JPH03173984A - Manufacture of information recording medium - Google Patents

Abstract

PURPOSE:To perform manufacturing with high dimension accuracy and productivity by joining a disk shape magnetosensitive hub with the inner peripheral part of a disk shape resin substrate, and joining obtained two resin substrates with hub by laminating by confronting their recording layers with each other. CONSTITUTION:A circular hole 2A is inserted to a disk connecting part 21 setting the recording layer 3A of the resin substrate 4A facing downward. Next, the hub 9A is placed on the substrate 4A by inserting a clamping hole 8A to a hub connecting part 23 setting a magnetosensitive material 7A facing upward. Next, the resin substrate with hub can be manufactured by descending the impression horn 26 of an ultrasonic welding machine 20, pressing the hub 9A, applying an ultrasonic wave, and fusing and joining the hub 9A with the substrate 4A. Next, the obtained two resin substrates with hub are laminated so that the center axes of the hubs 9A, 9B of the resin substrates 4A, 4B can be set coaxially by confronting the recording layers 3A, 3B, and the substrates 4A, 4B are joined with each other with or without interposing an inside ring shape spacer 5 and an outside ring shape spacer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for manufacturing an information recording medium in which a hub having a magnetically sensitive material is bonded to both sides.

[Technical Background of the Invention] In recent years, information recording media using high energy density beams such as laser beams have been developed and put into practical use. This information recording medium is called an optical disk, and is
It can be used as a disc, an audio disc, a large capacity still image file, and a large capacity computer disk memory.

An optical disc has a basic structure including a disc-shaped transparent resin substrate and a recording layer provided thereon. The surface of the substrate on which the recording layer is provided is coated with an undercoat layer or an intermediate layer made of a polymer material in order to improve the flatness of the substrate, improve the adhesion with the recording layer, and improve the sensitivity of the optical disc. may be provided.

Writing to or reading from the optical disc is performed by irradiating the recording layer of the optical disc with a laser beam while rotating the optical disc using a recording or reproducing device. Currently the diameter is 130mm (5.25 inches)
Regarding optical discs, an optical information recording medium using a hub (magnetic hub) is defined by the ISO standard.This optical disc consists of two disc-shaped discs with a circular hole in the center and a recording layer on at least one This is an information recording disk with an air sandwich structure in which two resin substrates are bonded with the recording layer inside, and a hub is bonded to both sides of the disk.The hub rotates the optical disk with a recording and reproducing device, etc. It plays a role as a disk clamp to ensure that the optical disk is securely mounted and fixed.It has a clamping hole in the center and is equipped with a magnetically sensitive material such as a metal piece, and the magnetic force causes the optical disk to be held in place. fixed to the device.

Therefore, when manufacturing an optical disk, the hub must be joined so that its center of rotation closely matches the center of rotation of the groove formed on the disk substrate. According to the ISO standard, the eccentricity is specified to be within 25 μm.

As mentioned above, as a method of joining the hub to the disc,
Broadly speaking, (A) a method in which a hub is fitted and joined using a circular hole provided in the center of a disk substrate so that its center is concentric with the center of rotation of the groove, and (B) a method in which a hub is fitted and joined using a circular hole provided in the center of a disk substrate so that its center is concentric with the center of rotation of the groove. There is a method of joining the hub using an XY table using the groove area boundary as a reference so that the center of the hub coincides with the rotation center of the groove.

Method (A) above allows the hubs to be joined together relatively easily, but it is important to ensure that the circular hole in the disk substrate is not eccentric to the center of rotation of the groove and that the diameter of the circular hole is accurate. must be manufactured. In addition, although method (B) above requires a special device to determine the rotation center of the groove, it is possible to accurately locate the rotation center of the groove without being affected by the eccentricity and diameter of the circular hole in the disk substrate. An advantage is that the hubs can be joined so that their centers coincide.

Japanese Patent Laid-Open No. 63-76131 proposes a disk hub mounting device for an optical disk that utilizes the method belonging to the above (B).

However, the device described in the above publication has several problems when put into practical use. One of them is means for detecting the boundary between the region of the disk substrate where the pregroove is formed and the region where the pregroove is not formed.

That is, in the apparatus described in the above publication, the reflectance detectors 202a and 202 shown in FIG.
b, 202c, and 202d are used to detect the boundary, but in reality, the center of rotation of the pregroove must be eccentric within 10 μm. The distance from the center to each reflectance detector, or the distance from the center to 202a = the distance from the center to 202b, and the distance from the center to 202a
The distance to 020=distance from the center to 202d, and each reflectance detector must be arranged so that the error thereof is highly accurate within 2 to 3 μm.

However, it is difficult to arrange each reflectance detector with such high precision and maintain it without being affected by changes in environmental conditions.

Further, when using the apparatus described in the above-mentioned publication, it is extremely difficult to precisely join the hub to the disk substrate using the ultrasonic fusion bonding method. The ultrasonic fusion bonding method is excellent for mass production because the bonding between the disk substrate and the hub is completed in an instant, and maintenance of the bonding equipment is easy because no liquid adhesive is used. This is an extremely excellent method for bonding a hub to a disk substrate, as it has many advantages, such as the fact that there is no adhesive as a foreign substance on the bonding surface, so the performance of the optical disk is less affected by changes in temperature and humidity. It is. However, it is practically undesirable that the ultrasonic fusion bonding method is difficult to use when the apparatus described in the above publication is used. Incidentally, the above-mentioned publication only describes a method of fixing the hub using an adhesive as a means of joining the hub.

