JP3950319B2 - Method for cleaning glass substrate for information recording medium, method for producing glass substrate for information recording medium, and method for producing information recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to cleaning of a glass substrate for an information recording medium used for an information recording medium such as a magnetic disk, a magneto-optical disk, an optical disk, etc., which is a magnetic recording medium of an information recording apparatus such as a hard disk.Methodas well asMethod for producing glass substrate for information recording mediumThe present invention also relates to a method for manufacturing an information recording medium.
[0002]
[Prior art]
Conventionally, a glass substrate for an information recording medium as described above is formed by cutting a sheet-like glass base plate into a disc shape and polishing the surface thereof, and then chemically strengthening it. In this chemical strengthening, a glass base plate is immersed in a heated chemical strengthening treatment solution, and monovalent metal ions contained in the glass base plate are replaced with monovalent metal ions having a larger ion radius than this. In this way, the strength of the obtained glass substrate is increased. The surface of the glass substrate after chemical strengthening is replaced, and a molten salt generated by monovalent metal ions released to the outside adheres as deposits. In addition to this, fine particles such as metal particles, dust, abrasives, and abrasive powders that form a chemical strengthening treatment device or the like mixed in the molten salt are attached as deposits. In order to remove these deposits, the glass substrate after chemical strengthening is subjected to a cleaning process.
[0003]
A cleaning apparatus for performing a cleaning process on a glass substrate includes a cleaning tank having a substantially square box shape with an upper surface opened. In this cleaning tank, water is stored as a cleaning liquid for cleaning the glass substrate, and the glass substrate after the chemical strengthening treatment is immersed in the water in the cleaning tank. A heater is attached to the inside or outside of the washing tank, and water stored in the washing tank is heated by this heater to become hot water of 30 to 100 ° C. In addition, an ultrasonic generator is attached inside the cleaning tank so as to irradiate the glass substrate immersed in water with ultrasonic waves.
[0004]
Now, the glass substrate after the chemical strengthening treatment is taken out from the chemical strengthening treatment apparatus and then cooled to about room temperature. At this time, the molten salt precipitates on the surface of the glass substrate and adheres as a deposit. The glass substrate with the deposits attached to the surface is first put into a cleaning tank and immersed in warm water at 30 to 100 ° C. Then, an ultrasonic wave is irradiated to the glass substrate immersed in warm water from an ultrasonic generator. Then, the deposits on the surface of the glass substrate are pulverized into fine particles by a physical external force called vibration caused by ultrasonic waves, released from the surface of the glass substrate, and dissolved and removed in the warm water by the polarity and thermal energy of the warm water. It has become so.
[0005]
[Problems to be solved by the invention]
However, when a glass substrate is cleaned using the above-described conventional cleaning apparatus, the ultrasonic wave has a function to vibrate and crush the target deposit, but this ultrasonic vibration stirs the hot water in the cleaning tank. I can't do it. For this reason, in particular, the molten salt among the crushed deposits is not uniformly dispersed in the cleaning tank, but is dispersed and dissolved only in the vicinity of the glass substrate, and the dissolution rate of the molten salt in hot water is rapidly increased. However, there is a problem that it becomes impossible to maintain a sufficient cleaning ability.
[0006]
Furthermore, the deposits contain not only molten salts but also those that are not soluble in warm water, such as the fine particles listed above. Such deposits that do not dissolve in warm water are dispersed in the vicinity of the glass substrate while the ultrasonic wave is applied, but if the ultrasonic wave irradiation is stopped, the adhering substance may be attached again to the surface of the glass substrate. Then, due to such reattached deposits, the cleanliness of the surface of the glass substrate is reduced, fine protrusions are formed, smoothness is lost, and defects are generated.
[0007]
Further, when the distance from the ultrasonic generator becomes long or the number of objects increases, the ultrasonic force weakens the force for vibrating the object. For this reason, there has been a problem that, when the amount of processing of the glass substrate per operation is increased with ultrasonic waves, the adhered matter adhering to the glass substrate cannot be sufficiently removed.
