JPH01220154A - Manufacture of guide groove of optical card - Google Patents

Abstract

PURPOSE:To easily form guide grooves each in parallel line shape by using the photo-mask of an optical recording part to include the guide groove, executing a copy on a substrate, preparing resist master disk and executing compressing and moulding with a stamper which is made from this master disk. CONSTITUTION:A resist film 6 is laminated on the surface of a glass substrate 5 and exposure and development is executed with using a chrome mask 4 to plot a guide groove 1 and a pattern 3 by electronic line plotting, etc. Then, a resist master disk 7 is obtained. Next, metal is evaporated to the disk 7, a conductive film is formed and the stamper is prepared by a nickel electric casing method. Thus, the guide groove 2 of an optical card can be easily prepared with using thermal press.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a guide groove for an optically writable optical card;
The present invention relates to a method of manufacturing a so-called pre-group.

<Prior Art> In place of the magnetic cards conventionally used in cash cards, credit cards, etc., optical cards having a huge storage capacity are currently being proposed. As a method for optically recording information used in this optical card, a wide variety of recording principles and recording materials have already been proposed as direct read-after-write (DRAM). That is, rather than using emitted light from a light source such as a laser as an excitation light source in the photon mode of silver salts, diazonium salts, etc., which have been known for a long time, it is possible to excite transitions, expansion, melting, and decomposition due to the temperature dependence of material properties. This is so-called heat mode recording, which is used as a heat source to cause physical and chemical changes such as. Therefore, in this heat mode recording, even if the photosensitive material is exposed to synchrotron radiation before or after the desired recording is performed, as long as the temperature is not raised to a temperature that causes a physical property change that causes permanent deformation of the photosensitive material. It has the characteristic of not being affected by

This has the advantage that it is not necessary to handle the recording medium in a limited environment such as a dark room. Another feature of the conventionally proposed systems is that the recording green area, ie, the bit area, is achieved by removing the sensitive material.

This means that the recording formation on the medium side is also digitally expressed as an analogy to the digital signal in the input/output device of the recording medium-1.

By the way, in order to record and reproduce information with high reliability, it is necessary to scan the recording film with a laser beam with good brightness and accuracy. Therefore, it is necessary to form a guide groove, which is a target to be followed by a laser beam, precisely and stably within the surface of the recording film. For DRAW format optical discs, the guide groove is usually a glass disk coated with photoresist with a diameter of 1 mm.
Using laser light in the sensitive wavelength range of the photoresist focused around μm, the laser spot is sent at a constant speed from the inner circumference to the outer circumference (or from the outer circumference to the inner circumference) to form a continuous spiral track-shaped exposure trace, and then A resist pattern is formed by development, and a stamper having this shape is made by applying a technique such as Ni plating, and this stamper is used as a mold to form a guide groove on a plastic disk. Plastic molding methods include injection molding, injection compression molding, compression molding,
There are extrusion molding, continuous cast molding, cell cast molding, etc., but injection molding is mainly used, and the guide groove of the optical card is also manufactured by the above-mentioned method.

<Problems to be Solved by the Invention> However, at present, guide grooves in optical cards are mainly in the form of parallel lines rather than in the form of spiral tracks in optical disks. With this shape, for example, when forming an exposure trace of a guide groove using a laser beam, the substrate must be moved two-dimensionally with respect to the laser beam, so the
In order to accurately form exposure traces of parallel lines with an interval of m, the operation becomes quite difficult and the apparatus becomes complicated. Furthermore, even if a good exposure trace of the guide groove is formed here, the next developing method can be applied to a spiral track-shaped guide groove, but it cannot be applied to a parallel line-shaped guide groove as it is. For this purpose, the equipment must also be improved. Furthermore, since optical cards are currently thinner than optical disks, at about 0.8 μm, it is difficult to manufacture them by injection molding.

<Means for Solving the Problems> The present invention has been made to solve the above problems.
In a method of manufacturing a guide groove for an optical card, which is provided for accurately positioning a recording spot in an optical recording part of an optical card, a resist is applied on a highly smooth substrate, and a predetermined pattern of an optical recording part including the guide groove is manufactured. A resist pattern is formed on the substrate by exposure using a mask having a mask, and then developed to form a resist pattern replicating the predetermined pattern on the substrate to produce a resist master, and compression molding is performed using a stamper made from the resist master, This is a method of manufacturing a guide groove for an optical card, the method comprising forming a guide groove.

