JPS6348598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology belongs to the field of cleaning of optical lenses, semiconductor wafers, etc. in a completely dust-free state down to the submicron level, and subsequent drying technology.

<Summary of the gist> The present invention provides a method for cleaning dried objects (workpieces) such as optical lenses and semiconductor wafers during their manufacturing process.
The cleaning and drying tank in which the final cleaning and drying is performed after the primary cleaning after the stocking step has a heater for evaporating alcohol on the lower side of the lower surface of the cleaning and drying tank. has an alcohol chamber storing alcohol from the bottom, and an alcohol vapor cleaning semi-drying chamber stacked on top of the alcohol chamber, and the alcohol chamber is connected to a condensation drain device provided in the alcohol vapor cleaning semi-drying chamber, It is connected to a separate alcohol separation and recovery device, and an inert gas drying chamber is provided above the alcohol vapor cleaning semi-drying chamber into which an inert gas such as argon gas, which has a lower specific gravity than the alcohol, is diffused and injected. connected to a gas source, the inert gas drying chamber having its upper portion exposed to the atmosphere to block direct flow of the atmosphere into the alcohol vapor cleaning semi-drying chamber;
Further, the invention relates to a washing/drying apparatus in which the inert gas drying chamber is of an overflow type at the upper end of the washing/drying tank, and in particular, the alcohol vapor washing semi-drying chamber is provided with the alcohol vapor through a filter in the middle. The alcohol vapor generation chamber is divided into two parts and connected to an alcohol vapor generation chamber at the front stage and a cleaning and drying chamber at the rear stage, and the drain of the cleaning and drying chamber and the alcohol chamber are circulated through a circulation pipe to form the alcohol steam generation chamber. This invention relates to a dust-free washing and drying device in which submicron-sized dirt is collected and filtered on the side.

<Prior Art> As is well known, in the optical industry and the electronic industry, extremely high precision is required for ultra-precision parts.

The manufacturing technology has been developed to a considerable extent, but as precision becomes required down to the micron level, it is not just the manufacturing technology, but also the manufacturing process for each product. The accuracy of the cleaning process that follows this process becomes extremely important.

In other words, the submicron-sized contamination that inevitably adheres during the manufacturing process of these ultra-precision parts takes on the appearance of a complex contamination, which can simply be thoroughly cleaned with organic solvents, builder agents, surfactants, etc. In addition, there is a possibility that this may occur because the cleaning liquid used for this purpose does not have a sufficiently high purity. Therefore, the vapor rinse after the subsequent rinse water process, is the surrounding air during the drying process,
Alternatively, if the cleaning agent contains submicron dirt, there is a drawback that completely dust-free workpieces cannot be cleaned and dried. Even though the manufacturing technology itself was quite advanced, the precision of washing and drying the products could not keep up, making it difficult to obtain the precision of the products.

Therefore, in order to completely obtain such dust-free cleaning and drying, considerably complicated equipment is required to manage and control it, which has the disadvantage of increasing costs. There was also a problem that the results were not completely as expected.

Conventionally, the cleaning/drying apparatus used for the final cleaning and drying of ultra-precision parts of this type has, for example, a heater 2 provided below the cleaning/drying tank 2 of the cleaning/drying apparatus 1, as shown in FIG. The alcohol 4 stored in the lower part of the cleaning/drying tank is heated to form a cleaning semi-drying chamber 5, and the alcohol vapor is condensed by cooling the condenser 6 installed at the upper part. A boundary surface 8 is formed with the atmosphere 7, and the condensed alcohol and moisture in the atmosphere are transferred to the alcohol 4 in the alcohol chamber 3 from the circulation pipe 10 via the drain 9.
Alcohol separation and recovery equipment 1
3, the water 14 is separated and passed through a filter 15 and pump 16 to be recovered and used again in the alcohol chamber 3. Also, the workpiece 17 that has been finished washed with rinsing water in the first washing step is transferred to an elevator system. Liquid alcohol is lowered into the cleaning and drying tank 2 and mixes well with water due to its affinity, but alcohol vapor is repelled by water. It is displaced by the alcohol vapor inside and falls,
The fallen water passes through the tray 18 and condenses on the work in the separation and recovery cooler 12, where it joins together with the fallen alcohol, where the alcohol is recovered and the water is removed in the separation and recovery 13.

