JPS6331042A - Optical information recording medium - Google Patents

Abstract

PURPOSE:To easily secure sufficient sticking strength without sacrificing a recording capacity by composing two substrates fore a first substrate and a second substrate with the outer diameter is smaller than the protruding part of the first substrate and forming the recording layer so as not to extend to the central hole and the protruding part of the first substrate and the central hole and the outer circumferential edge part of the second substrate. CONSTITUTION:A recording layer 3 is formed on substrates 1 and 2 and the outer diameter of the outer circumferential edge part of the second substrate 2 is smaller than a protruding part 11 of the first substrate 1. At the time of forming the recording layer 3, the protruding part 11 of the first substrate 1 and the outer circumferential edge part of the second substrate 2 and the vicinity of the central hole of respective substrates and masked and sputtered. Next, adhesives 5 are applied onto the recording layer 3 on the first substrate 1, the second substrate 2 is loaded on it so that two recording layer 3 can be faced, positioning is executed so that the position of respective central holes 4 can be coincident, two substrates 1 and 2 are pressured and the adhesives are charged between the substrates 1 and 2. By irradiating ultraviolet rays, adhesives 5 are hardened, a disk is completed and a bonding strength is secured.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is characterized in that when irradiated with light, a chemical change occurs in a physical state (by being irradiated with light), thereby recording, reproducing, erasing, etc. The present invention relates to a disk-shaped optical information recording medium that undergoes all of the above processes.

[Conventional technology]

In recent years, in the field of information recording, in addition to conventional magnetic recording, information recording that causes logical or chemical changes by irradiating light has become popular as non-volatile recording. Optical recording is being researched and put into practical use. For consumer use only for playback, home video discs, audio P
There are commercial discs, etc.

This optical recording is superior to Ike's recording method, lfi ege@ki recording, etc.

◎ Since the distance between recording tracks can be as close as 1 to 2 μm, high-density recording is possible.

◎ Due to contactless recording and playback, maintenance and handling are easy.

01 bit cost is low.

◎ Many types of recording media are disk-type, and access is much faster than other high-capacity recordings such as magnetic tape.

In the future, in an industrial society that will require extensive information recording, this is the ideal recording method.
Re-recordable optical recording has also reached the research and practical stage.

However, in optical recording, the bits are tiny and easily affected by dust, scratches, etc. during use, so two transparent substrates with a recording layer on at least one side are used, with the recording layer on the inside. The so-called air-sandwich type, which is bonded via a spacer or a convex portion provided on the substrate, or the so-called close bonding, where the entire surface is bonded directly with adhesive with the recording layer facing inside. Optical information recording media with structures such as a 9-way type have been proposed; in these structures, the recording layer is not exposed to the outside, so it is difficult to prevent dust, scratches, etc. from entering the recording layer. Can be done. In these Niga-style W-made optical information recording media, the recording layer, etc. is protected with adhesive, etc., so it is highly reliable in terms of weather resistance, etc., and is thinner. The structure of the 9-layer structure is excellent.

On the other hand, it is difficult to maintain sufficient adhesion between an inorganic layer such as a recording layer and an adhesive without impairing the performance of the recording layer, etc., and as a result, the optical information recording medium may lack strength. Therefore, a proposal has been made to improve the strength of the optical information recording medium by forming a recording layer in the center hole and near the outer peripheral edge of the substrate to ensure the adhesive force between the adhesive and the substrate.

JP-A-6O-5439).

[Problem that the invention seeks to solve]

However, the above-mentioned conventional technology has the following problems.

Factors that control adhesive strength include mechanical projection effect, van der Waals force, Coulomb force, entanglement between one molecule IA%
There are covalent bonds, etc., but in the above proposal, is the bonding area between the adhesive and the substrate where the molecular structure is more similar than that of the recording layer? By securing this, we expect effects such as entanglement between Van der Waal molecules, but increasing the area on the substrate where the recording layer is not formed will sacrifice the recording capacity of the optical information recording medium. Therefore, the non-recording layer area cannot be increased very much, and therefore it is difficult to ensure sufficient bonding strength.

