JP2001084648A - Disk sticking method for stuck type optical disk and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent quality from deterioration by respectively embedding an independent heating/cooling mechanism into the inner peripheral side and the outer peripheral side of a disk holding table, separately controlling the inner and outer peripheral side heating/cooling mechanisms and straightening deformation of a substrate before irradiation by ultraviolet rays. SOLUTION: Heating/cooling pipes 2, 3 are respectively embedded into inner and outer peripheral sides of a disk holding table 1. The distribution of temperature of the disk holding table 1 itself is controlled by circulating a coolant such as water adjusted at an optional temperature through the heating/cooling pipes. In this device, after a substrate whose hardening is finished is discharged, the disk holding table on an index table is transferred to plural positions and is returned to a substrate throwing position again. The heating/cooling mechanism is provided in a lower part of the plural positions, and the disk holding table is controlled at the suitable temperature by coming into contact with the mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method and apparatus in a manufacturing process of a bonding type optical disk such as an LD and a DVD. The deformation of the substrate due to the temperature difference in the laminating step, such as the deformation due to the temperature difference of the substrate, is made as small as possible, so that the quality of the finished substrate can be effectively prevented from lowering.

[0002]

2. Description of the Related Art With the recent increase in demand for large information amount removable media, a conventional CD (compact disk)
The market demand for DVDs (digital video discs) having a storage capacity of about 6 to 8 times that of the above is increasing. This DV
In D, a 0.6 mm thick thin substrate provided with an information recording layer on one side is bonded to another light-transmitting thin substrate to form one bonded optical disk. DVDs are roughly classified into several types according to the configuration of the information recording layer.
DVD-9 having two information recording layers and a DV capable of reversible recording with a single-layer information substrate facing both sides.
D-10 and the like. The production of these laminated optical disks is performed in the following procedure. First, apply an adhesive to one or both of the thin substrates, overlay both substrates,
It is rotated at a high speed by, for example, a rotating device to form an adhesive layer having a uniform thickness on the bonding surface while shaking off excess adhesive. Next, the rotation is stopped, and then sent to a device for curing the adhesive layer of the two thin substrates adhered through the adhesive (for example, an ultraviolet irradiation device in the case of an ultraviolet-curable adhesive), and the adhesive is cured to obtain one sheet. Is completed. In addition, the procedure of the conventional laminating method is the sequence of steps of adhesive application, superposition, shaking, and curing of the adhesive. The movable disk holding table (a predetermined concentric line on the outer peripheral portion of the index table). One of the base materials is placed on the disk holding table and held, and while the disk holding table is being rotated at a low speed, an ultraviolet curable adhesive is dropped and applied in a ring shape. The substrates are overlapped, the disc holding table is rotated at a high speed, the adhesive is diffused between the vertically stacked substrates by centrifugal force, and the excess adhesive is discharged to the outer periphery, and then the substrate is The adhesive is cured by irradiating ultraviolet rays from above with an ultraviolet lamp, and the two substrates are bonded to each other.

If the irradiation of ultraviolet rays is uniform over the entire surface of the substrate, the adhesive cures at a uniform rate over the entire surface of the substrate and the adhesion is uniform over the entire surface. Therefore, the curing speed of the adhesive is not uniform, and the bonding and bonding are not uniform over the entire surface. Japanese Patent Application Laid-Open No. H10-334521 discloses an invention which solves this problem by rotating the disk holding table to uniformly irradiate the entire surface of the substrate when irradiating the ultraviolet light, and irradiating the outer peripheral surface with the ultraviolet light from the radial outer side. Have been. SUMMARY OF THE INVENTION The present invention is intended to make ultraviolet irradiation uniform over the entire surface and to prevent quality deterioration of a finished bonded product due to uneven bonding. Deformation due to non-uniform temperature distribution or temperature difference between the upper and lower substrates, in addition to non-uniform irradiation of ultraviolet rays, results in deterioration of the quality of the finished bonded product due to the deformation.
That is, in the conventional method, an ultraviolet curable resin type adhesive (radical polymerization or cationic polymerization adhesive) is used as an adhesive, and ultraviolet rays are irradiated with an ultraviolet irradiation device to cure the adhesive. The substrate is easily deformed by the heat generated by the irradiation. This is because a thin substrate with a thickness of 0.6 mm is greatly affected by heat, and there is a difference in the degree of thermal deformation when laminating substrates with different constituent layers. Therefore, it warps in either direction like a thermostat made of a bimetal material. It is presumed to be due to this. Since the adhesive is cured and adhered in such a deformed state, the quality of the finished substrate is significantly reduced. In addition, “warpage” in the substrate bonding process is largely due to a difference in temperature between the two substrates to be bonded. In addition, the degree of "warpage" of the cured substrate is greatly affected by the temperature distribution of the substrate during irradiation with ultraviolet light (temperature difference between the inner and outer circumferences).

