U.S. patent application number 15/900033 was filed with the patent office on 2018-06-28 for anti-spike pressure management of pressure-regulated fluid storage and delivery vessels.
The applicant listed for this patent is Entegris, Inc.. Invention is credited to Gregory Scott Baumgart, Barry Lewis Chambers, Joseph R. Despres, Matthew B. Donatucci, Edward E. Jones, Chiranjeevi Pydi, Edward A. Sturm, Joseph D. Sweeney.
Application Number | 20180180225 15/900033 |
Document ID | / |
Family ID | 50341988 |
Filed Date | 2018-06-28 |
United States Patent
Application |
20180180225 |
Kind Code |
A1 |
Despres; Joseph R. ; et
al. |
June 28, 2018 |
ANTI-SPIKE PRESSURE MANAGEMENT OF PRESSURE-REGULATED FLUID STORAGE
AND DELIVERY VESSELS
Abstract
A fluid supply package comprising a pressure-regulated fluid
storage and dispensing vessel, a valve head adapted for dispensing
of fluid from the vessel, and an anti-pressure spike assembly
adapted to combat pressure spiking in flow of fluid at inception of
fluid dispensing.
Inventors: |
Despres; Joseph R.;
(Middletown, CT) ; Sweeney; Joseph D.; (New
Milford, CT) ; Jones; Edward E.; (Woodbury, CT)
; Donatucci; Matthew B.; (Bethel, CT) ; Pydi;
Chiranjeevi; (Danbury, CT) ; Sturm; Edward A.;
(New Milford, CT) ; Chambers; Barry Lewis;
(Midlothian, VA) ; Baumgart; Gregory Scott; (New
Fairfield, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Entegris, Inc. |
Billerica |
MA |
US |
|
|
Family ID: |
50341988 |
Appl. No.: |
15/900033 |
Filed: |
February 20, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14430105 |
Mar 20, 2015 |
9897257 |
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PCT/US13/61059 |
Sep 20, 2013 |
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15900033 |
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61704402 |
Sep 21, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F17C 2205/0344 20130101;
F17C 2201/0104 20130101; F17C 2250/0626 20130101; F17C 2270/0518
20130101; F17C 2205/0391 20130101; F17C 2221/016 20130101; F17C
13/04 20130101; F17C 2221/015 20130101; F17C 2205/035 20130101;
Y02E 60/32 20130101; F17C 2221/013 20130101; F17C 13/12 20130101;
F17C 2205/0326 20130101; F17C 2205/0329 20130101; F17C 2205/0382
20130101; Y10T 137/7795 20150401; Y02E 60/321 20130101; F17C
2221/012 20130101; F17C 2227/045 20130101; F17C 2205/0335 20130101;
F17C 2205/0338 20130101 |
International
Class: |
F17C 13/12 20060101
F17C013/12; F17C 13/04 20060101 F17C013/04 |
Claims
1-20. (canceled)
21. A pressure regulator comprising: a housing having a chamber
with an inlet and an outlet, the chamber including therein a
pressure-sensing assembly with a stationary portion fixed relative
to the housing and a movable portion, the stationary and movable
portions being interconnected by a bellows structure with diaphragm
elements adapted to expand and contract in response to pressure
variations in the chamber; a damper assembly adapted to dampen
oscillations and stabilize movement of the pressure-sensing
assembly between open and closed positions, the damper assembly
disposed within a sleeve formed on the movable portion; and a
poppet closure assembly operatively coupled to the pressure-sensing
assembly and adapted to regulate fluid pressure between the inlet
and outlet of the chamber, the poppet closure assembly including a
poppet element and a seating structure located at the inlet of the
chamber, the poppet element having an upper spherical shaped
surface adapted to mate and contact the seating structure to
thereby form a seal with the poppet element.
22. The pressure regulator of claim 21, wherein the seating
structure has a flat cylindrical shape defining the regulator inlet
and wherein contact points between the poppet element and seating
structure are at an obtuse angle so as minimize contact between the
poppet element and the seating structure.
23. The pressure regulator of claim 21, wherein the poppet closure
assembly is comprised of a metal poppet element and a plastic
seating structure.
24. The pressure regulator of claim 21, wherein the poppet closure
assembly is comprised of a metal poppet element and a plastic
seating structure.
25. The pressure regulator of claim 21, wherein the poppet closure
assembly is further comprised of a material of construction having
a low level of deformation while under pressure.
26. The pressure regulator of claim 21, wherein the poppet seating
structure of the poppet closure assembly is comprised of a
non-metallic material.
27. The pressure regulator of claim 21, wherein the poppet closure
assembly further comprises a poppet stem and a retainer spring
assembly that attaches the poppet element to a surface of the
bellows of the pressure regulator, wherein a gap between the
retainer spring and poppet stem has a defined gap dimension,
wherein the poppet stem and retainer spring assembly are configured
for regulating gas flow through the inlet of the regulator.
28. The pressure regulator of claim 21, wherein the outlet of the
chamber further comprises a flow restrictor orifice member selected
from a group consisting of a restricted flow device that reduces
the orifice of the outlet, and a filter member having reduced pore
sizes configured to reduce gas flow.
29. A fluid supply package including the pressure regulator of
claim 21 further comprising: a pressure-regulated fluid storage and
dispensing vessel enclosing the pressure regulator; and a valve
head coupled to the dispensing vessel and adapted for dispensing of
a fluid from the vessel through a discharge port, the pressure
regulator being disposed upstream of the discharge port and coupled
to the valve head, the valve head including a flow control valve
that is operable to control fluid dispensing from the vessel.
30. A pressure regulator comprising: a housing having a chamber
with an inlet and an outlet, the chamber including therein a
pressure-sensing assembly with a stationary portion fixed relative
to the housing and a movable portion, the stationary and movable
portions being interconnected by a bellows structure with diaphragm
elements adapted to expand and contract in response to pressure
variations in the chamber; a damper assembly adapted to dampen
oscillations and stabilize movement of the pressure-sensing
assembly between open and closed positions, the damper assembly
disposed within a sleeve formed on the movable portion; and a
poppet closure assembly operatively coupled to the pressure-sensing
assembly and adapted to regulate fluid pressure between the inlet
and outlet of the chamber, the poppet closure assembly including a
poppet element and a seating structure located at the inlet of the
chamber, the poppet element having a blunt profile shape adapted to
mate and contact the seating structure to form a seal.
31. The pressure regulator of claim 30, wherein the seating
structure has a flat cylindrical shape defining the regulator inlet
and wherein contact points between the poppet element and seating
structure are at an obtuse angle so as minimize contact between the
poppet element and the seating structure.
32. The pressure regulator of claim 30, wherein the poppet closure
assembly is comprised of a metal poppet element and a plastic
seating structure.
33. The pressure regulator of claim 31, wherein the poppet closure
assembly is further comprised of a material of construction having
a low level of deformation while under pressure.
34. The pressure regulator of claim 31, wherein the poppet seating
structure of the poppet closure assembly is comprised of a
non-metallic material.
35. The pressure regulator of claim 30, wherein the poppet closure
assembly further comprises a poppet stem and retainer spring
assembly that attaches the poppet element to a surface of the
bellows of the pressure regulator, wherein a gap between the
retainer spring and poppet stem has a defined gap dimension,
wherein the poppet stem and retainer spring assembly are configured
for regulating gas flow through the inlet of the regulator.
36. The pressure regulator of claim 30, wherein the outlet of the
chamber further comprises a flow restrictor orifice member selected
from a group consisting of a restricted flow device that reduces
the orifice of the outlet, and a filter member having reduced pore
sizes configured to reduce gas flow.
37. A pressure regulator comprising: a housing having a chamber
with an inlet and an outlet, the chamber including therein a
pressure-sensing assembly with a stationary portion fixed relative
to the housing and a movable portion, the stationary and movable
portions being interconnected by a bellows structure with diaphragm
elements adapted to expand and contract in response to pressure
variations in the chamber, the outlet of the chamber including a
restricted flow orifice member configured to reduce a pressure of
an outgoing flow of the pressure regulator; a damper assembly
adapted to dampen oscillations and stabilize movement of the
pressure-sensing assembly between open and closed positions, the
damper assembly disposed within a sleeve formed on the movable
portion; and a poppet closure assembly operatively coupled to the
pressure-sensing assembly and adapted to regulate fluid pressure
between the inlet and outlet of the chamber, the poppet closure
assembly including a poppet element and a seating structure located
at the inlet of the chamber, the poppet element configured to
contact the seating structure to form a seal.
38. The pressure regulator of claim 37, wherein the restricted flow
orifice member includes a filter member configured with a pore size
that restricts high-end gas flow rates.
39. The pressure regulator of claim 37, wherein the restricted flow
orifice member includes a restricted flow device that reduces the
orifice of the outlet of the chamber thereby reducing high-end gas
flow rates.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The benefit of priority of the U.S. Provisional Patent
Application No. 61/704,402 filed in the names of Joseph R. Despres,
et al. for ANTI-SPIKE PRESSURE MANAGEMENT OF PRESSURE-REGULATED
FLUID STORAGE AND DISPENSING VESSELS is hereby claimed under the
provisions of 35 USC 119. The disclosure of U.S. Provisional Patent
Application No. 61/704,402 is hereby incorporated herein by
reference in its entirety, for all purposes.
