JPH10134427A - Method for taking up memory disk from holding base and holding base used for the purpose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for taking up a memory disk which obviates the occurrence of the misalignment of two sheets of circular resin disks from each other. SOLUTION: This method for taking up the memory disk is method of taking up the memory disk placed on a holding base in the state of inserting its boss part into its central hole by means of expansion chucks. The stages consist of a stage for pushing the boss part 1 downward on the rear surface of the expansion chucks 5 by lowering the expansion chucks 5, thereby inserting the expansion chucks 5 into the central hole of the memory disk D, a stage for expanding the expansion chuck 5 to press the central hole DH of the memory disk D, thereby holding the memory disk and a stage for rising the expansion chucks 5 while holding the memory disk D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of bonding storage disks, and more particularly, to a method for picking up a storage disk and a holding table used for the method.

[0002]

2. Description of the Related Art In recent years, computers, especially personal computers, etc., have become remarkably widespread, and the storage media used for them, particularly storage disks, have been increasing in density and their types have been increased, and their application fields have been increasing. It is expanding. For this reason, for example, CDs mainly for music use have recently tended to develop to video use. As the storage disk, for example, a magnetic disk, an optical disk (for example, a CD-ROM), a magneto-optical disk (for example,
O), among which, the demand for optical disks has recently increased.

[0003] Taking an optical disk called a DVD as an example, a circular resin substrate as a single plate constituting the optical disk has a thickness of 0.6 mm, an outer diameter of 120 mm, and a center hole D.
It is specified that the diameter of H is 15 mm. Since such a thin circular resin substrate has low mechanical strength and is easily deformed, it is used by bonding together such circular resin substrates having the same thickness (0.6 mm).

For example, FIG. 7 schematically shows a DVD which is an optical disk in a state where two circular resin substrates (a first circular resin substrate 2 and a second circular resin substrate 1D) are bonded together. (A) shows the information signal applied to one of the circular resin substrates, and (b) shows the information signal applied to both the circular resin substrates. The optical disk D on which the two circular resin substrates D1 and D2 are bonded in this manner is a device for reproducing a signal by receiving light reflected from the reflection film a using a laser beam with a photodetector (not shown) or the like. It is.

As described above, many high-density storage disks including optical disks such as DVDs are used not as a single plate but as a plywood structure as described above. Naturally, it is necessary to bond the second circular resin substrate D2. The following series of steps (STEP) are performed to bond the veneers to form an integrated storage disk (that is, an optical disk here) (see FIG. 6).

(1) The first circular resin substrate D
First, in this step (1), a first circular resin substrate D1 having a signal surface coated with a reflective film and a protective film and applied with an information signal is placed on a rotation holding table X and uniformly adsorbed. Will be retained.

(2) Step of Applying Adhesive R to First Circular Resin Substrate D1 In this step (2), the rotation nozzle X on which the first circular resin board D1 is mounted is rotated at a low speed while the discharge nozzle N The adhesive R, for example, an ultraviolet curable resin is discharged more gently.
The trajectory of the adhesive R to be discharged onto the first circular resin substrate D1 differs depending on the manner in which the discharge nozzle N moves. For example, it is preferable to form the adhesive R as a donut-shaped trajectory as shown in the figure.

(3) Step of placing the second circular resin substrate D2 on the first circular resin substrate D1 and superimposing them In this step (3), the first circular resin substrate D1 on which the adhesive R is applied is placed on the first circular resin substrate D1. The (transparent) second circular resin substrate D2 is mounted. Here, the second circular resin substrate D2 may be a transparent substrate to which no information signal is applied, or a substrate to which an information signal is applied (in this case, the substrate is usually not transparent because it has a reflective film). In the drawing, the second circular resin substrate D
2, a nail chuck is used, but the surface is often suction-held by a suction chuck.

(4) Step of extending adhesive R interposed between both circular resin substrates D1 and D2 Next, in this step (4), the adhesive R interposed between both circular resin substrates D1 and D2 is evenly distributed. In addition, the spread is performed so as to be evenly distributed. In this extension, the rotation holding table X is rotated at a high speed in a state where the optical disk D is mounted, that is, the combined circular resin substrate in which the two circular resin substrates D1 and D2 are combined (normally, the rotation speed is several thousand rpm or more, (Rotation time is about several seconds).

