JP2008217942A - Stacked type stamper and manufacturing method of stacked type stamper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stacked type stamper having a durable composition, and a manufacturing method for easily manufacturing the stacked type stamper. <P>SOLUTION: Almost the same state is given to a first interface 3 being a joint surface between a first metal layer 2 and a polymer film 4 as a heat insulating layer and a second interface 5 being a joint surface between a second metal layer 6 and the polymer film 4, and both interfaces 3 and 5 coming into contact with a polymer material 4' being in a liquid state are set to the same state allowing an anchor effect of the polymer to be sufficiently revealed, and thus the problem of exfoliation due to conventional difference between interface states is resolved to improve the durability. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stacked stamper including a first metal layer having a stamper surface, a heat insulating layer, and a second metal layer, and a method for manufacturing the same.

  In a stamper used for forming an optical disk substrate, a heat insulating stamper having a heat insulating function is used in order to ensure high mass productivity and improve the substrate quality. The heat insulating stamper has a laminated structure, and includes a first metal layer having a stamper surface having a concavo-convex information sequence to be transferred to a molded substrate, a heat insulating layer bonded onto the first metal layer, and the heat insulating layer. And a second metal layer bonded to each other in sequence.

  An example of a manufacturing method for producing the laminated stamper is described in Patent Document 1. In Patent Document 1, after a first metal layer having a stamper surface is formed, a polymer film is formed as a heat insulating layer on the surface opposite to the stamper surface, and a second metal layer is formed on the polymer film. . Similar to the first metal layer, the second metal layer is formed by electroplating, so that the polymer film must be made conductive. Therefore, a metal thin film is formed on the polymer film by sputtering or the like, and the second metal layer is formed by electrolytic plating using the metal thin film as a cathode.

  The inventors actually performed substrate molding using the multilayer stamper manufactured as described above. As a result, it was found that interface peeling occurred at the second interface, that is, the joint surface between the heat insulating layer and the second metal layer after tens of thousands of shots. Although this phenomenon did not become apparent in the case of substrate molding with a small number of lots (50,000 shots or less), this phenomenon was clearly found in the case of substrate molding with a large number of lots (more than 100,000 shots).

  As a result of the demonstration test, it was found that the laminated stamper has a problem in terms of durability, although it has a heat insulating function and has no problem in mass productivity. In addition, it is characteristic that the interface where peeling occurs is the second interface, and no peeling occurs at the first interface.

  In response to this result, the bonding surface of the first metal layer in contact with the first interface of the polymer film as the heat insulating layer and the bonding surface of the second metal layer in contact with the second interface of the polymer film were observed. It was found that there were minute irregularities on the bonding surface of the first metal layer, and the bonding surface of the second metal layer was in a mirror state with almost no irregularities. That is, it has been clarified that the durability of the first interface is superior to that of the second interface due to the anchor effect generated when the polymer film as the heat insulating layer enters the minute irregularities present on the surface.

  On the other hand, since the second interface forms the second metal layer on the substantially mirror-finished polymer film, there is almost no element that generates a polymer anchor effect. It became clear that this difference in interface state was a factor that appeared as a difference in durability.

  As inventions aimed at improving durability, for example, methods described in Patent Documents 2 to 4 have been proposed. However, these methods are methods that add a new process to a conventional process or require a new material.

In view of the above-described conventional problems, an object of the present invention is to provide a laminated stamper having a durable configuration and a manufacturing method capable of easily manufacturing the laminated stamper.
Japanese Patent No. 3378840 JP 2002-83450 A JP 2002-150625 A JP 2002-184046 A

  In order to achieve the object, the invention according to claim 1 is provided with a heat insulating layer on the other surface of the first metal layer in which a stamper surface for transferring a predetermined shape is formed on the resin surface to be molded, and the heat insulating layer. In the stacked stamper having the second metal layer thereon, a first interface that is a joint surface between the first metal layer and the heat insulation layer, and a joint surface between the second metal layer and the heat insulation layer are provided. The interface state between the first metal layer and the second metal layer and the heat insulating layer is the same, and the anchor of the similar heat insulating layer at the corresponding part Since the effect is exhibited, the conventional problem due to the difference in the interface state is solved, and a laminated stamper excellent in durability can be obtained.

  As described in claim 2, in the invention described in claim 1, it is effective to set the surface roughness Ra on the surface of the first metal layer and the surface of the second metal layer to 0.5 to 3 μm. .

  As described in claim 3, the invention described in claim 1 is applied to the molding of an optical disk substrate to which an uneven information string is transferred.

  Invention of Claim 4 is a manufacturing method which manufactures the lamination type stamper of any one of Claims 1-3, Comprising: The 1st metal layer by which the stamper surface was formed in one surface, and this 1st metal layer A heat insulating layer in a liquid state is disposed between the second metal layer and the second metal layer facing each other, and the heat insulating layer is cured so that both the metal layers are in contact with the heat insulating layer in the liquid state. Thus, since the heat insulating layer is formed from the liquid state, a sufficient anchor effect of the heat insulating layer is exhibited at the interface between the first metal layer and the second metal layer and the heat insulating layer.

