Information
-
Patent Grant
-
6464343
-
Patent Number
6,464,343
-
Date Filed
Wednesday, October 31, 200122 years ago
-
Date Issued
Tuesday, October 15, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Barlow; John
- Stephens; Juanita
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
A fluid drop ejecting apparatus including a thin film stack including a plurality of heater resistors formed on a substrate having a feed edge, a patterned fluid barrier layer disposed on the thin film stack, respective fluid chambers formed in the barrier layer over respective heater resistors, fluid feed features formed in the barrier layer between the fluid feed edge and the ink chambers, and a thin film metal structure in a metal layer of the thin film stack and located between the ink feed edge and the fluid chambers.
Description
BACKGROUND OF THE DISCLOSURE
The disclosed invention relates generally to fluid ejecting devices such as ink jet printing devices, and more particularly to a fluid ejecting device having an integrated circuit thin film feature disposed beneath fluid barrier elements.
The art of inkjet printing is relatively well developed. Commercial products such as computer printers, graphics plotters, and facsimile machines have been implemented with ink jet technology for producing printed media. The contributions of Hewlett-Packard Company to ink jet technology are described, for example, in various articles in the Hewlett-Packard Journal, Vol. 36, No. 5 (May 1985); Vol. 39, No. 5 (Oct. 1988); Vol. 43, No. 4 (Aug. 1992); Vol. 43, No. 6 (Dec. 1992); and Vol. 45, No. 1 (Feb. 1994); all incorporated herein by reference.
Generally, an ink jet image is formed pursuant to precise placement on a print medium of ink drops emitted by an ink drop generating device known as an ink jet printhead. Typically, an ink jet printhead is attached to a print cartridge body that is, for example, supported on a movable print carriage that traverses over the surface of the print medium. The ink jet printhead is controlled to eject drops of ink at appropriate times pursuant to command of a microcomputer or other controller, wherein the timing of the application of the ink drops is intended to correspond to a pattern of pixels of the image being printed.
A typical Hewlett-Packard ink jet printhead includes an array of precisely formed nozzles in an orifice structure that is attached to or integral with an ink barrier structure that in turn is attached to a thin film substructure that implements ink firing heater resistors and apparatus for enabling the resistors. The ink barrier structure can define ink flow control structures, particle filtering structures, ink passageways or channels, and ink chambers. The ink chambers are disposed over associated ink firing resistors, and the nozzles in the orifice structure are aligned with associated ink chambers. Ink drop generator regions are formed by the ink chambers and portions of the thin film substructure and the orifice structure that are adjacent the ink chambers.
A consideration with a printhead that employs an ink barrier structure is the reliability and robustness of the adhesion of the barrier layer to the thin film substructure.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the disclosed invention will readily be appreciated by persons skilled in the art from the following detailed description when read in conjunction with the drawing wherein:
FIG. 1
is schematic perspective view of a print cartridge that can incorporate an ink jet printhead in accordance with the invention.
FIG. 2
is a schematic perspective view of an example of a printhead in accordance with the invention.
FIG. 3
is a schematic cross-sectional view of a portion of the printhead of
FIG. 2
depicting examples of major components of the thin film stack of the printhead.
FIG. 4
is a schematic top plan view illustrating an example of a thin film metal underlay structure that underlies selected portions of the barrier layer of the printhead of
FIGS. 2 and 3
.
FIG. 5
is a schematic top plan view illustrating another example of a thin film metal underlay structure that underlies selected portions of the barrier layer of the printhead of
FIGS. 2 and 3
.
FIG. 6
is a schematic top plan view illustrating a further example of a thin film metal underlay structure that underlies selected portions of the barrier layer of the printhead of
FIGS. 2 and 3
.
FIG. 7
is a schematic top plan view illustrating another example of a thin film metal underlay structure that underlies selected portions of the barrier layer of the printhead of
FIGS. 2 and 3
.
FIG. 8
depicts an example of a printing system that can employ the printhead of FIGS.
2
and
3
.
DETAILED DESCRIPTION OF THE DISCLOSURE
FIG. 1
is a schematic perspective view of one type of ink jet print cartridge
10
that can incorporate a fluid drop ejecting apparatus in accordance with the invention. The print cartridge
10
includes a cartridge body
11
, a printhead
13
, and electrical contacts
15
. The cartridge body
11
contains ink or other suitable fluid that is supplied to the printhead
13
, and electrical signals are provided to the contacts
15
to individually energize ink drop generators to eject a droplet of fluid from a selected nozzle
17
. The print cartridge
10
can be a disposable type that contains a substantial quantity of ink within its body
11
. Another suitable print cartridge may be of the type that receives ink from an external ink supply that is mounted on the print cartridge or fluidically connected to the print cartridge by a conduit such as a tube.