FIELD
[0002] The present disclosure relates to anti-spike pressure
management of pressure-regulated fluid storage and dispensing
vessels that can be susceptible to pressure-spiking behavior upon
initiation of fluid dispensing operation. The pressure management
arrangements and methods of the present disclosure are also
contemplated for use in resolving continual periodic pressure
spiking (oscillation) behavior, e.g., fluid pressure excursions of
a recurrent episodic character.
DESCRIPTION OF THE RELATED ART
[0003] In the field of semiconductor manufacturing, various fluid
supply packages are used to provide process fluids for use in the
manufacturing operation and in ancillary fluid-utilizing processes
such as process vessel cleaning. As a result of safety and process
efficiency considerations, fluid supply packages have been
developed that utilize fluid storage and dispensing vessels in
which pressure-regulating devices are provided in the interior
volume of the vessel or the vessel valve head. Examples of such
fluid supply packages incorporating pressure-regulated vessels
include the fluid supply packages commercially available from ATMI,
Inc. (Danbury, Conn., USA) under the trademark VAC, the
pressure-regulated vessel fluid supply packages commercially
available from Praxair, Inc. under the trademark UPTIME, and fluid
supply packages equipped with valve heads including regulator and
flow control valve elements commercially available from L'Air
Liquide (Paris, France) under the trademark SANIA.
[0004] In some instances, pressure-regulated vessels coupled to
flow circuitry exhibit sudden pressure fluctuations upon initiation
of fluid dispensing operation. This anomalous behavior is most
frequently experienced as a pressure spike that is sensed by
pressure sensing components in the flow circuitry. Such pressure
spike behavior in previous semiconductor manufacturing operations
has not been consequential, since this is a transient phenomenon
that is quickly replaced by equilibrium flow (and thus the pressure
spike is accommodated in the gradual progression of the process
system to steady-state operating conditions), but recent trends in
rapid beam tuning in ion implant applications have resulted in the
process system being sensitive to this threshold fluctuation.
[0005] The occurrence of the pressure spike can cause flow
circuitry components such as mass flow controllers to temporarily
lose control, with the result that the process tool receiving the
dispensed fluid receives out-of-specification fluid flow. In some
instances, this may result in automatic process monitoring systems
functioning to terminate operation, with consequent downtime
adverse to the maintenance of manufacturing productivity. In other
instances, the manufacturing tool may process the spike-associated
sudden influx of fluid, with the result that out-of-specification
product is produced.
[0006] Accordingly, the consequences of influent fluid pressure
spikes in the fluid flow from pressure-regulated vessels can be
severely detrimental to process efficiency and productivity.
SUMMARY
[0007] The present disclosure relates to anti-spike pressure
management of pressure-regulated fluid storage and dispensing
vessels that are susceptible to pressure-spiking behavior upon
initiation of fluid dispensing operation.
[0008] In one aspect, the disclosure relates to a fluid supply
package comprising a pressure-regulated fluid storage and
dispensing vessel, a valve head adapted for dispensing of fluid
from the vessel, and an anti-pressure spike assembly adapted to
combat pressure spiking in flow of fluid at inception of fluid
dispensing.
[0009] In another aspect, the disclosure relates to a fluid supply
package of the foregoing type, wherein the anti-pressure spike
assembly comprises at least one assembly selected from the group
consisting of:
(1) assemblies adapted to adjust buffer volume between the fluid
storage and dispensing vessel and a mass flow controller disposed
in flow circuitry coupled to the vessel, so as to at least
partially attenuate pressure-spiking behavior of fluid dispensed
from the vessel at inception of fluid dispensing; (2) pressure
regulator assemblies in which internal friction necessary to open
the poppet element of the pressure regulator in the vessel is
effective to at least partially attenuate pressure-spiking behavior
of fluid dispensed from the vessel at inception of fluid
dispensing; (3) assemblies that, immediately prior to initiating
fluid flow, drop delivery line pressure slightly, by maintaining
the delivery line in an evacuated state, and pulse a valve so as to
drop pressure in the line, momentarily flowing a higher fluid flow
rate through a mass flow controller disposed in flow circuitry
coupled to the vessel, to correspondingly lower delivery line fluid
pressure immediately prior to inception of fluid flow; (4)
assemblies that, immediately prior to initiating fluid flow, reduce
delivery line pressure by pulsing directly to vacuum, or by flowing
gas through a mass flow controller in the delivery line at an
increased flow rate (in relation to normal flow rate of dispensed
fluid), or by opening the delivery line directly to vacuum without
pulsing; assemblies that pre-qualify a pressure-regulated vessel,
by a quality assurance determination of pressure profile when the
vessel is connected to a manifold that is at a pressure equal to or
higher than the pressure regulator closure pressure and delivery
line pressure is gradually decreased until the regulator opens,
whereupon the shape of the pressure profile, at the time of
regulator opening provides an indication of whether the
pressure-sensitive element is sticking or not; (5) regulator
assemblies, comprising poppet and pressure regulator sealing
surfaces adapted to prevent poppet sticking when the poppet is
first opened, in which frictional force required to be overcome in
displacing the poppet from its seating structure is effective to at
least partially attenuate pressure-spiking behavior of fluid
dispensed from the vessel at inception of fluid dispensing, wherein
said regulator assemblies include one or more of: (i) materials of
construction having a low level of deformation in use, (ii) poppets
having a spherical sealing shape. (iii) poppet seating structure
comprising a non-metallic material of construction, and (iv)
poppets comprising metal material of construction and poppet
seating structure comprising a fluid-compatible plastic material of
construction; (6) pressure regulators comprising a pressure-sensing
assembly including one or more of: (i) a bellows structure having a
number of diaphragm elements, material of construction, thickness,
and elasticity, so that the travel distance of the poppet element
at least partially attenuates pressure-spiking behavior of fluid
dispensed from the vessel at inception of fluid dispensing; (ii)
orifice size of the pressure regulator device that at least
partially attenuates pressure-spiking behavior of fluid dispensed
from the vessel at inception of fluid dispensing, (iii) regulator
geometry that at least partially attenuates pressure-spiking
behavior of fluid dispensed from the vessel at inception of fluid
dispensing; (7) regulator assemblies comprising one or more of: (i)
multiple springs upstream of the poppet and arranged to assist in
controlling poppet movement, as a damping element when the poppet
element sticks and then suddenly opens; (ii) a pressure adjustment
mechanism for increasing pressure within the pressure sensing
assembly of the pressure regulator device, so that regulator outlet
pressure is correspondingly increased, thereby shortening the
period of time between inception of fluid flow and opening of the
poppet element in the pressure regulator; (iii) a pressure
adjustment mechanism for decreasing inlet pressure to the pressure
regulator, so that the force exerted on the poppet element by fluid
is reduced, thereby reducing the force required to be overcome upon
opening of the poppet; (iv) a flow adjustment mechanism, operative
to closely conform fluid flow to a fluid-utilizing apparatus; (v)
filters positioned downstream of regulator(s), with a pore size
that restricts high-end flow rates, and (vi) restricted flow
orifice elements at an outlet of the regulator(s), e.g., including
provision of a restricted flow orifice (RFO) device(s) and/or
filter(s) between successive ones of series-connected pressure
regulators, so that when a pressure regulator opens, the rate of
gas flowing past the poppet is restrained to attenuate the pressure
spike or to otherwise eliminate pressure oscillation issues; (8)
assemblies comprising at least one restricted flow orifice (RFO)
element at a delivery port of the valve head of the fluid storage
and dispensing vessel to at least partially attenuate
pressure-spiking behavior of fluid dispensed from the vessel at
inception of fluid dispensing; (9) assemblies adapted to adjust
pigtail volume between a delivery port of the fluid storage and
dispensing vessel and a mass flow controller in an associated
delivery line in fluid flow communication with said delivery port,
so that the volume of fluid spiked to higher pressure and duration
of flow perturbation incident to fluid pressure-spiking behavior
are correspondingly reduced; (10) assemblies adapted to limit fluid
flow between successive ones of multiple pressure regulators in an
interior volume of said fluid storage and dispensing vessel,
comprising a flow path reducer in a conduit connecting said
successive ones of said multiple pressure regulators; (11)
assemblies adapted to limit fluid flow between successive ones of
multiple pressure regulators in an interior volume of said fluid
storage and dispensing vessel, comprising a set point adjustment
mechanism, arranged to modulate outlet pressure of a first,
upstream one of said multiple pressure regulators, so that force on
a poppet of a second, downstream regulator, and volume of fluid
between the first and second pressure regulators is adjusted to an
extent effective to at least partially attenuate pressure-spiking
behavior of fluid dispensed from the vessel at inception of fluid
dispensing; (12) pressure regulator assemblies comprising a matably
engageable poppet and seat structure, constructed and arranged so
that contact between the poppet and seat structure when engaged
with one another is made at an obtuse angle therebetween, wherein
the poppet has a round, blunt sealing surface reposable on a flat
cylindrical seat structure; (13) pressure regulator assemblies
comprising a matably engageable poppet and seat structure, wherein
the seat structure comprises a hard, stiff, fluid-compatible
polymer material and the poppet comprises a metal material; (14)
pressure regulator assemblies comprising a poppet stem and retainer
spring assembly that attaches a poppet to a bellows of the pressure
regulator, wherein a gap between the retainer spring and poppet
stem has a gap dimension, that is effective to at least partially
attenuate pressure-spiking behavior of fluid dispensed from the
vessel at inception of fluid dispensing; and (15) pressure
regulator assemblies comprising a flow control element that is
openable and closable in response to pressure at a discharge port
of the fluid supply package, and pressurization/depressurization
assemblies arranged to repetitively and alternatingly apply
pressure and reduce pressure at the discharge port so that the flow
control element of the pressure regulator assembly is cyclically
opened and closed for a predetermined time period to stabilize
pressure and suppress pressure oscillations in subsequent
dispensing operation of the fluid supply package.
