JPH07229682A - Vapor drier - Google Patents

Abstract

PURPOSE:To enable supply of clean solvent vapor onto the surface of a substance to be dried. CONSTITUTION:In a vapor drier wherein a solvent vapor atmosphere part 12 filled up with the solvent vapor is generated in a tank by heating and vaporizing a liquid solvent 2 stored in a liquid solvent storage part 11 in the lower part of the tank and a substance 6 to be dried is dried in the solvent vapor atmosphere part 12, a trap 10 catching minute droplets of the liquid solvent contained in the solvent vapor is provided between the liquid solvent storage part 11 and the solvent vapor atmosphere part 12 of the vapor drier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam drying apparatus used for drying a semiconductor device substrate or the like.

[0002]

2. Description of the Related Art FIG. 10 is a sectional view showing the structure of a conventional steam dryer. In the figure, 1 is a steam drying tank, 2 is a liquid solvent such as isopropyl alcohol serving as a steam generation source, 3 is a heater for heating the liquid solvent 2, 4 is a cooling pipe for cooling and condensing the generated steam, 5 is a liquid droplet condensed by contacting the cooling pipe 4, 6 is an object to be dried such as a semiconductor substrate, 7 is a solvent waste liquid containing water condensed on the surface of the object to be dried 6, and 8 is a solvent waste liquid 7. A liquid receiver for collecting and discharging, and a drain pipe 9.

In the vapor drying apparatus constructed as described above, when the heater 3 heats the liquid solvent 2 to generate vapor, the vapor fills the vapor drying tank 1 and rises while forming a vapor atmosphere portion. , Is condensed upon contact with the cooling pipe 4, and returns to the liquid solvent 2 in the state of droplets 5. Then, when the article 6 to be dried after washing with water is inserted into the vapor atmosphere portion formed as described above, the solvent vapor is condensed on the surface of the article 6 to be dried and mixed with the moisture adhering to the article 6 to be dried. The solvent waste liquid 7 is collected by the liquid receiver 8 and discharged through the waste liquid pipe 9. In this way, when the surface of the material to be dried 6 is completely depleted of water, the material to be dried 6 is taken out of the tank.

[0004]

Since the conventional vapor dryer is constructed as described above, the heater 3 is heated to a temperature higher than the boiling point of the liquid solvent 2 in order to supply sufficient solvent vapor to the material 6 to be dried. When the heating temperature is set, the solvent vapor and the minute droplets of the liquid solvent 2 are supplied to the surface of the material to be dried 6 in a mixed state. At this time, if the liquid solvent 2 contains impurities such as metal, the impurities are contained in the minute droplets and supplied to the surface of the article to be dried 6 to deteriorate the performance of the article to be dried 6. There was a problem. In addition, since the liquid droplets 5 condensed in the cooling pipe 4 are returned to the liquid solvent 2 in the lower part of the vapor drying tank 1, the water concentration in the solvent is increased, which causes a drying failure of the material 6 to be dried. There was also.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a vapor drying apparatus capable of supplying clean solvent vapor to the surface of an object to be dried.

[0006]

[Means for Solving the Problems] Claim 1 according to the present invention
The vapor drying device is provided with a trap between the liquid storage section in the tank and the vapor atmosphere section filled with the solvent vapor.

The steam drying apparatus according to a second aspect of the present invention is provided with a trap between the liquid storage section and the vapor atmosphere section in the tank and a heating means for heating the trap.

The vapor drying apparatus according to a third aspect of the present invention is provided with a tank for recovering the second liquid solvent condensed and liquefied after the drying treatment of the material to be dried, and the second tank is provided in the tank. A specific resistance meter for measuring the specific resistance of the liquid solvent is provided.

Further, the steam drying apparatus according to a fourth aspect of the present invention is provided with a tank for recovering the second liquid solvent condensed and liquefied after the drying treatment of the material to be dried, and the second tank in the tank. A specific resistance meter for measuring the specific resistance of the liquid solvent is provided, the water concentration of the second liquid solvent is judged based on the measured value of the specific resistance meter, and when the water concentration is lower than a predetermined value, the second The liquid solvent recovery means for recovering the liquid solvent of (1) is collected in the liquid storage section in the lower part of the tank.

[0010]

The trap of the vapor drying apparatus according to the first aspect of the present invention captures minute droplets generated from the heated and boiled liquid solvent, and prevents them from adhering to the surface of the material to be dried.

Further, the trap heating means of the vapor drying apparatus according to the second aspect of the present invention heats the trap to a temperature not lower than the boiling point of the liquid solvent to prevent condensation of the solvent vapor.

