JPH0419314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a method for manufacturing an electroforming mold used as a synthetic resin molding mold or the like.

(Prior Art) Conventionally, electroforming molds have been used as synthetic resin molding molds that require reproduction of precise patterns. For example, based on a single master on which a fine and precise uneven pattern such as a rainbow pattern is formed, a large number of electroforming molds (stamper molds) having patterns whose unevenness is opposite to the uneven pattern of the master are created. There are known means to obtain .

That is, after forming a conductive film on the patterned surface of the master (depending on the material of the master, the conductive film may be formed via an insulating peeling layer (hereinafter simply referred to as a peeling layer)). After performing casting and removing the plating layer integrally formed on the conductive film by electroforming from the master mold to obtain a master mold having an uneven pattern opposite to that of the master mold, the master mold is A plurality of molds having a pattern having an uneven pattern opposite to that of the master mold (that is, a pattern that matches the uneven state of the master) are placed on the patterned surface of the mold via a release layer in the same manner as in the formation of the master mold. Further, from each mother mold, a plurality of stampers having a pattern whose uneven state is opposite to that of the mother mold (that is, a pattern that matches the uneven state of the master mold) are obtained from each mother mold by the same method. Get the mold.

In this case, in the relationship between the master mold and the master mold, the master mold is the mother mold and the master mold is the child mold. Similarly, in the relationship between the master mold and the mother mold, the former is the mother mold and the latter is the child mold, and the same holds true for the relationship between the mother mold and the stamper mold.

(Problems to be Solved by the Invention) In the electroforming mold manufacturing method described above, the release layer is a chromate film formed on the surface of the matrix by immersing the matrix in sodium chromate, sodium sulfide solution, etc. or sulfide film.

However, such chemically formed films are easily contaminated with impurities, and there are problems with the insulation between the matrix and the conductive film formed thereon. In addition, the thickness of the film is unstable and requires skill to control.Furthermore, the film is extremely fragile, so care must be taken when washing with water after the film is formed, and during electroforming. There was a problem that the workability was poor due to peeling.

The present invention has been made in view of such problems, and an object of the present invention is to provide a means for forming a release layer that can easily form a release layer on a matrix, has excellent insulation properties, and is free from problems in terms of strength. With the goal.

(Means for Solving the Problems) The method for manufacturing an electroforming mold of the present invention designed to achieve the above object is characterized by forming a pattern on the matrix by ion plating as a release layer. An oxidized Al layer is formed on the surface via an Al layer,
and the total thickness is 0.2 μm or less (Example) The present invention will be described in detail below with reference to an example in which a large number of stamper molds are manufactured from a single master plate on which a fine uneven pattern is formed. .

The master used in this example is a plastic film, a glass plate, or a glass plate coated with a concave-convex pattern in which protrusions with a depth of about 0.1 μm are formed at intervals of several μm, such as a rainbow pattern. A non-conductive master, such as a holographic master, is used, which is made by irradiating a photoresist film with a precise line drawing using a laser beam and removing the unexposed areas to create a fine uneven pattern. It goes without saying that the pattern on the master disc may be formed by superimposing a suitable pattern on such a fine pattern by screen printing or the like.

First, as shown in FIG. 1, a conductive film 2 is placed on a master 1.
form. The conductive film 2 is necessary to integrally form the plating layer in the next step of electroforming, and is usually
It is formed using Ni or Cu by vacuum evaporation, sputtering, ion plating evaporation, etc. A material formed by ion plating is preferable because it does not peel off during electroforming. The thickness of the conductive film 2 is usually 0.04 to 1 μm.

After forming the conductive film 2, it is immediately attached to an electrolytic plating jig and electroforming is started to form the plating layer 3 integrally with the conductive film 2 as shown in FIG. For electroforming, nickel plating or copper plating is applied depending on the material of the conductive film 2. The thickness of the plating layer 3 is such that it can sufficiently reinforce the conductive film 2 and can be handled mechanically, and a thickness of about 200 μm is sufficient. Of course, it may be made thicker than this. In addition, in order to obtain this level of plating thickness, in the case of nickel plating, 0.5
It takes 35-3.5 hours at a current density of ~5 A/ _dm2 , and 24-4.5 hours at a current density of 1-5 A/ _dm2 for copper plating.

After electroforming is completed, the master 1 on which the conductive film 2 and the plating layer 3 are formed is removed from the jig, and after washing and drying, the electroformed plate on which the conductive film 2 and the plating layer 3 are integrally formed is mechanically replaced with the master 1. The master mold 4 is obtained by further peeling.

When the thickness of the master mold 4 is about 200 μm, a glass plate with a thickness of about several mm may be bonded to the back surface of the master mold 4 for reinforcement.

Further, when a holographic master is used as the master, the resist film adheres to the master mold during peeling, so it is necessary to dissolve and remove the resist film with an organic solvent such as alcohol. Further, when a glass master is used, it is preferable to first provide a release layer, which will be described later, on the patterned surface of the master, and then form a conductive film. The release layer serves as a protective layer for the master.

Next, as shown in Fig. 3, Al is applied onto the pattern surface of the master mold 4 by ion plating.
After forming a peeling layer 5 with a two-layer structure in which an oxidized Al layer is formed between layers, and forming a conductive film 6 thereon, a plating layer 7 is integrally formed on the conductive film 6 by electroforming. . The electroformed plate composed of the conductive film 6 and the plating layer 7 is peeled off from the interface on the conductive film 6 side of the peeling layer 5 formed on the master mold 4 to become the mother mold 8. The conductive film 6 and the plating layer 7 are formed by the same means as when the master mold 4 is manufactured.

The thinner the release layer 5 is, the better in order to accurately copy the fine pattern of the master mold 4 onto the mother mold 8, but insulation and strength must be ensured. If the insulation is impaired due to the occurrence of pinholes or the incorporation of impurities, the master mold 4 and the mother mold 8 will be partially fused together, making it difficult to separate them and damaging the pattern surface of the master mold 4. That means doing so. Also, if the strength is insufficient, it will be difficult to handle.
Peeling begins to occur during the long electroforming process.

In the present invention, the peeling layer 5 is formed by ion plating not only the Al layer but also the Al oxide layer, so that a dense Al oxide thin film of about 0.04 μm and excellent strength can be easily formed. This thin film has excellent insulation properties due to its high purity.
Note that the upper limit of the total thickness of the two release layers is 0.2 μm in order to ensure reproducibility of fine patterns.

The peeling layer 5 is formed by aluminum ion plating, then introducing oxygen gas and oxidizing the surface layer of the aluminum layer by oxygen discharge, resulting in a two-layer structure in which Al oxide is polymerized and integrated on the remaining Al layer. formed into something.

When performing an oxidation treatment after forming an aluminum layer, it is helpful to protect the pattern surface if the aluminum layer is left in contact with the pattern surface without oxidizing the entire aluminum layer. That is, when the mother mold 8 is peeled off from the master mold 4, the peeling layer partially adheres to the mother mold 8 side and the master mold 4
The pattern surface may be damaged, but if the pattern surface is covered with an aluminum layer, the damage will not extend to the pattern surface. Considering that a large number of mother molds 8 are manufactured from the master mold 4, it is important that the pattern of the master mold 4 is not damaged. This two-layered release layer is made by introducing oxygen gas during aluminum ion plating to form aluminum oxide during aluminum evaporation.
It can also be obtained by integrally forming an Al oxide layer on top of the layer.

In addition, when manufacturing a large number of mother molds 8 from the master mold 4, it is better to completely remove the release layer 5 formed on the pattern surface of the master mold 4 each time and form a new release layer again. Electroforming can be performed faithfully to the master mold 4. This is because, as described above, when the mother mold 8 is peeled off from the master mold 4, the peeling layer 5 formed on the master mold 4 may be damaged.

After forming a release layer 9 on the patterned surface of the mother mold 8 obtained as above, as shown in FIG.
A conductive film 10 is formed and electroformed to obtain a plating layer 11 integrally formed on the conductive film 10. Then, as shown in FIG. 5, the conductive film 10 and plating layer 11 are peeled off from the mother mold 8, and the master mold 4
A stamper mold 12 having a similar uneven pattern is obtained. In this case, the peeling layer 9, the conductive film 10, and the plating layer 11 are formed as described above. Furthermore, the method for obtaining a large number of stamper molds 12 is the same as the method for obtaining a large number of mother molds 8.

The stamper mold 12 is flat-polished on the side opposite to the pattern to eliminate variations in thickness during plating, cut to an appropriate size, and mounted on a resin mold.

In this way, from one master 1 to the master mold 4,
A number of stamper molds 12 can be manufactured by creating a mother mold 8 and repeatedly electroforming each mold as many times as desired.

Next, a specific example will be described in which a large number of Stirban molds are obtained using a PET (polyethylene terephthalate) film on which a rainbow pattern is formed as a master.

(1) Convex portion with a height of 0.1 μm (pitch of the convex portion: 1 to 1.8 μm)
Thickness with rainbow pattern formed by
A 50 μm PET film was cut into 150×150 mm pieces and washed with an organic solvent. Then, by screen printing, marks are placed on the patterned surface of the PET film.
Letters, figures, etc. were printed and dried.

(2) Next, a conductive film of nickel or copper was formed on the patterned surface of the PET film by high frequency excited ion plating.

