JP2007050695A - Molding die, molding stamper, optical disc substrate and optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding die and a stamper for molding which can be homogeneously peeled, even if fluctuation in a ring slit width for blowing out a compressed air in a molding die on releasing of a molded matter from the mold for transferring a micropattern occurrs, an optical disk substrate and an optical information recording medium made by using the above. <P>SOLUTION: The molding die for the optical disk substrate includes two domains of a read only ROM domain and a recording and regeneration domain capable of at least one of recoding, regeneration and erasing on the same plane, has a molding stamper where information related with the ROM domain described above is recorded in a given domain on the inner periphery, and keeps a cavity constructing plane of the mold member where the stamper for molding described above is put on equipped with a means for a temporary pressure accumulating function for compressed air for mold releasing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a read-only area (hereinafter sometimes referred to as a “ROM area”) and a recording / reproducing area in which at least one of information recording, information reproduction, and information erasing can be performed within the same plane. And a molding die and a molding stamper used for manufacturing an optical disk substrate in which two types of regions are mixed, and an optical disk substrate and an optical information recording medium (hereinafter referred to as “optical recording medium”, “optical disk”) manufactured using them. May also be referred to).

Conventionally, optical information recording media having a ROM area in advance are known as multifunctional recording optical disks (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). In such an optical recording medium, predetermined information is recorded as a physically uneven shape in a ROM area on the inner periphery thereof, and a recording / reproducing area on which the user can record is provided on the outer periphery. Information on this ROM area is recorded in a program memory area (PMA area) existing on the innermost periphery of the optical recording medium, and is treated as if it were the first session recorded on a blank disc.
In manufacturing such an optical recording medium, uneven patterns having different depths are mixed on the molded substrate. It is a pit area that functions as a ROM and a groove area that enables recording.
Since both require different signal outputs after the recording film is formed, the concave-convex pattern formed on the surface of the optical disk substrate has a physically different depth. Specifically, the pit area tends to be deeper than the groove area.

FIG. 12 is a schematic view showing the structure of the inner periphery of a conventional molding die. In FIG. 12, a molding die includes a molding stamper 1, a fixed mirror surface block 2 on which the molding stamper 1 is mounted and having a fitting projection 2a, a sleeve 4 on the inner periphery of the fixed mirror surface block 2, A sprue bush 5 on the inner periphery of the sleeve 4 and a support plate 6 that supports the sprue bush 5 are configured.
FIG. 13 is a schematic plan view showing a stamper in which two types of regions used for substrate manufacture are mixed. 14 is a schematic cross-sectional view taken along line AA in FIG. As shown in FIG. 13 and FIG. 14, the problem that the uneven patterns having different depths, for example, the pit portion (ROM region) 1 a and the groove (recording / reproducing region) 1 b have been allowed to be revealed. It is an abnormal transfer of local pits in the substrate surface.
In normal substrate molding, a molten metal is filled in a molding die on which a molding stamper 1 on which an uneven pattern of information is formed is placed and solidified, and then the substrate is taken out. In this substrate removal, in order to peel the molded substrate from the molding stamper, compressed air is ejected from the inner peripheral portion of the mold cavity surface on which the molding stamper is placed, and peeling is performed using the pressure. . Therefore, in order to eject compressed air, it is necessary to provide a minute annular slit in the inner peripheral portion of the molding die. However, due to the processing accuracy or assembly accuracy of this annular slit, there was a variation in the slit width in the annular periphery.
Such fluctuations in the slit width are a cause directly connected to fluctuations in the peeling force in the peeling method using compressed air, and the fluctuations in the peeling force have revealed the phenomenon of abnormal transfer. That is, the flow rate is relatively increased in a portion having a wide slit width, a strong peeling force is generated, and the molded substrate is greatly deformed.

