JPH11333856A - Manufacture of molding tool for resin board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mass-produce sons of little skin roughness from one matrix by a method wherein a first molding tool made of metal is prepared, a second molding tool made of resin is formed of the first molding tool and a third molding tool made of metal is formed of the second molding tool. SOLUTION: A matrix II is obtained by exposing and developing a photoresist 2 of a synthetic silica board 1 and by removing the remaining resist. An Ni plating layer 3 is formed on the surface of the matrix II and exfoliated from the matrix II and thereby a father is obtained. Then, a resin liquid is dropped on the father with the indentation up and pressed by a glass disk 5 so that the resin liquid being viscous be expanded evenly on the whole surface of the father. Next, ultraviolet rays are cast through the glass disk 5 to cure the resin liquid and thereby a mother having a two-layer structure of a hard resin layer 4 and the glass disk 5 is obtained. A son 6 is manufactured from this mother being exfoliated, by the same manufacturing method as that for the father. A free son 6 is obtained by exfoliating that son 6 from the mother. A protective coat is provided on the indented surface of the son 6 and then the surface is ground to have a uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a molding die and a method for manufacturing a resin substrate. The molding die is used for molding a resin substrate having fine irregularities. Such a resin substrate is used for an optical disk, a magnetic disk, a hard disk, and other uses.

[0002]

2. Description of the Related Art An information recording medium such as an optical disk or a hard disk can record a large amount of information and can access, reproduce, record, and (in some cases, erase) at high speed. Therefore, these media are C
D (compact disc), LD (laser disc), DVD (dig
It is used as a medium for storing music, video software, game software, and the like, and its demand is increasing. These media are also used as computer memories, and their demand is increasing. Optical disks and hard disks are expected to greatly develop as main memories in the multimedia age.

In the case of an optical disk, (1) a read-only type (CD, L
D, CD-ROM, photo-CD, DVD-ROM, read-only type MD, etc.) (2) Write-once type (CD @ R, DVD-R, D
VD-WO, etc.), (3) rewritable type that can be erased after recording and can be rewritten many times (magneto-optical disk, phase change
change) type disc, MD, CD-E, DVD-RA
M, DVD-RW, etc.). Furthermore, a high-density HD-DVD has been proposed as a medium to be used in the future.

[0004] The process of manufacturing these optical disks starts with molding a resin substrate with a raw material resin.
First, a mold called a stamper is prepared. A resin substrate is molded (manufactured) by heating and fluidizing a raw material resin (for example, polycarbonate, acrylic resin, polystyrene, or the like) into the molding die and pressing the resin. The molding method is injection molding in addition to pressure molding.

The reason why a resin substrate is manufactured is that fine irregularities are required on the substrate surface. The only way to produce a large number of irregular substrates in a short time is through resin molding. The types of unevenness are (1) a pit pit representing an information unit and (2) a guide groove for tracking of a recording head (pickup). The pits and grooves are provided concentrically or spirally on a circular substrate. When viewed in the radial direction, the space between the grooves is called a land. Initially, the land recording method used a land as a track and recorded there. Conversely, there is also a groove recording method for recording in grooves.

In order to improve the recording density, a land / groove recording method for recording data on both grooves and lands has been developed. in this case,
Both are tracks, and the width of the groove is almost equal to the width of the land. However, the other may be intentionally widened for a reason. Light is incident on the substrate from the back surface (smooth surface). When viewed from the substrate side, the back side is called a land, and the front side is called a groove.

The widths of the grooves, lands and pits are, for example, 1 μm or less, 0.8 μm or less, as the density recording is improved.
0.7 μm or less, 0.6 μm or less, 0.5 μm or less,
It has become narrower than 0.4 μm and 0.3 μm. The depths of the grooves, lands and pits are also increased with high-density recording, for example, 40 nm or more, 50 nm or more, 80 nm or more, 100 nm or more, 120 nm or more, 130 nm or more, 150 nm or more, 180 nm or more, 200 nm or more, 220 nm or more, 250 nm or more. It is getting deeper.

When the width becomes narrow or the depth becomes deep, that is, when the precision becomes high, the molding of the resin substrate becomes more and more difficult, and the yield of non-defective products decreases. Note that a reflective layer, a recording layer, a protective layer, and the like are formed on the molded resin substrate according to the final product. In addition, the hard disk usually has a magnetic recording layer formed on an aluminum substrate or a glass substrate. Recording is performed with a magnetic head. As the density increases, the surface of the recording layer becomes extremely smooth. Therefore, when the magnetic head stops relatively, a phenomenon occurs in which the head and the recording layer come into close contact and cannot be separated. To avoid this, the hard disk has a garage area (CSS area = co
ntact stop and start). The surface of this region is botherged with a laser texture. The unevenness prevents adhesion.
In addition, with high density, tracking of the head becomes difficult. Therefore, it has been proposed to provide a groove in the disk, as in the case of the optical disk. Since unevenness and grooves are required as described above, a resin substrate has been proposed to increase the productivity of the disk. Even in a hard disk, a resin substrate is used, and irregularities and grooves are formed when the substrate is molded. The resin substrate also has the advantage of being light.

Conventionally, a molding die is generally manufactured by the following process (see FIG. 3B, and FIG. 3A is a second embodiment of the present invention). As an old prior art, US Pat. No. 4,211,617 (corresponding Japanese patent = publication S59-
16332). First, a glass substrate (1) polished to optical surface accuracy is prepared. After washing the substrate, a primer (for example, a silane-coupling agent) for improving adhesion is applied. Then spin coat photoresist photoresist,
Pre-bake. (Refer to (B1) of FIG. 3) As a photoresist, a positive type (a type in which a portion irradiated with light is removed by development) is often used. Next, laser
The photoresist is exposed according to the pattern of the pits and grooves using a laser-beam-recorder or a laser cutting machine. Generally, the diameter of a laser beam determines the width of a pit or groove.
Generally, the depth of the pits and grooves is determined by the thickness of the photoresist.

[0010] Next, when developed, a resist pattern resist having a pit or groove pattern on the surface of the glass plate.
The pattern is obtained. After development, the resist pattern optionally undergoes a post-bake at 80-120 ° C for 20-60 minutes. If post-baking is performed, wait for the resist pattern to cool to room temperature. About 1
Wait 0 hours. This is shown in FIG. 3 (B2).

The resist pattern is a master (MASTER SUBSTR)
ATE or MASTER). In this specification, this master is referred to as master I. Master I corresponds to the replica replica 46 of FIG. For example, consider a case where a resist pattern for a CD is manufactured. In this case, it takes 74 minutes to complete the exposure. In the case of post-baking, it takes about 10 hours or more to complete the master I after all.

In addition, a laser beam recorder or a laser cutting device is expensive at about 200 million yen per unit. Therefore, the master I is expensive and mass production is difficult. Next, the master is subjected to a conductive treatment. The conductive treatment is generally performed by sputtering (dry method), or in some cases,
It is performed by electroless plating (wet method). A thick plating layer is formed on the master I that has been made conductive. The plating layer is generally nickel (Ni). 2 of conductive layer and Ni plating layer
The layer structure is the intended first mold. This is shown in FIG. 3 (B3). This first mold is a father (FAT
HER). Actually, a free father can be obtained by peeling the father from the resist pattern (master). This is shown in FIG. 3 (B4). Father is a mother member of FIG.
mber) 52.

The father is generally as thin as 200 to 300 μm, so care is taken when peeling it. When the resist is peeled off, a part of the resist remains on the father. Therefore, the resist is dissolved and removed with a solvent such as acetone. If the resist remains, the unevenness is broken, so that the resist is surely removed. When peeled, the resist pattern is damaged, so that only one father is obtained from one master.