[0010] In a further aspect, the disclosure relates to a method for
at least partially attenuating pressure-spiking behavior of fluid
dispensed from a pressure-regulated fluid storage and dispensing
vessel of a fluid supply package, comprising use of one or more
pressure spike-attenuating assemblies of the type(s) described
above.
[0011] Another aspect of the disclosure relates to a fluid supply
package comprising a pressure-regulated vessel including a pressure
regulator therein upstream of a discharge port of the vessel, said
pressure regulator comprising a flow control element that is
openable and closable in response to pressure at the discharge
port, and a pressurization/depressurization assembly arranged to
repetitively and alternatingly apply pressure and reduce pressure
at the discharge port so that the flow control element of the
pressure regulator assembly is cyclically opened and closed for a
predetermined time period to stabilize pressure and suppress
pressure oscillations in subsequent dispensing operation of the
fluid supply package.
[0012] A further aspect of the disclosure relates to a method of
suppressing pressure oscillations in gas dispensed from a
pressure-regulated vessel, said method comprising repetitively and
alternatingly applying pressure and reducing pressure at a
discharge port of the vessel so that a flow control element of a
pressure regulator in the vessel is cyclically opened and closed
for a predetermined time period to stabilize pressure and suppress
pressure oscillations in subsequent dispensing operation of the
fluid supply package.
[0013] Other aspects, features and embodiments of the disclosure
will be more fully apparent from the ensuing description and
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic cross-sectional elevation view of a
fluid supply package including a pressure-regulated fluid storage
and dispensing vessel to which the anti-spike pressure management
apparatus and method may be applied.
[0015] FIG. 2 is a schematic cross-sectional view of a system for
the storage and controlled dispensation of a pressurized fluid
therefrom, according to a further embodiment of the disclosure.
[0016] FIG. 3 is a schematic elevation view, in partial
cross-section, of a fluid supply package of the general type
schematically shown in FIG. 1, and wherein corresponding parts are
correspondingly numbered for ease of reference.
[0017] FIG. 4 is a cross-sectional view of a pressure regulator of
the general type utilized in the vessels shown and described with
respect to the FIGS. 1 and 3.
[0018] FIG. 5 is a schematic representation of a series-arranged
dual regulator assembly, of a type as shown and described with
reference to the fluid supply package of FIGS. 1 and 3.
[0019] FIG. 6 is in large partial view of a pressure regulator of
the general type shown in FIGS. 4 and 5, showing the conical end
section of the poppet seated in the inlet passage of the pressure
regulator, so as to occlude such passage and prevent fluid
flow.
[0020] FIG. 7 is an exploded view of a poppet and stem assembly
utilized in a pressure regulator of the type shown in FIGS.
4-6.
[0021] FIG. 8 is a top plan view of a poppet retainer spring member
which cooperatively mates with the poppet spring assembly of FIG.
7.
[0022] FIG. 9 is a top plan view of the assembled poppet stem and
retainer spring assembly incorporating the poppet stem assembly of
FIG. 7 and the poppet retainer spring member of FIG. 8.
[0023] FIG. 10 is a schematic cross-sectional elevation view of a
fluid supply package of a type as shown in FIG. 1, as modified by
incorporation of a restricted flow orifice (RFO) element in the
fluid discharge passage of the fluid discharge port to suppress
pressure spike behavior on inception of dispensing operation.
[0024] FIG. 11 is a schematic cross-sectional elevation view of a
series-arranged dual regulator assembly, of a type as shown and
previously described with reference to FIG. 5, as modified to
suppress pressure spike behavior, according to another embodiment
of the disclosure.
[0025] FIG. 12 is an enlarged partial view of a pressure regulator
of the general type shown in FIGS. 4 and 5, in which the seat
structure of the inlet passage of the regulator as the poppet have
been modified to at least partially attenuate pressure spike
behavior on inception of dispensing operation.
[0026] FIG. 13 is a schematic cross-sectional elevation view of a
fluid supply package including a pressure-regulated fluid storage
and dispensing vessel to which an anti-spike pressure management
apparatus and method are applied, according to one embodiment of
the present disclosure.
[0027] FIG. 14 is a graph of dispensed gas pressure as a function
of time, before and after cycling of a regulator poppet in a system
of the type shown in FIG. 13.
DETAILED DESCRIPTION
[0028] The present disclosure relates to anti-spike pressure
management of pressure-regulated fluid storage and dispensing
vessels that can be susceptible to pressure-spiking behavior upon
initiation of fluid dispensing operation, and to pressure
management arrangements and methods for combating continual
periodic pressure spiking (oscillation) behavior, such as fluid
pressure excursions of a recurrent episodic character.
[0029] As used herein, the term "pressure-regulated" in reference
to fluid storage and dispensing vessels means that such vessels
have at least one pressure regulator device, set pressure valve, or
vacuum/pressure activated check valve disposed in an interior
volume of the vessel and/or in a valve head of the vessel, with
each such pressure regulator device being adapted so that it is
responsive to fluid pressure in the fluid flow path immediately
downstream of the pressure regulator device, and opens to enable
fluid flow at a specific downstream reduced pressure condition in
relation to the higher fluid pressure upstream of the pressure
regulator device, and subsequent to such opening operates to
maintain the pressure of fluid discharged from the pressure
regulator device at a specific, or "set point," pressure level.
[0030] As previously described in the background section hereof,
pressure-regulated vessels have been found to occasionally (or
sporadically) exhibit sudden pressure fluctuations upon initiation
of fluid dispensing operation when coupled to flow circuitry that
subjects pressure regulator device(s) in the vessel to pressure
conditions intended to open the pressure regulator device(s) to
permit fluid flow therethrough. Such sudden pressure fluctuations
constitute anomalous flow behavior that can severely and adversely
impact fluid delivery and process monitoring operations associated
with the pressure-regulated vessel. In many instances,
pressure-regulated fluid storage and dispensing vessels have
exhibited pressure spikes that exceed the capability of mass flow
controller devices utilized in the fluid delivery line coupled to
the vessel, to maintain steady state flow conditions. The result is
flow fluctuation upon start-up of delivery of fluid or restart of
such fluid delivery operation, before equilibrium flow conditions
can be achieved. Previously, this anomaly if present was unnoticed
or inconsequential, but recent trends in rapid beam tuning for ion
implantation tools, has resulted in sensitivity of the process
system to such fluctuation.
[0031] The present disclosure contemplates various approaches as
"fixes" for such "pressure spike" behavior so that dispensing
operation can be initiated more smoothly and without substantial
pressure/flow rate fluctuation consequences. In such approaches,
the pressure regulators are operated so that outlet pressure and
flow from such devices are modulated to damp and at least partially
attenuate any sudden pressure fluctuation at startup.
