Source: http://www.google.com/patents/US7140719?dq=5,266,072
Timestamp: 2016-10-21 16:08:59
Document Index: 135898307

Matched Legal Cases: ['ART01', 'ART02', 'ART03', 'ART04', 'ART06', 'ART07', 'ART08', 'ART09', 'ART25', 'ART28', 'ART32', 'ART33', 'ART34', 'ART39', 'ART44', 'ART45', 'ART48', 'ART52', 'ART54', 'ART56', 'ART57', 'ART58', 'ART59', 'ART61', 'ART62', 'ART66', 'ART68', 'ART69']

Patent US7140719 - Actuator for a micro-electromechanical valve assembly - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsAn elongate actuator is anchored at one end to the wafer substrate to be in electrical contact with the drive circuitry layers. A closure member is mounted on an opposite end of the elongate actuator. The actuator is configured to receive an electrical signal from the drive circuitry layer to displace...http://www.google.com/patents/US7140719?utm_source=gb-gplus-sharePatent US7140719 - Actuator for a micro-electromechanical valve assemblyAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS7140719 B2Publication typeGrantApplication numberUS 10/884,887Publication dateNov 28, 2006Filing dateJul 6, 2004Priority dateJul 15, 1997Fee statusLapsedAlso published asUS6247792, US6425657, US6783217, US7152960, US7226145, US7357488, US20010043253, US20040085402, US20040257403, US20050036001, US20060227184, US20070070124Publication number10884887, 884887, US 7140719 B2, US 7140719B2, US-B2-7140719, US7140719 B2, US7140719B2InventorsKia SilverbrookOriginal AssigneeSilverbrook Research Pty LtdExport CitationBiBTeX, EndNote, RefManPatent Citations (83), Non-Patent Citations (3), Referenced by (25), Classifications (103), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetActuator for a micro-electromechanical valve assembly
US 7140719 B2Abstract
An elongate actuator is anchored at one end to the wafer substrate to be in electrical contact with the drive circuitry layers. A closure member is mounted on an opposite end of the elongate actuator. The actuator is configured to receive an electrical signal from the drive circuitry layer to displace the closure member between a closed position in which the closure member covers the fluid supply opening and ink is inhibited from flowing through the fluid supply channel and an open position. The elongate actuator is shaped so that, in a rest condition, the actuator encloses an arc. The actuator includes a heating portion that is capable of being heated on receipt of the electrical signal to expand. The heating portion is configured so that, when the portion is heated, the resultant expansion of the portion causes the actuator to straighten at least partially and a subsequent cooling of the portion causes the actuator to return to its rest condition thereby displacing the closure between the closed and open positions.
1. An elongate actuator for moving a closure member in a micro-electromechanical valve assembly for controlling a flow of fluid through a fluid supply channel, the channel being defined by a wafer substrate and drive circuitry layers positioned on the wafer substrate and terminating at a fluid supply opening, the actuator having a first end anchored to the wafer substrate so as to be in electrical contact with al least one of the drive circuitry layers and a second end connected to the closure member so as to move it between a closed position, in which the closure member covers the fluid supply opening and ink is inhibited from flowing through the fluid supply channel, and an open position, in which the fluid supply opening is opened to allow the ink to flow through the fluid supply channel, wherein
at least a portion of the actuator, in a rest condition, has an arcuate shape and is configured to be heated, upon receiving an electrical current from the drive circuitry, such that when the portion is heated it expands and causes the actuator to straighten sufficiently to displace the closure member from closed to an open position; and a subsequent cooling of the portion, after the current is discontinued, causes the actuator to return to its rest condition returning the closure to the closed position.
2. An elongate actuator as claimed in claim 1, the actuator including a body portion that is of a resiliently flexible material having a coefficient of thermal expansion which is such that the material can expand to perform work when heated, the heating portion being positioned in the body portion and defining a heating circuit of a suitable metal.
3. An elongate actuator as claimed in claim 2, in which the heating circuit includes a heater and a return trace, the heater being positioned proximate an inside edge of the body portion and the return trace being positioned outwardly of the heater, so that an inside region of the body portion is heated to a relatively greater extent with the result that the inside region expands to a greater extent than a remainder of the body portion.
4. An elongate actuator as claimed in claim 3, in which a serpentine length of said suitable material defines the heater.
5. An elongate actuator as claimed in claim 3, in which the body portion is of polytetrafluoroethylene and the heating circuit is of copper.
6. An elongate actuator as claimed in claim 1, the actuator defining a coil that partially uncoils when the heating portion expands.
This is a Continuation Application of U.S. application Ser. No. 10/693,947, filed on Oct. 28, 2003, now issued U.S. Pat. No. 6,783,217, which is a Continuation Application of U.S. application Ser. No. 10/302,606, filed on Nov. 23, 2002, now issued U.S. Pat. No. 6,644,767, which is a Continuation Application of U.S. application Ser. No. 09/855,094, filed on May 14, 2001, now issued U.S. Pat. No. 6,485,123, which is a Continuation-in-Part of U.S. application Ser. No. 09/112,815, now issued U.S. Pat. No. 6,247,792, filed on Jul. 10, 1998.
The following Australian provisional patent applications are hereby incorporated by reference. For the purposes of location and identification, US patents/patent applications identified by their US patent/patent application serial numbers are listed alongside the Australian applications from which the US patents/patent applications claim the right of priority.