  As described in claim 5, in the invention according to claim 4, the surface roughness Ra on the surface of the first metal layer and the surface of the second metal layer in contact with the heat insulating layer in the liquid state is 0.5 to 3 μm. It is effective to be.

  According to the multilayer stamper according to the present invention, the first interface that is a bonding surface between the first metal layer having the stamper surface and the heat insulating layer, and the second interface that is a bonding surface between the second metal layer and the heat insulating layer. Since the anchor effect of the same heat insulation layer is expressed at both interfaces, the problem due to the difference in the interface state as in the past is eliminated, and the laminate has excellent durability. A mold stamper can be provided.

  Further, according to the method for manufacturing a laminated stamper according to the present invention, since the heat insulating layer is formed from a liquid state, a sufficient anchor effect is exhibited at the interface between the first metal layer and the second metal layer and the heat insulating layer. As a result, the conventional problems due to the difference in the interface state are solved, and a laminated stamper having excellent durability can be easily manufactured.

  As described above, as a result of the verification test by the inventors, in the conventional stacked stamper including the first metal layer having the anchor surface, the heat insulating layer, and the second metal layer, the first of the polymer film that is the heat insulating layer is used. When observing the bonding surface of the first metal layer in contact with the interface and the bonding surface of the second metal layer in contact with the second interface of the polymer film, there are minute irregularities on the bonding surface of the first metal layer, It has been found that the bonding surface of the second metal layer is in a mirror state with almost no unevenness. That is, it has been clarified that the durability of the first interface is superior to that of the second interface due to the anchor effect generated when the polymer film as the heat insulating layer enters the minute irregularities present on the surface. On the other hand, since the second interface forms the second metal layer on the substantially mirror-finished polymer film, there is almost no element that generates a polymer anchor effect. It became clear that this difference in interface state was a factor that appeared as a difference in durability.

  According to the inventor's consideration, the durability problem in the laminated stamper is a result depending on the conventional manufacturing method. If the anchor effect of the heat insulating layer at the interface is effectively used, a complicated method is not used. In both cases, it was found that a sufficient bonding force was obtained, the occurrence of interfacial peeling at the bonding surface between the heat insulating layer and the second metal layer as in the prior art could be prevented, and the durability improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A to 1E are explanatory views of a manufacturing process of a stacked stamper and a manufacturing method thereof for explaining Embodiment 1 of the present invention. As shown in FIG. 1E, the basic structure of the multilayer stamper in the present embodiment is a first metal layer 2 of a Ni electroformed layer having a stamper surface 1 formed on one surface, and the first metal layer 2. The polymer film 4 that is a heat insulating layer in contact with the stamper surface 1 as the first interface 3 and the Ni electroforming in which the surface of the polymer film 4 opposite to the first interface 3 is in contact as the second interface 5 The second metal layer 6 is a layer.

  Next, a manufacturing method of the stacked stamper in Embodiment 1 will be described.

  First, a polymer material 4 ′ in a liquid state is dropped on the other side surface of the first metal layer 2 that is formed by Ni electroforming and has a concavo-convex pattern as the stamper surface 1 on one side surface (FIG. 1). (A)) Thereafter, the first metal layer 2 is rotated (FIG. 1B), and the dropped polymer material 4 ′ is caused to flow to a predetermined thickness (FIG. 1C).

  Next, the second metal layer 6 produced by Ni electroforming is placed on the polymer material 4 ′ (FIG. 1D), and a series of stacking steps is completed (FIG. 1E). . Thereafter, a laminated structure stamper is completed through a heat treatment step in which the liquid polymer material 4 ′ is cured to form the polymer film 4.

  The liquid polymer material 4 ′ used in the present embodiment is polyamideimide (manufactured by Toyobo: Viromax). The liquid polymer material 4 ′ is dropped on the first metal layer 2, and the polymer film 4 is formed as a heat insulating layer having a thickness of 50 μm by spin coating.

  The second metal layer 6 is placed on the polymer material 4 ′ in the liquid state. At this time, air should be taken care of. In the present embodiment, as shown in FIG. 1 (d), air is prevented from being caught by gradually bringing the second metal layer 6 into contact with the polymer material 4 'in the liquid state while warping.

  If it is difficult to stack while warping due to the thickness of the second metal layer 6 (for example, 200 μm or more), a thin second metal layer (for example, 100 μm or less) is produced and stacked while warping as described above. After that, the thin second metal layer can be subjected to electrolytic plating again to a predetermined thickness to obtain a laminated stamper having a final shape.

  In the present embodiment, a first interface 3 that is a bonding surface between the first metal layer 2 and the polymer film 4 that is a heat insulating layer, and a second interface that is a bonding surface between the second metal layer 6 and the polymer film 4. As a result of measuring the roughness of the contact surfaces of the produced first metal layer 2 and second metal layer 6 and the polymer film 4, the surface roughness Ra is as follows. It was 1 μm.

