes a first substrate having a first uneven surface, a second substrate having a second uneven surface facing the first uneven surface of the first substrate, and the first and second substrates. And a step of spreading the curable resin material between the first and second substrates by rotating the laminate including the curable resin material to be cured, and a step of curing the curable resin material. It has been done. In the flexible magneto-optical recording medium of the present invention, information recording and information reproduction are performed while surface blurring is suppressed by a so-called Bernoulli effect.

  The flexible magneto-optical recording medium includes a flexible substrate obtained by the method of the first aspect of the present invention. As described above, this substrate can be formed sufficiently thin with pregrooves on both sides. This flexible magneto-optical recording medium having such a thin flexible substrate as a base material and having recording magnetic portions on both sides is suitable for achieving a high volume recording density by sufficiently reducing the thickness.

  According to a fourth aspect of the present invention, a flexible magneto-optical recording medium is provided. The magneto-optical recording medium includes a first recording magnetic unit, a second recording magnetic unit, and a flexible substrate positioned between the first and second recording magnetic units. The flexible substrate includes a first substrate having a first uneven surface, a second substrate having a second uneven surface facing the first uneven surface of the first substrate, and first and second openings. The first and second substrates are rotated by rotating a laminate including a reinforcing hub interposed between the substrates and a curable resin material interposed between the first and second substrates around the reinforcing hub. It is manufactured through a step of spreading the curable resin material between and a step of curing the curable resin material.

  The flexible magneto-optical recording medium includes a flexible substrate obtained by the method of the second aspect of the present invention. As described above, this substrate can be formed sufficiently thin with pregrooves on both sides. This flexible magneto-optical recording medium having such a thin flexible substrate as a base material and having recording magnetic portions on both sides is suitable for achieving a high volume recording density by sufficiently reducing the thickness. In addition, the flexible substrate of the flexible magneto-optical recording medium is formed by integrating the curable resin material portion and the reinforcing hub as described above. Such a configuration secures the strength of the portion where the drive mechanism for rotating the flexible magneto-optical recording medium mechanically contacts the flexible magneto-optical recording medium, thereby deforming the flexible magneto-optical recording medium. It is suitable for suppressing the above.

  According to a fifth aspect of the present invention, a flexible magneto-optical recording medium is provided. The magneto-optical recording medium has a first pre-groove surface and a main portion having a first pre-groove surface opposite to the first pre-groove surface and having a first opening, and a main opening at the first opening. A flexible substrate having a reinforcing hub provided within the thickness of the portion and having a second opening, a first recording magnetic portion on the first pregroove surface side, and a second recording magnetism on the second pregroove surface side A section. The first and second pregroove surfaces are surfaces on which pregrooves are formed.

  The flexible substrate of the flexible magneto-optical recording medium can be manufactured by the method of the second aspect described above. As described above, this substrate has pregrooves on both sides, and can be formed sufficiently thin by providing a reinforcing hub within the thickness of the main portion (curable resin material portion). This flexible magneto-optical recording medium having such a thin flexible substrate as a base material and having recording magnetic portions on both sides is suitable for achieving a high volume recording density by sufficiently reducing the thickness. In addition, the flexible substrate of the flexible magneto-optical recording medium is formed by integrating the curable resin material portion and the reinforcing hub as described above. Such a configuration secures the strength of the portion where the drive mechanism for rotating the flexible magneto-optical recording medium mechanically contacts the flexible magneto-optical recording medium, thereby deforming the flexible magneto-optical recording medium. It is suitable for suppressing the above.

  FIG. 1 is a partial sectional view of a magneto-optical disk X1 according to the present invention. The magneto-optical disk X1 includes a flexible substrate 10, two recording magnetic parts 21, two heat conducting layers 22, two dielectric layers 23, two dielectric layers 24, and two protective films 25. And a flexible magneto-optical disk having recording surfaces (configured by the recording magnetic unit 21) on both sides.

