KR100595242B1 - production method by optical disk bonding - Google Patents

Abstract

The present invention is to provide a method for solving the bubble generation problem that is a problem of bonding and optimizing the bonding conditions by adjusting the viscosity of the substrate adhesive through a simple temperature control unit, by changing the temperature of the adhesive to the adhesive A viscosity adjusting step of adjusting the viscosity of the adhesive, an adhesive applying step of applying a predetermined amount of the adhesive having the viscosity adjusted on the first substrate, a substrate placing step of depositing a second substrate on the first substrate, and the first substrate And a bonding step of hardening and bonding the adhesive having a changed viscosity between the second substrate and the second substrate, thereby preventing air bubbles and defects in the product from which the adhesive liquid is protruded.

DVD optical disc, optical disc splicing

Description

Production method by optical disk bonding

1 is an optical disk manufacturing process according to the prior art

Figure 2 (a) (b) is a block diagram of a spin-coating method according to the prior art

     (c) is a block diagram of a screen printing method according to the prior art

3 is a schematic view of a spin-coated splicer according to the prior art;

4 is an embodiment of the adhesive viscosity change according to the temperature change according to the present invention

Figure 5 (a) is a block diagram of a spin-coating adapter according to the present invention

     (b) is the first embodiment when the temperature controller is installed in the inlet pipe in Figure 5 (a)

     (c) is a second embodiment when the temperature controller is installed in the dispenser in FIG.

6 is a block diagram of a screen printing machine according to the present invention

7 is an embodiment of the effect of the manufacturing method by the optical disk bonding according to the present invention

* Explanation of symbols for main parts of the drawings

1: first substrate 2: second substrate

3: dispenser 3a: adhesive storage container

5: adhesive 6: rotating motor

7: ultraviolet curing machine 8: screen

9: presser 10: spin-coating part

11, 11a: Tray 12: UV Lamp

13: bonded substrate storage 14: robot arm

15: device control unit 16: temperature control unit

18a: inlet tube 18b: heating band

20: thermocouple 21: heating portion

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk manufacturing process, and more particularly, to an optical disk bonding in which two single-sided disks are bonded by adjusting the viscosity of a substrate adhesive.

Recently, due to the development of optical disk technology, it was originally used for recording image information (video signal) or audio signal, and is now used in computer field to manage a large amount of information such as documents.

In general, an optical disk is called a compact disk (CD), and is recorded with a storage capacity of 600 MByte in a 1.2 mm thickness and a 12 cm diameter cross section.

After the development of the CD, a lot of research has been conducted to improve the recording density of optical disks. Currently, two substrates having a thickness of 0.6 mm and a diameter of 12 cm are bonded to each other to form a DVD (digital versatile disk) having various structures for increasing the recording density, The research of various types of DVDs, such as one-time recordable DVD-R and rewritable DVD-RAM, is in full swing and a new disc market is being formed.

Next, a method of manufacturing an optical disc according to the prior art will be described with reference to the accompanying drawings.

1 is a view illustrating a manufacturing process of an optical disk according to the prior art, and a mass production of a replica substrate using a mastering process for producing a stamper (S1) and a stamper manufactured by the mastering process (S1). And a post-treatment step (S3) of joining two substrates by vacuum depositing a reflective film, a recording film, and the like onto the replica substrate manufactured by the molding step (S2), and printing the finished product. It consists of the process of packaging (S4).

One of the biggest differences between the DVD manufacturing process and the CD manufacturing process in such an optical disc manufacturing process is that the DVD manufacturing process performs a bonding process in which two substrates are glued together in the post-treatment process.

Then, in the bonding process, the process of applying the adhesive to the first substrate, the process of placing the second substrate on the first substrate, and the physical and chemical of the adhesive applied between the first substrate and the second substrate Bonding the first and second substrates by the adhesive force through the change is made.

In this process, the bonding methods developed to date can be divided into two bonding methods.

First, a spin-coating splicer method using a general dispenser for applying an adhesive and a capillary with improved bubble generation is one.

Second, the screen printing method is another method.

Description of each of the two types of bonding method and process is shown in FIG.

First, the first method, the spin-coating splicer method, includes a general dispenser method (a1) and a capillary dispenser method (a2).

