JP2010175092A - Method and device of drying - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drying method capable of properly drying a solvent and the like remaining on a surface of a workpiece after steam drying. <P>SOLUTION: This method of drying the cleaned workpiece 100 by using IPA (isopropyl alcohol) 120 includes a replacement process for replacing moisture attached to the workpiece 100 by cleaning, with IPA 120, a steam drying process for moving the workpiece 100 after the replacement process into a steam drying tank 5 and placing the workpiece in the steam of IPA 120, and an air blowing drying process for moving the workpiece 100 to the outside of the steam drying tank 5 after the steam drying process, and applying dry warm air to the workpiece 100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drying method after cleaning parts, and a drying apparatus that executes the drying method.

  Conventionally, as a drying method after washing various workpieces with a detergent and rinsing with pure water, the pure water adhering to the workpiece is replaced with a solvent such as isopropyl alcohol (IPA) or alternative chlorofluorocarbon. Then, a drying method called so-called steam drying and a drying apparatus for performing the drying method are performed by moving to an environment filled with vapor of the substituted substance and evaporating the substitution substance on the workpiece surface. Are known.

  Based on the principle of vapor drying, it is difficult to sufficiently dry the material on the workpiece surface unless the heat capacity of the workpiece, which is the object to be cleaned, exceeds a certain level. For this reason, for example, in the case of a work having a small heat capacity such as an optical element having a small diameter, there is a problem that IPA or the like remains on the work surface due to a shortage of heat capacity, and this gradually volatilizes to cause a stain on the surface. . In relation to this problem, a drying apparatus (for example, refer to Patent Document 1) provided with a dehumidifier or a drying apparatus (for example, refer to Patent Document 2) that blows air above a steam tank in which a steam environment is formed. Proposed.

Japanese Utility Model Publication No. 6-9130 Japanese Patent No. 2879294

However, in the drying apparatus described in Patent Document 1, only the dehumidification of the atmosphere is performed, and the substance on the workpiece surface is not actively dried. Therefore, a sufficient effect for preventing the occurrence of stains or the like cannot be obtained.
Moreover, in the drying apparatus described in Patent Document 2, the original purpose of blowing is to prevent the diffusion of solvent vapor, and blown air is only momentarily applied to an object to be cleaned such as a workpiece when it is pulled up after vapor drying. Therefore, there is still a problem that sufficient effects cannot be obtained.

  The present invention has been made in view of the above circumstances, and provides a drying method capable of satisfactorily drying a solvent or the like remaining on the surface of a workpiece after steam drying and a drying apparatus capable of performing the drying method. With the goal.

  A first aspect of the present invention is a drying method for drying a cleaned work using a solvent, the replacement step of replacing the water adhering to the work by cleaning with the solvent, and the step after the replacement step A vapor drying step in which the workpiece is moved into a vapor drying tank and placed in the vapor of the solvent; and after the vapor drying step, the workpiece is moved out of the vapor drying vessel, and a dry temperature is applied to the workpiece. And a blow drying process for applying wind.

  In the present invention, the “dry hot air” refers to a wind whose humidity is lower and the temperature is adjusted higher than the atmosphere of the space where the drying is performed. The “workpiece” includes a single part and a product or semi-finished product in which a plurality of parts are combined.

  According to the drying method of the present invention, by applying dry hot air to the work after the steam drying process in the blow drying process, the solvent remaining on the work surface and the like is quickly vaporized to prevent the occurrence of stains. The

  In the blast drying step, the dry hot air may be applied so that the temperature of the work surface is 48 percent or more of the boiling point of the solvent. In this case, the remaining solvent can be vaporized more rapidly.

  The workpiece may be an optical element having an optical axis, and in the blow drying process, the dry hot air may be applied so as to be orthogonal to the optical axis. In this case, the solvent on the optical surface can be vaporized better.

  A second aspect of the present invention is a drying apparatus that dries a cleaned workpiece using a solvent, and heats the solvent to form a space containing the solvent vapor therein and adheres to the workpiece by cleaning. Ventilation having a steam drying tank for volatilizing the solvent replaced with the moisture, and a blower unit that is provided outside the steam drying tank and applies dry hot air to the work conveyed from the steam drying tank And a drying unit.