US PATENT/PATENT
APPLICATION (CLAIMING
AUSTRALIAN PRO-
VISIONAL PATENT
FROM AUSTRALIAN PRO-
VISIONAL APPLICATION)
09/113,060
ART01
6,476,863
ART02
09/113,073
ART03
6,322,181
ART04
09/112,747
ART06
6,227,648
ART07
09/112,750
ART08
09/112,746
ART09
09/112,743
09/112,742
09/112,741
6,196,541
6,195,150
09/112,738
09/113,067
6,431,669
6,362,869
6,472,052
6,356,715
09/112,777
09/113,224
ART25
6,366,693
6,329,990
09/113,072
ART28
6,459,495
6,137,500
09/112,796
09/113,071
ART32
6,398,328
ART33
09/113,090
ART34
6,431,704
09/113,222
ART39
09/112,786
6,415,054
09/112,782
ART44
09/113,056
ART45
09/113,059
6,486,886
6,381,361
ART48
6,317,192
09/113,057
09/113,054
ART52
09/112,752
09/112,759
ART54
6,624,848
ART56
6,357,135
ART57
09/113,107
ART58
6,271,931
ART59
6,353,772
6,106,147
ART61
09/112,790
ART62
6,304,291
09/112,788
6,305,770
6,289,262
ART66
6,315,200
ART68
6,217,165
ART69
09/112,781
DOT01
09/113,052
DOT02
6,350,023
Fluid01
6,318,849
Fluid02
09/113,101
Fluid03
09/113,122
6,224,780
IJM01
6,235,212
IJM02
6,280,643
IJM03
6,284,147
IJM04
6,214,244
IJM05
6,071,750
IJM06
6,267,905
IJM07
6,251,298
IJM08
6,258,285
IJM09
6,225,138
IJM10
6,241,904
IJM11
6,299,786
IJM12
09/113,124
IJM13
6,231,773
IJM14
6,190,931
IJM15
6,248,249
IJM16
09/113,120
IJM17
6,241,906
IJM18
09/113,116
IJM19
6,241,905
IJM20
09/113,117
IJM21
6,231,772
IJM22
6,274,056
IJM23
6,290,861
IJM24
6,248,248
IJM25
6,306,671
IJM26
6,331,258
IJM27
6,110,754
IJM28
6,294,101
IJM29
6,416,679
IJM30
6,264,849
IJM31
6,254,793
IJM32
6,235,211
IJM35
6,491,833
IJM36
6,264,850
IJM37
6,258,284
IJM38
6,312,615
IJM39
6,228,668
IJM40
6,180,427
IJM41
6,171,875
IJM42
6,267,904
IJM43
6,245,247
IJM44
6,315,914
IJM45
6,231,148
IR01
09/113,106
IR02
6,293,658
IR04
09/113,104
IR05
6,238,033
IR06
6,312,070
IR10
6,238,111
IR12
09/113,086
IR13
09/113,094
IR14
6,378,970
IR16
6,196,739
IR17
09/112,774
IR18
6,270,182
IR19
6,152,619
IR20
09/113,092
IR21
6,087,638
MEMS02
6,340,222
MEMS03
09/113,062
MEMS04
6,041,600
MEMS05
6,299,300
MEMS06
6,067,797
MEMS07
6,286,935
MEMS09
6,044,646
MEMS10
09/113,065
MEMS11
09/113,078
MEMS12
6,382,769
MEMS13
FIELD OF THE INVENTION The present invention relates to a micro-electromechanical valve assembly.
Many different types of printing have been invented, a large number of which are presently in use. The known forms of print have a variety of methods for marking the print media with a relevant marking media. Commonly used forms of printing include offset printing, laser printing and copying devices, dot matrix type impact printers, thermal paper printers, film recorders, thermal wax printers, dye sublimation printers and ink jet printers both of the drop on demand and continuous flow type. Each type of printer has its own advantages and problems when considering cost, speed, quality, reliability, simplicity of construction and operation etc.
In recent years, the field of ink jet printing, wherein each individual pixel of ink is derived from one or more ink nozzles has become increasingly popular primarily due to its inexpensive and versatile nature.
Many different techniques on ink jet printing have been invented For a survey of the field, reference is made to an article by J Moore, “Non-Impact Printing: Introduction and Historical Perspective”, Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207–220 (1988).
Ink Jet printers themselves come in many different types. The utilisation of a continuous stream ink in ink jet printing appears to date back to at least 1929 wherein U.S. Pat. No. 1,941,001 by Hansell discloses a simple form of continuous stream electrostatic ink jet printing.
U.S. Pat. No. 3,596,275 by Sweet also discloses a process of a continuous ink jet printing including the step wherein the ink jet stream is modulated by a high frequency electro-static field so as to cause drop separation. This technique is still used by several manufacturers including Elmjet and Scitex (see also U.S. Pat. No. 3,373,437 by Sweet et al)
Piezoelectric ink jet printers are also one form of commonly used ink jet printing device. Piezoelectric systems are disclosed by Kyser et. al. in U.S. Pat. No. 3,946,398 (1970) which discloses a diaphragm mode of operation, by Zolten in U.S. Pat. No. 3,683,212 (1970) which discloses a squeeze mode of operation of a piezoelectric crystal, Stemme in U.S. Pat. No. 3,747,120 (1972) which discloses a bend mode of piezoelectric operation, Howkins in U.S. Pat. No. 4,459,601 which discloses a piezoelectric push mode actuation of the ink jet stream and Fischbeck in U.S. Pat. No. 4,584,590 which discloses a shear mode type of piezoelectric transducer element
Recently, thermal ink jet printing has become an extremely popular form of ink jet printing. The ink jet printing techniques include those disclosed by Endo et al in GB 2007162 (1979) and Vaught et al in U.S. Pat. No. 4,490,728. Both the aforementioned references disclose ink jet printing techniques rely upon the activation of an electrothermal actuator which results in the creation of a bubble in a constricted space, such as a nozzle, which thereby causes the ejection of ink from an aperture connected to the confined space onto a relevant print media. Printing devices using the electrothermal actuator are manufactured by manufacturers such as Canon and Hewlett Packard.