  As shown in FIG. 2, the flexible substrate 10 includes a main portion 11 and a reinforcing hub 12 (not shown in FIG. 1). The main portion 11 has an opening 11a at the center thereof, and has a thickness of, for example, 30 to 100 μm and is flexible. The stacked structure from the heat conductive layer 22 to the protective film 25 shown in FIG. 1 is provided on the main portion 11. A pregroove 11 b having a spiral or concentric pattern shape is formed on the surface of the main portion 11. Based on the pregroove 11b, the land groove shape in the magneto-optical disk X1 is realized. Moreover, the main part 11 consists of ultraviolet curable resin in this embodiment. In the present invention, a thermosetting resin or a catalyst curable resin may be employed as the constituent material of the main portion 11 instead of the ultraviolet curable resin.

  The reinforcing hub 12 of the flexible substrate 10 secures the mechanical strength of the portion where the drive mechanism for rotating the disk at the time of recording or reproducing information on the magneto-optical disk X1 mechanically contacts the disk. For example, a part of the drive mechanism has an opening 12a into which the drive mechanism is fitted, and is made of, for example, metal. Such a reinforcing hub 12 is provided within the thickness of the main portion 11 at the opening 11 a of the main portion 11, and is integrated with the main portion 11.

  The recording magnetic unit 21 has a laminated structure composed of a recording layer 21a, an intermediate layer 21b, and a reproducing layer 21c, and a magnetic domain expansion reproducing method (for example, DWDD, MAMMOS, etc.) accompanied by domain wall movement or magnetic domain expansion in the reproducing layer 21c. ) Is configured to be reproducible based on.

  The recording layer 21a is a part responsible for a recording function in the magneto-optical disk X1, is made of an amorphous alloy containing a rare earth element and a transition metal, and has a perpendicular magnetic anisotropy and is perpendicularly magnetized in the vertical direction. It is a magnetized film. The vertical direction means a direction perpendicular to the film surface of the magnetic film constituting the layer. Specifically, the recording layer 21a is made of a predetermined composition ratio such as TbFeCо or TbDyFeCо. The thickness of the recording layer 21a is, for example, 40 to 100 nm.

  The intermediate layer 21b is a part for changing the exchange coupling state of the recording layer 21a and the reproducing layer 21c. The intermediate layer 21b transitions from the perpendicular magnetization state to the spontaneous magnetization disappearance state at the Curie temperature when the temperature rises, and the Curie temperature due to the temperature fall. It is made of a rare earth-transition metal amorphous alloy that transitions from a spontaneous magnetization disappearance state to a perpendicular magnetization state. In the present embodiment, the Curie temperature of the intermediate layer 21b is, for example, 100 to 170 ° C. Therefore, the intermediate layer 21b is a perpendicular magnetization film at room temperature. Specifically, the intermediate layer 21b is made of, for example, TbFe or TbFeCо having a predetermined composition ratio. The thickness of the intermediate layer 21b is, for example, 10 to 30 nm.

  The reproducing layer 21c is a part that bears a reproducing function accompanied by domain wall movement or domain expansion, and is a perpendicular magnetization film made of a rare earth-transition metal amorphous alloy. Specifically, the reproducing layer 21c is made of, for example, GdFeCo or GdDyFeCo having a predetermined composition ratio. Further, the thickness of the reproduction layer 21c is, for example, 10 to 50 nm.

  The heat conductive layer 22 is a part for efficiently transmitting heat generated in the recording magnetic part 21 or the like to the flexible substrate 10 side when the recording or reproducing laser beam is irradiated to the magneto-optical disk X1. For example, it is made of a high thermal conductive material such as Al alloy (AlN, AlSi, AlTi, AlCr, etc.), Ag, Ag alloy (AgPdCuSi, AgPdCu, etc.), Au, or Pt. The thickness of the heat conductive layer 22 is, for example, 10 to 50 nm.

