JP2009151909A - Method of manufacturing optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical information recording medium having a two-or-more-layered structure that makes it hard to form rugged portions on a clamp part of a substrate when layers are formed on the substrate by a spin coat method, reduces the occurrence rate of radial linear defects caused when the protrusion is formed at the peripheral part of the clamp part of the substrate, and is excellent in optical characteristics during reproduction and/or recording. <P>SOLUTION: The method is provided for manufacturing an optical information recording medium having a plurality of layers sequentially laminated on a substrate having a through-hole at its center, in which at least two of the plurality of layers are formed by a spin coat method while center caps each having a predetermined radius are fitted into the through-hole. A radius of a first center cap used for forming an upper layer of the at least two layers is larger than a radius of a second center cap used for forming a lower layer thereof. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical information recording medium including a step of forming a layer on a substrate by spin coating using a center cap.

  In recent years, high-density optical information recording media have been proposed in which information signals are reproduced and / or recorded by irradiating light from the side of the substrate on which the information layer is formed. FIG. 1 is a cross-sectional view illustrating the configuration of an optical information recording medium having a two-layer structure in which information signals are reproduced and / or recorded by irradiating light from the side of the substrate on which the information layer is formed. . In FIG. 1, 10 is an optical information recording medium, 11 is a substrate, 12 is a reflective layer and / or recording layer, 13 is an intermediate layer, 14 is a second reflective layer and / or second recording layer, 15 is a cover layer, 16 Indicates a laser beam, and 17 indicates an objective lens.

  In the optical information recording medium 10 shown in FIG. 1, the substrate 11 has a thickness of about 1.1 mm, and is produced by, for example, injection molding of polycarbonate or the like, and has known pits and / or guide grooves on one surface. It has a provided structure. The reflective layer and / or recording layer 12, the intermediate layer 13, the second reflective layer and / or second recording layer 14, and the cover layer 15 are sequentially stacked on the pits and / or guide grooves of the substrate 11.

  The reflective layer and / or recording layer 12 and the second reflective layer and / or second recording layer 14 are information layers made of an aluminum alloy or the like. The second reflective layer and / or the second recording layer 14 semi-transmits light in order to enable reproduction and / or recording on the reflective layer and / or recording layer 12 on the back side when viewed from the laser beam 16. It has such a layer structure. The thickness of the reflective layer and / or recording layer 12 is, for example, 20 nm, and the thickness of the second reflective layer and / or second recording layer 14 is, for example, 8 nm.

  The intermediate layer 13 is a layer that separates the reflective layer and / or the recording layer 12 from the second reflective layer and / or the second recording layer 14, and the surface of the intermediate layer 13 is 2P using an ultraviolet curable resin or the like. Pits and / or guide grooves are formed by the transfer method or the like, and the thickness thereof is, for example, 25 μm.

  The cover layer 15 is formed of a light transmissive ultraviolet curable resin or the like, and has a thickness of, for example, 75 μm. Laser light 16 emitted from a light source (not shown) is collected by the objective lens 17 and passes through the cover layer 15 to reflect the reflection layer and / or the recording layer 12 or the second reflection layer and / or the second recording layer. 14 is irradiated. Hereinafter, the reflective layer and / or the recording layer is referred to as an information layer as necessary.

  FIG. 2 is a schematic view illustrating the appearance of a substrate constituting the optical information recording medium. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. 11a shows a center hole and 11b shows a clamp part. A substrate 11 constituting an optical information recording medium 10 as shown in FIG. 1 generally has a circular shape having a center hole 11a as a through hole at the center as shown in FIG. The clamp part 11b is provided in a predetermined area around the center hole 11a, and is clamped when the substrate 11 is completed as the optical information recording medium 10 and is mounted on an information recording / reproducing apparatus (not shown).

  In a high-density optical information recording medium as shown in FIG. 1, it is necessary to form a cover layer 15 having a uniform thickness on the substrate 11. Therefore, a method has been proposed in which a cover layer 15 having a uniform film thickness is formed on the substrate 11 by uniformly applying and curing an ultraviolet curable resin (resin) on the substrate 11 by spin coating. .

  Hereinafter, a method for forming the intermediate layer 13 and the cover layer 15 by the spin coating method in the optical information recording medium 10 having a two-layer structure will be described with reference to FIGS. FIG. 3 is a view illustrating a conventional center cap 25 used when forming a layer on a substrate by a spin coating method. 3A is a sectional view, FIG. 3B is a front view, and FIG. 3C is a bottom view. The center cap 25 shown in FIG. 3 is provided concentrically with the fitting portion 25c fitted into the center hole 11a of the substrate 11 and the fitting portion 25c, and the fitting portion 25c is fitted into the center hole 11a of the substrate 11. When combined, an umbrella-shaped portion 25b having an end face 25e made of an annular plane that is parallel to the substrate 11 and has a diameter larger than that of the fitting portion 25c, and an umbrella-shaped portion on the upper portion of the umbrella-shaped portion 25b 25b and a cylindrical protrusion 25a provided concentrically.

Further, the end face 25e, which is a part in contact with the substrate 11, is a flat ring-shaped flat part that is flat on the entire surface. In addition, when the end face 25e of the center cap 25 abuts on the substrate 11, a very small gap is generated, but this is also referred to as abutment. In FIG. 3, R ₁ indicates the radius of the center cap 25.

  4 to 15 are cross-sectional views for explaining a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the optical information recording medium 10 having a two-layer structure. 4 to 15, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and the description thereof is omitted. First, as shown in FIG. 4, it is a mounting table that can rotate by fitting the center hole 11 a of the substrate 11 sputtered with an aluminum alloy or the like as the reflective layer and / or the recording layer 12 to the substrate positioning portion 22. Place on the turntable 21. Then, the fitting portion 25 c of the center cap 25 shown in FIG. 3 is fitted into the center hole 11 a of the substrate 11.

  Next, as shown in FIG. 5, after the ultraviolet curable resin 33 is applied to the center of the substrate 11, the turntable 21 is rotated. As a result, as shown in FIG. 6, the intermediate layer 13 made of the ultraviolet curable resin 33 having a uniform film thickness is formed on the substrate 11. Next, as shown in FIG. 7, the center cap 25 is moved upward. Then, as shown in FIG. 8, a transparent stamper 34 having predetermined pits and / or guide grooves formed on the lower surface 34 b is placed on the intermediate layer 13. Further, as shown in FIG. 9, ultraviolet rays 35 are irradiated from above the upper surface 34a of the stamper 34 while transferring predetermined pits and / or guide grooves. Thereafter, as shown in FIG. 10, the intermediate layer 13 having predetermined pits and / or guide grooves is formed by moving the stamper 34 upward.

Further, after the second reflective layer and / or the second recording layer 14 is formed on the intermediate layer 13 by sputtering an aluminum alloy or the like, the center hole 11a of the substrate 11 is again formed on the substrate positioning portion as shown in FIG. The fitting portion 25 c of the center cap 25 is fitted into the center hole 11 a of the substrate 11 so as to be fitted to the rotation table 21. Next, as shown in FIG. 12, after the ultraviolet curable resin 33 is applied to the center of the substrate 11, the turntable 21 is rotated so that the ultraviolet light having a uniform film thickness is formed on the substrate 11 as shown in FIG. 13. The cover layer 15 made of the cured resin 33 is formed. Next, as shown in FIG. 14, the center cap 25 is moved upward and removed. Next, as shown in FIG. 15, the ultraviolet curable resin 33 is cured by irradiating the ultraviolet curable resin 33 from above the ultraviolet curable resin 33, thereby forming the cover layer 15 made of the ultraviolet curable resin 33. The optical information recording medium 10 is completed (see, for example, Patent Documents 1 to 4).
Japanese Patent Application Laid-Open No. 11-213459 JP 2004-95108 A JP 2006-59454 A JP 2006-331666 A

However, in the conventional manufacturing method of the optical information recording medium 10 having the two-layer structure shown in FIGS. 4 to 15, the center layer 13 and the cover layer 15 are formed at the center as shown in FIG. When dripping ultraviolet curable resin 33 in liquid form in the cap 25 on, since the ultraviolet curing resin 33 of the liquid soak by capillarity to the slight gap T ₁ of the the end face 25e and the substrate 11 of the center cap 25, rotates the rotary table 21 After that, when the liquid ultraviolet curable resin 33 is irradiated with the ultraviolet rays 35 to cure the liquid ultraviolet curable resin 33, the intermediate layer 13 and the cover layer 15 are separated from the substrate 11 as shown in FIG. Slight uneven portions 13a and 15a are formed on the clamp portion 11b, and the peripheral portion of the clamp portion 11b (the end portion of the center cap 25) is formed. The convex portions 13b and 15b may be formed.