After removing the resist, the uneven surface of the father is covered with a protective coat. Then, the back surface is polished. The center hole of the father is punched out, and unnecessary parts outside the outer diameter are shot down. This completes the donut-shaped father. The father thus completed has a very accurate concavo-convex pattern. And it is expensive. The reason for the high cost is that (1) the master I is expensive and (2) only one father can be obtained from one master.

The father can be used as it is in a mold for resin molding. Rather, DVD @ RA
In the case of M, MD, HD @ DVD and other high-density recording media (groove width 0.8 μm or less), a very high-precision uneven pattern is required. However, as mentioned, fathers are extremely expensive. Therefore, the father is used in place of the master and Ni electroforming is performed in the same manner to obtain a duplicate (second molding die). This is shown in FIG. 3 (B5). This second mold is called a mother (MATHER). In fact, a free mother can be obtained by removing the mother from the father. This is shown in FIG. 3 (B6). Mother states that
This corresponds to the submaster 60 in FIG.

To facilitate the removal of the mother, the father is surface-treated before electroforming. For the treatment, a potassium dichromate solution, a potassium permanganate solution, or the like is used.
This process is called passivation. The father cannot be used over and over again because the father is slightly damaged when the mother is peeled from the father. At most 2-3 times. Therefore, only two or three mothers can be obtained from one father. The mother may be used as it is for injection molding.

In order to further increase the number of copies or invert the concavities and convexities, a mother is used in place of the master and Ni electroforming is performed in the same manner to obtain a copy (third mold). This is shown in FIG. 3 (B7). The third mold is called Sun (son SON). In fact, peeling off the sun from the mother gives you a free sun. This is shown in FIG. 3 (B8). Sun corresponds to the stamper member 70 in FIG.

To facilitate the peeling of the sun, the mother is passivated before electroforming. Also in this case, the mother cannot be used again and again because the mother is damaged when the sun is peeled from the mother. At most 2-3 times. Therefore, only two or three suns can be obtained from one mother. After all, only 2 × 2 × 3 × 3 = 4 to 9 suns can be obtained from one expensive father.

Usually, a large number of resin substrates are molded by injection molding using a sun (father or mother, depending on the case). This substrate is used as a material of an information recording medium such as an optical disk or a hard disk. About 20,000 to 30,000 resin substrates can be formed from one sun. But beyond that, the sun is broken and unusable. Even if used, the quality of the resin substrate deteriorates.

Information recording media are now sold to end users for one hundred yen (in the case of CD-R), and increasingly low-cost media are being demanded. Along with this, Sun is also required to be supplied in large quantities at low cost.

[0021]

In the case where a highly accurate concave and convex pattern is required, there is a problem A that a father is used, which is expensive. To reduce the price, even if Sun is duplicated, the number is still small (4 to
9). Therefore, Sun is still expensive (Problem B). In addition, mass production is also difficult (problem C).

In order to lower the price, it has been proposed to manufacture a large number of mothers from one father or a large number of suns from one mother. However, then, the obtained large amounts of mother and sun do not have high accuracy (problem D). In addition, a large number of similar fathers are required, and when a large number of fathers are manufactured, a subtle difference inevitably occurs between the fathers (problem E). This subtle difference is called personality here. Due to the individuality, it is necessary to finely adjust the molding conditions (eg, mold temperature, injection pressure) of the injection molding every time the father is replaced. Similarly, an adjustment is required between mothers and between suns.
Adjustment is required between the father and the mother, between the mother and the sun, and between the father and the sun (problem E). Injection molding companies are very reluctant to personalize, since the adjustment time reduces the productivity of the substrate (Problem F).

It is an object of the present invention to overcome or mitigate one or more of these problems.

[0024]

SUMMARY OF THE INVENTION Accordingly, the present invention firstly provides a process for preparing a first metal mold and forming a second resin mold from the first mold. And a step of forming a third metal mold from the second mold. A method for manufacturing a resin substrate mold (first invention).

Further, the present invention provides a method wherein the first molding die is
A method of the first invention (second invention), characterized by being "a product produced by an electroforming method using a predetermined resist pattern (master I)". The present invention is further characterized in that the first mold is "a ceramic mold having a predetermined concavo-convex pattern and manufactured by an electroforming method (master II)". Method (third invention) ".

The present invention is further characterized in that the ceramic mold is "manufactured by etching a ceramic substrate on which a predetermined resist pattern is formed, and then removing the remaining resist." Of the third invention (fourth invention). " The present invention further provides:
"The method according to the third or fourth invention, wherein the ceramic is quartz (fifth invention)" is provided.

The present invention further provides a method according to the first invention, characterized in that the second step is repeated by repeatedly using the first molding die to thereby form a plurality of second molding dies ( 6th invention) ". The present invention further provides:
"The method of the first invention (the seventh invention) characterized in that the second step is repeated by repeatedly using the same first molding die, thereby forming 20 or more second molding dies." provide.

The present invention further provides a method according to the first invention, wherein the first mold has a surface roughness Ra of 10 nm or less, and the second mold has a surface roughness Ra of 10 nm or less. (Eighth invention) ". The present invention further provides a method according to the first invention, wherein the second mold has a surface roughness Ra of 10 nm or less, and the third mold has a surface roughness Ra of 10 nm or less (the ninth method). Invention)].

According to the present invention, there is further provided a method for manufacturing a semiconductor device comprising the steps of: "the first mold has a surface roughness Ra of 1 nm or less;
a is also 1 nm or less, the method of the first invention (10th invention) "is provided. The present invention further provides a method according to the first invention, characterized in that the second mold has a surface roughness Ra of 1 nm or less, and the third mold has a surface roughness Ra of 1 nm or less (11th invention). Invention)].

According to the present invention, there is further provided a liquid crystal display device comprising: the first molding die, wherein the resin constituting the second molding die is a thermosetting resin.
Method of the Invention (Twelfth Invention) ". The present invention further provides a method according to a twelfth invention, wherein the thermosetting resin is a radiation-curable resin, and the second mold is made of a resin cured by irradiation with radiation. (A thirteenth invention).

The present invention further provides a method according to the first or second aspect, wherein the resin constituting the second mold is a resin that does not adhere to the first mold and / or the third mold. The method of the twelfth or thirteenth invention (the fourteenth invention) "is provided. The present invention further provides "the method of the first to fourteenth inventions (fifteenth invention), wherein the molding die is a mold for molding a resin substrate for an information recording medium".

The present invention further provides a method for producing a resin substrate for an information recording medium from a raw material resin by an injection molding method using a molding die produced by the method of the first to fourteenth inventions (a sixteenth invention). "I will provide a. The present invention further provides a method for manufacturing a resin-made mold, comprising: a step of preparing a first metal-made mold; and a step of molding a second resin-made mold from the first mold. Method (17th invention) ".

According to the present invention, further, “surface roughness Ra is 1 nm
The following third metal mold (the eighteenth invention) is provided. The present invention further provides "a third metal mold having a surface roughness Ra of 0.5 nm or less (a nineteenth invention)." The present invention further provides a "third metal mold (twentieth invention) having a surface waviness Wa of 1 nm or less".