The dielectric layers 23 and 24 are parts for avoiding or suppressing an unreasonable magnetic influence or chemical influence from the outside on the recording magnetic part 21, for example, SiN, SiO ₂ , YSiO ₂ , ZnSiO ₂ , It consists of AlO or AlN. The thickness of the dielectric layers 23 and 24 is, for example, 30 to 100 nm.

  The protective film 25 is made of a resin material that covers the recording magnetic part 21 in order to protect the recording magnetic part 21 from dust and the like, and has sufficient permeability to the recording laser beam and the reproducing laser beam of the magneto-optical disk X1. Become. As the resin for forming the protective film 25, for example, an ultraviolet curable transparent resin is employed. The thickness of the protective film 25 is, for example, 5 to 50 μm.

  3 and 4 show some steps in the method of manufacturing the magneto-optical disk X1. 3 and 4, each process is represented by a cross-sectional view. In this method, first, as shown in FIG. 3A, a resin material 33 is supplied onto a substrate 32 supported by a spin table 31. The spin table 31 is configured to be rotationally driven around the rotation axis R at a desired rotational speed, has a shaft core 31a, and suction for sucking a member placed on the spin table 31. A mechanism (not shown) is provided. The substrate 32 has a pregroove forming surface 32a with a convex pattern corresponding to the above-mentioned pregroove 11b, and an opening 32b. The substrate 32 is fitted in the opening 32b to the shaft core 31a of the spin table 31, and is fixed to the spin table 31 by the suction action of the suction mechanism described above. In addition to the substrate 32, the above-described reinforcing hub 12 is also fitted on the shaft core 31a of the spin table 31 through the opening 12a. In the present embodiment, the resin material 33 is an ultraviolet curable resin. In the present invention, a thermosetting resin or a catalyst curable resin may be adopted as the resin material 33 instead of the ultraviolet curable resin. In this step, the resin material 33 in an uncured state is supplied in an annular shape around the reinforcing hub 12 on the substrate 32 while the spin table 31 is stationary.

  Next, as shown in FIG. 3B, the resin material 33 is spread to a predetermined degree in a state where the spin table 31 is rotationally driven at a predetermined first rotation speed and the substrate 32 is rotated. In this step, the degree of spreading of the resin material 33 can be adjusted by adjusting the rotational speed of the spin table 31 (that is, by adjusting the centrifugal force acting on the resin material 33).

  Next, as shown in FIG. 3C, a substrate 34 is installed above the resin material 33. The substrate 34 is a transparent substrate having a pregroove forming surface 34a with a convex pattern corresponding to the above-mentioned pregroove 11b and an opening 34b. In this step, such a substrate 34 is fitted into the shaft core 31a of the spin table 31 through the opening 34b. In this way, a laminate including the substrates 32 and 34, the reinforcing hub 12, and the resin material 33 is formed.

  Next, as shown in FIG. 3D, the resin material 33 is predetermined between the substrates 32 and 34 in a state where the spin table 31 is rotationally driven at a predetermined second rotational speed to rotate the above-described laminated body. Spread to the extent of. At this time, it is preferable to spread the resin material 33 until a part of the resin material 33 leaks from between the substrates 32 and 34. In this step, the extent or thinness of the resin material 33 can be adjusted by adjusting the rotation speed of the spin table 31. The second rotation speed is preferably higher than the first rotation speed in the process described above with reference to FIG. Thereafter, as required, as shown in FIG. 4A, the resin material 33 leaked from between the substrates 32 and 34 is removed.

  Next, as shown in FIG. 4B, the resin material 33 is irradiated with ultraviolet rays from the substrate 34 side to cure the resin material 33, and the pregroove forming surfaces 32a and 34a of the substrates 32 and 34 are projected. A main portion 11 having a pre-groove 11b corresponding to the pattern on the surface is formed. Thereby, the main part 11 derived from the resin material 33 and the reinforcing hub 12 are integrated. When a thermosetting resin or a catalyst curable resin is adopted as the resin material 33 instead of the ultraviolet curable resin, in this step, the resin material 33 is changed by heating or adding a catalyst instead of the ultraviolet irradiation. Harden.

