JP2010267823A - Vapor dryer and vapor drying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a clean dry state wherein there is no stain on a surface of a body to be cleaned without causing a decrease in productivity due to an increase in takt time. <P>SOLUTION: An after-heat drying tank 6 is provided behind an IPA vapor drying tank 2 in which the body 13 to be cleaned which is mounted on a carrying tool 13a is dipped in an IPA vapor atmosphere 4 to be vapor-dried, and the body 13 to be cleaned and the carrying tool 13a which are heated up to predetermined temperature with latent heat in the IPA vapor atmosphere 4 after the vapor drying in the IPA vapor drying tank 2 are carried in the after-heat drying tank 6 to accelerate drying with latent heat that the body 13 to be cleaned and the carrying tool 13a have, thereby surely preventing the body 13 to be cleaned from having a defect such as a stain due to remaining of a droplet on a surface of the body 13 to be cleaned or the carrying tool 13a without requiring a complicated operation such as repetitive immersion in the IPA vapor atmosphere 4 in the IPA vapor drying tank 2 etc. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a steam drying apparatus and a steam drying method.

For example, in a cleaning process of an optical element such as a glass substrate, an optical lens, and an optical filter, the optical element is rinsed with pure water and then the drying process is started.
In many cases, a vapor drying apparatus using an organic solvent is used in this drying process. As an organic solvent, IPA (isopropyl alcohol) is widely used.

  In a steam drying apparatus using IPA, an optical element as an object to be cleaned is carried into a steam tank filled with IPA vapor at a temperature of about 82 ° C., and the IPA vapor is applied to the surface of the optical element at a temperature lower than that of IPA vapor. A process of rinsing the surface of the optical element with the IPA liquid which is condensed and adheres to the surface of the optical element and removes the cleaning liquid or foreign matter remaining on the surface of the optical element by replacing with the IPA liquid is performed.

  The IPA is heated to about 82 ° C. by a heating device provided in the drying tank, and an atmosphere of IPA vapor is formed in the drying tank. When an optical element at room temperature after washing is brought into this IPA vapor atmosphere, the temperature of the optical element is lower than that of the IPA vapor, so that the IPA vapor agglomerates rapidly on the surface of the optical element. The amount of IPA vapor atmosphere decreases, and the IPA vapor atmosphere height decreases.

As a result, it takes some time for the lowered IPA vapor height to return to the original IPA vapor height position. Meanwhile, the condensation of IPA vapor at the surface of the optical element follows.
At this time, the temperature of the optical element rises due to the latent heat released from the condensed IPA vapor.

  Then, when the temperature of the optical element becomes equal to the temperature of the IPA vapor, the condensation of the IPA vapor is stopped, the optical element is pulled up from the IPA vapor atmosphere, and cooled and dried above the IPA vapor atmosphere.

  Such a steam drying apparatus using IPA is already used in a wide field. On the other hand, the shapes of objects to be cleaned such as optical elements and hard disks are diversified, and depending on the shape, there are technical problems such as poor drying and spots such as watermarks on the edges of the objects to be cleaned. It was.

  Therefore, in Patent Document 1, in the disk steam drying apparatus, the disk pulled up to the height of the cooling coil provided above the IPA steam area in the drying tank is lowered again, and the lower end of the disk is moved to the IPA steam. A technique is disclosed that attempts to suppress the occurrence of stains at the lower end of the disk by re-immersing it in the area and pulling it up.

  However, in the technique of the above-mentioned Patent Document 1, the following technical problems occur when applied to a multi-tank type cleaning and drying apparatus in which a cleaning tank and a steam drying tank are arranged in series.

  That is, in a multi-tank type washing and drying apparatus, when processing the object to be cleaned from the washing tank to the steam drying tank while sequentially moving by automatic conveyance, the processing time (tact time) in each of the washing tank and the steam drying tank is Time) must be the same, and the object to be cleaned is transferred to the next process at the same timing.