The present invention further provides a method of “wavines
s) Third metal mold having Wa of 1 nm or less (20th invention) "
I will provide a. The present invention further provides an “effective diameter of 50 to 13
0 mm resin substrate, surface waviness Wa is 1 nm
The following molded resin substrate (the twenty-first invention) is provided.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below.
This is not a limitation of the present invention. In the present invention, the master
(MASTER) is roughly classified into type I and type II. Both are sometimes referred to collectively as "masters". [Master I] First, a substrate substrate is prepared. Generally, the substrate has a disk shape, but is not limited to a disk shape, and may be a square shape. Substrate materials mainly include soda lime glass (blue plate glass), aluminosilicate
Glass materials such as glass (white plate glass), alkali-free glass, low expansion glass, crystallized glass, and ceramic materials are used. The ceramic material may be quartz such as fused quartz or synthetic quartz, or Si. In some cases, the substrate material may be a metal such as Al, Fe, or Cu.

The surface of the substrate is precisely polished to obtain a high-precision surface accuracy (smooth surface). A surface layer may be formed on the substrate surface. As the material of the surface layer, (1) SiO2
A surface layer may be formed on the plate surface as described above. As the material of the surface layer, (1) Si oxide such as SiO ₂ , (2) Si oxide
Si nitride such as ₃ N ₄ , (3) Si metal compound such as TiSi ₂ , or (4) Ti, Al, Cu, C
metals such as r, Ta, Au, Ag, Pt, or (5) T
iO ₂ , TiN, Al ₂ O ₃ , AlN, TaO ₂ , Ta
Examples include metal oxides and metal nitrides such as ₂ O ₅ and Ta ₃ N ₄ . The surface layer may be formed by oxidizing or nitriding the substrate surface. In many cases, the surface layer is formed by a thin film laminating technique (eg, vacuum deposition, sputtering). In that case, the surface layer may have a multilayer structure in which two or more of the above materials are combined and laminated. The surface layer is formed by CMP (chem.
ical mechanical polishing) or other methods.

Next, a photoresist is applied to the surface of the substrate. Generally, a primer primer such as a silane coupling agent is applied to the substrate before applying the photoresist. The primer improves the adhesion between the substrate and the photoresist. However, when Cr, TiN, or the like is present in the surface layer, a primer may not be necessary. And
A photoresist is applied by a method such as spin coating. Generally, the thickness of the photoresist determines the depth of the pits and grooves.

The widths of the grooves, lands and pits are, for example, 1 μm or less, 0.8 μm or less, as the density recording is improved.
0.7 μm or less, 0.6 μm or less, 0.5 μm or less,
It has become narrower than 0.4 μm and 0.3 μm. The depths of the grooves, lands and pits are also increased, for example, by 40 nm or more, 50 nm or more,
As described above, the depth has increased to 100 nm or more, 120 nm or more, 130 nm or more, 150 nm or more, 180 nm or more, 200 nm or more, 220 nm or more, and 250 nm or more.

After the photoresist is applied, a pre-bake is performed at a low temperature to adjust the resist sensitivity. Then, use a laser beam recorder to record pits, grooves and other patterns.
The resist is irradiated with a laser beam along the pattern. This exposes the resist. Next, the exposed resist is immersed in a developer and developed. The developer is an inorganic alkali solution such as sodium phosphate, potassium phosphate, sodium hydroxide, potassium hydroxide and the like. An organic alkali solution can be used instead of inorganic. If the photoresist is positive, the exposed portions dissolve in the developer. In the case of the negative type, the unexposed portions dissolve in the developer. Thereafter, the resist is washed with ultrapure water. In the melted portion, the underlying substrate is exposed.

Thus, the photoresist pattern is formed on the surface.
A substrate having a pattern is obtained. In the present specification, such a substrate is referred to as a resist pattern including the substrate. This resist pattern is the master I. The master may be post-baked at a slightly higher temperature after development. In some cases, the post-baking makes the angle of the side wall of the formed groove or pit sharp. Further, the etching resistance of the resist can be improved. Further, the post bake can also improve the adhesion between the resist and the substrate. Post baking may increase the hardness of the resist surface. If the hardness increases, when forming a conductive film thereafter, or when further forming a plating layer by electroforming on it,
Resist can withstand them.

When a resin substrate is injection-molded using a third mold (sun), it is preferable that (1) the side wall angle of the groove or pit is inclined, or (2) the side wall shape is rounded. The transferability and the releasability may be good. [Master II] First, a master I (resist pattern) is prepared. Since the substrate is exposed in a part of the resist, the exposed portion is etched to provide a concave portion in the substrate. This concave pattern is the same as the pattern of the resist.

The etching method may be a wet process, but a dry process is preferred. Among dry etching, especially reactive ion etching (RIE)
Is valid. In addition, etching using magnetron RIE, ECR (Electron Cyclotron Resonance), ICP (Inductively Coupled Plasma), helicon wave, or the like can be used. The RIE may be a normal low plasma density (about 10 ¹⁰ / cm ³ or less) process. However, in order to reduce the roughness of the etched portion and the roughness of the side wall, a process with a high plasma density (about 10 ¹¹ cells / cm ³ or more) is preferable. ICP, R using helicon wave
IE. The latter is effective when the pattern becomes finer.

With dry etching,
The sidewall angles at the front end and the rear end of the pit can be made steep. Therefore, the reproduction signal jitter (jitter) of the optical disc
Is reduced. The ceramic type (master II) has less rough pits and groove side walls than the resist pattern (master I). In the case of dry etching, the surface roughness of the bottom surface and the side wall of the concave portion is extremely small even after the etching. Dry etching can also form recesses with steep sidewall angles. The etching is not limited to the dry method, and the etching can form a deeper concave portion. The fact that the recess is deep and the sidewall angle of the recess is steep brings various advantages to the optical disc. Benefits include noise reduction, optical cross-talk between adjacent tracks, and thermal cross-talk.
l There is a reduction in cross-talk (= cross-erase).

When a substrate having a surface layer is used, only the surface layer may be etched. In this case, if the material of the surface layer and that of the substrate as the base are different, the etching rate is also different, so that there is an advantage that the end points of the etching can be aligned. In this case, the thickness of the surface layer determines the grooves and other depths. After the etching, the remaining resist is removed. Removal is possible by dry etching (ashing) using oxygen plasma.
Alternatively, the remaining resist can be removed by immersing it in “a heated solution of a concentrated acidic solution (for example, concentrated sulfuric acid or concentrated nitric acid)”. It is effective to add aqueous hydrogen peroxide to the solution. After removing the resist in this manner, the substrate surface is washed with ultrapure water or the like.

As a result, a substrate having concave portions corresponding to pits and grooves can be obtained. This substrate is the master disk II. The substrate material is particularly preferably ceramics. This is because ceramics have a very smooth surface (skin). That is, the surface roughness Ra of the ceramic is extremely small (Ra ≦ 10 nm, and in some cases, Ra ≦ 10 nm).
m). This lowers the noise of the optical disk when the optical disk is manufactured. Therefore, in honor of ceramics, the master disk II may be referred to as a ceramic mold in this specification.

[First Mold (Father)] First, a master is prepared. Father plating the master (thick film method)
It is manufactured by The plating layer becomes the father. Plating includes dry and wet plating. Wet methods include electroless plating and electrolytic plating. The dry method is called a vacuum thin film forming technique. Vacuum deposition, ion plating,
There are sputtering and the like. The first method involves dry and electroless plating. The second method is electrolytic plating. The plating is performed by the first method or the second method.