[0010] By this rotation, the excess adhesive R existing between the superposed circular resin substrates D1 and D2 is discharged to the outside together with the spreading, and at the same time, the two circular resin substrates D1 and D2 are superposed.
The air (such as air bubbles) trapped in between is discharged to the outside. At this time, the adhesive is sucked in the center direction from the boss 1 of the rotary holder inserted into the center holes of the circular resin substrates D1 and D2 during the extension. This suction is performed with a suction force such that the adhesive reaches the position of the liquid stopping groove and the position of the center hole provided in the circular resin substrate.

(5) Complete curing step 0 for curing the spread adhesive R In this step (5), after the spread of the adhesive between the first circular resin substrate D1 and the second circular resin substrate D2 is completed. The optical disc is slowly rotated (the rotation speed here is substantially lower than the rotation speed in the spreading step, for example, about 0 rpm), or in a state where the optical disc is not rotated, the adhesive is irradiated with ultraviolet rays, and the adhesive R, for example, The ultraviolet curing resin layer is cured. More specifically, curing is efficiently performed by irradiating ultraviolet rays from an ultraviolet light source body L having a reflecting mirror M on the back surface. By this extension step, the entire adhesive between the two circular resin substrates is hardened, and the two circular resin substrates are entirely fixed.

The curing step differs depending on the type of the adhesive R used, and it goes without saying that a curing method suitable for the characteristics of the adhesive 8R used is employed. Also,
This curing step is often performed at a different station from the spreading step. The bonding step is completed as described above.

By the way, in the case of a storage disk of a standard in which an information signal is recorded on both the first circular resin substrate D1 and the second circular resin substrate D2, when outputting from the storage disk, light beams are transmitted from one direction. (For example, a method of reading a storage disk of a standard used for a dual layer DVD corresponds to this), and a method of reading a signal of each substrate by irradiating light from both directions (single layer) , Double-sided).

In the former case, if there is a deviation between the first circular resin substrate D1 and the second circular resin substrate D2, the applied information cannot be accurately read. FIG. 5 shows a state in which the two circular resin substrates are displaced. In such a displaced state, the applied recording information is also displaced between the two, and the two pieces are bonded as they are. Then, accurate reading cannot be performed by the reading method from one direction.

By the way, according to the standard of the dual layer DVD, it is desirable that the difference between the two be within 15 microns, for example, so as not to be defective. Such a displacement between the circular resin substrates is caused by the first circular resin substrate D1 of the rotation holding base in the third step described above.
This occurs when the second circular resin substrate D2 is superimposed on the substrate. Therefore, in the subsequent spreading step, the adhesive R is spread on the rotary holding table while the two circular resin substrates are shifted and overlapped.

In the extension step, the boss 1
Are inserted into the center holes DH of the two circular resin substrates, and the positioning of the two circular resin substrates is temporarily performed. However, the outer diameter of the boss body 1 and the diameter of the center hole DH of the circular resin substrate are determined by inserting and removing the circular resin substrate. Therefore, the boss 1 cannot correct a minute displacement between the two resin substrates. Therefore, even after the extension has been completed, this deviation may not be corrected and may remain as it is. Further, in the above-mentioned third step, even if there is no deviation between the first circular resin substrate D1 and the second circular resin substrate D2, the adhesive R is extended by rotating the rotation holder X. Of course, it may occur at the stage of causing it to occur.

In some cases, no displacement occurs even when the extension is completed on the rotary holding table. In this case, too, the surface is attracted, and when the process is moved to the next step, the displacement occurs in the process of the movement. May occur. Mutual displacement of these circular resin substrates must be reliably eliminated in order to ensure quality. On the other hand, in the case of a storage disk such as a DVD having a large storage capacity to which the storage capacity is applied precisely, it is important to hold the storage disk as much as possible without sucking the surface so as not to damage the storage disk. As a method for holding the storage disk, there are a method in which the periphery of the storage disk is pressed and gripped by the claw chuck, and a method in which the surface of the storage disk is suctioned and held by the suction chuck. It has the disadvantage that it is easily damaged, and the latter may damage the surface.
For this reason, a method of holding from the center has been desired, but it has been difficult because the rotary holding table has a boss for positioning.

[0018]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems in the background described above. That is, an object of the present invention is to provide a method for picking up a storage disk so that two circular resin substrates do not shift from each other, and a holding table used for the method. A further object is to provide a method for picking up a storage disk with a center hole in the storage disk and a holding table used therefor.