  According to the drying apparatus of the present invention, the dry hot air is applied to the work that has been subjected to the steam drying in the steam drying tank by the blower drying unit, whereby the solvent remaining on the work surface or the like is quickly vaporized.

  According to the drying method and the drying apparatus of the present invention, it is possible to satisfactorily dry the solvent and the like remaining on the surface of the workpiece after the steam drying.

It is a figure which shows the structure of the washing | cleaning drying apparatus of 1st Embodiment of this invention. It is a figure which shows the workpiece | work and holder used as the object of the washing | cleaning drying apparatus. It is a figure which shows the steam drying tank and ventilation blowing part of the washing | cleaning drying apparatus. It is the table | surface which showed the relationship between the temperature in the workpiece | work surface of dry warm air, and the dry state of IPA which adhered. It is a figure which shows the positional relationship of the ventilation nozzle and workpiece | work in a ventilation drying part. It is a table | surface which shows an example of the relationship between the setting temperature of dry warm air, the distance of a ventilation nozzle and a workpiece | work, an air volume, and the temperature of dry warm air in the workpiece | work surface. It is a figure which shows the steam-drying tank and ventilation drying part of the washing-drying apparatus of 1st Embodiment of this invention.

A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram illustrating a configuration of a cleaning / drying apparatus 1 including a drying apparatus that executes the drying method of the present embodiment.
The cleaning / drying apparatus 1 is for cleaning and drying an optical element (hereinafter referred to as “work”) having a small diameter (for example, a diameter of 10 mm or less), a cleaning tank 2 for cleaning the work using a detergent, and a cleaning A rinsing tank 3 for rinsing the work cleaned in the tank 2 with pure water, a replacement tank 4 in which IPA for replacing water adhered to the work after rinsing is stored, and a steam drying tank for performing IPA vapor drying 5 and a blower drying unit 6 for blowing air to the work after steam drying.

  As the washing tank 2, the rinsing tank 3, and the replacement tank 4, those having a known configuration may be used as appropriate. The replacement tank 4 may store other solvent or the like instead of IPA. The movement of the workpiece between the above mechanisms is performed by the first robot 7 that can move in the vertical direction and in the horizontal direction.

  FIG. 2 is a diagram illustrating a conveyance mode of the workpiece 100 that is an optical element. The workpiece 100 is cleaned and dried in a state in which the workpiece 100 is held by a cage-like holder 110 configured by a metal or the like assembled in a lattice shape. As shown in a plan view in FIG. 2, a plurality of holding spaces 111 for holding the workpiece 100 are formed in the holder 111, and the workpiece 100 is accommodated in each holding space 111.

  The workpiece 100 has an optical surface 101 and is installed in the holding space 111 so that a plane orthogonal to the optical axis is parallel to (including substantially parallel to) the diagonal line of the holding space 111. And all the workpiece | work 100 is hold | maintained at the holder 111 so that the optical surface 101 may face the same direction.

  FIG. 3 is a view showing the steam drying tank 5 and the blower drying unit 6. IPA 120 which is a solvent is stored inside the steam drying tank 5. The IPA 120 is heated by the heater 8, and the steam of the IPA 120 stays in the steam drying tank 5. The vapor of the IPA 120 is cooled by the cooling pipe 9 provided in the upper part of the vapor drying tank 5 and returns to the liquid. Therefore, the steam of the IPA 120 stays in the space up to the height of the cooling pipe 9, and the steam line L is formed at almost the same height as the cooling pipe 9.

The blower drying unit 6 includes a conveyor 10 for transporting the holder 110 that holds the workpiece 100, and a blower nozzle (blower unit) 11 that blows air onto the workpiece 100 placed on the conveyor 10. Has been.
The conveyor 10 conveys the held workpiece 100 and the holding tool 110 to a mechanism (not shown) that performs a process after drying. The blower nozzle 11 is movable in the horizontal direction, and blows dry hot air DW whose temperature and humidity are adjusted to be constant by an adjustment mechanism (not shown) from above the workpiece 100.
In the present invention, the “dry warm air” is defined as a wind whose humidity is lower and the temperature is higher than the atmosphere of the space where the work 100 is dried. It is preferable to set the humidity of the dry hot air DW to be 20 percentage points lower than the atmosphere. For example, if the humidity of the atmosphere is 50%, the humidity of the dry hot air DW is preferably set to 30% or less.