Figure 2 (a) (b) is a schematic view of the spin-coating method according to the prior art, first of all see the general dispenser method (dispenser) method and the process (a) to apply the adhesive (5) to the first substrate (1) An adhesive coating step, a spin-coating step of placing the second substrate 2 on the first substrate 1 to which the adhesive 5 is applied, and performing spin-coating using the rotating motor 6, and ultraviolet rays. It consists of an ultraviolet bonding step of curing the adhesive agent 5 between the first substrate 1 and the second substrate 2 through the curing machine 7.

In addition, in the capillary dispenser method and process, (b) the first substrate 1 and the second substrate 2 are brought close to each other, and then the capillary capillary 4 is used to Applying an adhesive (5) between the second substrate (2), placing the second substrate (2) on the first substrate (1) to which the adhesive (5) has been applied, and using a rotating motor (6) A spin-coating step of spin-coating and an ultraviolet bonding step of curing the adhesive agent 5 between the first substrate 1 and the second substrate 2 through the ultraviolet curing machine 7.

The second method, a screen printing method of the bonding machine will be described as follows.

FIG. 2 (c) is a block diagram of a screen printing method according to the prior art. Referring to FIG. 2 (c), the screen plate 8 is placed close to the first substrate 1, and the adhesive is formed on the screen plate 8. 5) putting the adhesive (5) on the first substrate (1) through the hole formed in the screen plate (8) while moving the pressing machine (9) from side to side on the mounting step (5) And curing the first substrate 1 to which the adhesive 5 has been applied using an ultraviolet curing machine 7, and placing a second substrate 2 on the cured first substrate 1 Joining the first substrate 1 and the second substrate 2 is performed.

3 shows a schematic diagram of a spin-coating splicer according to the related art. Referring to FIG. 3, the first substrate 1 is placed on the spin-coating unit 10 using the robot arm 14.

When the first substrate 1 is placed on the spin-coating unit 10, the dispenser 3 approaches the first substrate 1, receives the adhesive 5 from the adhesive storage container 3a, and the first substrate 1. The said adhesive agent 5 is apply | coated to (1).

Subsequently, the second substrate 2 is placed on the first substrate 1 by the robot arm 14 and spin-coated.

The robot arm 14 places the first substrate 1 and the second substrate 2 on the first tray 11, and the UV lamp unit 12 uses resin by using ultraviolet rays through the movement of the tray. After bonding the first and second substrates 1 and 2 by curing the substrate, the fully bonded substrate is stored in the bonded substrate storage unit 13 by the robot arm 14 via the second tray 11a.

At this time, the control of the robot arm 14 is controlled by the device control unit 15.

As the adhesive 5 of the optical disk substrate, a liquid ultraviolet curable resin is mainly used, and a monomer which is a photoinitiator or a photopolymerization (curing) object in order to satisfy appropriate curing conditions, refractive index, viscosity, surface tension, curing shrinkage ratio, etc. ), Low molecular weight (oligomer), and other additives (additives) and a variety of compositions.

The biggest problem which arises in the process of bonding the said 1st, 2nd board | substrate using such a liquid ultraviolet curable resin is a bubble generation | occurrence | production, when the bubble contains in the adhesive agent itself, the 1st board | substrate with which the adhesive agent 5 was apply | coated (1) When the second substrate (2) is deposited on the substrate unevenly, the air that can not escape to the outside is trapped, the case is generated by the dust on the substrate due to static electricity, and the stacked substrate When moving to harden, there are various causes such as mixing when a gap is opened between the substrate and the substrate.

The bubbles thus generated not only cause appearance problems, but also weaken the adhesive strength of the generated portion, refraction of light by refracting light while reading signals from the pit or recording mark where the bubbles are located, and thereby prevent reproduction.

In order to solve the problem of bubbles generated during the bonding process of the substrate, improvement of facilities such as selecting an adhesive having an appropriate viscosity and surface tension, moving the first and second substrates to the hardened part, etc. This is mainly the situation.

In the case of lowering the viscosity of the double adhesive can be the most effective research on low viscosity adhesives have been made.

However, the manufacturing method by the optical disk bonding according to the prior art described above has the following problems.

First, when increasing the content of the monomer to lower the viscosity, it is difficult to cure in a short time due to the slow photopolymerization (cure) rate, and the photopolymerization rate and crosslinking point by using a monomer with a large number of reactors that can increase the content of the photoinitiator or occur Even if the density of the crosslinked point is increased, it is difficult to control the refractive index according to the increase of the photoinitiator, the weakening of the bonding strength due to the low molecular weight, and the development of the monomer requires a lot of time and time.