The convex portion 13b of the intermediate layer 13 formed on the peripheral portion of the clamp portion 11b (the end portion of the center cap 25) adversely affects the formation of the cover layer 15. A second reflective layer and / or second recording layer 14 is formed on the intermediate layer 13 on which the convex portions 13b are formed by sputtering aluminum alloy or the like. Thereafter, an ultraviolet curable resin 33 is dropped on the center cap 25 as shown in FIG. 12 using the center cap 25 having the same radius R ₁ as that used when forming the intermediate layer 13. When rotated and shaken as shown in FIG. 13, the ultraviolet curable resin 33 is directly affected by the convex portion 13b formed in the peripheral portion of the clamp portion 11b (the end portion of the center cap 25) and spreads uniformly. Absent. As a result, a large number of radial line defects 36 as shown in FIG. 18 are generated in the cover layer 15, and there is a problem that optical characteristics such as jitter and error rate during reproduction and / or recording are deteriorated. It was.

  Such a problem cannot be solved by, for example, a center cap disclosed in Patent Document 3 having a structure in which the surface in contact with the substrate is concave and creates a space with the substrate. That is, the center cap disclosed in Patent Document 3 can improve the appearance defect of the clamp portion in the optical information recording medium having a single-layer structure, but regarding the application method to the optical information recording medium having two or more layers. It is not specifically disclosed.

  Further, for example, the technique disclosed in Patent Document 4 for changing the inner diameters of the intermediate layer and the cover layer is intended for an optical information recording medium in which the intermediate layer is formed by bonding sheets. The above-mentioned problems when forming an intermediate layer or a cover layer by a spin coating method using a cap cannot be solved.

  The present invention has been made in view of the above, and when a layer is formed on a substrate by spin coating, it is difficult to form an uneven portion on the clamp portion of the substrate, and the peripheral portion of the clamp portion of the substrate. The present invention provides a method for producing an optical information recording medium having two or more layers, which reduces the incidence of radial line defects caused by the formation of convex portions and has excellent optical characteristics during reproduction and / or recording. Objective.

  In order to achieve the above object, the present invention provides an optical information recording medium in which a plurality of layers are sequentially laminated on a substrate having a through hole in the center, and at least two of the plurality of layers are formed as the through holes. A center cap having a predetermined radius is fitted to the optical information recording medium, and formed by spin coating. The center cap used for forming an upper layer of the at least two layers has a radius of at least It is characterized by being larger than the radius of the center cap used for forming the lower layer of the two layers.

  According to the present invention, when the layer is formed on the substrate by the spin coating method, it is difficult to form the uneven portion on the clamp portion of the substrate, and the convex portion is formed on the peripheral portion of the clamp portion of the substrate. Accordingly, it is possible to provide a method of manufacturing an optical information recording medium having two or more layers, which has a reduced incidence of radial linear defects caused by the above, and has excellent optical characteristics during reproduction and / or recording.

  The best mode for carrying out the present invention will be described below with reference to the drawings. The optical information recording medium and optical information recording medium manufacturing method according to the present invention include, for example, a write-once optical information recording medium such as BD-R, for example, a rewritable optical information recording medium such as BD-RE, For example, the present invention can be applied to a read-only optical information recording medium such as a BD-ROM. In this embodiment, a read-only optical information recording medium will be described as an example.

<Example 1>
FIG. 19 is a cross-sectional view illustrating the optical information recording medium 100 according to the first embodiment of the invention. In the optical information recording medium 100 shown in FIG. 19, the substrate 110 has a thickness of about 1.1 mm, is produced by injection molding of polycarbonate, and has a structure in which known pits are provided on one surface. Although the external appearance of the substrate 110 is the same as the external appearance of the substrate 11 shown in FIG. 2, illustration thereof is omitted, but the substrate 110 has a circular shape having a center hole 110 a that is a through hole in the center. The clamp part 110b is provided in a predetermined area around the center hole 110a, and is clamped when the substrate 110 is completed as the optical information recording medium 100 and is attached to the information recording / reproducing apparatus.

  The reflective layer 120, the intermediate layer 130, the second reflective layer 140, and the cover layer 150 are sequentially stacked on the pits of the substrate 110. The reflective layer 120 and the second reflective layer 140 are information layers made of an aluminum alloy or the like. The second reflective layer 140 has a layer configuration that semi-transmits light in order to enable reproduction and / or recording on the reflective layer 120 on the back side when viewed from the laser beam 160. The thickness of the reflective layer 120 is, for example, 20 nm, and the thickness of the second reflective layer 140 is, for example, 8 nm.

  The intermediate layer 130 is a layer that separates the reflective layer 120 and the second reflective layer 140, and pits are formed on the surface of the intermediate layer 130 in the same manner as the substrate by a 2P transfer method using an ultraviolet curable resin or the like. The thickness is, for example, 25 μm. Similar to the substrate 110, pits are formed on the surface of the intermediate layer 130 by a 2P transfer method using an ultraviolet curable resin. The thickness of the intermediate layer 130 is, for example, 25 μm.

  The cover layer 150 is made of a light transmissive ultraviolet curable resin, and has a thickness of, for example, 75 μm. A laser beam 160 emitted from a light source (not shown) is collected by the objective lens 170 and is applied to the reflective layer 120 or the second reflective layer 140 through the cover layer 150.

  An optical system having a large numerical aperture (NA) is used to read information recorded in the information recording section of this high-density recording type optical information recording medium. Therefore, a slight unevenness on the surface of the cover layer 150 or the presence of a few bubbles in the cover layer 150 leads to a significant deterioration of the reproduction signal. Therefore, the surface of the cover layer 150 covering the reflective layer 120 and the like is not inclined. It is formed in a smooth surface, and is configured in a form in which bubbles do not remain reliably in the cover layer 150.

Furthermore, as can be read accurately information in the reflective layer 120 or the like, (the thickness of the cover layer 150) a distance from the cover layer 150 surface to the second reflective layer 140 T ₂ is a conventional optical information recording medium ( For example, the thickness of the substrate on the information reading surface side in DVD) is very thin compared to the thickness of 0.6 mm, the wavelength of the laser beam 160 (405 nm), the numerical aperture of the objective lens 170 (0.85), and the refractive index of the cover layer 150. The film thickness difference between the inner periphery and the outer periphery of the cover layer 150 is 3 μm or less with a predetermined value (75 μm) corresponding to (about 1.5).

  FIG. 20 is a schematic view illustrating the schematic configuration of an optical information recording medium 100 manufacturing apparatus 200 according to the present invention. Referring to FIG. 20, an optical information recording medium 100 manufacturing apparatus 200 according to the present invention includes a rotary table 210, a substrate positioning unit 220, a rotary shaft 230, a drive motor 240, a center cap 25, and ultraviolet curing. This is a spin coating apparatus having a resin supply nozzle 260 and an ultraviolet (UV) irradiator 270.

The turntable 210 is placed so that a center hole 110a (not shown) of a substrate 110 (not shown) on which a reflective layer 120 made of a metal such as aluminum is laminated is fitted to the substrate positioning part 220, for example. The substrate 110 is supported from below. The rotary table 210 is connected to the drive motor 240 via the rotary shaft 230, and rotates at a high speed of, for example, about 30,000 rpm according to the rotation of the drive motor 240. Center cap 25 is movable in the Z-direction, Z _- by moving in a direction (not shown) center hole 110a of placed on the rotary table 210 a substrate 110 (not shown) It is arranged in a state that can be fitted.

  The ultraviolet curable resin supply nozzle 260 is a nozzle that is a material supply unit that supplies the ultraviolet curable resin, and is disposed above the rotary table 210 so as to be able to operate. The ultraviolet (UV) irradiator 270 is an irradiator for curing the ultraviolet curable resin, and is disposed above the rotary table 210 so as to be able to operate. The optical information recording medium 100 manufacturing apparatus 200 according to the present invention has a suction mechanism (not shown) including an intake passage and an intake hole, and holds and holds the substrate 110 placed on the rotary table 210 by suction. To do.

A method for manufacturing the optical information recording medium 100 according to the first embodiment of the present invention will be described with reference to FIGS. In the figure, the same components as those in FIGS. 19 and 20 are denoted by the same reference numerals, and the description thereof is omitted. First, using a stamper in which pits are formed, a plastic resin such as polycarbonate is injection-molded or pressure-molded to produce a substrate 110 on which pits are transferred. Next, aluminum or the like is laminated on the surface of the substrate 110 where the pits are formed by sputtering, vacuum deposition, or the like to form a reflective layer 120 that is a recording reflective film. Also, prepared with the intermediate layer 130 for forming the center cap 25A, and a large for forming the cover layer 150 center cap 25B of the radius _{R 1} than the intermediate layer 130 for forming the center cap 25A.

  Next, as shown in FIG. 21, the center hole 110a of the substrate 110 is placed on the rotary table 210 so as to be fitted to the substrate positioning portion 220, and is placed on the intake hole via an intake passage (not shown). A pressure is applied, and the substrate 110 placed on the turntable 210 is suction-fixed and held. Then, the fitting portion 25 c of the center cap 25 A for forming the intermediate layer 130 is fitted into the center hole 110 a of the substrate 110.

