Source: http://www.google.com/patents/US7829267?dq=6,587,403
Timestamp: 2017-09-20 20:30:00
Document Index: 358377053

Matched Legal Cases: ['arts 15', 'arts 15', 'arts 5', 'arts 15', 'arts 5', 'arts 15', 'arts 5', 'arts 5', 'arts 5', 'arts 25', 'arts 25', 'arts 15', 'arts 25', 'arts 15', 'arts 25', 'arts 15', 'arts 25', 'arts 25', 'arts 15', 'arts 25', 'arts 15', 'arts 25', 'arts 15']

Patent US7829267 - Stamper, method of forming a concave/convex pattern, and method of ... - Google Patents
A stamper is formed so that a thickness between a concave/convex pattern formation surface, where a concave/convex pattern is formed, and a rear surface gradually decreases in a predetermined area of the stamper. The predetermined area corresponds to an area where pressure is likely to be concentrated...http://www.google.com/patents/US7829267?utm_source=gb-gplus-sharePatent US7829267 - Stamper, method of forming a concave/convex pattern, and method of manufacturing an information recording medium
Publication number US7829267 B2
Application number US 11/653,918
Also published as CN101004551A, CN101004551B, US20070166651
Publication number 11653918, 653918, US 7829267 B2, US 7829267B2, US-B2-7829267, US7829267 B2, US7829267B2
Inventors Minoru Fujita, Mikiharu Hibi
Patent Citations (22), Non-Patent Citations (8), Classifications (19), Legal Events (4)
Stamper, method of forming a concave/convex pattern, and method of manufacturing an information recording medium
US 7829267 B2
A stamper is formed so that a thickness between a concave/convex pattern formation surface, where a concave/convex pattern is formed, and a rear surface gradually decreases in a predetermined area of the stamper. The predetermined area corresponds to an area where pressure is likely to be concentrated when the concave/convex pattern of the stamper is used to form a concave/convex pattern on a substrate. A method of forming a concave/convex pattern uses such stamper, and a method of manufacturing an information recording medium uses a concave/convex pattern formed by such method.
12. A method of manufacturing an information recording medium that manufactures an information recording medium using the concave/convex pattern formed on the substrate in accordance with the method of forming a concave/convex pattern according to claim 8.
As one example of a method of forming a concave/convex pattern using this type of stamper, the specification of U.S. Pat. No. 5,772,905 discloses a nano-imprint lithography method (i.e., a method of forming a concave/convex pattern of nanometer size: hereinafter simply “imprinting method”) that forms a concave/convex pattern of nanometer size on a substrate by pressing a stamper (“mold”) on which a concave/convex pattern of nanometer size has been formed onto a resin layer on a substrate to transfer the concave/convex pattern of the stamper to the resin layer. In this method of forming a concave/convex pattern, polymethyl methacrylate (PMMA: a resin material) is first spin coated on the surface of a substrate made of silicon to form a resin layer (“thin film layer”). Next, after both a multilayer structure, which is composed of the substrate and the resin layer, and the stamper have been heated, as shown in FIG. 1B of the U.S. patent, the entire area of the stamper is pressed onto the resin layer on the substrate with a predetermined pressure. Next, the multilayer structure is left in this state with the stamper pressed thereupon until it reaches room temperature (i.e., a cooling process is carried out), and after this the stamper is separated from the resin layer. By doing so, as shown in FIG. 1C of the U.S. patent, the concave/convex pattern of the stamper is transferred to the resin layer so that concave parts (regions) are formed at the positions where the convex parts were pressed in and convex parts are formed at the positions of the concave parts of the stamper, thereby forming a concave/convex pattern of nanometer size on the substrate (i.e., in the resin layer).