The workpiece 17 was then washed with alcohol and semi-dried in several tens of seconds, dried in the upper air chamber, and then transported to the next stage.

Furthermore, compared to the above-mentioned embodiment, the embodiment shown in FIG. 2 is an embodiment in which the washing and drying tank is divided into two parts parallel to each other and connected in communication, but substantially the same effect is achieved.

Meanwhile, 1, of the seed finishing washing drying equipment.
In 1', the alcohol that circulates and is stored in the alcohol chamber 3 is, in principle, highly pure alcohol, but strictly speaking it is not 100% pure alcohol, and even has some submicron level alcohol. It often contains particulate dirt, so when it is heated and boiled in the alcohol chamber 3 by the heater 2, the alcohol vapor is generated and the submicron level dirt in the alcohol also rises up, making it difficult to clean. The workpiece 17 becomes suspended in the drying chamber 5 and is lowered into the cleaning semi-drying chamber 5. The rinsing water and alcohol vapor adhering to the workpiece 17 in the previous process are replaced as described above. When alcohol vapor rinsing is performed subsequently, there is a drawback that the subminion unit stains inevitably adhere to the surface of the workpiece.

This, combined with the submicron level dirt brought in by the cleaning process in the previous process, results in an ironic phenomenon in which it is impossible to tell whether the cleaning is being done or whether the submicron level dirt is increasing again. It was hot.

Also, the alcohol vapor in the steam cleaning semi-drying chamber 5 rises, and an interface 8 with the atmosphere 7 at its upper end is formed by the condenser 6, and the alcohol vapor in the lower alcohol chamber 3 is directly absorbed by the drain 9. 4, the water concentration in the alcohol 4 in the alcohol chamber 3 increases, and this tendency is particularly strong during the rainy season, as well as in the winter.
There was also a problem that there was a lot of water vapor in the cleaning semi-drying chamber 5, and therefore drying did not proceed smoothly.

In addition, in such a case, as shown in the figure, the cooler 1
2, and when a large amount of condensed water is separated by circulation to the separation and recovery device 13, the separation and recovery device 1
3 has become larger and the power used has also increased,
The disadvantage was that not only the initial cost but also the running cost was high.

Furthermore, since the cleaning/drying tank is generally made of stainless steel, the integral type allows heating conduction by the lower heater 2 to be conducted to the upper condenser 6.
This competes with the cooling of
There was also the disadvantage that power costs increased on both sides.

Furthermore, as shown in the figure, the cleaning semi-drying chamber 5 is exposed to the atmosphere 7.
Because the alcohol vapor is connected to the atmosphere and is in contact with the atmosphere, it is easy for moisture from the atmosphere to get mixed in, which has the disadvantage of suppressing drying as mentioned above. There is a risk that the alcohol may get mixed in with the alcohol vapor and adhere to the workpiece 17 during replacement with the above-mentioned rinsing water, and since the oxygen is in direct contact with the alcohol vapor, there is a large risk of ignition.

After cleaning and semi-drying, the workpiece 17 is lifted into the atmosphere, but in this case, there may be a slight amount of condensed alcohol attached to the workpiece 17, which will dry in the upper atmosphere 7. However, since the evaporation time is included in the drying time, the drying time becomes longer, resulting in poor operating efficiency.

In addition, this slight amount of adhering alcohol may evaporate in the air after being pulled up, and during this time there is a risk that submicron-level contamination in the air may adhere. There was also the problem that once dirt adhered and dried, it could not be easily removed.

<Objective of the Invention> The object of the present invention is to solve the technical problem of the inability to remove submicron stains during washing and drying using alcohol vapor following the preceding process based on the above-mentioned prior art, and While taking advantage of the advantage of replacing the liquid of the workpiece with rinsing water with alcohol vapor, it is possible to absolutely prevent submicron level contamination from adhering to the workpiece, and to ensure that it dries. It is an object of the present invention to provide an excellent dust-free cleaning and drying device that can perform final cleaning and drying safely without the risk of ignition and is useful for cleaning applications in the precision parts manufacturing industry.