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for preventing the quality of a laminated optical disk from deteriorating due to a temperature difference.
A bonding method to reduce thermal deformation of the substrate during ultraviolet irradiation and to correct the deformation of the substrate caused by molding and previous processes, and to correct deformation due to aging due to storage, etc. It is an object to devise a bonding apparatus.

[0005]

Means taken to solve the problem are as follows: (a) The inner circumference of the disk holding table is premised on the bonding method in the manufacturing process of the bonding type optical disk such as LD and DVD. Independent heating / cooling mechanisms are buried on the side and the outer side, respectively. (B) The heating / cooling on the inner side and the outer side are separately controlled to prevent deformation of the substrate placed on the disk holding table. This is to correct before ultraviolet irradiation.

[0006]

By independently controlling the heating / cooling of the heating / cooling mechanism independently embedded on the inner and outer peripheral sides of the disk holding table, the upper surface of the disk holding table (substrate mounting surface) ) Can be appropriately adjusted, and by adjusting the temperature distribution on the upper surface of the disk holding table (substrate mounting surface), the deformation of the mounted substrate can be corrected. Can be eliminated, and the temperature difference between the upper and lower substrates caused by the irradiation of ultraviolet rays can be compensated. Therefore, the deterioration of the quality of the bonded product can be reduced as much as possible.

[0007]

Embodiment 1 In Embodiment 1, the heating / cooling mechanism in the above solution is a fluid heating / cooling mechanism using a heat medium such as water flowing through a ring-shaped flow path, and the flow rate and temperature of the heat medium are separately controlled. Thus, the deformation of the substrate placed on the disk holding table is corrected before the ultraviolet irradiation.

The heating / cooling mechanism is a heating / cooling mechanism using a heat medium such as water flowing in a ring-shaped flow path, thereby increasing the heating / cooling capacity and controlling the flow rate and temperature. Since the cooling / heating rate can be adjusted with good responsiveness, the temperature distribution of the disk holding table can be quickly and easily controlled. In addition,
The above-mentioned "flow path" means a path for circulating a fluid such as a pipe.

[0008]

[Embodiment 2] Embodiment 2 is that the heating / cooling mechanism in the above solution means is constituted by a Peltier element (a thermo module utilizing the Peltier effect).

The Peltier element cools one side of the element by applying a DC voltage of several volts to the element, and is already commercially available. However, this element is obtained by changing the polarity of the applied voltage. Since both cooling and heating can be supported, switching between heating and cooling on the inner and outer sides can be performed easily and quickly, and the temperature distribution of the disk holding table can be controlled according to the condition of the substrate. Responding quickly and easily.

[0009]

Embodiment 3 Embodiment 3 is that the heating / cooling mechanism in the solution means 1 is provided in a station different from the disk holding table in the ultraviolet irradiation step.

Since the movable table is heated / cooled in a station different from the disk holding table in the ultraviolet irradiation step, the temperature of the disk holding table is adjusted and the temperature distribution is adjusted before the irradiation of the ultraviolet light, and the deformation due to the temperature difference is performed. After the correction, ultraviolet irradiation can be performed.