  FIG. 4 is a table showing the relationship between the temperature of the dry hot air on the surface of the workpiece 100 and the dry state of the attached IPA. As shown in FIG. 4, when the temperature of the dry hot air on the surface of the workpiece 100 was 40 degrees Celsius (40 ° C.) or higher, the IPA was satisfactorily dried without causing a stain on the surface of the workpiece. Since the boiling point of IPA is approximately 83 ° C., it is considered that drying is performed satisfactorily when dry hot air is applied at a temperature of at least 48% of the boiling point of the solvent used on the workpiece surface. Further, the temperature of the dry hot air is more preferably set so that the temperature on the surface of the workpiece is equal to or higher than the boiling point of the solvent used, but is appropriately set in consideration of the material of the workpiece to be cleaned. Good. For example, the temperature of the dry hot air on the surface of the workpiece 100 may be lower than the boiling point of the solvent used, for example, as long as it is higher than the temperature of the atmosphere.

The temperature of the dry hot air DW is equal to or substantially equal to the set value of the adjusting mechanism described above in the vicinity of the outlet of the blower nozzle 11, but the temperature on the workpiece surface is the distance D between the blower nozzle 11 and the workpiece 100 shown in FIG. It changes depending on the air volume from the blower nozzle 11 and is not necessarily the same as the set value of the adjusting mechanism.
FIG. 6 is a table showing an example of a change in the temperature of the dry hot air DW on the surface of the workpiece 100 when the set temperature of the dry hot air DW by the adjusting mechanism is set to 150 ° C. and the distance D and the air volume are changed. . As shown in FIG. 6, the temperature on the workpiece surface decreases as the distance D increases. Even if the distance D is the same, the temperature on the workpiece surface decreases as the air volume increases. Therefore, it is preferable that the target temperature of the dry hot air DW on the workpiece surface is set, and the set temperature, distance D, air volume, etc. of the adjusting mechanism are appropriately set so that the target temperature is achieved. When set to the following, it is easy to control the target temperature of the dry hot air DW.

  The movement between the steam drying tank 5 and the blower drying unit 6 is performed by a second robot 12 having a configuration similar to that of the first robot 7 as shown in FIG. That is, the steam drying tank 5, the blower drying unit 6, and the second robot 12 function together as a drying device. Moreover, the ventilation drying part 6 may be installed in the space where the explosion-proof process with respect to the vapor | steam of IPA was given with the steam drying tank 5, and may be installed out of the said space.

An operation at the time of use of the cleaning / drying apparatus 1 configured as described above will be described.
First, the user arranges the plurality of workpieces 100 on the holder 110 as described above. The workpiece 100 is put in the cleaning tank 2, the rinse tank 3, and the replacement tank 4 in order by the first robot 7 while being held by the holder 110. Then, cleaning and rinsing are performed by a known method, and the pure water adhering to the workpiece 100 and the holder 110 after rinsing is replaced with IPA as a solvent in the replacement tank 4 (substitution step).

  At this time, as shown in FIG. 2, many IPA droplets 121 are attached to the holder 110 and the workpiece 100. Among these, particularly when the droplets adhering to the workpiece 100 or the droplets 121A adhering across the workpiece 100 and the holder 110 are not dried quickly, the surface of the workpiece 100 is stained. Cause.

The workpiece 100 pulled out from the replacement tank 4 is transferred from the first robot 7 to the second robot 12 and enters a steam drying process.
The steam drying process will be described.
The workpiece 100 held by the holder 110 is moved to a position below the steam line L in the steam drying tank 5 by the second robot 12. Then, the IPA is vapor-dried, and the vapor is condensed on the workpiece 100 and the holder 110, coalesces with the droplets 121 and 121A and flows down, but the droplets 121 and 121A remain due to the surface tension. become. Thereafter, when the vapor line L is crossed, the droplet 121 and the droplet 121A are volatilized by the heat of the work 100 and the holder 110 (because of the saturated vapor state below the vapor line L, it is volatilized even at a high temperature. do not do).