The reason why it is extremely difficult to accurately join the hub to the disk substrate by the ultrasonic fusion bonding method when using the apparatus described in the above publication is as follows. That is,
The principle of ultrasonic welding is to convert ultrasonic electrical energy into mechanical vibration energy and apply pressure at the same time to generate frictional heat on the joint surface of the disk substrate and hub, melting and welding the joint surface. be. Therefore, since the horn of the ultrasonic welding machine vibrates during welding, the nodal point (the point of the smallest amplitude) of the horn is normally held elastically using an O-ring or the like.

Therefore, it is extremely difficult to join the hub temporarily fixed to the tip of such a horn in a state where it is stably and accurately centered with respect to the rotation center of the groove.

As a method of attaching a hub to an information recording medium in which two disc-shaped resin substrates each having a recording layer as described above are bonded with the recording layer inside, there is, for example, the method of attaching a hub to the information recording medium described in Utility Model Application Publication No. 63-1.
There is a method disclosed in Japanese Patent No. 42071. In this method, first, an opening in an information recording disk formed by joining two disk-shaped substrates via an annular spacer is opened in accordance with U.S. Patent Publication No. 63-1.
To install the hub in the four proposals in No. 42071, insert it into the head of the jig, place it on the flat part of the support base, and fit the center hole of the disc-shaped hub into the shaft that extends upward from the L surface of the head. The hub is then placed on the upper surface of the information recording disk and fixed with adhesive to produce a semi-finished product in which the hub is bonded to one side of the information recording disk. Next, remove this semi-finished product from the jig, turn the semi-finished product upside down, place it on the jig again, and do the same as above, fitting the center hole of the disk-shaped hub into the shaft part marked 2 and inserting the hub into the The hub is placed on the upper surface of the recording disk and fixed with an adhesive to produce an information recording medium in which hubs are bonded to both sides of the information recording disk.

However, the method disclosed in Japanese Utility Model Application Publication No. 63-142071 has the following drawbacks: ■ Since the hub is attached to the second surface based on the hub attached to the first surface, the accuracy of hub attachment on the second surface is low. Inferior to the hub installation accuracy on the first side,■
Although the above publication states that hubs can be fixed on both sides of the information recording disk using the same jig, in practice this is difficult in terms of attaching and detaching the workpiece and maintaining flatness. It is difficult to attach the hub accurately and efficiently to both sides of the hub.

Furthermore, in the above method, hubs are attached to both sides of the two information recording disks after they are pasted together, so if the granularity of the hub bonding to the disk on either side is poor and it is out of specification, There is also the problem that even if the hub is joined to the disk on the opposite side within the specifications, it cannot be used as an information recording disk product and is wasted.

[Object of the Invention] An object of the present invention is to provide a method for manufacturing a double-sided information recording medium with a hub having a large size and grain size with high productivity.

[Summary of the Invention] The present invention provides a disk-shaped resin substrate having a circular hole in the center and a recording layer on one side, and a magnetically sensitive layer on the inner circumference of the surface on which the recording layer is not provided. A first step of manufacturing a resin substrate with a hub by joining a disk-shaped magnetically sensitive hub with a clamping hole in the center, and two resin substrates with a hub manufactured in the first step, The recording layers are placed facing each other so that the central axes of the hubs of both resin substrates are coaxial, and an inner ring-shaped spacer and an outer ring-shaped spacer are placed between the two resin substrates at the inner and outer edges of the resin substrates, respectively. This method of manufacturing an information recording medium is characterized in that it comprises a second step of joining with or without intervening a ring-shaped spacer.

Preferred embodiments of the method 7 for producing an information recording medium of the present invention are as follows.

(1) The first step includes at least a disk support stand,
A disk locking part arranged to be located in the center of the disk support base, and a disk locking part protruding upward from the center of the upper surface of the disk locking part, the center axis of which is coaxial with the center axis of the disk locking part. (consisting of a hub locking part provided so as to)
Using the hub joining device, insert the circular hole of the resin substrate into the disk locking portion of the device, and fit the clamping hole of the hub into the hub locking portion of the device. and the step of manufacturing a resin substrate with a hub by joining the resin substrate and the hub so that the central axis of the circular hole and the central axis of the clamping hole are coaxial. A method for manufacturing the above information recording medium.

(2) In the first step, a vacuum groove is provided on the outer periphery for adsorbing the inner periphery of the disk substrate, and a hub locking protrusion is provided on the center for fitting the clamping hole of the hub.
A disk rotating means is provided rotatably on a spindle case fixed to a base with a spindle main shaft vertically having a disk substrate mounting member at the upper end, and a vacuum groove for adsorbing the outer circumference of the disk substrate. A disk eccentricity correction means movable in the horizontal and vertical directions, which surrounds the disk rotation means and is provided at the upper end; a means for detecting a groove or a groove region boundary formed in the disk substrate; and a hub by ultrasonic welding. Using a hub joining device equipped with at least a joining means, the resin substrate is suctioned and fixed to the disk rotating means, the hub is fitted into the hub locking protrusion and placed on the resin substrate, and the hub is placed on the resin substrate. The method is characterized by a step of detecting grooves or groove area boundaries formed in a resin substrate, correcting the eccentricity of the resin substrate, and bonding the resin substrate and the hub to produce a resin substrate with a hub. A method for manufacturing the above information recording medium.

(3) The method for manufacturing the information recording medium, characterized in that the hub is joined to the substrate by an ultrasonic fusion method.

(4) After the first step, an inspection step is provided to inspect the hub-equipped resin substrate manufactured in the first step, and only passed products are joined in the second step. .

