JPH0453014B2 - - Google Patents

Abstract

PURPOSE:To make the post-working of a hole unnecessary, even if there is a dispersion in the center hole diameter of a substrate, and to secure the position accuracy of the hole by forming an elastic center boss so that it is pressed lightly into one substrate center hole, and fitted softly into the other substrate center hole. CONSTITUTION:An external form of an elastic center boss 11 consists of a tapered thin wall structure. A disk substrate 2 having a recording layer 1 on it is pressed lightly into the base part of a boss 11 installed a rotary tool 6, a viscous adhesive agent 8 is applied, and when a protective substrate 9 which is fitted softly to the boss 11 is superposed, the adhesive agent spreads and goes into a center hole 12. Subsequently, when the substrate is rotated, the adhesive agent spreads toward the outside peripheral edge by a centrifugal force, and it is hardened by irradiating an ultraviolet ray. Accordingly, since the external form of the boss 11 has been tapered, even if a dispersion or a deformation is generated in the center hole diameter of the substrate, the adhesive agent is not protruded to the center hole part, the post-working of the hole in unnecessary, and the position accuracy of the hole can be secured.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an information carrier disk (hereinafter simply referred to as a disk) made by bonding two disk-shaped substrates including at least one disk-shaped substrate having an information medium layer.
The present invention relates to a manufacturing method.

Conventional technology Conventionally, a viscous adhesive is sandwiched between two disc-shaped substrates, and while the two substrates are rotated, the adhesive is uniformly filled over the entire surface between the two substrates to bond them together. Although there is no example in which this has been proposed, the prior invention by the present inventors had a configuration as shown in FIG. That is, a disk-shaped disk substrate 2 with a recording medium layer 1 formed on one side is mounted on a rotating tool 6 having a groove 3 for vacuum suction and a ventilation hole 4, and a shaft 5 on the center of rotation. After fixing via the center boss 7 and applying a viscous adhesive 8 concentrically with the center boss 7, the protective substrate 9 is stacked and the adhesive 8 is applied to the entire center boss 7 due to the weight of the protective substrate 9. After leaving the two substrates until they come into contact with the periphery, the two substrates are rotated to fill the entire surface of the substrates with adhesive 8, and the excess adhesive is shaken off to form an adhesive layer of uniform thickness. After curing, the bonding of the two substrates is completed.

Problems to be solved by the invention However, when the center boss 7 has a cylindrical shape,
If the diameter of the center hole 10 of the disk substrate 2 fluctuates due to production variations, or if it is deformed from a perfect circle to, for example, an elliptical shape, a gap will be created between the center boss 7 and the center hole 10. There was a problem in that the adhesive 8 overflowed from the gap and in extreme cases could wrap around the surface of the disk or adhere to the rotating tool 6. Furthermore, when the disk is completed, the adhesive 8 will adhere irregularly to the center hole 10, which is the center of rotation for recording and playback, and will harden. will be formed,
This impairs the positional accuracy of the center hole 10. For these reasons, attempts are made to improve the fitting precision of the center boss 7 to the center hole 10 of the disk substrate 2 as much as possible. was not very effective.

Furthermore, since the center boss 7 is cylindrical, there is also the problem that it is difficult to insert the protective substrate 9 when stacking them together.

The present invention prevents the adhesive 8 from overflowing into the center hole even if there are variations in the center hole diameter or deformation of the center hole, and at the same time prevents the adhesive 8 from overflowing into the center hole. The aim is to create a manufacturing method that does not require processing.

Means for Solving the Problems In order to solve the above problems, the sense boss that aligns the two substrates is made elastic and its outer shape is tapered.

In other words, by making the center boss into a tapered hollow thin-walled shape to give it elasticity, even if the center hole diameter of the disk substrate varies or is deformed from a perfect circle, the center boss will have elasticity. With a certain center boss, there is no possibility that the adhesive will protrude along the center hole of the disk substrate. Further, by tapering the outer shape, adhesive does not adhere to the edge of the center hole on the disk surface side, and the original positional accuracy of the center hole is not impaired. Furthermore, the tapered shape facilitates overlapping on the protective substrate.