Further, the resistivity meter provided in the tank of the steam drying apparatus according to claim 3 measures the resistivity of the second liquid solvent collected in the tank and includes it in the second liquid solvent. Detect the water concentration that is generated.

Further, the liquid solvent recovery means of the vapor drying apparatus according to the fourth aspect measures the specific resistance of the second liquid solvent recovered in the tank, and the second liquid solvent of the second liquid solvent is measured based on the measured value. The water concentration is determined, and when the water concentration is lower than a predetermined value, the liquid solvent in the tank is recovered into the tank.

[0014]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing a structure of a steam drying apparatus according to a first embodiment of the present invention, FIG. 2 is a plan view showing a structure of a trap shown in FIG. 1, and FIG. 3 is a sectional view taken along line III-III in FIG. . In the figure, the same parts as those of the conventional one are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 10 denotes a trap, which is provided between the liquid solvent storage portion 11 and the solvent vapor atmosphere portion 12, and the trap 10 has a mesh plate as shown in FIGS. 2 and 3.

In the vapor drying apparatus according to the first embodiment configured as described above, the minute droplets contained in the vapor generated from the heated and boiling liquid solvent 2 are captured and separated in the narrow gap of the trap 10, and at the same time. Since the impurities contained in the minute droplets are also captured, only the clean solvent vapor is supplied to the surface of the material to be dried 6, and the surface of the material to be dried 6 is dried while maintaining its performance. Play.

Example 2. In the first embodiment,
Although the case where the trap 10 is composed of a mesh plate has been described, the trap plate 10 is not limited to the mesh plate, and two metal plates 14 provided with a large number of small holes 13 as shown in FIGS. 4 and 5 are used.
May be provided so as to face each other by shifting by 1/2 pitch, and the same effect as that of the above-described first embodiment is exhibited.

Embodiment 3. In addition, in the second embodiment, two metal plates 14 provided with a large number of small holes 13 are used,
Trap 1 with small holes 13 offset by 1/2 pitch and facing each other
However, as shown in FIGS. 6 and 7, a large number of partition plates 15 may be arranged at equal intervals and obliquely. It has the same effect.

Example 4. FIG. 8 is a sectional view showing the structure of the steam drying apparatus according to the fourth embodiment of the present invention. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 16 is a heater for heating 10 parts of the trap. Although the heater 16 is provided outside the steam drying tank 1 in the drawing, it may be provided inside the tank.

In the vapor drying apparatus according to the fourth embodiment configured as described above, not only the minute droplets contained in the vapor generated from the heated and boiling liquid solvent 2 are separated by the trap 10, but also the trap 10 is removed. By heating to a temperature equal to or higher than the boiling point of the liquid solvent 2, the generated solvent vapor is cooled and condensed in the trap 10 and is not consumed, and there is an effect of maintaining a vapor atmosphere that is clean and sufficient for drying.

Example 5. FIG. 9 is a sectional view showing the structure of the steam drying apparatus according to the fifth embodiment of the present invention. In the figure, the same parts as those in the first and fourth embodiments are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 17 is a liquid receiver for recovering the second liquid solvent condensed in the cooling pipe 4, 18 is a recovery tank for storing the second liquid solvent recovered in the liquid receiver 17 through a pipe 19, and 20 is a recovery tank. A specific resistance meter provided in the tank 18, and measures the specific resistance of the second liquid solvent stored in the recovery tank 18. Reference numeral 21 denotes a control unit, which determines the water concentration of the second liquid solvent based on the measured value of the resistivity meter 20 and transmits a signal based on this determination to the switching valve 22 to operate the switching valve 22. That is, the resistivity meter 20, the control unit 21, the switching valve 22
The liquid solvent recovery means 23 is constituted by. 24
Is a drainage pipe, and 25 is a return pipe.

In the vapor drying apparatus according to the fifth embodiment having the above-described structure, the solvent vapor after drying the material 6 to be dried is brought into contact with the cooling pipe 4 and cooled to become the condensate 5 in the liquid receiver 17. It is recovered and stored in the recovery tank 18 through the pipe 19. The specific resistance of the second liquid solvent collected here is measured by the specific resistance meter 20, the measured value is sent to the control unit 21, and the concentration of the water contained in the second liquid solvent is determined and controlled. Switching valve 22 according to a command from the section 21
Works. That is, when the water concentration of the second liquid solvent in the recovery tank 18 is lower than the predetermined value, it is recovered and reused in the vapor drying tank 1 through the return pipe 25, and when the water concentration is higher than the predetermined value, it is discharged. Since it is discharged through the liquid pipe 24, there is an effect that the inside of the steam drying tank 1 is always stable and a highly accurate drying process is achieved.

