U.S. patent application number 10/942717 was filed with the patent office on 2006-03-16 for control valve assembly for controlling gas flow in gas combustion systems.
Invention is credited to Aaron Jay Knobloch, David Joseph Najewicz, Richard Joseph Saia, Charles Erklin Seeley, Guanghua Wu.
Application Number | 20060057520 10/942717 |
Document ID | / |
Family ID | 35431272 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060057520 |
Kind Code |
A1 |
Saia; Richard Joseph ; et
al. |
March 16, 2006 |
Control valve assembly for controlling gas flow in gas combustion
systems
Abstract
A control valve assembly includes an inlet for receiving a gas
flow and an outlet for providing the gas flow to a gas burner. The
assembly also includes a positive-shutoff valve for interrupting
the gas flow from the inlet. A micro electromechanical system
(MEMS) valve is coupled in series to the positive-shutoff value
between the inlet and the outlet for regulating the gas flow from
the inlet to the outlet.
Inventors: |
Saia; Richard Joseph;
(Niskayuna, NY) ; Najewicz; David Joseph;
(Prospect, KY) ; Seeley; Charles Erklin;
(Niskayuna, NY) ; Wu; Guanghua; (Dublin, CA)
; Knobloch; Aaron Jay; (Rexford, NY) |
Correspondence
Address: |
Patrick S. Yoder;FLETCHER YODER
P.O. Box 692289
Houston
TX
77269-2289
US
|
Family ID: |
35431272 |
Appl. No.: |
10/942717 |
Filed: |
September 16, 2004 |
Current U.S.
Class: |
431/281 ;
126/39BA; 126/39N |
Current CPC
Class: |
F23C 2900/03001
20130101; F23N 2235/18 20200101; F24C 3/12 20130101; F23N 2241/08
20200101; F23N 2237/02 20200101; F23N 1/005 20130101 |
Class at
Publication: |
431/281 ;
126/039.0BA; 126/039.00N |
International
Class: |
F23Q 9/08 20060101
F23Q009/08; F24C 3/00 20060101 F24C003/00 |
Claims
1. A control valve assembly comprising: an inlet for receiving a
gas flow; an outlet for providing the gas flow to a gas burner; a
positive-shutoff valve for interrupting the gas flow from the
inlet; and a micro electromechanical system (MEMS) valve coupled in
series to the positive-shutoff valve between the inlet and the
outlet for regulating the gas flow from the inlet to the
outlet.
2. The assembly of claim 1, further comprising a control circuit
coupled to the positive-shutoff valve and to the MEMS valve for
controlling the gas flow via the positive-shutoff valve and the
MEMS valve.
3. The assembly of claim 2, further comprising a user interface
coupled to the control circuit for providing a user input to the
control circuit.
4. The assembly of claim 3, wherein the control circuit is adapted
to regulate a heat output of the gas burner based upon the user
input.
5. The assembly of claim 1, further comprising a power supply
adapted to actuate the MEMS valve by controlling one of a voltage,
a current or a pulse width modulation.
6. The assembly of claim 1, wherein the MEMS valve comprises an
orifice adapted to provide a desired gas flow for a burner simmer
setting.
7. The assembly of claim 1, wherein a plurality of MEMS valves is
coupled in parallel to provide a desired gas flow to the gas
burner.
8. The assembly of claim 7, wherein at least one positive-shutoff
valve is coupled in series to each of the MEMS valve.
9. The assembly of claim 1, wherein the positive-shutoff valve is
placed upstream of the MEMS valve.
10. The assembly of claim 1, wherein the positive-shutoff valve is
a solenoid valve.
11. The assembly of claim 1, wherein the MEMS valve is mounted on a
heat sinking substrate.
12. The assembly of claim 11, wherein the heat sinking substrate is
aluminum.
13. The assembly of claim 11, further comprising a sealing device
disposed adjacent to the heat sinking substrate, wherein the
sealing device is adapted to seal the gas flow from the heat
sinking substrate.
