U.S. patent application number 12/081626 was filed with the patent office on 2008-12-18 for method for producing piezoelectric film actuator, and composite structure having piezoelectric layer.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Toshihiro Ifuku, Makoto Kurotobi, Takehito Okabe, Nobuhiko Sato, Kenichi Takeda.
Application Number | 20080307622 12/081626 |
Document ID | / |
Family ID | 35995511 |
Filed Date | 2008-12-18 |
United States Patent
Application |
20080307622 |
Kind Code |
A1 |
Okabe; Takehito ; et
al. |
December 18, 2008 |
Method for producing piezoelectric film actuator, and composite
structure having piezoelectric layer
Abstract
A method for producing a piezoelectric film actuator is
provided. This method includes the steps of preparing an
intermediate transfer member having a porous layer formed thereon,
with a vibrating plate and a piezoelectric layer being provided on
the porous layer; bonding the vibrating plate to a nozzle substrate
to form a composite structure; and separating the intermediate
transfer member from the composite structure at the porous layer to
transfer the vibrating plate and the piezoelectric layer to the
nozzle substrate.
Inventors: |
Okabe; Takehito;
(Atsugi-shi, JP) ; Sato; Nobuhiko;
(Sagamihara-shi, JP) ; Kurotobi; Makoto;
(Yokohama-shi, JP) ; Takeda; Kenichi;
(Yokohama-shi, JP) ; Ifuku; Toshihiro;
(Yokohama-shi, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
35995511 |
Appl. No.: |
12/081626 |
Filed: |
April 18, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11218515 |
Sep 6, 2005 |
|
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12081626 |
|
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Current U.S.
Class: |
29/25.35 ;
29/25.42; 310/158 |
Current CPC
Class: |
Y10T 29/42 20150115;
H01L 41/332 20130101; Y10T 29/49126 20150115; Y10T 29/49128
20150115; B41J 2/1629 20130101; B41J 2/1643 20130101; B41J 2/1623
20130101; Y10T 29/4913 20150115; B41J 2/1632 20130101; B41J 2/1646
20130101; B41J 2/1642 20130101; H01L 41/1876 20130101; Y10T
29/49155 20150115; Y10T 29/435 20150115; B41J 2/161 20130101; B41J
2/1628 20130101 |
Class at
Publication: |
29/25.35 ;
29/25.42; 310/158 |
International
Class: |
H01L 41/22 20060101
H01L041/22 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 6, 2004 |
JP |
2004-258366 |
Claims
1. A method for producing a piezoelectric film actuator, comprising
the steps of: preparing a first substrate having a porous layer
formed thereon, with a vibrating plate and a piezoelectric layer
being provided on the porous layer; bonding the vibrating plate to
a second substrate to form a composite structure; and separating
the first substrate from the composite structure at the porous
layer to transfer the vibrating plate and the piezoelectric layer
to the second substrate.
2. The method for producing a piezoelectric film actuator according
to claim 1, wherein the first substrate comprises silicon.
3-10. (canceled)
11. The method for producing a piezoelectric film actuator
according to claim 1, wherein the piezoelectric layer is formed by
etching using a resist film as a mask.
12. The method for producing a piezoelectric film actuator
according to claim 1, wherein the vibrating plate has a multilayer
structure.
13-20. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to methods for producing
piezoelectric film actuators for use in, for example,
liquid-ejecting heads.
[0003] 2. Description of the Related Art
[0004] Known liquid-ejecting heads are disclosed in, for example,
the following publications.
(1) Japanese Patent Laid-Open No. 2002-134806
[0005] According to this publication, a vibrating plate composite
and piezoelectric films are provided to cavity parts by forming the
piezoelectric films on an intermediate transfer member, bonding the
vibrating plate composite to the piezoelectric films, and
separating the intermediate transfer member to transfer the
piezoelectric films to the vibrating plate composite.
(2) Japanese Patent Laid-Open No. 2002-234156
[0006] This publication discloses a piezoelectric element composite
including a single-crystal or polycrystalline vibrating plate
sandwiched between oxide layers and uniaxial-crystal or
single-crystal piezoelectric films.
[0007] A liquid-ejecting head is provided by sequentially forming a
SiO.sub.2 film, a YSZ film, Pt films, and PZT films, which function
as piezoelectric films, on an SOI substrate, partially etching the
Si substrate to form pressure chambers, and bonding an intermediate
Si substrate and an orifice plate that constitute parts of the
pressure chambers.
(3) Japanese Patent No. 2976479
[0008] This publication discloses a liquid-ejecting head including
a nozzle substrate having nozzles, a silicon substrate having
cavities communicating with the nozzles and thin film parts
corresponding to the cavities, and pressure generators formed on
the thin film parts integrally without any bonding step.