[0032] These various approaches in corresponding specific
embodiments include the following operational techniques and
arrangements:
(1) minimizing buffer volume between the fluid storage and
dispensing vessel and mass flow controller disposed in flow
circuitry coupled to the vessel; (2) optimizing design of the
pressure regulator to minimize internal friction necessary to open
the poppet element of the pressure regulator in the vessel; (3)
immediately prior to initiating fluid flow, dropping delivery line
pressure slightly, by maintaining the delivery line in an evacuated
state, and pulsing a valve so as to drop pressure in the line,
momentarily flowing a higher fluid flow rate through a mass flow
controller disposed in flow circuitry coupled to the vessel, to
correspondingly lower delivery line fluid pressure immediately
prior to inception of fluid flow; (4) immediately prior to
initiating fluid flow, reducing delivery line pressure by pulsing
directly to vacuum, or by flowing gas through a mass flow
controller in the delivery line at an increased flow rate (in
relation to normal flow rate of dispensed fluid), or by opening the
delivery line directly to vacuum without pulsing; (5)
pre-qualifying a pressure-regulated vessel, by a quality assurance
determination of pressure profile when the vessel is connected to a
manifold that is at a pressure equal to or higher than the pressure
regulator closure pressure and delivery line pressure is gradually
decreased until the regulator opens, whereupon the shape of the
pressure profile, at the time of regulator opening provides an
indication of whether the pressure-sensitive element is sticking or
not; improvements to the poppet and pressure regulator sealing
surface to prevent sticking of the poppet when it is first opened,
in which the poppet still provides positive closure and stoppage of
fluid flow in the closed position, but wherein frictional force
required to be overcome in displacing the poppet from its seating
structure is minimized, in which such improvements include one or
more of: (i) selection of alternative materials of construction,
having a low level of deformation in use, (ii) modification of the
shape of the poppet from a conventional conical sealing shape to a
spherical sealing shape, (iii) use of a non-metallic material of
construction for the poppet seating structure, and (iv) use of a
metal poppet element and a fluid compatible plastic material of
construction for the poppet seating structure; (6) modifications of
the bellows and pressure-sensing assembly of the pressure regulator
device, to include one or more of: (i) modification of the bellows
structure, such as by variation of the number of diaphragm
elements, material of construction, thickness, and elasticity of
the bellows, so that the travel distance of the poppet element is
reduced; (ii) reduction of orifice size of the pressure regulator
device, (iii) modification of geometry of the regulator; (7)
modification of design of the pressure regulator device, by one or
more of: (i) addition of a spring upstream of the poppet element to
assist in controlling poppet movement, as a damping element when
the poppet element sticks and then suddenly opens; (ii) increasing
pressure within the pressure sensing assembly of the pressure
regulator device, so that regulator outlet pressure is
correspondingly increased, thereby shortening the period of time
between inception of fluid flow and opening of the poppet element
in the pressure regulator; (iii) decreasing inlet pressure to the
pressure regulator, so that the force exerted on the poppet element
by fluid is reduced, thereby reducing the force required to be
overcome upon opening of the poppet element; (iv) a flow adjustment
mechanism, operative to closely conform fluid flow to a
fluid-utilizing apparatus; (v) filters positioned downstream of
regulator(s), with a pore size that restricts high-end flow rates,
and (vi) restricted flow orifice elements at an outlet of the
regulator(s), e.g., including provision of a restricted flow
orifice (RFO) device(s) and/or filter(s) between successive ones of
series-connected pressure regulators, so that when a pressure
regulator opens, the rate of gas flowing past the poppet is
restrained to attenuate the pressure spike or to otherwise
eliminate pressure oscillation issues; (8) deployment of smaller
diameter restricted flow orifice (RFO) elements, at the delivery
port of the fluid storage and dispensing vessel, to restrain
maximum flow rate incident to a pressure spike event; (9)
minimization of "pigtail" volume between the delivery port of the
fluid storage and dispensing vessel and the mass flow controller in
the associated delivery line, so that the volume of fluid spiked to
higher pressure is minimized and duration of flow perturbation
incident to the spike is correspondingly reduced; (10) minimization
of volume between successive regulators in dual regulator
arrangements, e.g., in which a first, upstream regulator effects
fluid pressure reduction from a high storage pressure of the fluid
in the vessel to an intermediate pressure that may for example be
on the order of 100 psi (689.5 kPa), and in which the second,
downstream regulator effects fluid pressure reduction from the
intermediate pressure level on the order of 100 psi (689.5 kPa) to
a lower pressure that may for example be on the order of 650 torr
(86.7 kPa), by installation of a flow path reducer such as a metal
sleeve that is operative to minimize the amount of
intermediate-pressure gas exposed to the poppet element in the
second, downstream regulator; (11) reducing outlet pressure of a
first, upstream regulator in a multiple regulator (2 or more
regulators in series) arrangement, e.g., from 100 psi (689.5 kPa)
to 10 psi (69 kPa), so that force on the second, downstream
regulator poppet element is lessened, and so that volume of gas
between the two pressure regulator devices is reduced; (12)
altering geometry of a matably engageable poppet element and seat
structure of the pressure regulator, so that minimal contact is
made at an obtuse angle between such elements, in order to minimize
potential sticking behavior, e.g., wherein the poppet element has a
round, blunt sealing surface reposing on a flat cylindrical
(donut-shaped or washer-shaped) seating structure; (13)
modification of poppet element and seating structure materials of
construction to minimize sticking behavior upon closing and opening
of the pressure regulator, e.g., use of a hard, stiff, fluid
compatible polymer material for the seating structure and metal for
the face of the poppet element; (14) redesign of the poppet stem
and retainer spring assembly that attaches the poppet element to
the bellows of the pressure regulator, to reduce the "play" in the
positioning of the poppet element that otherwise might permit the
poppet element to be misaligned, such as by reducing the gap
between the retainer clip and shoulder on the poppet stem assembly
in order to minimize displacement; and (15) pressure-cycling a flow
control element of a pressure regulator assembly between open and
closed condition for a sufficient number of cycles to stabilize
pressure and suppress pressure oscillations in subsequent
dispensing operation of the fluid supply package.
[0033] Based on such techniques and arrangements, the fluid supply
package may be configured and adapted in various embodiments to
combat pressure spikes, oscillations and other anomalous flow
behavior, by incorporation in the fluid supply package of
corresponding anti-pressure spike assemblies or pressure management
assemblies comprising at least one assembly selected from the group
consisting of:
(1) assemblies adapted to adjust buffer volume between the fluid
storage and dispensing vessel and a mass flow controller disposed
in flow circuitry coupled to the vessel, so as to at least
partially attenuate pressure-spiking behavior of fluid dispensed
from the vessel at inception of fluid dispensing; (2) pressure
regulator assemblies in which internal friction necessary to open
the poppet element of the pressure regulator in the vessel is
effective to at least partially attenuate pressure-spiking behavior
of fluid dispensed from the vessel at inception of fluid
dispensing; (3) assemblies that, immediately prior to initiating
fluid flow, drop delivery line pressure slightly, by maintaining
the delivery line in an evacuated state, and pulse a valve so as to
drop pressure in the line, momentarily flowing a higher fluid flow
rate through a mass flow controller disposed in flow circuitry
coupled to the vessel, to correspondingly lower delivery line fluid
pressure immediately prior to inception of fluid flow; (4)
assemblies that, immediately prior to initiating fluid flow, reduce
delivery line pressure by pulsing directly to vacuum, or by flowing
gas through a mass flow controller in the delivery line at an
increased flow rate (in relation to normal flow rate of dispensed
fluid), or by opening the delivery line directly to vacuum without
pulsing; assemblies that pre-qualify a pressure-regulated vessel,
by a quality assurance determination of pressure profile when the
vessel is connected to a manifold that is at a pressure equal to or
higher than the pressure regulator closure pressure and delivery
line pressure is gradually decreased until the regulator opens,
whereupon the shape of the pressure profile, at the time of
regulator opening provides an indication of whether the
pressure-sensitive element is sticking or not; (5) regulator
assemblies, comprising poppet and pressure regulator sealing
surfaces adapted to prevent poppet sticking when the poppet is
first opened, in which frictional force required to be overcome in
displacing the poppet from its seating structure is effective to at
least partially attenuate pressure-spiking behavior of fluid
dispensed from the vessel at inception of fluid dispensing, wherein
said regulator assemblies include one or more of: (i) materials of
construction having a low level of deformation in use, (ii) poppets
having a spherical sealing shape. (iii) poppet seating structure
comprising a non-metallic material of construction, and (iv)
poppets comprising metal material of construction and poppet
seating structure comprising a fluid-compatible plastic material of
construction; (6) pressure regulators comprising a pressure-sensing
assembly including one or more of: (i) a bellows structure having a
number of diaphragm elements, material of construction, thickness,
and elasticity, so that the travel distance of the poppet element
at least partially attenuates pressure-spiking behavior of fluid
dispensed from the vessel at inception of fluid dispensing, (ii)
orifice size of the pressure regulator device that at least
partially attenuates pressure-spiking behavior of fluid dispensed
from the vessel at inception of fluid dispensing, (iii) regulator
geometry that at least partially attenuates pressure-spiking
behavior of fluid dispensed from the vessel at inception of fluid
dispensing; (7) regulator assemblies comprising one or more of: (i)
multiple springs upstream of the poppet and arranged to assist in
controlling poppet movement, as a damping element when the poppet
element sticks and then suddenly opens; (ii) a pressure adjustment
mechanism for increasing pressure within the pressure sensing
assembly of the pressure regulator device, so that regulator outlet
pressure is correspondingly increased, thereby shortening the
period of time between inception of fluid flow and opening of the
poppet element in the pressure regulator; (iii) a pressure
adjustment mechanism for decreasing inlet pressure to the pressure
regulator, so that the force exerted on the poppet element by fluid
is reduced, thereby reducing the force required to be overcome upon
opening of the poppet; (iv) a flow adjustment mechanism, operative
to closely conform fluid flow to a fluid-utilizing apparatus; (v)
filters positioned downstream of regulator(s), with a pore size
that restricts high-end flow rates, and (vi) restricted flow
orifice elements at an outlet of the regulator(s), e.g., including
provision of a restricted flow orifice (RFO) device(s) and/or
filter(s) between successive ones of series-connected pressure
regulators, so that when a pressure regulator opens, the rate of
gas flowing past the poppet is restrained to attenuate the pressure
spike or to otherwise eliminate pressure oscillation issues; (8)
assemblies comprising at least one restricted flow orifice (RFO)
element at a delivery port of the valve head of the fluid storage
and dispensing vessel to at least partially attenuate
pressure-spiking behavior of fluid dispensed from the vessel at
inception of fluid dispensing; (9) assemblies adapted to adjust
pigtail volume between a delivery port of the fluid storage and
dispensing vessel and a mass flow controller in an associated
delivery line in fluid flow communication with said delivery port,
so that the volume of fluid spiked to higher pressure and duration
of flow perturbation incident to fluid pressure-spiking behavior
are correspondingly reduced; (10) assemblies adapted to limit fluid
flow between successive ones of multiple pressure regulators in an
interior volume of said fluid storage and dispensing vessel,
comprising a flow path reducer in a conduit connecting said
successive ones of said multiple pressure regulators; (11)
assemblies adapted to limit fluid flow between successive ones of
multiple pressure regulators in an interior volume of said fluid
storage and dispensing vessel, comprising a set point adjustment
mechanism, arranged to modulate outlet pressure of a first,
upstream one of said multiple pressure regulators, so that force on
a poppet of a second, downstream regulator, and volume of fluid
between the first and second pressure regulators is adjusted to an
extent effective to at least partially attenuate pressure-spiking
behavior of fluid dispensed from the vessel at inception of fluid
dispensing; (12) pressure regulator assemblies comprising a matably
engageable poppet and seat structure, constructed and arranged so
that contact between the poppet and seat structure when engaged
with one another is made at an obtuse angle therebetween, wherein
the poppet has a round, blunt sealing surface reposable on a flat
cylindrical seat structure; (13) pressure regulator assemblies
comprising a matably engageable poppet and seat structure, wherein
the seat structure comprises a hard, stiff, fluid-compatible
polymer material and the poppet comprises a metal material; (14)
pressure regulator assemblies comprising a poppet stem and retainer
spring assembly that attaches a poppet to a bellows of the pressure
regulator, wherein a gap between the retainer spring and poppet
stem has a gap dimension, that is effective to at least partially
attenuate pressure-spiking behavior of fluid dispensed from the
vessel at inception of fluid dispensing; and (15) pressure
regulator assemblies comprising a flow control element that is
openable and closable in response to pressure at a discharge port
of the fluid supply package, and pressurization/depressurization
assemblies arranged to repetitively and alternatingly apply
pressure and reduce pressure at the discharge port so that the flow
control element of the pressure regulator assembly is cyclically
opened and closed for a predetermined time period to stabilize
pressure and suppress pressure oscillations in subsequent
dispensing operation of the fluid supply package.