The second method (electrolytic plating) uses electroforming.
Also called forming. Electroforming can form a thick plating layer in a short time. In the case of electroforming, since the master has no conductivity, a thin surface (generally, about 5
(0-100 nm) Metal layer is formed. The metal layer is called a conductive layer, and this formation is called a conductive treatment. The conductive treatment is performed by the first method. The metal is preferably Ni (nickel), and in addition, Au, Pt, Pd, Ag, Ti,
There are Ta, Cr and the like. In addition, metals having high conductivity and metal compounds thereof can be used. Further, the metal may contain phosphorus. When using Ni as the metal, N
Another metal or metal compound having a thermal expansion coefficient close to or equal to i may be formed as the second primer layer. A conductive layer is formed on the second primer layer. The second primer layer can reduce "a phenomenon in which the electroformed layer is distorted by stress" during or after the electroforming. This phenomenon sometimes destroys concave portions such as pits and grooves. The second primer layer is optionally removed after the father is completed.

Thereafter, the master on which the conductive layer is formed is immersed in a plating bath for electroforming. For the plating bath, a nickel sulfamate solution is often used. When electroforming is performed, a Ni plating layer is formed on the conductive layer. This Ni plating layer is a father (first molding die). Other metals can be used instead of Ni. Or,
Ni may be mixed with another metal such as Ti or an element such as P (phosphorus). If Ti is mixed, a mold that is relatively strong and has good durability can be obtained. If P is mixed, a mold having a high surface hardness may be obtained. Ni-P, Ti-P, Ni-Ti-P
By using such an alloy, it is possible to obtain a high hardness and high durability father.

Also, instead of a single Ni plating layer, Ni
A multilayer structure in which another plating layer (for example, a metal such as silver, copper, or chromium, or an alloy thereof) is stacked in addition to the plating layer may be used. In some cases, without using electroforming,
It is also possible to manufacture a metal father (first molding die) by the first method (dry or electroless plating method). The dry method has no problem of treating the plating solution waste liquid. Of the dry processes, ion plating can give molds with particularly low surface roughness.

The thickness of the formed plating layer is about 100 μm
Is exceeded, the irregularities of the master no longer appear on the surface. That is,
When viewed from the outside, the surface of the plating layer is flat. The thickness of the plating layer is about 200 to about 600 μm (generally about 2 to
When the thickness reaches 50 to about 300 μm, the plating is stopped. This completes the father. Immediately after completion of the father (first molding die), the father is peeled off from the master because it is attached to the master. Since the father is a thin metal film, care must be taken to remove it. After peeling, the father is washed because there is a possibility that a resist, a primer and other stains are attached to the surface of the father. For cleaning,
There are (1) a wet type using an organic solvent or ultrapure water, and (2) a dry type such as ashing, plasma treatment, UV irradiation, ozone cleaning and the like.

The process up to this point is described in US Pat. No. 5,673,250 (corresponding Japanese patent = public Koukai H8).
-22621), column 11, line 56 to column 12, line 39 and FIG. 9 also provides some explanation. [Second Mold (Mother)] In brief, the mother is made as follows. A soft resin is pressed against the uneven surface of the father, and then the resin is hardened or cured. The solidified or cured resin has transferred the irregularities of the father and is peeled off from the father. The peeled resin is a mother or a second mold (duplicate mold). That is, the mother is made of resin. This is one of the features of the present invention. In this respect, it differs from prior art metal mothers.

A major difference from the prior art is that after a mother is manufactured from one father, the father can be reused many times. In the prior art, the father can be reused at most three times. With the present invention,
Can be reused 10,000 times or more. Another difference is that a plurality of mothers manufactured from one father have no personality compared with each other. That is, their mothers are exactly the same (clone). Therefore, when a metal sun (third molding die) is manufactured using each mother, the obtained suns are clones of each other.

The resin used for pressing against the father is preferably a resin having high transferability. Those having low viscosity and high fluidity generally have high transferability. To lower the viscosity,
(1) There is a method of softening by heating. In this case, if the resin is cooled, it solidifies. Alternatively, (2) a solvent may be mixed with the resin. In this case, if the solvent is volatilized, the resin solidifies. Further, (3) the low molecular weight resin or prepolymer prepolymer or resin raw material has low viscosity. Extremely liquid. These may be mixed with a solvent. If the solvent is mixed, the viscosity becomes even lower. In this case, a solid resin (high-molecular-weight resin) is generated if the polymerization (for example, curing) of the mother surface is advanced. The generated resin transfers the unevenness of the mother.

Particularly, the method (3) is preferred. The means for promoting the polymerization by the method (3) is (a) heating or (b) irradiation. Alternatively, there is also a means (c) in which two resin liquids are mixed and reacted with each other simply by being left alone to polymerize.
Examples of the radiation include an ion beam, an electron beam, ultraviolet light, far ultraviolet light, a laser beam, X-ray, and synchrotron radiation. Above all, ultraviolet light would be easy to handle.

A preferred method will be described. Since the father is thin (generally about 250 to 300 μm), the flatness is poor. Therefore, it is preferable to first back the father with a highly planar substrate. The substrate is metal or glass. Examples of the metal include iron, copper, brass, aluminum, stainless steel, and bronze. The thickness of the substrate is about 1 to 20 mm. The substrate is bonded to the father with an adhesive.

The father is placed with the uneven surface facing upward. A low-viscosity radiation-curable resin liquid is dropped from above. A transparent plate (generally a glass plate) is placed on the resin solution so that bubbles do not enter. Radiation is irradiated through the transparent plate to cure the resin. The cured resin is peeled off from the father together with the transparent plate. In this way, a mother having two layers of a cured resin and a transparent plate is obtained.

The thickness of the glass plate as the transparent plate is 0.6
mm or more, preferably about 4 mm to about 10 mm. The surface roughness of the glass plate may be lower than that of the master substrate.
The surface roughness Ra may be from 5 nm to 1 μm. Instead of a glass plate, resins such as polycarbonate, polystyrene, polyolefin, and acrylic resin can be used. When a glass plate is used, after washing in advance, a third primer for improving the adhesion to the resin may be applied. After application, it is preferable to bake by heating. An example of the third primer is a silane coupling agent.

Examples of the silane coupling agent include vinyl silane, acrylic silane, epoxy silane, amino silane and the like. Examples of vinylsilane include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, and the like.Acrylic silanes include γ-methacryloxypropyltrimethoxysilane, and epoxy silane. β- (3,4 epoxycyclohexyl)
There are ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethyldiethoxysilane and the like, and as aminosilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (Aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane and the like. In addition, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like are also used.

Examples of other primers are silane (eg, chlorosilane, alkoxysilane), silazane and special silylating agents. These primers may be used as a mixture of two or more. The primer may be used after being diluted with a solvent such as toluene, xylene, ethyl alcohol, methyl alcohol, or isopropyl alcohol. For example, the following resins can be used as the mother resin. When roughly classified, there are (1) a thermoplastic resin and (2) a thermosetting resin.

(1) Thermoplastic resin: polycarbonate,
Polystyrene, styrene polymer alloy, polyolefin, polyethylene, polypropylene, amorphous polyolefin, acrylic resin (for example, polymethyl methacrylate), polyvinyl chloride, thermoplastic polyurethane, polyester, nylon, etc.

(2) Thermosetting resin: thermosetting polyurethane, epoxy resin, unsaturated acrylic resin, acrylic urethane resin, unsaturated polyester, diethylene glycol bisallyl carbonate resin and the like. A resin obtained by curing a resin liquid containing a urethane-containing poly (meth) acrylate, polycarbonate di (meth) acrylate, or acetal glycol diacrylate as a main component is also preferable.