(5) In the method for manufacturing an information recording medium according to E (1),
A method for manufacturing an information recording medium, characterized in that the eccentricity between the circular hole of the resin substrate and the pregroove on the surface of the resin substrate is 10 μm or less.

(6) The eccentricity between the central axis of the disk locking portion of the device used in the first step of the method for manufacturing an information recording medium of (1) above and the center axis of the hub locking portion is 2 μm or less, and the resin The gap between the circular hole of the board and the disk locking part is 5μ.
m or less, and the gap between the clamping hole of the slit hub and the hub locking portion is 8 μm or less.

In the description of this specification, "the central axis of the circular hole" means an axis that passes through the center of the circular hole and is perpendicular to the plane of the resin substrate. In addition, "the central axis of the clamping hole" means an axis that passes through the center of the clamping hole and is perpendicular to the plane of the hub.

DETAILED DESCRIPTION OF THE INVENTION Representative embodiments of the invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a partially sectional perspective view showing an example of an information recording medium manufactured according to an embodiment of the present invention.

In FIG. 1, the information recording medium 1 has a circular hole 2A in the center.
and a disk-shaped resin substrate 4A having a recording layer 3A on one surface, and a disk-shaped resin substrate 4B having a circular hole 2B in the center and having a recording layer 3B on one surface. but,
The resin substrate 4A is placed so that the recording layer 3A and the recording layer 3B face each other.
An inner ring-shaped spacer 5 is interposed between the inner periphery of the resin substrate 4A and the inner periphery of the resin substrate 4B, and an outer ring-shaped spacer 6 is interposed between the outer periphery of the resin substrate 4A and the outer periphery of the resin substrate 4B. It is constructed by being joined to.

A disk-shaped hub 9A having a magnetically sensitive body 7A and a clamping hole 8A in the center is bonded to the inner circumference of the surface of the resin substrate 4A where the recording layer 3A is not provided. A disc-shaped hub 9B, which has a magnetically sensitive material (not shown) like the hub 9A and has a clamping hole 8B in the center, is bonded to the inner periphery of the surface where the recording layer 3B is not provided. ing. The central axis of the circular hole 2A and the central axis of the clamping hole 8A are joined to be coaxial, and the central axis of the circular hole 2B and the central axis of the clamping hole 8B are joined to be coaxial. The central axis of the clamping hole 8A and the central axis of the clamping hole 8B are also joined to be coaxial.

The diameter of the resin substrates 4A, 4B is approximately 130 mm, and the diameter of the circular holes 2A, 2B is approximately 15 mm.

The resin substrates 4A and 4B are made of a material arbitrarily selected from various materials conventionally used as substrates for information recording media. Optical properties of the substrate, flatness,
In terms of processability, handling, stability over time, and manufacturing cost, examples of substrate materials include acrylic resins such as cell cast polymethyl methacrylate, injection molded polymethyl methacrylate, and polymethyl acrylate; polyvinyl chloride, and chloride. Vinyl chloride resins such as vinyl copolymers;
Preferred examples include epoxy citrus: amorphous polyolefin resin; and synthetic resins such as polycarbonate. Among these, preferred are polymethyl methacrylate, polycarbonate, and epoxy resin from the viewpoint of dimensional stability, transparency, heptahedrality, and the like.

An undercoat layer (and/or intermediate layer) is provided on the surface of the substrate on which the recording layers 3A and 3B are provided for the purpose of improving flatness, increasing adhesive strength, and preventing deformation 1 of the recording layer. You can leave it there.

Examples of materials used for the recording layers 3A and 3B include Te.
, Zn, In, Sn, Zr, A11. , Ti, Cu, G
Examples include metals such as e, Au, and Pt; metalloids such as B11As and Sb; semiconductors such as Si; and alloys thereof, or combinations thereof. In addition, these metals,
Compounds such as metalloid or semiconductor sulfides, oxides, borides, silicon compounds, carbides and nitrides: and mixtures of these compounds with metals can also be used in the recording layer. Alternatively, dyes, combinations of dyes, polymeric dyes, and the aforementioned metals and metalloids may be utilized.

The recording layers 3A and 3B may further contain various known metals, semimetals, or compounds thereof as recording layer materials.

The recording layers 3A and 3B can be formed on the substrate directly or via an undercoat layer by using the above-mentioned materials by methods such as vapor deposition, slatting, ion blating, and coating.

The hubs 9A, 9B are disk-shaped having the magnetically sensitive bodies 7A, 7B and the clamping holes 8A, 8B in the center as described above, and are also called magnetically sensitive hubs, and have bosses. It's something you don't do.

The material of the hubs 9A and 9B is not particularly limited as long as it can be bonded well to the disc-shaped substrate, and examples include polycarbonate resin,
Mention may be made of thermoplastic resins such as polyacrylic resins and acetal resins.

Further, it is preferable that the hubs 9A and 9B be made of the same material as the disc-shaped substrate in consideration of the coefficient of thermal expansion and the tensile coefficient of the moisture absorbing portion.

The magnetically sensitive bodies 7A and 7B are made of a magnetically sensitive material such as iron or an alloy containing iron, but are preferably made of a rust-resistant material. The form of the magnetically sensitive bodies 7A, 7B is not particularly limited), but typical forms include a magnetically sensitive piece in the shape of a rod, plate, ring, etc., joined to the hub body, Alternatively, the entire knob can be made magnetically sensitive by kneading magnetically sensitive powder into the material of the hub and injection molding it.