14. The assembly of claim 13, wherein the sealing device is a
printed seal printed on the heat sinking substrate.
15. The assembly of claim 13, wherein the sealing device is a
thermally conductive gasket.
16. A gas cooking system comprising: a gas burner; and a control
valve assembly comprising: an inlet for receiving a gas flow; an
outlet for providing the gas flow to the gas burner; a
positive-shutoff valve for interrupting gas flow from the inlet;
and a micro electromechanical system (MEMS) valve coupled in series
to the positive-shutoff valve between the inlet and the outlet for
metering the gas flow from the inlet to the outlet.
17. The system of claim 16, wherein a regulator is disposed
upstream of the control valve assembly, the regulator being adapted
to regulate the gas flow from a supply.
18. The system of claim 16, further comprising a control circuit
coupled to the positive-shutoff valve and to the MEMS valve for
controlling the gas flow via the positive-shutoff valve and the
MEMS valve.
19. The system of claim 16, wherein the MEMS valve comprises an
orifice adapted to provide a desired gas flow for a burner simmer
setting.
20. The system of claim 16, wherein a plurality of MEMS valves is
coupled in parallel to provide a desired gas flow to the gas
burner.
21. The system of claim 20, wherein at least one positive-shutoff
valve is coupled in series to each of the MEMS valve.
22. The system of claim 16, wherein the positive-shutoff valve is a
solenoid valve.
23. The system of claim 16, wherein the MEMS valve is mounted on a
heat sinking substrate.
24. The system of claim 16, further comprising a lock-out valve
disposed upstream of the MEMS valve and the positive-shutoff valve,
wherein the lock-out valve is adapted to interrupt the gas flow
from the supply to the gas burner.
25. A micro electromechanical system (MEMS) valve assembly
comprising: a heat sinking substrate; a plurality of MEMS valves
disposed on the heat sinking substrate; a first gas flow device for
receiving a gas flow; a second gas flow device disposed downstream
of the first gas flow device; and a sealing device adapted to seal
the heat sinking substrate between the first gas flow device and
the second gas flow device.
26. The assembly of claim 25, further comprising a control circuit
coupled to the plurality of MEMS valves for regulating the gas flow
via MEMS valves.
27. The assembly of claim 26, further comprising an edge connector
adapted to couple traces from the plurality of MEMS valves to the
control circuit.
28. The assembly of claim 25, wherein the heat sinking substrate is
aluminum.
29. The assembly of claim 25, wherein the sealing device is an
O-ring seal.
30. The assembly of claim 25, wherein the sealing device is a
thermally conductive gasket.
31. A method of controlling a gas flow in a gas combustion system
with a gas burner comprising: receiving the gas flow via an inlet;
controlling the gas flow from the inlet by opening and closing a
positive-shutoff valve; and regulating the gas flow from the inlet
to the gas burner via a MEMS valve when the positive shutoff valve
is open.
32. The method of claim 31, comprising providing the gas flow to
the gas burner via an outlet.
33. The method of claim 31, further comprising regulating the gas
flow by electronically controlling the operation of the
positive-shutoff valve and the MEMS valve based upon a user defined
input.
34. The method of claim 31, wherein regulating the gas flow
comprises providing a desired gas flow to the gas burner via an
orifice.
35. The method of claim 31, wherein regulating the gas flow
comprises providing a desired gas flow to the gas burner via a
plurality of MEMS valves.
36. The method of claim 31, further comprising dissipating heat
generated from the MEMS valve through a heat sinking substrate.
37. A method of manufacturing a control valve assembly for a gas
combustion system comprising: positioning a positive-shutoff valve
adjacent to an inlet of the gas combustion system for controlling a
gas flow through the assembly; coupling a micro electromechanical
system (MEMS) valve in series with the positive-shutoff valve for
regulating flow through the assembly when the positive-shutoff
valve is open; and providing a sealing device adjacent to the MEMS
valve, for sealing the gas flow through the MEMS valve.