While the disclosed structures are described in the context of ink drop jetting, it should be appreciated that the disclosed structures can be employed for drop jetting of other fluids.
Referring to
FIG. 2
, set forth therein is an unscaled schematic perspective view of an example of the ink jet printhead
13
which generally includes a silicon substrate
21
and an integrated circuit thin film stack
25
of thin film layers formed on the silicon substrate
21
. The thin film stack
25
implements ink firing heater resistors
56
and associated electrical circuitry such as drive circuits and addressing circuits, and can be formed pursuant to integrated circuit fabrication techniques. Byway of illustrative example, the thin film heater resistors
56
are located in columnar arrays along longitudinal ink feed edges
21
a
of the silicon substrate
21
.
An ink barrier layer
27
is disposed over the thin film stack
25
, and an orifice or nozzle plate
29
containing the nozzles
17
is in turn laminarly disposed on the ink barrier layer
27
. Gold bond pads
35
engagable for external electrical connections are disposed at the ends of the thin film stack
25
and are not covered by the ink barrier layer
27
. The ink barrier layer
27
is formed, for example, of a dry film that is heated and pressure laminated to the thin film stack
25
and photodefined to form therein ink chambers
31
, ink channels
33
a
,
33
b
, and barrier islands
41
,
43
. By way of illustrative example, the barrier layer material comprises an acrylate based photopolymer dry film such as the Parad brand photopolymer dry film obtainable from E.l. duPont de Nemours and Company of Wilmington, Del. Similar dry films include other duPont products such as the Riston brand dry film and dry films made by other chemical providers. The orifice plate
29
comprises, for example, a planar substrate comprised of a polymer material and in which the orifices
17
are formed by laser ablation, for example as disclosed in commonly assigned U.S. Pat. No. 5,469,199, incorporated herein by reference. The orifice plate can also comprise, by way of further example, a plated metal such as nickel.
The ink chambers
31
in the ink barrier layer
27
are more particularly disposed over respective ink firing resistors
56
formed in the thin film stack
25
, and each ink chamber
31
is defined by the edge or wall of a chamber opening formed in the barrier layer
27
. The ink channels
33
a
,
33
b
are defined by barrier features formed in the barrier layer
27
including barrier peninsulas
37
and barrier channel islands
41
, and are integrally joined to respective ink firing chambers
31
. Barrier reef islands
43
can be located along the feed edge
21
a
.
The orifices
17
in the orifice plate
29
are disposed over respective ink chambers
31
, such that an ink firing resistor
56
, an associated ink chamber
31
, and an associated orifice
17
form an ink drop generator
40
.
The ink barrier layer
27
and orifice plate
29
can alternatively be implemented as an integral ink channel and orifice structure, for example as described in U.S. Pat. No. 6,162,589.
FIG. 3
is a schematic cross-sectional view of a portion of the thin film stack
25
depicting examples of major components of the thin film stack
25
. An active device substructure
51
embodying active devices such as FET drive circuits is formed on the silicon substrate
21
. A patterned tantalum/aluminum (Ta/Al) resistive layer
53
is disposed on the active device substructure
51
, and a patterned aluminum (Al) layer
55
is on the tantalum/aluminum layer. Heater resistors
56
are defined by gaps
55
a
in traces in the aluminum layer
55
whereby the portion of the resistive layer
53
that underlies the gap
55
a
comprises the heater resistor
56
. A silicon nitride (Si3N4) layer
57
and a silicon carbide (SiC) layer
59
are passivation layers disposed over the aluminum layer
55
. A tantalum layer
61
on the silicon carbide layer
59
functions as a mechanical passivation layer in the ink chambers
31
that absorbs the impact of bubble collapse.
As more particularly depicted in
FIGS. 4-7
, the thin film stack
25
includes a thin film metal underlay structure formed in the aluminum layer
55
or tantalum layer
61
, or both, and underlying at least the barrier reef islands
43
and extending laterally toward the ink chambers
31
. The thin film metal structure more particularly comprises one or more metal regions that are in or occupy a region of the printhead that underlies the barrier reef islands
43
and can extend laterally toward the ink chambers
31
. Such thin film metal structure can improve the adhesion between the thin film stack and the portions of the barrier layer
27
that overlie the thin film metal underlay structure.