One of the preferred embodiments of manufacturing a hub-equipped resin substrate in the first step of the present invention includes at least a disk support, a disk locking portion located at the center of the disk support, and Using a hub joining device consisting of a hub locking part that projects upward from the center of the upper surface of the disk locking part and is provided so that its center axis is coaxial with the center axis of the disk locking part, Insert the circular hole of the resin substrate into the disk engaging portion of the device, fit the clamping hole of the hub into the hub engaging portion of the device, and align the central axis of the circular hole with the central axis of the clamping hole. This is a method of manufacturing a resin substrate with a knob by joining the resin substrate and the hub so that they are coaxial. Hereinafter, this aspect will be referred to as aspect A.

In aspect A, as will be described in detail below, when joining the hub to the circular hole of the resin substrate, the hub is positioned based on the circular hole of the resin substrate. Rather than having a loose precision in which the position is approximately at the center/edge 1, the circular hole is placed at the center of the resin substrate so that there is almost no eccentricity between the circular hole in the resin substrate and the pregroove on the resin gripping surface. It is necessary to provide it accurately (that is, so that the circular hole and the pregroove are concentric). Such a resin substrate can be obtained by molding the resin substrate having the circular hole more strictly and accurately than is normally done. Preferably, the eccentricity between the circular hole and the pregroove on the surface of the resin substrate is 104 m or less. Particularly preferably, it is within 7 μm.

FIG. 2 is a partial sectional view illustrating an embodiment of aspect A of the first step of the present invention together with a hub joining device used in a method for manufacturing the information recording medium shown in FIG. 1.

In FIG. 2, the hub joining device 20 includes a disk support 22 having a disk locking portion 21 in the center thereof, and an ultrasonic welding machine 25. Disc locking part 21
is a disc-shaped protrusion that is shaped so that the circular hole 2A of the resin substrate 4A fits precisely, and a hub locking shape that allows the ramping hole 8A of the hub 9A to fit precisely into the center of the disk locking part 21. A portion 23 is integrally provided in a protruding manner. The center axis of the disk locking portion 21 (a straight line passing through the center of the circle of the disk locking portion 21 and perpendicular to the disk support surface 22a of the disk support base 22) and the center axis of the hub locking portion 23 are coaxial. It is formed to be. Further, when the resin substrate 4A is placed on the disk support surface 22a, a recess 24 is provided in the disk support surface 22a facing the recording layer 3A, so that the recording layer 3A does not come into contact with the disk support base 22. ing. The ultrasonic fusion splicer 25 is equipped with an application horn 26 for applying ultrasonic waves, and the ultrasonic waves are transmitted to the ultrasonic oscillator 2.
7 and passes through the converter 28 to the application horn 26
It is intended to be transmitted to

It is preferable that the eccentricity between the center axis of the disk locking part 21 and the center axis of the hub locking part 23 be 2 μm or less, particularly 1 μm or less.

Also, the gap between the circular hole 2A and the disc locking part 21 is 5 μm.
m or less, especially 3 μm or less, and the clamping hole 8
The gap between A and the hub locking part 23 is 8 μm or less, especially 5 μm.
Preferably, it is manufactured as follows.

Next, a method of joining the hub 9A to the inner peripheral portion of the resin substrate 4A using the hub joining device 20 will be described.

First, the resin substrate 4A is placed on the disk support surface 22a by inserting the circular hole 2A into the disk locking portion 21 with the recording layer 3A facing downward.

Next, the hub 9A is placed on the resin substrate 4A by inserting the clamping hole 8A into the hub locking portion 23 with the magnetically sensitive body 7A facing upward. An energy director IOA for ultrasonic fusion is provided on the lower surface of the hub 9A.

Next, the application horn 26 of the ultrasonic fusion splicer 20 is lowered to press the hub 9A, and ultrasonic waves are applied from the application horn 26 to fusion-bond the hub 9A to the resin substrate 4A to form a hub-attached resin substrate. Manufacture.

Since the disk locking portion 21, the hub locking portion 23, and the relative relationship thereof of the hub joining device 20 are manufactured as described above, the resin substrate with the hub manufactured by the method described above is made of resin. The pregroove on the substrate surface and the hub are joined with extremely small eccentricity.

The hub 9A and the resin substrate 4A may be joined together by other heat fusion methods or α-
Adhesion may be performed using a cyanoacrylate adhesive, a synthetic rubber adhesive, an epoxy adhesive, an ultraviolet curable adhesive, a urethane adhesive, or another adhesive.

FIG. 3 shows another embodiment of aspect A of the first step of the present invention,
FIG. 2 is a partial sectional view illustrating a method for manufacturing the information recording medium shown in FIG. 1 together with a hub joining device to be used.

In FIG. 3, the hub joining device 30 has a cylindrical positioning shaft 31 therein so as to be able to move linearly in the vertical direction (when the positioning shaft 31 is pushed down and the force is released, the position is in the upper position). a cylindrical disk support 32 supported by a spring 33 so that it can be restored to
It consists of an ultrasonic fusion machine 40.

The upper surface of the disk support stand 32 is formed into a flat surface, and the disk support surface 34 is an annular ring-shaped disk support surface 34 having a hole in the center into which the positioning shaft 31 can be inserted. Vacuum groove 35 opened in
A vacuum hole 36 is provided at the other end of the vacuum hose 3.
7 to a vacuum pump (not shown).

The diameter of the cross section of the positioning shaft 31 is larger than the diameter of the circular hole 2A of the resin substrate 4A.
The upper end portion thereof forms a disk locking portion 38 in the shape of a truncated cone that gradually tapers upward and the diameter of the upper end surface is smaller than the diameter of the circular hole 2A of the resin substrate 4A.