  Moreover, the observation result (2000 times) by the electron microscope (SEM) in the contact surface with the polymer film 4 in the 1st metal layer 2 and the 2nd metal layer 6 is shown in FIG. Both contact surfaces were in the same state. As shown in FIG. 3, according to the present embodiment, the surface of the first metal layer 2 and the second metal layer 6 that are in contact with the polymer material 4 ′ in the liquid state is sufficient to exhibit the polymer anchor effect. You can see that it has irregularities.

  As a result, the same anchor effect is expressed at both interfaces 3 and 5 of the first metal layer 2 and the second metal layer 6 and the polymer film 4, and therefore, peeling due to the difference in the interface state as in the prior art. This problem is solved, and the laminated stamper as a whole has excellent durability.

  2A to 2D are explanatory views of a manufacturing process of a stacked stamper and a manufacturing method thereof for explaining the second embodiment of the present invention. The basic structure of the stacked stamper in the second embodiment is the same as that in the first embodiment. In the following description, the same reference numerals are used for members corresponding to the members described in FIGS. It was attached.

  A method for manufacturing the stacked stamper according to the second embodiment will be described.

  First, a polymer material 4 ′ in a liquid state is dropped on the other side surface of the first metal layer 2 that is formed by Ni electroforming and has a concavo-convex pattern as the stamper surface 1 on one side surface (FIG. 2). (A)) The second metal layer 6 is placed on the polymer material 4 ′ (FIG. 2B). In this state, the first metal layer 2 and the second metal layer 6 are rotated (FIG. 2C), and the polymer material 4 ′ sandwiched between the first metal layer 2 and the second metal layer 6 flows. To a predetermined film thickness (FIG. 2D). Thereafter, a laminated stamper is completed through a heat treatment step in which the polymer material 4 ′ in the liquid state is cured to form the polymer film 4.

  The liquid polymer material 4 ′ used in Embodiment 2 is polyamideimide (Toyobo Co., Ltd .: Viromax) as in Embodiment 1. The liquid crystal polymer material 4 ′ is dropped onto the first metal layer 2 to produce the stacked stamper as described above. The advantage of the second embodiment is that the second metal is used to prevent air entrainment. The thickness of the layer 6 is not restricted. As is apparent from the figure, the polymer material 4 'spreads on the contact surface while excluding air on the contact surface.

  According to the measurement results for the stacked stamper of the second embodiment, the roughness and surface state of the contact surfaces of the first metal layer 2 and the second metal layer 6 and the polymer film 4 as the heat insulating layer are the same as those of the first embodiment. there were.

  When molding was performed with the multilayer stampers obtained in the first and second embodiments, it was confirmed that the durability was 100,000 shots or more. Further, the quality and molding tact of the molded product by the multilayer stamper were the same as those by the conventional multilayer stamper.

  An example of the usage of the multilayer stamper according to the present embodiment is resin molding of an optical disk substrate. As a specific example, the laminated stamper of the present embodiment is placed on at least one of a fixed mold and a movable mold, and a molten resin material is filled into a cavity formed by the fixed mold and the movable mold. Thus, an optical disk substrate having a predetermined shape is formed.

  The present invention is applied to a resin molding stamper having a heat insulating laminated structure including a first metal layer, a heat insulating layer, and a second metal layer, and in particular, an optical disc substrate for optically recording / reproducing or erasing information. It is effective as a stamper.

(A)-(e) is explanatory drawing of the manufacturing process of the laminated stamper for demonstrating Embodiment 1 of this invention, and its manufacturing method. (A)-(d) is explanatory drawing of the manufacturing process of the lamination type stamper for demonstrating Embodiment 2 of this invention, and its manufacturing method. The figure which shows the SEM observation result (2000 time) of the contact surface with the polymer film in the 1st metal layer and 2nd metal layer of the lamination type stamper of this embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stamper surface 2 1st metal layer 3 1st interface 4 Polymer film 4 'Polymer material 5 of a liquid state 5 2nd interface 6 2nd metal layer 6

Claims (5)

In a laminated stamper comprising a heat-insulating layer on the other surface of the first metal layer on which a stamper surface for transferring a predetermined shape to the resin surface to be molded is formed, and a second metal layer on the heat-insulating layer,
The state of the first interface, which is a joint surface between the first metal layer and the heat insulation layer, and the second interface, which is a joint surface between the second metal layer and the heat insulation layer, are substantially the same. A stacked stamper.   2. The multilayer stamper according to claim 1, wherein a surface roughness Ra between the surface of the first metal layer and the surface of the second metal layer is 0.5 to 3 μm.   The multilayer stamper according to claim 1, wherein the object to be molded is an optical disk substrate onto which an uneven information string is transferred. It is a manufacturing method which manufactures the lamination type stamper according to any one of claims 1 to 3,
A liquid heat insulating layer is disposed between a first metal layer having a stamper surface formed on one surface and a second metal layer facing the first metal layer, and the two metal layers are connected to the liquid heat insulating layer. A method of manufacturing a laminated stamper, characterized in that the heat insulating layer is cured in contact therewith.   5. The multilayer stamper according to claim 4, wherein the surface roughness Ra of the surface of the first metal layer and the surface of the second metal layer in contact with the liquid heat insulating layer is 0.5 to 3 μm. Production method.