In the case of a thermosetting resin, a low molecular weight resin liquid is used when the thermosetting resin is brought into contact with the father. The resin liquid may include a curing catalyst or a curing agent. When curing with ultraviolet light, a photosensitizer is used as a curing catalyst. Representative photosensitizers include acetophenones, benzoin alkyl ethers, propiophenones, ketones, anthraquinones, and thioxanthones. A plurality of types may be mixed and used. In particular, ketone-based 1-hydroxycyclohexyl phenyl ketone and the like are useful in terms of transfer performance, release performance, and quality stability. UV curable resins are especially UV curable (curabl
e) Called resin. These resins are preferred as mothers.

Particularly, when the mother is peeled off, a resin which does not adhere to the father or the sun is preferable. An antistatic agent may be mixed with the resin solution for measures against static electricity in the subsequent electroforming step or ion plating step. Alternatively, a thin antistatic layer (for example, a Pt layer) may be formed after the mother is completed. Such measures prevent problems such as scorching, deformation, peeling, and dust adhesion. Also, these measures may be effective in making the thickness of the mother more uniform.

If there is no backing in advance, it is preferable to back the father with a metal plate before the mother is separated from the father, since the father is thin. A metal plate of iron, copper, brass, aluminum, stainless steel, bronze, etc. is bonded to the back of the father. Then, the mother is easily separated from the father. The peeled mother has no rough skin. When the father has a surface roughness Ra of 10 nm or less, the mother has a surface roughness Ra of 10 nm or less. Father's surface roughness Ra
Is less than 1 nm, the surface roughness Ra of the mother is also 1 nm.
It is as follows. This is one of the features of the present invention.

The separated father can be used again for manufacturing a mother. One of the features of the present invention is that the father is used repeatedly. In Example 2, the father was used 1000 times. The inventor's guess is that
The father can be used repeatedly 10,000 times or more. This is presumed to be because the mother is made of a resin and does not damage the father at the time of peeling (particularly does not roughen the skin). Since there is no damage, even if used repeatedly 10,000 times or more, the manufactured 10,000 or more mothers have no personality (or very similar personality) to each other. Therefore, their mothers could be compared to clones.

And, compared to expensive fathers, mothers are much cheaper and faster to manufacture. [Third Mold (Sun)] The sun is made of metal like the father. Sun is manufactured in the same manner as Father. In that case, a mother is used instead of the master. Sun is manufactured by plating mother. However, instead of conducting the conductive treatment and plating immediately on the mother, a 1-20 ° photoresist may be applied before the plating. After that, it is made conductive and plated. By doing so, Ra and Wa are somewhat improved. For more details, please see the explanation of the first mold (father). I omit it here.

Since the sun is completed on the mother, it is separated from the mother after completion. After peeling, the mother can be used repeatedly 100 times or more. In order to enhance the flatness of the sun, the back surface of the sun is mechanically polished (1) before the peeling of the sun or (2) after the peeling. (2) When polishing after peeling, to protect the uneven surface of the sun, after peeling from the mother,
A protective coat is applied to the uneven surface of the sun. The protective coat is formed by applying a peelable protective paint and drying.

In any case, the sun peeled from the mother and polished mechanically punches near the center of the sun. The outer diameter of Sun is also punched out. This completes the donut-shaped sun. This allows Sun to ship. As a feature of the present invention, the roughness of the sun after peeling is small.
Therefore, when the mother has a surface roughness Ra of 10 nm or less, the sun has a surface roughness Ra of 10 nm or less. When the surface roughness Ra of the mother is 1 nm or less, the surface roughness Ra of the sun also becomes 1 nm or less. This is one of the features of the present invention. According to the invention, optionally, Ra is 0.5 nm.
Sun having a surface roughness of not more than 0.3 nm (RMS not more than 0.3 nm) can also be produced. Further, if better conditions are selected, a sun having a Ra of 0.3 nm or less (RMS of 0.2 nm or less or 0.1 nm or less) can be provided.

Since the mother is a clone, the sun produced from one father is also a clone. At the extreme, Sun is also a clone of Father. Many expensive suns are made from expensive fathers. If one million resin substrates are required, about 50 suns are required. This is because one sun is damaged in about 20,000 to 30,000 pieces and cannot be used. When preparing 50 suns, the prior art requires 50 ÷ 9 = 6 fathers. This is because a single father can get at most nine suns (brother's suns). In the present invention, 10,000 or more mothers can be obtained from one father. Therefore, even if one sun is manufactured from one mother, 1000 sun is manufactured from one father.
Since zero suns (clone suns) are obtained, one father is sufficient.

When the master II manufactured by RIE is used, the roughness of the sun is small, and a high quality sun is particularly manufactured. [Identification] It is difficult to distinguish such many suns. Therefore, the sun may be stamped at a predetermined position. The position is, for example, if the signal area has a sun radius of 22 mm to 59 mm, the other part (for example, a radius of 20 mm to 21 mm).
mm portion). The inscription may be a simple groove, a recess, or a pit. The inscription may be a number or a symbol. It is preferable that a set of fine concave portions represent characters, numbers, and symbols when viewed with the eyes. The engraving is laser processing,
It is performed by stamping and pressing. Alternatively, the sun may be directly engraved with a blade, a file, a polishing tape, or the like to scratch the sun.

The engraving may be performed on the master, father, and mother. Since these inscriptions are transferred to the resin substrate, it is possible to know which type was used by looking at the resin substrate. The stamp is
Used for quality control of resin substrates. [Molding of Resin Substrate] A resin substrate is manufactured (molded) by a method of transferring irregularities on the surface of a sun using a sun. The molding method includes injection, pressing, casting, and the like. In particular, the injection molding method has high productivity.

The resin used for the resin substrate is generally a thermoplastic resin (particularly a relatively hard resin). Examples thereof include polycarbonate, polystyrene, styrene-based polymer alloy, acrylic resin (for example, polymethyl methacrylate), polyvinyl chloride, polyester, nylon, ethylene-vinyl acetate resin, and amorphous polyolefin. However, a thermosetting resin can be used in some cases. Examples include epoxy resins,
Examples include thermosetting polyurethane, unsaturated acrylic resin, unsaturated polyester, and diethylene glycol bisallyl carbonate resin. The molding of the resin substrate is the same as in the prior art, and will not be described further.

Next, examples will be described. Here, Ra and Wa
The value of was measured by "TOPO-SYSTEM" of Wyko Corp.

[0074]

Embodiment 1 This embodiment will be described with reference to FIG. [Master II] First, two synthetic quartz plates were prepared as substrate materials. These plates have an outer diameter of 185 mm and an inner diameter of 20 mm.
It was processed into a donut-shaped disc having a thickness of 6 mm and a thickness of 6 mm to obtain a substrate (1). Then, the surface of the substrate is each surface roughness:
Precision polishing was performed to Ra = 1 nm or less. After washing, "hexamethyldisilazane as a primer" and a photoresist were sequentially spin-coated on the substrate surface. Upon prebaking, a photoresist layer (2) having a thickness of about 200 nm was formed on each substrate (1). The substrate (1) on which the photoresist (2) is formed is shown in (1) of FIG.

Next, using a laser cutting device,
The photoresist on the first substrate was exposed. The pattern of exposure is pre-pit prepits which become (a) a wobble guide groove pattern and (b) a TOC (table of contents) pattern according to a rewritable MD (mini-disc) format. The track pitch is
1.6 μm, groove width 1.2 μm, groove wobble (wobb
le) The amplitude was about 30 to 40 nm, and the prepit width in the TOC pattern was about 0.4 μm.

Another pattern was exposed on the photoresist on the second substrate. The pattern is 4.7 Gbyte / side
(A) Single spiral land / groove and (b) address pit in accordance with the DVD-RAM format. Track pitch 0.58μm (“land / groove”
Because of the format, the groove pitch is 1.16
μm). The groove width is about 0.58 μm. The pit width of the address part is about 0.3 μm, and the wobble amplitude is about 1
0 to 20 nm.

