Method for manufacturing magnetic recording medium and heat treatment apparatus used therefor

Abstract

To provide a method for manufacturing a magnetic recording medium, which can stably manufacture the magnetic recording medium, by preventing generation of ozone and achieving a good bonding strength between a protective film and a lubricant layer.SOLUTION: A method for manufacturing a magnetic recording medium includes successively laminating at least a magnetic layer, a protective film, and a lubricant layer on a nonmagnetic substrate 21, and performing two heat treatment surfaces 21a and 21b of the lubricant layer by irradiation of light from LED light sources 22 and 23.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a magnetic recording medium and a heat treatment apparatus used therein. [Background technology]

[0002] A hard disk device used as a storage device of an information processing device includes a magnetic head for reproducing and recording, and a magnetic recording medium having a magnetic layer. In the magnetic recording medium, a protective film layer and a lubricant layer are provided on the magnetic layer to prevent deterioration of the durability of the magnetic recording medium due to wear damage caused by contact sliding with the magnetic head. A hard carbon film has been generally used as the protective film layer. The lubricant layer is generally formed by applying a liquid perfluoropolyether compound or the like to the surface.

[0003] It is known that various treatments are performed on the lubricant layer in order to increase the bonding strength of the lubricant layer to the protective film layer. For example, Patent Document 1 discloses a method in which the applied lubricant layer is subjected to a heat treatment and then to a light irradiation treatment using an ultraviolet lamp. It also discloses that the light irradiation treatment is performed in an inert gas atmosphere or in a vacuum in order to suppress the generation of ozone during the light irradiation treatment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-25452 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, the light from the ultraviolet lamp decomposes oxygen to generate ozone, and so the light irradiation process is carried out in an inert gas atmosphere or in a vacuum. However, it has been revealed that even so, a small amount of ozone is generated, and that this ozone decomposes and destroys the lubricant molecules contained in the lubricant layer.

[0006] When we investigated the cause of this ozone generation, we found that a small amount of oxygen adsorbed on the surface of the magnetic recording medium was taken into the processing device and decomposed into ozone. The oxygen that is the source of ozone is, for example, moisture adsorbed on the substrate or the inner wall of the device, as well as atmospheric components that are taken into the processing device even if the inside of the processing device is filled with an inert gas atmosphere when the lubricant layer is processed in the atmosphere. In addition, since it is difficult to obtain parallel light from an ultraviolet lamp and the light spreads to the surroundings, the light is irradiated on things other than the processing substrate of the processing device, and the oxygen adsorbed on the inner wall of the processing device is also decomposed into ozone.

[0007] Even if an ultraviolet lamp with a peak wavelength range that does not generate ozone is used to suppress the decomposition of oxygen, the ultraviolet lamp contains weak light of various wavelengths other than the peak wavelength, and this weak light decomposes oxygen and generates ozone.

