JPH08927A - Filter apparatus - Google Patents

Abstract

PURPOSE:To prevent the stagnation of a chemical soln. in a filter apparatus and to also prevent the generation of dust caused by the gelation of the chemical soln. due to stagnation or the obstruction of the smooth circulation of the chemical soln. caused by stagnation. CONSTITUTION:A filter 8 is provided in a cylindrical housing 1 and a chemical soln. inlet part 4 is provided to the lower closed end of the housing while an outlet part 6 is provided to the upper closed end thereof in a tapered shape expanded in diameter toward the lower closed end of the cylindrical housing 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter device, and in particular, a filter is provided inside a tubular housing whose upper and lower ends are closed, and a chemical solution inlet is provided at the lower closed end of the tubular housing. The present invention relates to a filter device in which an outlet portion for a chemical liquid that has passed through a filter is provided at an upper closed end of a housing.

[0002]

2. Description of the Related Art For cleaning, wet etching and the like, a filter device for filtering a chemical used in the process is indispensable. This is because it is essential for effective use of the chemical liquid to filter the chemical liquid used in the treatment tank for performing the treatment and return it to the treatment layer to circulate the chemical liquid. FIG. 3 is a cross-sectional view showing an example of a conventional filter device used for filtering the chemical solution. In the figure, 1 is a cylindrical housing made of, for example, stainless steel. 2 is an upper closed end that closes the upper end of the housing 1, 3 is a lower closed end that closes the lower end of the housing 1,
Reference numeral 4 denotes an inlet portion formed at the lower closed end 3 and communicates with a pipe 5 through which a chemical solution from a processing tank (not shown) passes. An outlet 6 is formed in the upper closed end 2 and communicates with a pipe 7 for returning the chemical liquid to the processing tank.

Reference numeral 8 denotes a filter in which, for example, a fibrous filter material 10 (shown in satin) is housed in a cylindrical container 9 having a bottom. 11, 11, ... Are the above-mentioned containers 9
The liquid through holes formed in the peripheral wall of the housing allow the chemical liquid supplied into the housing 1 through the pipe 5 to pass through the liquid through holes 11, 1
1 and so on to enter the container 9. An outlet 12 is provided at the upper end of the container 9 and communicates with the outlet portion 6 of the housing 1. Reference numeral 13 denotes a drain for removing the air that has entered the housing 1. According to such a filter device, the chemical liquid that has entered the housing 1 from the treatment tank (not shown) through the pipe 5 enters the inside of the container 9 through the liquid passage windows 11, 11 ,.
While being filtered by the filter material 10, it goes up and enters the pipe 7 through the outlets 12 and 6, and is returned by the pipe 7 to a treatment tank (not shown).

The air that has entered the housing 1 is extracted by the drain 13. Although the inlet 4 is provided at the lower closed end 3 in the filter device shown in FIG. 3, the inlet 4 may be provided at the upper closed end 2 like the outlet 6. Whether the inlet portion 4 is provided at the lower closed end 3 or the upper closed end 2, the conventional filter device has a lower and upper closed ends of the housing 1 as shown in FIG. The upper and lower ends of the container 3 and 2 and the container 9 were formed flat.

[0005]

By the way, in the conventional filter device, as described above, the lower and upper closed ends 3 and 2 of the housing 1 and the upper and lower end portions of the container 9 are formed flat. However, there is a problem that the chemical solution easily stays at the corners A, A, B, B, and when staying, it gels and becomes dust. In particular, the corner A of the lower closed end 3 of the housing 1,
Retention easily occurred in A. The dust generated by the gelation of the chemical liquid due to the retention naturally becomes a contamination source of the object to be processed, for example, a semiconductor wafer, which is not preferable. Further, such retention of the chemical liquid hinders smooth circulation of the chemical liquid, which is not preferable in that respect either.

The present invention has been made to solve the above problems, and prevents the chemical solution from staying inside the filter device, which in turn causes dusting due to gelation of the chemical solution due to the stay. The purpose is to prevent the smooth circulation of the drug solution from being hindered by the retention.