  Next, as shown in FIG. 22, a liquid ultraviolet curable resin 330, which is a material for forming the intermediate layer 130, is discharged onto the center cap 25A by an ultraviolet curable resin supply nozzle 260 (not shown), and then a drive motor. 240 (not shown) is operated, and the turntable 210 is rotated at a predetermined number of revolutions, so that a uniform intermediate layer 130 made of an ultraviolet curable resin 330 is formed on the reflective layer 120 as shown in FIG.

  Next, as shown in FIG. 24, the center cap 25A is removed, and as shown in FIG. 25, a light transmission stamper 340 having predetermined pits formed on the lower surface 340b is placed on the intermediate layer 130, as shown in FIG. In addition, while transferring the pits, ultraviolet rays 350 are irradiated from above the upper surface 340a of the stamper 340 by an ultraviolet ray (UV) irradiator 270 (not shown) to cure the ultraviolet curable resin 330, as shown in FIG. Then, the intermediate layer 130 having pit irregularities is formed by moving the stamper 340 upward.

Further, after the second reflective layer 140 is formed on the intermediate layer 130 by sputtering or the like so that a part of the light is transmitted through aluminum or the like, the substrate 110 is again formed as shown in FIG. the center hole 110a as fitted in the substrate positioning section 220 of, placed on the rotating table 210, a large radius _{R 1} than the center cap 25A, a fitting portion 25c of the cover layer 150 for forming the center cap 25B Fit into the center hole 110a of the substrate 110.

  Next, as shown in FIG. 29, the ultraviolet curable resin 330 is applied to the center of the substrate 110, and then the turntable 210 is rotated to form the ultraviolet curable resin 330 on the substrate as shown in FIG. A uniform cover layer 150 is formed. Next, as shown in FIG. 31, the center cap 25B is moved upward, and as shown in FIG. 32, an ultraviolet (UV) irradiator 270 (not shown) is formed from above the uniform cover layer 150 made of the ultraviolet curable resin 330. The optical information recording medium 100 according to Example 1 of the present invention is completed by irradiating the ultraviolet ray 350, curing the ultraviolet curable resin 330, and forming the cover layer 150.

  FIG. 33 is an enlarged view of the peripheral portion of the clamp portion 110b of the substrate 110 in FIG. 33, the same components as those in FIG. 30 are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 33, reference numeral 130a denotes a concavo-convex part formed on the clamp part 110b, and 130b and 150b denote convex parts formed on the periphery of the clamp part 110b (ends of the center caps 25A and 25B).

As shown in FIG. 33, the convex portion 130b in the peripheral portion (end portion of the center cap 25A) of the clamp portion 110b formed when the intermediate layer 130 is formed has a radius R ₁ than the center cap 25A for forming the intermediate layer 130. By covering with the large cover layer 150 forming center cap 25B, the UV curable resin 330 spreads uniformly without being affected by the convex portion 130b formed in the peripheral portion of the clamp portion 110b (the end portion of the center cap 25A). Therefore, in the cover layer 150, the incidence rate of the radial linear defects 36 as shown in FIG. 18 is greatly reduced.

  FIG. 34 is a plan view of the optical information recording medium 100 shown in FIG. 33 as viewed from the cover layer 150 side. As shown in FIG. 33, the optical information recording medium 100 manufactured by the method according to the first embodiment is different in the radial position where the formation of the intermediate layer 130 and the cover layer 150 is started in the peripheral part of the clamp part 110b. Since the radial position at which the formation of the layer 150 is started is on the outer peripheral side with respect to the radial position at which the formation of the intermediate layer 130 is started, the radial position at the periphery of the radial position at which the formation of the intermediate layer 130 and the cover layer 150 is started. A step as shown in FIG. 33 is formed. Therefore, when the optical information recording medium 100 in which the step as shown in FIG. 33 is formed is viewed in plan from the cover layer 150 side, only the intermediate layer 130 is located in a region close to the outside of the clamp part 110b as shown in FIG. An annular region consisting of can be confirmed.

  In the case of an optical information recording medium of three or more layers in which a plurality of information layers and an intermediate layer 130 for separating the plurality of information layers are alternately stacked on the substrate 110, and finally a cover layer 150 is stacked. The radial position at which the formation of the intermediate layer 130 first laminated on the substrate 110 is started is on the inner peripheral side with respect to the radial position at which the formation of the intermediate layer 130 laminated later is started. The radial position where the formation is started is on the outer peripheral side with respect to the radial position where the formation of the intermediate layer 130 to be finally stacked is started.

According to the first embodiment of the present invention, the radius _{R 1} of the cover layer 150 for forming the center cap 25B, and to be greater than the radius _{R 1} of the intermediate layer 130 formed for the center cap 25A, when forming the cover layer 150, the cover The center cap 25B for forming the layer 150 covers the convex portion 130b formed on the periphery of the clamp portion 110b (the end portion of the center cap 25A) when the intermediate layer 130 is formed. Therefore, the ultraviolet curable resin 330 spreads uniformly without being affected by the convex portion 130b formed in the peripheral portion of the clamp portion 110b (the end portion of the center cap 25A), and in the cover layer 150, as shown in FIG. The occurrence rate of the radial linear defect 36 is greatly reduced, and deterioration of optical characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

<Example 2>
In Example 2, the intermediate layer 130 forming the center cap 25C for and for forming the cover layer 150 center cap 25D, are prepared two different types of the center caps 25 having the radius _{R 1,} the radius of the intermediate layer 130 forming the center cap 25C for R ₁ was set to 9.5 mm, and the radius R ₁ of the center cap 25D for forming the cover layer 150 was shaken from 9 mm to 14 mm to form the cover layer 150, and the incidence rate of the radial linear defects 36 was determined. Specifically, n optical information recording media are manufactured, and the optical information recording medium in which the radial linear defects 36 are generated is regarded as defective (NG), and the incidence rate of the radial linear defects 36 = (NG). Number / n) × 100 (%).

Figure 35 is a diagram illustrating the relationship between the incidence of radius R ₁ and the radial linear defects 36 of the cover layer 150 for forming the center cap 25D. As shown in FIG. 35, the radius R ₁ of the center cap 25D for forming the cover layer 150 becomes a radial line abruptly from the point where the radius R ₁ of the center cap 25C for forming the intermediate layer 130 is larger by 0.25 mm or more. When the occurrence rate of the line defects 36 began to decrease and became larger by 0.5 mm or more, almost no radial line defects 36 were observed.

According to the second embodiment of the present invention, the radius R ₁ of the center cap 25D for forming the cover layer 150 is 0.25 mm or more, preferably 0.5 mm or more larger than the radius R ₁ of the center cap 25C for forming the intermediate layer 130. Thus, when the cover layer 150 is formed, the center cap 25D for forming the cover layer 150 covers the convex portion 130b formed on the peripheral portion (the end portion of the center cap 25C) of the clamp portion 110b when the intermediate layer 130 is formed. . Therefore, the ultraviolet curable resin 330 spreads uniformly without being affected by the convex portion 130b formed in the peripheral portion of the clamp portion 110b (the end portion of the center cap 25C), and in the cover layer 150, as shown in FIG. The occurrence rate of the radial linear defect 36 is greatly reduced, and deterioration of optical characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

In the case where three or more intermediate layers and cover layers are formed using the center cap 25 of the present invention, the radius R ₁ of the center cap 25 for the intermediate layer to be laminated _first is the smallest, and the radius R gradually increases from there. _It is important that the middle layer is overlapped using _one large center cap 25 so that the radius R ₁ of the center cap 25 for the cover layer to be finally formed becomes the largest. In this way, the center cap 25 having the radius R ₁ optimized for each layer escapes the convex portion of the peripheral portion (end portion of the center cap 25) of the clamp portion 110b formed when forming the intermediate layer. In addition, since it is not affected by the convex portions at the time of forming each intermediate layer, the occurrence rate of radial linear defects 36 can be greatly reduced even in an optical information recording medium having three or more layers. And / or deterioration of optical characteristics such as jitter and error rate during recording can be prevented.

<Example 3>
In Example 3, the radius _{R 1} of the intermediate layer 130 formed for the center cap 25C, the relationship between the end face 25e and a slight penetration incidence of the liquid UV curing resin 330 into the gap _{T 1} of the substrate 110 of the center cap 25C to confirm the, intermediate layer 130 is formed by shaking the radius _{R 1} of the intermediate layer 130 forming the center cap 25C for from 7.5mm to 11 mm, was determined penetration incidence of the ultraviolet curable resin 330. Specifically, n optical information recording media are manufactured, and the optical information recording medium in which the ultraviolet curable resin 330 has penetrated even a little is regarded as defective (NG), and the incidence rate of the ultraviolet curable resin 330 infiltration = (NG) Number / n) × 100 (%). The radius R ₁ of the center cap 25D for forming the cover layer 150 was always set to a value 1 mm larger than the radius R ₁ of the center cap 25C for forming the intermediate layer 130.