[0008]
  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to disperse or dissolve the deposits uniformly in the entire cleaning liquid stored in the cleaning tank to maintain sufficient cleaning ability, and to prevent the deposits from reattaching. Cleaning glass substrates for information recording media that can improve throughput per workMethodas well asMethod for producing glass substrate for information recording mediumAnother object is to provide a method for manufacturing an information recording medium.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the glass substrate for an information recording medium according to claim 1 is cleaned.MethodThe invention ofAfter immersion and chemical strengthening treatmentDisc-shaped glass substrateWhereasFor cleaning and removing deposits adhering to the surface of the glass substrateApply cleaning treatmentCleaning glass substrates for information recording mediaMethodBecauseHas an opening,A cleaning liquid for reducing the affinity of deposits on the surface of the glass substrate is stored inside, a cleaning tank for storing the glass substrate in the cleaning liquid in a state immersed therein, and the cleaning tankWithinGas supply for generating bubbles in the cleaning liquid that is installed and releases gas in the cleaning tankUsing a cleaning device with holes,Bubbles are generated in the cleaning solution with the glass substrate immersed in the cleaning solution.LetThe bubbles move through the cleaning solution and agitate the cleaning solution to contact the surface of the glass substrate and remove the deposits.Apply cleaning treatmentIt is characterized by this.
[0010]
  Cleaning the glass substrate for information recording media according to claim 2MethodIn the invention of claim 1, in the cleaning tank, the cleaning tank is provided with an inlet and an outlet for the cleaning liquid, the inlet and the outlet are connected by a circulation pipe, and the pump is connected to the circulation pipe. The cleaning liquid in the cleaning tank is sucked from the outlet and returned to the cleaning tank from the inlet through the circulation pipe, and a heater is connected to the circulation pipe. The flowing cleaning liquid is heated and returned to the cleaning tank.
[0011]
  Cleaning the glass substrate for information recording media according to claim 3MethodThe invention according to claim 2 is characterized in that, in the invention according to claim 2, a filter is connected to the circulation pipe, and fine particles having a particle diameter of a certain size or more existing in the cleaning liquid returned to the cleaning tank by the filter are removed. It is what.
[0012]
  Cleaning the glass substrate for information recording media according to claim 4MethodIn the invention according to any one of claims 1 to 3, the bubble has a diameter of 1 to 40 mm.
  The glass substrate for an information recording medium according to claim 5.ProductionThe invention of the method isA chemical strengthening treatment step for chemical strengthening by immersing a disk-shaped glass substrate in a heated chemical strengthening treatment solution, and an adherent adhering to the surface of the glass substrate after the chemical strengthening treatment step. A method for producing a glass substrate for an information recording medium, comprising a cleaning step for cleaning and removing, wherein the cleaning step has an opening, and the inside has an affinity for the deposit on the surface of the glass substrate. The cleaning liquid to be reduced is stored, and the glass tank is immersed in the cleaning liquid, the cleaning tank for storing the glass substrate therein, the cleaning tank is disposed in the cleaning tank, and the gas is discharged and stored in the cleaning tank. Using a cleaning device having a gas supply hole for generating bubbles in the cleaning liquid, generating bubbles in the cleaning liquid in a state where the glass substrate is immersed in the cleaning liquid, and moving the bubbles through the cleaning liquid Stir the cleaning solution Conducted to remove deposits in contact with the surface of the reluctant glass substrateIt is characterized by this.
  The information recording medium according to claim 6.Body productionThe invention of the method isA step of providing at least a magnetic layer on the glass substrate for an information recording medium obtained by the production method according to claim 5.It is characterized by.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The glass substrate of the embodiment is formed in a disk shape having a circular hole at the center thereof by cutting a sheet-shaped glass base plate using a cemented carbide or diamond cutter. Examples of the material of the glass base plate include soda lime glass, aluminosilicate glass, borosilicate glass, and crystallized glass produced by a float method, a downdraw method, a redraw method, or a press method. For example, an information recording medium such as a magnetic disk, a magneto-optical disk, or an optical disk is manufactured by providing an underlayer, a magnetic layer, a protective layer, a lubricating layer, and the like for improving magnetic characteristics on the surface of the glass substrate. . In order to satisfy the impact resistance, vibration resistance, heat resistance, etc. required when the information recording medium is used, the glass substrate is subjected to a chemical strengthening treatment.