Second, if the viscosity is too low, adhesives protruding from the outer periphery of the substrate in the spin-coating method may stick to the disk surface, causing problems not only in appearance but also in signal reproduction, and in the case of screen printing, in and around the first substrate. Housewife gets dirty

Third, it is difficult to develop an adhesive for controlling the viscosity of the adhesive, and to select and test the adhesive having a suitable viscosity for the bonding equipment, which also requires a lot of time and difficulty, and it is more difficult to maintain a suitable viscosity for each process.

Therefore, the present invention has been made to solve the above problems, by adjusting the viscosity of the substrate adhesive used in the optical disk bonding method of the spin-coating and screen printing substrate bonding method through a simple temperature control unit, a separate adhesive It is an object of the present invention to provide a method for solving a bubble generation problem and optimizing bonding conditions without a change in composition.

Features of the manufacturing method by the optical disk bonding according to the present invention for achieving the above object, the viscosity control step of adjusting the viscosity of the adhesive by changing the temperature of the adhesive, and a certain amount of viscosity adjusted on the first substrate An adhesive applying step of applying an adhesive, a substrate placing step of placing a second substrate on the first substrate, and an adhesive step of curing and bonding an adhesive having a changed viscosity between the first substrate and the second substrate. To lose.

The action according to the characteristics of the present invention is the development and selection of a separate adhesive by adding a device that can arbitrarily control the viscosity of the substrate adhesive used in the spin-coating and screen-printed substrate bonding method of the optical disk bonding technology You can reduce the cost and time lost of testing and further optimize the viscosity conditions in each process.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Referring to the accompanying drawings, a preferred embodiment of a manufacturing method by optical disk bonding according to the present invention will be described.

Figure 4 shows an embodiment of the adhesive viscosity changes with temperature, the viscosity is a measure of resistance to deformation or flow due to external forces, low viscosity material is easily deformed to flow well Have

And in the case of the adhesive, such a viscosity is exponentially lower as the temperature increases as shown in FIG. 4, so that the desired viscosity can be obtained by installing the temperature controller of the adhesive in the substrate bonding.

Figure 5 (a) is a schematic view of the spin-coated joint according to the present invention, Figure 5 (a) First, the robot arm 14 puts the first substrate 1 on the spin-coating portion 10 .

When the first substrate 1 is placed on the spin-coating portion 10, the dispenser 3 approaches the first substrate 1 and receives the adhesive 5 from the adhesive storage container 3a.

At this time, the temperature controller 16 is installed in the inlet pipe 18a or the dispenser 3 itself through which the adhesive 5 flows from the adhesive storage container 3a to the dispenser 3.

And the viscosity of the adhesive 5 is adjusted by changing the temperature of the adhesive 5 supplied from the adhesive storage container 3a through the temperature adjusting unit 16.

The adhesive 5 with the changed viscosity is then applied to the first substrate 1.

Then, the second substrate 2 is placed on the first substrate 1 by the robot arm 14 and spin-coated.

Subsequently, the spin-coated first and second substrates 1 and 2 are placed on the first tray 11 by the robot arm 14, and the UV lamp unit 12 uses resin by using ultraviolet rays through movement of the tray. By hardening, the first and second substrates 1 and 2 are bonded to each other, and then the fully bonded substrates are stored in the bonded substrate storage part 13 by the robot arm 14 via the second tray 11a. .

Figure 5 (b) is a first embodiment when the temperature control unit is installed in the inlet pipe in Figure 5 (a), Figure 5 (c) is a second embodiment when the temperature control unit is installed in the dispenser in Figure 5 (a) Yes it is.

First, as shown in (b) and (c) of FIG. 5, a temperature change feedback system from the thermocouple 20 is provided to control the temperature of the adhesive through media temperature control such as water or silicone oil, or By adjusting the current or voltage applied to the dispenser 3 or the dispenser 3, the temperature of the adhesive 5 is controlled by adjusting the resistance of the heating band 18b wound around the inlet pipe 18a made of a material having good thermal conductivity. By adjusting the viscosity of the adhesive (5).

Thus, when the temperature control part 16 is installed in the inflow pipe 18a and the dispenser 3, power loss is less than the case where the temperature control part 16 is installed in the adhesive storage container 3a of large capacity, and vaporization is carried out. Environmental pollution and safety problems caused by these adhesives can also be reduced.