FIG. 15 is a schematic diagram showing a variation state of the slit width. FIG. 16 is a schematic view showing a peeled state of a portion A in FIG. 15 of a conventional molding die. FIG. 17 is a schematic diagram showing a peeled state of the B part of FIG. 15 of a conventional molding die.
15 to 17 show the peeled state of the substrate when the annular slit width varies. This slit is, for example, a gap between the sleeve 4 in FIG. 12 and the fitting protrusion 2 a of the fixed mirror surface block 2.
In addition, as described above, this slit may be biased due to the processing accuracy or assembly accuracy. In a portion having a wide slit width (portion A in FIG. 15), the flow rate of compressed air is relatively increased and a strong peeling force is generated, and the molded substrate 7 is greatly deformed as shown in FIG. On the other hand, only a relatively weak peeling force is generated in a portion having a narrow slit width (B portion in FIG. 15), and the deformation amount of the molded substrate 7 becomes small as shown in FIG. Further, the holding state of the substrate deformation is affected by the supply state of the compressed air.
If peeling is started without the compressed air for peeling having sufficient pressure and capacity, peeling cannot proceed continuously, and as a result, the deformed state of the molded substrate 7 is kept long.
The substrate deformation at the time of peeling causes a relative positional deviation between the uneven pattern on the molding stamper 1 and the molding substrate 7 when the molding substrate 7 is separated from the molding stamper 1 at the boundary of the deformation. This causes abnormal transfer in pit transfer.

FIG. 18 is a schematic cross-sectional view showing a molded substrate and a molding stamper before peeling. FIG. 19 is a schematic cross-sectional view showing a molded substrate and a molding stamper immediately after the start of peeling. 20 is an enlarged cross-sectional view of a portion A in FIG.
In FIG. 18 to FIG. 20, the convex portion 1 b on the lower side of the molding stamper 1 that forms the groove on the molded substrate 7 is sufficiently separated from the molded substrate 7 in the conventional peeled state, but is high to form a pit portion. The convex portion 1a on the side is not sufficiently separated, and when a relative displacement occurs between the molding stamper 1 and the molding substrate 7 in this state, the transfer shape of the pit portion is destroyed, that is, abnormal transfer occurs.
In addition, if the slit width varies, a relative difference occurs between the amount of deformation of the substrate and the holding state of the deformation, resulting in uneven distribution in the region where the abnormal transfer occurs or the extent of the occurrence.
In addition, since compressed air basically flows out selectively from a place with low resistance, in the example shown in FIGS. 15 to 17, if separation occurs in a portion having a wide slit width, the compressed air is not transferred to other portions. As a result, the supply is delayed, and peeling of the entire surface of the molded substrate hardly proceeds. This phenomenon also contributed to the uneven distribution of abnormal transcription.

FIG. 21 is a schematic view showing a molding stamper having a pit portion. FIG. 22 is a cross-sectional view showing a normal pit transfer state along line AA in FIG. FIG. 23 is a schematic view showing a molding stamper having a pit portion. 24 is a cross-sectional view showing a transfer state of the pit portion taken along line BB in FIG. FIG. 25 is a schematic view showing a molding stamper having a pit portion. FIG. 26 is a cross-sectional view showing a transfer state of the pit portion along line CC in FIG.
21 and 22 show a normal transfer state of the pit portion. When peeled in the state shown in FIG. 16, the relative displacement between the forming substrate and the forming stamper becomes relatively large, and the pit portion is transferred as shown in FIGS. Ideally, this is a phenomenon that occurs because the pits of the molding stamper that must be released vertically are released diagonally upward to the right in the drawing.

On the other hand, when the mold is released in the state shown in FIG. 17, the relative displacement between the forming substrate and the forming stamper becomes relatively small, and the pit portion is transferred as shown in FIGS. Either of these results in a transfer state different from the original shape of FIGS.
As is apparent from FIGS. 21 to 26, the laser spot traces the center of the original track in the normal pit transfer state of FIGS. 21 and 22, but in the states of FIGS. For optical reasons, the trace is traced around the right side of the figure.
Even in the state of FIGS. 25 and 26, although there is a difference in the degree of displacement, a portion slightly deviated from the original center to the right side in the drawing is traced as in FIGS. In such a trace state, accurate reading of information is impossible, and the reading reliability of the ROM portion is significantly reduced. From these analyses, the ideal mold release that does not cause abnormal transfer is to shorten the time required for deformation of the molded substrate as much as possible and to move the molded substrate away from the molding stamper in a short time.

As a solution to such a problem, for example, “a method and a molding die of an information recording substrate” described in Patent Document 1 has been proposed. This proposal discloses that a notch is provided in the center portion of the opposing surface of the molding stamper and the molded substrate is lifted by the anchor effect of the notch.
In addition, the “preformat substrate molding method” described in Patent Document 2 and the “preformat substrate molding method” described in Patent Document 3 are provided with minute irregularities on the entire opposing surface of the molding stamper. It has been proposed to lift the molded substrate by the anchor effect.