<Means/effects for solving the problems> In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims in accordance with the above-mentioned object, is to solve the above-mentioned problems. It is divided into two parts, an upper and a lower washing and drying tank, to separate the heating and cooling heat systems to improve operational efficiency, and the heat is stored at the bottom of the lower washing and drying tank. The alcohol is heated and pressurized in the alcohol vapor generation chamber at the bottom of the cleaning semi-drying chamber, and in the process it passes through the filter in a vapor phase without being liquefied, it captures submicron dirt and condenses on the top. The condensed alcohol vapor is condensed in the container and circulated through the drain to the lower side of the alcohol, where it is heated and evaporated to ensure submicron dirt is captured, and the filtered alcohol vapor is completely dust-free and sent to the washing and drying room. In the upper part of the cleaning drying chamber, a high-purity inert gas having a specific gravity lower than that of alcohol is filled from the supply source at a set pressure into the inert gas drying chamber, and the alcohol vapor is At the same time, there is always a slight overflow at the upper end of the washing/drying tank to ensure that a large amount of air does not enter into the washing/drying tank from above, and to prevent submicron units of air from entering the washing/drying tank. This prevents dirt from entering the engine, and by preventing air from entering the engine, it also prevents ignition and allows operation in a safe condition.These conditions are constantly monitored by sensors and automatically controlled. And then,
The workpieces are lowered in an elevator from the top of the cleaning/drying tank, and quickly pass through the inert gas drying chamber, where the attached rinsing water is replaced by completely dust-free alcohol vapor, and the workpieces fall. After that, the workpiece is rinsed with alcohol vapor and gently pulled up in a semi-dry state.The small amount of alcohol adhering to the workpiece is quickly dried in the high-purity inert gas drying chamber mentioned above. Since it is also isolated from the atmospheric phase, the adhesion of submicron level dirt from the atmosphere is prevented.
Washing and drying is completed in an almost completely dust-free state and transferred to the next stage, and the rinsing water that falls in the washing and drying room is drained from the cooler through a separation and recovery device and condensed on the workpiece. The fallen alcohol passes through a filter and is collected and stored in the alcohol chamber as high-purity alcohol, so that the cleaning and drying can be carried out safely, efficiently, and completely dust-free. This is what I learned.

<Embodiment - Configuration> Next, one embodiment of the present invention will be described below based on FIG. 3. Note that the same parts as in FIGS. 1 and 2 will be described using the same reference numerals.

1'' is a washing/drying device which constitutes the gist of this invention, and its washing/drying tank has a pair of upper and lower washing/drying tanks 1.
As shown in the figure, the opposing flange surfaces of the two halves 8 and 18' are bolted together via a heat insulating material 19 such as asbestos, and are thermally isolated from each other, but are sealed from the outside. However, the two are vertically connected.

The upper and lower washing and drying tanks 18, 18' are basically cylindrical in cross section and are made of stainless steel, with a stepped shoulder extending inward from the flange of the lower washing and drying tank 18'. A portion 20 is formed,
An electrostatic adsorption filter 22 is hung vertically in a cylindrical shape over the shoulder of the saucer part 21 at the center of the lower end, and is further pressed by a filter holder 23 made of a stainless steel punched perforated plate inside, so that it can be replaced with the shoulder part 20. is fastened with bolts.

Therefore, the filter 22 and the holder 23 have a lower washing/drying tank 18' formed inside and outside, and an alcohol chamber 3 for storing alcohol 4 is located below the outer donut-shaped part. is formed,
A heater 2 for heating is provided below it.

Further, an alcohol vapor generation chamber 5', which is a semi-drying chamber for cleaning using alcohol vapor in the alcohol chamber 3, is formed, and a cleaning and drying chamber 5'' is formed inside thereof.

Then, in the previous process, the electrical resistivity was reduced to 5×10 ³ Ω−
Workpieces 17, such as semiconductor wafers, which have been washed with rinsing water of less than cm and are transported in a basket, are transported to the elevator through an opening (not shown) of a filter 25 provided in the upper opening 24 of the upper cleaning/drying tank 18, as shown in the figure. It is quickly lowered into the washing and drying chamber 5'' as shown in the figure, and
The rinsing water adhering to the cleaning and drying chamber 5'' is replaced by the alcohol vapor, as described above, so that cleaning and semi-drying is carried out.