38. The method of claim 37, further comprising coupling a plurality
of MEMS valves in parallel for providing a desired flow to the gas
combustion system.
39. The method of claim 37, further comprising coupling an orifice
with the MEMS valve for providing a fixed gas flow to the gas
cooking system.
40. The method of claim 37, further comprising coupling a control
circuit with the positive-shutoff valve and to the MEMS valve.
41. The method of claim 37, comprising mounting the MEMS valve on a
heat sinking substrate for dissipation of heat generated by the
MEMS valve.
Description
BACKGROUND
[0001] The invention relates generally to gas combustion systems,
and more particularly, to control of gas flow in a gas combustion
system.
[0002] Various gas combustion systems are known and are generally
in use. For example, a gas cooking system receives a flammable gas
flow from a supply and this flow of gas is directed to a gas burner
of the gas cooking system. Downstream combustion components, such
as burners, require large cross-sections in the flow circuit to
accommodate flow rates that enable high heat output.
[0003] In general, the gas cooking system employs a flow control
mechanism, such as a manual mechanical valve, for metering the gas
flow from the supply to the gas burner. Certain other natural gas
combustion systems employ electronic control via solenoid actuated
valves to regulate large flows of gas. Such systems employ either a
single continuously variable solenoid valve, or a series of on/off
solenoid valves to regulate the flow.
[0004] Certain other natural gas combustion systems employ a micro
electromechanical systems (MEMS) valve for electronic flow control.
Such MEMS valves are manufactured by employing batch fabrication
processes such as those employed in the integrated circuit industry
to fabricate mechanical or coupled electromechanical devices. The
use of such MEMS devices is advantageous for improved flow control
at lower manufacturing cost. However, designing such systems is
challenging due to large actuation displacement requirements that
are required for such systems as a large cross section area may be
required in the flow circuit to accommodate high levels of flow.
Further, it is difficult to achieve large actuation displacements
with a small MEMS device.
[0005] In systems where MEMS devices are employed for the gas flow
control, it may be difficult to package and integrate a small size
chip of the MEMS device as a part of a macro scale system. In
addition, heat generated by an electrothermal actuator of the MEMS
device during actuation may cause device failure. Therefore, it is
desirable to transfer the generated heat away from the device.
Further, use of electrothermal actuators for flow control requires
individual calibration of the electrothermal actuators with
supporting electronic feedback control for providing accurate low
gas flows. Incorporation of individual calibration of the
electrothermal actuators is a challenge due to costs and added
complexity involved in such calibration arrangements.
[0006] Accordingly, it would be desirable to develop a system for
flow control of a liquid or gaseous medium with a positive shutoff
seal capability. It would also be advantageous to provide a system
that could achieve an accurate low flow control and a high flow
control up to a maximum designed flow for such medium. It would
also be desirable to provide robust, fluidic and electrical
connections for the flow control mechanism for efficient flow
control of the liquid or gaseous medium in such system.
BRIEF DESCRIPTION
[0007] Briefly, in accordance with one aspect of the present
invention a control valve assembly includes an inlet for receiving
a gas flow and an outlet for providing the gas flow to a gas
burner. The assembly also includes a positive-shutoff valve for
interrupting the gas flow from the inlet. A micro electromechanical
system (MEMS) valve is coupled in series to the positive-shutoff
valve between the inlet and the outlet for regulating the gas flow
from the inlet to the outlet.
[0008] In accordance with another aspect of the present invention a
method of controlling a gas flow in a gas combustion system with a
gas burner includes receiving the gas flow via an inlet and
controlling the gas flow from the inlet by opening and closing a
positive-shutoff valve. The method also includes regulating the gas
flow from the inlet to the gas burner via a MEMS valve when the
positive shutoff valve is open.