[0022]

As described above, according to the first aspect of the present invention, since the trap is provided between the liquid storage section and the vapor atmosphere section in the tank, the trap is generated from the liquid solvent heated and boiled. It is possible to provide a vapor drying apparatus capable of capturing fine droplets of water and supplying only clean solvent vapor to the surface of an object to be dried.

According to the second aspect of the present invention, since the trap is provided between the liquid storage section and the vapor atmosphere section in the tank and the heating means for heating the trap is provided, the trap section for the solvent vapor is provided. It is of course possible to provide a vapor drying apparatus capable of preventing condensation in the above and supplying only clean solvent vapor, and maintaining a vapor atmosphere sufficient for drying.

According to a third aspect of the present invention, a tank for recovering the second liquid solvent condensed and liquefied after the drying process is provided, and the specific resistance of the second liquid solvent is stored in the tank. Since the specific resistance meter for measurement is provided, it is possible to provide the vapor drying device capable of monitoring the water concentration of the second liquid solvent.

According to a fourth aspect of the present invention, a tank for collecting the second liquid solvent condensed and liquefied after the drying process is provided, and the specific resistance of the second liquid solvent is measured in the tank. Is provided, and the water concentration of the second liquid solvent is determined based on the measured value of this resistivity meter. When the water concentration is lower than a predetermined value, the second liquid solvent is placed in the lower part of the tank. Since the liquid solvent recovery means for recovering the liquid solvent is provided in the liquid storage section, it is possible to reuse only the high quality liquid solvent, and it is possible to provide the vapor drying apparatus capable of always performing the stable drying process.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a steam dryer according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the structure of the trap in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a plan view showing the structure of a trap applied to a steam drying device according to a second embodiment of the present invention.

5 is a cross-sectional view taken along the line VV in FIG.

FIG. 6 is a plan view showing the structure of a trap applied to a steam drying apparatus according to Embodiment 3 of the present invention.

7 is a cross-sectional view taken along the line VII-VII in FIG.

FIG. 8 is a sectional view showing a structure of a steam drying device according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the structure of a steam dryer according to a fifth embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a configuration of a conventional steam drying device.

[Explanation of symbols]

 1 Vapor Drying Tank 2 Liquid Solvent 3 Heater 4 Cooling Coil 6 Dried Material 7 Liquid Receiving 9 Drainage Pipe 10 Trap 11 Liquid Solvent Storage 12 Solvent Vapor Atmosphere 16 Heater 18 Recovery Tank 20 Resistivity Meter 21 Control Part 22 Switching valve 23 Liquid solvent recovery means

Claims (4)

[Claims] 1. A vapor for heating and evaporating a liquid solvent stored in a liquid storage section in a tank to generate a vapor atmosphere section filled with solvent vapor in the tank, and drying an object to be dried in the vapor atmosphere section. A vapor drying apparatus, characterized in that, in the drying apparatus, a trap is provided between the liquid storage section and the vapor atmosphere section to capture minute droplets of the liquid solvent mixed with the solvent vapor. 2. A vapor for heating and evaporating a liquid solvent stored in a liquid storage section in a tank to generate a vapor atmosphere section filled with solvent vapor in the tank, and drying an object to be dried in the vapor atmosphere section. In the drying device, a trap for capturing minute droplets of the liquid solvent mixed with the solvent vapor is provided between the liquid storage section and the vapor atmosphere section, and a heating means for heating the trap is provided. And steam dryer. 3. A vapor for heating and evaporating a liquid solvent stored in a liquid storage portion in a tank to generate a vapor atmosphere portion filled with solvent vapor in the tank, and drying an object to be dried in the vapor atmosphere portion. The drying device is provided with a tank for collecting the second liquid solvent condensed and liquefied after the drying process, and a specific resistance meter for measuring the specific resistance of the second liquid solvent is provided in the tank. And steam dryer. 4. A vapor for heating and evaporating a liquid solvent stored in a liquid storage section in a tank to generate a vapor atmosphere section filled with solvent vapor in the tank, and drying an object to be dried in the vapor atmosphere section. The drying apparatus is provided with a tank for recovering the second liquid solvent condensed and liquefied after the drying process, and a specific resistance meter for measuring the specific resistance of the second liquid solvent is provided in the tank. Liquid solvent recovery for determining the water concentration of the second liquid solvent based on the measurement value of the meter and recovering the second liquid solvent in the liquid storage section in the tank when the water concentration is lower than a predetermined value. A steam drying apparatus, characterized in that means is provided.