U.S. patent application number 09/746303 was filed with the patent office on 2002-06-27 for flow control valve incorporating an inflatable bag.
This patent application is currently assigned to Taiwan Semiconductor Manufacturing Co., Ltd.. Invention is credited to Chen, Wei-Chuan.
Application Number | 20020079470 09/746303 |
Document ID | / |
Family ID | 25000262 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020079470 |
Kind Code |
A1 |
Chen, Wei-Chuan |
June 27, 2002 |
FLOW CONTROL VALVE INCORPORATING AN INFLATABLE BAG
Abstract
A flow control valve which does not utilize any moving
components in the valve is disclosed. In the flow control valve, a
valve housing that has a cylindrical-shaped wall is first provided.
Inside the valve housing, is then provided a first and a second end
plate for sealingly engaging an inner periphery of the valve
housing. The first and the second end plate are positioned
spaced-apart in a predetermined distance while each of the end
plates has at least one aperture therethrough for the passage of a
fluid flow to be controlled. Inside a valve cavity formed between
the two end plates and the inner periphery of the valve housing is
positioned an inflatable bag such that when a fluid is flown into
the inflatable bag, the bag inflates to either partially block or
completely block the fluid passageway through the valve cavity.
Inventors: |
Chen, Wei-Chuan; (Hsin Chui,
TW) |
Correspondence
Address: |
TUNG & ASSOCIATES
Suite 120
838 W. Long Lake Road
Bloomfield Hills
MI
48302
US
|
Assignee: |
Taiwan Semiconductor Manufacturing
Co., Ltd.
|
Family ID: |
25000262 |
Appl. No.: |
09/746303 |
Filed: |
December 22, 2000 |
Current U.S.
Class: |
251/61.1 ;
137/625.3; 138/46; 138/93; 251/121; 251/205 |
Current CPC
Class: |
Y10T 137/86734 20150401;
F16K 7/10 20130101 |
Class at
Publication: |
251/61.1 ;
251/121; 251/205; 137/625.3; 138/93; 138/46 |
International
Class: |
F16K 031/126 |
Claims
1. A flow control valve comprising: a valve housing having a
cylindrical-shaped wall; a first and a second end plate sealingly
engaging an inner periphery of and positioned spaced-apart in said
valve housing, each of said two end plates having at least one
aperture therethrough; a valve cavity formed in-between said two
end plates and an inner periphery of said valve housing defining a
fluid passageway therein; and an inflatable bag positioned inside
said valve cavity in fluid communication with a fluid inlet tube
such that when a fluid is flown through said fluid inlet tube into
said inflatable bag, said bag inflates to partially block or
completely block said fluid passageway in said vale cavity.
2. A flow control valve according to claim 1, wherein said
inflatable bag being fabricated of a corrosion-resistant
elastomer.
3. A flow control valve according to claim 1, wherein said
inflatable bag being fabricated of an elastomer that comprises
fluorosilicon.
4. A flow control valve according to claim 1, wherein said valve
housing being fabricated of a corrosion-resistant material.
5. A flow control valve according to claim 1, wherein said valve
housing being fabricated of stainless steel.
6. A flow control valve according to claim 1, wherein said first
and second end plates have a plurality of apertures therethrough
each having a diameter less than 1 cm.
7. A flow control valve according to claim 1, wherein said valve
housing further comprises an inlet and an outlet each adapted for
connecting to a fluid conduit.
8. A flow control valve according to claim 1, wherein said valve
housing further comprises an inlet and an outlet each equipped with
a quick-connect-disconnect fitting.
9. A flow control valve according to claim 1, wherein said fluid
inlet tube penetrates through one of said two end plates for
inflating said inflatable bag.
10. A flow control valve according to claim 1, wherein said fluid
inlet tube penetrates through one of said two end plates and said
cylindrical-shaped wall of the valve housing for feeding a fluid
into said inflatable bag.
11. A flow control valve according to claim 1, wherein said
cylindrical-shaped wall of the valve housing having a diameter
between about 1 cm and about 10 cm.
12. A flow control valve according to claim 1, wherein said
inflatable bag being inflated by a fluid selected from the group
consisting of N.sub.2, air, water and oil.