[0007]

A filter device according to a first aspect of the present invention is characterized in that it is formed in a tapered shape so that the lower closed end of the cylindrical housing is expanded in diameter upward. A filter device according to a second aspect of the present invention is the filter device according to the first aspect, characterized in that the lower end portion of the filter is formed in a taper shape such that the diameter thereof increases as it goes upward.

[0008]

According to the filter device of the first aspect, since the lower closed end of the cylindrical housing is formed in a taper shape so that the diameter increases as it goes upward, the corner portion of the lower closed end of the cylindrical housing for the chemical liquid is formed. Therefore, it is possible to prevent dust from being generated due to gelation of the chemical liquid due to the retention and to prevent smooth circulation of the chemical liquid due to the retention. According to the filter device of the second aspect, since the lower end portion of the filter is formed in a taper shape such that the lower end portion has a larger diameter, the smooth flow of the chemical liquid inside the housing is not obstructed by the lower end portion of the filter. Therefore, the retention can be prevented more reliably.

[0009]

The filter device of the present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 is a sectional view showing one embodiment of the filter device of the present invention. This filter device is different from the conventional filter device shown in FIG. 3 in that the lower closed end of the cylindrical housing is expanded in diameter upward, and the upper closed end is expanded upward. Although it is greatly different in that it is formed in a taper shape, it is common in other points, and since the common points have already been described, the description thereof will be omitted and only the different points will be described. Further, common parts are denoted by common reference numerals throughout the drawings.

The upper closed end 2 of the housing 1 of the present filter device is formed in a taper shape so that the diameter becomes smaller toward the upper side, and the lower closed end 3 is formed in a taper shape so that the diameter becomes larger toward the upper side. Has been done. Therefore, according to the present filter device, there is no fear that the chemical solution will accumulate at the corners A, A, B, B inside the housing 1 as in the conventional filter device shown in FIG. Accordingly, it is possible to prevent dust from being generated due to gelation of the chemical liquid due to the retention and to prevent smooth circulation of the chemical liquid due to the retention.

FIG. 2 is a sectional view showing another embodiment of the filter device of the present invention. In the present filter device, the container 8 containing the filter material 10 is provided with a taper on the upper and lower outer portions so that the smooth flow of the chemical solution inside the housing 1 is not obstructed by the upper and lower ends of the filter 8. Therefore, according to the present filter device, retention can be prevented more reliably.

[0012]

The filter device according to the present invention is characterized in that the lower closed end of the cylindrical housing is formed in a taper shape so that the diameter increases as it goes upward. Therefore, claim 1
According to the filter device of the above, since the lower closed end of the tubular housing is formed in a taper shape such that the diameter is increased as it goes upward, the drug solution is accumulated at the corner of the lower closed end of the tubular housing. Therefore, it is possible to prevent dust from being generated due to gelation of the chemical liquid due to the retention and to prevent smooth circulation of the chemical liquid due to the retention.

A filter device according to a second aspect of the present invention is characterized in that the lower closed end of the filter is formed in a taper shape such that the diameter thereof increases as it goes upward. Therefore, according to the filter device of the second aspect, since the lower end of the filter is formed in a taper shape such that the diameter is increased as it goes upward, there is a risk that the smooth flow of the chemical liquid inside the housing is obstructed by the lower end of the filter. Therefore, the retention can be prevented more reliably.

[Brief description of drawings]

FIG. 1 is a sectional view showing one embodiment of a filter device of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the filter device of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example of a filter device.

[Explanation of symbols]

 1 housing 2 upper closed end 3 lower closed end 4 inlet 6 outlet 8 filter

Claims (2)

[Claims] 1. A filter is provided inside a tubular housing whose upper and lower ends are closed, a chemical liquid inlet is provided at a lower closed end of the tubular housing, and a filter is passed at an upper closed end of the tubular housing. A filter device characterized in that an outlet portion for the liquid medicine is provided, and the lower closed end of the cylindrical housing is formed in a taper shape so that the diameter increases as it goes upward. 2. The filter device according to claim 1, wherein at least an outer portion of a lower end portion of the filter is formed in a tapered shape such that the diameter is increased as it goes upward.