[0008] One aspect of the present invention has been made in consideration of the above circumstances, and aims to provide a method for manufacturing a magnetic recording medium that can stably produce a magnetic recording medium that suppresses ozone generation and has good bonding strength between a protective film layer and a lubricant layer, and a heat treatment device used therefor. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention employs the following configuration. (1) A method for manufacturing a magnetic recording medium, comprising laminating at least a magnetic layer, a protective film layer, and a lubricant layer in this order on a non-magnetic substrate, A method for manufacturing a magnetic recording medium, comprising: heat-treating the surface of the lubricant layer by irradiating the surface with light from an LED light source. (2) The method for producing a magnetic recording medium according to (1), wherein the light emitted from the LED light source has a central wavelength of less than 500 nm and does not include the central wavelength in the wavelength range of 170 nm to 190 nm. (3) The method for producing a magnetic recording medium according to (1) or (2), wherein the heat treatment is carried out under a pressure close to atmospheric pressure. (4) The method for producing a magnetic recording medium according to any one of (1) to (3), wherein the heat treatment is carried out in an air atmosphere. (5) The method for producing a magnetic recording medium according to any one of (1) to (4), wherein the heat treatment is carried out for 60 seconds or less. (6) A heat treatment apparatus for use in the method for producing a magnetic recording medium according to any one of (1) to (4), comprising: A first LED light source that emits light toward one surface of a substrate to heat the substrate; a second LED light source that emits light toward the other surface of the substrate to heat the substrate; a mechanism for supporting an outer peripheral end of the substrate by a support member and inserting the substrate into and out of a space between the first LED light source and the second LED light source; A heat treatment device comprising: (7) The heat treatment apparatus according to (6), wherein 50% or more of the light from the first LED light source and the second LED light source is directly irradiated onto the substrate. (8) The heat treatment apparatus according to (6) or (7), wherein a distance between the first LED light source and the substrate and between the second LED light source and the substrate is 50 mm or less. (9) The heat treatment device according to any one of (6) to (8), wherein the light emitted from the first LED light source and the second LED light source has a central wavelength of less than 500 nm and does not include a wavelength range of 170 nm to 190 nm. (10) The heat treatment apparatus according to any one of (6) to (9), further comprising a control device that causes the first LED light source and the second LED light source to emit light only when the substrate is placed between the first LED light source and the second LED light source. Effect of the Invention

[0010] According to one aspect of the method for producing a magnetic recording medium of the present invention, the generation of ozone can be suppressed when the surface of the lubricant layer of the magnetic recording medium is heat-treated, thereby making it possible to stably produce a magnetic recording medium having good bonding strength between the protective film layer and the lubricant layer.

[0011] In addition, in the method for manufacturing a magnetic recording medium according to one embodiment of the present invention, since the light from the LED light source can have a substantially uniform light intensity on the irradiated surface, it is possible to manufacture a magnetic recording medium having a uniform in-plane distribution of the bonding strength between the protective film layer and the lubricant layer.

[0012] In the heat treatment apparatus of the present invention, the LED light source emits light only when the substrate to be treated is placed between the pair of LED light sources, so that the heat rays from one LED light source do not deteriorate the other LED light source, and thus a long life can be realized. In addition, in the heat treatment apparatus of the present invention, the LED light source emits light only during heat treatment, so that power consumption can be reduced.

[0013] Furthermore, since the heat treatment apparatus according to one embodiment of the present invention can be used in the atmosphere, the productivity of the magnetic recording media can be improved. [Brief description of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing an example of a magnetic recording medium. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of a heat treatment apparatus used in the manufacture of a magnetic recording medium. [Diagram 3] FIG. 2 is a schematic perspective view showing an example of a light source of the heat treatment apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same components in each drawing are given the same reference numerals, and duplicated descriptions are omitted. In addition, the scale of each member in the drawings may differ from the actual scale. In this specification, "~" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits, unless otherwise specified.

[0016] Before describing the method for producing a magnetic recording medium according to an embodiment of the present invention and the heat treatment apparatus used therein, the magnetic recording medium obtained by the method for producing a magnetic recording medium according to this embodiment will be described.

[0017] <Magnetic recording media> Fig. 1 is a schematic cross-sectional view showing an example of a magnetic recording medium. As shown in Fig. 1, a magnetic recording medium 10 is a laminate in which a magnetic layer 12, a protective film layer 13, and a lubricant layer 14 are laminated in this order on a non-magnetic substrate 11.

[0018] In this embodiment, an example will be described in which an adhesion layer (not shown), a soft magnetic underlayer (not shown), a seed layer (not shown), and an orientation control layer (not shown) are laminated in this order between the non-magnetic substrate 11 and the magnetic layer 12. The adhesion layer, the soft magnetic underlayer, the seed layer, and the orientation control layer are provided as necessary, and some or all of them may not be provided.