As can be seen from the foregoing, many different types of printing technologies are available. Ideally, a printing technology should have a number of desirable attributes. These include inexpensive construction and operation, high speed operation, safe and continuous long term operation etc. Each technology may have its own advantages and disadvantages in the areas of cost, speed, quality, reliability, power usage, simplicity of construction operation, durability and consumables.
The valve assembly that forms the basis of this invention facilitates the achievement of a number of the desirable attributes listed above.
According to a first aspect of the invention, there is provided an elongate actuator for moving a closure member in a micro-electromechanical valve assembly for controlling a flow of fluid through a fluid supply channel, the channel being defined by a wafer substrate and drive circuitry layers positioned on the wafer substrate and terminating at a fluid supply opening, the actuator having a first end anchored to the wafer substrate so as to be in electrical contact with al least one of the drive circuitry layers and a second end connected to the closure member so as to move it between a closed position, in which the closure member covers the fluid supply opening and ink is inhibited from flowing through the fluid supply channel, and an open position, in which the fluid supply opening is opened to allow the ink to flow through the fluid supply channel, wherein
According to another aspect of the invention, there is provided a micro-electromechanical valve assembly for controlling a flow of fluid through a fluid supply channel defined in a wafer substrate and drive circuitry layers positioned on the wafer substrate and terminating at a fluid supply opening, the valve assembly comprising;
an elongate actuator that is anchored at one end to the wafer substrate to be in electrical contact with the drive circuitry layers; and
a closure member that is mounted on an opposite end of the elongate actuator, the actuator being configured to receive an electrical signal from the drive circuitry layer to displace the closure member between a closed position in which the closure member covers the fluid supply opening and ink is inhibited from flowing through the fluid supply channel and an open position, wherein
the elongate actuator is shaped so that, in a rest condition, the actuator encloses an arc, the actuator including a heating portion that is capable of being heated on receipt of the electrical signal to expand, the heating portion being configured so that, when the portion is heated, the resultant expansion of the portion causes the actuator to straighten at least partially and a subsequent cooling of the portion causes the actuator to return to its rest condition thereby displacing the closure between the closed and open positions.
Each actuator may include a body portion that is of a resiliently flexible material having a coefficient of thermal expansion which is such that the material can expand to perform work when heated, the heating portion being positioned in the body portion and defining a heating circuit of a suitable metal.
The heating circuit may include a heater and a return trace, the heater being positioned proximate an inside edge of the body portion and the return trace being positioned outwardly of the heater, so that an inside region of the body portion is heated to a relatively greater extent with the result that the inside region expands to a greater extent than a remainder of the body portion.
A serpentine length of said suitable material may define the heater.
The body portion may be of polytetrafluoroethylene and the heating circuit may be of copper
Each actuator may define a coil that partially uncoils when the heating portion expands.
In accordance with a third aspect of the present invention, there is provided an ink jet nozzle comprising an ink ejection port for the ejection of ink, an ink supply with an oscillating ink pressure interconnected to the ink ejection port, a shutter mechanism interconnected between the ink supply and the ink ejection port, which blocks the ink ejection port, and an actuator mechanism for moving the shutter mechanism on demand away from the ink ejection port so as to allow for the ejection of ink on demand from the ink ejection port.
In another embodiment of the invention, there is provided a method of operating an ink jet printhead that includes a plurality of nozzle arrangements and an ink reservoir, each nozzle arrangement having:
a nozzle chamber and an ink ejection port in fluid communication with the nozzle chamber, and a closure that is operatively positioned with respect to the ink ejection port, the closure being displaceable between open and closed positions to open and close the ink ejection port, respectively, the ink reservoir in fluid communication with the nozzle chambers, the method comprising the steps of: maintaining each closure in the closed position; subjecting ink in the ink reservoir and thus each nozzle chamber to an oscillating pressure, selectively and independently displacing each closure into the open position so that an ink droplet is ejected from the respective ink ejection port as a result of the oscillating pressure. Further, the actuator preferably comprises a thermal actuator which is activated by the heating of one side of the actuator. Preferably the actuator has a coiled form and is uncoiled upon heating. The actuator includes a serpentine heater element encased in a material having a high coefficient of thermal expansion. The serpentine heater concertinas upon heating. Advantageously, the actuator includes a thick return trace for the serpentine heater element. The material in which the serpentine heater element is encased comprises polytetrafluoroethylene. The actuator is formed within a nozzle chamber which is formed on a silicon wafer and ink is supplied to the ejection port through channels etched through the silicon wafer.
Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIG. 1 is an exploded perspective view illustrating the construction of a single ink jet nozzle in accordance with the preferred embodiment;
FIG. 2 is a perspective view, partly in section, of a single ink jet nozzle constructed in accordance with the preferred embodiment;
FIG. 3 provides a legend of the materials indicated in FIGS. 4 to 16;
FIG. 4 to FIG. 16 illustrate sectional views of the manufacturing steps in one form of construction of an ink jet printhead nozzle; and
FIG. 17 shows a schematic, sectional end view of part of an ink jet nozzle array showing two nozzle arrangements of the array;
FIG. 18 shows the array with ink being ejected from one of the nozzle arrangements;
FIG. 19 shows a schematic side view of re-filling of the nozzle of the first nozzle arrangement and
FIG. 20 shows operation of the array preceding commencement of ink ejection from the second of the illustrated nozzle arrangements.
DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS
In the preferred embodiment, an oscillating ink reservoir pressure is used to eject ink from ejection nozzles. Each nozzle has an associated shutter which normally blocks the nozzle. The shutter is moved away from the nozzle by an actuator whenever an ink drop is to be fired.