[0014]
This chemical strengthening treatment is performed by immersing the glass substrate in a heated chemical strengthening treatment solution. Examples of the chemical strengthening treatment liquid include a potassium nitrate solution, a sodium nitrate solution, silver nitrate, etc., each alone or a mixture of two or more. The temperature of the chemical strengthening treatment liquid is preferably about 50 to 150 ° C. lower than the strain point of the glass material forming the glass substrate. More preferably, it is about 350-400 degreeC. The glass substrate immersed in the heated chemical strengthening solution replaces monovalent metal ions such as lithium and sodium contained in the composition with monovalent metal ions such as potassium, which has a larger ion radius than this. It has been. In this state, compressive stress acts on the surface of the glass substrate, and the glass substrate is chemically strengthened.
[0015]
On the surface of the glass substrate after the chemical strengthening treatment, a molten salt is attached as a deposit. In addition, fine particles such as metal particles, dust, abrasives, and abrasive powder forming the chemical strengthening apparatus by mixing with the molten salt also adhere to the surface of the glass substrate as deposits. In order to remove these deposits, the glass substrate is subjected to a cleaning process using a cleaning device.
[0016]
Next, the cleaning apparatus will be described.
FIG. 1 is a front sectional view of a cleaning apparatus for performing a cleaning process on a glass substrate, FIG. 2 is a side sectional view of the cleaning apparatus, and FIG. 3 is a plan view of the cleaning apparatus as viewed from above. The cleaning tank 11 constituting the cleaning device is formed in a substantially square box shape having an opening 11a on the upper surface. A drain pipe 27 is connected to the bottom wall of the cleaning tank 11 at the center and one corner from below. In addition, valves (not shown) are connected to the drain pipes 27, and each drain pipe 27 can be opened and closed by operating the valves.
[0017]
A water supply pipe 12 is laid from the inner surface of one side wall on the right side in FIG. A water supply pipe 14 having a valve 13 is connected to the proximal end portion of the water supply pipe 12, and the cleaning liquid is supplied from the water supply pipe 14 to the water supply pipe 12 by opening the valve 13. The cleaning liquid in the water supply pipe 12 is discharged from the distal end portion 12 a of the water supply pipe 12 and stored in the cleaning tank 11.
[0018]
A plurality of glass substrates 31 are accommodated in a holder 32 in a state of being vertically arranged at regular intervals, and the holder 32 and the entire holder 32 are accommodated in a cage 33. The glass substrate 31 is immersed in the cleaning liquid stored in the cleaning tank 11 together with the holder 32 and the cage 33 by inserting the cage 33 into the opening 11 a of the cleaning tank 11.
[0019]
The deposits made of the molten salt, fine particles and the like mentioned above are adhered to the surface of the glass substrate 31 by affinity such as ionic bond, intermolecular force, electrostatic force, Coulomb force and the like. The cleaning liquid reduces the affinity of the deposit by dissolving the deposit in the cleaning liquid, or entering between the surface of the glass substrate 31 to lift the deposit from the surface of the glass substrate 31. And released from the surface of the glass substrate 31. In addition, it is possible to dissolve the molten salt, which is an adhering substance, in this cleaning liquid, and water that is easily available without affecting the glass substrate 31 because it is neutral.
[0020]
Normal water may be used as this water, but it is preferable to use filtered pure water, ion-exchanged water, ultrapure water, or the like in order to prevent fine particles from adhering to the glass substrate 31. In addition, if it does not affect the surface of the glass substrate 31, an alcohol such as isopropyl alcohol (IPA), methanol, ethanol, butanol, a cationic, anionic or nonionic surfactant is mixed with this water. May be.
[0021]
An overflow portion 15 is projected from the upper end portion of the rear wall of the cleaning tank 11 on the left side in FIG. 2 so as to extend in the lateral direction. A drain pipe 16 is connected to the lower surface of the overflow portion 15. The water discharged from the front end portion 12a of the water supply pipe 12 into the cleaning tank 11 overflows into the overflow section 15 while filling the cleaning tank 11, and is drained from the drain pipe 16 to the outside.