The present invention is intended to solve these problems, and its purpose is to provide optical information that easily ensures sufficient bonding strength without sacrificing the recording capacity of the optical information recording medium. This is where the recording medium is provided.

[Means for solving problems]

The optical information recording medium of the present invention is capable of recording, reproducing, erasing information, etc. by irradiating at least one disk-shaped substrate with a center hole with light to cause physical and chemical changes in Al. Two substrates each having a recording layer subjected to any or all of the processes are provided.

An optical information recording medium in which an adhesive is filled between the two substrates without a gap so that the recording layer is sandwiched between the two substrates, and the protrusion of the first substrate. and a second substrate having an outer diameter smaller than that of the first substrate, and the recording layer is attached to the center hole and the protruding portion of the substrate for the first substrate, and to the center hole and the outer peripheral edge of the second substrate. The enemy is to form it in such a way that it does not lead to this.

[Implementation row]

@ Figure 1 is a cross-sectional view of an optical information recording medium (hereinafter referred to as a disk in the implementation row) in one embodiment of the present invention, and Figure 2 is an enlarged cross-sectional view of part A in Figure 1. . 1st
In the figure, 1 is a first substrate, 2 is a second substrate, both of which are made of plastic, and 4 is a center hole provided in both the first and second substrates. Further, 3 is a recording layer formed on the substrates 1 and 2, and the recording layer 3 is a Tb-F6-CO film formed by sputtering.
It is formed to have a thickness of about 000 (A).

By the way, as shown in FIG. 2, the first substrate 1 has a protrusion 11 at its outer peripheral end extending in the circumferential direction. Approximately 0.4 (
ax), and the width of the protrusion 11 is approximately 1.5 (
m). Further, the outer peripheral end portion of the second substrate 2 is
As shown in the figure, the outer diameter of the protrusion 11 of the first substrate 1 is
The difference is quite small, this time at 0.4-xB degrees. The external dimensions of the substrates 1 and 2 used this time are approximately 130 mm in outer diameter (
lJ), the diameter of the center hole 4 is about 15-g, and the thickness is about 1.2 (w), so the above-mentioned protrusion 11 with respect to the entire substrates 1 and 2
The proportion occupied by #1 substrate in an embodiment of the present invention 1.21-! , is manufactured by partially changing the existing molding die.

In the present invention, the protrusion l of the first substrate 1 and the outer peripheral edge of the second substrate 2 are bonded together by the adhesive 5 filled when the substrates 1 and 2 are pasted together. To work together to achieve the purpose of the invention.

When forming the recording layer 3 described above, the protrusion 11 of the first substrate 1, the outer peripheral edge of the second substrate 2, and the vicinity of the center hole of each substrate are masked and sputtered.

Next, an ultraviolet curing adhesive 5 is used to bond the first substrate 1 and the second substrate 2 together.

Apply adhesive 5 of a required grade onto the recording layer 3 on the first substrate l, place the second substrate 2 on top of it so that the recording layers 3 face each other, and adjust the position of each center hole 4. While aligning the positions so that they match, press the substrates 1 and 2 together and steam the rice 1,
Fill the space between the two with adhesive. Then, the adhesive 5 used this time is cured by irradiation with ultraviolet rays, and a disk is formed.

Furthermore, the implementation sequence of the present invention is not limited to the above, and the application sequence of the present invention when the recording layer 3 is formed only on one of two substrates is shown in FIG. In order to protect the recording layer 3 from the penetration of
FIG. 4 shows the application of the present invention when a layer (formed by sputtering) is formed between the recording layer 3 and the substrate, and -1
In addition to the row shown in FIG. 4, protection is provided between the adhesive 5 and the recording layer 3 in order to further protect against the penetration of moisture from the adhesive 5. The application column when forming 6 is the 5th
Furthermore, in order to eliminate the influence on the adhesive 5 caused by penetration of moisture from the substrate on which the recording layer 3 is not formed, the recording layer 3 is formed in addition to the rows shown in FIG. 5. FIG. 6 shows the application rows when the protective layer 6 is formed on the substrate, and the present invention has the same effect with these application rows. It goes without saying that the present invention can also be applied to the case where the structures of the recording layer 3 and the protective layer 6 shown in FIGS. 4 and 5 are symmetrical between the two substrates.