  For this reason, as in Patent Document 1, when the object to be cleaned is re-immersed in the subsequent steam drying tank, the processing time in the steam drying tank becomes long.

  Therefore, in order to match the operation of the steam drying tank with a long processing time with the takt time of the cleaning tank, it is necessary to install multiple steam drying tanks and perform parallel processing of the steam drying. There was a technical problem that the equipment cost of the washing and drying apparatus would be high.

  In addition, when the cost of equipment is kept down with only one steam drying device, the cleaning time in the steam drying tank is nearly twice as long as the conventional one, and the tact time of the cleaning process is also doubled accordingly. This causes another technical problem that the productivity of the cleaning / drying apparatus is halved.

  Further, as in Patent Document 1, when a part of the disk to be cleaned is partially reimmersed in the IPA vapor, the disk is positioned on the boundary line between the IPA vapor and the upper cooling air. Therefore, there is a concern that the drying quality may deteriorate due to non-uniform drying.

JP 2008-264690 A

  An object of the present invention is to provide a steam drying technique capable of obtaining a clean dry state without a stain on the surface of an object to be cleaned without causing a decrease in productivity due to an increase in tact time.

A first aspect of the present invention is a first treatment tank in which vapor drying of an object to be cleaned by vapor of an organic solvent is performed,
A second treatment tank in which preheat drying of the object to be cleaned that has undergone the steam drying is performed;
A steam drying apparatus comprising:
A second aspect of the present invention is a first step of performing vapor drying of an object to be cleaned using an organic solvent vapor;
A second step of performing preheat drying of the object to be cleaned that has undergone the steam drying;
A steam drying method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the vapor | steam drying technique which can obtain the clean dry state which does not have a spot on the surface of a to-be-washed | cleaned object can be provided, without producing the productivity fall by increase in tact time.

It is a conceptual diagram which shows an example of a structure of the steam drying apparatus which enforces the steam drying method which is one embodiment of this invention. It is a conceptual diagram which shows an example of a structure of the modification of the steam drying apparatus which enforces the steam drying method which is one embodiment of this invention. It is a flowchart which shows an example of an effect | action of the steam drying method which is one embodiment of this invention.

In the first aspect of the present embodiment, an optical element cleaning / drying apparatus using an organic solvent, which includes a steam drying tank and one or more residual heat drying tanks, is exemplified.
In the second aspect of the present embodiment, in the optical element cleaning and drying apparatus described in the first aspect, the preheat drying tank is exemplified by a configuration including a heating device capable of adjusting the temperature.

  In the third aspect of the present embodiment, a steam drying step in which the optical element is steam-dried in a steam drying tank, a step in which the optical element is preheated in a preheat drying tank installed in one or more tanks after the steam drying step, The optical element drying method provided with is illustrated.

In the fourth aspect of the present embodiment, in the optical element cleaning and drying apparatus described in the first aspect, the preheat drying tank is exemplified as a sealed structure.
In the fifth aspect of the present embodiment, in the optical element cleaning and drying apparatus described in the first aspect, a configuration in which a heat insulating material is installed on the lower surface and the side surface of the preheat drying tank is illustrated.

  In the sixth aspect of the present embodiment, in the optical element cleaning and drying apparatus described in the first aspect, a configuration in which a heater is installed in the lower part, the side part, or both of the preheat drying tank is illustrated.

The operation and effect of the first aspect described above is as follows as an example.
In an optical element cleaning / drying apparatus that vapor-drys using an organic solvent, the object to be cleaned is kept warm in the vicinity of the boiling point of the solvent in order to wait for the object to be cleaned in a steam atmosphere in which the organic solvent is heated to become steam. .
However, there is a case where a solvent that has not been completely dried by the steam drying is attached to the object to be cleaned that has come out of the steam tank.