[0034] In the utilization of the above-described assemblies that,
immediately prior to initiating fluid flow, reduce delivery line
pressure by pulsing directly to vacuum, or by flowing gas through a
mass flow controller in the delivery line at an increased flow rate
(in relation to normal flow rate of dispensed fluid), or by opening
the delivery line directly to vacuum without pulsing, there are
various ways in which each of these operations can be carried out,
with respect to flow circuitry and valve sequencing.
[0035] For example, evacuation of a delivery line may be carried
out only back to a shut-off valve located in the delivery line.
Alternatively, evacuation of the delivery line may be carried out
back to the fluid storage and delivery vessel flow control valve.
As a still further alternative, the delivery line flow circuitry
may be evacuated all the way back to the regulator assembly in the
pressure-regulated vessel. Once a particular required vacuum level
is met, or once vacuum has been exerted on the delivery line for a
prescribed time period, the normal flow of dispensed fluid can
proceed. Such procedures, other than the approach of pulling vacuum
all the way back to the pressure regulator in the fluid supply
vessel, can be performed after initiation of dispensing fluid flow.
In this manner, a vacuum will be maintained within some portion of
the delivery line, and when fluid flow is restarted, the vacuum
will have the tendency to force the poppet (or corresponding
displaceable flow modulating element in the pressure regulator) to
open sooner than it otherwise would. Further, this vacuum technique
may eliminate the pressure spike altogether, since once the valves
in the flow path are opened to fluid flow, the resulting delivery
line pressure will be sufficiently low to cause the poppet or other
flow modulating element in the pressure regulator to open
immediately.
[0036] In the foregoing discussion relating to assemblies that are
effective to at least partially attenuate pressure-spiking behavior
of fluid dispensed from the vessel at inception of fluid
dispensing, it is to be understood that the effectiveness being
specified is in relation to a corresponding fluid supply package
lacking the particular assembly that is being considered.
[0037] The present disclosure further contemplates methodologies
for at least partially attenuating pressure-spiking behavior of
fluid dispensed from a pressure-regulated fluid storage and
dispensing vessel of a fluid supply package, comprising use of one
or more pressure spike-attenuating assemblies described
hereinabove.
[0038] The disclosure in one aspect relates to a fluid supply
package comprising a pressure-regulated vessel including a pressure
regulator therein upstream of a discharge port of the vessel, such
pressure regulator comprising a flow control element that is
openable and closable in response to pressure at the discharge
port, and a pressurization/depressurization assembly arranged to
repetitively and alternatingly apply pressure and reduce pressure
at the discharge port so that the flow control element of the
pressure regulator assembly is cyclically opened and closed for a
predetermined time period to stabilize pressure and suppress
pressure oscillations in subsequent dispensing operation of the
fluid supply package.
[0039] The flow control element of the pressure regulator may
comprise a poppet or other valve element or part of the pressure
regulator.
[0040] In the aforementioned fluid supply package, the
pressure-regulated vessel may comprise a series arrangement of
pressure regulators in the interior volume of the vessel, e.g., two
or more regulators in series. The set point of the pressure
regulators may have any suitable value, and in various embodiments
the pressure regulator immediately upstream of the discharge port
may have a subatmospheric pressure set point.
[0041] The disclosure in another aspect relates to a method of
suppressing pressure oscillations in gas dispensed from a
pressure-regulated vessel, such method comprising repetitively and
alternatingly applying pressure and reducing pressure at a
discharge port of the vessel so that a flow control element of a
pressure regulator in the vessel is cyclically opened and closed
for a predetermined time period to stabilize pressure and suppress
pressure oscillations in subsequent dispensing operation of the
fluid supply package. In such method, the pressure-regulated vessel
may comprise a series arrangement of pressure regulators in the
interior volume of the vessel, and the pressure regulator
immediately upstream of the discharge port may have a
subatmospheric pressure set point.
[0042] Referring now to the drawings. FIG. 1 is a schematic
cross-sectional elevation view of an illustrative fluid supply
package 200 including a pressure-regulated fluid storage and
dispensing vessel to which the anti-spike pressure management
apparatus and method of the present disclosure may be applied.
[0043] The fluid supply package 200 includes a fluid storage and
dispensing vessel 212 comprising a cylindrical sidewall 214 and a
floor 216 corporately enclosing the interior volume 218 of the
vessel. The side wall and floor may be formed of any suitable
material of construction, e.g., metal, gas-impermeable plastic,
fiber-resin composite material, etc., as appropriate to the gas to
be contained in the vessel, the end use environment of the
apparatus, and the pressure levels to be maintained in the vessel
in storage and dispensing use.
[0044] At its upper end 220, the vessel features a neck 221
defining a port opening 222 bounded by the inner wall 223 of the
neck 221. The inner wall 223 may be threaded or otherwise
complementarily configured to matably engage therein a valve head
225 including valve body 226 that may be complementarily threaded
or otherwise configured for such engagement.
[0045] In such manner, the valve head 225 is engaged with the
vessel 212 in a leak-tight manner, to hold gas therein in the
interior volume 218 at the desired storage conditions.
[0046] The valve head body 226 is formed with a central vertical
passage 228 therein for dispensing of gas deriving from fluid in
the vessel 212. The central vertical passage 228 communicates with
the fluid discharge passage 230 of fluid discharge port 229, as
shown.
[0047] The valve head body contains a valve element 227 that is
coupled with the valve actuator 238 (hand wheel or pneumatic
actuator), for selective manual or automated opening or closing of
the valve. In this fashion, the valve actuator may be opened to
flow gas through the central vertical passage 228 to the fluid
discharge port 229, or alternatively the valve actuator may be
physically closed, to terminate flow of fluid from the central
vertical passage 228 to the fluid discharge port 229 during the
dispensing operation.
[0048] The valve actuator thus can be any of various suitable
types, e.g., manual actuators, pneumatic actuators,
electromechanical actuators, etc., or any other suitable devices
for opening and closing the valve in the valve head.
[0049] The valve element 227 is therefore arranged downstream of
the regulator, so that fluid dispensed from the vessel flows
through the regulator prior to flow through the flow control valve
comprising valve element 227.
[0050] The valve head body 226 also contains a fill passage 232
formed therein to communicate at its upper end with a fill port
234. The fill port 234 is shown in the FIG. 1 drawing as capped by
fill port cap 236, to protect the fill port from contamination or
damage when the vessel has been filled and placed into use for the
storage and dispensing of fluid from the contained fluid.
[0051] The fill passage at its lower end exits the valve head body
226 at a bottom surface thereof as shown. When the fill port 234 is
coupled with a source of the gas to be contained in the vessel, the
fluid can flow through the fill passage and into the interior
volume 218 of the vessel 212.
[0052] Joined to the lower end of valve head body 226 is an
extension tube 240, containing an upper particle filter 239
therein. Upper regulator 242 is mounted on the end of the extension
tube 240. The upper regulator 242 is secured to the extension tube
lower end in any suitable manner, as for example by providing
internal threading in the lower end portion of the extension tube,
with which the regulator 242 is threadably enagageable.
[0053] Alternatively, the upper regulator may be joined to the
lower end of the extension tube by compression fittings or other
leak-tight vacuum and pressure fittings, or by being bonded
thereto, e.g., by welding, brazing, soldering, melt-bonding, or by
suitable mechanical joining means and/or methods, etc.
[0054] The upper regulator 242 is arranged in series relationship
with a lower regulator 260, as shown. For such purpose, the upper
and lower regulators may be threadably engageable with one another,
by complementary threading comprising threading on the lower
extension portion of the upper regulator 242, and threading that is
matably engageable therewith on the upper extension portion of the
lower regulator 260.