[0019] A laminate in which a film made of NiP or a NiP alloy is formed on a base made of a metal material such as Al or an alloy material such as an Al alloy can be used as the nonmagnetic substrate 11. Alternatively, a substrate made of a nonmetallic material such as glass, ceramics, silicon, silicon carbide, carbon, or resin can be used as the nonmagnetic substrate 11, or a laminate in which a film of NiP or a NiP alloy is formed on a base made of such a nonmetallic material can be used.

[0020] The adhesion layer suppresses the progress of corrosion of the non-magnetic substrate 11 when the non-magnetic substrate 11 and the soft magnetic underlayer provided on the adhesion layer are arranged in contact with each other. The material of the adhesion layer can be appropriately selected from, for example, Cr, Cr alloy, Ti, Ti alloy, etc. The thickness of the adhesion layer is preferably 2 nm or more so that the effect of providing the adhesion layer can be sufficiently obtained. The adhesion layer can be formed, for example, by a sputtering method.

[0021] In this specification, the thickness of the adhesive layer refers to the length in the direction perpendicular to the main surface of the adhesive layer. The thickness of the adhesive layer is, for example, the thickness measured at any point on the cross section of the adhesive layer. When the thickness is measured at several points on the cross section of the adhesive layer, the average value of the thicknesses at these measurement points may be used. The same measurement method as that for the thickness of the adhesive layer can be used for other layers.

[0022] The soft magnetic underlayer preferably has a structure in which a first soft magnetic film, an intermediate layer made of a Ru film, and a second soft magnetic film are laminated in this order. That is, the soft magnetic underlayer preferably has a structure in which the soft magnetic films above and below the intermediate layer are anti-ferro-coupling (AFC)-coupled by sandwiching the intermediate layer made of a Ru film between two soft magnetic films. The soft magnetic underlayer having an AFC-coupled structure can increase resistance to external magnetic fields and resistance to the WATE (Wide Area Tack Erasure) phenomenon, which is a problem specific to perpendicular magnetic recording.

[0023] The thickness of the soft magnetic underlayer is preferably 15 nm to 80 nm, and more preferably 20 nm to 50 nm. If the thickness of the soft magnetic underlayer is 15 nm or more, the magnetic flux from the magnetic head can be sufficiently absorbed, and insufficient writing can be prevented, thereby preventing deterioration of the recording and reproducing characteristics. On the other hand, if the thickness of the soft magnetic underlayer is 80 nm or less, a significant decrease in productivity can be prevented.

[0024] The first and second soft magnetic films are preferably made of a CoFe alloy. When the first and second soft magnetic films are made of a CoFe alloy, a high saturation magnetic flux density Bs (1.4 (T) or more) can be realized. In addition, it is preferable to add at least one of Zr, Ta, and Nb to the CoFe alloy used for the first and second soft magnetic films. This promotes the amorphization of the first and second soft magnetic films, improves the orientation of the seed layer formed on the soft magnetic underlayer, and reduces the flying height of the magnetic head.

[0025] The soft magnetic underlayer can be formed by, for example, a sputtering method.

[0026] The seed layer controls the orientation and crystal size of the orientation control layer and magnetic layer 12 provided thereon. By providing the seed layer, the perpendicular component of the magnetic flux generated from the magnetic head with respect to the substrate surface is increased, and the magnetization direction of the magnetic layer 12 is more firmly fixed in the direction perpendicular to the nonmagnetic substrate 11.

[0027] The seed layer is preferably made of a NiW alloy. When the seed layer is made of a NiW alloy, other elements such as B, Mn, Ru, Pt, Mo, and Ta may be added to the NiW alloy as necessary.

[0028] The seed layer preferably has a thickness of 2 nm to 20 nm. If the seed layer has a thickness of 2 nm or more, the effect of providing the seed layer can be sufficiently obtained. If the seed layer has a thickness of 20 nm or less, the crystal size can be prevented from becoming large.

[0029] The seed layer can be formed by, for example, a sputtering method.