  The reason why the solvent did not dry completely was that the liquid was likely to accumulate in the object to be cleaned and the jig that holds it, or because the heat capacity of the object to be cleaned was large, the object to be cleaned was near the vapor temperature of the solvent. It is thought that it did not dry because it was not heated enough.

  If the solvent that has not been completely dried is slowly dried at room temperature, dirt in the air tends to adhere to the portion where the solvent is accumulated, resulting in generation of spots.

  Therefore, in the optical element cleaning and drying apparatus according to the first aspect of the present embodiment, a preheat drying tank that promotes drying by the residual heat of the object to be cleaned is installed after the steam drying tank, Allowing the object to be cleaned to stand still accelerates the drying of the residual solvent.

  In addition, it is possible to quickly dry before the dirt in the air adheres by accelerating the drying of the residual solvent by installing a residual heat drying tank, and it is possible to prevent the formation of spots on the object to be cleaned. .

The operation and effect of the second aspect described above are as follows as an example.
Also, by providing a heating device capable of adjusting the temperature in the residual heat drying tank, the inside of the residual heat drying tank can be heated, and the amount of heat taken away by the heat of vaporization when the solvent remaining in the object to be cleaned is dried. Can be compensated. As a result, the drying time of the object to be cleaned is further shortened, and a good drying quality free from defects such as spots can be obtained.

The operation and effect of the above-described third aspect is as follows as an example.
By providing the preheat drying process using the preheat drying tank after the steam drying process, the object to be cleaned can be dried quickly and the occurrence of spots on the object to be cleaned can be prevented.

  Moreover, the stationary time in a preheat drying tank can be shortened by using one or more preheat drying tanks in a preheat drying process. Thereby, it is possible to cope with a cleaning machine having a short cleaning tact.

The operation and effect of the above-described fourth aspect is as follows as an example.
By making the preheat drying tank a sealed structure, the preheat drying process is not easily affected by the surrounding environmental conditions, and contamination of the object to be cleaned due to adhesion of foreign matters in the air can be prevented. Moreover, the amount of heat contributing to residual heat drying can be maintained by suppressing the temperature drop of the object to be cleaned.

The operation and effects of the fifth aspect described above are as follows as an example.
By installing a heat insulating material on the lower and side surfaces of the residual heat drying tank, it is possible to suppress the temperature drop of the object to be cleaned, and at the same time, the temperature in the residual heat drying tank with the heat of the object to be cleaned heated in the previous steam drying process. Can be effectively maintained and raised.

The operation and effect of the above-described sixth aspect is as follows as an example.
By installing a heater at the bottom or side of the residual heat drying tank, or both, the temperature in the residual heat drying tank can be maintained at a high level, and at the same time, the temperature in the residual heat drying tank is controlled to a desired value. Therefore, preheat drying can be performed effectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing an example of a configuration of a steam drying apparatus that performs a steam drying method according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating an example of a configuration of a modified example of the steam drying apparatus that performs the steam drying method according to the embodiment of the present invention.
FIG. 3 is a flowchart showing an example of the operation of the steam drying method according to one embodiment of the present invention.

  In this embodiment, in FIGS. 1 and 2, the left-right direction is described as the X direction, the up-down direction as the Z direction, and the direction perpendicular to the paper surface as the Y direction. As an example, the Z direction is the vertical direction, and the XY plane is the horizontal plane.

  As illustrated in FIG. 1, the steam drying apparatus M <b> 1 of the present embodiment includes an IPA steam drying tank 2 (first treatment tank) and a residual heat drying tank 6 (second tank) that are sequentially arranged at the subsequent stage of the IPA immersion tank 1. Treatment tank) and a handling robot 11 for moving an object 13 (object to be cleaned) between these tanks.

  For example, the handling robot 11 includes a path that passes above the IPA immersion tank 1, the IPA steam drying tank 2, and the residual heat drying tank 6, and is a transverse rail that is laid in a loop shape in a horizontal plane (XY plane). 11a and a plurality of carriages 11b that travel so as to circulate along the traverse rail 11a.