A hub locking portion 39 protruding from the center of the disk locking portion 38 is provided in a shape that allows the clamping hole 8A of the hub 9A to precisely fit therein. The center axis of the disk locking portion 38 and the center axis of the hub locking portion 39 are formed to be coaxial with the ring center of the positioning shaft 31.

The ultrasonic fusion splicer 40 is equipped with an application horn 41 for applying ultrasonic waves, and ultrasonic waves are oscillated from an ultrasonic oscillator 42.
The signal is transmitted to the application horn 41 via the converter 43.

In FIG. 3, the resin substrate 4A is attached to the disk support surface 34.
Although a vacuum adsorption device is shown as a means for fixing the material to the surface, mechanical fixing means or magnetic fixing means may be used instead.

The eccentricity between the central axis of the disk locking part 38 and the center axis of the hub locking part 39 and the gap between the clamping hole 8A and the hub locking part 39 are the same as described with reference to FIG.

Next, a method of joining the hub 9A to the inner peripheral portion of the resin substrate 4A using the hub joining device 30 will be described.

First, the resin substrate 4A is placed on the disk support surface 34 by inserting the circular hole 2A into the disk locking portion 38 with the recording layer 3A facing downward. When the resin substrate 4A is attracted to the disk support surface 34 by suction from the vacuum groove 35, an upward force is applied to the positioning shaft 31 due to the elastic force of the spring 33, and the shape of the disk locking portion 38 is as described above. Therefore, the resin substrate 4A moves downward toward the disk support surface 34 and at the same time moves horizontally as well, and when the resin substrate 4A is in contact with the disk support surface 34, The central axis of the circular hole 2A comes to completely coincide with the central axis of the disk locking portion 38.

Next, the hub 9A is placed on the resin substrate 4A by inserting the clamping hole 8A into the hub locking portion 39 with the magnetically sensitive body 7A facing upward. An energy director IOA for ultrasonic fusion is provided on the lower surface of the hub 9A.

Next, the application horn 41 of the ultrasonic fusion splicer 40 is lowered to press the hub 9A, and ultrasonic waves are applied from the application horn 41 to fusion-bond the hub 9A to the resin substrate 4A to form a hub-attached resin substrate. Manufacture.

Since the disk locking portion 38, the hub locking portion 39, and the relative relationship thereof of the hub joining device 30 are manufactured as described above, the resin substrate with the hub manufactured by the method described above is made of resin. The pregroove on the substrate surface and the hub are joined with extremely small eccentricity.

The method for joining the hub 9A and the resin substrate 4A may be, in addition to the above-mentioned ultrasonic welding method, another heat welding method, a bonding method using an adhesive, or the like.

Another preferred embodiment of manufacturing a hub-equipped resin substrate in the first step of the present invention is to provide a vacuum groove on the outer periphery for adsorbing the inner periphery of the disk substrate, and fit the clamping hole of the hub into the outer periphery. a disk rotating means, which is rotatably provided on a spindle case fixed to a base, with a spindle main axis vertically provided at the upper end of the disk substrate mounting surface, each having a hub locking protrusion at the center thereof; A horizontally and vertically movable disk eccentricity correcting means having a vacuum groove surrounding the disk rotating means at the upper end for adsorbing the outer circumferential portion of the disk substrate, and a groove or a groove formed in the disk substrate. Using a hub joining device that is equipped with at least means for detecting a region boundary and means for joining hubs by ultrasonic welding, the resin substrate is adsorbed and fixed to the disk rotating means, and the hub is attached to the hub. The hub is fitted onto the stop protrusion and placed on the resin substrate, and the eccentricity of the resin substrate is corrected by detecting the groove or groove area boundary formed on the resin substrate, and the resin substrate and the hub are bonded. This is a method of manufacturing a resin substrate with a hub. Hereinafter, this aspect will be referred to as aspect B. When joining the hub to the resin substrate according to aspect B, the resin substrate does not need to be precisely provided so that the circular hole is not eccentric to the groove, and the circular hole or approximately the center of the resin substrate is not required. It may be provided so as to be located at.

FIG. 4 is a partially cross-sectional schematic diagram showing an embodiment of a hub joining device used to manufacture a hub-equipped resin disk substrate according to aspect B of the first step of the present invention.

In FIG. 4, the hub joining device includes a disk rotating means fixed to the base 100, a disk eccentricity correcting means fixed to the base 100, and an upper part of the outer periphery of the disk placed on the disk rotor stage. It is composed of a groove region boundary detection means 300 and an ultrasonic fusion bonding means 400 disposed above the central portion of the disk rotation means.

The disk rotation means is provided with a spindle main shaft 1.degree. 2 vertically arranged so as to be rotatable in a spindle case 101 fixed to a base 1oo.
A disk substrate mounting section 104 having a disk substrate mounting surface 103 on the upper surface is provided on the top of the disk substrate mounting section 104, and a hub for fitting the clamping hole of the hub 9A is provided at the center of the upper surface of the disk substrate mounting section 104. A locking protrusion 105 is provided so as to protrude from the disk substrate mounting surface 103 and be concentric with the spindle main shaft 102.
A vacuum groove 106 is provided on the outer periphery of the upper surface of 04 to attract the inner periphery of the disk substrate 4A, and a timing pulley 107 is attached to the lower part of the spindle main shaft 102. It is configured to be rotated. The vacuum groove 106 communicates with a long hole E0 provided in fPJb of the main spindle rP4102, and is connected to a vacuum pump (not shown) via a rotary joint 111 and a hose 112 attached to the lower end of the spindle main shaft 102. It is designed to be attracted by. Spindle main III110
2 needs to be attached to the spindle case 101 with high rigidity to prevent axial movement and lateral wobbling, and for that purpose, it is preferable to attach it using an angular bearing, for example. The outer diameter of the tip of the hub locking protrusion 105 is substantially the same as the diameter of the clamping hole of the hub 9A (4 mm for a 5.25 inch optical disc).
- method, and the clearance is preferably within 0.006 mm. The motor 109 is preferably a stepping motor because its speed can be easily controlled and the rotation angle can be easily specified.