<Example> The present invention will be explained in detail using examples.

The details of the method for manufacturing a guide groove of an optical card according to the present invention are as follows.

i) Fabrication of a mask As a method for fabricating a mask having a pattern in which guide grooves are present at regular intervals within the optical recording area of an optical card, there are methods that apply etching technology, methods that apply cutting technology, etc. However, if the pattern is on the order of several μm, a method using etching technology is particularly desirable. An example of a method that applies etching technology is to create a thin film of corroded metal, alloy, etc. on a smooth substrate (mainly a glass substrate) by vacuum evaporation, sputtering, etc., and then apply photoresist on the thin film. Apply. Types of resist include regular ultraviolet irradiation type resist, deep uV (far ultraviolet rays)
There are resists, electron beam resists, X-ray resists, etc., and the light source used and the resist that can precisely and accurately reproduce the pattern of the guide grooves are selected and used. Then, the guide groove pattern and preformat pattern are formed as exposure traces on the resist, and after development, the exposed thin film of metal, alloy, etc. is etched, and the guide groove pattern is drawn in shading in a mask. is obtained.

In recent years, particularly in the manufacture of semiconductor devices that require fine patterns, electron beam lithography equipment has been introduced to photomask production due to advances in the development of electron beam exposure technology, and photomasks with highly accurate fine patterns have been obtained.

For this reason, at present, if a high degree of dimensional accuracy is required for the guide grooves, a photomask with a guide groove pattern drawn using the above-mentioned electron beam lithography system is used. It is desirable to create one. Furthermore, if a method superior to this method is developed and put into practical use, it would of course be desirable to use that method to produce masks.

ii) Preparation of master disc A resist master disc is manufactured using a mask having a pattern in which guide grooves are present at regular intervals within the recording area of the optical card.

Metals and resins are also considered as the base material (original plate) for forming resist patterns, but they have the advantage of being relatively easy to process with high surface accuracy, and are stable materials.
Glass, which is commonly used, is currently the best choice. In order to improve the smoothness of the surface of the glass plate used as the original plate, it is sufficiently polished, the abrasive material is then removed, and pretreatment is performed such as ultrasonic cleaning, cleaning with an organic solvent, etc.

Next, a resist is applied to form a pattern of guide grooves on the original plate.

Types of resist include regular ultraviolet irradiation type resist, D
There are eep UV (deep ultraviolet) resists, electron beam resists, X-ray resists, etc., and the light source used and the resist that can precisely and accurately reproduce the guide groove pattern are selected and used. Among these, those that can be handled relatively easily including exposure equipment are ordinary ultraviolet irradiation type photoresists.

Generally, positive-type materials in which the exposed areas dissolve during development are often used. Typical examples include the AZ series (manufactured by Hoechs), the former cro Po5jt
series (Shipley), 0FPR series (
Tokyo Ohka), KMPR series (Kodak), etc. Although it cannot necessarily be said to be superior in terms of chemical resistance and adhesion to the glass base plate compared to the negative type (the exposed area hardens), it is superior in terms of resolution and is suitable for forming fine patterns. It is often used for forming.

There are various methods for applying photoresist, such as the tapping method, roller coater method, and spraying method, but the spinning method, in which the resist dropped onto a glass plate is scattered by the centrifugal force of rotation and a film is formed on the glass surface, is superior in its precision and accuracy. This is a desirable method because of its practical simplicity. The film thickness can generally be controlled by the resist concentration and spinner rotation speed.
The resist can be applied to the desired H thickness. Also, in general, the adhesion between glass and photoresist is not good, so
Before application, the glass surface is treated with a surface modifier to strengthen adhesion. The composition of positive resist is generally
Since it is composed of a quinone diazide photodegrading agent, a phenol novolak resin, and a solvent, it exhibits hydrophobicity, so it improves adhesion by modifying the glass surface to be hydrophobic.
As a surface modifier, silane coupling agents such as hexamethyldisilazane and organic chlorosilane are effective.

Generally, the thickness of the resist coating is matched to the required depth of the guide groove. Another method is to control the exposure amount so that the resist is removed by the depth of the guide groove, but this requires quite advanced technology.

After coating, a prebater is performed to remove the solvent from the coating film, and then exposure is performed using a mask on which a pattern of guide grooves is drawn. There are two types of exposure apparatus: a contact type and a projection type, and either type may be used as long as the pattern of the guide groove can be printed with high precision and accuracy.