Figure 36 is a diagram illustrating the relationship between the penetration incidence of radius R ₁ and the ultraviolet curing resin 330 for forming the intermediate layer 130 center cap 25C. As shown in FIG. 36, when the radius R ₁ of the center cap 25C for forming the intermediate layer 130 is smaller than 8.5 mm, the liquid ultraviolet ray into the slight gap T ₁ between the end face 25e of the center cap 25C and the substrate 110 is obtained. The incidence of penetration of the cured resin 330 increased rapidly.

According to the third embodiment of the present invention, by setting the radius R ₁ of the center cap 25C for forming the intermediate layer 130 to 8.5 mm or more, the slight gap T ₁ between the end face 25e of the center cap 25C and the substrate 110 is obtained. The penetration rate of the liquid UV curable resin 330 can be greatly reduced, and the optical information recording medium is mounted on the information recording / reproducing apparatus due to the influence of the uneven portion 130a formed on the clamp portion 110b of the substrate 110. In this case, since the degree of mounting at a tilt is reduced, deterioration of tilt characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

In the case where three or more intermediate layers and cover layers are formed using the center cap 25 of the present invention, the radius R ₁ of the intermediate layer forming center cap 25 to be first laminated is set to 8.5 mm or more. gradually superimposed intermediate layer with a large center cap 25 having a radius R _1, by such a radius R ₁ of the center cap 25 for cover layer formed last is maximized, the center cap 25 from it is possible to significantly reduce the slight penetration incidence of the liquid UV curing resin 330 into the gap T ₁ of the the end face 25e and the substrate 110, the influence of the concave and convex portion 130a formed on the clamp part 110b of the substrate 110 Therefore, when the optical information recording medium is attached to the information recording / reproducing apparatus, the degree of being inclined is reduced. Deterioration of tilt characteristics such as jitter and error rate during recording can be prevented.

<Example 4>
Example 4 shows an example in which a center cap having a shape different from that used in Examples 1 to 3 is used. FIG. 37 is a diagram illustrating the center cap 26 according to the present invention used when forming a layer on a substrate by spin coating. 37 (a) and 37 (d) are sectional views, FIG. 37 (b) is a front view, and FIG. 37 (c) is a bottom view.

  The center cap 26 shown in FIG. 37 is provided concentrically with the fitting portion 26c fitted into the center hole 110a of the substrate 110 and the fitting portion 26c, and the fitting portion 26c is fitted into the center hole 110a of the substrate 110. When combined, an umbrella-shaped portion 26b having an end face 26e formed of an annular plane that is parallel to the substrate 110 and has a larger diameter than the fitting portion 26c, and an umbrella-shaped portion on the upper portion of the umbrella-shaped portion 26b 26b and a cylindrical projection 26a provided concentrically.

  Further, the end surface 26e, which is a portion that comes into contact with the substrate 110, is an annular flat surface that is flat on the entire surface. As shown in FIG. 37 (c), the end face 26e is provided so as not to contact the bottom-view fitting part 26c. As shown in FIG. 37 (b), the fitting part 26c projects from the front-view end face 26e. As shown in FIG. 37 (d), when the fitting portion 26c is fitted into the center hole 110a of the substrate 110, the end face 26e is brought into contact with the upper surface of the substrate 110, and the inner surface of the umbrella-shaped portion 26b and the substrate A space portion 26 d is formed between the space 110 and 110.

In addition, when the end surface 26e of the center cap 26 abuts on the substrate 110, a very slight gap is generated. In Figure 37, _{R 2} is the radius of the cone-shaped part 26b of the center cap 26, _{W 2} is the width of the end surface 26e, H denotes the maximum height of the space 26 d.

  As described above, the center cap 26 according to the fourth embodiment of the present invention has a structure in which the space 26d is formed so that only the end surface 26e formed on the peripheral edge of the center cap 26 contacts the upper surface of the substrate 110. Compared with the setter cap 25 shown in FIG. 3, the area of the portion in contact with the upper surface of the substrate 110 is significantly reduced.

  In the center cap 26 according to the fourth embodiment of the present invention, the space 26d is formed so that only the end surface 26e formed at the peripheral edge of the center cap 26 is in contact with the upper surface of the substrate 110. Therefore, the umbrella-shaped portion 26b does not necessarily have a conical shape, and the height of the outer surface of the umbrella-shaped portion 26b of the center cap 26 gradually decreases from the center of the umbrella-shaped portion 26b toward the outer periphery. Thus, any shape may be used as long as the shape has an inclination from the center to the outer periphery.

  In addition, as illustrated in FIG. 37, the space portion 26 d preferably has a shape in which the height gradually decreases from the center of the umbrella-shaped portion 26 b toward the outer periphery, but only the end surface 26 e is formed on the substrate 110. Any shape may be used as long as a space is provided so as to contact the upper surface.

In Example 4, the center cap 26A for forming the intermediate layer 130, than the intermediate layer 130 for forming the center cap 26A were prepared and large for forming the cover layer 150 center cap 26B of the radius _{R 2.} Then, the optical information recording medium 100 was manufactured using the setter caps 26A and 26B.

Specifically, the center cap 26A for forming the intermediate layer 130 has a radius R ₂ = 7.5 mm of the umbrella-shaped portion 26b, a width W ₂ = 0.1 mm of the end face 26e, and a maximum height H = 0 of the space portion 26d. .1 mm. The center cap 26B for forming the cover layer 150 has the radius R ₂ = 11 mm of the umbrella-shaped portion 26b, the width W ₂ of the end face 26e = 0.1 mm, and the maximum height H of the space portion 26d = 0.1 mm.

  A method for manufacturing the optical information recording medium 100 according to Embodiment 4 of the present invention will be described with reference to FIGS. In FIG. 19, parts that are the same as those shown in FIGS. 19 to 34 are given the same reference numerals, and descriptions thereof may be omitted. First, using a stamper in which pits are formed, a plastic resin such as polycarbonate is injection-molded or pressure-molded to produce a substrate 110 on which pits are transferred. Next, aluminum or the like is laminated on the surface of the substrate 110 where the pits are formed by sputtering, vacuum deposition, or the like to form a reflective layer 120 that is a recording reflective film.

  Next, as shown in FIG. 38, the center hole 110a of the substrate 110 is placed on the rotary table 210 so as to fit the substrate positioning portion 220, and is placed on the intake hole via an intake passage (not shown). A pressure is applied, and the substrate 110 placed on the turntable 210 is suction-fixed and held. Then, the fitting portion 26c of the center cap 26A is fitted into the center hole 110a of the substrate 110.

  Next, the same processes as in FIGS. 22 to 27 are performed. That is, a liquid ultraviolet curable resin 330 that is a material for forming the intermediate layer 130 is discharged onto the center cap 26A by an ultraviolet curable resin supply nozzle 260 (not shown). Thereafter, the drive motor 240 (not shown) is operated, and the turntable 210 is rotated at a predetermined number of revolutions to form the uniform intermediate layer 130 made of the ultraviolet curable resin 330 on the reflective layer 120. Next, the center cap 26A is removed, and a light-transmitting stamper 340 having predetermined pits formed on the lower surface 340b is placed on the intermediate layer 130. Then, while transferring the pits, ultraviolet rays 350 are irradiated from above the upper surface 340a of the stamper 340 by an ultraviolet (UV) irradiator 270 (not shown) to cure the ultraviolet curable resin 330. Thereafter, the stamper 340 is moved upward to form the intermediate layer 130 with pit irregularities.

Further, after the second reflective layer 140 is formed on the intermediate layer 130 by sputtering or the like so as to partially transmit light such as aluminum, the substrate 110 is again formed as shown in FIG. the center hole 110a as fitted in the substrate positioning section 220 of, placed on the rotary table 210, the substrate fitting portions 26c of the large center cap 26B of the radius _{R 2} of the cone-shaped part 26b than the center cap 26A Fit into the 110 center hole 110a.

  Next, the same processes as in FIGS. 29 to 30 are performed. That is, after the ultraviolet curable resin 330 is applied to the center of the substrate 110, the turntable 210 is rotated to form the uniform cover layer 150 made of the ultraviolet curable resin 330 on the substrate 110. Next, as shown in FIG. 40, the center cap 26B is moved upward, and as shown in FIG. 41, an ultraviolet (UV) irradiator 270 (not shown) is formed from above the uniform cover layer 150 made of the ultraviolet curable resin 330. The optical information recording medium 100 according to Example 4 of the present invention is completed by irradiating the ultraviolet ray 350, curing the ultraviolet curable resin 330, and forming the cover layer 150.

Thus, in Example 4, in FIG. 37, the radius R ₂ of the umbrella-shaped portion 26b = 7.5 mm, the width W ₂ of the end face 26e = 0.1 mm, and the maximum height H = 0.1 mm of the space portion 26d. 37, the center layer 26A for forming the intermediate layer 130, and in FIG. 37, the radius R ₂ of the umbrella-shaped portion 26b = 11 mm, the width W ₂ of the end face 26e = 0.1 mm, and the maximum height H of the space portion 26d = 0.1 mm. When the optical information recording medium 100 is manufactured using the center cap 26B for forming the cover layer 150, the uneven portion formed on the clamp portion 110b of the substrate 110 and the peripheral portion of the clamp portion 110b (the center caps 26A and 26B) are formed. As shown in FIGS. 42 and 43, the maximum height of the convex portion formed at the end portion was significantly lower than that in FIGS. 16 and 17.