  After the resin material 33 is cured, the flexible substrate 10 including the integrated main portion 11 and the reinforcing hub 12 is removed from between the substrates 32 and 34 as shown in FIG. The flexible substrate 10 can be manufactured as described above.

  In the spreading step described above with reference to FIG. 3D, the centrifugal force acting on the resin material 33 by rotating the substrates 32 and 34 and the laminate including the reinforcing hub 12 and the resin material 33 between the substrates. The resin material 33 can be spread thinly around the reinforcing hub 12 between the substrates 32 and 34 along the pregroove forming surfaces 32a and 34a of both the substrates 32 and 34. In the curing step described above with reference to FIG. 4B, the resin material 33 is cured, so that the pregrooves 11 b corresponding to the convex patterns of the pregroove forming surfaces 32 a and 34 a of both the substrates 32 and 34 are formed on both surfaces. The main part 11 and the reinforcing hub 12 can be integrated. Therefore, according to the method described above with reference to FIGS. 3 and 4, the reinforcing hub 12 having the pregroove 11b on both sides and sufficiently thin and having the opening 12a is integrated at a predetermined position. The flexible substrate 10 can be appropriately manufactured.

  In manufacturing the magneto-optical disk X1, next, the heat conductive layer 22, the dielectric layer 23, the recording layer 21a, the intermediate layer 21b, the reproducing layer 21c, and the dielectric layer 24 are formed on both surfaces of the main portion 11 of the flexible substrate 10. And the protective film 25 are sequentially formed. Each of the heat conductive layer 22 to the dielectric layer 24 can be formed by a sputtering method using a predetermined target. The protective film 25 can be formed by applying a predetermined ultraviolet curable resin on the dielectric layer 24 by spin coating and then curing the resin film by ultraviolet irradiation. The magneto-optical disk X1 can be manufactured as described above.

  When recording information on the magneto-optical disk X1, for example, a recording laser from a predetermined optical pickup or optical head that is positioned and controlled with respect to the magneto-optical disk X1 in a state where the disk is rotated at a predetermined rotational speed. The recording layer 21a in the recording magnetic part 21 is locally heated sequentially by irradiating the recording magnetic part 21 as a continuous pulse signal. At the same time, a recording magnetic field modulated in a predetermined manner is applied to the temperature-rising point by the magnetic recording head.

  At this time, as shown in FIG. 5, for example, as shown in FIG. 5, the stabilizer 5 is disposed close to the portion where the information recording is performed on the magneto-optical disk X1 from the side opposite to the side irradiated with the laser L. The stabilizer 5 has a front end surface 5a having a significant area, and the front end surface 5a is opposed to a surface opposite to the recording surface on which information recording is performed on the magneto-optical disk X1. As described above, by arranging the stabilizer 5 close to the magneto-optical disk X1, the so-called Bernoulli effect suppresses the deflection of the flexible magneto-optical disk X1. By arranging the stabilizer 5 close to the magneto-optical disk X1 that rotates at a predetermined rotational speed by driving the spindle motor M, the relative speed of, for example, air existing near the surface of the magneto-optical disk X1 with respect to the magneto-optical disk X1. Is faster between the magneto-optical disk X1 and the stabilizer 5 than on the laser irradiation side. Therefore, according to Bernoulli's law, the pressure near the surface of the magneto-optical disk X1 is smaller between the magneto-optical disk X1 and the stabilizer 5 than on the laser irradiation side. Due to this pressure difference, an apparent attraction force is generated between the magneto-optical disk X1 and the stabilizer 5, and the surface of the portion of the magneto-optical disk X1 where the stabilizer 5 is opposed by the attraction force acting. Shake is suppressed.

  In the flexible magneto-optical disk X1, as described above, predetermined information or signals can be recorded on the recording layer 21a as changes in the magnetization direction while suppressing the surface blur due to the Bernoulli effect.