Further, the condenser 6, which is located near the lower flange of the upper washing/drying tank 18, applies a predetermined cooling-down effect to the alcohol vapor through cooling water piping, and brings the height of the vapor phase surface to a set height. A circulation pipe 10 is connected to the alcohol chamber 3 from a drain 9 provided on the flange, and the condensed alcohol is circulated and supplied to the alcohol 4 in the alcohol chamber 3 by the condenser 6. Therefore, through the filters 22 and 23, a circulation path is formed as shown by the arrow through the alcohol vapor generation chamber 5', the washing and drying chamber 5'', the drain 9, and the circulation pipe 10. By being formed in a loop, the filter 2 of the alcohol vapor generation chamber
As mentioned above, 2 and 23 are unavoidably alcohol 4
Therefore, by performing a preliminary operation for a set time before washing and drying, the filter 22 completely captures the submicron dirt mixed in the alcohol. Therefore, the interior of the alcohol vapor in the cleaning/drying chamber 5'' is completely dust-free.

A lower pipe 28 extends from the small diameter opening 27 of the lower tray 21 of the lower cleaning/drying tank 18' and is connected to the alcohol chamber 3, and connects the cooler 12, An alcohol separation and recovery device 13, a filter 15 of, for example, 0.1 micron, and a pump 16 are provided.

Water that falls from the workpiece 17 in the washing and drying chamber 5'' is drained 14 by the alcohol separation and recovery device 13, and only the alcohol that has condensed and fallen on the workpiece is made highly purified and recovered in the alcohol chamber 3 again. are being supplied.

When the washing and drying is completed, the alcohol 4 in the alcohol chamber 3 is immediately cooled down by the cooler 12 via the pipe 29, and recovered into the high-purity alcohol tank 30 using the head difference. or, if there is no head, another bypass pipe 3 via the pump 31.
2, the alcohol is immediately collected in the high-purity alcohol tank 30, and when restarting washing and drying, the pump 31 passes through a 0.1 micron filter 33, similar to the filter 22 in the washing semi-drying chamber 5, to the pipe 34. The high-purity alcohol 4 is supplied to the alcohol chamber 3 by this.

Regarding the control of the circulation and distribution of the alcohol 4 and the distribution from the alcohol tank 30, level sensors 35 installed at the upper and lower levels of the alcohol chamber 3 send electricity to an appropriate control device 36 built in a microcomputer. The electromagnetic valves and pumps 16 and 31 are connected to each other to start and stop the solenoid valves and the pumps 16 and 31 to maintain the level of alcohol 4 in the alcohol chamber 3 within a set range.

Further, the heater 2 is provided with a sensor 37 for controlling the temperature of the heating surface and an overheat sensor 38, so that when the heating temperature falls outside the set range, an alarm lamp 39 and an alarm buzzer 40 are activated. , the power is cut off in the event of overheating.

In addition, a temperature sensor 41 is installed in the condenser 6 provided in the upper part of the washing and drying chamber 5'', that is, in the lower part of the upper washing and drying tank 18. That is, in a state where the heater 2 is overheated and the enthalpy of alcohol vapor becomes large, the alarm lamp 3
9, and the control device 36 so as to operate the alarm buzzer 40 and cut off the power to the heater 2.
input the detection signal to the

On the other hand, in the upper part of the washing and drying chamber 5'' in the middle of the washing and drying tank, a cylinder 42 of an argon gas source as an inert gas is installed to supply an inert gas drying chamber 43 to the washing and drying chamber 5''. A vapor phase surface of the alcohol vapor filling the cleaning/drying chamber 5'' is introduced into the inert gas drying chamber 43 through a well-known diffusion/inflow device 44 formed from the upper part up to the opening 24 and provided inside the opening 24. The electromagnetic valve is adjusted by the control device 36 so that the washing and drying tank 18 is supplied so as not to be disturbed, and the electromagnetic valve is controlled by the control device 36 so that the washing and drying tank 18 is overflowed little by little from the opening 24.

In this case, an argon gas sensor 45 is provided at a set distance below the opening 24 of the cleaning/drying tank 18.
The argon gas level detection signal of
6, the solenoid valve 46 is opened and closed depending on the level, thereby ensuring that the argon gas always overflows from the upper opening 24 and preventing atmospheric air from entering through the opening 24. This prevents moisture and submicron dirt from entering the tank, and also prevents ignition caused by outside air entering the tank.