[0019]

Means for Solving the Problems The inventors of the present invention have made intensive studies on such problems, and as a result, have developed a chuck for picking up the boss body by making the boss body vertically resiliently movable. The inventor has found that it can be inserted into the center hole of the storage disk, and has completed the present invention based on this finding.

That is, the present invention provides (1) a method of picking up a storage disk placed on a holding table with an expansion chuck in a state where a boss is inserted into a center hole. Pushing down the boss on the lower surface of the expansion chuck to insert the expansion chuck into the center hole of the storage disk; expanding the expansion chuck and pressing the center hole of the storage disk to hold the storage disk; The pick-up method includes a step of raising the expansion chuck while holding the disk.

(2) A holding table for mounting a storage disk having an adhesive interposed between two circular resin substrates having a center hole, wherein the holding table is composed of the two circular resin substrates. And a boss inserted into the center hole of the circular resin substrate, and the boss is resiliently movable up and down on the holder.

Further, (3), the boss body is set so as to be able to descend to a position below the surface of the holding table (2).
In the holding table.

Further, (4) the boss exists in the holding table of (2) having a suction function.

Further, (5) the surface of the holding table has the holding table of the above (2) having a suction function.

Further, (6) the present invention resides in the above-mentioned holding table (2) in which the holding table is rotatable.

Further, (7) the suction function of the boss body and the suction function of the holding table exist in the holding table of (2) in which the suction source is performed through different paths.

[0027]

The extension chuck is lowered to push down the boss body, the extension chuck is inserted into the center hole of the storage disk, and the boss body is simultaneously pulled out from the center hole. By expanding the expansion chuck, the inner peripheral surface of the center hole of the storage disk is pressed outward and held. After holding the storage disk, the extension chuck is raised as it is.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method of picking up a storage disk from a holding table X according to the present invention, an expansion chuck located above the holding table is used. The holding table of the present invention includes a rotating holding table used in the spreading step of spreading the adhesive, and other non-rotating holding tables.

[First Embodiment of the Invention] FIG. 1 shows a holding table (here, referred to as a rotation holding table for rotation) used in an extension process and an expansion means for holding and lifting a storage disk. It is an outline sectional view. FIG.
(A) is a plan view and (b) is a view showing a rotation holding table.
Is a side view. The storage disks D (both circular resin substrates D1 and D2) superimposed via the adhesive R are mounted on the upper surface of the circular rotary holder X as indicated by the chain line in FIG. A large number of suction holes (not shown) for sucking the circular resin substrate are provided on the upper surface of the rotation holding table X, and suction control is performed with a predetermined strength. A boss 1 is provided at the center on the rotation holding base X, and the boss 1 is a portion to be inserted into the center hole DH of the circular resin substrate.

The rotation support X is controlled to rotate at a high speed by a driving device including a motor (not shown). Around the rotation support X, scattering prevention means X1, which is a cover having a circular dome shape, is provided. The scattering prevention means X1 is for receiving the adhesive R discharged outward from the two circular resin substrates at the time of spreading to prevent the scattering, and a detailed description thereof will be omitted.

As shown in cross section in FIG. 1, the rotary holding table X includes a table body 2 for mounting the circular resin substrates D1 and D2, and a rotation support shaft 3 for supporting the table body 2.
And The table 2 has a large diameter portion 3 of the rotation support shaft 3.
It is attached by being fitted into 1. Further, a boss body 1 described later is fitted and fitted in a fitting hole 32 provided in the large-diameter portion 31 of the rotation support shaft 3, and can resiliently slide vertically in the fitting hole 32. Rotary support shaft 3
Is rotatably supported by the fixed sleeve 4 via the bearing 41.

The space A4 is formed as a cylindrical space sealed between the rotation support shaft 3 and the fixed sleeve 4. The space A4 is strictly hermetically sealed between the fixed sleeve 4 and the rotation support shaft 3 by using, for example, a seal body 42. In addition, this space A4 is
Are connected to a controlled negative pressure source (not shown) (for example, a vacuum suction device is adopted as the negative pressure source) through through holes (not shown) provided at appropriate vertical positions.