FIG. 4
is an unscaled partial top plan view illustrating an embodiment wherein the thin film metal structure comprises an elongated metal strip
45
a
disposed beneath the barrier reef islands
43
. The metal strip
45
a
extends longitudinally so as to span or subtend the desired barrier reef islands for example. A further elongated metal strip
45
b
can also be provided under the channel islands
41
. The metal strips
45
a
,
45
b
can be formed in the aluminum layer
55
or the tantalum layer
61
, or both.
FIG. 5
is an unscaled partial top plan view illustrating an embodiment wherein the thin film metal structure comprises a metal slab
45
c
that underlies the barrier reef islands
43
and extends laterally to the ink chambers
31
, for example, or to lesser lateral extent. The metal slab
45
c
can be considered as being a wider version of the metal strip
45
a
of FIG.
4
. The metal slab
45
c
extends longitudinally so as to span or subtend the desired barrier reef islands
43
or barrier peninsulas
37
, for example. The metal slab
45
c
can be formed in the tantalum layer
61
and/or the aluminum layer
55
of the thin film stack
25
.
FIG. 6
is an unscaled partial top plan view illustrating an embodiment wherein the thin film metal structure comprises an array of metal islands or pads
45
d
in a region that underlies the barrier reef islands
43
and can extend inwardly toward the ink chamber
31
. The metal islands or pads
45
d
thus underlie at least the barrier reef islands
43
, and can underlie portions of the barrier peninsulas
37
and the channel islands
41
. The metal islands or pads
45
d
can be formed in the aluminum layer
55
or the tantalum layer
61
, or both. The metal pads can be triangular, cylindrical, cross-shaped, or any other shape. The metal pads
45
d
can have respective areas that are smaller than the area of the smallest one of the barrier reef islands
43
, for example. Alternatively, the metal pads
45
d
can be larger than the barrier reef islands
43
.
FIG. 7
is an unscaled partial top plan view illustrating embodiments wherein the thin film metal structure comprises a set of one or more metal buttons
45
e
formed in the aluminum layer
55
or the tantalum layer
61
and located beneath a corresponding barrier reef island
43
. A set of one or more buttons can additionally be located beneath a selected channel island
41
. The button(s)
45
e
can be of any selected shape.
FIG. 7
depicts various configurations and arrangements of buttons for illustrative purposes, and it should be appreciated that in any given printhead, a uniform configuration and arrangement of buttons can be employed.
FIG. 8
is a perspective view of an exemplary implementation of an ink jet printing system
110
in which the disclosed print cartridge
10
can be employed. The printing system
110
includes a printer portion
111
having at least one print cartridge
10
installed in a scanning carriage
113
. The printer portion
111
includes a media tray
115
for receiving print media
117
. As a sheet of print media is stepped through a print zone in the printer portion
111
, the scanning carriage moves the print cartridge(s)
10
across the print media. The printer portion
111
selectively activates drop generators of the printhead of the print cartridge
10
to deposit ink on the print media to thereby accomplish printing.
The foregoing has thus been a disclosure of a fluid drop emitting device that is useful in inkjet printing as well as other drop emitting applications such as medical devices, and techniques for making such fluid drop emitting device.
Although the foregoing has been a description and illustration of specific embodiments of the invention, various modifications and changes thereto can be made by persons skilled in the art without departing from the scope and spirit of the invention as defined by the following claims.
Claims
- 1. A fluid drop ejecting apparatus comprising:a substrate having a fluid feed edge; a thin film stack including a plurality of heater resistors formed on said substrate; a patterned fluid barrier layer disposed on said thin film stack; respective fluid chambers formed in said fluid barrier layer over respective heater resistors; respective nozzles disposed over said respective fluid chambers and said heater resistors; fluid feed features formed in said fluid barrier layer adjacent said fluid feed edge; a thin film metal structure formed in a metal layer of said thin film stack and located beneath said fluid feed features.
- 2. The fluid drop ejecting apparatus of claim 1 wherein said thin film metal structure comprises a metal region that underlies said fluid feed features adjacent said fluid feed edge.
- 3. The fluid drop ejecting apparatus of claim 2 wherein said metal region comprises a metal strip.
- 4. The fluid drop ejecting apparatus of claim 2 wherein said metal region comprises a metal slab that extends toward said fluid chambers.