In addition, in order to prevent outside air from unexpectedly entering through the opening 24 and contacting oxygen with the vapor phase surface 8 of alcohol vapor in the cleaning/drying chamber 5'', the argon gas sensor 45 is located further below the argon gas sensor 45 by a set distance. An oxygen sensor 47 is provided at the argon gas supply cylinder 42, and its detection signal is inputted to the control device 36, and the electromagnetic valve 4 is configured to increase the amount of argon gas supplied from the supply cylinder 42.
6 is opened and closed, and an alarm lamp 39 and an alarm buzzer 40 are operated.

Further, the temperature sensor 41 of the condenser 6 provided on the outer wall of the inert gas drying chamber 43 also
When the temperature is detected and exceeds a set temperature, an alarm lamp 39 and an alarm buzzer 40 are activated.

In addition, a pipe 48 is taken out from another drain 9 provided in the inert gas drying chamber 43 and connected to the alcohol separation and recovery device 13, so that it can be used unexpectedly or during drying in the process of lifting the workpiece 17. The attached alcohol is then evaporated in argon gas and condensed in a condenser 6, and is then recovered and supplied to the alcohol chamber 3 again.

Further, 49 is a fire extinguishing nozzle, which is connected to an automatic fire extinguishing device (not shown).

Therefore, as shown on the left side of the figure, in the dust-free cleaning and drying apparatus 1'', the inert gas drying chamber 43 is the drying process (a), and the gas phase interface between the argon gas and alcohol vapor is From 8 to alcohol lower 3
The cleaning and drying steps 5' and 5'' up to (b) are vapor rinsing cleaning and semi-drying steps.

<Embodiment - Effect> In the above configuration, all the sensors 35, 37, 38, 41, 47, 45, etc. are activated by the control device 36, and the control device 36 causes the high purity alcohol tank 30 to flow through the pump 31. A 0.1 micron filter 33 is passed through the opened and closed electromagnetic valve.
After that, high-purity alcohol 4 is supplied into the alcohol chamber 3 through the pipe 34, and stored in a set amount via the level sensor 35.

On the other hand, when the heater 2 is activated to heat the alcohol 4, the alcohol evaporates and becomes alcohol vapor, which fills the alcohol vapor generation chamber 5' and increases the pressure. The electrostatic adsorption filter 22 remains as it is, and
It fills the cleaning/drying chamber 5'' through the perforated stainless steel mesh 23, condenses due to the cooling operation of the condenser 6, and begins to circulate through the pipe 10 to the alcohol 4 in the alcohol chamber 3.

Therefore, by repeating this process for a predetermined period of time, the filter 22 completely captures submicron-sized dirt from the alcohol vapor in the cleaning/drying chamber 5'', turning it into filtered, dust-free alcohol vapor, and removing the vapor phase. Surface 8 reaches a predetermined level.

On the other hand, argon gas containing almost no submicron particles from the high-purity argon gas cylinder 42 fills the inert gas drying chamber 43 from above the gas phase surface 8 through the diffusion/inflow device 44, By continuously supplying the water, a set amount of water overflows from the opening 24 of the upper washing/drying tank 18 little by little.

In this case, the problem with alcohol as a liquid is that ethanol, which has good hydration properties, has a molecular weight of 46 and is somewhat light, while isopropyl alcohol (IPA), which has slightly poor hydration properties, has a molecular weight of 60 and is difficult to use when using argon gas. Because it is sufficiently larger than that of 39, the upper part of the gas phase interface 8 is filled with floating argon gas,
Moreover, nitrogen gas, oxygen, which makes up most of the air,
Also, since the molecular weights of water vapor are 28, 32, and 18, which are smaller than the molecular weight of argon gas, 39, the atmosphere is less likely to enter and settle in the argon gas overflowing from the opening 24.

Moreover, in this state, the opening 2
If the atmosphere enters from 4, oxygen sensor 47
detects this and supplies the solenoid valve 46 of the cylinder 42 of the argon gas supply source via the control device 36 to increase the supply amount and bring the oxygen into contact with the alcohol vapor cleaning semi-drying chamber 5''. To eliminate the possibility of ignition, etc., and to prevent moisture contained in the atmosphere from entering the cleaning/drying chamber 5'' during the rainy season.