  However, Patent Document 1 has a problem that local deformation is caused in the inner peripheral portion of the molded substrate, which adversely affects the flatness of the molded substrate. In addition, Patent Document 2 and Patent Document 3 are not ideal methods in that irregularities are provided on the light incident surface of the optical disk substrate, so that irregular reflection or the like is induced on the same surface, leading to a decrease in light use efficiency. It was.

Japanese Patent No. 3558530 JP-A-6-297514 JP-A-6-297515

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention provides a molding die for an optical disk substrate that can be uniformly peeled even if there is a variation in the circumferential width of the annular slit for jetting compressed air in the molding die in releasing the molded product for transferring a fine pattern. It is another object of the present invention to provide a stamper for molding an optical disk substrate, and an optical disk substrate and an optical information recording medium manufactured using these.

Means for solving the above problems are as follows. That is,
<1> Two types of areas, a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing, are mixed in the same plane, and information on the ROM area An optical disk substrate molding die having a molding stamper recorded in a predetermined area,
A molding die for an optical disk substrate, wherein a cavity constituting surface of a mold part on which the molding stamper is placed has a pressure accumulation function means having a temporary pressure accumulation function of compressed air for mold release. is there.
In the molding die for the optical disk substrate according to <1>, the cavity constituting surface of the mold part on which the molding stamper is placed has a pressure accumulating function means having a temporary pressure accumulating function of the compressed release air. Since it is provided, even if there is a variation in the circumference of the annular slit for jetting compressed air in the mold in the mold release for transferring the fine pattern, uniform peeling is possible.
<2> The molding die for an optical disk substrate according to <1>, wherein a cavity constituting surface of the mold part has a stamper holding member.
<3> The molding die for an optical disk substrate according to any one of <1> to <2>, wherein the pressure accumulating function means has a continuous or discontinuous annular convex portion or a continuous or discontinuous annular concave portion.
<4> Two types of areas, a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing, are mixed in the same plane, and information on the ROM area A stamper for molding an optical disk substrate recorded in a predetermined area,
A molding stamper for an optical disk substrate, characterized in that a pressure accumulating function means having a temporary pressure accumulating function of compressed air for mold release is provided on a part of the information forming surface of the molding stamper.
In the molding stamper for the optical disk substrate according to <4>, since a pressure accumulating function unit having a temporary pressure accumulating function of the mold release compressed air is provided on a part of the information forming surface of the molding stamper, Even if there is a variation in the circumference of the annular slit width for compressed air ejection in the mold in the mold release of the molded product to which the fine pattern is transferred, uniform peeling becomes possible.
<5> The pressure accumulation function means is at least one continuous or non-continuous annular convex that is concentric with the center of the information sequence in another area adjacent to the original information area and is not involved in recording and reproducing information. The optical disk substrate molding stamper according to <4>, which has a portion.
<6> The optical disk according to <5>, wherein the height of the cross-sectional shape of the annular convex portion is h1, and the height of the cross-sectional shape of the convex portion carrying predetermined information is h0, and satisfies the relationship of the following formula: h1> h0. A stamper for forming a substrate.
<7> The optical disk substrate molding stamper according to <5>, wherein the cross-sectional shape of the annular convex portion is steeper than the cross-sectional shape of the convex portion carrying predetermined information.
<8> The optical disk substrate molding stamper according to <5>, wherein the cross-sectional shape of the annular convex portion is such that the width of the top is relatively wider than the width of the bottom.
<9> The annular convex portion is formed from a multilayer structure in which a large number of layers containing at least a photosensitive agent are laminated on a glass master, and the sensitivity of the photosensitive agent contained in the lower layer on the side in contact with the glass master in the multilayer structure Is a stamper for molding an optical disk substrate according to <8>, wherein the sensitivity of the photosensitive agent contained in the layer above the lower layer is higher.
<10> An optical disc substrate formed using the molding die for an optical disc substrate according to any one of <1> to <3>.
<11> An optical information recording medium produced using the optical disk substrate according to <10>.
<12> An optical disk substrate formed using the optical disk substrate molding stamper according to any one of <4> to <9>.
<13> An optical information recording medium produced using the optical disk substrate according to <12>.