After exposing the resist on the two substrates,
Each was developed with an inorganic alkali developer. The resist surface was spin-cleaned and then post-baked at 120 ° C. for 30 minutes. As a result, a resist pattern (2) was formed. This situation is shown in FIG. The substrate was placed in a reactive ion etching (RIE) apparatus and dry-etched. This situation is shown in (3) of FIG.

The remaining resist was removed and the substrate was washed to obtain Master II. These masters II have a pattern directly etched on a quartz substrate (1). This situation is shown in (4) of FIG. The first master II (MD format) had a pit and groove depth of about 65 nm. Second
The master II (DVD-RAM format) had a pit and groove depth of about 140 nm.

Since these masters II were manufactured by the RIE process, the side walls of the grooves, the side walls of the pits, and the edges before and after the pits were all very sharp. This brings the following advantages (a) to (f) to the optical disc. (A) The reproduction of the wobble signal is accurate. (B)
CNR is improved. (C) Cross erase and crosstalk are reduced. (E) Dropout of each of the write and read signals is very small. Further, since the surface roughness of the bottom and side walls of the pit and the surface roughness of the bottom and side walls of the groove are very small, noise is reduced.

[Father] The first master disk II was set in a sputtering apparatus, and a surface of about 50 to 70 nm thick Ni
The layer (conductive layer) was deposited. Thus, the conductive treatment was completed. When the master II has deep irregularities, it is preferable to perform sputtering under RF discharge. Under the RF discharge, it is difficult to receive an adverse effect (for example, uneven sputtering speed) due to the charging of the master II. Therefore, in this embodiment, the RF
Sputtering was performed under discharge (power: 400 W). A conductive layer was similarly formed on another master II.

If the Ni layer is thick, the Ni plating layer may come off later. In that case, the thickness of the Ni layer (conductive layer) is reduced to about 10 nm to 40 nm. Next, the master II was placed in a plating bath in which nickel sulfamate was dissolved.
The bath temperature was about 45-55 ° C. Then, by energizing, Ni electroforming was started. At the start, the current density was lowered and gradually increased. The electroforming is performed using the obtained Ni
It stopped when the thickness of the plating layer (3) became 293 μm.

The Ni plating layer (3) was similarly formed on the second master II. This plating (3) mainly constitutes a father. This situation is shown in FIG. The father (3) was peeled off from the master II. The peeled father is shown in FIG. 1 (6). The surface roughness Ra of the father (3) was 1 nm or less. The protective coating was coated on the uneven surface of the father with KLINCOAT S (manufactured by Fine Chemical Japan) by spin coating. After application, the coating was allowed to air dry for about 10 hours. As a result, the uneven surface was covered with the protective coat. After polishing the back of the father, the inside diameter and outside diameter were punched out and dropped. Thus, two donut-shaped fathers were completed. Each father took about 13 hours to finish.

Master II after peeling off the father is not damaged. Then, after each master II was washed, this step was performed again to prepare second fathers. Thus, a total of 2 × 2 = 4 fathers were obtained. A stainless steel substrate was bonded to the back of the father with an epoxy adhesive (not shown). This improves the flatness of the father.

[Mother] An ultraviolet curable resin liquid is prepared. This resin liquid contains 70 parts of acetal glycol diacrylate of Chemical Formula 1, 30 parts of urethane acrylate which is a mixture of Chemical Formulas 2 and 3, and 1-hydroxycyclohexycyclohexyl phenyl ketone (trade name). : Irgacure-184; Ciba-Geigy Co., Ltd.). Chemical structural formula 1

[0085]

Embedded image Chemical structural formula 2

[0086]

Embedded image Chemical structural formula 3

[0087]

Embedded image As a resin liquid, heat and light absorption properties, mold release properties, light resistance,
Considering durability and hardness, the number of colors (APHA) is 30 to 5
0 and a refractive index of about 1.4 to 1.8 at 25 ° C. are preferable. In the present embodiment, in consideration of the releasability and the subsequent electroforming performed a plurality of times, the number of colors is 40, and the refractive index is 1.47 to 1.4.
The resin solution No. 8 was used.

The specific gravity of the resin liquid is 0.8 to 1.3 at 25 ° C.
And a viscosity of about 10 to 4800 CPS at 25 ° C. are preferable from the viewpoint of transferability. In this example, a resin liquid having a specific gravity of about 1.08 and a viscosity of about 4500 to 4780 CPS was used for the purpose of shortening the mother duplication time and reducing the amount of bubbles to be mixed. Viscosity can be achieved by using low molecular weight components. That is, since the molecular weight of urethane acrylate (Chemical Structural Formulas 2 and 3) is as large as about 1,000 to 2,000, the viscosity can be reduced by using another low molecular weight component.

Separately, a blue glass disc having an outer diameter of 200 mm, an inner diameter of 10 mm, and a thickness of 6 mm was prepared. Then, the disc was washed, and a silane coupling agent as a primer was applied to the surface. The silane coupling agent is obtained by dissolving γ-methacryloxypropyltrimethoxysilane (see Chemical formula 4) in a solvent (toluene) to obtain a solution of about 2%. The application method is a spin shower method. After application,
Bake at 120 ° C.

Chemical structural formula 4

[0091]

Embedded image Then, the resin liquid was dropped on the father having the uneven surface facing upward. A glass disk was pressed from above, and the resin solution was sandwiched between the disk and the father. At this time, care was taken to prevent bubbles from entering the resin solution. Further, the glass disk (5) was pressed to uniformly spread the viscous resin liquid over the entire surface of the fuzzer.

The resin liquid is irradiated with ultraviolet rays from a mercury lamp for about 5 to 60 seconds through a glass disk. As a result, the resin liquid was cured to form a hard resin layer (4). Here, the two-layer structure of the resin layer (4) and the glass disk (5) is the mother. This situation is shown in FIG. Next, the mother was peeled from the father. Peeling was performed carefully so as not to damage both. The other three fathers were treated in the same manner to produce mothers. The surface roughness Ra of each mother was 1 nm or less.

The father left after peeling is undamaged and can be used repeatedly. Surprisingly, no resin was attached to the father and no removal of residual resin was necessary. Therefore, the mother was again manufactured using the father as it was. Father repeats 100
Used 0 times. As a result, 2 × 100 from one master II
0 = 2000 mothers (4000 mothers in total) were manufactured. This situation is shown in (8) of FIG.

The production time of the mother is short.
One sheet was produced in 60 minutes. [Sun] Sun was manufactured from each mother. The manufacturing method is the same as that of the above-mentioned father. However, a mother was used instead of Master II. As shown in FIG. 1 (9),
Immediately after manufacture, Sun (6) is on the mother. Therefore,
When the sun is peeled from the mother, a free sun (6) shown in (10) of FIG. 1 is obtained.

After a protective coat was applied to the uneven surface of the sun, the back surface was polished to obtain a uniform thickness. Then, the inner and outer diameters of the sun were punched out and finished. Thus, Ni sun was completed. The thickness of the sun was 293 μm. The surface roughness Ra and undulation Wa of the sun were 1 nm or less. The mother after sun peeling is undamaged and the mother is 100
It could be used more than once. Surprisingly, no resin was attached to the mother, and removal of the residual resin was unnecessary. However, repeated use was stopped here.