  42 is an enlarged view of the peripheral portion of the clamp portion 110b of the substrate 110 in FIG. 40, and FIG. 43 is an enlarged view of the peripheral portion of the clamp portion 110b of the substrate 110 in FIG. 42 and 43, parts that are the same as those in FIGS. 40 and 41 are given the same reference numerals, and descriptions thereof will be omitted. 42 and 43, reference numeral 130a denotes an uneven portion formed on the clamp portion 110b, and 130b and 150b denote convex portions formed on the periphery of the clamp portion 110b (end portions of the center caps 26A and 26B). .

  When the intermediate layer 130 is formed, if the liquid ultraviolet curable resin 330 is dropped on the center cap 26A, the liquid ultraviolet curable resin 330 penetrates only into the lower portion of the end face 26e of the center cap 26A due to capillary action, and is then formed on the clamp portion 110b. The uneven part 130a is formed, and the convex part 130b may be formed in the peripheral part of the clamp part 110b (the end part of the center cap 26A), but the uneven part when the uneven part 130a and the convex part 130b are formed. The maximum heights of 130a and convex part 130b were significantly lower than those in FIGS.

  This is because, as shown in FIG. 37, the center cap 26A according to the present invention has a space portion 26d between the inner surface of the umbrella-shaped portion 26b of the center cap 26A and the substrate 110. That is, this is because a large gap is formed between the center cap 26A and the substrate 110, and only the end surface 26e formed at the peripheral edge of the center cap 26A is in contact with the upper surface of the substrate 110. As a result, the area of the portion in contact with the upper surface of the substrate 110 is greatly reduced as compared with the center cap 25, and even if the liquid ultraviolet curable resin 330 is dropped on the center cap 26A, as shown in FIGS. In addition, the amount of the liquid UV curable resin 330 that permeates the center cap 26A due to the capillary phenomenon is significantly reduced compared to the conventional case.

  Further, when forming the cover layer 150, the radius (= 11 mm) of the umbrella-shaped portion 26b of the center cap 26B for forming the cover layer 150 is set to the radius (= 7. As a result, the incidence rate of the radial linear defects 36 as shown in FIG. 18 was greatly reduced.

As shown in FIG. 42, the convex portion 130b of the periphery of the clamp portion 110b (the end portion of the center cap 26A) formed slightly during the formation of the intermediate layer 130 is made more than the center cap 26A for forming the intermediate layer 130. by covering a large for forming the cover layer 150 center cap 26B of the radius _{R 2} of the cone-shaped part 26b, the ultraviolet curing resin 330, the convex portion 130b formed in the peripheral portion of the clamp portion 110b (the end portion of the center cap 26A) It is because it spreads uniformly without being influenced by.

  As shown in FIGS. 42 and 43, the optical information recording medium 100 manufactured by the method according to Example 4 has a radial position where the formation of the intermediate layer 130 and the cover layer 150 is started at the periphery of the clamp portion 110b. In contrast, since the radial position at which the formation of the cover layer 150 is started is on the outer peripheral side with respect to the radial position at which the formation of the intermediate layer 130 is started, the radial position at which the formation of the intermediate layer 130 and the cover layer 150 is started. Steps as shown in FIGS. 42 and 43 are formed in the peripheral portion. Therefore, when the optical information recording medium 100 in which the steps as shown in FIGS. 42 and 43 are formed is viewed in plan from the cover layer 150 side, it is close to the outside of the clamp portion 110b as in FIG. An annular region consisting only of the intermediate layer 130 can be confirmed in the region to be processed.

  In the case of an optical information recording medium of three or more layers in which a plurality of information layers and an intermediate layer 130 for separating the plurality of information layers are alternately stacked on the substrate 110, and finally a cover layer 150 is stacked. The radial position at which the formation of the intermediate layer 130 first laminated on the substrate 110 is started is on the inner peripheral side with respect to the radial position at which the formation of the intermediate layer 130 laminated later is started. The radial position where the formation is started is on the outer peripheral side with respect to the radial position where the formation of the intermediate layer 130 to be finally stacked is started.

  According to the fourth embodiment of the present invention, by providing the space portion 26d between the inner surface of the umbrella-shaped portion 26b of the center cap 26A and the substrate 110, a large gap is formed between the center cap 26A and the substrate 110, Since only the end surface 26e formed on the peripheral edge of the center cap 26A is in contact with the upper surface of the substrate 110, the penetration of the liquid ultraviolet curable resin 330 due to capillary action is greatly reduced. The maximum height of the concavo-convex part 130a formed on the part 110b can be significantly reduced, and the degree of being inclined when the optical information recording medium 100 is attached to the information recording / reproducing apparatus is reduced. Further, it is possible to prevent deterioration of tilt characteristics such as jitter and error rate during reproduction and / or recording.

Further, the radius R ₂ (= 11 mm) of the umbrella-shaped portion 26b of the center cap 26B for forming the cover layer 150 is larger than the radius R ₂ (= 7.5 mm) of the umbrella-shaped portion 26b of the center cap 26A for forming the intermediate layer 130. By forming the cover layer 150, the center layer 26B for forming the cover layer 150 is slightly formed on the periphery of the clamp portion 110b (the end of the center cap 26A) when the intermediate layer 130 is formed. Cover 130b. Therefore, the ultraviolet curable resin 330 spreads uniformly without being affected by the convex portion 130b formed in the peripheral portion of the clamp portion 110b (the end portion of the center cap 26A), and the cover layer 150 has a radial shape as shown in FIG. The occurrence rate of the linear defect 36 is greatly reduced, and deterioration of optical characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

In Example 4, the radius _{R 2} of the cone-shaped part 26b of the cover layer 150 for forming the center cap 26B, was greater than the radius _{R 2} of the cone-shaped part 26b of the intermediate layer 130 formed for the center cap 26A, the cover If the radius _{R 2} of the cone-shaped part 26b of the layer 150 for forming the center cap 26B, be the same as the radius _{R 2} of the cone-shaped part 26b of the intermediate layer 130 formed for the center cap 26A, which uses a conventional center cap 25 Compared to the above, in the cover layer 150, it is possible to reduce the occurrence rate of the radial linear defects 36 as shown in FIG. 18, and the optical characteristics such as jitter and error rate during reproduction and / or recording are deteriorated. Can be prevented.

  This is because a space 26d is provided between the inner surface of the umbrella-shaped portion 26b of the center caps 26A and 26B and the substrate 110, thereby forming a large gap between the center caps 26A and 26B and the substrate 110. And the end face 26e formed on the peripheral edge of the edge 26B, the penetration of the liquid UV curable resin 330 due to capillary action is greatly reduced by the structure in contact with the upper surface of the substrate 110. This is because not only the maximum height of the concavo-convex part 130a formed on 110b but also the maximum height of the convex part 130b formed on the peripheral part of the clamp part 110b (the end part of the center cap 26A) is significantly reduced.

<Example 5>
In Example 5, and 11mm radius _{R 2} of the cone-shaped part 26b of the center cap 26 shown in FIG. 37, the width _{W 2} of the end surface 26e and 2 mm, 0.3 mm and the maximum height H of the space 26d from 0.01mm The cover layer 150 was formed by shaking until the maximum height of the uneven portion 130a formed on the clamp portion 110b was obtained. FIG. 44 is a diagram illustrating the relationship between the maximum height H of the space portion 26d of the center cap 26 and the maximum height of the uneven portion 130a formed on the clamp portion 110b. In addition, the measurement of the height of an uneven part was performed using the surface shape measuring apparatus deck tack (made by Sloan).

  As shown in FIG. 44, as the maximum height H of the space portion 26d of the center cap 26 according to the present invention used when forming the cover layer 150 becomes lower than 0.05 mm, it is formed on the clamp portion 110b. It has been confirmed that the maximum height of the uneven portion 130a increases.

  According to the fifth embodiment of the present invention, if the maximum height H of the space portion 26d of the center cap 26 according to the present invention is 0.05 mm or more, the penetration of the liquid ultraviolet curable resin 330 due to the capillary phenomenon is greatly reduced. To do. As a result, the maximum height of the concavo-convex part 130a formed on the clamp part 110b of the substrate 110 can be significantly reduced, and the optical information recording medium is inclined when it is attached to the information recording / reproducing apparatus. The degree of tilting is reduced, and deterioration of tilt characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

<Example 6>
In Example 6, prepared two different types of the center caps 26 having the radius _{R 2} of the cone-shaped part 26b of the center for forming the intermediate layer 130 cap 26C and the cover layer 150 for forming the center cap 26D, the intermediate layer 130 for forming the center cap The cover layer 150 is formed by setting the radius R ₂ of the umbrella-shaped portion 26b of 26C to 9 mm, the width W ₂ of the end face 26e to 2 mm, and the maximum height H of the space portion 26d from 0.01 mm to 0.3 mm to form the cover layer 150. The occurrence rate of the linear defect 36 was determined.