A pulley (not shown) and a transmission belt (not shown) are provided at the lower end of the rotation support shaft 3 so that it can rotate. As the rotation support shaft 3 rotates, the entire rotation support X is integrally rotated. A further lower end of the rotary support shaft 3 is connected to a rotary joint, and an internal passage B3 is connected to an external controlled negative pressure source (not shown, for example, a vacuum suction device) through the rotary joint. To be adopted).

On the other hand, the table 2 is a portion (mounting portion) on which the storage disk D is directly mounted, and has a flat seating surface. A large number of suction holes A1 are provided on the surface of the rotation support shaft 3. The suction holes A1 communicate with the passage A3 of the large-diameter portion 31 of the rotary support shaft 3 via the passage A2 in the table.

The passage A3 is open to the space (gap) A4 between the rotation support shaft 3 and the fixed sleeve 4. As described above, the continuous suction passage for sucking the storage disk includes the suction hole A1, the passage A2, the passage A3,
The space A4 is formed. By operating a negative pressure source (not shown) communicating with the space A4, the suction hole A1 becomes a negative pressure, and a suction force acts on the surface (seating surface) of the table body 2 as a mounting portion, and the mounting portion is placed thereon. The stored storage disk D is suction-held.

Next, the boss body will be described. FIG. 3 shows a state where the boss body is disassembled into two main parts, that is, a base part 11 and a lid part 12. As shown in the figure, the boss body 1 includes a base portion 11 and a lid portion 12, both of which are integrally attached to each other by screwing a communicating bolt body P. The bolt body P serves as a support portion when the spring body F is mounted in the fitting hole 32 of the large-diameter portion 31 of the rotation support shaft 3.

Although the outer peripheral surface of the lid portion 12 is shown as having a tapered surface T, this tapered surface is not always necessary in the present invention. The base 11 includes a lower cylindrical portion 11A having a smaller diameter and a second cylindrical portion 11 having a larger diameter.
B. The shoulder at the boundary between the two cylindrical portions is 11C, and the boss body 1
This is a portion that resiliently abuts against the lower surface of the table body 2 when it is mounted in the fitting hole 32 to prevent it from coming off. The base 11 is
With the lid attached to the upper side, the fitting hole 32
And a radial projection 111 is formed on the upper surface thereof. At the bottom of the crotch portion of the protrusion 111, a small hole 112 is provided for suction,
This small hole 112 is opened to the boss body 1, specifically, the internal space B2 of the base 11.

The internal space B2 of the boss 1 is
Is connected to the passage B3 penetrated through the hole.
By the way, in a state where the lid portion 12 is fitted on the base portion 11 from above, the back bottom surface of the lid portion 12 is
Abuts on the outer peripheral surfaces of the two to form a suction port B1 (see FIG. 1). Suction port B1
Communicates with the internal space B2 of the boss 1 through the small hole 112 of the boss 1 and, as described above, the internal space B2
Is connected to a passage B3 penetrated by the rotation support shaft 3.

The adhesive is sucked from the suction port B1 by the operation of the negative pressure source communicating with the passage B3. The gap formed between the base 11 and the lid 12, that is, the suction port B1, is formed continuously around the entire periphery of the boss body, and a uniform suction force acts in all directions. The boss body 1 described so far.
Is a boss 1 that can be separated into a base 11 and a lid 12, but if there is no restriction on processing, the base 11 and the lid 1
Of course, it is also possible to form a boss body in which the two are integrated.

In order to assemble the rotation holding table X, first, a boss body, which will be described later, is fitted into a fitting hole 32 formed in the large-diameter portion 31 of the rotation support shaft 3. At this time,
Bolt body P screwed to boss body 1 and bottom surface 3 of fitting hole 32
A spring body F is interposed between the spring body 2A and the boss body 1 and the spring body F is compressed. And the rotation support shaft 3
The concave portion 21 of the table body is inserted into the small-diameter cylindrical portion 33 of the large-diameter portion 31.
Is inserted. The boss body 1 is mounted in a state where its shoulder is pressed by the lower surface of the table body 2 and is urged upward.

As described above, the boss body 1 is connected to the rotation holder X
Is vertically resiliently mounted in the fitting hole 32 of the above. As described above, the boss body 1 has a function of sucking the adhesive while being inserted into the center hole of the storage disk in the extension step. The continuous suction passage for suctioning the adhesive includes a suction port B1 and a small hole 1.
12, an inner space B2 of the base 11, a fitting hole 32 of the rotation support shaft 3, a passage B3, and the like. The passage B3 is connected to a negative pressure source (not shown) (preferably, a negative pressure for sucking the suction hole A1 described above). (Use a negative pressure source different from the pressure source).