  According to the present invention, the conventional problem can be solved, and even if there is a variation in the circumference of the annular slit width for compressed air injection of the molding die, the pressure accumulation function in the pressure accumulation function means (accumulation region) eliminates the problem from the molding stamper. It is possible to provide an optical disc substrate molding die and an optical disc substrate molding stamper, and an optical disc substrate and an optical information recording medium manufactured using them.

(Optical substrate molding mold and optical disc substrate molding stamper)
The molding die for the optical disk substrate of the present invention has two types of areas, a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing, in the same plane, and It has a molding stamper in which information relating to the ROM area is recorded in a predetermined area on the inner periphery,
The cavity constituting surface of the mold part on which the molding stamper is placed has a pressure accumulation function means having a temporary pressure accumulation function of the mold release compressed air, and further includes other means as necessary. Become.
The cavity constituting surface of the mold part preferably includes a molding stamper and a stamper holding member.
The pressure accumulating function means preferably has a continuous or non-continuous annular convex part, or a continuous or non-continuous annular concave part, and a continuous or non-continuous annular convex part or a continuous or non-continuous part on the surface of the stamper holding member. It is particularly preferable to have an annular recess.

The stamper for molding an optical disk substrate of the present invention includes a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing in the same plane. Information about the ROM area is recorded in a predetermined area on the inner periphery,
A pressure accumulating function means having a temporary pressure accumulating function of mold release compressed air is provided on a part of the information forming surface of the stamper, and further provided with other means as necessary.
In this case, the pressure accumulating function means is at least one continuous or non-continuous ring that is concentric with the center of the information string in another area adjacent to the original information area and does not participate in the recording and reproduction of information. It is preferable to have a convex part.
When the height of the cross-sectional shape of the annular convex portion is h1, and the height of the cross-sectional shape of the convex portion carrying predetermined information is h0, it is preferable that the relationship of the following formula, h1> h0 is satisfied.
Moreover, it is preferable that the cross-sectional shape of the said annular convex part is steeper than the cross-sectional shape of the convex part which bears predetermined information.
Moreover, it is preferable that the cross-sectional shape of the said annular convex part has the width | variety of the top part relatively wider than the width | variety of the bottom part. In order to form such a cross-sectional shape, the annular convex portion is formed from a multilayer structure in which a large number of layers containing at least a photosensitive agent are laminated on a glass master, and is the side in contact with the glass master in the multilayer structure. It is preferable that the sensitivity of the photosensitive agent contained in the lower layer is higher than the sensitivity of the photosensitive agent contained in the layer above the lower layer.

Now, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing the structure of the inner periphery of a molding die to which the present invention is applied. FIG. 2 is a schematic diagram showing the A portion of FIG. 1 in an enlarged manner. FIG. 3 is a schematic diagram showing the configuration of FIG.

The fundamental problem of the conventional method is that the pressure of the peeling air does not have sufficient pressure and capacity for peeling, and does not work uniformly at the peeling power point. A mold release method proposed to solve this problem is to provide pressure accumulation function means (pressure accumulation region) in the vicinity of the mold release start point of the present invention.
By providing the pressure accumulating function means (accumulated pressure region) in this way, the peeling force that was non-uniform in the circumferential direction until then worked uniformly. The mold capable of accumulating pressure is the mold structure shown in FIG. 1 (enlarged views of main parts are shown in FIGS. 2 and 3). Since the A portion side in FIG. 1 is the inner peripheral portion, in each of the following drawings, the left side of the drawing is the inner peripheral portion or the inner peripheral side.

In FIG. 1, a molding die includes a molding stamper 1, a fixed mirror surface block 2 on which the molding stamper 1 is placed, a stamper holding member 3, an inner sleeve 4 of the stamper holding member 3, The sprue bush 5 is located on the periphery, and a support plate 6 that supports the sprue bush 5.
2 and 3 show that the annular concave portion 3a or the annular convex portion 3b having a pressure accumulation function is continuously or non-circularly formed on the upper surface of the stamper holding member 3 constituting a part of the cavity forming surface of the mold. The case where it provides continuously is shown. Compressed air for peeling the molded substrate from the outer diameter direction via a clearance (clearance between the sleeve 4 and the fixed mirror block 2) between the upper surface of the sleeve 4 and stamper holding member 3 in FIG. 1 and the molded substrate. It is supplied toward the inner diameter and flows in from the left side in the figure.
Naturally, the compressed air is not constant along the circumferential direction and varies, but by using the molding die A provided with the annular recess 3a or the annular projection 3b shown in FIGS. 2 and 3, the annular recess is used. The pressure accumulating structure composed of 3a or the annular convex portion 3b functions, and no separation of the information area occurs until a predetermined pressure is accumulated before the annular concave portion 3a or the annular convex portion 3b (progress from FIG. 4 to FIG. 5 described later). ).