13. A flow control valve according to claim 1, wherein said
inflatable bag being inflated by N.sub.2 to a pressure inside the
inflatable bag between about 0.5 Kg/cm.sup.2 and about 25
Kg/cm.sup.2.
14. A flow control valve according to claim 1, wherein said at
least one aperture having a diameter between about 0.1 cm and about
1 cm.
15. A flow control valve according to claim 1, wherein said
cylindrical-shaped wall of the valve housing having a diameter of
at least 2 cm and said first and second end plates being positioned
spaced-apart by at least 2 cm.
16. A flow control vale incorporating an inflatable bag therein
comprising: a tubular-shaped valve housing having an inlet end and
an outlet end; two end plates positioned perpendicular to and
spaced-apart in said vale housing defining a cavity
therein-between, each of said end plates being provided with a
plurality of apertures; and an inflatable bag positioned inside
said cavity, said bag does not substantially block a fluid flow
path in said cavity when deflated but blocks said fluid flow path
completely when inflated by a fluid medium flown into said bag
through an inlet tube.
17. A flow control valve incorporating an inflatable bag therein
according to claim 16, wherein said plurality of apertures each
having a diameter between about 0.1 cm and about 1 cm.
18. A flow control valve incorporating an inflatable bag therein
according to claim 16, wherein said tubular-shaped valve housing
and said two end plates being fabricated of a corrosion-resistant
material.
19. A flow control valve incorporating an inflatable bag therein
according to claim 16, wherein said inflatable bag being fabricated
of a corrosion-resistant elastomer.
20. A flow control valve incorporating an inflatable bag therein
according to claim 16, wherein said fluid medium used in inflating
said inflatable bag being selected from the group consisting of
N.sub.2, air, water and oil.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to a flow control
valve and more particularly, relates to a flow control valve that
contains no moving parts other than an inflatable bag positioned in
a cavity of the valve.
BACKGROUND OF THE INVENTION
[0002] In a manufacturing facility, various chemicals in gaseous
and liquid form are used in various fabrication processes. For
instance, in a semiconductor fabrication plant, a semi-conducting
substrate must be processed in a multiplicity of manufacturing
steps, i.e., as many as several hundred in order to complete an
integrated circuit chip. The multiplicity of manufacturing steps
may include cleaning, cooling, deposition, etching and any other
necessary processing steps. A variety of chemicals, including
liquids and gases must be used in these steps. For instance, to
clean or cool a process chamber or a wafer platform, to etch a
specific feature on a substrate, to clean after each etching or
deposition steps, to deposit layers of materials on a substrate, or
to carry out any other processes.
[0003] The variety of chemicals used in a semiconductor facility
must be handled with care since some of the processing chemicals
are highly toxic and/or highly corrosive. For instance, strong
acids are frequently used in an etcher for the etching of metals
for forming a conductive path. Since hazardous materials are not
always all consumed in chemical processes, unused hazardous
chemicals must be recycled or otherwise disposed of. Due to their
hazardous nature, the materials must be carefully handled during
their storage and transportation to avoid personal injuries and
potential fire hazard. The mechanical components used in
transporting these materials should therefore be minimized such
that potential exposure of personnel to the chemicals may be
reduced.
[0004] Since a large number of chemicals utilized in a
semiconductor fabrication facility are of the flammable or toxic
nature, i.e., other than those inert gases normally utilized as
purge or carrier gases, the storage and transporting of such
chemicals are important aspects in the management of a fabrication
facility. For instance, to avoid fire, explosion and serious
personal injuries, a flammable or toxic gas must be securely stored
in a safe storage facility. The storage of these gases is usually
kept away from the plant personnel and thus, away from the
processing equipment where they will be used. The transporting or
delivery of these gases to a processing equipment therefore becomes
another important aspect in the management of a fabrication
plant.
[0005] A typical gas delivery system utilized in a semiconductor
fabrication facility is shown in FIG. 1. The system 10 includes a
main process gas input line 12 and a main purge gas supply line 14.