[0010]

Next, an embodiment will be described with reference to the drawings. FIG. 1 shows an example in which heating / cooling pipes 2 and 3 are buried on an inner peripheral side and an outer peripheral side, respectively, of a disk holding table 1 in an ultraviolet irradiation step in a substrate bonding apparatus. By circulating a coolant such as water adjusted to an arbitrary temperature through the heating / cooling pipe, the temperature distribution of the disk holding table 1 itself is controlled. FIG. 2 shows an example in which a module in which Peltier elements are arranged in a circular shape as a heating / cooling mechanism is embedded instead of the heating / cooling pipe. The Peltier device cools one side of the device by applying a DC voltage of several volts to the device, and is already commercially available. In this element, cooling and heating can be easily switched by changing the polarity of the applied voltage, and the heating / cooling capacity can be quickly adjusted by adjusting the applied voltage. In this embodiment, the inner peripheral side Peltier element module 4 is configured by connecting 24 identical Peltier elements in series in a circular shape, and the outer peripheral side Peltier element module 5 is similarly configured by connecting 48 identical Peltier elements in a circular shape. They are connected in series. In both cases, heating / cooling is performed by applying a DC voltage to the electrode coming out of the terminal Peltier element. FIG. 3 shows an ultraviolet irradiation apparatus using an index table. There are six movable disk holding tables 7 in the index table 6 divided at every central angle of 60 degrees. This table is a simple plate without the heating / cooling mechanism of the present invention.

The substrate w that has flowed from the previous process is transferred to the position (a) on the index table 6 by the input arm 8, and then the index table 6 is moved clockwise by 6 degrees.
The substrate w is rotated by 0 degrees and is transferred to the position (b). Here, after being irradiated by the ultraviolet irradiation device 9, the index table 6 is rotated again and transferred to the position (c). The cured substrate w is transferred to a subsequent process by the discharge arm 10. However, a movable disk holding table 7 for holding the substrate remains at the position (c) where the substrate has disappeared. The table 7 is thereafter moved to the position (d), the position (e), and the position (f), and returns to the position (a) again. Here, below the positions (d), (e), and (f) of the index table 6, the above-mentioned heating / cooling mechanism is provided (not shown). Controlled by temperature.

FIG. 4 shows a laminating apparatus to which an inner peripheral temperature sensor 11 for exclusively measuring the temperature of the inner peripheral portion of the disk holding table 1 and a similar outer peripheral temperature sensor 12 are added. By installing these sensors 11 and 12 at the position (c) or the position (d) in FIG. 3, the heating / cooling mechanism below the position (d), the position (e), and the position (f) It is possible for the temperature control means 13 to perform the optimal control with the temperature feedback applied to H. In this case, the automatic control is performed based on the temperature difference between the upper and lower substrates caused by the ultraviolet irradiation, and the temperature difference between the upper and lower substrates at the stage of curing the adhesive by the ultraviolet irradiation regardless of the temperature rise of the disk holding table. What is necessary is just to perform according to the control flow programmed beforehand so that the temperature difference of a peripheral part and an outer peripheral part may become zero as much as possible. Further, when it is necessary to correct deformation due to temporal change due to storage or the like, the temperature control flow of the inner peripheral portion and the outer peripheral portion may be programmed in consideration of the degree of deformation of each substrate.

[0013]

The present invention has been described above. The effects of the present invention are summarized as follows. 1. According to the laminating method according to the first aspect of the present invention, the temperature of the inner peripheral side and the outer peripheral side of the disk can be controlled independently. It is possible to freely control the minus side. By cooling both inside and outside of the table, thermal deformation of the substrate due to heat storage of the disk holding table due to repeated ultraviolet irradiation is reduced. In addition, it is possible to correct deformation due to temporal change due to storage or the like, and to obtain a high-quality bonded optical disc.

2. Regarding the invention according to claim 2, according to the invention according to claim 2, the heating / cooling mechanism according to claim 1 is heated / cooled by a heat medium such as water flowing through a ring-shaped flow path.
It is a cooling mechanism, but the heating / cooling mechanism heating /
Since the cooling capacity can be increased and the cooling / heating rate can be adjusted with good responsiveness, the temperature distribution of the disk holding table can be quickly and easily controlled.