6 is a block diagram of a screen printing machine according to the present invention. Referring to FIG. 6 (a), a booth surrounding a screen plate 8, an adhesive press 9, and the like is installed and heated at an upper end thereof. This is the case where the temperature in the booth is adjusted using the part 21.

6 (b) shows a case in which the temperature controller 16 is installed in the adhesive press 9 to directly control the temperature of the surface of the adhesive press 9.

As such, when the temperature controller 16 is installed, if the adhesive meets the curing condition of the UV lamp 12, the spin-coating is controlled by adjusting the viscosity of the adhesive below the flash point represented in FIG. 4. In the case of joining, there are few bubbles generated between the first and second substrates 1 and 2, and have a condition having excellent adhesion while having a uniform thickness and a fast cycle time.

In addition, in the case of screen-printed bonding, it is possible to easily solve the problem of the appearance of the disk when it is loaded by adjusting the temperature in the booth by reducing the occurrence of air bubbles coming out of the screen and increasing the viscosity lowered momentarily after application. have.

This viscosity control method also allows for shorter cycle times by reducing the time to reach lower rpm and maximum rpm for spin-coated joints, which typically require high speed rotations of up to 3500 to 5000 rpm. condition can be found.

Figure 7 shows an embodiment of the effect according to the manufacturing method by the optical disk bonding according to the present invention, Figure 7 (a) is a shortening and continuous reduction of the bonding time including the adhesive coating, deposition, rotation time compared to the conventional method The result was a decrease in the number of bubbles generated in the 100 bonded disks.

7 (b) shows the difference in the tangential tilt of two substrates bonded at the same bonding time.

As described above, despite the shortening of the bonding time, the tilt relative to the bonding time is also improved.

In addition, the conventional bonding method requires a bonding time of at least 7.5 seconds to obtain the same result as the effect of the present invention.

Therefore, in the case of joining according to the present invention, various effects for improving productivity, such as shortening of an overall cycle time, appearance problems, and tilt, may be obtained.

On the other hand, in the case of the spin-coated jointer, the viscosity lowered until just before the adhesive is applied to the cold substrate is rapidly increased, so that a booth is installed in the substrate storage 17 of FIG. 5 to control the temperature of the substrate together. By doing so, the efficiency of viscosity control can be maximized.

The manufacturing method by optical disk bonding according to the present invention as described above has the following effects.

First, by adding a device that can arbitrarily adjust the viscosity of the substrate adhesive, it is possible to reduce the cost and time lost of developing, selecting, and testing a separate adhesive, and to easily find the viscosity condition required for each process.

Second, it is possible to prevent bubble problems that may occur during bonding and product defects that the adhesive liquid is protruded.                     

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (8)

A viscosity adjusting step of controlling the viscosity of the adhesive by changing the temperature of the adhesive in the adhesive applying means; An adhesive coating step of applying the adhesive whose viscosity is adjusted on a first substrate, A substrate depositing step of depositing a second substrate on the first substrate; And a bonding step of curing and adhering the adhesive whose viscosity is changed between the first substrate and the second substrate. The method of claim 1, In the viscosity adjustment step, The method of manufacturing an optical disc, characterized in that for controlling the temperature of the adhesive in the adhesive applying means using water or silicone oil. The method of claim 1, In the viscosity adjustment step, And controlling the temperature of the adhesive by controlling the resistance of the heating band around the adhesive applying means. The method of claim 1, In the viscosity adjustment step, And adjusting the temperature of the adhesive in at least one of a dispenser for applying the adhesive to the first substrate and an inlet tube for supplying the adhesive in the adhesive storage container to the dispenser. The method of claim 1, Determining an adhesive temperature in the adhesive applying means; And heating the adhesive applying means according to the determined temperature. Adhesive applying means for applying a viscosity-adjusted adhesive to a substrate; Heating means for heating the adhesive applying means to adjust the viscosity of the adhesive; And a temperature control unit for determining the adhesive temperature in the adhesive applying means and adjusting the heating temperature of the adhesive applying means according to the determination result. The method of claim 6, The heating means is an optical disc manufacturing apparatus, characterized in that the heating band. The method of claim 6, The adhesive applying means, A storage container for storing the adhesive; A dispenser for applying the adhesive to the substrate; And an inlet pipe for supplying the adhesive in the light keeping container to the dispenser.

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