By operating this negative pressure source, the suction port B
A predetermined suction is performed from 1. In addition, this suction function is to perform an action of helping the adhesive interposed between the first circular resin substrate D1 and the second circular resin substrate D2 to extend in the direction of the center hole DH by drawing inward. The present inventors have already applied for a technique in this regard. When the storage disk D is mounted, the space S is formed between the boss 1 and the upper surface of the large-diameter portion of the rotation support shaft 3 and the lower surface of the storage disk D.
Are formed. The space S is opened to the outside by an introduction path (not shown) provided in the large-diameter portion 31, and serves as a portion for introducing outside air when suctioning from the boss body 1.

Next, the extension chuck Y used when picking up the storage disk from the holding table will be described. The expansion chuck Y is disposed above the rotary holding table X, and sucks the storage disk placed on the holding table and transfers it to another station. Extended chuck Y
Comprises a cylindrical part 5 inserted into the storage disk D,
This cylindrical portion 5 is divided into a plurality of divided pieces. Although the figure shows an example in which the cylindrical portion 5 is divided into two divided pieces 5A and 5B, the number of divided pieces is not limited to two. Each split piece 5
As A and 5B move outward, the expansion chuck Y is in an expanded state. The expansion structure of the expansion chuck is described in, for example, Japanese Patent Application No. 8-21 filed by the present inventors.
No. 9470 boss body expanding structure may be adopted. Each of the divided pieces 5A and 5B is set in a state of being urged outward. Therefore, when each of the divided pieces 5A and 5B moves outward, each of the divided pieces 5A and 5B can be expanded while maintaining the elastic pressure, and the degree of the expansion can be freely set.

The expansion chuck Y is in a contracted state (normal state) when the divided pieces 5A and 5B come into contact with each other and become integrated. In the reduced state, the outer diameter of the expansion chuck Y is set to be slightly smaller than the diameter of the center hole DH of the storage disk D. Therefore, the extension chuck Y
Can be inserted into the center hole DH of the storage disk D,
Also, by expanding in that state, it can be retained. That is, when the expansion chuck Y is expanded,
Since the divided pieces 5A and 5B are elastically maintained, the inner peripheral surface of the center hole DH of the storage disk D can be pressed with a constant pressure.

Next, the extension chuck Y as described above is used.
A method of picking up the storage disk D using the rotation holding table X described above will be described. FIG. 4 is a diagram showing a method of picking up the storage disk from the rotary holder in the order of steps. (Extension Chuck Lowering Step) At the stage where the spread of the adhesive on the rotary holder X is completed, the storage disk D is left as it is, that is, the boss 1 of the rotary holder X is inserted into the center hole DH of the storage disk D. Is placed in a state where is inserted.
[Fig. 4 (1)]

In this state, it is assumed that the circular resin substrates D1 and D2 of the storage disk D are mounted with a displacement. The extension chuck Y is usually waiting just above the rotation holding table X. Now, the extension chuck Y is lowered. Extended chuck Y
Is lowered to a certain position, the lower surface of the expansion chuck Y presses the upper surface of the boss. When the extension chuck is further lowered, the boss body is also pushed down integrally therewith.
As a result, the expansion chuck Y is inserted into the center hole DH of the storage disk D, and the boss 1 is pulled down from the center hole DH. When the extension chuck Y enters a predetermined insertion state, the movement of the extension chuck Y is stopped. [FIG. 4 (2)] (Storage disk holding step)

Next, the expansion chuck Y is expanded, and the center hole of the storage disk is pressed outward on the outer peripheral surface thereof to be held. [FIG. 4 (3)] At this time, the two circular resin substrates D1 and D of the storage disk D
The gap between the two is corrected. (Extension Chuck Elevation Step) The extension chuck is raised this time while holding the storage disk. The storage disk held by the expansion chuck rises integrally. [FIG. 4 (4)] Thus, the step of picking up the storage disk from the rotary holder is completed.

As described above, since the storage disk is picked up with the center hole held by the expansion chuck, the storage disk has an extremely excellent advantage, unlike the conventional method of sucking the storage disk surface. As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various other modifications can be made without departing from the essence of the present invention. Needless to say, there is.