  After a predetermined time has elapsed, the workpiece 100 is pulled up from the steam drying tank 5 by the second robot 12, but since the workpiece 100 has a small diameter, the heat capacity is small, so that heat sufficient to completely vaporize the droplet 121 can be supplied. In other words, the droplet 121 may remain without being completely vaporized. In order to remove such droplets 121, blow drying is performed.

  The second robot 12 conveys the workpiece 100 to the blower drying unit 6 and places it on the conveyor 10. Then, the blow nozzle 11 applies the dry hot air DW set at a predetermined temperature and humidity to the lower work 100 while moving horizontally above the work 100 as shown in FIG. 5 (blow drying process). .

At this time, since the workpiece 100 is held by the holder 110 so that the optical axis is horizontal (including substantially horizontal) as shown in FIGS. 2 and 5, the dry hot air DW applied from above is 100 is applied so as to be orthogonal to the optical axis 100, and goes out below the holder 110 along the optical surface 101. By applying the dry hot air DW, the remaining IPA droplets 121 are vaporized by receiving heat supplied from the dry hot air DW. In addition, the dry warm air DW also increases the saturation allowable amount of the IPA vapor in the atmosphere around the workpiece 100, and the IPA is more easily vaporized. By these actions, the IPA droplet 121 is suitably dried and completely disappeared, and the occurrence of stains is prevented.
After the blow drying, the conveyor 10 conveys the workpiece 100 and the holder 110 to an apparatus that performs the next process.

  According to the above-described drying method using the cleaning / drying apparatus 1 of the present embodiment, the work 100 that has been steam-dried in the steam-drying tank 5 is quickly moved to the air blowing / drying unit 6 and is supplied from the air-blowing nozzle 11 to a predetermined amount. Dry hot air DW adjusted to temperature and humidity is applied. Therefore, even when the IPA droplet 121 that has not been vaporized in the vapor drying remains, it is quickly vaporized by the dry hot air DW, and thus suitable drying is performed without causing a stain on the surface of the workpiece 100. be able to.

  Further, since the dry hot air DW is applied so as to be orthogonal to the optical axis of the workpiece 100, the dry hot air flows along the optical surface 101 and escapes below the holder 110. For this reason, the dry hot air DW is applied uniformly to the optical surface 101. Accordingly, it is possible to more suitably prevent the occurrence of a stain on the optical surface 101 that greatly affects the quality of the optical element as a workpiece.

  Furthermore, since the dry hot air DW is applied to the workpiece 100 held by the holder 110 in a state of being aligned in the horizontal direction in the vertical direction perpendicular to (including substantially perpendicular to) the alignment direction, the droplet 121 is temporarily assumed. Is blown off by the dry hot air DW, the work 100 does not exist in the direction in which the droplets 121 are blown off. Therefore, the solvent droplets that have been blown off do not adhere to other workpieces, and in the blow drying process, the occurrence of stains due to the droplets adhering to one workpiece adhering to other adjacent workpieces is prevented. can do.

  In addition, since the dry hot air DW is applied after the work 100 after the steam drying is moved out of the steam drying bath 5, the dry hot air DW does not affect the inside of the steam drying bath 5. Therefore, the steam line L is not disturbed by the turbulence of the air flow in the steam drying tank 5, and the work 100 can be satisfactorily performed without increasing the risk of explosion due to the steam of the IPA 120 escaping above the steam line L. Drying can be performed.

  In the present embodiment, the example in which dry hot air is applied to the work on the conveyor 10 while the blower nozzle 11 moves is described. Instead, the blower nozzle 11 is fixed and the conveyor 10 is operated. Therefore, the blower nozzle 11 may be configured to move relative to the workpiece 100. If it does in this way, since the workpiece | work 100 will be blown and dried while being conveyed, the time until it transfers to a next process from a ventilation drying process can be shortened, and work efficiency can be improved.

  Next, a second embodiment of the present invention will be described with reference to FIG. The difference between the drying method of the present embodiment and the drying method of the first embodiment described above is how to apply dry hot air. In addition, the same code | symbol is attached | subjected to the structure which is common in the above-mentioned 1st Embodiment, and common description is abbreviate | omitted.