FIG. 4 is a schematic view showing a state before peeling of the molding die using the stamper holding member of FIG. FIG. 5 is a schematic view showing a state immediately after the start of peeling of the molding die of FIG. For this reason, a uniform pressure can be generated in the pressure accumulation region over the entire circumference. 4 and 5, the molding substrate 7 is placed on the molding stamper 1 and the stamper holding member 3.
Since pressure accumulation is possible with a uniform pressure, the pressure accumulated here can be set to a pressure that realizes an ideal peeling state for an information pattern (not shown) formed in the stamper 1.
Conventionally, since the pressure was uneven in the circumferential direction, peeling could not be started almost simultaneously over the entire circumference, and the above setting was impossible. The pressure accumulated in the pressure accumulation region can be adjusted by the shape of the annular concave portion 3a or the annular convex portion 3b formed as the pressure accumulation function means of FIGS.
Although the annular recess 3a or the annular protrusion 3b in the drawing is exaggerated and described in an enlarged manner, the actual size is a minute shape having a width substantially equal to a depth (or height) of several tens of μm. It is. By setting the depth (or height) and width as appropriate in consideration of the information pattern formed on the molding stamper 1, the pressure accumulation limit in the same region can be set.
FIG. 6 is a schematic view showing a state of completion of peeling of the molding die using the stamper holding member of FIG. When separation occurs instantaneously on the inner circumference side from the pressure accumulation region shown in FIG. 5 and the pressure in the pressure accumulation region exceeds the pressure limit set by the above method, the compressed air for separation diffuses all over the separation surface at once, As a result, the peeling of the molded substrate 7 is completed instantly.
In this peeled state, the molding substrate 7 is moved away from the molding stamper 1 without causing unnecessary deformation of the molding substrate 7, so that the abnormal transfer that occurs in the conventional molding method does not occur, and the flatness of the molding substrate 7 is not caused. There is no deterioration.

FIG. 7 is a schematic partial view showing the configuration of the first embodiment of the optical disk substrate molding stamper according to the present invention.
FIG. 8 is a schematic partial view showing the configuration of a second embodiment of a stamper for molding an optical disk substrate according to the present invention.
The optical disk substrate molding stamper 1 of FIGS. 7 and 8 is provided with pressure accumulation function means (pressure accumulation structure) on a part of its information forming surface. The reason why the molding stamper 1 is provided with a pressure accumulating function means (accumulating pressure structure) is employed when it is difficult to give the pressure accumulating function to the structural parts of the molding die as shown in the conventional example of FIG. .

Also in the conventional molding die of FIG. 12, the compressed air for peeling is supplied from the clearance between the sleeve 4 and the fixed mirror block 2. In such a structure, the annular concave portion (convex portion) 2 a which is a pressure accumulating function means (structure having a pressure accumulating function) is directly formed in the fixed mirror surface block 2. In this case, when the annular concave portion (convex portion) 2a is broken for some reason, the mirror block 2 main body is replaced, which requires a large expense for maintenance of the molding die. In this case, it is more efficient to provide pressure accumulation function means (structure having a pressure accumulation function) on the molding stamper 1.
The molding stamper capable of such pressure accumulation is the molding stamper shown in FIGS. As can be seen from both figures, annular convex portions 1c1 and 1c2 that are completely unrelated to the original information are formed on the innermost periphery of the molding stamper 1. These annular convex portions 1c1 and 1c2 form a pressure accumulation function means having a pressure accumulation effect. The basic functions at the same location are the same as those described above.
In the pressure accumulation function means (pressure accumulation function structure) of FIG. 7, an annular convex portion 1 c 1 higher than the original information pattern is formed. Further, the cross-sectional shape of the annular convex portion 1c1 is set steeper than that of the convex portion 1a in the information area (substantially perpendicular to the upper surface of the stamper), thereby achieving an increase in peeling resistance.
Further, the pressure accumulating function means (accumulating pressure function structure) in FIG. 8 has a cross-sectional shape for causing an increase in peeling resistance to function more positively. These shapes are appropriately set according to an uneven pattern of information formed in the information area of the molding stamper 1.