However, by investigating these conventional methods of forming a concave/convex pattern, the present inventors found the following problems. In the method of forming a concave/convex pattern disclosed in U.S. Pat. No. 5,772,905, to transfer the concave/convex pattern, the concave/convex pattern is pressed onto the resin layer with a substantially uniform pressing force being applied to the entire stamper. When doing so, the pressure applied to the surface of the resin layer due to the pressing force applied to the stamper becomes concentrated at an outer edge area of the stamper (i.e., an end area located near the outer edge of the stamper) due to no part of the stamper being present further outside than such area. Accordingly, the pressure applied to the surface of the resin layer at the outer edge area is higher compared to an inner area located further inside than the outer edge area. As a result, due to the excessively high pressure applied to the resin layer at the outer edge area, there is the risk of deformation occurring in the concave/convex pattern transferred to the resin layer. Also, when the pressing force applied to the stamper is lowered to only the force that is required at the outer edge area to avoid deformation of the concave/convex pattern, a situation is produced where in the inner area where the pressure applied to the surface of the resin layer is lower compared to the outer edge area, the concave/convex pattern is insufficiently pressed into the resin layer, resulting in the occurrence of transfer defects in the concave/convex pattern. In this way, with the method of forming a concave/convex pattern disclosed by U.S. Pat. No. 5,772,905, there is the risk of deformation and/or transfer defects in the concave/convex pattern due to the difference in the pressure applied to the surface of the resin layer between the outer edge area and the inner area of the stamper. Also, when a center hole is present in either of the stamper and the substrate, when a concave/convex pattern is formed in a resin layer in accordance with the method of forming a concave/convex pattern disclosed by U.S. Pat. No. 5,772,905, the pressure applied to the surface of the resin layer increases not only at the outer edge area described above but also at the rim area of the center hole (i.e., an end area near the rim of the center hole).
Preferred embodiments of a stamper, a method of forming a concave/convex pattern, and a method of manufacturing an information recording medium according to the present invention will now be described with reference to the attached drawings.
The stamper 1 shown in FIG. 1 is a matrix for manufacturing a magnetic disk 11 (one example of an “information recording medium” for the present invention) shown in FIG. 2 in accordance with a method of manufacturing an information recording medium according to the present invention, and is formed in an overall circular plate-like shape. Here, the magnetic disk 11 is a discrete track-type magnetic recording medium (a “patterned medium”) on which data can be recorded by perpendicular recording, for example. As shown in FIG. 2, a recording layer (a magnetic recording layer) 13 is formed on a substrate 12, and a center hole 14 through which a rotational shaft (not shown) of a motor passes is formed in the center of the magnetic disk 11. Note that although in reality a variety of functional layers such as a soft magnetic layer and an intermediate layer are formed between the substrate 12 and the recording layer 13, for ease of understanding the present invention, such layers have been omitted from the description and the drawings. Concave/convex patterns 15 that function as data track patterns and servo patterns are formed in the recording layer 13 of the magnetic disk 11 by forming a plurality of convex parts 15 a (magnetic recording areas), at least protruding end parts of which are formed of magnetic material, and a plurality of concave parts 15 b (non-recording areas).
On the other hand, as shown in FIG. 3, the stamper 1 is in the overall shape of a thin plate and is constructed by forming a nickel layer 3 on a nickel layer 2 by electroforming using the nickel layer 2 as an electrode. As shown in FIG. 1, a center hole 4 is also formed in a center Pc (a “center area Ac”) of the stamper 1. Here, as one example, the stamper 1 is formed so that the diameter (i.e., outer diameter) thereof is equal to the diameter of the magnetic disk 11 described above and the inner diameter of the center hole 4 is equal to the inner diameter of the center hole 14 of the magnetic disk 11. Also, a concave/convex pattern 5 with a plurality of convex parts 5 a formed corresponding to the concave parts 15 b of the magnetic disk 11 and a plurality of concave parts 5 b formed corresponding to the convex parts 15 a is formed on a concave/convex pattern formation surface 6 (the lower surface in FIG. 3) of the stamper 1. Note that in the present specification, as shown in FIG. 3, a plane that matches the bottom surfaces of the concave parts 5 b in the concave/convex pattern 5 (the plane shown by the dot-dash line X in FIG. 3) is referred to as the concave/convex pattern formation surface 6. Here, depending on the method of manufacturing, in some cases the bottom surfaces of the concave parts 5 b do not lie on the same plane, and in this case a plane including the bottom surface of any of the concave parts 5 b can be set as the concave/convex pattern formation surface 6. Also, as shown in FIG. 1, the stamper 1 is formed so that the thickness between the concave/convex pattern formation surface 6 on which the concave/convex pattern 5 is formed and a rear surface (the upper surface in FIG. 1) of the stamper 1 gradually decreases in an outer edge area Ao toward an outer edge Po of the stamper 1 and gradually decreases in a rim area Ae (i.e., an area including a rim Pe of the center hole 4) toward the rim Pe (i.e., toward the center Pc).
First, as shown in FIG. 4, a preform 10 (one example of a “substrate” for the present invention) that has a resist layer 21 (one example of a “resin layer” for the present invention) formed on a surface thereof is set on a substrate attachment portion 32 of a press 31. Here, the preform 10 is used to manufacture the magnetic disk 11 and is constructed with the recording layer 13 formed on the substrate 12. Next, the stamper 1 is set on a stamper attachment portion 33 of the press 31 with the concave/convex pattern formation surface 6 facing downward. Here, as one example, a magnet or a vacuum chuck mechanism for holding the stamper 1 is disposed on the stamper attachment portion 33. Note that in FIG. 4 and in FIGS. 5 and 6 described later, the gaps produced between the rear surface 7 of the stamper 1 and the stamper attachment portion 33 are exaggerated.