  FIG. 7 is a view showing the steam drying tank 5 and the blower drying unit 22 of the cleaning / drying apparatus 21 of the present embodiment. The blower drying unit 22 is provided with a blowout port (blower unit) 23 having an opening area that covers the entire upper surface of the holder 110 instead of the blower nozzle 11.

  A procedure for drying using the steam drying device 21 will be described. The workpiece 100 and the holder 110 that have been steam-dried by the same method as in the first embodiment are pulled up from the steam-drying tank 5 by a second robot 12 (not shown) and placed on the conveyor 10 of the blower-drying unit 6. The

  The workpiece 100 and the holder 110 are moved to the lower side of the outlet 23 by the conveyor 10. Then, the dry hot air DW is applied to all the workpieces 100 from the outlet 23 at a time. After the remaining IPA droplets disappear, the workpiece 100 and the holder 110 are conveyed by the conveyor 10 to a mechanism that performs the next process.

Also in the drying method of this embodiment, the same effect as the drying method of the first embodiment described above can be obtained.
Moreover, since the dry hot air DW is applied to all the workpieces 100 at a time, it is not necessary to provide a moving mechanism or the like at the outlet 23, the configuration of the apparatus can be simplified, and it is required for the blow drying process. Time can be shortened and work efficiency can be improved. Further, since the dry hot air DW is applied over a wide range at once, the saturation allowable amount of IPA vapor in the atmosphere around the workpiece 100 is further increased, and the time difference in which the dry hot air DW hits a plurality of workpieces 100 is increased. In addition, since there is no temperature difference, the remaining droplets can be dried more satisfactorily.

  In the present embodiment, the example has been described in which the single outlet 23 applies the dry warm air DW to the workpiece 100 without moving, but each of them has an opening area of about the holding space 111. A plurality of air outlets may be arranged and arranged, and dry hot air may be applied to the work 100 held in each holding space 111 from each air outlet. If it does in this way, dry warm air can be efficiently applied by each workpiece | work, and ventilation drying can be performed more favorably. In addition, it becomes easier to control the flow rate of the dry hot air and the target temperature.

  Although the embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above-described embodiments, an example has been described in which the workpieces are arranged in the holder in the horizontal direction and the dry hot air is applied vertically (including substantially vertical) from above to below the workpiece. However, instead of this, the workpieces may be arranged in a vertical direction on the holder, and the dry hot air may be applied horizontally (including substantially horizontal). Even in this case, since there is no work downstream of the dry hot air from which the remaining solvent droplets of IPA or the like are blown off, similarly, the stains caused by the blown-off droplets adhering to other workpieces. Occurrence can be prevented.

1, 21 Washing and drying device 5 Steam drying tank 6, 22 Blowing and drying unit 11 Blowing nozzle (blowing unit)
23 Outlet (Blower)
100 Workpiece 101 Optical surface 120 Isopropyl alcohol (solvent)

Claims (4)

A drying method for drying a cleaned work using a solvent,
A replacement step of replacing the water adhering to the workpiece by washing with the solvent;
A vapor drying step of moving the workpiece after the substitution step into a vapor drying tank and leaving it in the vapor of the solvent;
After the steam drying step, the work is moved out of the steam drying tank, and a blow drying step of applying dry warm air to the work,
A drying method comprising:   2. The drying method according to claim 1, wherein in the blow drying process, the dry hot air is applied to the surface of the workpiece so as to have a temperature of 48 percent or more of a boiling point of the solvent. The workpiece is an optical element having an optical axis,
3. The drying method according to claim 1, wherein, in the blow drying process, the dry hot air is applied so as to be orthogonal to the optical axis. A drying device for drying a cleaned workpiece using a solvent,
A vapor drying tank for heating the solvent to form a space containing the vapor of the solvent in the interior, and volatilizing the solvent replaced with the water adhering to the workpiece by washing;
A blower drying unit that is provided outside the steam drying tank and has a blower unit that applies dry hot air to the work conveyed from the steam drying tank;
A drying apparatus comprising:

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