Turning initially to FIG. 1, there is illustrated in exploded perspective a single ink jet nozzle 10 as constructed in accordance with the principles of the present invention. The exploded perspective illustrates a single ink jet nozzle 10. Ideally, the nozzles are formed as an array on a silicon wafer 12. The silicon wafer 12 is processed so as to have two level metal CMOS circuitry which includes metal layers and glass layers 13 and which are planarised after construction. The CMOS metal layer has a reduced aperture 14 for the access of ink from the back of silicon wafer 12 via an ink supply channel 15.
A bottom nitride layer 16 is constructed on top of the CMOS layer 13 so as to cover, protect and passivate the CMOS layer 13 from subsequent etching processes. Subsequently, there is provided a copper heater layer 18 which is sandwiched between two polytetrafluoroethylene (PTFE) layers 19,20. The copper layer 18 is connected to lower CMOS layer 13 through vias 25,26. The copper layer 18 and PTFE layers 19,20 are encapsulated within nitride borders e.g. 28 and nitride top layer 29 which includes an ink ejection port 30 in addition to a number of sacrificial etched access holes 32 which are of a smaller dimension than the ejection port 30 and are provided for allowing access of a etchant to lower sacrificial layers thereby allowing the use of the etchant in the construction of layers, 18,19,20 and 28.
Turning now to FIG. 2, there is shown a cutaway perspective view of a fully constructed ink jet nozzle 10. The ink jet nozzle uses an oscillating ink pressure to eject ink from ejection port 30. Each nozzle has an associated shutter 31 which normally blocks it The shutter 31 is moved away from the ejection port 30 by an actuator 35 whenever an ink drop is to be fired.
The ports 30 are in communication with ink chambers which contain the actuators 35. These chambers are connected to ink supply channels 15 which are etched through the silicon wafer. The ink supply channels 15 are substantially wider than the ports 30, to reduce the fluidic resistance to the ink pressure wave. The ink channels 15 are connected to an ink reservoir. An ultrasonic transducer (for example, a piezoelectric transducer) is positioned in the reservoir. The transducer oscillates the ink pressure at approximately 100 KHz. The ink pressure oscillation is sufficient that ink drops would be ejected from the nozzle were it not blocked by the shutter 31.
The shutters are moved by a thermoelastic actuator 35. The actuators are formed as a coiled serpentine copper heater 23 embedded in polytetrafluoroethylene (PTFE) 19/20. PTFE has a very high coefficient of thermal expansion (approximately 770�10−6). The current return trace 22 from the heater 23 is also embedded in the PTFE actuator 35, the current return trace 22 is made wider than the heater trace 23 and is not serpentine. Therefore, it does not heat the PTFE as much as the serpentine heater 23 does. The serpentine heater 23 is positioned along the inside edge of the PTFE coil, and the return trace is positioned on the outside edge. When actuated, the inside edge becomes hotter than the outside edge, and expands more. This results in the actuator 35 uncoiling.
The heater layer 23 is etched in a serpentine manner both to increase its resistance, and to reduce its effective tensile strength along the length of the actuator. This is so that the low thermal expansion of the copper does not prevent the actuator from expanding according to the high thermal expansion characteristics of the PTFE.
By varying the power applied to the actuator 35, the shutter 31 can be positioned between the fully on and fully off positions. This may be used to vary the volume of the ejected drop. Drop volume control may be used either to implement a degree of continuous tone operation, to regulate the drop volume, or both.
When data signals distributed on the printhead indicate that a particular nozzle is turned on, the actuator 35 is energized, which moves the shutter 31 so that it is not blocking the ink chamber. The peak of the ink pressure variation causes the ink to be squirted out of the nozzle 30. As the ink pressure goes negative, ink is drawn back into the nozzle, causing drop break-off. The shutter 31 is kept open until the nozzle is refilled on the next positive pressure cycle. It is then shut to prevent the ink from being withdrawn from the nozzle on the next negative pressure cycle.
Each drop ejection takes two ink pressure cycles. Preferably half of the nozzles 10 should eject drops in one phase, and the other half of the nozzles should eject drops in the other phase. This minimises the pressure variations which occur due to a large number of nozzles being actuated.
Referring to FIGS. 17 to 20, the operation of the printhead is described in greater detail. The printhead comprises an array of nozzle arrangements or nozzles 10, two of which are shown as 10.1 and 10.2 in FIG. 17. Each nozzle arrangement 10 has a chamber 58 in which its associated shutter 31 is arranged.
Each chamber 58 is in communication with an ink reservoir 60 via an ink supply channel 36. An ultrasonic transducer in the form of a piezoelectric transducer 62 is arranged n the ink reservoir 60.
As described above, each ink drop ejection takes two ink pressure cycles. The two ink pressure cycles are referred to as a phase. Half of the nozzles 10 should eject ink drops 64 (FIG. 18) in one phase with the other half of the nozzles ejecting ink drops in the other phase.
Consequently, as shown in FIG. 17 of the drawings, the shutter 31.2 of the nozzle 10.2 is in an open position while the shutter 31.1 of the nozzle 10.1 is in its closed position. It will be appreciated that the nozzle 10.2 represents all the open nozzles of the array of the printhead while the nozzle 10.1 represents all the closed nozzles of the array of the printhead.
In a first pressure cycle, the transducer 62 is displaced in the direction of arrows 66 imparting positive pressure to the ink 57 in the reservoir 60 and, via the channels 36, the chambers 58 of the nozzles 10. Due to the fact that the shutter 31.2 of the nozzle 10.2 is open, ink in the ink ejection port 30.2 bulges outwardly as shown by the meniscus 68. After a predetermined interval, the transducer 62 reverses direction to move in the direction of arrows 70 as shown in FIG. 18 of the drawings. This causes necking, as shown at 72, resulting in separation of the ink drop 64 due to a first negative going pressure cycle imparted to the ink 57.