Next, any resist (“residue”: not shown) remaining on the bottom surfaces of the concave parts 25 b in the concave/convex pattern 25 in the resist layer 21 on the preform 10 is removed by an oxygen plasma process, for example. After this, by etching the preform 10 (i.e., the recording layer 13) using the concave/convex pattern 25 (i.e., the convex parts 25 a) as a mask, the concave/convex patterns 15 are formed on the substrate 12. When doing so, the convex parts 15 a are formed corresponding to the convex parts 25 a in the concave/convex pattern 25 and the concave parts 15 b are formed corresponding to the concave parts 25 b in the concave/convex pattern 25. After this, by carrying out another etching process, the resist layer 21 remaining on the recording layer 13 (i.e., on the convex parts 15 a) is removed. By doing so, the magnetic disk 11 is completed as shown in FIG. 2, thereby completing the method of manufacturing an information recording medium according to the present invention.
On the other hand, as shown in FIG. 12, when the diameter (i.e., the outer diameter) of a stamper 1D is larger than the diameter (i.e., the outer diameter) of a preform 10D, during imprinting on the resist layer 21 (not shown) on the preform 10D, the pressure applied to the surface of the resist layer 21 is concentrated in an area where the outer edge area of the preform 10D coincides with the stamper 1D. Also, with the stamper 1D in which the center hole 4 is not formed, during imprinting on the resist layer 21 on the preform 10 in which the center hole 14 is formed, the pressure applied to the surface of the resist layer 21 is concentrated in an area where the rim area of the preform 10D coincides with the stamper 1D. Accordingly, the stamper 1D shown in FIG. 12 is formed so that in a middle area Am1 between the outer edge Po and the center Pc (one example of a “predetermined area” for the present invention), the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in an area Am1 o (one example of a “first area” for the present invention) on the outer edge Po side of the middle area Am1 as the distance increases from a middle position Pm1 in the radial direction of the middle area Am1 (in this example, the middle position Pm1 is a predetermined position which is closer to the center Pc than the middle position Pm of the stamper 1 described earlier) and the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in an area Am1 c (one example of a “second area” for the present invention) on the center Pc side of the middle area Am1 as the distance increases from the middle position Pm1 in the radial direction of the middle area Am1.
In this way, according to the stampers 1, 1A to 1C described above and a method of forming a concave/convex pattern using any of the stampers 1, 1A to 1C, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in the outer edge area Ao (an “end area”) toward the outer edge Po, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 during imprinting is concentrated in the outer edge area Ao of the stamper, and therefore deformation of the concave/convex pattern 25 in at least the outer edge area Ao can be avoided. Since it is not necessary to lower the pressing force applied to the stamper 1, 1A to 1C, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5 in an inner area (i.e., an area further inside than the outer edge area Ao). By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire preform 10. Therefore, according to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision at positions corresponding to both the outer edge area Ao and the inner area of the stampers 1, 1A to 1C.
Also, according to the stampers 1, 1A, 1E, 1F described above and a method of forming a concave/convex pattern using any of the stampers 1, 1A, 1E, 1F, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in the rim area Ae (an “end area”) toward the rim Pe, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 during formation of the concave/convex pattern is concentrated at the rim area Ae of the stampers 1, 1A, 1E, 1F, and therefore deformation of the concave/convex pattern 25 in at least the rim area Ae can be avoided. Since it is not necessary to lower the pressing force applied to the stampers 1, 1A, 1E, 1F, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5 in an outer area (i.e., an area further outside than the rim area Ae). By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire preform 10. Therefore, according to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision at positions corresponding to both the rim area Ae and the outer area of the stampers 1, 1A, 1E, 1F.
Also, according to the stampers 1, 1A described above and a method of forming a concave/convex pattern using any of the stampers 1, 1A, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in the outer edge area Ao toward the outer edge Po and gradually decreases in the rim area Ae toward the rim Pe, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 is concentrated at the outer edge area Ao and the rim area Ae (both “end areas”) of the stamper without lowering the pressing force applied to the stampers 1, 1A during imprinting. By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire preform 10 by pressing the concave/convex pattern 5 into the resist layer 21 with uniform pressure across the entire stamper. Also, according to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision across the entire stamper.