  Further, an elevating arm 11c that elevates in the Z direction is provided at the lower part of each carriage 11b, and a conveying jig 13a on which an object to be cleaned 13 is placed is detachable at the lower end of the elevating arm 11c. It has a configuration to be held.

  Then, the carriage 11b is moved and stopped to the position immediately above each of the IPA immersion tank 1, the IPA steam drying tank 2, and the residual heat drying tank 6, and further, is placed on the conveying jig 13a by the lifting and lowering operation of the lifting arm 11c. Transport operations such as loading and unloading of the object to be cleaned 13 into each tank are performed.

  On the other hand, in the steam drying apparatus M1 of the present embodiment, the IPA steam drying tank 2 has a cup shape whose upper end is opened for carrying in and carrying out the object 13 to be cleaned.

  A heater 3 for heating isopropyl alcohol (IPA 15 (organic solvent)) stored in the bottom is provided at the bottom of the IPA vapor drying tank 2. Then, the IPA 15 is heated to a predetermined temperature by the heater 3 and evaporated to form an IPA vapor atmosphere 4 inside the IPA vapor drying tank 2.

  A cooling pipe 5 through which a coolant such as cooling water flows is arranged along the entire circumference at the opening end of the upper part of the IPA vapor drying tank 2, and this cooling pipe is provided inside the IPA vapor drying tank 2. The IPA vapor atmosphere 4 that has risen to the arrangement height of 5 is condensed, and is returned to the IPA 15 at the bottom along the wall surface of the IPA vapor drying tank 2 to be recovered.

Thereby, the height of the IPA vapor atmosphere 4 generated from the IPA 15 at the bottom of the IPA vapor drying tank 2 is kept constant at a predetermined height directly below the cooling pipe 5 inside the IPA vapor drying tank 2.
In the case of the present embodiment, the residual heat drying tank 6 disposed in the subsequent stage of the IPA vapor drying tank 2 is configured as a substantially rectangular parallelepiped sealed container.

  On the upper surface of the residual heat drying tank 6, a carry-in door 14a is provided for the elevating arm 11c of the handling robot 11 holding the carrying jig 13a to enter and exit.

  Further, inside the residual heat drying tank 6, an in-tank belt conveyor 12 for conveying the conveying jig 13 a delivered from the lifting arm 11 c in the horizontal direction (X direction) has a predetermined length in the X direction. Is provided.

  In the case of the present embodiment, the length of the in-tank belt conveyor 12 is set to, for example, a length in which two conveying jigs 13a are simultaneously placed in the conveying direction of the in-tank belt conveyor 12. .

  That is, in the case of the present embodiment, the length and transport speed of the in-tank belt conveyor 12 are the same as the takt time in the previous stage IPA immersion tank 1 and the IPA steam drying tank 2 (one set placed on the transport jig 13a). The to-be-cleaned object 13 placed on the conveying jig 13a moves on the belt conveyor 12 in the tank without being affected by the time required for processing per object to be cleaned 13). It is set to a length and a conveying speed that allow a sufficient amount of time to be preheated and dried.

  A carry-out door 14b is provided on the side wall portion of the preheat drying tank 6 facing the terminal portion in the moving direction of the belt conveyor 12 in the tank, and a high level corresponding to the belt conveyor 12 in the tank is provided outside the carry-out door 14b. The outside tank conveyor 12a is provided at this position.

  And the conveyance jig 13a on which the to-be-washed object 13 that has been preheated and dried while being placed on the belt conveyor 12 in the tank is moved to the side of the belt conveyor 12a outside the tank through the carry-out door 14b and is paid out. .