[0022]
A plurality of gas supply pipes 17 extending from the outside are laid on the inner bottom surface of the cleaning tank 11. A plurality of holes 17 a are formed in the peripheral wall of each gas supply pipe 17. A pump (not shown) is connected to the gas supply pipe 17 outside the cleaning tank 11, and gas is supplied to the inside thereof. Air that does not affect the glass substrate 31 and is easily available is used for this gas. In addition to air, an inert gas such as helium gas, neon gas, or argon gas may be used. Then, when the air supplied to the gas supply pipe 17 is released into the cleaning tank 11 from the hole 17a, bubbles are generated in the water stored in the cleaning tank 11.
[0023]
Bubbles generated from the holes 17a of the gas supply pipe 17 try to move in the water stored in the washing tank 11 from here toward the water surface. When the bubbles come into contact with the glass substrate 31 accommodated in the holder 32 in the cage 33, the affinity of the deposit on the surface of the glass substrate 31 is reduced or eliminated.
[0024]
That is, the adhering substance has a reduced affinity for the surface of the glass substrate 31 when immersed in water. When bubbles come into contact with the surface of the glass substrate 31 in this state, there is a physical external force to such an extent that deposits such as impact generated by the bubbles bursting into fine bubbles or being crushed are released. It is applied to the surface of the glass substrate 31 and the deposits are removed. Further, since the water pressure decreases as it approaches the water surface, the foam pushes up the water while expanding its diameter, and stirs and moves the water in the washing tank 11 by stirring.
[0025]
The amount of air supplied into the gas supply pipe 17 is 30,000 to 110,000 cm per minute.^ThreeIt is preferable that Air supply per minute is 30,000cm^ThreeIf there is less, there is a possibility that bubbles are not sufficiently generated in the water, 110,000 cm^ThreeIn the case where the amount is larger, the glass substrate 31 vibrates greatly due to the momentum when the bubbles come into contact, and there is a possibility that defects such as fine scratches, cracks, and breakage may occur.
[0026]
The bubble preferably has a diameter of 1 to 40 mm by adjusting the diameter of the hole 17 a of the gas supply pipe 17. When the diameter of the foam is less than 1 mm, the adhered substance cannot be sufficiently released and the water cannot be sufficiently stirred. Moreover, when the diameter of a bubble is larger than 40 mm, the glass substrate 31 will vibrate greatly by contact of a bubble, and there exists a possibility that a fine crack, a crack, damage, etc. may arise.
[0027]
In addition, a filter (not shown) is connected to the gas supply pipe 17 outside the cleaning tank 11. Fine particles with a particle size of a certain size or more are removed from the air that has passed through the filter. When bubbles come into contact with the glass substrate 31 immersed in water in the cleaning tank 11, the fine particles mixed in the bubbles are glass. The adhesion to the substrate 31 is prevented.
[0028]
The particle diameter of the fine particles removed from the air by the filter is preferably 0.3 μm or more. When trying to remove fine particles of less than 0.3 μm with a filter, the filter is clogged and resistance increases, and there is a possibility that air cannot be sufficiently fed into the gas supply pipe 17. The upper limit of the particle size of the fine particles is not particularly specified, but is usually 100 μm or less. Since most of the fine particles larger than 100 μm float on the water surface, they can be removed only by immersing the glass substrate 31 in water.
[0029]
An outlet 19 is formed through the lower end of one side wall of the cleaning tank 11, and an outflow pipe 20 is connected to the outside of the cleaning tank 11 beyond the outlet 19. An inflow pipe 21 is disposed at the upper end of the other side wall of the cleaning tank 11, and the lower end of the inflow pipe 21 is opened as an inflow port 22. The outflow pipe 20 and the inflow pipe 21 are connected by a circulation pipe 23. Further, a pump 24 is connected to the circulation pipe 23. Then, the water in the cleaning tank 11 is sucked out of the outflow pipe 20 by the pump 24, reaches the inflow pipe 21 through the circulation pipe 23, and is returned from the inflow pipe 21 into the cleaning tank 11. And the circulation pipe 23 are circulated.