[0030] The orientation control layer controls the orientation of the magnetic layer 12 so that it is well oriented. The orientation control layer is preferably made of Ru or a Ru alloy. The thickness of the orientation control layer is preferably 5 nm to 30 nm. If the thickness of the orientation control layer is 30 nm or less, the distance between the magnetic head and the soft magnetic underlayer is small, and the magnetic flux from the magnetic head can be made steep. If the thickness of the orientation control layer is 5 nm or more, the orientation of the magnetic layer 12 can be well controlled.

[0031] The orientation control layer may be composed of one layer or multiple layers. When the orientation control layer is composed of multiple layers, all of the orientation control layers may be made of the same material, or at least some of the layers may be made of different materials.

[0032] The orientation control layer can be formed by a sputtering method.

[0033] The magnetic layer 12 is made of a magnetic film with an easy axis of magnetization oriented in a direction substantially perpendicular to the surface of the nonmagnetic substrate 11. The magnetic layer 12 contains Co and Pt, and may further contain oxides, Cr, B, Cu, Ta, Zr, etc., in order to improve the SNR characteristics. Examples of oxides contained in the magnetic layer 12 include SiO2, SiO, Cr2O3, CoO, Ta2O3, and TiO2.

[0034] The magnetic layer 12 may be composed of one layer, or may be composed of multiple layers with different compositions. For example, when the magnetic layer 12 is composed of three layers, a first magnetic layer, a second magnetic layer, and a third magnetic layer, the first magnetic layer is preferably composed of a material having a granular structure containing Co, Cr, and Pt and further containing an oxide. As the oxide contained in the first magnetic layer, it is preferable to use oxides such as Cr, Si, Ta, Al, Ti, Mg, and Co. Among them, TiO2, Cr2O3, SiO2, etc. can be particularly preferably used. In addition, the first magnetic layer is preferably composed of a composite oxide to which two or more kinds of oxides are added. Among them, Cr2O3-SiO2, Cr2O3-TiO2, SiO2-TiO2, etc. can be particularly preferably used.

[0035] The second magnetic layer may be made of the same material as the first magnetic layer, and is preferably made of a material having a granular structure.

[0036] The third magnetic layer is preferably made of a material having a non-granular structure that contains Co, Cr, and Pt and does not contain oxides. The third magnetic layer may contain one or more elements selected from B, Ta, Mo, Cu, Nd, W, Nb, Sm, Tb, Ru, Re, and Mn in addition to Co, Cr, and Pt. By containing the above elements in addition to Co, Cr, and Pt, the third magnetic layer can promote the miniaturization of magnetic particles or improve the crystallinity and orientation, so that the magnetic recording medium 10 can have recording and reproducing characteristics and thermal fluctuation characteristics suitable for higher density recording.

[0037] The thickness of the magnetic layer 12 is preferably 5 nm to 25 nm. If the thickness of the magnetic layer 12 is 5 nm or more, sufficient reproduction output can be obtained and thermal fluctuation characteristics can be maintained. Furthermore, if the thickness of the magnetic layer 12 is 25 nm or less, the enlargement of magnetic particles in the magnetic layer 12 is suppressed, the increase in noise during recording and reproduction is suppressed, and the deterioration of recording and reproduction characteristics, such as the signal / noise ratio (S / N ratio) and the recording characteristics (OW), is suppressed.

[0038] In order to achieve a higher recording density, the magnetic layer 12 is preferably a magnetic layer for perpendicular magnetic recording in which the axis of easy magnetization is oriented in a direction substantially perpendicular to the substrate surface of the non-magnetic substrate 11. The magnetic layer 12 may be for in-plane magnetic recording.

[0039] The magnetic layer 12 may be formed by any method commonly used in the past, such as a vapor deposition method, an ion beam sputtering method, a magnetron sputtering method, etc. The magnetic layer 12 is usually formed by a sputtering method such as an ion beam sputtering method or a magnetron sputtering method.