FIG. 9 is a schematic view showing a state before peeling between the molding stamper and the molding substrate according to the present invention. FIG. 10 is a schematic view showing a state immediately after the start of peeling of the forming stamper and the forming substrate according to the present invention shown in FIG. FIG. 11 is a schematic view showing a state after the separation of the molding stamper and the molding substrate according to the present invention of FIG. 9 is completed.
As described above, separation occurs on the inner peripheral side from the pressure accumulation region 1d (see FIG. 10). Thereafter, when the pressure in the pressure accumulation region 1d exceeds the pressure set by the above method, the compressed air for peeling diffuses all over the peeling surface, and as a result, peeling of the molded substrate 7 is completed instantaneously ( FIG. 11). The effect of this peeled state is the same as described above.
The optimum pressure of the peeling air varies depending on the original information pattern formed on the molding stamper 1. A schematic diagram of a two-region mixed stamper of ROM area and recording / reproducing area (recording area and reproducing area) has already been shown in FIGS. 13 and 14 in the description of the prior art. 9 to 11 show a molding stamper 1, a molding substrate 7, and an annular projection-shaped portion 1c1 similar to FIG.
For example, when the pit height in the ROM area is about twice the groove height in the recording / playback area, a pressure of 0.7 MPa was optimal. This pressure is a value that depends on the ratio of the heights of the two, and the pressure can be reduced as the ratio decreases. A pressure of 0.3 MPa was optimum when the heights of the two were almost equal.

In addition, the steepness of the cross-sectional shape of the innermost convex portion of the molding stamper according to the present invention is set steeper than that of the information pattern formed on the outer peripheral side, thereby enhancing the reliability of the pressure accumulation effect. In addition, the two kinds of annular convex shapes 1c1 and 1c2 shown in FIGS. 7 and 8 function to set the pressure for accumulating more reliably. FIG. 7 shows an optimum shape when the accumulated pressure is about 0.3 to 0.5 MPa, and FIG. 8 shows an optimum shape when 0.6 MPa or more is required.
Furthermore, in order to make the pressure accumulation function effectively, it is necessary to optimize the opening speed of the molding die. The jet outlet for supplying compressed air to the pressure accumulation region is a slit of several tens of μm due to restrictions on the mold structure. For this reason, in the case of the low pressure side during the pressure setting described above, the mold opening speed of 3 mm / second, which allows more reliable pressure accumulation, was optimal. In the case of the high pressure side, a speed of 5 mm / second was optimum. When the speed is higher than this, the pressure accumulation does not function, and the molded substrate is equivalent to the conventional quality.
Further, paying attention to the pressure accumulation effect, even if the mold opening speed is set to an extremely low speed (for example, 0.1 mm / second), only the molding time is extended. In some cases, the operation limit of the molding machine may be exceeded, and the mold opening operation itself may be stopped.

  Furthermore, the cross-sectional shape of the annular convex portion shown in FIG. 8 can be produced by the following method. First, a multilayer structure in which a number of layers containing at least a photosensitizer are laminated on a glass master is formed. At this time, among the multilayers, the sensitivity of the photosensitive agent contained in the lower layer that is in contact with the glass master and the sensitivity setting of the photosensitive agent contained in the layer above the lower layer (upper layer) are set as “lower photosensitive agent> It is referred to as “upper layer photosensitive agent”. When exposed in this state, the lower layer is more sensitive than the upper layer, and as a result, the cross-sectional shape of the annular protrusion is relatively wider at the top than at the bottom, as shown in FIG. An annular convex portion having a shape can be formed.

Separation from the inner peripheral portion where a predetermined pressure is accumulated by these methods instantaneously proceeds, and the contact between the molding stamper 1 and the molding substrate 7 at the contact occurrence location shown in the enlarged view of the portion A in FIG. This has the effect that the molded substrate 7 is separated from the molding stamper 1 earlier than the occurrence of the occurrence, and the abnormal transfer does not occur due to the peeled state.
The optical disk substrate in which the ROM area and the recording / playback area obtained by the above molding method are mixed does not have an abnormal transfer area as in the prior art, and the information pattern formed on the molding stamper 1 is accurate. I was able to transcribe.
The optical information recording medium manufactured using the obtained optical disk substrate has high performance with high signal quality because the laser spot can accurately trace the center of the guide groove including the pit row.