DRAWINGS
[0009] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0010] FIG. 1 is a diagrammatical representation of a gas burner
system with a control valve assembly for controlling a gas flow to
a gas burner in accordance with aspects of the present
technique;
[0011] FIG. 2 is a diagrammatical representation of an exemplary
control valve assembly for a gas combustion system in accordance
with aspects of the present technique;
[0012] FIG. 3 is an exploded view of the control valve assembly of
FIG. 2;
[0013] FIG. 4 depicts an exemplary flow path of gas via the control
valve assembly of FIG. 2;
[0014] FIG. 5 is a graphical representation of exemplary input
voltage settings for the control valve assembly of FIG. 2 for a low
flow control of gas in accordance with aspects of the present
technique;
[0015] FIG. 6 is a diagrammatical representation of an exemplary
substrate employed to mount MEMS valve dies in accordance with
aspects of the present technique;
[0016] FIG. 7 is a diagrammatical representation of an exemplary
sealing device for the substrate employed to mount the MEMS valve
dies of FIG. 6 according to one aspect of the invention;
[0017] FIG. 8 is a sectional view of the sealing device of FIG.
7;
[0018] FIG. 9 is a diagrammatical representation of an exemplary
substrate illustrating sealing features and assembly for the
substrate of FIG. 6 according to another aspect of the
invention;
[0019] FIG. 10 is a diagrammatical representation of an exemplary
process for manufacturing of the substrate employed to mount the
MEMS valve dies of FIG. 7 according to one aspect of the invention;
and
[0020] FIG. 11 is a diagrammatical representation of an exemplary
process for manufacturing of the substrate employed to mount the
MEMS valve dies of FIG. 7 according to another aspect of the
invention.
DETAILED DESCRIPTION
[0021] FIG. 1 illustrates a gas burner system 10 with a control
valve assembly, according to an embodiment, for use in a gas
operated cooking appliance, such as, but not limited to, gas stove,
gas hobs, and gas ovens. In the embodiment illustrated in FIG. 1,
the gas burner system 10 includes a series of components disposed
in a housing 12. In a presently contemplated configuration, the gas
burner system 10 receives a gas flow from a supply 14 via an inlet
16 and the gas flow is delivered to a gas burner 18 via an outlet
20 for use in various cooking activities. A valve assembly 22 with
a positive-shutoff valve 24 and a micro electromechanical system
(MEMS) valve 26 is coupled between the inlet 16 and the outlet 20
for regulating the gas flow from the inlet 16 to the outlet 20. It
should be noted that, the MEMS valve 26 is coupled in series to the
positive-shutoff valve 24. In this embodiment, the positive-shutoff
valve 24 is disposed upstream of the MEMS valve 26. Further, the
MEMS valve 26 is mounted on a heat sinking substrate 28 that would
be described in a greater detail below. In one embodiment, the gas
burner system 10 includes a plurality of MEMS valves 26 that is
coupled in parallel to provide a desired gas flow to the gas burner
18.
[0022] In one embodiment, the MEMS valve 26 is an electrothermal
actuated plate valve. The electrothermal actuated plate valve
includes a plurality of slots disposed on a silicon die. In this
embodiment, the gas flow via the slots may be regulated by opening
or closing of the slots via a voltage input. In operation, two
electrothermal beams are adapted to cover the slots for closing of
the slots. In addition, the input voltage may result in thermal
expansion of the electrothermal beams thereby opening the slots for
passing the gas flow. Thus, the illustrated valve facilitates an
accurate control of the gas flow at both low flow and maximum flow
conditions.