In addition, the plastics used for the substrates are made of a wide variety of materials.j) Some materials do not have good peelability from the mold during molding. FIG. 7 shows a row to which the present invention is applied when the protrusion 11 of the first substrate 1 is sloped, and a row to which the invention is applied when the outer peripheral end of the second substrate 2 is sloped is shown in FIG. 8, and FIG. 9 shows an application row in which both the protruding portion 11 of the female substrate 1 and the outer circumferential end of the second substrate 2 are sloped.

In addition, the original E! A C Bonding strength f depending on the shape of the board
It is related to ffl R, and the recording layer is Hsz,
F6, C1L, Mg, Zn, Cr
, N i , M W .

Tg, Bg, F3n, Gg, CQ, Engineering fi, Gd
, Sm, Dy, Md, Y, V, Tb, Ti, etc., consisting of a single or two or more compositions, B6°AJ,
8b, organic materials such as polyvinyl butyral, nitrocellulose, polyvinyl alcohol, l''jsi, AJ, Zt-, etc. as a protective layer.
Is there a similar effect with nitrides or oxides such as Ts, Btx, and CcL? have

〔Effect of the invention〕

In a closely bonded optical information recording medium, are the substrates so fragile? Since it is bonded, the only factor to ensure adhesive strength is the entanglement of one molecule by Fantearwall force, so it is particularly vulnerable to shearing force applied within the plane of the substrate, and has sufficient adhesion strength. secured light h
1 report recording medium g! However, according to the present invention, as described in 1 above, the protrusion of the first substrate and the outer peripheral end of the second substrate ? By bonding the adhesive and forming the bonded portion over almost the entire circumference of the optical information recording medium, even if shearing force is applied to the optical information recording medium, the bonded portion in the bonded portion will remain intact. The adhesive has a shape that resists compression force between the protruding portion of the first substrate and the outer peripheral edge of the second substrate, especially at the outer peripheral edge where shearing force is applied, and once cured, the adhesive can be compressed. As a result, it has the effect of ensuring sufficient bonding strength of the optical information recording medium, especially sufficient strength against shearing force.In addition, the protruding portion This also has the effect of preventing excess adhesive from flowing out to the outer circumferential edge since the space between the outer circumferential edge and the outer circumferential edge serves as an adhesive reservoir.

Brief Description of One Side FIG. 1 is an er side view of an optical information recording medium in a tM array of the present invention.

FIG. 2 is an enlarged sectional view of part A in FIG. 1.

Figures 3, 4, 5, 6, 7, 8, and 9 are cross-sectional views of an area of the pond according to the present invention.

1...First substrate 2...Second substrate 3--Fist recording layer 4...Central hole 5/Bite/adhesive 6...Protective layer 1]...Protrusion part or more Application Person: Seiko Epson Shiki Company Agent Patent Attorney Toki, 1,47 Affairs and 1 other person 1,'l,;
-:', 4 Figure 2 31 pieces

Claims (1)

[Claims] A recording layer that performs any or all of the processes of recording, reproducing, and erasing information by causing physical or chemical changes by irradiating at least one disk-shaped substrate with a central hole with light. comprising two substrates having at least
In an optical information recording medium in which an adhesive is filled between the two substrates without a gap so that the recording layer is sandwiched between the two substrates, the structure of the two substrates includes a protrusion at the outer peripheral edge. and a second substrate having a smaller outer diameter than the protruding portion of the first substrate, the recording layer being placed in the center hole of the substrate and the protruding portion of the first substrate, Further, the optical information recording medium is characterized in that the second substrate is formed so as not to reach the center hole and the outer peripheral edge.