JPH0750535B2 - Disk-shaped storage medium manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a disk-shaped storage medium, and particularly to recording information with light such as laser light, or reproducing / erasing recorded information. It is used for manufacturing an optical memory device.

(Prior Art) In recent years, research and development of optical memory devices have been actively conducted in response to a growing demand for storage devices capable of high-capacity, high-density, and high-speed access.

FIG. 8 shows a partial cross-sectional structure of an optical memory device capable of erasing information which has been conventionally proposed.

In the figure, a and e are two transparent substrates made of synthetic resin such as PMMA (polymethylmethacrylate) or glass, and b and d are single-layer magnetic films, or dielectric films, magnetic films, and reflection films, respectively. The recording layer is a multi-layered film including a film, c is an adhesive layer, and f is a central hole.

The conventional optical memory device having such a configuration has the transparent substrates a and e.
By stacking two sheets, information can be put on both sides of the disk, which has the advantage of doubling the amount of information per disk. Further, when a synthetic resin such as PMMA is used for the transparent substrates a and e, there is also an advantage that it is possible to suppress a change in shape such as a warp of the transparent substrate.

(Problems to be Solved by the Invention) However, since the two transparent substrates a and e have been conventionally bonded by a spray method, a roll coater method, or the like, bubbles remain in the adhesive layer c, There is a problem that these bubbles adversely affect the characteristics and long-term reliability of the recording layers b and d. In order to solve this problem, a space for filling an adhesive for adhering these substrates is formed between two substrates having a recording layer, and the space is filled with the adhesive by some method. That method is possible. However, in the case of this method, there is a problem in that the thickness of the void formed between both substrates is likely to vary, which causes a large variation in the thickness of the formed optical memory element itself.

(Means for Solving Problems) The method for manufacturing a disk-shaped storage medium according to the present invention has been made in view of the above point, and each of a disk-shaped first substrate and a second substrate having an opening at the center thereof. A step of forming a recording layer on one surface respectively, and an outer peripheral edge portion and an opening peripheral edge of a surface of the substrate on which the recording layer is formed, on at least one of the first substrate and the second substrate on which the recording layer is formed. A step of applying an adhesive agent in which a spacer member is mixed to a portion by a screen printing method, and after applying the adhesive agent, the first substrate and the second substrate are overlapped with the recording layers facing each other, and the outside of both substrates From the first substrate and the front substrate by applying pressure so as to sandwich these two substrates to obtain a thickness determined by the spacer member, and after the thickness is produced, the adhesive is cured by heat or light. A step of integrating the second substrate, and a step of filling the adhesive in a space surrounded by the first substrate and the second substrate and the cured adhesive after the adhesive is cured, And a step of curing the filled adhesive with light or heat.

(Operation) When an adhesive agent containing a spacer member is applied to the outer peripheral edge portion and the opening peripheral edge portion of the surface of at least one of the substrates on which the recording layer is formed, if both substrates are pressure-bonded in this state, the adhesive agent Due to the mixed spacer member, the width of the void formed between the two substrates is always fixed. As a result, it is possible to suppress variations in the thickness of the optical memory device itself formed by filling the voids with an adhesive and curing the adhesive.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

FIG. 1 shows the structure of an optical memory device manufactured by the manufacturing method of the present invention.

In the figure, reference numerals 1 and 2 denote a first transparent substrate and a second transparent substrate, which are arranged to face each other with a constant spacing, and are formed in a disk shape having opening holes 7a and 7b at the centers thereof. Recording layers 3 and 4 are formed on the opposing surfaces of the first transparent substrate 1 and the second transparent substrate 2, respectively, and an adhesive for temporarily adhering the transparent substrates 1 and 2 between the recording layers 3 and 4. Agent layers 6a and 6b are formed. One of the adhesive layers 6a and 6b is disposed (applied) on the peripheral portion of the opening holes 7a and 7b, and the other adhesive layer 6b.
a is disposed (applied) on the outer peripheral edges of the transparent substrates 1 and 2.
Further, a large number of spherical spacer members 11, 11 ... Are mixed in the adhesive layers 6a, 6b, and the thickness of the void portion 8 formed by both recording layers 3, 4 and the adhesive layers 6a, 6b is This spacer member 11
Determined by That is, the thickness of the void portion 8 is substantially equal to the diameter of the spacer member 11. By filling the adhesive 5 in the space 8 formed in this way, both transparent substrates 1 and 2 are integrally bonded and fixed by the adhesive 5.

As the material of the first transparent substrate 1 and the second transparent substrate 2,
For example, synthetic resin such as PMMA or glass is suitable. The recording layers 3 and 4 are a single-layer magnetic film or a dielectric film,
It is formed of a multilayer film including a magnetic film, a reflective film, and the like. However, the recording layers 3 and 4 may be formed of a Te-based material, an organic dye, or the like.

Next, a procedure for manufacturing the optical memory device having the above configuration will be described.