[0030]
A filter 25 is connected in the middle of the circulation pipe 23. The filter 25 is insoluble in water such as metal particles, dust, abrasives, and abrasive powders existing in the water flowing in the circulation pipe 23, and functions to remove fine particles having a certain particle size or more. ing. And the cleanliness of the water returned to the washing tank 11 is maintained favorably by removing fine particles having a particle diameter of a certain size or more with the filter 25. At this time, the particle diameter of the fine particles removed by the filter 25 is preferably 0.2 μm or more. When trying to remove fine particles of less than 0.2 μm with the filter 25, the filter 25 is clogged in the circulation pipe 23, the resistance increases, and water may not flow easily. The upper limit of the particle size of the fine particles is not particularly specified, but is usually 100 μm or less. Since most of the fine particles larger than 100 μm float on the water surface, they can be removed only by immersing the glass substrate 31 in water.
[0031]
Further, a heater 26 is connected to the circulation pipe 23 so as to be positioned closer to the inflow pipe 21 than the filter 25. The heater 26 functions to return warm water having a predetermined temperature from the inflow pipe 21 into the cleaning tank 11 by heating water flowing in the circulation pipe 23. And by circulating water between the washing tank 11 and the circulation piping 23 while heating with the heater 26, the water stored in the washing tank 11 becomes warm water maintained at a constant temperature, and the glass substrate 31 is fixed. It is configured to be washed with warm water for a period of time. Further, the glass substrate 31 that has been washed with warm water for a certain period of time is stopped by heating by the heater 26, and water is supplied from the water supply pipe 12, and the water in the washing tank 11 is replaced, so that the glass substrate 31 is gradually cooled. It has become.
[0032]
The temperature of the warm water is preferably 20 to 70 ° C. When the temperature is less than 20 ° C., the molten salt is difficult to dissolve and the washing ability may be reduced. When the temperature is higher than 70 ° C., water tends to evaporate, and the dissolved molten salt may be precipitated again. Moreover, it is preferable that the time which wash | cleans the glass substrate 31 with warm water is 30 to 60 minutes. If the time for washing with warm water is less than 30 minutes, the deposits cannot be removed sufficiently, and even if washed with warm water for longer than 60 minutes, the cleanliness of the glass substrate 31 does not increase, but the processing amount per work is on the contrary. Decrease.
[0033]
The amount of water circulated by the pump 24 during washing with warm water is adjusted by the capacity of the washing tank 11 and the washing time with warm water, and all the water in the washing tank 11 circulates 1 to 5 times during the washing time with warm water. It is preferable to set so as to. Specifically, the circulation rate per minute is preferably set to 1/20 to 1/10 of the capacity of the washing tank 11. For example, the capacity of the washing tank 11 is 1.015 m^Three, Washing time with warm water is 40 minutes, 1.015m in 40 minutes^ThreeWhen the water is circulated 2.4 times, the circulation rate per minute is 1/17 of the capacity of the washing tank 11 0.06 m^ThreeIt becomes.
[0034]
When the number of times of water circulation during the washing time with hot water is less than one, a large amount of fine particles are mixed in the water, and the washing ability cannot be sufficiently maintained. The cleanliness of 31 does not increase, but on the contrary, the throughput per work decreases. In addition, if the circulation rate per minute is less than 1/20 of the capacity of the washing tank 11, the water may not be sufficiently heated, and sufficient washing ability may not be exhibited. However, the cleanliness of the glass substrate 31 does not increase, but the processing amount per operation decreases.
[0035]
Next, the operation of the cleaning device will be described.
When the cleaning apparatus as shown in FIGS. 1 to 3 is used, the valve 13 is opened in a state where the two drain pipes 27 are closed in advance, and the cleaning tank 11 is supplied from the water supply pipe 14 through the water supply pipe 12. Water is supplied. This water supply is continued until the water overflows from the overflow part 15, and then the valve 13 is closed and water is stored in the cleaning tank 11. Thereafter, the pump 24 is operated, and the water in the cleaning tank 11 is circulated while heating the water with the heater 26, and the water in the cleaning tank 11 is heated and maintained at 20 to 70 ° C.