- 5. The fluid drop ejecting apparatus of claim 2 wherein said metal region comprises a tantalum region.
- 6. The fluid drop ejecting apparatus of claim 5 wherein said tantalum region is in contact with said barrier layer.
- 7. The fluid drop ejecting apparatus of claim 2 wherein said metal region comprises an aluminum region.
- 8. The fluid drop ejecting apparatus of claim 1 wherein said thin film metal structures comprises a plurality of metal regions.
- 9. The fluid drop ejecting apparatus of claim 8 wherein said metal regions comprise tantalum regions.
- 10. The fluid drop ejecting apparatus of claim 9 wherein said tantalum regions are in contact with said barrier layer.
- 11. The fluid drop ejecting apparatus of claim 8 wherein said metal regions comprise aluminum regions.
- 12. The fluid drop ejecting apparatus of claim 8 wherein said metal regions occupy a region that underlies said fluid feed features and extends toward said fluid chambers.
- 13. A fluid drop ejecting apparatus comprising:a substrate having a fluid feed edge; a thin film stack including a plurality of heater resistors formed on said substrate; a patterned fluid barrier layer disposed on said thin film stack; respective fluid chambers formed in said fluid barrier layer over respective heater resistors; respective nozzles disposed over said respective fluid chambers and said heater resistors; barrier islands formed in said fluid barrier layer adjacent said fluid feed edge; and a thin film metal structure formed in a metal layer of said thin film stack and located beneath said barrier islands.
- 14. The fluid drop ejecting apparatus of claim 13 wherein said thin film metal structure comprises a metal region that underlies said barrier islands.
- 15. The fluid drop ejecting apparatus of claim 14 wherein said metal region comprises a metal strip.
- 16. The fluid drop ejecting apparatus of claim 14 wherein said metal region comprises a metal slab that extends toward said fluid chambers.
- 17. The fluid drop ejecting apparatus of claim 14 wherein said metal region comprises a tantalum region.
- 18. The fluid drop ejecting apparatus of claim 17 wherein said tantalum region is in contact with said barrier layer.
- 19. The fluid drop ejecting apparatus of claim 14 wherein said metal region comprises an aluminum region.
- 20. The fluid drop ejecting apparatus of claim 13 wherein said thin film metal structure comprises a plurality of metal regions.
- 21. The fluid drop ejecting apparatus of claim 20 wherein said metal regions comprise tantalum regions.
- 22. The fluid drop ejecting apparatus of claim 21 wherein said tantalum regions are in contact with said barrier layer.
- 23. The fluid drop ejecting apparatus of claim 20 wherein said metal regions comprise aluminum regions.
- 24. The fluid drop ejecting apparatus of claim 20 wherein said metal regions occupy a region that underlies said barrier islands and extends toward said fluid chambers.
- 25. An ink jet printhead comprising:a substrate having a fluid feed edge; a thin film stack formed on said substrate, said thin film stack including an aluminum layer, a tantalum layer, and heater resistors; a patterned fluid barrier layer disposed on said tantalum layer; respective fluid chambers formed in said fluid barrier layer over respective heater resistors; respective nozzles disposed over said respective fluid chambers and said heater resistors; barrier islands formed in said fluid barrier layer adjacent said fluid feed edge; and a thin film metal structure disposed beneath said barrier islands and formed in at least one of said aluminum layer and said tantalum layer.
- 26. The ink jet printhead of claim 25 wherein said thin film metal structure comprises a metal region that underlies said barrier islands.
- 27. The ink jet printhead of claim 26 wherein said metal region comprises a metal strip.
- 28. The ink jet printhead of claim 26 wherein said metal region comprises a metal slab that extends toward said fluid chambers.
- 29. The ink jet printhead of claim 26 wherein said metal region comprises a tantalum region that is in contact with said barrier islands.
- 30. The ink jet printhead of claim 25 wherein said thin film metal structure comprises a plurality of metal regions.
- 31. The ink jet printhead of claim 30 wherein said metal regions comprise tantalum regions that are in contact with said barrier islands.
- 32. The ink jet printhead of claim 30 wherein said metal regions occupy a region that underlies said barrier islands and extends toward said fluid chambers.
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Number |
Name |
Date |
Kind |
5463413 |
Ho et al. |
Oct 1995 |
A |
5469199 |
Allen et al. |
Nov 1995 |
A |
6007188 |
MacLoed et al. |
Dec 1999 |
A |
6162589 |
Chen et al. |
Dec 2000 |
A |