Recording layers 3 and 4 are formed on one side of each of a disk-shaped first transparent substrate 1 and a second transparent substrate 2 having opening holes 7a and 7b in the center. Next, on at least one substrate (for example, the first transparent substrate 1) on which the recording layer is formed, a pair of semi-arcuate adhesive layers 6 along the outer peripheral edge of the recording layer 3 of the first transparent substrate 1.
a, 6a, and an annular adhesive layer along the periphery of the opening hole 7a
6b is applied and formed by a screen printing method.
The first transparent substrate 1 on which the adhesive layers 6a and 6b are formed in this way
And the second transparent substrate 2 are superposed with the recording layers 3 and 4 facing each other, and in this state, pressure is applied from both outsides of the transparent substrates 1 and 2 so as to sandwich the transparent substrates 1 and 2. After this,
The adhesive layers 6a and 6b are cured by means such as light or heat, and the two transparent substrates 1 and 2 are integrally and temporarily adhered to each other.
0 is formed (see FIGS. 1 and 2). Both transparent substrates
A portion surrounded by 1, 2 and the adhesive layers 6a, 6b becomes an empty portion 8 for filling another adhesive 5 described later. At this time, since the spacer members 11, 11 ... Are mixed in the adhesive layers 6a, 6b, the thickness of the empty portion 8 is regulated by the spacer member 11 and becomes substantially equal to the diameter of the spacer member 11. . Further, the pair of adhesive layers 6a, 6a formed on the outer peripheral edge portion of the first transparent substrate 1 are arranged so as to form a gap between their ends, and one of these gaps is the exhaust hole 9a, The other becomes the suction hole 9b.

Next, the element body 20 formed as described above is attached to the adhesive tank 10
Immerse it in the adhesive 5 stored inside with the suction hole 9b facing down,
The air in the empty space 8 is exhausted from the exhaust hole 9a, whereby the adhesive 5 in the adhesive tank 10 is sucked up into the empty space 8 from the suction hole 9b, and the empty space 8 is filled with the adhesive 5. (See Figure 3).
After that, the adhesive 5 filled in the space 8 is cured by means of light or heat, and the bonding work is completed.

Although the adhesive layer 6a formed by the screen printing method is formed in a semi-circular shape as shown in FIG. 2 in the above embodiment, the shape of the adhesive layer 6a is not limited to this. For example, the adhesive layer 16a may be formed in a shape as shown in FIG. 4 by a screen printing method. In this case, as shown in FIG. 5, first, the air in the void 18 is exhausted from the through hole 19, and then the through hole 19 is immersed in the adhesive 5 in the adhesive tank 10 to remove the adhesive 5. The space 5 may be filled with the adhesive 5 by utilizing the difference between the atmospheric pressure applied to the surface and the pressure inside the space 18.

Further, for example, at least one of the first transparent substrate 1 and the second transparent substrate 2 has a through hole 29 penetrating the substrate itself as shown in FIG. May have a ring shape. In this case, the adhesive 5 may be filled in the void 28 and cured by any of the above methods.

When the adhesive layers 6a, 16a and 26a are formed by the screen printing method as described above, as shown in FIG.
It is also possible to provide information such as the lot number of the product or the design 30 on 6a (16a, 26a).

(Effects of the Invention) As described above, according to the present invention, by temporarily adhering two substrates with an adhesive containing a spacer member, the thickness of the void formed between both substrates is made uniform. As a result, a disk-shaped storage medium (optical memory element) with little variation in the thickness of the medium itself can be manufactured easily and reliably.

[Brief description of drawings]

1 to 7 show an embodiment of a method for manufacturing a disk-shaped storage medium according to the present invention, and FIG. 1 is a partial longitudinal sectional view of an optical memory device manufactured by the manufacturing method according to the present invention. FIG. 4 is a plan view of the element body before being filled with an adhesive, FIG. 3 is a schematic configuration view of the element body immersed in an adhesive layer, and FIG. 4 is a plan view showing another embodiment of the element body. FIG. 5 is a schematic configuration diagram of the element body shown in FIG. 4 immersed in an adhesive, FIG. 6 is a plan view showing still another embodiment of the element body, and FIG.
FIG. 8 is a plan view showing a state in which information such as a lot number is provided on an adhesive layer provided on the outer peripheral edge portion, and FIG. 8 is a partial vertical cross-sectional view of an optical memory element manufactured by a conventional manufacturing method. 1 ... 1st transparent substrate, 2 ... 2nd transparent substrate 3, 4 ... recording layer, 5 ... adhesive 6a, 6b, 16a, 26a ... adhesive layer 7a, 7b ... opening hole, 8, 18,28 …… Empty part 9a …… Exhaust hole, 9b …… Suction hole 19,29 …… Through hole, 10 …… Adhesive tank 11 …… Spacer member, 20 …… Element body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Washo 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Akira Takahashi 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Kenji Ota 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture

Claims (4)

[Claims] 1. A step of forming a recording layer on each of one surfaces of a disk-shaped first substrate and a second substrate having an opening at the center, and at least the first substrate or the second substrate on which the recording layer is formed. A step of applying an adhesive agent containing a spacer member to the outer peripheral edge portion and the opening peripheral edge portion of the surface of the substrate on which the recording layer is formed by a screen printing method; A step of stacking the first substrate and the second substrate with layers facing each other, and applying a pressure from the outside of both substrates so as to sandwich these substrates, thereby obtaining a thickness determined by the spacer member; And then curing the adhesive with heat or light to integrate the first substrate and the second substrate, and after curing the adhesive, the adhesive and the first substrate and the First 2. A method of manufacturing a disk-shaped storage medium, comprising: a step of filling another space between the two substrates with another adhesive; and a step of curing the filled adhesive with light or heat. 2. The method for manufacturing a disk-shaped storage medium according to claim 1, wherein the spacer member is transparent. 3. An adhesive layer formed on an outer peripheral edge portion of a substrate, wherein information such as a lot number is provided.
A method for manufacturing a disk-shaped storage medium according to item. 4. A method of manufacturing a disk-shaped storage medium according to claim 3, wherein information such as lot number is provided by a screen printing method.