Since one sheet of each sun was duplicated from each mother, 2,000 pieces of one kind and 4,000 pieces of two kinds in total were obtained. These fathers and these suns were sequentially set in a “dedicated playback device”, and the playback signals were checked. The types of signals are a tracking signal, a noise, a wobble signal, an address signal, and the number of defects. As a result, the quality of the signal was equal to that of the reproduced signal from the father. Also, the reproduced signals from the 2,000 suns were equivalent to each other.

In the prior art, 2,000 to 223 sheets (= 2000 sheets / 3
÷ 3) Master disk II is required. Master II is very expensive, and in the end, prior art Suns are expensive. On the other hand, in this embodiment, Sun is inexpensive because only one expensive master II is required. About 2,000 suns of each type, each was set in an injection molding machine, and a resin substrate was experimentally molded. The molding could be performed without changing the molding conditions.
For this reason, 2,000 suns of one type have no personality and can be called clones.

[0098]

Embodiment 2 This embodiment will be described with reference to FIG. [Master I] First, two blue glass sheets were prepared as substrate materials. Each of these plates has an outer diameter of 200 mm and an inner diameter of 10 mm.
It was processed into a donut-shaped disc having a thickness of 6 mm and a thickness of 6 mm to obtain a substrate (1). Then, the substrate surface is made to have a surface roughness Ra of 1 n.
m or less. After washing, "hexamethyldisilazane as a primer" and a photoresist were sequentially spin-coated on the substrate surface. When prebaked, the first substrate (1) has a thickness of about 70 nm (MD
About 145 nm for the second substrate (1) (DVD
The photoresist layer (2) was formed. The substrate (1) on which the photoresist (2) has been formed is shown in FIG.
Is shown in

Next, using a laser cutting device,
The photoresist was exposed. The exposure pattern of the first substrate is the same as the MD format of the first embodiment, and the exposure pattern of the second substrate is the DVD-RAM format of the first embodiment.
Same as mat. After exposure, each resist was developed as in Example 1. As a result, a resist pattern (master I) shown in (2) of FIG. 2 was obtained. The thickness of the resist layer is slightly reduced by development, and is about 65 nm on the first substrate.
(For MD), about 140 nm (DVD
For).

In this case, since “residual material having a residual ratio of 95% or more” was used as the photoresist material, the side wall of the groove, the side wall of the pit, and the pit front and rear edges were all sharply formed. Therefore, the reproduction of the wobble signal is accurate. In addition, improvement of CNR, cross-erase
And a reduction in cross-talk. The dropout of the write signal and the read signal is also reduced. Since the surface roughness of the bottom and the side wall of the groove and the surface roughness of the bottom and the side wall of the pit were small, noise was reduced.

[Father] A father was manufactured in the same manner as in [Father] of Example 1 except that the master I was used instead of the master II (see (3) in FIG. 2). After the father (3) was peeled off from the master I (see (4) in FIG. 2), the remaining resist on the surface was washed away with an organic solvent such as acetone. Thereafter, the father was spin-cleaned. Product name: Siritect SILITECTO (ace industry ACE INDUSTR)
IALS Co.) was spin-coated. The backside of the protected father was polished in this manner. In order to adjust the shape of the father, it was cut into a donut shape having an inner diameter of 16 mm and an outer diameter of 170 mm. The thickness of the father was 293 μm.

Since there were two masters I (two types), two fathers were obtained. A stainless steel substrate was bonded to the back of these fathers in the same manner as in Example 1 (not shown). [Mother] In the same manner as in Example 1, a resin mother was manufactured (replicated) from a father. The father after the mother was peeled was not damaged. Surprisingly, no resin was attached to the father and no removal of residual resin was necessary. Therefore, the father was repeatedly used as it was. The repetition was performed 1,000 times, and 1000 mothers were manufactured from one father. This situation is shown in (5) and (6) of FIG. These 1000 mothers should have exactly the same uneven signal.

Similarly, 1000 mothers were duplicated from the second father having another uneven signal. These 1000 mothers should have exactly the same uneven signal. [Sun] Ni sun was manufactured (replicated) from a resin mother in the same manner as in Example 1. The thickness of the Ni sun was 293 μm. The mother after peeling off the Ni sun was not damaged.
Surprisingly, no resin was attached to the mother, and removal of the residual resin was unnecessary. Therefore, the mother was repeatedly used as it was. The repetition was performed ten times, and ten Ni-made suns were manufactured from one mother. This situation is shown in (7) and (8) of FIG. The surface roughness Ra and undulation Wa of the sun were 1 nm or less.

First Mother (MD Format) 100
From 0 sheets, 10 sheets each made of Ni were manufactured. In this way, a total of 10.times.1000 = 10000 suns were obtained. These 10,000 suns have exactly the same uneven signal and have no personality. Therefore, 10,000 suns are likened to clones. Second mother (DVD-R
AM format) has a different signal from the first mother. Ten Ni suns were manufactured from each of the second 1000 mothers. This gives a total of 10 × 1000 = 1
0000 suns were obtained. These 10,000 suns have exactly the same uneven signal and have no personality. Therefore, 10,000 suns are likened to clones.

These fathers and their suns were set in the “dedicated reproducing device” in order, and the reproduced signals were checked. The types of signals are a tracking signal, a noise, a wobble signal, an address signal, and the number of defects. As a result, the quality of the signal was equal to that of the reproduced signal from the father. The reproduced signals from 10,000 suns were equivalent to each other.

Each of 10,000 types of suns was set in an injection molding machine, and a resin substrate was molded in an attempt.
The molding could be performed without changing the molding conditions. for that reason,
10,000 suns of a single species have no personality and are called clones.

[0107]

Example 3 As an injection molding machine, a product name "SD30" manufactured by Sumitomo Heavy Industries, Ltd. was prepared. As resin for the resin substrate, polycarbonate manufactured by Teijin Limited, trade name "AD550"
3 "was prepared and set so that it could be supplied to the molding machine.

Embodiment 2 (DVD @ RAM format)
Out of the 10,000 third molding dies (suns) manufactured in step (1), ten were randomly selected (referred to as first to tenth suns). The first sun was set on the molding machine. Mold temperature 125 ° C, resin temperature 340 ° C, injection pressure 30
At t, the resin substrate was molded under molding conditions with a cycle time of 12 seconds. The thickness of the substrate is 0.6 mm. 60 in 2 hours
0 resin substrates (DVD─RAM format, φ = 1
20 mm).

Thereafter, the first sun is removed from the molding machine,
The second sun was set, and 600 resin substrates were similarly manufactured. At this time, the molding conditions were not changed even when the sun was changed. Similarly, a resin substrate was manufactured using the third to tenth suns. As a result, 600 × 10 = 6000 resin substrates were obtained. Arbitrary two substrates were selected from the resin substrates molded from each sun. That is, a total of 2 × 10 = 20 resin substrates were selected. The groove shape and the pit shape of these 20 resin substrates were observed with an electron microscope (HR-SEM) and an atomic force microscope (AFM).

Here, the shape means the width of the top, the width of the bottom,
It refers to four types of depth and inclination of the side wall. As a result, it was found that any of the 20 resin substrates had the same groove shape and pit shape. Further, sludge (or warp) and birefringence of these resin substrates were measured. As a result, the warpage was within ± 0.3 degrees for all substrates. Birefringence is 50 for any substrate
within nm. Further, when the surface undulation Wa was measured, it was 1 nm or less. Furthermore, none of the substrates had a "cloudy cloud".

[0111]

Comparative Example 1 Ten masters I (D
VD-RAM format). At this time, the manufacturing conditions were not changed at all. Then, 10 fathers were manufactured from each master I in the same manner as in Example 2. At this time, the manufacturing conditions were not changed at all.