Further, when the upper limit of the argon gas in the inert gas drying chamber 43 decreases, the argon gas sensor 45 detects this and adjusts the opening/closing of the electromagnetic valve 46 of the cylinder 42 to remove the argon gas from the opening 24. Always guarantee overflow from .

Of course, the moisture in the atmosphere that accidentally enters in the above-mentioned process is condensed by the upper condenser 6, which is always in operation, and separated from the drain 9 by the alcohol separation and recovery device 13 via the pipe 48, and then drained to the drain 14.

In this way, when each alcohol vapor and argon gas are automatically adjusted and filled, the workpiece 17 completes the final cleaning process (not shown) in the previous step and has an electrical specific resistance of 5×10 ³ Ω. ―
cm or less of rinsing water, the filter 25 is wetted by an elevator (not shown), and is quickly lowered from the filter 25 to the upper opening 24 of the washing/drying tank 18 as shown by the arrow. Stop at a position.

During this time, the workpiece 17 is passed through the argon gas in the inert gas drying chamber 43 and lowered.
A portion of the rinsing water that wets the alcohol is subjected to a drying action, but the separated water is drained 14 from the drain 9 via the pipe 48 to the alcohol separation and recovery device 13 as described above.

As mentioned above, the adhering rinsing water of the work 17 stopped in the cleaning/drying chamber 5'' is immediately replaced by the alcohol vapor, and the submicron particulate dirt floating in the rinsing water film is transferred to the receiving tray 21. It falls, alcohol vapor condenses on its surface, rinses it, and soon it becomes semi-dry.

In this way, cleaning and quasi-drying can be carried out within a few tens of seconds in a completely dust-free state.

The rinsing water and alcohol that have fallen into the saucer 21 are then transferred to the cooler 12 via the pipe 28.
The alcohol is separated by the alcohol separation and recovery device 13, the water is drained 14, the alcohol passes through the filter 15 and is recovered by the pump 16 into the alcohol 4 in the alcohol chamber 3, and is circulated through the above-mentioned circulation path. Guaranteed filter 22
This filter captures and filters submicron-sized dirt.

As mentioned above, the cleaned workpiece 17 is pulled up from the opening 24 as shown by the arrow after several tens of seconds and moved on to the next step. When it rises and enters the argon gas in the gas drying chamber 43, it is immediately dried and the attached alcohol evaporates.
It is condensed by the condenser 6, separated by the alcohol separation and recovery device 13 via the pipe 48, and then passed through the filter 15 again to the alcohol chamber 3 as described above.
It is recovered to alcohol 4 inside.

Then, it is completely dust-free dried and exits from the opening 24 to be transferred to the next step.

During this time, as mentioned above, the atmosphere does not enter due to argon gas, and therefore the submicron level contamination in the atmosphere does not enter, and the reason why the atmosphere does not enter is because the oxygen is blocked by the argon gas (as mentioned above). Since oxygen has a lower specific gravity than argon gas (as shown in FIG.

Of course, in case of emergency, use the above fire extinguishing nozzle 4.
9 is activated.

Additionally, if oxygen accidentally enters the gas phase surface 8 of alcohol vapor, this is detected by the oxygen sensor 47 and the control device 36 operates the alarm lamp 39 and alarm bell 40, and also reduces the amount of argon gas supplied. will be made to increase.

During this time, alcohol 4 in alcohol chamber 3
The amount of alcohol is detected by the level sensor 35, and is returned to the alcohol tank 30 through the supply pump 31 or the discharge pipe 29 to maintain a predetermined set level, and a predetermined primary cleaning is performed at the previous stage in sequence. Each completed workpiece 17 is finished washed and dried, and is completely dust-free dried and transported to the next step.

When the washing and drying is completed, the discharge pipe 29 or the pump 31 is operated as described above to recover the alcohol 4 in the alcohol chamber 3 into the alcohol tank 30.

It goes without saying that the embodiments of the present invention are not limited to the above-mentioned embodiments. For example, the target workpieces are not limited to semiconductor wafers and optical lenses, but can also be applied to various other ultra-precision cleaning products that require cleaning. Of course it is possible.