For example, the rotary holding table of the present invention can be used for a method of mounting a storage disk from another position. In that case, the procedure is the reverse of the method for picking up the storage disk as described above. That is, the storage disk is inserted into the center hole, and the expansion chuck holding the storage disk is positioned above the rotary holder from another point.
The extension chuck is lowered as it is, and the boss is pushed down on the lower surface. As the expansion chuck is inserted in the center hole of the storage disk instead of the boss body,
When the predetermined insertion state is reached, the lowering of the extension chuck is stopped.

Next, the expansion chuck is contracted and separated from the inner peripheral surface of the center hole of the storage disk. As a result, the storage disk is released from the expansion chuck, and the storage disk is placed on the rotary holder. Thereafter, the expansion chuck that has been reduced is raised. Since the boss body can be elastically moved upward, it rises integrally with the expansion chuck. The boss body is inserted into the center hole of the storage disk, and stops after a certain distance. Thereafter, the boss body and the expansion chuck separate from each other, and only the expansion chuck rises. Thus, the process of placing the storage disk on the rotary holder is completed.

[0051]

When the storage disk is picked up from the rotary holder, the mutual displacement between the two circular resin substrates is corrected. In addition, a storage disk in which no displacement has occurred is picked up from the rotary holding table without any displacement. Since the pickup is performed by using the center hole of the storage disk D, the surface is not damaged.

[Brief description of the drawings]

FIG. 1 is a view showing a rotation holding table and an expansion chuck for holding and lifting a storage disk, and the rotation holding table is shown in a schematic sectional view.

FIGS. 2A and 2B are diagrams showing a rotation holding table, wherein FIG. 2A is a plan view and FIG. 2B is a side view.

FIG. 3 is an exploded view of a boss body.

FIG. 4 is a process chart showing a method of picking up a storage disk.

FIG. 5 is a diagram showing a state in which two circular resin substrates are displaced (a front view and a side view).

FIG. 6 schematically shows a series of steps for bonding single plates to form an integrated optical disk.

FIG. 7 is a schematic cross-sectional view showing a storage disk (for example, a DVD which is an optical disk).

[Brief description of the drawings] [Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Boss body 11 ... Base part 112 ... Small hole 111 ... Projection part 11A ... 1st cylindrical part 11B ... 2nd cylindrical part 12 ... Cover part 2 ... Table body 3 ... Rotation support shaft 31 ... Large diameter part 32 ... Fitting hole 4 ... Fixing sleeve 5 ... Cylindrical part 5A ... Split piece 5B ... Split piece A1 ... Suction hole A2 ... Path A3 ... Path A4 ... Space B1 ... Suction port B2 ... Internal space B3 ... Path D ... Storage disk (optical disk) D1 ... First Circular resin substrate a ... Reflection film b ... Protective film D2 ... Second circular resin substrate DH ... Center hole F ... Spring body M ... Reflector N ... Nozzle P ... Bolt body R ... Adhesive (ultraviolet curing resin) S ... Vacancy T: tapered surface L: ultraviolet light source X: rotation holder X1: scattering prevention means Y: expansion chuck

Claims (7)

[Claims] 1. A method for picking up a storage disk mounted on a holding table with an expansion chuck with a boss inserted into a center hole, comprising the following steps (1) to (3). And how to take up. (1) Step of lowering the extension chuck, pushing down the boss portion on the lower surface of the extension chuck, and inserting the extension chuck into the center hole of the storage disk. (2) Expanding the extension chuck to remove the center hole of the storage disk. Step of pressing and holding the storage disk (3) Step of raising the expansion chuck while holding the storage disk 2. A holding table for mounting a storage disk in which an adhesive is interposed between two circular resin substrates having a center hole, wherein the holding table is composed of the two circular resin substrates. A boss inserted into the center hole of the holding base, wherein the boss is resiliently movable up and down on the holding base. 3. The holding table according to claim 2, wherein the boss is set so as to be able to descend to a position below the surface of the holding table. 4. The holding table according to claim 2, wherein the boss has a suction function. 5. The holding table according to claim 2, wherein the surface of the holding table has a suction function. 6. The holding table according to claim 2, wherein the holding table is rotatable. 7. The holding base according to claim 2, wherein the suction function of the boss body and the suction function of the holding base are performed by different suction sources.