The disk eccentricity correction means is a known XYZ table (XYZ stage). That is, the disk eccentricity correction means is a Z-direction fine movement mechanism 20 fixed to the base 100.
Z table 2 supported vertically movably by 1
02, an X-direction fine movement mechanism 203 is fixed, and an X-table 204 is provided so as to be movable in the left and right horizontal directions in FIG.
A Y-direction fine movement mechanism (not shown) is fixed thereon, and a Y-table 205 is further provided so as to be movable in horizontal directions on the front and back sides of the paper in FIG. The Z table 202, the X table 2°4, and the Y table 205 are
It has a donut-like structure surrounding the disk rotating means. A vacuum groove 20 is provided on the upper surface 206 of the Y table 205 for sucking the outer peripheral portion of the disk substrate 4A.
7 is provided and is adapted to be suctioned through a hose 208 by a vacuum pump (not shown). The strokes of the Z table 202, X table 204 and Y table 205 are each ±1 for a 5.25 inch disc.
It only needs to be about mm, and the resolution is X table 204 and Y
About 1 μm for table 205, Z table 202
It is sufficient if the thickness is approximately 10 μm. Also, Z table 2
According to 02, one surface 2°6 of the Y table 205 is the same as the disk substrate mounting surface 103 - water! Y position (“same” position), higher than the disk substrate mounting surface 1°3 (“high J position”), and lower than the disk substrate mounting surface 103 (
It is set so that three positions can be selected: ``low position''.For a 5.25 inch disk, the ``high'' position is such that the upper surface 206 is approximately 1 mm lower than the disk mounting position 103. The "low" position is approximately 1 mm lower than the upper surface 206 or the disk substrate mounting surface 103.

Groove area boundary detection means 300 detects the disc substrate 4A.
This is a means for detecting a boundary 12A between a groove area IIA formed on the surface of the groove and a portion where no groove is formed. As a method for detecting the center of rotation of a groove, since the light reflectance is different between the groove area and the part where no groove is formed, there is a method of detecting the boundary by measuring the reflectance of both in this way. There is also a method of detecting any single track in the groove area (even if the tracks are formed in a spiral shape, the track pitch is extremely small, so the tracks can be considered as concentric circles). In the present invention, either method may be adopted; in the case of the former method, a microscope, line sensor, CCD camera, etc. can be used as the groove region boundary detection means 300; In some cases, optical pickups and the like can be used.

In FIG. 4, a combination of a microscope, a CCD camera, a CRT display, and a storage device is used as the groove region boundary detection means 300.

As the ultrasonic fusion bonding means 400, those generally available on the market can be used. For example, an ultrasonic fusing machine can be used in which ultrasonic waves are emitted from an ultrasonic transmitter 401 and transmitted through a converter 402 to an application horn 403. It has an application horn 403 with a tip shape as shown in FIG. 4, and is not of the type in which the hub 9A is attached in advance.

Next, a method for joining a hub to a disk substrate using the hub joining apparatus shown in FIG. 4 will be described.

(+) The two-direction fine movement mechanism 201 brings the Z table 202 to the “low” position. Place the disk substrate 4A on the disk substrate mounting surface 103 as shown in FIG.
06 to suction and fix the disk substrate 4A to the disk substrate mounting surface 103. The hub 9A is placed on the disk board 4A. As shown in a perspective view in FIG. 5, the hub 9A has a substantially annular shape, and has a clamping hole 8 in the center.
A is formed, a ring-shaped energy director IOA is formed on the outer periphery, and a magnetically sensitive material (not shown) is formed on the opposite surface.
is installed. The hub 9A is placed on the disk substrate 4Ah with the energy director IOA facing down and the clamping hole 8A fitted into the hub locking protrusion 105.

(2) Next, the groove area detection means 300 detects and stores the position of the boundary 12A of the groove area 11A. The position of the boundary 12A at this time is defined as a boundary position (Po) in the 0° direction. Next, the motor 109 is activated to rotate the spindle main shaft 102 by 90 degrees, and the boundary 1 at that time is
Detect and store the position of 2A. Boundary 12 at this time
Let the position A be the boundary position (P 90) in the 90'' direction.

Thereafter, in the same manner, the spindle main shaft 102 is rotated by 90", the position of the boundary 12A is detected each time, and the position is 180°.
The boundary position in the direction (P+ao) and the boundary position in the 270'' direction (P270) are determined. In this way, the boundary positions in the four directions are determined.

FIG. 6 shows a projection of these boundary positions on a CRT display. In Fig. 6, half of the difference (DX) between Po and PI30 is taken as the amount of eccentricity in the X direction δ8, and P9
Let half of the difference (DY) between ° and p2ta be the eccentricity δ7 in the Y direction.

(3) Next, the Z table 202 is brought to the "same" position by the Z direction fine movement mechanism 201. The disk substrate 4A is suctioned from the vacuum groove 207 onto the upper surface 20 of the Y table 205.
6 and fix it by suction. Next, suction from the vacuum groove 106 is stopped, and the disk substrate 4A is made free with respect to the disk substrate mounting surface 103.