[0036]
In this state, the glass substrate 31 together with the holder 32 and the cage 33 is put into the cleaning tank 11 and immersed in warm water. Then, after the glass substrate 31 is immersed in warm water, air is supplied to the gas supply pipe 17 while circulating the warm water, and air is discharged from the holes 17a to generate bubbles in the warm water.
[0037]
Bubbles generated in the warm water move toward the water surface as it is while stirring the warm water. At this time, bubbles are brought into contact with the glass substrate 31. The bubbles in contact with the glass substrate 31 are physically immersed in warm water to give a physical external force to the deposit with reduced affinity for the surface of the glass substrate 31. Then, due to the physical external force, the affinity of the deposit on the surface of the glass substrate 31 disappears, and the deposit is released from the surface of the glass substrate 31. Of the adhered matter released, the molten salt is dissolved in the warm water as it is, and the fine particles are taken into the foam or dispersed in the warm water.
[0038]
On the surface of the glass substrate 31, the hot water in which the molten salt is dissolved is pushed up from the surface of the glass substrate 31 toward the water surface along with the movement of the bubbles, so that liquid exchange is always performed. Further, when the hot water in which the molten salt is dissolved reaches the water surface, it is uniformly diffused into the hot water in the washing tank 11 as it is. For this reason, there is no great difference in the solubility of the molten salt in the warm water between the vicinity of the glass substrate 31 and other locations, and the solubility of the molten salt is uniform throughout the warm water in the cleaning tank 11, and the cleaning ability is Well maintained.
[0039]
The hot water in which the fine particles are dispersed is pushed up from the surface of the glass substrate 31 toward the water surface along with the movement of the bubbles in the same manner as the hot water in which the molten salt is dissolved. To be distributed. Further, among the fine particles uniformly dispersed in the warm water, those having a particle size of 0.3 μm or more are removed by the filter 25 when the warm water flows through the circulation pipe 23 and reattached to the surface of the glass substrate 31. Is prevented.
[0040]
After the glass substrate 31 is washed with warm water for a certain period of time, the heating of the water by the heater 26 is stopped, the circulation by the pump 24 and the release of the air from the gas supply pipe 17 are continued, and the water at room temperature is supplied from the water supply pipe 12. Is supplied with water. Then, in the hot water, the molten salt is dissolved and the fine particles are still dispersed, and most of the warm water overflows from the overflow portion 15 and is drained from the cleaning tank 11 to the outside. Thereafter, the glass substrate 31 is gradually cooled until the hot water in the cleaning tank 11 is replaced with water at room temperature. Then, after the glass substrate 31 is gradually cooled, water supply from the water supply pipe 12, circulation by the pump 24, and release of air from the gas supply pipe 17 are stopped, and the glass substrate 31 is pulled up together with the cage 33 from the cleaning tank 11. And transported to the next process. Further, the water in the cleaning tank 11 is drained by opening both drain pipes 27 after the glass substrate 31 is pulled up from the cleaning tank 11.
[0041]
The effects exhibited by the above embodiment will be described below.
-According to the cleaning device of the embodiment, bubbles are generated in the water stored in the cleaning tank 11, the water is stirred by the bubbles, and the bubbles are brought into contact with the glass substrate 31 to remove the deposits. . For this reason, it is possible to uniformly disperse or dissolve the deposits in the entire water stored in the cleaning tank 11 to maintain sufficient cleaning ability, and to suppress the reattachment of deposits. Unlike the ultrasonic waves mentioned in the conventional example, the foam spreads uniformly in the entire cleaning tank 11 and is almost certainly in contact with the glass substrate 31, so that there is no residue left behind and the amount of processing per work Can be improved.
[0042]
In addition, by circulating the water stored in the cleaning tank 11 using the pump 24 while being heated by the heater 26, the water in the cleaning tank 11 can be maintained at a constant temperature. The cleaning ability can be maintained well.