As a result, even if there are variations in the center hole diameter or deformation of the perfect circle, it is possible to bond the center hole without the adhesive overflowing into the center hole, and the positioning accuracy of the center hole is not compromised, and post-processing of the center hole is not required. This makes it possible to perform bonding without having to do so.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

In FIG. 1, the center boss 11 has a hole in the center into which the shaft 5 of the rotary tool 6 is loosely fitted, has a tapered outer shape, has a thin wall structure, and has elasticity. The dimensions of this tapered part are such that the smaller diameter side is smaller than the center hole 10 of the disk substrate 2, and the larger diameter side is larger than the center hole 10.
The disk substrate 2 and the center boss 11 are attached to the rotating tool 6.
When installed, the center hole 10 of the disk board 2
The dimensions are such that it can be lightly press-fitted into the

Next, a method of bonding two disk-shaped substrates together using this center boss 11 will be explained with reference to FIGS. 1 to 3. First, insert the center boss 11 into the shaft 5 of the rotating tool 6 as shown in FIG. The disk substrate 2 is vacuum-suctioned through the groove 3 and the ventilation hole 4. The outer diameter of the center boss 11 corresponding to the position where the disk substrate 2 is vacuum-sucked is the center hole 1 of the disk substrate 2.
Since the hole diameter is slightly larger than the hole diameter of 0, vacuum suction is performed by lightly pressing the disk substrate 2. By applying light pressure and vacuum suction in this manner, one edge of the center hole 10 of the disk substrate 2 and the center boss 11 are lightly press-fitted. The rotary tool 6 is rotated around the shaft 5 while this vacuum suction is being performed, but this can be easily done by using a motor and a rotary joint (not shown) as is commonly done. It is something that can be done.

Next, apply ultraviolet polymerized adhesive 8 to the disk substrate 2.
is applied concentrically to the center hole 10, and the protective substrate 9 is brought into contact with the entire circumference of the adhesive 8 to prevent air bubbles from being mixed therein. If the protective substrate 9 is left to stand naturally in this state, the adhesive 8 will not cause air bubbles to be trapped in the directions of the inner and outer circumferences of the disc-shaped substrate, as shown in FIG. 1, due to the weight of the protective substrate 9. spread. At this time, it is also possible to apply appropriate pressure to the protective substrate 9.

In order to make the adhesive 8 spread so that the inner circumferential side of the adhesive 8 contacts the entire circumference of the center boss 11 as shown in FIG. The selection of the coating diameter and viscosity of the adhesive 8 shown above is important; the coating diameter must be within 1/2 of the outer diameter of the disk substrate 2, and the viscosity must be within the range of 500 to 3000 cp (25°C). Everything was appropriate. Furthermore, if the adhesive 8 is left in the state shown in FIG. The time from contacting the adhesive 8 to moving on to the next step is important. This is determined by the coating diameter, coating amount, and viscosity of the adhesive 8. Conversely, if these conditions are kept constant, the protective substrate 9 will be stacked and held for a certain period of time before moving on to the next step. As a result, there is no shortage of adhesive in the center hole of the disk, and it is possible to bond the disks without wrapping around the surfaces of the disks. At this time, the gap between the center 12 of the protective board 9 and the center boss 11 causes misalignment between the disk board 2 and the protective board 9 or the adhesive 8 wraps around, but this is determined by the degree of taper of the center boss 11. It is a thing,
It is easy to select a degree of taper that allows easy insertion of the protective substrate 9, minimizes misalignment between the two substrates, and prevents the adhesive from flowing easily. 1st
After reaching the state shown in the figure, by rotating the two substrates around the axis 5 of the rotating tool 6 as shown in Figure 3, the adhesive 8 is applied to the outer peripheral edge of the disk by centrifugal force. The adhesive 13 that spreads toward the disk and overflows from the outer peripheral edge is scattered in the direction of the arrow 14 by centrifugal force, so that it does not wrap around the disk surface. At this time, the rotation speed and rotation time of the disk are important in order to obtain an adhesive layer with a uniform thickness or to fill the entire surface of the disk.These conditions also depend on the viscosity of the adhesive, but the specific is 1000cp as adhesive
When using something with a viscosity of ~2000cp (25℃),
A predetermined adhesive layer thickness could be obtained at a rotation speed of 300 to 1000 rpm and a rotation time of 30 to 90 seconds, and the adhesive could be filled over the entire surface between the two substrates without introducing air bubbles. After the two substrates are rotated at the above-mentioned rotation speed and rotation time, they can be bonded together in a short time by irradiating them with ultraviolet rays from the direction of arrow 15 while continuing the rotation.

