JPS62281137A - Manufacture of disk-shaped storage medium - Google Patents

Abstract

PURPOSE:To uniformize the thickness of a vacant part between two sheets of substrates, and to reduce dispersion in the thickness of a medium itself, by stacking temporarily both substrates by an adhesive in which a spacer member is mixed. CONSTITUTION:A pair of adhesive layers 6a, 6b, of halfcircular arc shape along the outer peripheral edge part of a recording layer 3 in a first transparent substrate 1, and an annular sticking agent layer 6b along the peripheral edge part of an aperture hole 7a, are coated and formed, respectively. Next, the recording layers 3 and 4 of the first transparent substrate 1 and a second transparent substrate 2 are confronted and overlapped, and pressurization is applied on both transparent substrates so as to be sandwiched from both outsides, and afterwards, an element main body is formed by curing, the adhesive layers 6a and 6b, and sticking temporarily both transparent substrates 1 and 2 integrally. In such case, since spacer members 11, 11... are mixed in the adhesive layers 6a and 6b, the thickness of a vacant part 8 is regulated by the spacer member 11, and the thickness almost equal to the diameter of the spacer member 11 can be formed.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a disc-shaped storage medium, and in particular, the present invention relates to a method of manufacturing a disk-shaped storage medium, and in particular, recording 117 lines with light such as a laser beam, or recording. It is used to manufacture optical memory devices that reproduce and erase stored information.

(Prior Art) In recent years, research and development of optical memory devices has been actively conducted amid increasing demand for storage devices capable of large capacity, high density, and high-speed access.

FIG. 8 shows a partial cross-sectional structure of a conventionally proposed optical memory element that can also erase information.

In the figure, a and e are two transparent substrates made of synthetic resin such as PMMA (polymethyl methacrylate) or glass, respectively, b and d are single-layer magnetic films, dielectric films, magnetic films, reflective films, etc. The recording layer is a multilayer film made of a film or the like, C is an adhesive layer, and r is a center hole.

A conventional optical memory element with such a configuration includes a transparent substrate a,
By stacking two sheets of e, information can be stored 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 an advantage that changes in shape such as warpage of the transparent substrates can be suppressed.

(Problem that the invention attempts to solve) However, such two transparent substrates a.

Conventionally, bonding of the recording layer C was carried out by a spray method, a roll coater method, etc., which caused the problem that air bubbles remained in the adhesive layer C, and these air bubbles adversely affected the characteristics and long-term reliability of the recording layer C. Ta. In order to solve this problem, a cavity is formed between two substrates having recording layers to be filled with the adhesive that bonds these substrates together, and this cavity is filled with the adhesive by some method. This is a possible method.

However, when this method is used, variations in the thickness of the cavity formed between the side substrates tend to occur (this has the problem of increasing variations in the thickness of the formed optical memory element itself).

(Means for Solving the Problems) The method for manufacturing a disc-shaped storage medium according to the present invention has been made in view of the above points, and includes a disc-shaped first substrate and a second disc-shaped substrate each having an opening in the center. a step of forming a recording layer on each side; and a step of forming a recording layer on at least one of the first substrate and the second substrate on which the recording layer is formed, the outer peripheral edge of the surface on which the recording layer is formed and the opening peripheral edge of the substrate. A step of applying an adhesive mixed with a spacer member to the portion by screen printing method, and after applying the adhesive, overlapping the first substrate and the second substrate with the recording layer facing each other, and forming both plates. A step of applying pressure to sandwich both types of plates from the outside to obtain a thickness determined by the spacer member, and after obtaining the thickness, curing the adhesive with heat or light to cure the first substrate. and a step of integrating the second substrate; and a step of curing the adhesive and then filling an empty space surrounded by the first substrate, the second substrate, and the cured adhesive with the adhesive. and curing the filled adhesive with light or heat.