In addition, according to the stamper 1D described above and the method of forming a concave/convex pattern using the stamper 1D, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in at least one (in the illustrated example, both) of the area Am1 o on the outer edge Po side and the area Am1 c on the center Pc side of the “predetermined area” for the present invention (in this example, the middle area Am1) as the distance from the middle position Pm1 increases, as examples it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 during formation of the concave/convex pattern 25 on a preform 10D whose diameter is smaller than the diameter of the stamper 1D is concentrated at an area where the outer edge area of the preform 10D coincides with the stamper 1D (i.e., the outer edge side of the predetermined area: in this example, the outer edge Po side of the middle area Am1), and to avoid a situation where the pressure applied to the surface of the resist layer 21 during formation of the concave/convex pattern 25 on the preform 10D in which the center hole 14 is formed using a stamper 1D in which the center hole 4 is not formed is concentrated at an area where the rim area of the preform 10D coincides with the stamper 1D (i.e., the center side of the predetermined area: in this example, the center Pc side of the middle area Am1), and therefore deformation of the concave/convex pattern 25 can be avoided in at least such areas (i.e., the outer edge Po side and the center Pc side of the middle area Am1). Also, since it is not necessary to lower the pressing force applied to the stamper 1D, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5, such as at the middle position Pm1 of the middle area Am1. By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire stamper including the middle area Am1. According to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision, such as at a position corresponding to the middle area Am1 of the stamper 1D.
The stamper 1G shown in FIG. 15 is a matrix for manufacturing the magnetic disk 11 in accordance with the method of manufacturing an information recording medium according to the present invention and corresponds to another example of a “stamper” according to the present invention. Here, as one example, the stamper 1G is formed so that the diameter (outer diameter) thereof is equal to the diameter of the magnetic disk 11 and so that the inner diameter of the center hole 4 is equal to the inner diameter of the center hole 14 of the magnetic disk 11. The stamper 1G is also formed so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 (the upper surface in FIG. 15) gradually decreases in the outer edge area Ao toward the center Pc (i.e., toward the rim Pe) and gradually decreases in the rim area Ae (an area that includes the rim Pe of the center hole 4) toward the outer edge Po.
Next, any resist (“residue”) remaining on the bottom surfaces of the concave parts 25 b in the concave/convex pattern 25 in the resist layer 21 on the preform 10 is removed by an oxygen plasma process, for example. After this, by etching the preform 10 (i.e., the recording layer 13) using the concave/convex pattern 25 (i.e., the convex parts 25 a) as a mask, the concave/convex patterns 15 are formed on the substrate 12. When doing so, the convex parts 15 a are formed corresponding to the convex parts 25 a in the concave/convex pattern 25 and the concave parts 15 b are formed corresponding to the concave parts 25 b in the concave/convex pattern 25. After this, by carrying out another etching process, the resist layer 21 remaining on the recording layer 13 (i.e., on the convex parts 15 a) is removed. By doing so, the magnetic disk 11 is completed as shown in FIG. 2, thereby completing the method of manufacturing an information recording medium according to the present invention.
On the other hand, as shown in FIG. 24, when the diameter (outer diameter) of the stamper 1K is larger than the diameter (outer diameter) of the preform 10D, during imprinting on the resist layer 21 (not shown) on the preform 10D, the pressure applied to the surface of the resist layer 21 is concentrated in an area where an area located further inside than the outer edge area of the preform 10D coincides with the stamper 1K. With the stamper 1K where the center hole 4 is not formed, during imprinting on the resist layer 21 on the preform 10 in which the center hole 14 is formed, the pressure applied to the surface of the resist layer 21 is concentrated in an area where an area located outside the rim area of the preform 10D coincides with the stamper 1K. Accordingly, the stamper 1K shown in FIG. 24 is formed so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in an area Am1 o (one example of a “first area” for the present invention) on the outer edge Po side of the middle area Am1 between the outer edge Po and the center Pc toward a middle position Pm1 in the radial direction of the middle area Am1 (in this example, the middle position Pm1 is a predetermined position which is closer to the center Pc than the middle position Pm of the stamper 1G described earlier) and so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in an area Am1 c (one example of a “second area” for the present invention) on the center Pc side of the middle area Am1 toward the middle position Pm1.