  A heat insulating material 7 is disposed on the entire wall surface of the remaining heat drying tank 6 to prevent a temperature drop of the object 13 to be cleaned placed on the conveying jig 13a carried into the remaining heat drying tank 6, and the object 13 to be cleaned. In addition, each of the conveying jigs 13a has a structure that is effectively dried by the residual heat of the jig 13a.

  Further, in the case of the present embodiment, an explosion-proof heater 8 (temperature control means) for heating the internal atmosphere of the residual heat drying tank 6 and the internal atmosphere of the residual heat drying tank 6 are provided at the bottom of the residual heat drying tank 6. A temperature sensor 9 (temperature control means) for detecting the temperature is installed.

  And based on the temperature of the residual heat drying tank 6 measured by the temperature sensor 9, the temperature of the residual heat drying tank 6 is controlled by controlling the heater 8 by a temperature adjusting mechanism (not shown) provided in the temperature sensor 9. The structure is maintained at a desired set temperature.

  In addition, for example, a clean unit 10 that forms a clean air curtain at the opening of the carry-in door 14a is installed at a position adjacent to the carry-in door 14a on the upper wall surface of the residual heat drying tank 6 having a sealed structure, and through the carry-in door 14a. It has a structure that prevents dust and the like from entering the preheat drying tank 6.

In addition, the handling robot 11 for transporting the object to be cleaned 13 placed on the transport jig 13a and the in-tank belt conveyor 12 for transporting in the tank inside the residual heat drying tank 6 shake the object to be cleaned 13. In order to prevent damage, a structure with less vibration is adopted.
Hereinafter, an example of the operation of the steam drying apparatus M1 of the present embodiment will be described.

  In FIG. 1, a room temperature object 13 cleaned by a deionized water cleaning facility (not shown) located upstream of the IPA immersion tank 1 in the transfer path of the handling robot 11 is placed on a transfer jig 13 a. Is held by the lifting arm 11c of the handling robot 11, arrives at the IPA immersion tank 1, and is immersed under the liquid surface of the IPA 15 of the IPA immersion tank 1 (step 101 in FIG. 3).

Then, liquid and foreign matters such as pure water adhering to the object to be cleaned 13 and the conveying jig 13 a are replaced with the IPA 15 and removed at the bottom of the IPA immersion tank 1.
Thereafter, the object to be cleaned 13 and the transfer jig 13 a are carried into the next IPA vapor drying tank 2 by the handling robot 11, and the entire object to be cleaned 13 is immersed in the IPA vapor atmosphere 4.

  At this time, due to a temperature difference between the object to be cleaned 13 and the transfer jig 13a and the IPA vapor atmosphere 4 having a temperature of, for example, 82 ° C., the IPA vapor atmosphere 4 causes the surface of the object to be cleaned 13 and the transfer jig 13a. Then, it is condensed as innumerable droplets of IPA 15, and the surfaces of the object 13 and the conveying jig 13a are washed away.

  As a result, moisture and foreign matter remaining on the surfaces of the object to be cleaned 13 and the transfer jig 13a are removed by being replaced by the condensed IPA 15, and the object to be cleaned 13 and the transfer jig 13a are condensed by the IPA. In response to the latent heat of the steam atmosphere 4, it is heated to a temperature substantially equal to that of the IPA steam atmosphere 4 to be in a dry state (step 102 (first step) in FIG. 3).

  In the present embodiment, after being dried as described above, the object to be cleaned 13 and the conveying jig 13a are further carried by the handling robot 11 into the remaining heat drying tank 6 through the carry-in door 14a. Delivered onto the belt conveyor 12.

  Since the remaining heat drying tank 6 is maintained at a predetermined temperature by the heater 8, the object to be cleaned 13 and the transfer jig 13a that are placed on the belt conveyor 12 in the tank and move toward the carry-out door 14b are There is almost no decrease in temperature.