In the second positive pressure cycle, as shown in FIG. 19 of the drawings, with the transducer moving again in the direction of arrow 66, the positive pressure applied to the ink results in a refilling of the chamber 58.2 of the nozzle 10.2. It is to be noted that the shutter 31.2 is still in an open position with the shutter 31.1 still being in a closed position. In this cycle, no ink is ejected from either nozzle 10.1 or 10.2.
Before the second negative pressure cycle, as shown in FIG. 20 of the drawings, the shutter 31.2 moves to its closed position. Then, as the transducer 62 again moves in the direction of arrows 70 to impart negative pressure to the ink 57, a slight concave meniscus 74 is formed at both ink ejection ports 30.1 and 30.2 However, due to the fact that both shutters 31.1 and 31.2 are closed, withdrawal of ink from the chambers 58.1 and 58.2 of the nozzles 10.1 and 10.2, respectively, is inhibited.
The amplitude of the ultrasonic transducer can be altered in response to the viscosity of the ink (which is typically affected by temperature), and the number of drops which are to be ejected in the current cycle. This amplitude adjustment can be used to maintain consistent drop size in varying environmental conditions.
The drop firing rate can be around 50 KHz. The ink jet head is suitable for fabrication as a monolithic page wide printhead. FIG. 2 shows a single nozzle of a 1600 dpi printhead in “up shooter” configuration.
Returning again to FIG. 1, one method of construction of the ink jet print nozzles 10 will now be described. Starting with the bottom wafer layer 12, the wafer is processed so as to add CMOS layers 13 with an aperture 14 being inserted. The nitride layer 16 is laid down on top of the CMOS layers so as to protect them from subsequent etchings.
A thin sacrificial glass layer is then laid down on top of nitride layers 16 followed by a first PTFE layer 19, the copper layer 18 and a second PTFE layer 20. Then a sacrificial glass layer is formed on top of the PTFE layer and etched to a depth of a few microns to form the nitride border regions 28. Next the top layer 29 is laid down over the sacrificial layer using the mask for forming the various holes including the processing step of forming the rim 40 on nozzle 30. The sacrificial glass is then dissolved away and the channel 15 formed through the wafer by means of utilisation of high density low pressure plasma etching such as that available from Surface Technology Systems.
One form of detailed manufacturing process which can be used to fabricate monolithic ink jet printheads operating in accordance with the principles taught by the present embodiment can proceed using the following steps:
1. Using a double sided polished wafer 12, complete drive transistors, data distribution, and timing circuits using a 0.5 micron, one poly, 2 metal CMOS process 13. The wafer is passivated with 0.1 microns of silicon nitride 16. This step is shown in FIG. 4. For clarity, these diagrams may not be to scale, and may not represent a cross section though any single plane of the nozzle. FIG. 3 is a key to representations of various materials in these manufacturing diagrams, and those of other cross referenced ink jet configurations.
2. Etch nitride and oxide down to silicon using Mask 1. This mask defines the nozzle inlet below the shutter. This step is shown in FIG. 5.
3. Deposit 3 microns of sacrificial material 50 (e.g. aluminum or photosensitive polyimide)
4. Planarize the sacrificial layer to a thickness of 1 micron over nitride. This step is shown in FIG. 6.
5. Etch the sacrificial layer using Mask 2. This mask defines the actuator anchor point 51. This step is shown in FIG. 7.
6. Deposit 1 micron of PTFE 52.
7. Etch the PTFE, nitride, and oxide down to second level metal using Mask 3. This mask defines the heater vias 25, 26. This step is shown in FIG. 8.
8. Deposit the heater 53, which is a 1 micron layer of a conductor with a low Young's modulus, for example aluminum or gold.
9. Pattern the conductor using Mask 4. This step is shown in FIG. 9.
10. Deposit 1 micron of PTFE 54.
11. Etch the PTFE down to the sacrificial layer using Mask 5. This mask defines the actuator and shutter This step is shown in FIG. 10.
12. Wafer probe. All electrical connections are complete at this point, bond pads are accessible, and the chips are not yet separated.
13. Deposit 3 microns of sacrificial material 55. Planarize using CMP
14. Etch the sacrificial material using Mask 6. This mask defines the nozzle chamber wall 28. This step is shown in FIG. 11.
15. Deposit 3 microns of PECVD glass 56.
16. Etch to a depth of (approx.) 1 micron using Mask 7. This mask defines the nozzle rim 40. This step is shown in FIG. 12.
17. Etch down to the sacrificial layer using Mask 6. This mask defines the roof of the nozzle chamber, the nozzle 30, and the sacrificial etch access holes 32. This step is shown in FIG. 13.
18. Back-etch completely through the silicon wafer (with, for example, an ASE Advanced Silicon Etcher from Surface Technology Systems) using Mask 7. This mask defines the ink inlets 15 which are etched through the wafer. The wafer is also diced by this etch. This step is shown in FIG. 14.
19. Etch the sacrificial material. The nozzle chambers are cleared, the actuators freed, and the chips are separated by this etch. This step is shown in FIG. 15.
20. Mount the printheads in their packaging, which may be a molded plastic former incorporating ink channels which supply the appropriate color ink to the ink inlets at the back of the wafer. The package also includes a piezoelectric actuator attached to the rear of the ink channels. The piezoelectric actuator provides the oscillating ink pressure required for the ink jet operation.
21. Connect the printheads to their interconnect systems. For a low profile connection with minimum disruption of airflow, TAB may be used. Wire bonding may also be used if the printer is to be operated with sufficient clearance to the paper.