[0043]
Furthermore, by connecting the filter to the circulation pipe 23 and removing the fine particles present in the water, it is possible to more effectively suppress the reattachment of the deposit on the glass substrate 31.
[0044]
Furthermore, by setting the diameter of the bubbles to 1 to 40 mm, it is possible to perform better removal of deposits and stirring of water while suppressing damage to the glass substrate 31.
In addition, this embodiment can also be changed and embodied as follows.
[0045]
For example, the gas supply pipes 17 may be laid on the inner surfaces of both side walls of the cleaning tank 11 so that bubbles are brought into contact with the glass substrate 31 from the side in addition to the lower side. When comprised in this way, water can be stirred more efficiently.
[0046]
As long as warm water is stored in the washing tank 11 to some extent, washing may be performed while supplying water from the water supply pipe 12 and heating water circulated by the heater 26. When configured in this manner, since the warm water in which the deposits in the washing tank 11 are dissolved or dispersed by the amount of water supplied from the water supply pipe 12 is drained from the overflow portion 15, the cleanliness of the water in the washing tank 11 Can be increased.
[0047]
The heater 26 may be omitted and hot water may be supplied from the water supply pipe 12.
-You may comprise so that the glass substrate 31 may be irradiated with an ultrasonic wave in the state by which the glass substrate 31 was immersed in the washing | cleaning liquid in the washing tank 11. FIG. When configured in this way, it is possible to pulverize the deposits on the surface of the glass substrate by vibration caused by ultrasonic waves, and with the synergistic effect of ultrasonic waves and bubbles, the surface cleanliness of the glass substrate 31 is improved. It can be.
[0048]
  Furthermore, the technical idea that can be grasped from the embodiment is described below..
[0049]
  5. The cleaning liquid in the cleaning tank is maintained at a constant temperature of 20 to 70 ° C. by heating the cleaning liquid returned to the cleaning tank with the heater. 6. Cleaning glass substrates for information recording mediaMethod. When comprised in this way, the washing | cleaning capability with respect to the deposit | attachment of a washing | cleaning liquid can be maintained favorable.
[0050]
  The glass substrate for an information recording medium according to claim 3 or 4, wherein fine particles having a particle size of 0.2 µm or more are removed by the filter.Method. When configured in this way, it is possible to prevent the fine particles removed and dispersed in the cleaning liquid from reattaching to the glass substrate.
[0051]
  -30,000-110,000 cm per minute in the gas supply pipe³It is characterized by supplying the air ofFeelingCleaning device for glass substrate for recording media. When comprised in this way, sufficient quantity of foam can be generated in a washing | cleaning liquid, suppressing the damage of a glass substrate.
[0052]
  A filter is connected to the gas supply pipe, and the filter removes fine particles having a particle size of 0.3 μm or more from the air supplied to the gas supply pipe.FeelingCleaning device for glass substrate for recording media. When comprised in this way, it can prevent that the microparticles | fine-particles mixed in the air which generate | occur | produces a bubble adhere to a glass substrate.
[0053]
  5. The information recording medium according to claim 2, wherein a circulating amount of the cleaning liquid per minute by the pump is 1/20 to 1/10 of a capacity of the cleaning tank. Glass substrate for cleaningMethod. When comprised in this way, a washing | cleaning liquid can fully exhibit the washing | cleaning capability.
[0054]
【The invention's effect】
  As described in detail above, the present invention has the following effects.
  Cleaning of the glass substrate for information recording media according to claim 1MethodAccording to the invention, it is possible to uniformly disperse or dissolve the deposits in the entire cleaning liquid stored in the cleaning tank and maintain a sufficient cleaning ability, and to suppress the reattachment of deposits, The throughput per work can be improved.
[0055]
  Cleaning the glass substrate for information recording media according to claim 2MethodAccording to the invention, in addition to the effect of the invention of the first aspect, it is possible to satisfactorily maintain the water cleaning ability for the deposit.
[0056]
  Cleaning the glass substrate for information recording media according to claim 3MethodAccording to the invention, in addition to the effect of the invention according to claim 2, it is possible to more effectively suppress the reattachment of the deposit to the glass substrate.
