JPH0411930B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] Since the adhesive that takes a long time to harden is used to bond the transfer mold body of the optical disk and the centering plate, the positional shift may occur after the alignment work and before it hardens. Although there are some problems that may occur, there is a method to prevent misalignment by applying quick-drying adhesive and fixing it after alignment.

[Industrial application field]

The present invention relates to a method for manufacturing an optical disk transfer mold with high eccentricity accuracy.

Optical disks are memory that uses laser light to record high-density information, and have excellent features such as large storage capacity, non-contact recording and playback, and being unaffected by dust. ing.

In other words, the diameter of the laser beam is approximately
It is possible to focus on a spot as small as 1 μm, and therefore the area required to record 1 bit of information is only about 1 μm ² .

Therefore, the area required for recording one bit of information on a magnetic disk or magnetic tape is much smaller than that of several tens to ^several hundreds of micrometers, and therefore, large-capacity recording is possible.

Such optical disks are made of polymethyl methacrylate (abbreviated as PMMA) or polycarbonate (abbreviated as PC).
On a transparent substrate made of plastic or glass, there is a resin layer provided with a guide groove (pre-groove) indicating the recording position of information, and a recording layer is formed on this resin layer.

Information is recorded and reproduced by projecting a laser spot onto the recording layer through the transparent substrate.

Here, the resin layer provided with the guide grooves is formed by casting resin onto a stamper in which the guide grooves have been molded in advance.

The present invention relates to a method for forming a transfer mold to which such a stamper is adhered with high eccentricity accuracy.

[Conventional technology]

FIG. 1 shows a conventional method of adhesively fixing an optical disk transfer mold main body 1 to a centering plate 2 using a room temperature curing adhesive 3.

Here, the transfer form 1 consists of a stamper 4 and a backing plate 5, and the method of forming this will be explained as follows.

A photoresist (for example, positive type) is applied to a thickness of about 0.1 μm on a glass disk, and an argon (Ar) laser is scanned onto the photoresist to selectively expose a guide groove pattern (pregroove pattern).

This is developed to create a glass master disk with a concave guide groove pattern, and then nickel (Ni) is deposited on this glass master disk, Ni electroforming is applied, and this is peeled off from the glass master disk to form the stamper 4. be done.

Next, this stamper is attached to a backing plate 5 made of glass.
The transfer mold main body 1 is formed by adhering to.

Such a transfer mold main body 1 has a centering plate 2 prepared separately.
A room-temperature curing adhesive (for example, epoxy adhesive) is used to bond between the two, and highly accurate centering is performed until it hardens.

The method is to
This is done by placing the mold on a rotary table, aligning the center of rotation with the centering plate 2, and then aligning the guide groove of the transfer mold body 1.

Note that during this operation, the room-temperature curing adhesive is not cured, and it is possible to perform the centering operation sufficiently.

However, since it takes a considerable amount of time for the alignment to be completed and for the adhesive to harden, there has been a problem in that the positional relationship may shift during that time.

There is also a method of mechanically fixing the two after alignment, but there is a problem in that positional deviation occurs when fixing.

[Problem that the invention seeks to solve]

As explained above, the transfer mold body 1 is moved to the centering plate 2.
It is easy for the position to shift when fixing with adhesive,
It is necessary to find ways to prevent this.

[Means for solving problems]

The above problem was solved by joining the disc-shaped transfer mold body 1 with a center hole and the disc-shaped centering plate 2 with a center hole through an uncured room-temperature curing adhesive. After setting it on a rear rotary table and aligning the center of rotation of the rotary table with the centering plate 2, the room-temperature curing mold is In the method of manufacturing an optical disk transfer mold in which the adhesive is cured and the transfer mold main body 1 is fixed to the centering plate 2, between the centering step and the fixing step by curing the room temperature curing adhesive. In order to prevent misalignment of the aligned transfer mold main body 1 and centering plate 2, a method is adopted which includes a temporary fixing step by hardening and fixing a quick-drying adhesive applied to the circumferential edge of the joint boundary. It can be solved.

[Effect]

In the present invention, as shown in FIG. 2, before performing the alignment work between the transfer mold body 1 and the centering plate 2, an ultraviolet curing adhesive 6 is applied in advance to the joints of the edges at equal intervals. After alignment, it is irradiated with ultraviolet light to harden and fix.

A similar fixing effect can be obtained by applying an instant curing adhesive to this joint after alignment.