[0023] Further, a control circuit 30 is coupled to the
positive-shutoff valve 24 and to the MEMS valve 26 for controlling
the gas flow via the positive-shutoff valve 24 and the MEMS valve
26. A user interface 32 may be coupled to the control circuit 30
for providing a user input to the control circuit 30. Examples of
such user interface 32 include knob control, keypad control,
wireless interface, Internet connection and so forth. The user
input may include parameters for controlling the operation of the
positive-shutoff valve 24 and the MEMS valve 26. Further, a power
supply (not shown) may be coupled to the MEMS valve 26 for
controlling the actuation of the MEMS valve 26 via variable
voltage, variable current or pulse width modulation (PWM). In the
illustrated embodiment, the control circuit 30 is adapted to
regulate a heat output of the gas burner 18 based upon the user
input. The control circuit 30 may include a memory device (not
shown) for storing internal references to control the gas flow to
the gas burner 18 to achieve a desired burner output. The internal
references may include lookup tables, analytical functions and so
forth. The control circuit 30 utilizes the internal references to
control the current, voltage or PWM for operating the MEMS valve 26
to achieve a desired burner heat output.
[0024] In operation, the gas burner system 10 receives a gas flow
from the gas supply 14 for example, a gas supply network, gas
cylinder, gas tank and so forth. A regulator 34 disposed up stream
of the valve assembly 22 regulates the gas flow received from the
gas supply 14 before providing the gas flow to the gas burner 18.
According to one embodiment, a lock-out valve 36 may be disposed
upstream of the positive-shutoff valve 24 and the MEMS valve 26 for
interrupting the gas flow from the supply 14 to the gas burner 18.
In one embodiment, the lock-out valve 36 is a solenoid valve.
[0025] In an open condition of the lock-out valve 36, the gas flow
is directed to the positive-shutoff valve 24 that is adapted to
interrupt the gas flow from the inlet 16. In this embodiment, the
positive-shutoff valve 24 is a solenoid valve. However, other types
of valves performing a similar function may be used. The gas burner
system 10 may include a plurality of positive-shutoff valves 24 for
interrupting the gas flow to a plurality of burners 18 employed in
the gas burner system 10. In this embodiment, the operation of the
positive-shutoff valve 24 is controlled by the control circuit 30
that controls the opening or closing of the positive-shutoff valve
24 as desired by a user of the gas burner system 10. In addition,
when the positive-shutoff valve 24 is in an open position the
control circuit 30 also controls the operation of the MEMS valve 26
to control the gas flow between the inlet 16 and the outlet 20. In
operation, the MEMS valve 26 receives a continuous supply of power
for regulating the gas flow between the inlet 16 and the outlet 20.
The supply of power may result in generation of heat and it may be
desirable to dissipate the generated heat away from the MEMS valve
26. In this embodiment, the heat generated by the supply of power
may be dissipated via the heat sinking substrate 28.
[0026] As described above, the gas burner system 10 may employ a
plurality of MEMS valves 26 coupled in parallel for providing a
desired gas flow to the plurality of gas burners 18. Typically, the
gas burner system 10 may include differently sized burners that may
require different gas flows for their operation. It should be noted
that, a plurality of MEMS valves 26 may be coupled together for
providing a high gas flow to a gas burner 18. For example, two MEMS
valves 26 may be coupled in parallel to form a high flow valve 38
that is adapted to provide a desired gas flow to the burner 18. It
should be noted that, the two MEMS valves 26 coupled to form the
high flow valve 38 may be controlled by a single input signal from
the user interface 32. Further, the MEMS valve 26 may include an
orifice that is adapted to provide a desired gas flow for a burner
simmer setting of the gas burner 18. The size of the orifice may be
decided based upon the desired gas flow for a burner simmer setting
of the gas burner 18. Thus, where the positive-shutoff valve 24 is
in an open position the gas flow for a burner simmer setting is
provided to the gas burner 18 via the orifice. The regulated gas
flow from the MEMS valve 26 may then be provided to a venturi
assembly 40 of the gas burner 18 disposed over the cooktop 42.