[0057]
  Cleaning the glass substrate for information recording media according to claim 4MethodAccording to the invention, in addition to the effects of the invention according to any one of claims 1 to 3, it is possible to perform better removal of deposits and stirring of water while suppressing damage to the glass substrate. it can.
  The glass substrate for an information recording medium according to claim 5.ProductionAccording to the method invention,In addition to the effects of the first aspect of the invention, it is possible to suitably remove deposits that are attached when the chemical strengthening treatment is performed.
  The information recording medium according to claim 6.Body productionAccording to the method invention,A suitable information recording medium can be obtained.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a cleaning apparatus according to an embodiment.
FIG. 2 is a side sectional view showing the cleaning device of the embodiment.
FIG. 3 is a plan view showing the cleaning apparatus according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Cleaning tank, 11a ... Opening part, 17 ... Gas supply pipe | tube, 19 ... Outlet, 22 ... Inlet, 23 ... Circulation piping, 24 ... Pump, 25 ... Filter, 26 ... Heater, 31 ... Glass substrate.

Claims (6)

It was immersed in a heated chemical strengthening treatment solution to the glass substrate which forms a disc-shaped after having been subjected to chemical strengthening treatment, information for performing a cleaning process for removing by washing the material adhering to the surface of the glass substrate A method for cleaning a glass substrate for a recording medium,
A cleaning liquid that has an opening and stores therein a cleaning liquid that reduces the affinity of deposits with respect to the surface of the glass substrate, and is stored in the cleaning liquid in a state where the glass substrate is immersed in the cleaning liquid; Using a cleaning device that is disposed in the cleaning tank and has a gas supply hole for generating bubbles in the cleaning liquid that is released and stored in the cleaning tank ,
The cleaning solution is generated bubbles in the washing liquid in a state where the glass substrate is immersed in, so as to remove deposits in the bubbles in contact with the surface of the glass substrate while stirring the cleaning liquid moves through the washing liquid A method for cleaning a glass substrate for an information recording medium, comprising performing a cleaning process . The cleaning tank is provided with an inlet and an outlet for the cleaning liquid, the inlet and the outlet are connected by a circulation pipe, and a pump is connected to the circulation pipe so that the cleaning liquid in the cleaning tank is supplied from the outlet. Suction and return to the washing tank from the inlet through the circulation pipe, and a heater is connected to the circulation pipe so that the cleaning liquid flowing in the circulation pipe is heated by the heater and returned to the washing tank. The method for cleaning a glass substrate for an information recording medium according to claim 1, comprising : 3. The glass for an information recording medium according to claim 2, wherein a filter is connected to the circulation pipe to remove fine particles having a particle diameter of a certain size or more present in the cleaning liquid returned to the cleaning tank by the filter. Substrate cleaning method . The diameter of the said foam is 1-40 mm, The washing | cleaning method of the glass substrate for information recording media in any one of Claims 1-3 characterized by the above-mentioned. A chemical strengthening treatment step for chemical strengthening by immersing a disk-shaped glass substrate in a heated chemical strengthening treatment solution, and an adherent adhering to the surface of the glass substrate after the chemical strengthening treatment step. A method for producing a glass substrate for an information recording medium comprising a cleaning step for cleaning and removing,
The cleaning step has an opening, and a cleaning liquid that reduces the affinity of the deposit on the surface of the glass substrate is stored therein, and the glass substrate is immersed in the cleaning liquid and accommodated therein. Using a cleaning device provided with a cleaning tank and a gas supply hole for generating bubbles in the cleaning liquid that is disposed in the cleaning tank and releases gas in the cleaning tank,
A bubble is generated in the cleaning liquid in a state where the glass substrate is immersed in the cleaning liquid, and the bubbles move in the cleaning liquid so as to contact the surface of the glass substrate while stirring the cleaning liquid and remove deposits. A method for producing a glass substrate for an information recording medium. A method for producing an information recording medium, comprising a step of providing at least a magnetic layer on the glass substrate for information recording medium obtained by the production method according to claim 5.

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