  Then, the object to be cleaned 13 and the conveying jig 13a are quickly dried by the residual heat of the object to be cleaned 13 itself while moving on the belt conveyor 12 in the tank at the predetermined speed toward the carry-out door 14b. Then, even a small drop of IPA 15 remaining on the object to be cleaned 13 or the conveying jig 13a is completely vaporized and removed (step 103 (second step) in FIG. 3).

  The to-be-cleaned object 13 and the conveying jig 13a that have been completely dried by the residual heat drying are discharged to the outside belt conveyor 12a through the discharge door 14b and transferred to the outside.

  As described above, in the present embodiment, after the steam drying by the IPA steam atmosphere 4 in the IPA steam drying tank 2, the preheating drying is further performed in the preheating drying tank 6, so that the object to be cleaned 13 and the conveying jig 13a are It is possible to reliably prevent the liquid droplets and foreign matters that contribute to a stain such as a watermark from being discharged to the outside, and to obtain a clean and dry object 13 that is free from a defect such as a stain. it can.

  Furthermore, in the case of the steam drying apparatus M1 of the present embodiment, in the IPA steam drying tank 2, the object to be cleaned 13 is again immersed in the IPA steam atmosphere 4 after the object 13 to be cleaned in the IPA steam atmosphere 4 is steam dried. This complicated and redundant operation is unnecessary.

  For this reason, for example, in order to match the tact time of the previous IPA immersion tank 1, the number of IPA steam drying tanks 2 is increased to two or more and operated in parallel, or conversely, a single IPA steam drying tank No measures such as increasing the takt time in accordance with the time required for steam drying in 2 are required.

  That is, according to the steam drying apparatus M1 of the present embodiment, without causing disadvantages such as high cost due to an increase in the number of installed IPA steam drying tanks 2 and a decrease in productivity due to an extension of tact time, It is possible to obtain a clean and dry object 13 having no defects.

  Further, in the residual heat drying tank 6, by adjusting the length and moving speed of the belt conveyor 12 in the tank according to the tact time, a sufficient residual heat drying time for the article 13 to be cleaned and the conveying jig 13 a in the residual heat drying tank 6 is obtained. Since it can be twisted out, it is possible to sufficiently dry the pre-heated object 13 and the conveying jig 13a without being affected by the tact time.

Furthermore, by making the preheating drying tank 6 into a sealed structure, the preheating drying process of the article 13 to be cleaned in the preheating drying tank 6 becomes less susceptible to changes in the ambient temperature, etc. It is possible to prevent the object to be cleaned 13 from being stained due to adhesion.
In addition, there is an advantage that the amount of heat contributing to residual heat drying can be maintained by suppressing the temperature drop of the object to be cleaned.

Next, with reference to FIG. 2, the modification of the steam-drying apparatus which implements the steam-drying method of this Embodiment is demonstrated.
In the steam drying apparatus M2 of the modified example illustrated in FIG. 2, the structure of the residual heat drying tank 16 is different from the residual heat drying tank 6 of the steam drying apparatus M1 described above.

  That is, in this steam drying apparatus M2, the residual heat drying tank 16 is configured by a rectangular parallelepiped open container whose upper side is opened, and the installation of the top loading door 14a and the bottom heater is simplified. It has a simple structure.

  The entire wall surface of the residual heat drying tank 16 is composed of the heat insulating material 7, and the belt conveyor 12 in the tank and the temperature sensor 9 for temperature management inside the residual heat drying tank 16 are arranged at the bottom. .

  Further, a carry-out door 14b is provided on the terminal end side in the conveyance direction of the article 13 to be cleaned by the in-tank belt conveyor 12, and an out-tank belt conveyor 12a is disposed on the outside thereof.

  Then, the object to be cleaned 13 is transferred from the upper end opening of the residual heat drying tank 16 to the upstream end in the conveying direction of the in-tank belt conveyor 12 while being placed on the conveying jig 13a. While the jig 13a and the object to be cleaned 13 move at a predetermined speed in the direction of the carry-out door 14b, the object to be cleaned 13 and the conveying jig 13a are each preheated and dried by the residual heat that they have.