[0027] FIG. 2 illustrates an exemplary control valve assembly 44
for the gas burner system 10 of FIG. 1. The control valve assembly
22 includes sealing devices 46 and 48 to seal the heat sinking
substrate 28 with the MEMS valve 26 between the inlet 16 and outlet
20 of the control valve assembly 44. In addition, the control valve
assembly 44 may also include additional components such as, a
middle plate 50 and a support plate 52 for supporting the
positive-shutoff valve 24. The assembly of these components is
explained in a greater detail below with reference to FIG. 3.
[0028] Referring now to FIG. 3, an exploded view 54 of the control
valve assembly 44 of FIG. 2 is illustrated. In a presently
contemplated configuration, the positive-shutoff valves 24 may be
coupled to the inlet 16 via the support plate 52. Further, the
middle plate 50 may be placed between the heat sinking substrate 28
and the inlet 16. A gasket 56 may be disposed between the middle
plate 50 and the inlet 16 to seal the gas flow from the heat
sinking substrate 28. As noted above, sealing devices 46 and 48 are
provided adjacent to the heat sinking substrate 28 to seal the gas
flow from the heat sinking substrate 28. In one embodiment, the
sealing devices 46 and 48 are printed seals. In another embodiment,
the sealing devices 46 and 48 are thermally conductive gaskets.
Other suitable sealing devices may, of course, be employed.
[0029] As mentioned above, the gas flow to the gas burner 18 in the
gas burner system 10 may be controlled by the control valve
assembly 22. FIG. 4 illustrates the flow path 58 of gas in the
control valve assembly 22 of FIG. 2. The gas flow is received from
a supply, as represented by the arrow 60. This flow of gas then is
directed in a direction 62 to the gas burner system 10 via the
inlet 16. The gas flow 64 within the gas burner system 10 is then
regulated by the MEMS valve 26 with the positive-shutoff valve 24
in an open position, and the regulated flow of gas 66 is then fed
to the gas burners 18 of the gas burner system 10.
[0030] As described above with reference to FIG. 1, the MEMS valve
26 may include an orifice that is adapted to provide a desired gas
flow for a burner simmer setting of the gas burner 18. FIG. 5
illustrates a graphical representation 68 of exemplary input
voltage settings for the control valve assembly of FIG. 2 for a low
flow control of gas in accordance with aspects of the present
technique. In this embodiment, the abscissa axis 70 represents the
input voltage for the operation of the control valve assembly 22
and the ordinate axis 72 represents the percentage of total flow of
gas to the gas burner 18. The flow of gas in the gas burner system
10 with and without the orifice is represented by the curves 74 and
76 respectively. As can be seen from the curve 74, the flow of gas
may be controlled accurately in a condition where an orifice is in
an always-open condition to provide a desired gas flow 78 for a
burner simmer setting. Alternatively, an accurate control of the
input voltage settings may be required for low flow control of the
gas when the orifice is not provided as can be seen from the curve
76.
[0031] FIG. 6 illustrates a diagrammatical representation of an
exemplary mounting board 80 for mounting of the MEMS valves 26. The
mounting board 80 includes a substrate 82 that is adapted to
dissipate the heat generated by the MEMS valve 26. In one
embodiment, the substrate 82 is aluminum. Further, a plurality of
MEMS valves 26 may be mounted on the substrate 82 and traces 84
from each of the plurality of MEMS valves 26 are connected to an
edge connector 86. The edge connector 86 may be coupled to the
control circuit 30 (not shown) for controlling the operation of the
plurality of the MEMS valves 26.