[0055] Alternatively, the upper and lower regulators may be joined
to one another in any suitable manner, as for example by coupling
or fitting means, by adhesive bonding, welding, brazing, soldering,
etc., or the upper and lower regulators may be integrally
constructed as components of a dual regulator assembly.
[0056] At its lower end, the lower regulator 260 is joined to high
efficiency particle filter 246.
[0057] The high efficiency particle filter 246 serves to prevent
contamination of the regulator elements and valve element 227 with
particulates or other contaminating species that otherwise may be
present in the fluid flowed through the regulators and valves in
the operation of the apparatus.
[0058] The embodiment shown in FIG. 1 also has a high efficiency
particle filter 239 disposed in the extension tube 240, to provide
further particulate removal capability, and to ensure high gas
purity of the dispensed fluid.
[0059] Preferably, the regulator has at least one particle filter
in series flow relationship with it. Preferably, as shown in the
FIG. 1 embodiment, the system includes a particle filter upstream
of the regulator(s), as well as a particle filter downstream of the
regulator(s), in the fluid flow path from the vessel interior
volume 218 to the fluid discharge port 229.
[0060] The valve head 225 in the FIG. 1 embodiment thus provides a
two-port valve head assembly--one port is the gas fill port 234,
and another port is the gas discharge port 229.
[0061] The pressure regulators in the FIG. 1 embodiment are each of
a type including a diaphragm element coupled with a
poppet-retaining wafer. The wafer in turn is connected to the stem
of a poppet element, as part of a pressure sensing assembly that
precisely controls outlet fluid pressure. A slight increase in
outlet pressure above set point causes the pressure sensing
assembly to contract, and a slight decrease in the outlet pressure
causes the pressure sensing assembly to expand. The contraction or
expansion serves to translate the poppet element to provide precise
pressure control. The pressure sensing assembly has a set point
that is pre-established or set for the given application of the
fluid storage and dispensing system.
[0062] As illustrated, a gas discharge line 266, containing a flow
control device 268 therein, is coupled with the discharge port 229.
By this arrangement, the flow control device in the gas discharge
line is opened to flow gas from the vessel 212 to the associated
process facility 270 (e.g., a semiconductor manufacturing facility
or other use facility), in the dispensing mode of the fluid storage
and dispensing package 200, when fluid from the storage and
dispensing vessel is flowed through the upstream (lower) regulator
260 and then through the downstream (upper) regulator 242 to the
valve head to the discharge port 229. The flow control device 268
may be of any suitable type, and in various embodiments may
comprise a mass flow controller.
[0063] The fluid dispensed in such manner will be at a pressure
determined by the set point of the regulator 242.
[0064] The respective set points of the regulator 260 and the
regulator 242 in the FIG. 1 embodiment may be selected or preset at
any suitable values to accommodate a specific desired end use
application.
[0065] For example, the lower (upstream) regulator 260 may have a
set point that is in a range of from about 20 psig to about 2500
psig. The upper (downstream) regulator 242 may have a set point
that is above the pressure set point of the lower (upstream)
regulator 260, e.g., in a range of from about 1 torr up to 2500
psig.
[0066] In one illustrative embodiment, the lower (upstream)
regulator 260 has a set point pressure value that is in the range
of from about 100 psig to about 1500 psig, while the upper
(downstream) regulator 242 has a set point pressure value in the
range of from about 100 torr to about 50 psig, wherein the lower
(upstream) pressure set point is above the set point of the upper
(downstream) regulator.
[0067] Although the set points of the regulators in a serial
regulator assembly may be established in any suitable ratio in
relation to one another, in a two-regulator assembly such as shown
in FIG. 1, the upstream regulator in preferred practice
advantageously has a pressure set point that is at least twice the
set point value (measured in the same pressure units of
measurement) of the downstream regulator.
[0068] In the FIG. 1 embodiment, the lower and upper regulators are
coaxially aligned with one another to form a regulator assembly
having particulate filters on either end. As a consequence of such
arrangement, the fluid dispensed from the vessel 212 is of
extremely high purity.
[0069] As a further modification, the particulate filters may be
coated or impregnated with a chemical adsorbent that is selective
for impurity species present in the fluid to be dispensed (e.g.,
decomposition products deriving from reaction or degradation of the
gas in the vessel). In this manner, the fluid flowing through the
particulate filter is purified in situ along the flow path as it is
being dispensed.
[0070] In one illustrative embodiment of a fluid storage and
dispensing system of the type shown in FIG. 1, the vessel 212 is a
3AA 2015 DOT 2.2 liter cylinder. The high efficiency particle
filter 246 is a GasShield.TM. PENTA.TM. point-of-use fluid filter,
commercially available from Mott Corporation (Farmington, Conn.),
having a sintered metal filtration medium in a housing of 316L
VAR/electropolished stainless steel or nickel capable of greater
than 99.9999999% removal of particles down to 0.003 micron
diameter. The high efficiency particle filter 239 is a Mott
standard 6610-1/4 in-line filter, commercially available from Mott
Corporation (Farmington, Conn.). The regulators are HF series
Swagelok.RTM. pressure regulators, with the upper (downstream)
regulator 242 having a set point pressure in the range of from 100
Torr to 100 psig, and the lower (upstream) regulator 260 having a
set point pressure in the range of from 100 psig to 1500 psig, and
with the set point pressure of the lower (upstream) regulator 260
being at least twice the set point pressure of the upper
(downstream) regulator 242. In a specific embodiment, the upper
(downstream) regulator 242 may have an inlet pressure of 100 psig
and outlet pressure of 500 torr, and the lower (upstream) regulator
260 may have an inlet pressure of 1500 psig and outlet pressure of
100 psig.
[0071] FIG. 2 is a schematic cross-sectional view of a system for
the storage and controlled dispensation of a pressurized fluid
therefrom, according to a further embodiment to which the
anti-spike pressure management apparatus and method of the present
disclosure may be applied.
[0072] As illustrated in FIG. 2, a system 10 for the storage and
delivery of pressurized and toxic fluid is depicted. System 10
includes high pressure cylinder or tank 12 containing fluid, e.g.,
boron trifluoride, in gaseous or partially gaseous phase. The
compressed gas cylinder can be a conventional 500 cc cylinder, such
as the one approved by the Department of Transportation 3AA
cylinder, but is not limited thereto. A cylinder valve head 14 is
threadably engaged at the top end of cylinder 12. The cylinder
valve head 14 can be a dual-port 316 stainless steel valve, such as
the one manufactured by Ceodeux, Inc. The dual-port valve cylinder
head 14 has a tamper-resistant fill port 16, through which cylinder
12 is filled with product. Upon filling, the user can draw product
from the cylinder through user port 18, which is a face-seal
VCR.TM. port having an outlet opening ranging from about 0.25 to
about 0.5 inches. The interior of the cylinder contains an internal
flow restrictor 20 having an inlet 22. The flow restrictor 20 can
comprise a capillary flow restrictor, e.g., comprising multiple
capillary flow passages. Until exhausted, fluid flows into inlet
22, through the internal flow restrictor and a vacuum actuated
check valve 26, along a fluid flow path, described in detail below,
to user port 18.
[0073] Vacuum actuated check valve 26 contains a bellows chamber
that automatically controls the discharge of fluid from the
cylinder. The check valve 26 can be disposed in the port body of
the dual-port valve, upstream of the dual-port valve, within the
cylinder or partly in the dual-port valve and partly within the
cylinder along the fluid flow path. As shown in the exemplary
embodiment of FIG. 2, the vacuum actuated check valve is fully
disposed inside cylinder 12, by affixing one portion of the check
valve to the housing which is located along the fluid discharge
path. A handle 28 at the top of dual-port valve allows manual
control of the fluid along the fluid discharge path leading to user
port 18. This type of fluid storage and dispensing system is
described in U.S. Pat. Nos. 5,937,895, 6,007,609, 6,045,115, and
7,905,247, albeit with the first three of such patents referencing
a single port valve cylinder head, however the disclosure of all of
such patents are incorporated herein by reference in their
respective entireties.
[0074] The FIG. 2 fluid supply package can be employed for
sub-atmospheric pressure dopant gas delivery for ion implantation.
Regardless of cylinder temperature, elevation or fill volume, the
system delivers product only when a vacuum level between 500-100
torr is applied to the use port. Product cannot flow from the fluid
supply package without such vacuum.
[0075] Fluid stored in and dispensed from the fluid supply package
of the disclosure may be of any suitable type, and may for example
comprise a fluid having utility in semiconductor manufacturing,
manufacture of flat-panel displays, or manufacture of solar
panels.
[0076] The fluid contained in the fluid storage and dispensing
vessel may for example comprise a hydride fluid for semiconductor
manufacturing operations. Examples of hydride fluids of such type
include arsine, phosphine, stibine, silane, chlorosilane, diborane,
germane, disilane, trisilane, methane, hydrogen selenide, hydrogen
sulfide, and hydrogen. Other fluids useful in semiconductor
manufacturing operations may be employed, including acid fluids
such as hydrogen fluoride, boron trichloride, boron trifluoride,
diboron tetrafluoride, hydrogen chloride, halogenated silanes
(e.g., SiF.sub.4) and disilanes (e.g., Si.sub.2F.sub.6), GeF.sub.4,
PF.sub.3, PF.sub.5, AsF.sub.3, AsF.sub.5, He, N.sub.2, O.sub.2,
F.sub.2, Xe, Ar, Kr, CO, CO.sub.2, CF.sub.4, CHF.sub.3,
CH.sub.2F.sub.2, CH.sub.3F, NF.sub.3, COF.sub.2, as well as
mixtures of two or more of the foregoing, etc., having utility in
semiconductor manufacturing operations as halide etchants, cleaning
agents, source reagents, etc. Other reagents which may be thus
stored and delivered include gaseous organometallic reagents used
as precursors for metalorganic chemical vapor deposition (MOCVD)
and atomic layer deposition (ALD).