22. Hydrophobize the front surface of the printheads.
23. Fill the completed printheads with ink 57 and test them. A filled nozzle is shown in FIG. 16.
It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the preferred embodiment without departing from the spirit or scope of the invention as broadly described. The present embodiment is, therefore, to be considered in all respects to be illustrative and not restrictive.
The presently disclosed ink jet printing technology is potentially suited to a wide range of printing systems including: colour and monochrome office printers, short run digital printers, high speed digital printers, offset press supplemental printers, low cost scanning printers, high speed pagewidth printers, notebook computers with inbuilt pagewidth printers, portable colour and monochrome printers, colour and monochrome copiers, colour and monochrome facsimile machines, combined printer, facsimile and copying machines, label printers, large format plotters, photograph copiers, printers for digital photographic ‘minilabs’, video printers, PhotoCD printers, portable printers for PDAs, wallpaper printers, indoor sign printers, billboard printers, fabric printers, camera printers and fault tolerant commercial printer arrays.
All of these features can be met or exceeded by the ink jet systems described below with differing levels of difficulty. Forty-five different ink jet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table under the heading Cross References to Related Applications.
Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a print technology may be listed more than once in a table, where it shares characteristics with more than one entry.
al U.S. Pat. No.
4,490,728
Piezo-
Kyser et al
is marginal (~10
(approx. 3.5
μs)
V/μm)
Ferro-
strength of around 3
V/μm can be
static plates
static pull
required (2.0–2.1 T
stressed to approx. 8
IJ38 ,IJ39, IJ40,
can provide 180
μN force
and 10 μm
limited to around 10
kHz. However, this
High speed (>50
kHz) operation can
field attracts an ‘ink
pusher’ at the drop
above air breakdown
expansion bend
“An Ink-jet Head
Microactuator”,
February 1996,
pp 418–423.
IJ33, , IJ34, IJ35,
Radial con-
1970 Zoltan
U.S. Pat. No. 3,683,212
IJ01–IJ07, IJ10–
IJ22–IJ45
IJ01–IJ07, IJ10–IJ14,
IJ16, IJ20, IJ22–IJ45
following: IJ01–
IJ07, IJ09–IJ12,
IJ22, , IJ23–IJ34,
IJ36–IJ41, IJ44
IJ01, IJ03, 1J05,
IJ39, IJ40,, IJ41,
IJ42, IJ43, IJ44,,
success-ion
A flexible ‘blade’ is
76–83
et al., USP
1978, pp 1185–1195
Hawkins et al., USP
Sekiya et al USP
USP 4,799,068
(‘edge
shooter’)
al USP 4,899,181
(‘roof
al USP 4,490,728
(‘up
IJ24, IJ27–IJ45
(‘down
‘waxy’ feel
USP 4,820,346
may ‘block’
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4007464Jan 23, 1975Feb 8, 1977International Business Machines CorporationInk jet nozzleUS4423401Jul 21, 1982Dec 27, 1983Tektronix, Inc.Thin-film electrothermal deviceUS4458255Mar 12, 1982Jul 3, 1984Hewlett-Packard CompanyApparatus for capping an ink jet print headUS4553393Aug 26, 1983Nov 19, 1985The United States Of America As Represented By The Administrator Of The National Aeronautics And Space AdministrationMemory metal actuatorUS4672398Oct 31, 1985Jun 9, 1987Hitachi Ltd.Ink droplet expelling apparatusUS4737802Dec 20, 1985Apr 12, 1988Swedot System AbFluid jet printing deviceUS4812792May 1, 1987Mar 14, 1989Trw Inc.High-frequency multilayer printed circuit boardUS4855567Jan 15, 1988Aug 8, 1989Rytec CorporationFrost control system for high-speed horizontal folding doorsUS4864824Oct 31, 1988Sep 12, 1989American Telephone And Telegraph Company, At&T Bell LaboratoriesThin film shape memory alloy and method for producingUS5029805Apr 7, 1989Jul 9, 1991Dragerwerk AktiengesellschaftValve arrangement of microstructured componentsUS5058856May 8, 1991Oct 22, 1991Hewlett-Packard CompanyThermally-actuated microminiature valveUS5255016Aug 27, 1990Oct 19, 1993Seiko Epson CorporationInk jet printer recording headUS5258774Feb 14, 1992Nov 2, 1993Dataproducts CorporationCompensation for aerodynamic influences in ink jet apparatuses having ink jet chambers utilizing a plurality of orificesUS5612723Mar 8, 1994Mar 18, 1997Fujitsu LimitedUltrasonic printerUS5666141Jul 8, 1994Sep 9, 1997Sharp Kabushiki KaishaInk jet head and a method of manufacturing thereofUS5719604Jul 31, 1995Feb 17, 1998Sharp Kabushiki KaishaDiaphragm type ink jet head having a high degree of integration and a high ink discharge efficiencyUS5812159Jul 22, 1996Sep 22, 1998Eastman Kodak CompanyInk printing apparatus with improved heaterUS5828394Sep 20, 1995Oct 27, 1998The Board Of Trustees Of The Leland Stanford Junior UniversityFluid drop ejector and methodUS6003977Jul 30, 1996Dec 21, 1999Hewlett-Packard CompanyBubble valving for ink-jet printheadsUS6062681Jul 14, 1998May 16, 2000Hewlett-Packard CompanyBubble valve and bubble valve-based pressure regulatorUS6174050Jul 23, 1999Jan 16, 2001Canon Kabushiki