(4) Next, the Z table 202 is set to the “high” position by the Z direction fine movement mechanism 201, and the X direction fine movement mechanism 203
is operated to move the X table 204 by the eccentricity δ8 obtained in (2) above in the direction in which the eccentricity becomes zero, and the Y-direction fine movement mechanism is operated to move the Y table 205 to the above (2).
) is moved in the direction in which the eccentricity becomes zero by the eccentricity δ7 found in ().

(5) Next, the Z table 202 is brought to the "same" position by the Z direction fine movement mechanism 201, and suction is also applied from the vacuum groove 106 to suction and fix the disk substrate 4A to the disk substrate mounting surface 103.

(6) Next, operate the ultrasonic fusion bonding means 400,
The hub 9A is fused and bonded to the disk substrate 4A by a conventional method. At this time, the energy director 10A melts and disappears, and the two are firmly joined.

(7) Release the suction by the vacuum grooves 106 and 207 and take out the disk substrate to which the hub is bonded.

Through the above steps, it is possible to manufacture a disk substrate in which a hub is bonded to one side of the disk substrate in a state where the hub is accurately centered on the rotation center of the groove of the disk substrate.

In the second step of the present invention for manufacturing the information recording medium shown in FIG.
) are stacked together with the recording layers facing each other so that the center axes of the hubs of both resin substrates are coaxial, and an inner ring-shaped spacer and an outer ring are placed between the two resin substrates The shaped spacers are interposed and bonded to the inner and outer peripheral edges of the resin substrate, respectively.

The resin substrate 4B to which the hub 9B shown in FIG. 1 is bonded can be manufactured in exactly the same manner as the resin substrate 4A to which the hub 9A is bonded.

For example, a method for manufacturing an air sandwich type information recording medium from two resin substrates to which a hub is not bonded, an inner ring-shaped spacer, and an outer ring-shaped spacer is as follows.
JP-A-62-267939, JP-A-61-80535
In the second step of the present invention,
Information as shown in FIG. 1 was obtained by carrying out the procedure in the same manner as the known method except for using the two resin substrates with hubs manufactured as described above in place of the two resin substrates to which no hubs were bonded. Recording media can be manufactured.

Information recording media that can be manufactured according to the present invention also include so-called magneto-optical disks in which a recording layer made of a magnetic layer is formed. In this case, in the second step, the information recording medium is manufactured by bonding the recording surfaces of the two resin substrates together with a suitable adhesive without using a ring-shaped spacer. Bonding the recording surfaces of two resin substrates to each other with a suitable adhesive is also known for resin substrates to which hubs are not bonded. Instead of two resin substrates, a hub with a hub manufactured as described above was used.
The information recording medium can be manufactured in the same manner as a known method except that two resin substrates are used.

In the second step of the present invention, the eccentricity (misalignment) between the two resin substrates is preferably 50 μm or less, particularly 30 μm or less.

In the present invention, an inspection step is provided between the first step and the second step to inspect the quality of the hub-attached resin substrate manufactured in the first step, such as the joining accuracy of the hub and the presence or absence of scratches on the resin substrate,
It is preferable to join only the accepted products among the resin substrates with hubs manufactured in the first step in the second step.

Below are the margins [Effects of the Invention (1) Quality Effects The method for manufacturing an information recording medium of the present invention manufactures information recording media with small eccentricity, especially resin substrates with hubs on the A side and B side, by the same method. Since it is a method, it has a remarkable effect that it is possible to manufacture a high information recording medium with the same precision on the A side and the B side.

Furthermore, when joining a hub to a resin substrate by ultrasonic fusion, in the manufacturing method of the present invention, the resin substrate is only subjected to ultrasonic waves once (two resin substrates are bonded together). When joining hubs to both sides of the assembly, -
A sheet of resin substrate will be subjected to ultrasonic waves at least twice, which may reduce the mechanical properties of the resin substrate, especially the impact resistance strength), and minimize changes in the physical properties of the resin substrate due to ultrasonic application. can be done.

(2) Effect on product yield The present invention consists of a first process of bonding the hub to the resin substrate and a second process of bonding the hub-attached resin substrate, so the hub bonding accuracy falls within the allowable range. Since only the parts need to be joined in the second process, waste in the second process is reduced and the yield of the final product is increased.

(3) Effects on manufacturing equipment When joining a hub after pasting two resin boards together, the equipment used to join the hub first and the equipment used later to connect the resin board with the hub joined to one side. It is necessary to use a different device for joining the hub, but in the present invention, the hub can be joined to one side of a single resin substrate, so only one type of hub joining device is required. .