A process gas, after being fed into the main process gas input line
12, is transported through a two-way air actuated valve 16 into a
main process gas supply line 18. Off the main process gas supply
line 18, a number of two-way, diaphragm-type (hereinafter,
diaphragm) control valves 20 are utilized to feed the process gas
from the main supply line 18 into a three-way diaphragm control
valve 24. Into the three-way diaphragm control valve 24, a purge
gas is also fed from the main purge gas supply line 26 into a
second gas inlet 28 of the three-way diaphragm control valve 24.
The purge gas, i.e., an inert gas, fed through the inlet 28 is then
mixed with the process gas fed through the inlet 22 and outputted
from outlet 32 of the three-way diaphragm control valve 24. It
should be noted that in the above example, the purge gas is
utilized as a carrier gas for the process gas. The purge gas may
also be used alone for purging the gas line without the process
gas. In such application, the three-way diaphragm control valve is
adjusted such that only inlet 28 is connected to outlet 32 of the
valve, while inlet 22 is shut-off.
[0006] When the purge gas is used as a carrier gas, the gas mixture
is sent through a gas pressure regulator 36, a pressure transducer
38 into a second three-way diaphragm control valve 42 through inlet
40. The process gas/carrier gas mixture then exits from either
outlet 46 or 48 and is fed into a process equipment. It should be
noted that in FIG. 1, the process equipment and the gas lines
feeding to the process equipment are not shown for simplicity
reasons. When the gas outlets 46, 48 are not connected to a process
equipment or to a gas delivery line, the outlets 46, 48 are capped
by a cap 50. In the gas distribution system 10 shown in FIG. 1, the
main process gas input line 18 is further provided with an
expansion valve 60. The expansion valve 60 is provided such that
other gas output lines may be connected thereto allowing future
expansion of processing equipment in the fab facility. The outlets
62, 64 are also capped by caps 66 when the expansion valve 60 is
not in use for add-on additional gas supply lines.
[0007] In the gas distribution system 10, it is seen that a number
of two-way or three-way diaphragm-type control valves, i.e., 20, 24
and 42 are utilized for controlling the flow of various gases,
including those of the flammable or toxic nature or vacuum in the
supply lines. The control valves are equipped with control handles
mounted on top of the valves such that a handle may be turned
either clockwise or counterclockwise to close or open the gas
passage.
[0008] FIG. 1A illustrates a cross-sectional view of an automated
diaphragm valve 26 without the manually operated handle. It is seen
that the diaphragm valve 26 is constructed with several moving
parts, for instance, a spring 30, a control diaphragm 34, a spindle
44 and a sealing diaphragm 52. Any of the moving parts 30, 34, 44
and 52 may fail during the operation of the valve 26 and therefore
cause serious problems for the fluid supply system 10. It is
therefore desirable to provide a flow control valve for controlling
fluid used in semiconductor fabrication that is essentially without
any moving parts and therefore is more reliable in operation.
[0009] It is therefore an object of the present invention to
provide a flow control valve that does not have the drawbacks or
shortcomings of the conventional flow control valves.
[0010] It is another object of the present invention to provide a
flow control valve that utilizes a minimum number of moving parts
inside the valve.
[0011] It is a further object of the present invention to provide a
flow control valve that can be advantageously used in semiconductor
fabrication processes.
[0012] It is another further object of the present invention to
provide a flow control valve that does not utilize any moving
parts.
[0013] It is still another object of the present invention to
provide a flow control valve for use in semiconductor manufacturing
by utilizing an inflatable bag in a cavity of the valve.
[0014] It is yet another object of the present invention to provide
a flow control valve by enclosing in a cavity formed by two end
plates in a cylindrical-shaped housing and providing apertures in
the end plates and an inflatable bag in the cavity.
[0015] It is still another further object of the present invention
to provide a flow control valve that incorporates an inflatable bag
wherein the bag does not substantially block a fluid flow
passageway in the cavity of the valve when deflated but blocks the
fluid flow passageway completely when inflated.
[0016] It is yet another further object of the present invention to
provide a flow control valve incorporating an inflatable bag
wherein the bag may be inflated by N.sub.2, air, water or oil.
SUMMARY OF THE INVENTION
[0017] In accordance with the present invention, a flow control
valve for use in a fluid flow supply system that does not contain
moving parts in relation to the valve housing is disclosed.