In this way, according to the stampers 1G to 1J described above and the method of forming a concave/convex pattern using any of the stampers 1G to 1J, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in the outer edge area Ao (an “end area”) toward the center Pc, when, for example, an elastic body 35 with a diameter that is equal to or larger than the diameters of the stampers 1G to 1J is used during imprinting, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 is concentrated in an inner area of the stampers 1G to 1J (i.e., an area located further inside than the outer edge area Ao), and therefore deformation of the concave/convex pattern 25 in at least such inner area can be avoided. Since it is not necessary to lower the pressing force applied to the stampers 1G to 1J to avoid deformation of the concave/convex pattern 25, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5 in the outer edge area Ao. Also, since the stampers 1G to 1J are constructed so that the thickness gradually increases in the outer edge area Ao toward the outer edge Po, when an elastic body with a diameter that is equal to or larger than the diameters of the stampers 1G to 1J is used when forming the concave/convex pattern 25, the distance between the rear surface 7 and the stamper attachment portion 33 is reduced at a position (i.e., the outer edge area Ao) where the stampers 1G to 1J are thick, and therefore deformation of the elastic body 35 is sufficiently reduced. Accordingly, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 falls in the outer edge area Ao of the stampers 1G to 1J, and as a result, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 25 in the outer edge area Ao. By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire resist layer 21. Therefore, according to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision at positions corresponding to both the inner area and the outer edge area Ao of the stampers 1G to 1J.
In this way, according to the stampers 1G, 1H, 1L, 1M described above and the method of forming a concave/convex pattern using any of the stampers 1G, 1H, 1L, 1M, by forming the stamper so that the thickness between the concave/convex pattern formation surface 6 and the rear surface 7 gradually decreases in the rim area Ae (an “end area”) toward the outer edge Po, when, for example, an elastic body 35 is used during imprinting, it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 is concentrated in an outer area (an area located further outside than the rim Pe) of the stampers 1G, 1H, 1L, 1M, and therefore deformation of the concave/convex pattern 25 in at least such outer area can be avoided. Also, since it is not necessary to lower the pressing force applied to the stamper 1G, 1H, 1L, or 1M, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5 in the rim area Ae. In addition, since the stampers 1G, 1H, 1L, and 1M are constructed so that the thickness gradually increases in the rim area Ae toward the rim Pe, if the elastic body 35 is used when forming the concave/convex pattern 25, the distance between the rear surface 7 and the stamper attachment portion 33 is reduced at a position (i.e., the rim area Ae) where the stampers 1G, 1H, 1L, 1M are thick, and therefore deformation of the elastic body 35 can be sufficiently reduced. Accordingly, since it is possible to avoid a situation where the pressure applied to the surface of the resist layer 21 falls in the rim area Ae of the stampers 1G, 1H, 1L, 1M, it is possible to avoid the occurrence of transfer defects in the concave/convex pattern 5 in the rim area Ae. By doing so, it is possible to form the concave/convex pattern 25 with high precision across the entire resist layer 21. Therefore, according to a method of manufacturing an information recording medium that manufactures an information recording medium (the magnetic disk 11) using the concave/convex pattern 25 formed by this method of forming a concave/convex pattern (or alternatively a concave/convex pattern where the positional relationship between the concaves and convexes matches the concave/convex pattern 25) as a mask pattern, it is possible to provide a magnetic disk 11 where the concave/convex patterns 15 are formed with high precision at positions corresponding to both the rim area Ae and the outer area of the stampers 1G, 1H, 1L, 1M.
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JP2000195042A Title not available
JP2000334744A * Title not available
JP2004295989A Title not available
JP2005100496A Title not available
JPH0997419A Title not available
WO2005029471A1 Sep 9, 2004 Mar 31, 2005 Tdk Corporation Process for producing magnetic recording medium and magnetic recording medium
1 English Language Abstract of JP 2000-195042.
2 English Language Abstract of JP 2003-157520.
3 English Language Abstract of JP 2004-295989.
4 English Language Abstract of JP 2005-100496.
5 English Language Abstract of JP 9-97419.
6 * Translation JP-2000-334744(Dec. 2000).
7 U.S. Appl. No. 11/610,731 to Hibi et al., filed Dec. 14, 2006.
8 U.S. Appl. No. 11/677,321 to Fujita et al., filed Feb. 21, 2007.
U.S. Classification 430/321, 430/320, 264/1.33
International Classification G03C5/00, B29D17/00
Cooperative Classification G11B7/263, B29C2043/025, B29C2033/426, B29C2043/5858, G11B5/855, B29C2043/3655, B29C43/361, B29C43/021, B29D17/005, B29C33/424
European Classification B29C43/36C, B29C43/02B, G11B5/855, B29D17/00C
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FUJITA, MINORU;HIBI, MIKIHARU;REEL/FRAME:018807/0467;SIGNING DATES FROM 20061219 TO 20061222