After exposure, the resist is developed to obtain a glass master (resist master) on which a pattern of guide grooves is formed on the glass plate. This is currently a relatively simple method for producing a master disc, but the resist used, exposure method, etc. are not limited to the above methods, and in short, the desired guide groove pattern, preformat pattern, etc. Any combination may be used as long as the master on which the images are drawn can be produced with high precision and accuracy, and can be produced in basic photolithography facilities and ordinary experimental facilities.

ji) Preparation of guide grooves It is preferable to use the general nickel electroforming method to create a stamper from the resist master (glass master), but this is not limited to this method. It is fine as long as the properties are good.

Compression molding is used to create guide grooves from the stamper in plastic. In optical discs, guide grooves are produced by injection molding, but since it is difficult to mold plastic with a thickness of 1 ffII or less using this method, compression molding is used. The plastic used is preferably a thermoplastic resin such as polyvinyl chloride, polycarbonate, polymethyl methacrylate, or polyolefin.

This will be explained in detail below.

Figure 1 shows pattern 1 of a plan view of the optical recording section of an optical card.
FIG. The guide grooves 2 have a width of 2.5 μm and are arranged at a pitch of 12 μm. In the drawing, preformat pattern 3 exists near the left end. These patterns are printed on a chrome mask 4 using an electron beam lithography system.
Copy to.

Figure 2 shows the steps of the resist master production method.
(a) shows the master disc before exposure, and a resist layer 6 is laminated on the surface of the glass plate 5. The surface of the glass plate 5 is thoroughly polished using cerium oxide (CeOz) as an abrasive to improve its smoothness, and after removing the abrasive, it is subjected to ultrasonic cleaning,
It was washed with dilute hydrochloric acid and distilled water, and thoroughly dried. Regis) J1i6 was coated with Z-1350 to a thickness of 0.07 μm using spin coke. Before coating, spread primer F-20 on the surface and apply at 2000rpm.
Surface modification was performed by spinning the glass plate for 20 seconds.

Resist (AZ-1350) coating conditions are AZ-135
0 to a solid content of 9% with AZ thinner and 200 rpm.
The film was formed for 30 seconds. And 80°C%
A 20m+n pre-beta was performed.

In FIG. 1B, the pattern of the guide groove 2 and the exposure trace of the preformat pattern 3 are formed in the resist layer 6 using a chrome mask 4 using a contact type exposure device. (G)) for 40 to 60 seconds with a 2-fold diluted developer (MF2412).
After development, a glass master (resist master) 7 was obtained. (
C) Gold was deposited to a thickness of 1,000 yen on the glass master (resist master) 7 to form a conductive film, and a stamper 8 was manufactured by electroforming using a nickel sulfamate bath.

A polymethacrylic acid film with a thickness of 0.4 m is placed on the stamper 8.
- Heat press at about 150℃ with chill sheet 9 (about 10
kg/C1M) and the guide groove 2 was produced. (d)
<Effects of the Invention> According to the present invention, a resist master disk in which a plan view pattern of an optical recording section including a guide groove (pre-group) which has not yet been externally written is copied in a basic photolithography facility and a normal experimental facility. (glass master) is easily obtained, from which guide grooves can be easily replicated in plastic.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram showing a pattern in a plan view of an optical recording section of an optical card, and FIG. 2 is an explanatory diagram showing a method for producing a resist master disk. 1: Pattern of plan view of optical recording section of optical card 2: Guide groove 3 Pattern of nib reformat 4 Nichrome mask 5 Glass plate 6: Resist layer 7: Glass master (resist master) 8 Nistamper 9: Polymethyl methacrylate Sheet patent application Representative Kazuo Suzuki, Toppan Printing Co., Ltd.

Claims (1)

[Claims] In a method of manufacturing a guide groove for an optical card, which is provided for accurately positioning a recording spot in an optical recording part of an optical card, a resist is applied on a highly smooth substrate, and a predetermined pattern of an optical recording part including the guide groove is manufactured. A resist pattern is formed on the substrate by exposure using a mask having a mask, and then developed to form a resist pattern replicating the predetermined pattern on the substrate to produce a resist master, and compression molding is performed using a stamper made from the resist master, A method for manufacturing a guide groove for an optical card, the method comprising forming a guide groove.