  The molding die and molding stamper, the optical disk substrate, and the optical information recording medium of the present invention have been described above. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. It doesn't matter.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
For the optical information recording medium of Example 1 manufactured using the optical disk substrate molded using the molding die shown in FIG. 1, the signal output reproducing the boundary between the ROM area and the recording / reproducing area is observed with an oscilloscope. The results are shown in FIG. FIG. 28 is a diagram schematically showing a reproduction signal of an optical disk substrate having no abnormal transfer as in the first embodiment.
In FIG. 28, the reproduction laser spot is scanned in the direction of the arrow (from left to right) in the figure. The “groove area” in FIG. 28 corresponds to the recording / playback area, and the “pit area” in FIG. 28 corresponds to the ROM area.
From the results of FIGS. 27 and 28, in the optical disk substrate without abnormal transfer as in the first embodiment, there is no shape abnormality in the pit area and the groove area. The region and the groove region were clearly observed. In such a signal state, correct information can be read from the pit area, and information to be written in the groove area can be correctly recorded.

(Comparative Example 1)
With respect to the optical information recording medium of Comparative Example 1 manufactured using the optical disk substrate molded using the molding die shown in FIG. 12, the signal output obtained by reproducing the boundary portion between the ROM area and the recording / reproducing area is observed with an oscilloscope. The results are shown in FIG.
From the results of FIGS. 28 and 29, in the optical disk substrate with abnormal transfer as in Comparative Example 1, there is a geometric abnormality in the pit area and the groove area, so the previous stage of the pit area (see the X part in FIG. 28). Disappears, and an abnormality in output is recognized also in the latter part of the pit area (see the Y portion in FIG. 28). Furthermore, unnecessary noise is also generated in the groove region. Originally, the groove area is linear as shown in FIGS. 27 and 28 of the first embodiment, but in FIG. 29, abnormal areas are recognized at the front and rear ends of the groove area. Note that this signal output includes not only the influence of the shape abnormality of the pit region and the groove region, but also the disturbance of the signal due to the tracking failure (tracking failure) of the reproduction laser spot due to the abnormal shape.
In any case, the signal quality as shown in FIG. 29 deteriorates in the reproduction signal of the optical disk substrate in which abnormal transfer exists as in Comparative Example 1. In such a signal state, correct information cannot be read from the pit area, and even if information is written in the groove area, it cannot be recorded correctly.

  The molding die and the molding stamper according to the present invention provide an optical disk substrate from the molding stamper by a pressure accumulating action in the pressure accumulating function means (pressure accumulating region) even if there is a variation in the circumference of the annular slit width for compressed air injection Therefore, the optical information recording medium can be produced by using the optical disk substrate.

FIG. 1 is a schematic view showing an example of the structure of the inner periphery of a molding die for an optical disk substrate according to the present invention. FIG. 2 is a schematic diagram showing the A portion of FIG. 1 in an enlarged manner. FIG. 3 is a schematic diagram showing the configuration of FIG. FIG. 4 is a schematic view showing a state before peeling of the molding die using the stamper holding member of FIG. FIG. 5 is a schematic view showing a state immediately after the start of peeling of the molding die of FIG. FIG. 6 is a schematic view showing a state of completion of peeling of the molding die using the stamper holding member of FIG. FIG. 7 is a schematic partial view showing the configuration of the first embodiment of the optical disk substrate molding stamper according to the present invention. FIG. 8 is a schematic partial view showing the configuration of a second embodiment of a stamper for molding an optical disk substrate according to the present invention. FIG. 9 is a schematic view showing a state before peeling between the molding stamper and the molding substrate according to the present invention. FIG. 10 is a schematic view showing a state immediately after the start of peeling between the molding stamper and the molded substrate according to the present invention. FIG. 11 is a schematic view showing a state after the peeling of the molding stamper and the molded substrate according to the present invention is completed. FIG. 12 is a schematic view showing the structure of the inner periphery of a conventional molding die. FIG. 13 is a schematic plan view showing a two-region mixed stamper used for manufacturing a substrate. 14 is a schematic cross-sectional view taken along line AA in FIG. FIG. 15 is a schematic diagram showing a slit width variation state. FIG. 16 is a schematic diagram showing a peeled state of portion A of FIG. 15 in a conventional molding die. FIG. 17 is a schematic view showing a peeled state of a portion B in FIG. 15 in a conventional molding die. FIG. 18 is a schematic cross-sectional view showing a molded substrate and a molding stamper before peeling. FIG. 19 is a schematic cross-sectional view showing a molded substrate and a molding stamper immediately after the start of peeling. 20 is an enlarged cross-sectional view of a portion A in FIG. FIG. 21 is a schematic view showing a molding stamper having a pit portion. FIG. 22 is a cross-sectional view showing a normal pit transfer state along line AA in FIG. FIG. 23 is a schematic view showing a molding stamper having a pit portion. 24 is a cross-sectional view showing a pit portion transfer state along line BB in FIG. FIG. 25 is a schematic view showing a molding stamper having a pit portion. 26 is a cross-sectional view showing a pit portion transfer state along line CC in FIG. FIG. 27 is a diagram in which the reproduction signal output when there is no abnormal transfer in Example 1 is observed with an oscilloscope. FIG. 28 is a schematic diagram when the reproduction signal output when there is no abnormal transfer is observed with an oscilloscope. FIG. 29 is a diagram of the reproduction signal output observed with an oscilloscope when there is an abnormal transfer in Comparative Example 1. FIG.