Specifically, n optical information recording media are manufactured, and the optical information recording medium in which the radial linear defects 36 are generated is regarded as defective (NG), and the incidence rate of the radial linear defects 36 = (NG). Number / n) × 100 (%). A cover layer 150 is formed for the center cap 26D has a radius _{R 2} of the cone-shaped part 26b 11 mm, the width _{W 2} of the end surface 26e 2 mm, the maximum height H of the space 26d and 0.05 mm.

  FIG. 45 is a diagram illustrating the relationship between the maximum height H of the space portion 26d and the incidence rate of the radial linear defects 36. As shown in FIG. 45, when the cover layer 150 is formed as the maximum height H of the space portion 26d of the center cap 26C according to the present invention used when forming the intermediate layer 130 becomes lower than 0.05 mm. It was confirmed that the incidence rate of the radial linear defects 36 that can be increased is increased.

  According to Embodiment 6 of the present invention, if the maximum height H of the space portion 26d of the center cap 26C according to the present invention used when forming the intermediate layer 130 is 0.05 mm or more, the liquid state due to capillary action The penetration of the UV curable resin 330 is greatly reduced. As a result, not only the maximum height of the concavo-convex portion 130a formed on the clamp portion 110b of the substrate 110 but also the maximum height of the convex portion 130b formed on the peripheral portion of the clamp portion 110b (the end portion of the center cap 26c). Significantly lower. Therefore, the incidence rate of the radial linear defects 36 formed when the cover layer 150 is formed can be reduced, and the high-quality cover layer 150 that is not affected by the intermediate layer 130 can be formed. Deterioration of optical characteristics such as jitter and error rate during recording can be prevented.

In the case of forming with a center cap 26 of the present invention the three layers or more intermediate layers and cover layers, the radius R ₂ is the smallest of the cone-shaped part 26b of the center cap 26 for the intermediate layer initially laminated, there go superposed intermediate layer, the radius R ₂ of the cone-shaped part 26b of the center cap 26 for cover layer formed last is the largest with a large center cap 26 having a radius R ₂ gradually umbrella portion 26b from It is important to do so. In this way, the edge of the peripheral portion (the center cap 26 slightly can clamp portion 110b when the center cap 26 having a radius R ₂ is an intermediate layer formed of cone-shaped part 26b optimized for each layer ), And is not affected by the projections when forming the intermediate layers, so that the incidence of radial linear defects 36 is greatly reduced even in an optical information recording medium having three or more layers. It is possible to prevent the deterioration of optical characteristics such as jitter and error rate during reproduction and / or recording.

<Example 7>
In Example 7, 3 mm radius _{R 2} of the cone-shaped part 26b of the center cap 26 shown in FIG. 37 11 mm, the maximum height H of the space 26d and 0.05 mm, the width _{W 2} of the end surface 26e from 0.1mm The cover layer 150 was formed by shaking until the maximum height of the uneven portion 130a formed on the clamp portion 110b was obtained. In addition, the measurement of the height of an uneven part was performed using the surface shape measuring apparatus deck tack (made by Sloan).

Figure 46 is a diagram illustrating the relationship between the maximum height of the concave and convex portion 130a formed on the width _{W 2} and the clamp portion 110b of the end surface 26e of the center cap 26. As shown in FIG. 46, as the width W2 of the end face 26e of the center cap 26 according to the present invention used when forming the cover layer 150 becomes wider than ₂ mm, the uneven portion 130a formed on the clamp portion 110b. It was confirmed that the maximum height of was high.

According to the seventh embodiment of the present invention, the width W ₂ of the end surface 26e of the center cap 26 according to the present invention is equal to 2mm or less, penetration of the liquid UV curing resin 330 due to capillary action is much reduced. As a result, the maximum height of the concavo-convex part 130a formed on the clamp part 110b of the substrate 110 can be significantly reduced, and the optical information recording medium is inclined when it is attached to the information recording / reproducing apparatus. The degree of tilting is reduced, and deterioration of tilt characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

<Example 8>
In Example 8, prepared two different types of the center caps 26 having the radius _{R 2} of the cone-shaped part 26b of the center for forming the intermediate layer 130 cap 26C and the cover layer 150 for forming the center cap 26D, the intermediate layer 130 for forming the center cap 26C of the radius _{R 2} of the cone-shaped part 26b 9 mm, and 0.05mm maximum height H of the space 26 d, the width _{W 2} of the end surface 26e waving from 0.1mm to 3mm to form a cover layer 150, radially The occurrence rate of the linear defect 36 was determined. A cover layer 150 is formed for the center cap 26d has a radius _{R 2} of the cone-shaped part 26b 11 mm, the width _{W 2} of the end surface 26e 2 mm, the maximum height H of the space 26d and 0.05 mm.

Figure 47 is a diagram illustrating the relationship between the incidence of width W ₂ and the radial linear defects 36 of the end surface 26e of the center cap 26C. 47, as the width W2 of the end face 26e of the center cap 26C according to the present invention used when forming the intermediate layer 130 becomes wider than ₂ mm, the radial shape formed when the cover layer 150 is formed. It was confirmed that the incidence rate of the linear defects 36 is increased.

According to the eighth embodiment of the present invention, if the width W ₂ of the end surface 26e of the center cap 26c according to the present invention for use in forming the intermediate layer 130 is 2mm or less, the liquid by capillary action ultraviolet curing resin 330 The soaking of water is greatly reduced. As a result, not only the maximum height of the concavo-convex portion 130a formed on the clamp portion 110b of the substrate 110 but also the maximum height of the convex portion 130b formed on the peripheral portion of the clamp portion 110b (the end portion of the center cap 26c). Significantly lower. Therefore, the incidence rate of the radial linear defects 36 that can be formed when the cover layer 150 is formed is reduced, and the high-quality cover layer 150 that is not affected by the intermediate layer 130 can be formed. Deterioration of optical characteristics such as jitter and error rate during recording can be prevented.

In the case of forming with a center cap 26 of the present invention the three layers or more intermediate layers and cover layers, the radius R ₂ is the smallest of the cone-shaped part 26b of the center cap 26 for the intermediate layer initially laminated, there go superposed intermediate layer, the radius R ₂ of the cone-shaped part 26b of the center cap 26 for cover layer formed last is the largest with a large center cap 26 having a radius R ₂ gradually umbrella portion 26b from It is important to do so. In this way, the edge of the peripheral portion (the center cap 26 slightly can clamp portion 110b when the center cap 26 having a radius R ₂ is an intermediate layer formed of cone-shaped part 26b optimized for each layer ) Can be escaped and is not affected by the protrusions when forming each intermediate layer, so that radial linear defects can be greatly reduced even in an optical information recording medium having three or more layers. Thus, deterioration of optical characteristics such as jitter and error rate during reproduction and / or recording can be prevented.

<Example 9>
Example 9 shows an example in which a center cap having a shape different from the center cap 25 shown in FIG. 3 and the center cap 26 shown in FIG. 37 is used. FIG. 48 is a diagram illustrating a center cap 27 according to the present invention used when forming a layer on a substrate by spin coating. FIG. 48A is a front view, and FIG. 48B is a plan view.

  The center cap 27 shown in FIG. 48 is provided concentrically with the fitting portion 27c fitted into the center hole 110a of the substrate 110 and the fitting portion 27c, and the fitting portion 27c is fitted into the center hole 110a of the substrate 110. When combined, an umbrella-shaped portion 27b having an end surface 27e made of an annular plane that is parallel to the substrate 110 and has a larger diameter than the fitting portion 27c, and an umbrella-shaped portion on the upper portion of the umbrella-shaped portion 27b 27b and a cylindrical protrusion 27a provided concentrically.

  The center cap 27 is provided with an outside air introduction hole 27x. The outside air introduction hole 27x is provided in the Z direction, is provided in the X direction in the fitting portion 27c, and is provided in the fitting portion 27c through the fitting portion 27c through a vertical hole that penetrates the upper surface of the protruding portion 27a and the lower surface of the fitting portion 27c. It is the structure where the horizontal hole which communicates in the fitting part 27c. That is, the outside air introduction hole 27x has four openings, the first opening is on the upper surface of the protrusion 27a, the second opening is on the lower surface of the fitting portion 27c, and the third and fourth openings. Are provided at opposite positions on the side surface of the fitting portion 27c.

  As described above, the substrate 110 is placed on the rotary table 210 so that the center hole 110a is fitted to the substrate positioning part 220, and a negative pressure is applied to the intake hole via the intake passage (not shown). Then, the substrate 110 placed on the rotary table 210 is suction-fixed and held. Then, the fitting portion 25 c of the center cap 25 is fitted into the center hole 110 a of the substrate 110.