[0018] In a preferred embodiment, a flow control valve is provided
which includes a valve housing that has a cylindrical-shaped wall,
a first and a second end plate sealingly engaging an inner
periphery of and positioned spaced-apart in the valve housing, each
of the two end plates has at least one aperture therethrough; a
valve cavity formed in-between the two end plates and an inner
periphery of the valve housing defining a fluid passageway therein;
and an inflatable bag positioned inside the valve cavity in fluid
communication with a fluid inlet tube such that when a fluid is
flown through the fluid inlet tube into the inflatable bag, the bag
inflates to partially block or completely block the fluid
passageway in the valve cavity.
[0019] In the flow control valve, the inflatable bag may be
fabricated of a corrosion-resistant elastomer, or fabricated of an
elastomer that comprises fluorosilicon. The valve housing may be
fabricated of a corrosion-resistant material or stainless steel.
The first and the second plate may have a plurality of apertures
therethrough each has a diameter less than 1 cm. The valve housing
may further include an inlet and an outlet each adapted for
connecting to a fluid conduit, or an inlet and an outlet each
equipped with a quick-connect-disconnect fitting. The fluid inlet
tube penetrates through one of the two end plates for inflating the
inflatable bag, or the fluid inlet tube penetrates through one of
the two end plates and the cylindrical-shaped wall of the valve
housing for feeding a fluid into the inflatable bag. The
cylindrical-shaped wall of the valve housing may have a diameter
between about 1 cm and about 10 cm. The inflatable bag may be
inflated by a fluid selected from the group consisting of N.sub.2,
air, water and oil. The inflatable bag may be inflated by N.sub.2
to a pressure inside the inflatable bag between about 0.5
Kg/cm.sup.2 and about 25 Kg/cm.sup.2. The at least one aperture may
have a diameter between about 0.1 cm and about 1 cm. The
cylindrical-shaped wall of the valve housing may have a diameter of
at least 2 cm and the first and second end plates being positioned
spaced-apart by at least 2 cm.
[0020] The present invention is further directed to a flow control
valve which incorporates an inflatable bag therein that is
constructed by a tubular-shaped valve housing that has an inlet end
and an outlet end; two end plates positioned perpendicular to and
space-apart in the valve housing defining a cavity therein-between,
each of the end plates may be provided with a plurality of
apertures; and an inflatable bag positioned inside the cavity, the
bag does not substantially block a fluid flow path in the cavity
when deflated, but blocks the fluid flow path completely when
inflated by a fluid medium flown into the bag through an inlet
tube.
[0021] In the flow control valve incorporating an inflatable bag
therein, the plurality of apertures may each have a diameter
between about 0.1 cm and about 1 cm. The tubular-shaped valve
housing and the two end plates may be fabricated of a
corrosion-resistant material. The inflatable bag may be fabricated
of a corrosion-resistant elastomer. The fluid medium used in
inflating the inflatable bag may be selected from the group
consisting of N.sub.2, air, water and oil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects, features and advantages of the
present invention will become apparent from the following detailed
description and the appended drawings in which:
[0023] FIG. 1 is a graph illustrating a conventional fluid flow
control system utilizing diaphragm flow control valves.
[0024] FIG. 1A is a cross-sectional view of an air-operated
diaphragm-type flow control valve.
[0025] FIG. 2A is a cross-sectional view of a present invention
flow control valve incorporating an inflatable bag in the cavity of
the valve.
[0026] FIG. 2B is a plane view of an end plate utilized in the
present invention flow control valve.
[0027] FIG. 3 is a cross-sectional view of the present invention
flow control valve with the inflatable bag in a fully inflated
condition.
[0028] FIG. 4 is a graph illustrating the dependency of an air
pressure in the inflatable bag on the diameter of the bag.
[0029] FIG. 5 is a graph illustrating the dependency of a fluid
flow rate through the flow control valve on the pressure in the
inflatable bag.
[0030] FIG. 6A-6D are implementation examples for utilizing the
present invention flow control valve incorporating an inflatable
bag.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] The present invention discloses a flow control valve that is
not constructed by any moving parts but instead, incorporates an
inflatable bag in a cavity of the valve. The present invention flow
control valve, while is applicable to any fluid control situation,
is particularly suited in controlling fluid flow in microelectronic
fabrication processes.