[0077] FIG. 3 is a schematic elevation view, in partial
cross-section, of a fluid supply package of the general type
schematically shown in FIG. 1, and wherein corresponding parts are
correspondingly numbered for ease of reference. The FIG. 3 fluid
supply package differs from that shown in FIG. 1, in the provision
in the FIG. 3 package of a collar flange member 280 coupled to the
neck of the vessel 212. The valve head body 226 in the FIG. 3
package is secured to the collar flange member 280.
[0078] FIG. 4 is a cross-sectional view of a pressure regulator of
the general type utilized in the vessels shown and described with
respect to the FIGS. 1 and 3. Such pressure regulator is described
in U.S. Pat. No. 5,303,734, the disclosure of which is hereby
incorporated herein by reference in its entirety. As illustrated,
the pressure regulator includes a main central housing
communicating with inlet and outlet passages. A poppet is reposed
in the inlet passage, and is shown in closed position, as engaged
with the seat of the inlet passage, to close such passage to fluid
flow. The poppet is coupled with a stem that in turn is connected
to the pressure sensing assembly in the interior volume of the
pressure regulator. The pressure sensing assembly includes multiple
diaphragms defining a bellows structure, in which the pressure
sensing assembly is responsive to pressure level in the outlet
passage of the regulator, such that pressure in the outlet passage
that is below a predetermined setpoint pressure will cause movement
of the multiple diaphragms and corresponding translation of the
pressure sensing assembly and poppet stem coupled there with, so
that the poppet is disengaged from its seat, to allow fluid flow
through the inlet passage and central chamber of the regulator to
the outlet passage, for flow of fluid from the discharge opening of
the outlet passage.
[0079] When fluid pressure in the outlet passage is above the set
point pressure of the regulator, the pressure sensing assembly will
responsively translate the poppet stem and associated poppet, so
that the poppet engages the seat of the inlet passage, to close the
passage to fluid flow therethrough.
[0080] FIG. 5 is a schematic representation of a series-arranged
dual regulator assembly, of a type as shown and described with
reference to the fluid supply package of FIGS. 1 and 3.
[0081] In this series-arranged regulator assembly, a first pressure
regulator SPR-1 is in series with a second pressure regulator
SPR-2. The respective regulators are coupled with one another by an
intermediate pressure connection passage. Regulator SPR-1 has a
higher pressure set point in relation to the pressure set point of
regulator SPR-2. Regulator SPR-1 is disposed with its high pressure
inlet (High P Inlet) exposed to high pressure fluid when the
regulator assembly is installed in a fluid storage and dispensing
vessel as shown in FIGS. 1 and 3. Regulator SPR-2 is disposed in
series with regulator SPR-1, and may for example have a set point
pressure that is a subatmospheric pressure, so that the downstream
regulator (SPR-2) will not dispense fluid unless its outlet (Sub-At
Outlet) is below the subatmospheric set point pressure of such
regulator SPR-2.
[0082] Accordingly, when regulator SPR-2 opens in response to
outlet pressure below the set point subatmospheric pressure, there
is a corresponding reduction in pressure in the intermediate
pressure connection passage between the two regulators, and when
such intermediate pressure has been reduced below the set point
pressure of regulator SPR-1, then regulator SPR-1 will open, and
fluid will flow from the high-pressure inlet of regulator SPR-1
through such regulator, through the intermediate pressure
connection passage and through the regulator SPR-2 to the
subatmospheric pressure outlet.
[0083] By such arrangement, a high-pressure fluid is contained in a
safe and effective manner in the fluid storage and dispensing
vessel, and pressure of such fluid in dispensing is reduced by the
upstream pressure regulator to an intermediate pressure, and by the
downstream pressure regulator from such intermediate pressure to
the lower discharge pressure determined by the set point of the
downstream pressure regulator.
[0084] FIG. 6 is an enlarged partial view of a pressure regulator
of the general type shown in FIGS. 4 and 5, showing the conical end
section of the poppet seated in the inlet passage of the pressure
regulator, so as to occlude such passage and prevent fluid flow.
Such occluding position is in response to the downstream pressure
in the outlet passage of the pressure regulator being above the set
point pressure of the regulator. The seating position of the poppet
is a site of potential sticking of the poppet that may give rise to
the aforementioned pressure spike behavior upon inception of fluid
flow from the fluid storage and dispensing vessel of the fluid
supply package.
[0085] FIG. 7 is an exploded view of a poppet stem assembly 300
utilized in a pressure regulator of the type shown in FIGS. 4-6.
The poppet stem assembly includes the poppet 304 that engages, when
threaded in the direction indicated by arrow A, the poppet base
structure including baseplate 308, to which poppet stem 306 is
secured, with helical threads 310 disposed at an upper end of the
poppet stem.
[0086] FIG. 8 is a top plan view of a poppet retainer spring member
312 cooperatively matable with the poppet stem assembly of FIG.
7.
[0087] FIG. 9 is a top plan view of the assembled poppet stem and
retainer spring assembly incorporating the poppet stem assembly 300
of FIG. 7 and the poppet spring retainer member 312 of FIG. 8. The
spring assembly clips into the surface of the bellows in the
pressure regulator, and physically retains the poppet stem 306. The
spring 312 has a spacing gap that may for example be on the order
of 1 mm in perpendicular directions of movement, in order to allow
movement of the poppet for alignment purposes. As a result of such
spacing gap being present, the poppet stem may vary in position,
and alignment may consequently be poor or inconsistent,
contributing to potential pressure spike behavior upon inception of
flow through the regulator during dispensing operation.
[0088] To address such alignment and position issues, the present
disclosure contemplates significant reduction of spacing gap
dimensions between the retaining spring and the poppet stem
assembly, as compared to dimensions, conventionally used in such
pressure regulators. For example, in regulators, conventionally
manufactured with the aforementioned 1 mm spacing gap dimensions, a
reduction of the spacing gap to dimensions on the order of 0.25 mm
is contemplated to correspondingly markedly reduce potential
misalignment, and thereby to ameliorate pressure spike events
associated with such misalignment.
[0089] FIG. 10 is a schematic cross-sectional elevation view of a
fluid supply package of a type as shown in FIG. 1, wherein all
corresponding elements and features are correspondingly numbered
for ease of reference, but wherein the valve head body 226 has been
modified by incorporation of a restricted flow orifice (RFO)
element 288 in the fluid discharge passage of the fluid discharge
port 229 to suppress pressure spike behavior on inception of
dispensing operation. By such arrangement, the restricted flow
orifice will limit the rate of potential spike/surge flow of fluid
from the fluid supply package, and thereby serve to damp and at
least partially attenuate spike/surge behavior. Such RFO element
288 may be threaded into discharge port 229 or otherwise
mechanically inserted, affixed, or attached so as to control the
maximum fluid discharge rate from the fluid supply package 200.
[0090] FIG. 11 is a schematic cross-sectional elevation view of a
series-arranged dual regulator assembly, of a type as shown and
previously described with reference to FIG. 5, as modified to
suppress pressure spike behavior, according to another embodiment
of the disclosure.
[0091] In the FIG. 11 series-arranged regulator assembly, the
intermediate pressure connection passage between the first pressure
regulator SPR-1 and second pressure regulator SPR-2 is fabricated
with an insert therein, of annular shape, to provide a central
narrow bore opening in the intermediate pressure connection
passage, for restricted flow of fluid therethrough.
[0092] The annular insert may be installed during weld assembly of
the series-arranged dual regulator assembly, to reduce fluid volume
between the set point regulators SPR-1 and SPR-2. By restricting
the volumetric fluid load passing through the intermediate pressure
connection passage, there will be correspondingly less fluid
susceptible to surge/spike behavior when the set point regulator
SPR-2 first opens in the dispensing operation. As a result, the
magnitude and temporal extent of any pressure perturbation is
damped and at least partially attenuated, in relation to a
corresponding series-arranged dual regulator assembly lacking such
annular insert in the intermediate pressure connection passage.
[0093] Additionally, or alternatively, a series-arranged dual
regulator assembly, of a type as shown and previously described
with reference to FIG. 5, can be modified by reduction of the
pressure set point on the upstream (higher pressure) regulator, to
reduce fluid volume in the intermediate pressure connection passage
between the regulators. For example, an upstream regulator in a
fluid dispensing package of the type shown in FIG. 1 may typically
have a set point pressure on the order of 100 psi (689.5 kPa), and
such set point pressure of the upstream regulator can be reduced,
e.g., to pressure on the order of 10 psi (68.9 kPa), in order to
attenuate pressure spike behavior on inception of dispensing
operation.