  Further, since the atmosphere inside the residual heat drying tank 16 is kept warm by the heat insulating material 7 constituting the wall surface of the residual heat drying tank 16, it is effective to suppress the temperature drop of the cleaning object 13 and the conveying jig 13a. In addition, the preheat drying of the article 13 to be cleaned and the conveying jig 13a can be performed.

  In the case of the steam drying apparatus M2 of this modification, the configuration of the residual heat drying tank 16 is simple, the manufacturing cost of the residual heat drying tank 16 can be reduced, and the heater 8 is not used. Reduction of operating power, that is, operating cost can be realized.

  In other words, the steam drying apparatus M2 of the present modification has an advantage that steam drying of the object to be cleaned 13 can be realized at a lower cost compared to the case of the steam drying apparatus M1 described above.

According to the steam drying apparatus M2 of this modification, it is possible to obtain a clean dry state free from spots on the surface of the object to be cleaned 13 at a lower cost and without causing a decrease in productivity due to an increase in tact time. The effect of being able to be obtained is obtained.
Hereinafter, examples of steam drying using the steam drying apparatus M1 and the steam drying apparatus M2 of the present embodiment will be described.

Example 1
Using the preheat drying tank 6 of the steam drying apparatus M1 illustrated in FIG. 1, the temperature of the atmosphere inside the preheat drying tank 6 is set to a plurality of different values of 30 ° C., 35 ° C., and 40 ° C., Table 1 shows the results of implementation of the cleaning object 13 when the stationary drying time of the cleaning object 13 in the residual heat drying tank 6 is set to a plurality of different values of 30 seconds, 60 seconds, and 120 seconds.

As the optical element that is the object to be cleaned 13, a lens for an optical instrument having a diameter of 3 mm or more was used, and the presence / absence of a stain on the surface after drying was visually observed.
The cleanliness in the preheat drying tank 6 was such that the number of air particles (0.3 μm) in one cubic meter was 50 or less.

  Further, the entire steam drying apparatus M1 has an explosion-proof specification, and has a configuration including local exhaust in order to prevent a gas composed of solvent vapor such as the IPA vapor atmosphere 4 from leaking and leaking.

  In this case, the criteria for determining the presence or absence of stains on the object to be cleaned 13 is not allowed (x mark) when the surface of the object to be cleaned 13 is visually confirmed under illumination with a 60 W light bulb, and is not confirmed. Judgment criteria for judging a case as a pass (circle) was adopted.

  As is apparent from Table 1, no stains were generated on the object 13 to be cleaned when the temperature inside the preheat drying tank 6 was 30 ° C. or higher and the drying time was 60 seconds or longer.

(Example 2)
Next, in the preheat drying tank 16 of the steam drying apparatus M2 having the configuration illustrated in FIG. 2, the temperature inside the preheat drying tank 16 is set to 20 ° C. to 25 ° C. which is room temperature, and the object to be cleaned in the preheat drying tank 16 is cleaned. Table 2 shows the results of implementation of the article 13 to be cleaned when the stationary drying time of the article 13 is set to 30 seconds, 60 seconds, and 120 seconds.

In this case, a lens for an optical instrument having a diameter of 3 mm or more was used as the optical element that is the article 13 to be cleaned, and the lens after drying was observed.
The inside of the residual heat drying tank 16 was increased in temperature due to the residual heat of the article to be cleaned 13 and the conveying jig 13a, and the temperature of about 30 ° C. could be maintained without requiring heating by a heater or the like.

  And also in the case of this preheating drying tank 16, it passed with the drying time of 120 second in the inside of the preheating drying tank 16, and it was able to dry without generating a spot on the surface of the to-be-cleaned object 13.