[0040] The protective film layer 13 is provided on the upper surface of the magnetic layer 12 to protect the magnetic layer 12. Carbon-based materials such as CVD carbon formed by plasma CVD, amorphous carbon, hydrogen-containing carbon, nitrogen-containing carbon, and fluorine-containing carbon, and ceramic materials such as silica and zirconia can be used as the protective film layer 13. Among them, hard and dense CVD carbon is preferably used not only from the viewpoint of durability but also from the viewpoint of economy and productivity. The thickness of the protective film layer 13 is set to 10 Å to 150 Å (1 nm to 15 nm), preferably 20 Å to 60 Å (2 nm to 6 nm), in order to improve durability and reduce loss during recording and reproduction.

[0041] The lubricant layer 14 is provided on the upper surface of the protective film layer 13, and is the uppermost layer of the magnetic recording medium 10. The lubricant layer 14 may contain, for example, a polymer of a perfluoropolyether compound containing a polymerizable unsaturated group. As the perfluoropolyether compound containing a polymerizable unsaturated group, a compound in which an organic group having a polymerizable unsaturated bond is bonded to at least one end of a perfluoropolyether main chain may be used.

[0042] <Method of manufacturing magnetic recording medium> The method for producing a magnetic recording medium according to the present embodiment includes a step of laminating a magnetic layer 12 and a protective film layer 13 in this order on a non-magnetic substrate 11, laminating a lubricant layer 14 on the surface of the protective film layer 13, and then heat-treating the surface of the lubricant layer 14 by irradiating light from an LED light source (a first LED light source 22 and a second LED light source 23, which will be described later). The method for producing a magnetic recording medium according to the present embodiment employs such a heat-treating step, which prevents oxygen from being decomposed and generating ozone in the heat-treating step, and therefore allows a magnetic recording medium having a good bonding strength between the protective film layer 13 and the lubricant layer 14 to be stably produced. The effect of increasing the bonding strength between the protective film layer 13 and the lubricant layer 14 is not only due to the heating effect caused by the light irradiation, but also due to the light irradiation from the LED light source, which changes the molecular structure of the lubricant molecules contained in the lubricant layer 14, thereby increasing the bonding strength between the lubricant molecules contained in the lubricant layer 14 and the protective film layer 13, thereby allowing a magnetic recording medium having a good bonding strength between the protective film layer 13 and the lubricant layer 14 to be obtained.

[0043] That is, compared to conventionally used ultraviolet lamps, LED light sources can easily produce parallel light and prevent the light from spreading to the surroundings, preventing the light from being irradiated onto areas other than the substrate to be processed and the generation of ozone through the decomposition of oxygen adsorbed on the walls of the device, etc. Also, because the wavelength range of the emitted light is narrow, it is easy to design a light source that prevents the decomposition of oxygen and the generation of ozone.

[0044] The light emitted from the LED light source (LED light) preferably has a central wavelength of less than 500 nm and does not include the wavelength range of 170 nm to 190 nm. This is because light with a central wavelength in the wavelength range of 170 nm to 190 nm often decomposes oxygen to generate ozone.

[0045] By using such an LED light source, it is possible to suppress the LED light from decomposing oxygen to generate ozone. Therefore, in the method for producing a magnetic recording medium according to this embodiment, the heat treatment can be performed in the atmosphere, i.e., under a pressure close to atmospheric pressure or in an atmospheric atmosphere, and the heating device can be simplified, so that the manufacturing costs of the magnetic recording medium and the heating device can be reduced.

[0046] Since the LED light source can give directionality to the light it emits, the directionality of the heat rays emitted from the LED light source is also higher than that of other heating means. Therefore, the heat rays can be concentrated on the substrate to be processed in the heating device, and the heat rays can be prevented from hitting members other than the substrate to be processed, i.e., the support member for the substrate to be processed and the inner wall of the heating device, etc., thereby increasing the heating processing speed.