[0032] The present invention flow control valve can be
advantageously constructed by a valve housing that has a
cylindrical-shaped sidewall; a first and a second end plate for
sealingly engaging an inner periphery of the cylindrical-shaped
wall wherein the end plates are positioned spaced-apart, each of
the two end plates has at least one aperture therethrough for the
passage of a fluid flow to be controlled; a valve cavity formed
in-between the two end plates and an inner periphery of the valve
housing defining a fluid passageway therein; and an inflatable bag
positioned inside the valve cavity in fluid communication with a
fluid inlet tube such that when a fluid is flown through the fluid
inlet tube into the inflatable bag, the bag inflates to partially
block or completely block the fluid passageway in the valve
cavity.
[0033] The present invention further discloses a flow control valve
which does not contain any moving components in relation to other
parts of the valve, but instead, only contains an inflatable bag
that inflates and moves against itself. The valve is constructed by
a tubular-shaped valve housing which has an inlet end and an outlet
end adapted for connecting to fluid conduits. The inlet end and the
outlet end may further be provided with a quick-connect/disconnect
fitting for easier assembly or disassembly of the fluid control
valve in a fluid flow control system. The inflatable bag, which is
positioned inside a cavity of the valve housing, may be inflated to
any desirable pressure and therefore to any desirable volume to
either partially or completely block a fluid flow passageway
through the cavity of the valve. Suitable fluid medium such as
N.sub.2, air, water and oil may be used to inflate the inflatable
bag of the present invention flow control valve.
[0034] In general, the flow control valve of the present invention
should be fabricated of a corrosion-resistant material such that
the flow control valve can be used to control the flow of any
fluid, particularly including those toxic or corrosive fluids
frequently used in semiconductor fabrication processing.
[0035] Referring now to FIG. 2A, wherein a cross-sectional view of
a present invention flow control valve 70 is shown. Flow control
valve 70 is constructed by a cylindrical-shaped wall 72, or a
tubular-shaped wall. A first end plate 74 and a second end plate 76
are positioned inside the valve housing 72 in a perpendicular
relationship to the sidewall of the valve housing. The first end
plate 74 and the second end plate 76 are further positioned at a
predetermined, spaced-apart relationship. In the first and second
end plates 74, 76, as shown in a plane view in FIG. 2B, a plurality
of apertures 78 is provided. It should be noted that any suitable
combination, for instance of one aperture or more, may be utilized
depending on the specific control requirement and the environment
in which the flow control valve is operated. For instance, a
suitable number of the plurality of apertures 78 may be, as shown
in FIG. 2B, seven apertures each having a diameter in-between about
0.1 cm and about 1 cm. The word "about" used in this writing
indicates a range of .+-.10% from the average value given.
[0036] The valve housing 72 of cylindrical-shape may be fabricated
of a corrosion-resistant material, for instance, of stainless steel
or teflon. The end plates 74, 76 are further fabricated of a
corrosion-resistant material such as stainless steel, teflon or any
other corrosion-resistant polymeric material such that any fluid
flow may be used in the present invention novel flow control valve
70.
[0037] Into a cavity 80 of the valve housing 72, defined by the two
end plates 74, 76 and an interior surface 82 of the
cylindrical-shaped wall, is positioned an inflatable bag 90 that is
also fabricated of a resilient, corrosion-resistant material. While
any resilient, corrosion-resistant elastomeric material may be
suitable, a fluorosilicon elastomer was used in producing the
inflatable bag used in the preferred embodiment. The inflatable bag
90 may have an inlet 92 which is connected to a fluid inlet tube 84
for feeding a fluid medium such as N.sub.2, air, water and oil into
the inflatable bag 90. It should be noted that the fluid inlet tube
84 penetrates through the end plate 74 and the valve housing
72.