  FIG. 49 is a diagram illustrating a state in which the fitting portion 25 c of the center cap 25 is fitted into the center hole 110 a of the substrate 110. The negative pressure applied to hold the substrate 110 by suction and fixation also affects the gap 29a between the center cap 25 and the substrate 110 shown in FIG. 49, and the gap 29a may also become a negative pressure. When the gap 29a becomes negative pressure, when the UV curable resin 330 is applied onto the center cap 25, the UV curable resin 330 penetrates into the gap 29a, and a convex portion is formed around the clamp portion of the substrate. Will be.

  FIG. 50 is a diagram illustrating a state in which the fitting portion 27 c of the center cap 27 is fitted into the center hole 110 a of the substrate 110. As shown in FIG. 50, when the center cap 27 is used, since the outside air flows into the gap 29a from the outside air introduction hole 27x, the gap 29a can be prevented from becoming a negative pressure.

  According to the ninth embodiment of the present invention, when the intermediate layer 130 or the cover layer 150 is formed, by using the center cap 27 having the outside air introduction hole 27x, the gap 29a between the center cap 27 and the substrate 110 is negative pressure. Can be prevented. As a result, when the ultraviolet curable resin 330 is applied onto the center cap 27, the negative pressure applied to hold the substrate 110 by suction and fixation does not promote the penetration of the ultraviolet curable resin 330 into the gap 29a. It can prevent that a convex part is formed in the peripheral part of this clamp part.

  In the ninth embodiment, the center cap 27 provided with the outside air introduction hole 27x in the center cap 25 has been described. However, the center cap 26 can be similarly provided with the outside air introduction hole, and the same effect can be obtained.

<Example 10>
Example 10 shows an example in which the center cap 27 shown in FIG. 48 is modified. FIG. 51 is a diagram illustrating a center cap 28 according to the present invention used when forming a layer on a substrate by spin coating. FIG. 51A is a front view, and FIG. 51B is a plan view. In FIG. 51 (b), the broken arrow indicates the direction in which the center cap 28 rotates.

  The center cap 28 shown in FIG. 51 is provided concentrically with the fitting portion 28c fitted into the center hole 110a of the substrate 110 and the fitting portion 28c, and the fitting portion 28c is fitted into the center hole 110a of the substrate 110. When combined, an umbrella-shaped portion 28b having an end face 28e formed of an annular plane that is parallel to the substrate 110 and has a larger diameter than the fitting portion 28c, and an umbrella-shaped portion on the upper portion of the umbrella-shaped portion 28b 28b and a cylindrical protrusion 28a provided concentrically.

  The center cap 28 is provided with an outside air introduction hole 28x and an outside air introduction member 28y. The outside air introduction hole 28x is provided in the Z direction, and is a vertical hole that penetrates the upper surface of the protrusion 28a and the lower surface of the fitting portion 28c, and a horizontal hole that is provided in the X direction and extends through the protrusion 28a. And a lateral hole provided in the fitting portion 28c in the X direction and penetrating through the fitting portion 28c is communicated within the projection portion 28a and the fitting portion 28c.

  That is, the outside air introduction hole 28x has six openings, the first opening is on the upper surface of the protrusion 28a, the second opening is on the lower surface of the fitting portion 28c, and the third and fourth openings. The portion is provided at a position where the side surface of the projection 28a faces, and the fifth and sixth openings are provided at a position where the side surface of the fitting portion 28c faces.

  An outside air introduction member 28y that introduces outside air into the outside air introduction hole 28x when the center cap 28 rotates is provided in the vicinity of the third and fourth openings provided at positions facing the side surfaces of the protrusion 28a. It has been. The outside air introduction member 28y can be provided by, for example, fixing metal, plastic, or the like to the center cap 28. The outside air introduction member 28y may be molded integrally with the center cap 28.

  By providing the outside air introduction member 28y, for example, when the center cap 28 is rotated in the direction indicated by the broken arrow in FIG. Outside air can be efficiently introduced into the outside air introduction hole 28x from the third and fourth openings provided at the opposing positions.

  According to the tenth embodiment of the present invention, when the intermediate layer 130 or the cover layer 150 is formed, the center cap 28 having the outside air introduction hole 28x and the outside air introduction member 28y is used, as in the ninth embodiment. The gap 29a between the cap 28 and the substrate 110 can be prevented from becoming a negative pressure. As a result, when the ultraviolet curable resin 330 is applied on the center cap 28, the negative pressure that acts to adsorb and hold the substrate 110 does not promote the penetration of the ultraviolet curable resin 330 into the gap 29a. It can prevent that a convex part is formed in the peripheral part of this clamp part. Furthermore, by providing the outside air introduction member 28y in the vicinity of the third and fourth openings of the center cap 28, outside air can be efficiently introduced into the outside air introduction hole 28x.

  In the tenth embodiment, the center cap 28 provided with the outside air introduction member 28y in the center cap 27 has been described. However, the center cap 26 can be similarly provided with an outside air introduction hole and an outside air introduction member. There is an effect.

<Comparative example 1>
In Comparative Example 1, the difference between the inner and outer peripheral thickness profiles when the cover layer 150 was formed using the center cap 26 according to the present invention and when the cover layer 150 was formed without using the center cap was shown. FIG. 52 is a diagram illustrating the relationship between the radial position of the optical information recording medium and the film thickness of the cover layer 150. As shown in FIG. 52, when the cover layer 150 was formed using the center cap 26 according to the present invention, the cover layer 150 having a film thickness of 75 μm and a substantially uniform film thickness could be obtained. If no condition was used, the film thickness could not be made uniform on the inner and outer circumferences no matter how the conditions were changed.

  When the center cap is not used, the liquid on the inner circumference moves to the outer circumference one after another by centrifugal force, so that the film thickness on the outer circumference becomes thicker than the film thickness on the inner circumference. As shown in FIG. 37, the center cap 26 according to the present invention has an umbrella-shaped portion 26b having a conical shape, for example. Therefore, when the center cap 26 according to the present invention is used, the ultraviolet curable resin liquid dropped on the center cap 26 from the film moved to the outer periphery by centrifugal force is transmitted through the umbrella-shaped portion 26b, for example, in a conical shape. Further, since replenishment is performed from the inner peripheral side, a uniform film can be obtained from the inner peripheral part to the outer peripheral part.

  As described above, the center cap 26 having the umbrella-shaped portion 26b that is inclined from the inner periphery toward the outer periphery, for example, is used for forming the cover layer 150 of the optical information recording medium having one or more information layers. Thus, the single-layer or multilayer optical information recording medium in which the maximum height of the uneven portion 130a formed on the clamp portion 110b of the substrate 110 is significantly lower than the conventional one and has a uniform film thickness from the inner periphery to the outer periphery. Can be obtained.

  Further, a center cap 26 having an umbrella-shaped portion 26b that is inclined from the inner periphery toward the outer periphery, for example, is formed on the intermediate layer 130 and the cover layer 150 of the optical information recording medium having two or more information layers. As a result, it is possible to obtain a multilayer optical information recording medium having a uniform film thickness from the inner periphery to the outer periphery, in which every layer has few radial linear defects 36.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, the present invention can be applied to a medium other than an optical information recording medium as long as a layer is formed on a substrate having a through hole in the center by a spin coating method.

  In the present invention, the layer formed by spin coating may be a layer other than the cover layer and the intermediate layer.

  Further, in Examples 9 and 10, an example in which the outside air introduction hole and the outside air introduction member are provided in the center cap is shown, but the outside air introduction hole and the outside air introduction member are not limited to those shown in FIGS. 48 and 51. That is, as long as it is possible to prevent a negative pressure from being generated in the gap between the center cap and the substrate, the shape of the outside air introduction member, such as the structure of the outside air introduction hole, may be any.