As the cleaning alcohol, ethanol, isopropyl alcohol, or an azeotropic solution of ethanol and chlorofluorocarbons can also be used.

<Effects of the Invention> As described above, according to the present invention, basically, the ultra-precision manufactured parts such as semiconductor wafers are primarily cleaned of oil stains and other contaminants that have adhered during the manufacturing process and storage process in the previous process. Finally, the electrical resistivity becomes 5×
In the process of washing with rinsing water of 10 ³ Ω-cm or less and moving on to the next vapor rinsing and drying process, the work may be mixed with the rinsing water that adheres wetly to the workpiece that is unavoidably brought in, or it may be contaminated with water in the air. Submicron level dirt in the air that is transported
In addition, submicron level dirt that is inevitably mixed in ethanol, isopropyl alcohol, etc. is completely removed, resulting in an excellent effect of washing and drying in a completely dust-free state.

In addition, since the final cleaning and drying process is completely dust-free, the precision of the final product improves, and as manufacturing technology improves, the precision of the product improves dramatically. The excellent effect of being able to do this is achieved.

In addition, in the washing/drying tank, an alcohol chamber is formed on the lower side, a washing semi-drying chamber is formed above the washing drying chamber, and an inert gas drying chamber is provided on the upper part to reduce the interaction between the atmosphere and alcohol vapor. An inert gas such as argon gas is interposed in between, so even if the rinsing water is wet and adheres to the surface of the work being carried in, it is quickly replaced by alcohol vapor and the work is cleaned and semi-dry. In the process of being lifted up and passing through an inert gas drying chamber, the alcohol remaining on the workpiece is completely evaporated and dried in an extremely short period of time.

Since an inert gas drying chamber is provided between the cleaning and drying chamber and the atmosphere, the argon gas and other gases block the atmosphere and alcohol vapor, preventing oxygen from the atmosphere from entering. As a result, there is an effect that washing and drying can be carried out safely without the occurrence of fires, and further, more complete dust-free washing and drying is promoted because submicron level dirt in the atmosphere does not enter.

In this invention, since the cleaning and drying tank has an alcohol vapor generation chamber and a cleaning and drying chamber that are separated by a filter, the alcohol in the alcohol chamber is heated and evaporated by the heater and is not liquefied but is converted into a gas phase. Completely dust-free in the cleaning process is effectively promoted because it is automatically self-dust-free in the process of passing through the filter and circulating through the circulation path from the drain by the upper condenser. This is an excellent effect.

In this way, even though it is assumed that there is submicron-scale dirt from the atmosphere during transportation or hidden in the alcohol used for washing and drying in the previous process, the washing is completely dust-free. This provides an excellent drying effect.

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views of a washing and drying apparatus based on the prior art, and FIG. 3 is a schematic cross-sectional view of an embodiment of the present invention. 1''...Dust-free washing and drying device, 18, 18'...Washing and drying tank, 2...Heater, 3...Alcohol chamber,
5... Washing semi-drying room, 13... Alcohol separation and recovery device, 6... Condenser, 9... Drain, 43...
Inert gas drying chamber, 42... Inert gas source, 24
...Cleaning/drying tank opening end, 22, 23...Filter, 5'...Alcohol vapor generation chamber, 5''...Cleaning/drying chamber, 10...Circulation pipe.

Claims (1)

[Claims] 1 A cleaning drying tank is equipped with a heater at the bottom to form an alcohol chamber and an alcohol vapor cleaning semi-drying chamber from the bottom, and the alcohol chamber is further connected to an alcohol separation and recovery device as well as to a condensation drain device on the upper side, and the above-mentioned alcohol Further above the alcohol vapor cleaning semi-drying chamber, an inert gas drying chamber having a specific gravity lower than that of alcohol is connected to an inert gas source, and the upper end of the inert gas drying chamber is connected to the upper end of the cleaning drying tank. In the washing/drying apparatus, which is formed as an overflow type, the alcohol vapor washing semi-drying chamber is divided into an alcohol vapor generation chamber and a washing/drying chamber by a filter, and the drain of the latter and the alcohol chamber are connected by a circulation pipe. Dust-free washing and drying equipment characterized by: