JPH01251448A - Optical disk molding die - Google Patents

Abstract

PURPOSE:To manufacture a plastic duplicate disk with high accuracy by covering a photoresist layer on a metallic substrate, forming irregularity corresponding to recording information by photoirradiation, and forming a protection layer additionally. CONSTITUTION:A positive type photoresist layer 2 is covered on the metallic substrate 1, and light-chemical reaction is generated by projecting light corresponding to a signal, and the irregularity corresponding to information to be recorded on the layer 2 is formed by a solvent processing. At this time, at the positive photoresist layer, the photolysis of an exposure part is performed, then, it becomes a part possible to be dissolved in a solvent, and by applying the solvent processing, a recessed part 3 is formed at the part and a projecting part 4 at the part other than that. Furthermore, the projection layer 5 consisting of at least one kind of metallic thin films selected from an Ni, a Cr, a Co, a Ti, or an Fe, by a sputtering method or a vacuum vapor-depositing method is covered. It is set as a molding die as it is, and a duplicate disk 6 is manufactured by applying press molding or injection molding on plastic.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is for manufacturing a large number of plastic multi-v blocks by transferring minute irregularities corresponding to analog signals such as video signals or digital signals. This invention relates to an optical disc mold.

(Prior Art) A conventional method of manufacturing a plastic replica mold for an optical disk will be described with reference to FIGS. 3(a) to 3(f).

First, a photoresist layer 72 is coated on the glass substrate 11 (FIG. 3(a)), and light corresponding to a signal is irradiated to form a photoresist layer 72.
The unevenness 1 corresponding to the information to be recorded on the photoresist layer 12 is created by causing a chemical reaction (FIG. 2(b)) and by solvent treatment.
3.14 is formed ((C) in the same figure).

The material that has gone through the steps up to FIG. 3(C) in this way is used as a raw material. Next, a metal plating layer 15 is placed on this master.
After forming the same section (d)), the thin metal plating plate 16 is peeled off (FIG. (e)).

Either use this metal plating thin plate 16 as it is as a molding die, or
Alternatively, a stamper is produced from this metal plated thin plate 16 through two plating and peeling processes, and a plastic is press-molded or injection-molded using this as a molding die, thereby producing a reproduction plate 17 (FIG. (f)). Manufacture.

In addition, there are various methods known for producing a one-size prototype in addition to the ones mentioned above, but in order to obtain a molding mold, it is best to go through several plating and pinning processes as described above. It is numerical.

However, this plating and peeling process is a complex and delicate process that requires skill. ! ! Returning the information not only increases the number of steps, but also poses problems in terms of the accuracy of recorded information and costs. Furthermore, when a metal plated thin plate is used as a molding die, there is a problem in that distortion tends to occur during molding, and the thickness of the plastic reproduction plate tends to be uneven.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems, and provides an optical disc molding die that can be manufactured at low cost and that can manufacture highly accurate plastic duplication discs. The purpose is to

[Configuration of the Invention (Means and Effects for Solving the Problems) The optical disc mold of the present invention includes a metal substrate, and a photoresist coated on the metal substrate, on which unevenness corresponding to information to be recorded is formed. and a protective layer made of at least one metal thin film selected from Ni, Cr, Co, T1, and Fe, which is coated on the metal substrate and the photoresist layer.

The optical disk molding mold of the present invention covers a metal substrate with a photoresist layer, irradiates it with light to form unevenness corresponding to the information to be recorded by a photo-chemical reaction, and then coats the metal substrate with Ni, Cr, etc. by sputtering or vapor deposition. , Co, Ti, and Fe by forming a thin metal film (protective layer) of at least one of them.

Then, as in the past, a plastic duplication disc can be manufactured by press molding or injection molding plastic using this optical disc mold. At this time, since an oxide film is usually formed on the surface of the metal thin film constituting the protective layer, the mold releasability of the plastic is extremely good.

The optical disc molding mold of the present invention is different from conventional molds,
Since it is manufactured without repeating the plating and peeling processes, the process is simple, the accuracy of recorded information does not deteriorate, and the cost is therefore low. In addition, by using a metal substrate with a thickness that does not cause distortion during molding, non-uniformity in the thickness of the plastic duplicator can be suppressed. Another advantage is that the depth of the unevenness corresponding to information can be precisely regulated by the thickness of the photoresist layer. However, when forming the photoresist layer, concentration, temperature,
It is necessary to sufficiently control solvent treatment, exposure conditions, etc., and control the thickness of the photoresist so that a depth of unevenness suitable for optical recording is obtained.

In addition, in order to prevent distortion of the metal substrate due to temperature, pressure, etc. during molding, it is desirable that the thickness of the metal substrate is 1M or more.Also, there is no particular limit to the thickness of the gA protective layer, but the thickness If it is too thick, the protective layer will easily peel off, and the size of the unevenness will be smaller than the original one formed on the photoresist layer by the amount formed on the sidewall of the step part.
- It is desirable that the number of people is 10001-1-/ or less.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In addition, FIGS. 1(a) to (e) and FIGS. 2(a) to (e) are cross-sectional views showing the manufacturing process of the optical disc mold and the plastic duplication disk according to the present invention. Diagram (a)
2(a) to 2(e) are cases in which a positive photoresist is used, and FIGS. 2(a) to 2(e) are cases in which a negative photoresist is used.

Example 1 First, a positive photoresist layer 2 is coated on a metal substrate 1 made of a metal that can withstand the temperature, pressure, etc. during plastic molding, such as soft #4, and has a thickness of 5 cm (Fig. 1<a)). , irradiate light corresponding to the signal to cause a photo-chemical reaction (see figure (b)
)) - Forming irregularities corresponding to information to be recorded on the positive photoresist layer 2 by solvent treatment. At this time, in the case of a positive photoresist, the exposed portion is photodecomposed and becomes soluble in a solvent, and when treated with a solvent, a concave portion 3 is formed in that portion and a convex portion 4 is formed in the other portion ((c) of the same figure). , and then coated with N1.5 by sputtering or vacuum evaporation ((d) in the same figure). Using this directly as a molding die, press molding or injection molding of plastic was performed to form a replica plate 6 ((e) in the same figure). )) is also manufactured.

Example 2 First, a negative photoresist layer 7 is coated on a metal substrate 1 having a thickness of 5 ratn, for example, with a mild steel layer (FIG. 2(a)).
Then, light corresponding to the signal is irradiated to cause a photo-chemical reaction (FIG. 3(b)), and by solvent treatment, unevenness corresponding to the information to be recorded is formed on the negative photoresist layer 7. At this time, in the case of the negative photoresist, the exposed portion becomes insoluble in the solvent, and when treated with the solvent, a convex portion 4 is formed in that portion and a concave portion 3 is formed in the other portion (FIG. 4(C)). Furthermore, NL, Cr, C01 by sputtering method or vacuum evaporation method
A protective layer 5 made of at least one metal thin film selected from Ti and Fe and having a thickness of about 30'# is coated (as shown in the figure).
d)). Using this mold as it is, press molding or injection molding of plastic is performed to manufacture the duplication disk 6 (FIG. 6(e)).

As shown in Example 1.2 above, the optical disc molding die according to the present invention is manufactured without repeating the plating and peeling processes, so one step is simple, and the accuracy of recorded information does not deteriorate. Moreover, it is low cost. Also, the thickness is 5 r
By using the am metal substrate 1, it is possible to prevent distortion during molding, and it is possible to manufacture a high-quality plastic reproduction board 6 with a more uniform wall thickness than when using a conventional molding die. Na.

In Example 1.2, the photoresist layer was directly coated on the metal substrate, but CrO2 or the like may be formed as an antireflection layer on the metal substrate.

Further, even if a dye is added to the photoresist layer in order to prevent reflection from the metal substrate, the effects of the present invention will not be affected in any way.

[Effects of the Invention] As described in detail above, the optical disc molding die of the present invention can be manufactured at low cost and can produce a highly accurate plastic composite aX, and has great industrial value.

[Brief explanation of the drawing]

FIGS. 1(a) to (e) are cross-sectional views showing the manufacturing process of an optical disc molding die and a plastic duplicating disk when a positive photoresist is used in Example 1 of the present invention, and FIGS. 2(a) to 2(e) are (e) is a cross-sectional view showing the manufacturing process of an optical disc mold and a plastic duplication disk when negative photoresist is used in Example 2 of the present invention, and FIG. 3 (a)
-(f) are cross-sectional views showing the manufacturing process of a conventional optical disc mold and a plastic duplicating disc. 1... Metal substrate, 2... Positive photoresist layer,
3... Concave portion, 4... Convex portion, 5... gA protective layer, 6.
...Plastic reproduction disc, 7...Negative photoresist layer. Appearing agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] a metal substrate, a photoresist layer coated on the metal substrate and having irregularities corresponding to information to be recorded, and Ni and C coated on the metal substrate and the photoresist layer.
1. An optical disk molding die comprising a protective layer made of at least one metal thin film selected from R, Co, Ti, and Fe.