It is sectional drawing which illustrates the structure of the optical information recording medium of a 2 layer structure which was made to reproduce | regenerate and / or record an information signal by irradiating light from the side in which the information layer of the board | substrate was formed. It is a schematic diagram which illustrates the external appearance of the board | substrate which comprises an optical information recording medium. It is a figure which illustrates the conventional center cap 25 used when forming a layer on a board | substrate by a spin coat method. FIG. 6 is a cross-sectional view (No. 1) for explaining a conventional method of forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10; FIG. 6 is a cross-sectional view (No. 2) for explaining a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 11 is a cross-sectional view (No. 3) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 10 is a cross-sectional view (No. 4) for explaining a conventional method of forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 10 is a cross-sectional view (No. 5) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 10 is a cross-sectional view (No. 6) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the optical information recording medium 10 having a two-layer structure. FIG. 11 is a cross-sectional view (No. 7) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 10 is a sectional view (No. 8) for explaining a conventional method of forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10; FIG. 10 is a cross-sectional view (No. 9) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. FIG. 10 is a sectional view (No. 10) for explaining a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10; FIG. 11 is a sectional view (No. 11) for explaining a conventional method of forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10; FIG. 12 is a cross-sectional view (No. 12) for describing a conventional method for forming the intermediate layer 13 and the cover layer 15 by spin coating in the two-layer structure optical information recording medium 10. It is the figure which expanded the peripheral part of the clamp part 11b of the board | substrate 11 in FIG. It is the figure which expanded the peripheral part of the clamp part 11b of the board | substrate 11 in FIG. It is a figure for demonstrating the radial linear defect. 1 is a cross-sectional view illustrating an optical information recording medium 100 according to Example 1 of the invention. It is a schematic diagram which illustrates the schematic structure of the manufacturing apparatus 200 of the optical information recording medium 100 which concerns on this invention. It is sectional drawing (the 1) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 2) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. FIG. 6 is a cross-sectional view (No. 3) for describing the method for manufacturing the optical information recording medium 100 according to the first embodiment of the invention. FIG. 6 is a cross-sectional view (No. 4) for describing the method of manufacturing the optical information recording medium 100 according to the first embodiment of the invention. FIG. 10 is a cross-sectional view (No. 5) for describing the method for manufacturing the optical information recording medium 100 according to the first embodiment of the invention. It is sectional drawing (the 6) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 7) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 8) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 9) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 10) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 11) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is sectional drawing (the 12) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 1 of this invention. It is the figure which expanded the peripheral part of the clamp part 110b of the board | substrate 110 in FIG. It is the top view which looked at the optical information recording medium 100 shown in FIG. 33 from the cover layer 150 side. Is a diagram illustrating the relationship between the incidence of radius R ₁ and the radial linear defects 36 of the cover layer 150 for forming the center cap 25D. It is a diagram illustrating the relationship between the incidence of penetration of the intermediate layer 130 forming the center cap 25C for a radius R ₁ and the ultraviolet curable resin 330. It is a figure which illustrates the center cap 26 which concerns on this invention used when forming a layer on a board | substrate by a spin coat method. It is sectional drawing (the 1) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 4 of this invention. It is sectional drawing (the 2) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 4 of this invention. It is sectional drawing (the 3) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 4 of this invention. It is sectional drawing (the 4) for demonstrating the manufacturing method of the optical information recording medium 100 which concerns on Example 4 of this invention. It is the figure which expanded the peripheral part of the clamp part 110b of the board | substrate 110 in FIG. It is the figure which expanded the peripheral part of the clamp part 110b of the board | substrate 110 in FIG. It is a figure which illustrates the relationship between the maximum height H of the space part 26d of the center cap 26, and the maximum height of the uneven | corrugated | grooved part 130a formed on the clamp part 110b. It is a figure which illustrates the relationship between the maximum height H of the space part 26d, and the incidence rate of the radial linear defect 36. FIG. Is a diagram illustrating the relationship between the maximum height of the concave and convex portion 130a formed on the center cap 26 end surface 26e width W ₂ and a clamping portion on 110b of the. It is a diagram illustrating the relationship between the incidence of the center cap 26C of the width W of the end surface 26e ₂ and the radial linear defects 36. It is a figure which illustrates the center cap 27 based on this invention used when forming a layer on a board | substrate by a spin coat method. FIG. 5 is a diagram illustrating a state in which the fitting portion 25c of the center cap 25 is fitted into the center hole 110a of the substrate 110. FIG. 6 is a diagram illustrating a state in which the fitting portion 27c of the center cap 27 is fitted into the center hole 110a of the substrate 110. It is a figure which illustrates the center cap 28 which concerns on this invention used when forming a layer on a board | substrate by a spin coat method. 4 is a diagram illustrating the relationship between the radial position of the optical information recording medium and the film thickness of a cover layer 150.

Explanation of symbols

10, 100 Optical information recording medium 11, 110 Substrate 11a, 110a Center hole 11b, 110b Clamp part 12 Reflective layer and / or recording layer 13, 130 Intermediate layer 13a, 130a Convex part of intermediate layer 13b, 130b Convex part of intermediate layer 14 Second reflective layer and / or second recording layer 15, 150 Cover layer 15a Concavity and convexity 15b, 150b Convex part 16 of cover layer 16, 160 Laser light 17, 170 Objective lens 21, 210 Rotary table 22, 220 Substrate Positioning part 25, 25A, 25B, 25C, 25D, 26, 26A, 26B, 27, 28 Center cap 25a, 26a, 27a, 28a Projection part 25b, 26b, 27b, 28b Umbrella-shaped part 25c, 26c, 27c, 28c Fit Joint part 25e, 26e, 27e, 28e End face 26d Space part 27x, 28x Outside air introduction hole 28y Outside air introduction member 29a Clearance 33, 330 UV curable resin 34, 340 Stamper 34a, 340a Upper surface of stamper 34 34b, 340b Lower surface of stamper 34 35, 350 Ultraviolet 36 Linear defect 120 Reflective layer 140 Second Reflective layer 200 Manufacturing device 230 Rotating shaft 240 Drive motor 260 UV curable resin supply nozzle 270 UV (UV) irradiation machine H Height R ₁ , R ₂ radius T ₁ , T ₂ thickness W ₂ width

Claims (17)

At least two of the plurality of layers of an optical information recording medium in which a plurality of layers are sequentially laminated on a substrate having a through hole in the center are fitted into the through hole with a center cap having a predetermined radius. , A method for producing an optical information recording medium formed by spin coating,
A radius of a center cap used for forming an upper layer of the at least two layers is larger than a radius of a center cap used for forming a lower layer of the at least two layers. Method.   The optical information recording medium is a two-layer optical information recording medium in which two information layers and an intermediate layer separating the two information layers are alternately stacked on the substrate, and finally a cover layer is stacked. 2. The method of manufacturing an optical information recording medium according to claim 1, wherein the lower layer is the intermediate layer and the upper layer is the cover layer.   The optical information recording medium is an optical information recording medium of three or more layers in which a plurality of information layers and an intermediate layer separating the plurality of information layers are alternately stacked on the substrate, and finally a cover layer is stacked. 2. The method of manufacturing an optical information recording medium according to claim 1, wherein the lower layer is the intermediate layer laminated first, and the upper layer is the intermediate layer laminated later.   The optical information recording medium is an optical information recording medium of three or more layers in which a plurality of information layers and an intermediate layer separating the plurality of information layers are alternately stacked on the substrate, and finally a cover layer is stacked. 2. The method of manufacturing an optical information recording medium according to claim 1, wherein the lower layer is the intermediate layer, and the upper layer is the cover layer.   2. The method of manufacturing an optical information recording medium according to claim 1, wherein a difference between a radius of the center cap used for forming the lower layer and a radius of the center cap used for forming the upper layer is 0.25 mm or more. .   2. The method of manufacturing an optical information recording medium according to claim 1, wherein a radius of a center cap having the smallest radius among the center caps used for forming the plurality of layers is 8.5 mm or more.   2. The method of manufacturing an optical information recording medium according to claim 1, wherein the thickness of the center cap decreases as going from the center of the center cap to the outside.   3. The method of manufacturing an optical information recording medium according to claim 2, wherein the radial position where the formation of the cover layer is started is on the outer peripheral side of the radial position where the formation of the intermediate layer is started.   4. The light according to claim 3, wherein a radial position where the formation of the intermediate layer to be laminated later is started is on an outer peripheral side with respect to a radial position where the formation of the intermediate layer to be laminated first is started. A method for manufacturing an information recording medium.   5. The optical information recording medium according to claim 4, wherein a radial position at which the formation of the cover layer is started is on an outer peripheral side with respect to a radial position at which the formation of the intermediate layer to be finally laminated is started. Production method. The center cap includes a fitting portion fitted into the through hole, and an annular plane provided concentrically with the fitting portion and parallel to the substrate and having a diameter larger than that of the fitting portion. An umbrella-shaped portion having an end surface made of
The end surface is provided so as not to contact the fitting portion in a bottom view, and the fitting portion protrudes from the end surface in a front view, and when the fitting portion is fitted into the through hole, the end surface is 2. The method of manufacturing an optical information recording medium according to claim 1, wherein a space portion is formed between the inner surface of the umbrella-shaped portion and the substrate in contact with the upper surface of the substrate.   12. The method of manufacturing an optical information recording medium according to claim 11, wherein the width of the end face is 2 mm or less.   12. The method of manufacturing an optical information recording medium according to claim 11, wherein the maximum height of the space portion from the upper surface of the substrate is 0.05 mm or more.   12. The method of manufacturing an optical information recording medium according to claim 11, wherein the height of the space portion from the upper surface of the substrate decreases from the center of the umbrella-shaped portion toward the outside.   12. The method of manufacturing an optical information recording medium according to claim 11, wherein the height of the outer surface of the umbrella-shaped part from the upper surface of the substrate decreases from the center of the umbrella-shaped part toward the outside.   The center cap further includes a projection provided concentrically with the umbrella-shaped portion on the top of the umbrella-shaped portion, and an outside air introduction hole penetrating the projection and the fitting portion. The method for producing an optical information recording medium according to claim 11.   The outside air introduction hole has an opening on a side surface of the protrusion, and an outside air introduction member is provided in the vicinity of the opening to introduce outside air into the outside air introduction hole when the center cap rotates. The method of manufacturing an optical information recording medium according to claim 16.

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