[0032] The substrate 82 with the MEMS valves 26 as described above
may be sealed to seal the gas flow from the substrate 82 via a
sealing device. FIG. 7 and FIG. 8 illustrate an exemplary substrate
88 with a sealing device 90. In this embodiment, the sealing device
90 is an O-ring seal printed on the substrate 82. FIG. 8
illustrates a sectional view 92 of the substrate 88 with the O-ring
seal 90. In another embodiment, the sealing device 90 is a
thermally conductive gasket. The substrate 82 may include thermally
conductive gaskets on both front and back sides of the substrate
82. Alternatively, the substrate 82 may have an O-ring seal on one
side and a thermally conductive gasket on the other side. FIG. 9
illustrates another exemplary sealing mechanism 94 for sealing the
gas flow from the substrate 82. In this embodiment, the inlet 16
and the outlet 20 include grooves 96 and 98 milled or otherwise
formed on the inlet 16 and the outlet 20 respectively. The grooves
96 and 98 may be used for positioning of the sealing device 90 on
the inlet 16 and the outlet 20. Further, a printed circuit board
100 with metal interconnect layers may be disposed between the
grooves 96 and 98 and a thermally conductive adhesive 102 or other
joining device may be used to couple the printed circuit board 100
with the substrate 82. It should be noted that, the substrate 82
includes a dielectric polymer and metal interconnect layers
disposed on the substrate 82 that will be described in detail below
with reference to FIG. 10 and FIG. 11.
[0033] FIG. 10 illustrates an exemplary process 104 for
manufacturing the substrate 80 of FIG. 6. The process begins at
step 106 where substrate 108 is selected and a dielectric polymer
110 is disposed on the substrate 108. In this embodiment, the
substrate 108 comprises aluminum. Next, as shown in step 112 a
metallic interconnect 114 is disposed on the dielectric polymer 110
in a pre-determined pattern. In this embodiment, the metallic
interconnect 114 comprises copper. However, other metals performing
a similar function may be used. At step 116, a solder mask 118 is
disposed on the metallic interconnect 114 and the dielectric
polymer 110 in a pre-determined pattern. Next, as represented by
step 120 a layer of gold 122 may be plated on the metallic
interconnect 114. The gold layer 122 is adapted to perform the
function of an edge connector. At step 124, the substrate 108 along
with the dielectric polymer 110 may be diced to create a cavity
126.
[0034] Next, at step 128 a portion 130 of the dielectric polymer
110 may be milled out or otherwise removed. As subsequently
represented by step 132, a MEMS die 134 is placed over the milled
portion 130 of the dielectric polymer 110. Further, an adhesive 136
may be employed to couple the die 134 to the substrate 108.
Finally, at step 138 the die 134 is coupled to the substrate 108
via wire bonds 140. The valve assembly manufactured by the process
described above may be employed for regulating a flow of gas 142 in
the gas burner system 10 of FIG. 1.
[0035] FIG. 11 illustrates another exemplary process 144 for
manufacturing the substrate 80 of FIG. 6. The process begins with
step 146 where a substrate 148 may be diced to form a cavity. In
this embodiment, the substrate 148 comprises aluminum. Next, at
step 150 a printed circuit board (PCB) 152 is mounted on the
substrate 148 via an adhesive material 154. Further, at step 156 a
MEMS die 158 is placed on the substrate 148 via a thermally
conductive adhesive material 160. Finally, at step 162 the MEMS die
158 is coupled to the PCB 152 via wire bonds 164. In addition, a
protective lid 166 may be provided to seal the substrate 148.
[0036] As will be appreciated by those skilled in the art, the
present system provides an efficient flow control of a gaseous
medium with a positive-shutoff capability for a gas range or other
system. The system provides an accurate low flow control and a high
flow control up to a maximum designed flow for such medium in the
gas range system. The various aspects of the method described
hereinabove have utility in gas operated cooking appliances for
example, gas cooktops, gas cookers, gas hobs, and gas ovens, among
other applications. As noted above, the method described here may
be advantageous for such systems for controlling the gas flow via
the control valve assembly. In addition, the method also provides
an efficient mechanism for dissipating heat generated via such
control valve assembly.
[0037] While only certain features of the invention have been
illustrated and described herein, many modifications and changes
will occur to those skilled in the art. It is, therefore, to be
understood that the appended claims are intended to cover all such
modifications and changes as fall within the true spirit of the
invention.
* * * * *