The obtained 10 fathers were punched into the same outer diameter and the same inner diameter as the sun of Example 2, respectively. These ten fathers have individuality based on experience. Example 3 using ten punched fathers instead of sun
Was repeated. At this time, 600 resin substrates were molded without changing the molding conditions even if the father was changed. From the obtained substrates, 600 were arbitrarily selected, and their tilt and birefringence were measured. As a result, the warp is ± 0.3 degrees (degre
e) A non-defective substrate within the range of 40
%Met. A non-defective substrate having a birefringence within 50 nm was regarded as a non-defective product, and the non-defective ratio was 50%. A good substrate is the best product for both warpage and birefringence, and the best product rate is 20
%Met.

Therefore, a resin substrate was molded under various molding conditions. By repeating the above trial and error, we found the conditions for the best product rate to be 100%. It took six hours to find. In addition, 5% of the substrates had "cloudiness". Substrates with "cloudiness" were discarded as defective.

Two best products (without "cloudiness") were arbitrarily selected from the best molded products from each father (10). Electron microscope (HR-SEM) for the selected substrate
The groove shape and the pit shape were observed with an atomic force microscope (AFM). As a result, none of the twenty resin substrates had the same groove shape and the same pit shape. Moreover, because the molding conditions are different,
There were not a few substrates with rounded corners of the lands and substrates with small protrusions (corners) at the ends of the lands.

[0115]

According to the present invention, sun (third molding die) can be mass-produced inexpensively from one master. And those suns are less rough. The surface roughness of the sun is (almost) the same as the master. In the prior art, the surface roughness of the sun is inferior to the master. Therefore, if the sun of the present invention is used, a resin substrate evaluated at a high level (for example,
Optical disc) can be manufactured. The evaluation items include noise, modulation degree, jitter, error rate, cross-talk, clock stability, and fine clock mark quality of the wobble format signal.

Accordingly, the Sun of the present invention describes an optical disk having a wobble signal, for example, CD @ R, CD-RW, M
D, DVD-ROM, DVD-R, DVD-RAM, D
VD-RW, etc. "
The plurality of suns manufactured according to the method of the present invention have no personality so much as to be called clones. Therefore, when the resin substrate is molded by setting the sun in the injection molding machine, it is not necessary to change the molding conditions for each sun. Molding conditions include mold temperature, resin temperature, injection pressure, cycle time, and the like. In the prior art, a resin substrate having the same transfer shape, warpage, birefringence, and the like cannot be obtained unless the molding conditions are changed. However, it is quite troublesome to change the molding conditions, and molding companies dislike it. In contrast, when using the sun (s) of the present invention, there is no trouble.

Even if the molding conditions for injection molding are finely adjusted,
A pattern called "cloudy" by those skilled in the art may appear on the molded resin substrate. The portion of the pattern does not have a reflection like a mirror surface, and the appearance is impaired. In addition, in the case of a resin substrate that requires high precision, cloudiness means a defective product. The sun of the present invention does not cause fogging. In the prior art, foreign matters often adhere to the sun after the sun is peeled off the Ni mother. This foreign material does not seem to fall off easily by washing. According to the inventor's guess, the cause of the foreign matter is the passivation applied to the Ni mother to facilitate the peeling of the sun. Potassium dichromate and potassium permanganate used for passivation remain on the Ni mother surface. These materials appear to react with and adhere to the sun. This will also occur when replicating a Ni mother from a Ni father. Although it is not known exactly for this reason, prior art mothers and suns have rough skin.

In the present invention, since no passivation is required, foreign matter does not adhere to the mother or the sun. It is easy to clean the father, mother and sun. In this specification, the case where the resin substrate is used for an optical disk has been described in detail, but the resin substrate may be used for other purposes. Any resin substrate having fine irregularities can be formed using the sun of the present invention. Examples of such a resin substrate include a substrate for a magnetic disk (hard disk), a substrate for an optical card, a substrate for a liquid crystal device, a substrate for a semiconductor device,
Substrates for printer components, components for information recording / reproducing devices, components for personal computers, components for automobiles, optical components themselves (for example, zone plates,
Aspherical lenses, diffraction gratings, hologram plates, photomasks, reticles) or their substrates, substrates for encoder components, and the like.

[Brief description of the drawings]

FIG. 1 is a process chart according to Example 1 (master II) of the present invention.

FIG. 2 is a process chart according to Example 2 (master I) of the present invention.

FIG. 3 is a process chart comparing Example 2 (master I) of the present invention with the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate (glass, quartz) 2 ... Photoresist 3 ... Father (1st molding type) 4 ... Resin 4b ... Ni mother (2nd molding type) 5 ... Substrate ( 6) Sun (third mold) Fig. 1 (4) ... master II Fig. 2 (2) ... master I Fig. 1 (8) ... resin mother (second) (Molding die) FIG. 2 (6): Resin mother (second molding die) FIG. 3 (6A): Resin mother (second molding die)

Claims (21)

[Claims] 1. A step of preparing a first mold made of metal,
A step of molding a second mold made of resin from the first mold and a step of molding a third mold made of metal from the second mold. Production method. 2. The method according to claim 1, wherein the first mold is “manufactured by an electroforming method using a predetermined resist pattern”. 3. The method according to claim 1, wherein the first molding die is “manufactured by an electroforming method using a ceramic mold having a predetermined concavo-convex pattern”. 4. The ceramic mold according to claim 3, wherein said ceramics mold is formed by etching a ceramic substrate on which a predetermined resist pattern is formed and then removing the remaining resist. the method of. 5. The method according to claim 3, wherein the ceramic is quartz. 6. The method according to claim 1, wherein the second step is repeated by repeatedly using the first mold, thereby forming a plurality of second molds. 7. The method according to claim 1, wherein the second step is repeated by repeatedly using the same first mold, thereby forming 20 or more second molds. 8. The surface roughness Ra of the first mold is 10n.
2. The method according to claim 1, wherein the surface roughness Ra of the second mold is 10 nm or less. 9. The surface roughness Ra of the second mold is 10n.
2. The method according to claim 1, wherein the surface roughness Ra of the third mold is 10 nm or less. 10. The first mold having a surface roughness Ra of 1 nm.
The method according to claim 1, wherein the surface roughness Ra of the second mold is 1 nm or less. 11. The surface roughness Ra of the second mold is 1 nm.
The method according to claim 1, wherein the surface roughness Ra of the third mold is 1 nm or less. 12. The method according to claim 1, wherein the resin forming the second mold is a thermosetting resin. 13. The method according to claim 12, wherein the thermosetting resin is a radiation-curable resin, and the second mold is made of a resin cured by irradiation with radiation. 14. The method according to claim 1, wherein the resin forming the second mold is a resin that does not adhere to the first mold and / or the third mold. . 15. The mold according to claim 1, wherein the mold is a mold for molding a resin substrate for an information recording medium.
14. The method according to 14. 16. A method for producing a resin substrate for an information recording medium from a raw material resin by an injection molding method using a molding die produced by the method according to claim 1. 17. A step of preparing a first mold made of metal,
Forming a second resin mold from the first mold. A method of manufacturing a resin mold. 18. A metal third metal having a surface roughness Ra of 1 nm or less.
Mold. 19. A third metal mold having a surface roughness Ra of 0.5 nm or less. 20. A metal third mold having an effective diameter of 50 to 130 mm, wherein the surface waviness Wa is 1 nm or less. 21. A molded resin substrate having an effective diameter of 50 to 130 mm and a surface waviness Wa of 1 nm or less.