When the hub is bonded using a UV curing resin, UV irradiation efficiency is better when the hub is bonded to one resin substrate than when the hub is bonded to two resin substrates bonded together.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view showing an example of an information recording medium manufactured according to an embodiment of the present invention. FIG. 2 is a partial sectional view illustrating an embodiment of aspect A of the first step of the present invention together with a hub joining device used in a method for manufacturing the information recording medium shown in FIG. 1. FIG. 3 shows another embodiment of aspect A of the first step of the present invention,
FIG. 2 is a partial sectional view illustrating a method for manufacturing the information recording medium shown in FIG. 1 together with a hub joining device to be used. FIG. 4 is a partially cross-sectional schematic diagram showing an embodiment of a hub joining device used for manufacturing a hub-equipped resin disk substrate according to aspect B of the first step of the present invention. FIG. 5 is a perspective view showing an example of the hub. FIG. 6 is a schematic diagram of the state in which the boundary position of the groove area of the disk substrate is detected and is displayed on a CRT display. 1: Information recording medium, 2A, 2B: Circular hole, 3A, 3B: Recording layer, 4A, 4B: Resin substrate, 5: Inner ring-shaped spacer, 6: Outer ring-shaped spacer, 7A, 7B: Magnetically sensitive material, 8A , 8B: Clamping hole, 9A, 9B = hub, 10A: energy director, 11A niger loop area, 12A: boundary, 20: hub joining device, 21: disc locking part, 22: disc support base, 23: hub holder stop part, 24: recess, 25 two ultrasonic fusion machines, 26: application horn, 27: ultrasonic oscillator, 28: converter, 30: hub joining device, 31: positioning shaft, 32: disk support stand, 33 Spring, 34: Disc support surface, 35: Vacuum groove, 36: Vacuum hole, 37: Vacuum hose, 38: Disc locking part, 39: Hub locking part, 40: Ultrasonic fusion machine, 41: Application horn, 42: Ultrasonic oscillator, 43: Converter. 100: Base, 101 Nissin spindle case, 102 Nissin spindle main shaft, 103: Disc substrate placement surface, 104: Disc substrate placement part, 105: Hub locking protrusion, 106: Vacuum groove, 107: Timing pulley 108: Timing belt , 109: Motor, 110: Long hole, 111: Rotary joint, 112: Hose, 113 Varnish spacer, 201: Z
Direction fine movement mechanism, 202: Z table, 203: X direction fine movement mechanism, 204: X table, 205: Y table, 206: Top surface, 207: Vacuum groove, 2o8: Hose, 300 Nigelpu region boundary detection means, 400: Ultrasonic fusion bonding means, 401: Ultrasonic transmitter, 402: Converter, 403: Application horn,

Claims (1)

[Claims] 1. A disc-shaped resin substrate with a circular hole in the center and a recording layer on one side has a magnetically sensitive material on the inner periphery of the side where the recording layer is not provided and is clamped at the center. A process of manufacturing a resin substrate with a hub by joining a disc-shaped magnetically sensitive hub having a hole so that the central axis of the circular hole and the central axis of the clamping hole are coaxial, the process comprising at least the following steps: a disk support stand, a disk locking part located at the center of the disk support stand, and a disk locking part that protrudes upward from the center of the upper surface of the disk locking part, with its central axis aligned with the center of the disk locking part. Using a hub joining device consisting of a hub locking portion provided coaxially with the shaft, the circular hole of the resin substrate is inserted into the disk locking portion of the device, and the clamp of the hub is inserted. a first step of manufacturing a resin substrate with a hub by fitting the pin hole into the hub locking portion of the device and joining the resin substrate and the hub; and a step of manufacturing a resin substrate with a hub manufactured in the first step. The two resin substrates are placed one on top of the other with the recording layers facing each other so that the center axes of the hubs of both resin substrates are coaxial, and an inner ring-shaped spacer and an outer ring-shaped spacer are respectively inserted between the two resin substrates inside the resin substrate. A method for manufacturing an information recording medium, comprising a second step of joining the peripheral edge and the outer peripheral edge with or without intervening a ring-shaped spacer. 2. A disc-shaped resin substrate with a circular hole in the center and a recording layer on one side has a magnetically sensitive material on the inner periphery of the side where the recording layer is not provided and is clamped at the center. A first step of manufacturing a hub-equipped resin substrate by joining disc-shaped magnetically sensitive hubs having holes; and a first step of manufacturing a hub-equipped resin substrate by joining two disk-shaped magnetically sensitive hubs with holes; The substrates are stacked so that the central axes of their hubs are coaxial, and an inner ring-shaped spacer and an outer ring-shaped spacer are interposed between the two resin substrates at the inner and outer edges of the resin substrate, respectively, or a ring-shaped spacer is placed between the two resin substrates. A method for manufacturing an information recording medium, comprising a second step of bonding without intervening. 3. The first step includes at least a disc support base, a disc locking part located at the center of the disc support base, and a disc locking part that protrudes upward from the center of the upper surface of the disc support base, Using a hub joining device consisting of a hub locking portion whose shaft is coaxial with the center axis of the disk locking portion, connect the circular hole of the resin substrate to the disk locking portion of the device. and fit the clamping hole of the hub into the hub locking part of the device, and align the resin substrate with the circular hole so that the center axis of the circular hole and the center axis of the clamping hole are coaxial. 3. The method for manufacturing an information recording medium according to claim 2, further comprising the step of manufacturing a resin substrate with a hub by joining the resin substrate with a hub. 4. The first step is to provide a vacuum groove on the outer periphery for adsorbing the inner periphery of the disk substrate and a hub locking protrusion on the center for fitting the clamping hole of the hub, and then place the disk substrate on the disk. A disk rotating means is provided rotatably on a spindle case fixed to a base, with a spindle main shaft having a vertical surface at the upper end, and a vacuum groove for adsorbing the outer periphery of the disk substrate is attached to the disk rotating means. A disk eccentricity correcting means which is movable in the horizontal and vertical directions and which surrounds the disk substrate and has the upper end thereof, a means for detecting a groove or a groove region boundary formed in the disk substrate, and a means for joining the hub by ultrasonic welding. Using at least a hub joining device, the resin substrate is adsorbed and fixed to the disk rotating means, the hub is fitted into the hub locking protrusion and placed on the resin substrate, and the resin substrate is formed. 2. The step of manufacturing a hub-equipped resin substrate by detecting grooves or groove area boundaries, correcting the eccentricity of the resin substrate, and joining the resin substrate and the hub. A method for manufacturing an information recording medium according to.