(Function) An adhesive mixed with a spacer member is applied to the outer periphery of the surface on which the recording layer is formed and the opening periphery of at least one of the substrates, and when both types of plates are bonded under pressure in this state, the adhesive The width of the space formed between the side substrates is always determined to be a constant width by the spacer member mixed in the spacer member. Thereby, variations in the thickness of the optical memory element itself, which is formed by filling the void with adhesive and curing it, can be suppressed to a small level.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

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

In the figure, reference numeral 1.2 denotes a first transparent substrate and a second transparent substrate, which are arranged opposite to each other with a constant interval, and each is formed into a disk shape with an opening hole 7a, 7b in the center. A recording layer 3° 4 is formed on each opposing surface of the first J-light substrate 1 and the second transparent substrate 2, and these recording layers 3,
Adhesive layers 6a and 6b for temporarily bonding both transparent substrates 1.2 are formed between the two transparent substrates 1.2. Is one of the adhesive layers 6a and 6b an open hole? a, 7b, and the other adhesive layer 6a is applied to the transparent substrate 1.2.
coated on the outer periphery of the

Further, a spherical spacer member 11 is attached to the adhesive layers 5a and 6b.
．． A large number of li... are mixed into the image recording layers 3 and 4.
The thickness of the cavity 8 formed by the adhesive layers 5a and 5b is determined by the spacer member 11. That is, the thickness of the cavity 8 is approximately equal to the diameter of the spacer member 11. By filling the cavity 8 thus formed with the adhesive 5, both transparent substrates 1.2 are integrally bonded and fixed by the adhesive 5.

The materials of the first transparent substrate 1 and the second transparent substrate 2 are as follows:
For example, synthetic resin such as PMMA or glass is suitable. Further, the recording layer 3.4 is formed of a single-layer magnetic film or a multilayer film consisting of a dielectric film, a magnetic film, a reflective film, and the like. However, the recording layer 3.4 may be formed of a Te-based material, an organic dye, or the like.

Next, a procedure for manufacturing the optical memory element having the above configuration will be explained.

A recording layer 3 is formed on each side of the first transparent substrate 1 and the second transparent substrate 2, which are disk-shaped and have openings 7a and 7b in the center.
form 4. Next, on at least one substrate (for example, the first transparent substrate 1) on which the recording layer is formed, a pair of adhesive layers 6a having a semicircular arc shape are applied along the outer peripheral edge of the recording layer 3 of the first transparent substrate 1. , 6a, and an annular adhesive layer 6b along the periphery of the opening hole 7a, respectively, are formed by coating by screen printing. The first transparent substrate 1 and the second transparent substrate 2 on which the adhesive layers 6a and 5b are formed in this way are recorded at N3.
, 4 are stacked facing each other, and in this state, pressure is applied from both outsides of both transparent substrates 1.2 so as to sandwich these two transparent substrates 1.2, and then the above-mentioned adhesive is bonded by means such as light or heat. By curing the agent layers 6a and 6b, both transparent substrates 1,
2 are temporarily bonded together to form an element body 20 (see FIGS. 1 and 2). A portion surrounded by both transparent substrates 1 and 2 and adhesive layers 6a and 6b is covered with another adhesive 5, which will be described later.
This becomes a cavity 8 for filling. At this time, the adhesive layer 5
Since the spacer members 11, 11, . Further, the pair of adhesive layers 6a, 6a formed on the outer peripheral edge of the first transparent substrate 1 are arranged so as to create 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 main body 20 formed as described above is immersed in the adhesive 5 stored in the adhesive tank 10 with the suction hole 9b facing down, and the air in the cavity 8 is exhausted through the exhaust hole 9a. As a result, the adhesive 5 in the adhesive tank 10 is drawn from the suction hole 9b into the empty space 8.
The adhesive 5 is sucked up into the cavity 8 and filled with the adhesive 5 (see FIG. 3).

Thereafter, the adhesive 5 filled in the cavity 8 is cured by means such as light or heat, and the bonding work is completed.