Explanation of symbols

1 Molding stamper 1a Pit part (ROM area)
1b Recording / playback area 1c1 First embodiment of protrusion-shaped part not related to information 1c2 Second embodiment of protrusion-shaped part not related to information 1d Pressure accumulation area 2 Mold part (fixed mirror block)
3 Stamper holding member 3a Annular recess 3b Annular projection 4 Mold part (sleeve)
7 Molded substrate (optical disk substrate)
A Mold

Claims (13)

Two types of areas, a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing, coexist in the same plane, and information relating to the ROM area is a predetermined area on the inner periphery A molding die of an optical disk substrate having a molding stamper recorded in
A molding die for an optical disk substrate, characterized in that a cavity constituting surface of a mold part on which the molding stamper is placed has pressure accumulation function means having a temporary pressure accumulation function of compressed air for mold release.   2. The molding die for an optical disk substrate according to claim 1, wherein a cavity constituting surface of the die part has a stamper holding member.   3. The molding die for an optical disk substrate according to claim 1, wherein the pressure accumulating function means has a continuous or non-continuous annular convex portion or a continuous or non-continuous annular concave portion. Two types of areas, a read-only ROM area and a recording / playback area capable of at least one of recording, reproduction, and erasing, coexist in the same plane, and information relating to the ROM area is a predetermined area on the inner periphery A stamper for molding an optical disk substrate recorded in
An optical disk substrate molding stamper comprising pressure accumulation function means having a temporary pressure accumulation function of compressed air for mold release on a part of an information forming surface of the molding stamper.   The pressure accumulating function means has at least one continuous or non-continuous annular convex portion that is concentric with the center of the information sequence in another area adjacent to the original information area and does not participate in recording and reproduction of information. The stamper for molding an optical disk substrate according to claim 4.   6. The optical disk substrate for forming an optical disk substrate according to claim 5, wherein the height of the cross-sectional shape of the annular convex portion is h1 and the height of the cross-sectional shape of the convex portion carrying predetermined information is h0. Stamper.   6. The stamper for molding an optical disk substrate according to claim 5, wherein the cross-sectional shape of the annular convex portion is steeper than the cross-sectional shape of the convex portion carrying predetermined information.   6. The stamper for molding an optical disk substrate according to claim 5, wherein the cross-sectional shape of the annular convex portion is such that the width of the top is relatively wider than the width of the bottom.   The annular convex portion is formed from a multilayer structure in which a plurality of layers containing at least a photosensitive agent are laminated on a glass master, and the sensitivity of the photosensitive agent contained in the lower layer on the side in contact with the glass master of the multilayer structure is 9. The stamper for molding an optical disk substrate according to claim 8, wherein the sensitivity of the photosensitive agent contained in the upper layer is lower than that of the lower layer.   4. An optical disk substrate, which is molded using the molding die for an optical disk substrate according to claim 1.   An optical information recording medium manufactured using the optical disk substrate according to claim 10.   10. An optical disk substrate formed by using the optical disk substrate molding stamper according to claim 4. An optical information recording medium manufactured using the optical disk substrate according to claim 12.