[0047] In the method for producing a magnetic recording medium according to the present embodiment, the heat treatment is preferably carried out within 60 seconds, more preferably within 20 seconds. By shortening the treatment time in this manner, the manufacturing cost of the magnetic recording medium can be reduced, and the risk of contamination of the magnetic recording medium during the heat treatment can be reduced.

[0048] <Heat treatment equipment> Fig. 2 is a schematic cross-sectional view showing an example of a heat treatment apparatus used in the manufacture of a magnetic recording medium according to an embodiment of the present invention, and Fig. 3 is a schematic perspective view showing an example of a light source of the heat treatment apparatus. As shown in Fig. 2, the heat treatment apparatus 20 includes a first LED light source 22 that emits (irradiates) light (first light) onto one surface (heat treatment surface) 21a of the substrate 21 to heat the substrate 21, a second LED light source 23 that emits light (second light) onto the other surface (heat treatment surface) 21b of the substrate 21 to heat the substrate 21, and a mechanism 25 that supports the outer peripheral end 21c of the substrate 21 with a support member 24 and moves the substrate 21 between the first LED light source 22 and the second LED light source 23. In Fig. 2, the mechanism 25 that moves the substrate 21 and the support member 24 has a function of lifting and lowering the substrate 21 up and down as indicated by the arrow.

[0049] 3, the LED light source 30 constituting the first LED light source 22 and the second LED light source 23 is composed of a large number of LED elements 32 attached to the main body 31 of the LED light source 30. The large number of LED elements 32 attached to the main body 31 of the LED light source 30 are disposed so as to face the two heat treatment surfaces 21a and 21b of the substrate 21 shown in FIG.

[0050] Each LED element 32 is arranged so that the light emitted has directivity with a central axis perpendicular to the main surface 31a of the body 31 of the LED light source 30. The directivity of the LED element 32 is preferably within ±60° with respect to the central axis.

[0051] Here, the directivity angle of the LED element 32 is defined as the angle with respect to the central axis at which the illuminance becomes 50% when the illuminance of the central axis is 100% with the position where the LED element 32 shines most brightly as the central axis. Since the substrate 21 has an opening in the center, the LED light source 30 does not need to provide the LED element 32 near the center of the main body 31.

[0052] As described above, the heat treatment apparatus 20 includes the first LED light source 22 and the second LED light source 23, and by using the LED light source 30 having the configuration shown in Fig. 3 for the first LED light source 22 and the second LED light source 23, both surfaces (heat treatment surfaces 21a, 21b) of the substrate 21 can be heat-treated at high speed. Therefore, by using the magnetic recording medium 10 as the substrate 21, the heat treatment apparatus 20 can heat-treat both surfaces of the magnetic recording medium at high speed, thereby increasing the productivity of the magnetic recording medium 10.

[0053] In the heat treatment apparatus 20, it is preferable that 50% or more of the light from the first LED light source 22 and the second LED light source 23 is directly irradiated onto the substrate 21. By adopting such a configuration, the heat treatment apparatus 20 can concentrate the heat rays emitted from the first LED light source 22 and the second LED light source 23 onto the substrate 21 and prevent the heat rays from being irradiated onto members other than the substrate 21, thereby increasing the treatment speed and suppressing the generation of impurities.

[0054] In the heat treatment apparatus 20, the distance L between the substrate 21 and the first LED light source 22 and the second LED light source 23 is preferably 50 mm or less. By adopting such a configuration, the heat treatment apparatus 20 can concentrate the heat rays emitted from the first LED light source 22 and the second LED light source 23 on the substrate 21, thereby increasing the treatment speed.

[0055] In the heat treatment device 20, it is preferable that the light emitted from the first LED light source 22 and the second LED light source 23 has a central wavelength of less than 500 nm and does not include the wavelength range of 170 nm to 190 nm. By making the light emitted from the first LED light source 22 and the second LED light source 23 not include the wavelength range of 170 nm to 190 nm, it is possible to suppress the decomposition of oxygen and the generation of ozone.