Next, other embodiments of the present invention will be described.

FIG. 4 shows another embodiment, in which the center boss 11' has a tapered outer shape similar to the center boss 11 shown in FIG. A hollow portion 16 is provided, and the center boss 11' is provided with elasticity, and the same effect as the center boss 11 shown in FIG. 1 can be obtained.

FIG. 5 also shows another similar embodiment, in which a recess 17 and a hole 18 that fits and slides on the shaft 5' of the rotary tool 6' are provided on the side of the center boss 11' having a larger outer diameter. A spring 19 is provided via a shaft 5' between the recess 17 and the rotary tool 6'.
This spring 19 constantly pushes the center boss 11' upward. In this embodiment, the center boss 11' is pressed against the center hole 10' of the disk substrate 2' by the spring 19, and at the same time,
Due to the elasticity of the center boss 11', the same effect as the center boss 11 shown in FIG. 1 can be obtained. The center boss 11 of the first, second and third embodiments,
A suitable material for 11' was a polymeric material to which adhesive does not easily adhere. It is also possible to chamfer or round the small diameter side of the center boss, and it is also possible to make the taper angle two steps.

Effects of the Invention When bonding two disk-shaped substrates together, the present invention provides elasticity to the center boss that aligns the two substrates and makes the external shape tapered. Even if there are variations in the diameter of the center hole or the shape of the center hole is slightly deformed from a perfect circle, the adhesive will not protrude into the center hole, and the edge of the center hole on the disk surface side will Since no adhesion occurs, the positional accuracy of the center hole is not compromised, and bonding can be performed without requiring post-processing of the center hole.

Further, by forming the tapered shape, it is easy to overlap the substrates located above, and it is also easy to remove the center boss after the adhesive has hardened.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a method of manufacturing an information carrier disk according to an embodiment of the present invention, FIGS. 2 and 3 are sectional views showing the manufacturing procedure of the same manufacturing method, and FIGS. FIG. 6 is a cross-sectional view showing another embodiment of the invention, and FIG. 6 is a cross-sectional view showing a conventional method of manufacturing an information carrier disk. 2... Disc substrate, 6... Rotating tool, 8... Adhesive, 9... Protective board, 11, 11'... Center boss.

Claims (1)

[Scope of Claims] 1. A viscous adhesive is applied to the surface of at least one of the two disk-shaped substrates near the center hole concentrically with the center hole, and the other substrate is coated with the adhesive. After sandwiching the two substrates together, the center boss fits into the center hole of the two substrates and rotates around the center boss, filling the gap between the two substrates with adhesive to bond them together. A method for manufacturing an information carrier disk using a tapered center boss that is lightly press-fitted into the center hole of one substrate and loosely fitted into the center hole of the other substrate. 2. The method of manufacturing an information carrier disk according to claim 1, wherein the center boss is always pressed against the center hole of one of the substrates from the side with the larger outer shape toward the smaller side.