(Comparative example)
In order to confirm the effect of drying in the residual heat drying tank 6, the state immediately after being transported from the IPA vapor drying tank 2 to the residual heat drying tank 6 is shown in Tables 1 and 2 as the drying time = 0 seconds. .
As in this comparative example, when the drying time was 0 seconds, all failed (x mark).

  As described above, according to the steam drying apparatus M1 and the steam drying apparatus M2 according to the embodiment of the present invention, the surface of the object to be cleaned 13 is free from spots without causing a decrease in productivity due to an increase in tact time. The effect that a clean dry state can be obtained is acquired.

That is, according to the steam drying apparatus M1 and the steam drying apparatus M2 of the present embodiment, it is possible to obtain a clean optical element free from spots due to poor drying in the steam drying process of the object 13 to be cleaned such as an optical element.
As a result, by providing a clean optical element free from spots due to poor drying, it is possible to contribute to the reduction of product defects of the optical element.

Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the organic solvent is not limited to IPA (isopropyl alcohol), and other organic solvents may be used.

  Further, the object to be cleaned is not limited to an optical element, and can be widely applied to articles that require precise drying, such as a semiconductor wafer and a hard disk substrate.

(Appendix 1)
A steam drying tank;
One or more residual heat drying tanks after steam drying;
An optical element cleaning / drying apparatus using an organic solvent.

(Appendix 2)
The apparatus for cleaning and drying an optical element according to appendix 1, wherein the residual heat drying tank includes a heating device capable of adjusting a temperature.

(Appendix 3)
A steam drying process in which the optical element is steam dried in a steam drying tank;
A step of preheating and drying the optical element in a preheat drying bath installed one or more after the vapor drying step;
An optical element drying method comprising:

(Appendix 4)
The apparatus for cleaning and drying an optical element, wherein the preheat drying tank of Appendix 1 is sealed.

(Appendix 5)
An apparatus for cleaning and drying an optical element, wherein a heat insulating material is provided on a lower surface and a side surface of the residual heat drying tank of Appendix 1.

(Appendix 6)
A cleaning / drying apparatus for an optical element, wherein a heater is installed in a lower part, a side part, or both of the residual heat drying tank of Appendix 1.

DESCRIPTION OF SYMBOLS 1 IPA immersion tank 2 IPA vapor drying tank 3 Heater 4 IPA vapor atmosphere 5 Cooling pipe 6 Preheat drying tank 7 Insulation material 8 Heater 9 Temperature sensor 10 Clean unit 11 Handling robot 11a Traverse rail 11b Carriage 11c Lifting arm 12 In-tank belt conveyor 12a Outside belt conveyor 13 To-be-cleaned object 13a Transport jig 14a Carry-in door 14b Carry-out door 15 IPA
16 Preheat drying tank M1 Steam dryer M2 Steam dryer

Claims (7)

A first treatment tank in which an object to be cleaned is vapor-dried with an organic solvent vapor;
A second treatment tank in which preheat drying of the object to be cleaned that has undergone the steam drying is performed;
A steam drying apparatus comprising: The steam drying apparatus according to claim 1.
The said 2nd processing tank was equipped with the temperature control means which adjusts the temperature of the said 2nd processing tank, The steam drying apparatus characterized by the above-mentioned. The steam drying apparatus according to claim 2,
The steam drying apparatus, wherein the temperature control means is a heater disposed on a wall surface of the second processing tank. The steam drying apparatus according to claim 1.
The said 2nd processing tank is sealed, The steam drying apparatus characterized by the above-mentioned. The steam drying apparatus according to claim 1.
A steam drying apparatus, wherein a heat insulating material is disposed on a wall surface of the second treatment tank. A first step of performing vapor drying of an object to be cleaned using vapor of an organic solvent;
A second step of performing preheat drying of the object to be cleaned that has undergone the steam drying;
A steam drying method comprising: The steam drying method according to claim 6,
In the second step, an atmosphere of the object to be cleaned is heated.