In the above embodiment, the adhesive layer 6a formed by screen printing is formed into a semicircular arc shape as shown in FIG. 2, but the shape of the adhesive layer 6a is not limited to this. For example, the adhesive layer 1 is shaped like the one shown in FIG.
6a may be formed by screen printing. In this case, as shown in FIG. 5, after first exhausting the air in the cavity 18 through the through hole 19,
The adhesive 5 may be filled into the cavity 18 using the difference between the atmospheric pressure applied to the surface of the adhesive 5 and the pressure inside the cavity 18 .

Further, for example, as shown in FIG. 6, at least one of the first transparent substrate 1 and the second transparent substrate 2 is provided with a through hole 29 penetrating through the substrate itself, and an adhesive layer 26a is formed on the outer peripheral edge. may be circular. In this case, the adhesive 5 may be filled into the cavity 28 and cured using any of the methods described above.

Moreover, each adhesive layer 6a, 16a as mentioned above.

When forming the adhesive layer 26a by screen printing, as shown in FIG. 7, the adhesive layer 6 a <16 a, 26
It is also possible to provide information such as product lot number or design 30 in a).

(Effects of the Invention) As explained above, according to the present invention, by temporarily bonding two substrates with an adhesive mixed with a smoother member, the thickness of the void formed between the two substrates is made uniform. Therefore, it is possible to easily and reliably manufacture a disc-shaped storage medium (optical memory element) with little variation in the thickness of the medium itself.

[Brief explanation of the drawing]

1 to 7 show an embodiment of the 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 element manufactured by the manufacturing method of the present invention, The figure is a plan view of the element body before being filled with adhesive, FIG. 3 is a schematic configuration diagram of the element body immersed in an adhesive layer, and FIG. 4 is a plan view showing another embodiment of the element body. 5 is a schematic configuration diagram of the element body shown in FIG. 4 dipped in adhesive, FIG. 6 is a plan view showing still another embodiment of the element body, and FIG.
The figure is a plan view showing how information such as a lot number is provided on the adhesive layer provided on the outer periphery, and FIG. 8 is a partial vertical cross-sectional view of an optical memory element manufactured by a conventional manufacturing method. 1... First transparent substrate 2... Second transparent substrate 3.4
...Recording layer 5...Adhesive 6a, 6bA6
a, 26a --- Adhesive layer "la," lb --- Opening hole 8.18.28... Hole 9a... Exhaust hole
9b...Suction hole 19.29...Through hole
10... Adhesive tank 11... Spacer member
20...Element body 1 Figure 7b 6b 5 Figure 2 η a Figure 4 Figure 6

Claims (1)

[Scope of Claims] 1) Forming a recording layer on one side of each of a disk-shaped first substrate and a second substrate having an opening at the center; a step of applying an adhesive mixed with a spacer member to at least one of the substrates on the outer periphery of the surface on which the recording layer is formed and the opening periphery of the substrate by a screen printing method; and applying the adhesive. After that, the first substrate and the second substrate are overlapped with the recording layers facing each other, and pressure is applied from the outside of both substrates so as to sandwich these substrates, thereby creating a thickness determined by the spacer member. After increasing the thickness, the adhesive is cured by heat or light to integrate the first substrate and the second substrate; After the adhesive is cured, the adhesive and the first substrate are cured. A disc-shaped storage medium comprising the steps of: filling another adhesive into a cavity surrounded by a substrate and the second substrate; and curing the filled adhesive with light or heat. manufacturing method. 2) The method for manufacturing a disc-shaped storage medium according to claim 1, wherein the spacer member is transparent. 3) A method for manufacturing a disk-shaped storage medium according to claim 1, wherein information such as a lot number is provided on an adhesive layer formed on the outer peripheral edge of the substrate. 4) A method for manufacturing a disc-shaped storage medium according to claim 3, wherein information such as a lot number is provided by a screen printing method.