・Ion plating conditions Ultimate vacuum 5×10 ^-5 Torr Argon pressure 3×10 ^-4 Torr High frequency power 100W Film thickness 0.04μm 0.06μm, 0.1μm Evaporation method Nickel Electron beam evaporation Copper, resistance heating method (3) Conductive film Immediately after forming, it was attached to an electrolytic jig and electroforming was started by nickel plating or copper plating.

(4) When the thickness of the plating layer reaches 200 μm, electroforming is finished, removed from the jig, washed with water, and dried.
Only the electroformed plate was peeled off from the PET film using tweezers to obtain a master mold.

(5) After adhering and reinforcing a 2 mm thick glass plate to the back side of the master mold using epoxy adhesive, a 0.1 μm aluminum layer is formed on the patterned surface of the master mold by ion plating, followed by ion plating. Oxygen gas was introduced into the teating device and the aluminum surface was oxidized by oxygen discharge to form a peeling layer with a two-layer structure consisting of an Al layer and an oxidized Al layer. Ion plating conditions etc. are as follows.

・Aluminum ion plating conditions Ultimate vacuum level 5×10 ^-5 Torr Argon pressure during bombardment 5×10 ^-4 Torr Argon pressure during vapor deposition 3×10 ^-4 Torr High frequency power 100W Bombardment time 10 minutes Evaporation method Resistance heating method/Oxidation treatment Conditions: Oxygen pressure: 5×10 ⁻⁴ Torr High frequency power: 100 W Oxidation time: 20 minutes (6) After forming the release layer, a conductive film was deposited thereon by ion plating. Ion plating conditions are the same as (2).

(7) Immediately after forming the conductive film, it was attached to a plating jig and electroforming was performed until the plating layer was 200 μm thick.

(8) After electroforming, it was removed from the jig, washed with water, dried, and then the plating layer (electroformed plate) integrally formed on the conductive film was peeled off from the master mold using tweezers. At this time, the release layer remained completely on the master mold side, and only the electroformed plate was peeled off, yielding a mother mold.

(9) Using the mother mold as a mother mold, the steps (5) to (8) above were performed in the same manner to obtain a stamper mold.

(10) When obtaining a stamper mold from the same mother mold again, each time the release layer remaining on the mother mold is dissolved and removed with a 20% aqueous sodium hydroxide solution to form a new release layer (6) ~ (8) steps were performed. As described above, a large number of stamper molds were obtained from a PET film master disk on which a single rainbow pattern was formed, but because the release layer was of extremely high quality, the pattern of the matrix was not damaged, and all stamper molds were The stamper mold formed an extremely clear uneven pattern.

(Effects of the Invention) As explained above, according to the present invention, the release layer formed on the patterned surface of the matrix is formed by ion plating, so that a dense layer can be formed on the patterned surface via the Al layer. A peeling layer with a two-layer structure consisting of a high-purity Al oxide layer with excellent strength can be easily formed, and there will be no peeling or insulation failure during the subsequent electroforming process, making it easy to handle.

In addition, since the total thickness of the release layer is 0.2 μm or less, even if the pattern of the matrix is formed by minute irregularities such as a rainbow pattern, the reproducibility will not be impaired. .

Furthermore, since the patterned surface of the matrix is covered with the Al layer of the release layer, when the child mold is separated from the matrix by the oxidized Al layer after electroforming, even if the matrix pattern is a fine pattern, There is no risk of damaging the pattern surface, and the reproducibility of fine patterns is extremely excellent even when the matrix is reused.

The method for manufacturing an electroforming mold of the present invention can easily form a release layer with excellent strength, insulation properties, and fine pattern reproducibility, and has great industrial utility value.

[Brief explanation of drawings]

Figures 1 to 5 are explanatory diagrams of the manufacturing process of the example. Figure 1 is a cross-sectional diagram showing a state in which a conductive film is formed on a master, and Figure 2 is a diagram showing a state in which a master mold is formed. FIG. 3 is an explanatory cross-sectional view showing the state of formation of the mother mold, FIG. 4 is an explanatory cross-sectional view showing the state of formation of the stamper mold, and FIG. 5 is a cross-sectional view of the stamper mold. 1...Master disc, 2,6,10...Conductive film, 3,7,1
DESCRIPTION OF SYMBOLS 1... Plating layer, 4... Master mold, 5, 9... Peeling layer, 8... Mother mold, 12... Stamper mold.

Claims (1)

[Claims] 1. After forming an insulating release layer on the patterned surface of the master mold on which a fine uneven pattern is formed, and forming a conductive film on the release layer, a plating layer is formed on the conductive film by electroforming. In the method for producing an electroforming mold, the plating layer integrated with the conductive film is removed from the mother mold to obtain a child mold having a pattern with an uneven pattern opposite to that of the mother mold, wherein the peeling layer is 1. A method for producing an electroforming mold, characterized in that an oxidized Al layer is formed on the patterned surface of a matrix via an Al layer by ion plating, and the total thickness is 0.2 μm or less.