KaishaLiquid ejection head with a heat generating surface that is substantially flush and/or smoothly continuous with a surface upstream theretoUS6485123May 14, 2001Nov 26, 2002Silverbrook Research Pty LtdShutter ink jetUS6783217 *Oct 28, 2003Aug 31, 2004Silverbrook Research Pty LtdMicro-electromechanical valve assemblyDE1648322A1Jul 20, 1967Mar 25, 1971Vdo SchindlingMess- oder Schaltglied aus BimetallDE2905063A1Feb 10, 1979Aug 14, 1980Olympia Werke AgInk nozzle air intake avoidance system - has vibratory pressure generator shutting bore in membrane in rest positionDE3245283A1Dec 7, 1982Jun 7, 1984Siemens AgArrangement for expelling liquid dropletsDE3430155A1Aug 16, 1984Feb 27, 1986Siemens AgIndirectly heated bimetalDE3716996A1May 21, 1987Dec 8, 1988Vdo SchindlingDeformation elementDE3934280A1Oct 13, 1989Apr 26, 1990Cae Cipelletti AlbertoRadial sliding vane pump - with specified lining for rotor and rotor drive shaftDE4328433A1Aug 24, 1993Mar 2, 1995Heidelberger Druckmasch AgInk jet spray method, and ink jet spray deviceDE19516997A1May 9, 1995Nov 16, 1995Sharp KkInk jet print head with self-deforming body for max efficiencyDE19517969A1May 16, 1995Nov 30, 1995Sharp KkInk jet printer headDE19525152A1Jul 11, 1995Jun 13, 1996Sotralentz SaStackable pallet holder for transport and storageDE19532913A1Sep 6, 1995Mar 28, 1996Sharp KkHighly integrated diaphragm ink jet printhead with strong deliveryDE19623620A1Jun 13, 1996Dec 19, 1996Sharp KkInk jet printing headDE19639717A1Sep 26, 1996Apr 17, 1997Sharp KkInk=jet print head with piezo-electric actuatorEP0092229A2Apr 19, 1983Oct 26, 1983Siemens AktiengesellschaftLiquid droplets recording deviceEP0398031A1Apr 18, 1990Nov 22, 1990Seiko Epson CorporationInk jet headEP0427291A1Nov 9, 1990May 15, 1991Seiko Epson CorporationInk jet print headEP0431338A2Nov 8, 1990Jun 12, 1991Matsushita Electric Industrial Co., Ltd.Ink recording apparatusEP0478956A2Aug 29, 1991Apr 8, 1992Forschungszentrum Karlsruhe GmbHMicromechanical elementEP0506232A1Feb 25, 1992Sep 30, 1992Videojet Systems International, Inc.Valve assembly for ink jet printerEP0510648A2Apr 23, 1992Oct 28, 1992FLUID PROPULSION TECHNOLOGIES, Inc.High frequency printing mechanismEP0627314A2May 24, 1994Dec 7, 1994OLIVETTI-CANON INDUSTRIALE S.p.A.Improved ink jet print head for a dot printerEP0634273A2Jul 11, 1994Jan 18, 1995Sharp Kabushiki KaishaInk jet head and a method of manufacturing thereofEP0713774A2May 31, 1995May 29, 1996Sharp Kabushiki KaishaInk jet head for high speed printing and method for it's fabricationEP0737580A2Apr 15, 1996Oct 16, 1996Canon Kabushiki KaishaLiquid ejecting head, liquid ejecting device and liquid ejecting methodEP0750993A2Jun 27, 1996Jan 2, 1997Canon Kabushiki KaishaMicromachine, liquid jet recording head using such micromachine, and liquid jet recording apparatus having such liquid jet recording head mounted thereonEP0882590A2Jun 5, 1998Dec 9, 1998Canon Kabushiki KaishaA liquid discharging method, a liquid discharge head, and a liquid discharge apparatusFR2231076A2 Title not availableGB792145A Title not availableGB1428239A Title not availableGB2262152A Title not availableJP3653348A Title not availableJPH0250841A Title not availableJPH0292643A Title not availableJPH0528765A Title not availableJPH0691865A Title not availableJPH0691866A Title not availableJPH01105746A Title not availableJPH01128839A Title not availableJPH01155639A Title not availableJPH01257058A Title not availableJPH01306254A Title not availableJPH02108544A Title not availableJPH02158348A Title not availableJPH02162049A Title not availableJPH02265752A Title not availableJPH03112662A Title not availableJPH03180350A Title not availableJPH04118241A Title not availableJPH04126255A Title not availableJPH04141429A Title not availableJPH04353458A Title not availableJPH04368851A Title not availableJPH05318724A Title not availableJPH07314665A Title not availableJPS6125849A Title not availableJPS58112747A Title not availableJPS58116165A Title not availableJPS61268453A Title not availableWO1994018010A1Jan 27, 1994Aug 18, 1994Domino Printing Sciences PlcInk jet printerWO1997012689A1Sep 11, 1996Apr 10, 1997The Board Of Trustees Of The Leland Stanford Junior UniversityFluid drop ejector and method* Cited by examinerNon-Patent CitationsReference1Ataka, Manabu et al, "Fabrication and Operation of Polymide Bimorph Actuators for Ciliary Motion System". Journal of Microelectromechanical Systems, US, IEEE Inc. New York, vol. 2, No. 4, Dec. 1, 1993, pp. 146-150. XP000443412, ISSN: 1057-7157.2Noworolski, J. Mark et al, "Process for in-plane and out-of-plane single-crystal-silicon thermal microactuators". Sensors and Actuators, A, CH, Elsevier Sequoia S.A., Lausanne, vol. 55, No. 1, Jul. 15, 1996, pp. 65-69, XP004077979 ISSN: 0924-4247.3Yamagata, Yutaka et al, "A Micro Mobile Mechanism Using Thermal Expansion and its Theoretical Analysis". Proceedeing of the workshop on micro electro mechanical systems (MEMS), US, New York, IEEE, vol. Workshop 7, Jan. 25, 1994, pp. 142-147, XP000528408, ISBN: 0 7803 1834 X.