〔Example〕

Example 1 A transfer mold body made by gluing a stamper with a diameter of 14 inches to a backing plate made of a glass plate was made into a mold body with the same diameter and thickness using an epoxy room-temperature curing adhesive as shown in Figure 1. Pressure bonded with a 5mm centering plate.

After applying an acrylic acid ester ultraviolet curable adhesive at equal intervals (four locations in this case) to the joints between the two, this was placed on a rotary table and aligned.

Next, after the centering process was completed, the ultraviolet curable adhesive was cured by irradiating it with ultraviolet rays of 400 mW/cm ² for 30 seconds, and then left overnight to cure the internal adhesive at room temperature.

The centering member 7 was fitted into the inner diameter of the centering plate of the transfer mold thus obtained.

At this time, the centering member 7 protrudes 1 mm from the stamper.

The optical disk substrate was manufactured as follows.

Approximately 2 c.c. of ultraviolet curing resin is applied onto the transfer stamper.
A transparent substrate was placed thereon so that its inner diameter would fit with the centering member 7, and pressure was applied to spread the ultraviolet curing resin between the substrate and the transfer mold.

Next, the resin was cured by irradiating ultraviolet rays from the transparent substrate side, and then peeled off at the interface with the transfer mold to obtain an optical disk substrate having pregrooves.

At this time, the eccentricity between the inner diameter of the optical disk substrate and the pregroove was about 10 μm.

In addition, in this example, the centering plate was glued to the transfer mold and then the centering jig was attached, but even if the centering jig was attached and then the centering plate was aligned with the upper groove of the transfer die. good.

Example 2 A transfer mold main body and a centering plate having the same dimensions as in Example 1 were similarly bonded using an epoxy room-temperature curing adhesive, placed on a rotary table, and aligned in the same manner as before. After that, an instant adhesive (trade name: Aron α) was applied to the bonded portions of the two at equal intervals (four locations in this case) to fix them.

Then, they were left together overnight to allow the room temperature curing adhesive inside to harden, completing the adhesion.

When the degree of eccentricity between the inner diameter and the guide groove of the transfer mold thus obtained was measured, it was as small as about 10 μm.

〔Effect of the invention〕

As described above, by carrying out the present invention, it is possible to prevent positional deviation after alignment, thereby making it possible to improve eccentricity accuracy.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the bonding process between the transfer mold body and the centering plate, and FIG. 2 is a sectional view illustrating the positioning and fixing method according to the present invention. In the figure, 1 is the transfer mold body, 2 is the centering plate,
3 is a room temperature curing adhesive, 4 is a stamper, 5 is a backing plate, and 6 is an ultraviolet curable adhesive.

Claims (1)

[Claims] 1. A disc-shaped transfer mold main body 1 provided with a center hole and a disc-shaped centering plate 2 provided with a center hole for centering are bonded together using an uncured room-temperature curing adhesive. After joining, it is placed on a rotary table, and after aligning the center of rotation of the rotary table with the centering plate 2,
In the method for manufacturing an optical disk transfer mold, after the centering step of aligning the guide grooves of the transfer mold main body 1, the room temperature curing adhesive is cured and the transfer mold main body 1 is fixed to the centering plate 2. between the centering step and the fixing step by curing the room-temperature curing adhesive, a circumferential edge of the joining boundary part for preventing misalignment of the aligned transfer mold main body 1 and centering plate 2; 1. A method for manufacturing an optical disk transfer type, comprising a temporary fixing step by curing and fixing a quick-drying adhesive applied to the surface. 2 After the temporary fixing step joins the transfer mold main body 1 and the centering plate 2 using an uncured room temperature curing adhesive, an ultraviolet curable adhesive 6 is applied to the circumferential edge of the joining boundary. After the guide groove provided in the transfer mold main body 1 and the inner circumference of the centering plate 2 are aligned on the rotary table, the ultraviolet curable adhesive 6 is irradiated with ultraviolet rays. Claim 1 characterized in that it is cured and fixed by
A method for manufacturing an optical disk transfer mold as described in Section 1. 3. The optical disk transfer according to claim 1, wherein the temporary fixing step includes, after the centering step, applying an instant adhesive to the circumferential edge of the bonding boundary and curing it to fix it. Mold manufacturing method. 4. Claim 1, wherein the disc-shaped transfer mold body 1 is formed by adhering a disc-shaped stamper provided with a center hole to a disc-shaped glass plate provided with a center hole. A method for manufacturing an optical disk transfer mold as described in Section 1.