[0094] FIG. 12 is an enlarged partial view of a pressure regulator
400 of the general type shown in FIGS. 4 and 5, in which the seat
structure 412 of the inlet passage 402 of the regulator has been
modified to a donut-form structure of flat annular disk-like
character, in relation to the structure shown in FIG. 6. In
addition, the poppet 404 mounted on poppet stem 410 has been
modified to provide a larger round, blunt profile at its proximal
end 406, for matably sealingly engaging the seat structure. In this
embodiment, the seat structure may be formed of any suitable
material, and may for example comprise a hard, stiff, fluid
compatible polymer, such as a polyacetal material. Likewise, the
poppet may be formed of any suitable material compatible with the
seat structure, and may for example be formed of a metal, such as
stainless steel, titanium, nickel, or other metal or material of
construction that is compatible with the other components of the
poppet assembly and regulator, as well as the fluids to be flowed
through such regulator in use.
[0095] FIG. 13 is a schematic cross-sectional elevation view of a
fluid supply package including a pressure-regulated fluid storage
and dispensing vessel to which an anti-spike pressure management
apparatus and method are applied, according to one embodiment of
the present disclosure. In FIG. 13, corresponding features are
correspondingly numbered with respect to the fluid supply package
shown in FIG. 1.
[0096] As shown in FIG. 13, the fluid supply package 200 includes a
fluid storage and dispensing vessel 212 comprising a cylindrical
sidewall 214 and a floor 216 corporately enclosing the interior
volume 218 of the vessel. At its upper end 220, the vessel features
a neck 221 defining a port opening 222 bounded by the inner wall
223 of the neck 221. The inner wall 223 is configured to matably
engage therein a valve head 225 including valve body 226, as
previously described.
[0097] The valve head 225 is engaged with the vessel 212 in a
leak-tight manner, to hold gas in the interior volume 218 at
desired storage conditions. The valve head body 226 is formed with
a central vertical passage 228 for dispensing of gas deriving from
fluid in the vessel 212. The central vertical passage 228
communicates with the fluid discharge passage 230 of fluid
discharge port 229.
[0098] The valve head body contains a valve element 227 that is
coupled with the valve actuator 238 for selective opening or
closing of the valve. The valve actuator may be opened to flow gas
through the central vertical passage 228 to the fluid discharge
port 229, or alternatively the valve actuator may be closed to
terminate fluid flow from the central vertical passage 228 to the
fluid discharge port 229 during dispensing.
[0099] The valve element 227 is downstream of the regulator, so
that fluid dispensed from the vessel flows through the regulator
prior to flow through the flow control valve comprising valve
element 227.
[0100] The valve head body 226 contains fill passage 232
communicating at its upper end with a fill port 234. The fill port
234 is capped by fill port cap 236, to protect the fill port from
contamination or damage when the vessel after filling is used to
store and dispense gas.
[0101] The fill passage at its lower end exits the valve head body
226 at a bottom surface thereof. When the fill port 234 is coupled
with a gas source, the fluid can flow through the fill passage and
into the interior volume 218 of the vessel 212.
[0102] Joined to the lower end of the valve head body 226 is an
extension tube 240, containing an upper particle filter 239
therein. Upper regulator 242 is mounted on the end of the extension
tube 240. The upper regulator 242 is secured to the extension tube
lower end.
[0103] The upper regulator 242 is arranged in series relationship
with a lower regulator 260, as shown. For such purpose, the upper
and lower regulators may be threadably engageable with one another,
by complementary threading comprising threading on the lower
extension portion of the upper regulator 242, and threading that is
matably engageable therewith on the upper extension portion of the
lower regulator 260.
[0104] Alternatively, the upper and lower regulators may be joined
by coupling or fitting elements, by adhesive bonding, welding,
brazing, soldering, etc., or the upper and lower regulators may be
integrally constructed as components of a dual regulator
assembly.
[0105] At its lower end, the lower regulator 260 is joined to
particle filter 246 that serves to prevent contamination of the
regulator elements and valve element 227 with particulates or other
contaminating species in the operation of the apparatus. A particle
filter 239 is disposed in the extension tube 240, to provide
further particulate removal capability, and ensure high gas purity
of the dispensed fluid.
[0106] The regulator may have at least one particle filter in
series flow relationship with it. Preferably, the system includes a
particle filter upstream of the regulator(s), as well as a particle
filter downstream of the regulator(s), in the fluid flow path from
the vessel interior volume 218 to the fluid discharge port 229.
[0107] The valve head 225 thus provides a two-port valve head
assembly--gas fill port 234, and gas discharge port 229.
[0108] The pressure regulators are each of a type including a
diaphragm element coupled with a poppet-retaining wafer. The wafer
in turn is connected to the stem of a poppet element, as part of a
pressure sensing assembly that precisely controls outlet fluid
pressure. A slight increase in outlet pressure above set point
causes the pressure sensing assembly to contract, and a slight
decrease in the outlet pressure causes the pressure sensing
assembly to expand. The contraction or expansion serves to
translate the poppet element to provide precise pressure control.
The pressure sensing assembly has a set point that is
pre-established or set for the given application of the fluid
storage and dispensing system.
[0109] As illustrated, a gas discharge line 266, containing a mass
flow controller 268 therein, is coupled with the discharge port
229. By this arrangement, the mass flow controller in the gas
discharge line is opened to flow gas from the vessel 212 to the
associated process facility 270 (e.g., a semiconductor
manufacturing facility or other use facility), in the dispensing
mode of the fluid storage and dispensing package 200, when fluid
from the storage and dispensing vessel is flowed through the
upstream (lower) regulator 260 and then through the downstream
(upper) regulator 242 to the valve head to the discharge port
229.
[0110] The fluid dispensed in such manner will be at a pressure
determined by the set point of the regulator 242. The respective
set points of the regulator 260 and the regulator 242 can be
selected or preset at any suitable values. The lower and upper
regulators are coaxially aligned with one another to form a
regulator assembly having particulate filters on either end so that
the fluid dispensed from the vessel 212 is of extremely high
purity.
[0111] In order to enable the vessel to deliver gas at consistent
pressure without exhibiting oscillation of delivery pressure that
negatively impacts the downstream process facility 270 and causes
flow disruptions, the gas supply apparatus of FIG. 13 includes a
cycling valve 272 in the gas discharge line 266 that is selectively
cycleable to establish fluid flow communication between the gas
discharge line 266 and one of branch line 274 and 282. Branch line
274 has a flow isolation valve 276 therein and is coupled with a
pump 278 arranged to exert suction on gas discharge line 266, and
to discharge gas in exhaust line 280. Branch line 282 contains
pressurizing pump 284 therein and is joined to pressurizing gas
source 298, with isolation valve 286 in such line serving to
control flow of pressurized gas to the pressurizing pump 284.
[0112] In order to prevent delivery pressure oscillation at the
inception of gas dispensing from the fluid supply package 200, the
poppet element of regulator 242 in the vessel 214 is cycled by
actuating the cycling valve 272 so that during a first period of
operation, the pressurizing pump 284 is actuated and pressurizing
fluid is flowed from pressurizing gas source 298 through line 282,
valve 272, and back in gas discharge line 266 to the discharge port
229. In this manner, the discharge port 229 is back-pressured to a
predetermined pressure for a predetermined period of time,
following which the cycling valve 272 is cycled to close the gas
discharge line to flow communication with branch line 282, and to
open it to branch line 274 with the suction pump 278 actuated, to
exert suction on the discharge port 229 for a second predetermined
period of time. In this manner, the pressure in the gas discharge
line 266 experienced by the discharge port 229 cycles between
pressure above the set point of the regulator 242 and suction
pressure condition below the set point of the regulator 242, so
that the poppet of the regulator 242 opens and closes.
[0113] Such alternation of pressure conditions to cause the
regulator poppet to successively open and close is continued for a
sufficient number of cycles to cause the subsequent dispensing of
gas from the vessel 214 to occur without pressure oscillations.
[0114] In a specific example, the cycling procedure involves
back-pressuring the discharge port to about 700 torr for 12 seconds
and then pumping on the discharge port for 12 seconds in order to
force the poppet in the regulator open and closed, with such
alternation continuing for 500-1000 cycles, following which the
delivery pressure of the dispensed gas will exhibit a stabilized
and non-oscillatory character.
[0115] FIG. 14 is a graph of dispensed gas pressure as a function
of time, before and after cycling of a regulator poppet in a system
of the type shown in FIG. 13. Before cycling, the delivery pressure
(upper line from 200 to 1175 seconds) after initiation of
dispensing displays significant oscillation. After cycling, the
delivery pressure (upper line after 1175 seconds) is consistent and
non-oscillatory in character.
[0116] It will therefore be appreciated that there are a wide
variety of assemblies, approaches and mechanisms that may be
advantageously employed within the broad practice of the present
disclosure, to at least partially attenuate pressure-spiking
behavior incident to inception of fluid dispensing in
pressure-regulated fluid storage and dispensing vessels of
corresponding fluid supply packages.
[0117] While the disclosure has been set out herein in reference to
specific aspects, features and illustrative embodiments, it will be
appreciated that the utility of the disclosure is not thus limited,
but rather extends to and encompasses numerous other variations,
modifications and alternative embodiments, as will suggest
themselves to those of ordinary skill in the field of the present
disclosure, based on the description herein. Correspondingly, the
invention as hereinafter claimed is intended to be broadly
construed and interpreted, as including all such variations,
modifications and alternative embodiments, within its spirit and
scope.
* * * * *