[0056] By using the first LED light source 22 and the second LED light source 23 having the above-described configuration, the heat treatment apparatus 20 can reduce the generation of ozone caused by the decomposition of oxygen by light.

[0057] The heat treatment apparatus 20 preferably includes a control device that causes the first LED light source 22 and the second LED light source 23 to emit light only when the substrate 21 is placed between the first LED light source 22 and the second LED light source 23. Note that the substrate 21 being placed between the first LED light source 22 and the second LED light source 23 refers to the substrate 21 being in the state shown in FIG.

[0058] By adopting such a configuration, the heat treatment device 20 can reduce deterioration of one of the first LED light source 22 and the second LED light source 23 due to heat generated when the other LED light source is irradiated with light from the other LED light source. Also, the heat treatment device 20 can extend the life of the first LED light source 22 and the second LED light source 23 by making the first LED light source 22 and the second LED light source 23 emit light only during heat treatment, and can reduce the power consumption of the heat treatment device 20.

[0059] In addition, conventionally used ultraviolet lamps have difficulty in turning on and off in 60 seconds or less, and require about an hour for the light emission to stabilize. On the other hand, in this embodiment, the first LED light source 22 and the second LED light source 23 can be easily turned on and off at high speed, and the light emission is stable. Therefore, by using the first LED light source 22 and the second LED light source 23, the heat treatment device 20 can increase the productivity of the magnetic recording medium 10 having a good bonding strength between the protective film layer 13 and the lubricant layer 14.

[0060] Although the embodiment has been described above, the above embodiment is presented as an example, and the present invention is not limited to the above embodiment. The above embodiment can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0061] 10 Magnetic recording media 11 Non-magnetic substrate 12 Magnetic layer 13 Protective film layer 14 Lubricant layer 20 Heat treatment equipment 21 Substrate 22 1st LED light source 23 2nd LED light source 24 Support member 25 Mechanism 30 LED light sources 32 LED elements

Claims

1. A method for manufacturing a magnetic recording medium, comprising laminating at least a magnetic layer, a protective film layer, and a lubricant layer in this order on a non-magnetic substrate, comprising: A method for manufacturing a magnetic recording medium, comprising: heat-treating the surface of the lubricant layer by irradiating the surface with light from an LED light source.

2. 2. The method for producing a magnetic recording medium according to claim 1, wherein the light emitted from the LED light source has a central wavelength of less than 500 nm and does not include the central wavelength range of 170 nm to 190 nm.

3. 3. The method for producing a magnetic recording medium according to claim 1, wherein the heat treatment is carried out under a pressure close to atmospheric pressure.

4. 3. The method for producing a magnetic recording medium according to claim 1, wherein the heat treatment is carried out in an air atmosphere.

5. 3. The method for producing a magnetic recording medium according to claim 1, wherein the heat treatment is carried out for 60 seconds or less.

6. A heat treatment device used in the method for producing a magnetic recording medium according to claim 1, A first LED light source that emits light toward one surface of a substrate to heat the substrate; a second LED light source that emits light toward the other surface of the substrate to heat the substrate; a mechanism for supporting an outer peripheral end of the substrate by a support member and inserting the substrate into and out of a space between the first LED light source and the second LED light source; A heat treatment device comprising:

7. The heat treatment apparatus according to claim 6 , wherein 50% or more of the light from the first LED light source and the second LED light source is directly irradiated onto the substrate.

8. The heat treatment apparatus according to claim 6 , wherein a distance between the first LED light source and the substrate and between the second LED light source and the substrate is 50 mm or less.

9. 8. The heat treatment apparatus according to claim 6, wherein the light emitted from the first LED light source and the second LED light source has a central wavelength of less than 500 nm and does not include a wavelength range of 170 nm to 190 nm.

10. The heat treatment apparatus according to claim 6 , further comprising a control device that causes the first LED light source and the second LED light source to emit light only when the substrate is placed between the first LED light source and the second LED light source.

Images