3. Regarding the invention according to claim 3 According to the invention according to claim 3, the heating / cooling mechanism according to claim 1 is configured by a Peltier element (a thermo module utilizing the Peltier effect). In addition to the effects, the size of the device can be reduced as compared with a system for circulating cooling water / hot water. Further, since the Peltier device only applies a DC voltage, the connection between the table in which the device is embedded and the controller can be performed with a connector having two points, a positive pole and a negative pole, and a total of four connectors on the inner and outer sides. Therefore, if four slip rings are used, the disk holding table itself can be rotated. 4. Regarding the invention according to claim 4, the invention according to claim 4 is that the heating / cooling mechanism in the solution means 1 is provided in a station different from the disk holding table in the ultraviolet irradiation step. The degree of freedom in designing the heating / cooling station is greater than in the case where a holding table is provided.
The number of cooling stations can be increased to two or three, and the heating / cooling effect of the disk holding table can be enhanced. Therefore, it is possible to cope with shortening of the device tact.

5. The invention according to claim 5 The invention according to claim is a bonding type optical disk bonding apparatus to which the invention according to claims 1 to 4 is applied. Can be produced with high efficiency.

6. According to a sixth aspect of the present invention, there is provided the bonding apparatus for a bonding type optical disk according to the fifth aspect of the present invention, wherein a sensor for measuring a temperature of an inner peripheral portion and an outer peripheral portion of the disk and a temperature output thereof are provided. The controller is added to automatically control the heating / cooling of the stage to the optimal value on the basis of the temperature. Since it is stably controlled to a predetermined state, it is possible to stably produce a high-quality bonded optical disc without warpage.

[Brief description of the drawings]

FIG. 1A is a plan view of a disk holding table according to a first embodiment, and FIG. 1B is a sectional view taken along line XX of FIG.

FIG. 2 is a plan view of a disk holding table according to a second embodiment.

FIG. 3 is a plan view showing a step of irradiating the laminated optical disk with ultraviolet light.

FIG. 4 is a side view schematically showing a bonding apparatus provided with a temperature sensor.

[Explanation of symbols]

 1: disk holding table 2: inner peripheral side heating / cooling pipe 3: outer peripheral side heating / cooling pipe 4: inner peripheral side Peltier element module 5: outer peripheral side Peltier element module 6: index table 7: disk holding table (movable type) 8: Input arm 9: Ultraviolet irradiation device 10: Discharge arm 11: Inner peripheral temperature sensor 12: Outer peripheral temperature sensor 13: Temperature control means H: Heating / cooling mechanism w: Substrate

Claims (6)

[Claims] In a disk bonding method in a manufacturing process of a bonded optical disk such as an LD or a DVD, independent heating / cooling mechanisms are embedded on the inner and outer peripheral sides of a disk holding table, respectively. A disk bonding method in which heating / cooling on the outer peripheral side and the outer peripheral side are separately controlled to correct deformation of a substrate placed on a disk holding table before irradiation with ultraviolet rays. 2. The heating / cooling mechanism is a heating / cooling mechanism using a heat medium such as water flowing through a ring-shaped flow path, and the flow rate and the temperature of the heat medium are separately controlled to be mounted on a disk holding table. 2. The disk bonding method according to claim 1, wherein the deformation of the substrate is corrected before the irradiation of the ultraviolet rays. 3. The disk bonding method according to claim 1, wherein said heating / cooling mechanism is constituted by a Peltier device (thermo module utilizing the Peltier effect). 4. The disk bonding method according to claim 1, wherein said heating / cooling mechanism is provided in a station different from the disk holding table in the ultraviolet irradiation step. 5. A disk bonding apparatus in a manufacturing process of a bonded optical disk such as an LD or a DVD, wherein the disk bonding method according to claim 1, 2, 3, or 4 is applied. apparatus. 6. The disc bonding apparatus according to claim 5, wherein
A disk bonding apparatus comprising: a sensor for measuring the temperature of the inner and outer peripheral portions of a disk; and control means for automatically controlling the heating / cooling of the stage constantly based on the temperature output of the temperature sensor.