  On the other hand, when information is reproduced from the magneto-optical disk X1, for example, a reproducing laser is emitted from a predetermined optical pickup or optical head toward the recording magnetic unit 21 while the disk is rotated at a predetermined rotational speed. The change of the polarization angle of the light reflected by the surface of the recording magnetic part 21 (reproducing layer 21c) is detected. At this time, as shown in FIG. 5, for example, as shown in FIG. 5, the stabilizer 5 is disposed close to the portion where the information reproduction is performed on the magneto-optical disk X1 from the side opposite to the side irradiated with the laser L. In the flexible magneto-optical disk X1, the recording signal in the recording magnetic unit 21 can be read while suppressing the surface blur due to the Bernoulli effect.

  In the magneto-optical disk X1, as described above, the flexible substrate 10 has the pregrooves 11b on both sides, and the reinforcing hub 12 is provided within the thickness of the main portion 11, and can be formed sufficiently thin. The magneto-optical disk X1 having such a thin flexible substrate 10 as a base material and having the recording magnetic portions 21 on both surfaces is suitable for achieving a high volume recording density by sufficiently reducing the thickness. In addition, the flexible substrate 10 of the magneto-optical disk X1 is formed by integrating the main portion 11 and the reinforcing hub 12 as described above. Such a configuration secures the strength of the portion where the spindle motor for rotating the magneto-optical disk X1 mechanically contacts the magneto-optical disk X1, and suppresses deformation or the like of the magneto-optical disk X1. In addition, it is preferable.

1 is a partial cross-sectional view of a magneto-optical disk according to the present invention. 1 is a plan view of a flexible substrate in a magneto-optical disk according to the present invention. FIG. 2 shows some steps in the method of manufacturing the magneto-optical disk shown in FIG. It is the process following FIG. It is a schematic diagram showing an aspect of information recording or information reproduction of the magneto-optical disk according to the present invention. It is a partial sectional view of a conventional magneto-optical disk. FIG. 7 shows some steps in the method of manufacturing the magneto-optical disk shown in FIG.

Explanation of symbols

X1, X2 magneto-optical disk 10 flexible substrate 11 main part 11a opening 11b pre-groove 12 reinforcing hub 12a opening 21, 62 recording magnetic part 22, 63 heat conduction layer 23, 24, 64, 65 dielectric layer 25, 66 protection Film 32, 34 Substrate 32a, 34a Pregroove forming surface 33 Resin material

Claims (4)

A first substrate having a first uneven surface, a second substrate having a second uneven surface facing the first uneven surface of the first substrate, and an uncured state interposed between the first and second substrates And a step of spreading the curable resin material between the first and second substrates by rotating a laminate including the curable resin material in
A step of curing the curable resin material. A first substrate having a first uneven surface, a second substrate having a second uneven surface opposite to the first uneven surface of the first substrate, and an opening between the first and second substrates And rotating the laminate including the reinforced resin material interposed between the first and second substrates around the reinforcing hub to rotate the first and second substrates. Spreading the curable resin material in between,
A step of curing the curable resin material. A first recording magnetic part and a second recording magnetic part;
A first substrate having a first uneven surface, a second substrate having a second uneven surface opposite to the first uneven surface of the first substrate, and an opening between the first and second substrates And rotating the laminated body including the reinforcing hub interposed between the first and second substrates around the reinforcing hub, thereby rotating the laminated body including the reinforcing hub interposed between the first and second substrates. step of spreading a pre-Symbol curable resin material Te between odor, and a flexible substrate located between the curable step of the resin material is cured, the through the are manufactured first and second recording magnetic part, A flexible magneto-optical recording medium. A main portion having a first pregroove surface and a second pregroove surface opposite to the first pregroove surface and having a first opening, and within the thickness of the main portion at the first opening A flexible substrate having a reinforcing hub provided and having a second opening;
A first recording magnetic part on the first pre-groove surface side;
Flexible magneto-optical recording medium and a second recording magnetic portion on the side of the second pregroove surface.

Images