[0038] When a fluid medium is flown into the inflatable bag 90 and
therefore fully inflates the bag, as shown in FIG. 3, the inflated
bag 96 completely blocks the fluid passageway provided in cavity 80
of the flow control valve 70. It is seen in FIG. 3, all the
apertures 78 in the end plates 74, 76 are blocked by a wall of the
inflatable bag 90. In the condition shown in FIG. 3, the fluid
passageway in the cavity 80 of the valve housing 72 is completely
blocked and therefore the flow control valve acts as an on/off
valve to either completely open or completely block the fluid
passageway. However, it should be noted that, the present invention
novel flow control valve may also be used to partially block the
fluid passageway in the valve housing such that a suitable flow
rate of the fluid flow can be adjusted. This is shown in FIG. 5,
wherein a fluid flow rate through the cavity 80 of the valve
housing 72 decreases from about 100 cm.sup.2/min. to about 0
cm.sup.2/min. in-between a bag inflation pressure of about 1.0
Kg/cm.sup.2 and about 1.35 Kg/cm.sup.2.
[0039] A graph illustrating the air pressure in Kg/cm.sup.2 in the
inflatable bag 90 versus the diameter of the bag in centimeters is
shown in FIG. 4. When the inflatable bag 90 is fully inflated to a
diameter of about 3 cm, which is the internal diameter of the
cylindrical-shaped wall of the valve housing 72, the air pressure
in the inflatable bag is about 6 Kg/cm.sup.2. The dependency of the
air pressure in the bag on the diameter of the bag depends on other
parameters such as the type of the elastomeric material and the
thickness of the inflatable bag. The data shown in FIGS. 4 and 5
was obtained on inflatable bag fabricated of a fluorosilicon
elastomer in the present invention preferred embodiment.
[0040] In the preferred embodiment, a suitable diameter of the
valve housing of about 1.25 inch is utilized, while a suitable
distance between the two end plates is also about 1.25 inches. Any
other suitable dimension, such as an internal diameter of the valve
housing between about 1 cm and about 10 cm may be utilized. The
distance between the end plates may be similar to the diameter of
the valve housing.
[0041] A series of four implementation examples are shown in FIGS.
6A, 6B, 6C and 6D. FIG. 6A indicates an application of the present
invention novel flow control valve used as an on/off switch wherein
a fluid source is provided to an inlet end 86 of the flow control
valve 88 which is equipped with an inflatable bag (not shown). When
the inflatable bag is in a deflated condition, fluid flows through
the flow control valve 88 from the outlet end 94 controlled by a
signal source 98. The valve 88 is therefore being used as an on/off
switch for the fluid flow.
[0042] FIG. 6B illustrates another implementation example of the
present invention flow control valve 88 wherein a pressure adjustor
100 and a controller 102 are provided. In this example, a flow rate
command is first inputted to the controller 102, a signal source
pressure and a bag volume relationship equation is then compared to
a detected value by the pressure sensor 104. The volume of the
inflatable bag is then changed accordingly by changing the pressure
in the bag until the output from the outlet end 94 equals to the
preset, desirable flow rate.
[0043] In the third implementation example shown in FIG. 6C, a
series of the present invention flow control valves 104, 106, 108,
110 and 112 are utilized for controlling a fluid flow from the
source 86. For instance, when C1 is on, the source D1 is also on.
When C2 is on, the source D2 is also on. When C1 is off, the source
D1 is also off. When C2 is off, the source D2 is also off. Similar
relationship on the other flow control valves may be similarly
derived.
[0044] Another implementation example of a mixer of fluid flows is
shown in FIG. 6D, wherein a mixture exits the outlet 94 may be
achieved. Each fluid flow component 120, 122, 124, 126 and 128 may
be fed in and controlled by the individual flow control valves 104,
106, 108, 110 and 112.
[0045] The present invention novel flow control valve and various
implementation examples for utilizing the valve have therefore been
amply described in the above description and in the appended
drawings of FIGS. 2A.about.6D.
[0046] While the present invention has been described in an
illustrative manner, it should be understood that the terminology
used is intended to be in a nature of words of description rather
than of limitation.
[0047] Furthermore, while the present invention has been described
in terms of a preferred embodiment, it is to be appreciated that
those skilled in the art will readily apply these teachings to
other possible variations of the inventions.
[0048] The embodiment of the invention in which an exclusive
property or privilege is claimed are defined as follows.
* * * * *