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7566113 *Jul 16, 2007Jul 28, 2009Silverbrook Research Pty LtdInkjet nozzle incorporating serpentine actuatorUS7914119Mar 29, 2011Silverbrook Research Pty LtdPrinthead with columns extending across chamber inletUS7934806Jun 29, 2009May 3, 2011Silverbrook Research Pty LtdInkjet nozzle incorporating piston actuatorUS8117751 *Jul 12, 2009Feb 21, 2012Silverbrook Research Pty LtdMethod of forming printhead by removing sacrificial material through nozzle aperturesUS8366243 *Jul 12, 2009Feb 5, 2013Zamtec LtdPrinthead integrated circuit with actuators proximate exterior surfaceUS8393714Nov 14, 2011Mar 12, 2013Zamtec LtdPrinthead with fluid flow controlUS20080012903 *Jul 16, 2007Jan 17, 2008Silverbrook Research Pty LtdInkjet Nozzle Incorporating Serpentine ActuatorUS20090262163 *Jun 29, 2009Oct 22, 2009Silverbrook Research Pty LtdInkjet nozzle incorporating piston actuatorUS20090273622 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Low Operating PowerUS20090273623 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead With Low Power ActuatorsUS20090273632 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Large Nozzle ArrayUS20090273633 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With High Density Nozzle ArrayUS20090273634 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Thin Nozzle LayerUS20090273635 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit For Low Volume Droplet EjectionUS20090273636 *Nov 5, 2009Silverbrook Research Pty LtdElectro-Thermal Inkjet Printer With High Speed Media FeedUS20090273638 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With More Than Two Metal Layer CMOSUS20090273639 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Actuators Proximate Exterior SurfaceUS20090273640 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Small Nozzle AperturesUS20090273641 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead IC With Ink Supply Channel For Multiple Nozzle RowsUS20090273642 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead IC With Low Velocity Droplet EjectionUS20090273643 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdPrinthead Integrated Circuit With Ink Supply Through Wafer ThicknessUS20090273650 *Nov 5, 2009Silverbrook Research Pty LtdPrinthead With Columns Extending Across Chamber InletUS20090275151 *Jul 12, 2009Nov 5, 2009Silverbrook Research Pty LtdMethod Of Forming Printhead By Removing Sacrificial Material Through Nozzle AperturesUS20090278891 *Jul 12, 2009Nov 12, 2009Silverbrook Research Pty LtdPrinthead IC With Filter Structure At Inlet To Ink ChambersUS20090278892 *Nov 12, 2009Silverbrook Research Pty LtdPrinthead IC With Small Ink Chambers* Cited by examinerClassifications U.S. Classification347/54, 348/E05.024, 348/E05.055, 348/E05.142, 347/65International ClassificationG06K19/073, H04N5/225, B41J3/42, G06K1/12, B41J2/175, G06F21/00, G06F1/16, G06K19/06, B41J2/165, G07F7/12, B41J11/00, H04N5/262, B42D15/10, B41J2/045, G07F7/08, B41J2/04, B41J2/14, H04N1/21, B41J2/16, B41J2/05, H04N1/32, B41J15/04, G11C11/56, H04N1/00, B41J11/70, G06K7/14, B41J3/44, H04N5/74Cooperative ClassificationH04N2101/00, H04N5/225, G06K19/06037, B41J2/17596, B41J2/17503, B82Y30/00, B41J2/1637, B41J2/1645, B41J2/1643, B41J2/1629, B41J2202/21, H04N1/2154, G06F21/86, B41J2/1623, B41J2/1626, B41J2/1648, G06F21/79, G11C11/56, B41J2/1646, B41J2/1628, H04N1/2112, B41J2002/041, G06K7/14, G06K7/1417, B41J2/1631, G06K1/121, B41J2/16585, B41J2/1632, G06F2221/2129, B41J2/14427, H04N5/2628, B41J2/1642, B41J2/1635, H04N5/7458, B41J2/1639, B41J2/17513European ClassificationG06F21/86, G06F21/79, B41J2/14S, B41J2/16S, B41J2/16M5, G06K7/14, G06K1/12B, G06K19/06C3, B41J2/16M8T, B41J2/16M3W, B41J2/16M1, B41J2/16M8P, B41J2/16M8S, B41J2/16M3, B41J2/16M7, G11C11/56, H04N1/21B3, B82Y30/00, G06K7/14A2C, H04N1/21B3H, B41J2/175C, B41J2/175C2, B41J2/16M8C, B41J2/175P, B41J15/04, B41J11/00A, B41J2/16M3D, B41J2/16M6, H04N5/262T, B41J2/16M4, B41J2/16M7S, B41J11/70, B41J3/44B, H04N5/225Legal EventsDateCodeEventDescriptionJul 6, 2004ASAssignmentOwner name: SILVERBROOK RESEARCH PTY. LTD., AUSTRALIAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SILVERBROOK, KIA;REEL/FRAME:015581/0534Effective date: 20040608May 18, 2010FPAYFee paymentYear of fee payment: 4Jul 13, 2012ASAssignmentOwner name: ZAMTEC LIMITED, IRELANDFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SILVERBROOK RESEARCH PTY. LIMITED AND CLAMATE PTY LIMITED;REEL/FRAME:028549/0003Effective date: 20120503Jul 11, 2014REMIMaintenance fee reminder mailedNov 28, 2014LAPSLapse for failure to pay maintenance feesJan 20, 2015FPExpired due to failure to pay maintenance feeEffective date: 20141128RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services