(4) Japanese Patent Laid-Open No. 10-286953
[0009] According to this publication, electrodes, lead-based
dielectric layers, electrodes, and a vibrating plate are
sequentially formed on a MgO substrate. After resin or glass for
forming pressure chambers are provided on the vibrating plate, the
MgO substrate is partially or completely removed. The pressure
chambers are formed by, for example, patterning.
[0010] First Problem: According to Japanese Patent Laid-Open No.
2002-134806, after the piezoelectric films are transferred to the
vibrating plate composite, a wiring step is required to provide,
for example, electrical paths to the piezoelectric films. This step
involves limitations such as the need for avoiding the breakage of
ink cavities. Such limitations make it difficult to support
flexibility in, for example, finer processing and heat
processes.
[0011] Second Problem: The liquid-ejecting head according to
Japanese Patent Laid-Open No. 2002-234156 has the following two
problems.
[0012] (1) Use of an SOI Wafer leads to high production cost
because the wafer is more expensive than general silicon
wafers.
[0013] (2) If the selective etching of the Si wafer for forming
pressure chambers is performed by alkali etching to ensure etching
selectivity to the buried silicon oxide, the openings of the
pressure chambers become larger than the areas thereof adjacent to
the vibrating plate. This is disadvantageous in arranging the
pressure chambers at higher density.
[0014] Third Problem: Japanese Patent No. 2976479 is
disadvantageous in terms of the thickness control of the vibrating
plate. As the amount of each droplet ejected is reduced to improve
the resolution and gradation of ink jet printers, the number of ink
dots per unit area on printing paper is increased. Accordingly, the
responsiveness of the vibrating plate must be enhanced to maintain
printing speed by, for example, reducing the thickness of the
vibrating plate. The reduction in the thickness of the silicon
vibrating plate, however, may cause a problem in thickness control
because selective etching based on the difference in impurity
concentration has low selectivity.
[0015] Fourth Problem: According to Japanese Patent Laid-Open No.
10-286953, the use of the MgO substrate makes it difficult to form
peripheral circuitry, such as a drive circuit, using single-crystal
silicon as an active layer. This is disadvantageous in terms of the
finer processing of ink jet heads, which is accompanied by higher
density. Because ink jet heads with higher densities require
higher-speed drive circuits, it is desired to form peripheral
circuitry on single-crystal silicon, which is a high-mobility
material. If a Si substrate is used, however, the vibrating plate
cannot be made of Si. This causes difficulty in achieving a
high-quality single-crystal vibrating plate with good
sensitivity.
SUMMARY OF THE INVENTION
[0016] In light of the above problems, the present invention
provides a piezoelectric film actuator that includes a vibrating
plate with finely controlled thickness, may be produced without the
use of an SOI wafer, and is insusceptible to heat processes, and
also provides a method for producing the piezoelectric film
actuator.
[0017] A method for producing a piezoelectric film actuator
according to the present invention includes the steps of preparing
a first substrate having a porous layer formed thereon, with a
vibrating plate and a piezoelectric layer being provided on the
porous layer; bonding the vibrating plate to a second substrate to
form a composite structure; and separating the first substrate from
the composite structure at the porous layer to transfer the
vibrating plate and the piezoelectric layer to the second
substrate.
[0018] In yet another aspect, the present invention relates to a
composite structure including a first substrate on which a porous
layer is disposed; a piezoelectric layer; a vibrating plate
disposed between the porous layer and the piezoelectric layer; and
a second substrate to which the vibrating plate is bonded, wherein
the porous layer is disposed between the first substrate and the
vibrating plate.
[0019] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings, in which like reference
characters designate the same or similar parts throughout the
figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention and, together with the description, serve to explain
the principles of the invention.
[0021] FIGS. 1A to 1C are diagrams showing the main steps of a
method for producing a piezoelectric film actuator according to the
present invention.
[0022] FIGS. 2A to 2C are diagrams showing the steps of preparing a
nozzle substrate according to the present invention.
[0023] FIGS. 3A to 3D are diagrams showing the steps of producing a
piezoelectric film actuator with a piezoelectric substrate and the
nozzle substrate according to the present invention.
[0024] FIGS. 4A and 4B are diagrams of a piezoelectric substrate
according to an example of the present invention after the
formation of resist films.
[0025] FIGS. 5A and 5B are diagrams of the piezoelectric substrate
in the step following the step in FIGS. 4A and 4B.
DESCRIPTION OF THE EMBODIMENTS
[0026] Embodiments of the present invention will now be described
in detail with reference to the drawings. FIGS. 1A to 1C are
diagrams showing the main steps of a method for producing a
piezoelectric film actuator (hereinafter also simply referred to as
an actuator) according to the present invention. As shown in FIGS.
1A to 1C, the method for producing a piezoelectric film actuator
according to the present invention includes the main steps of
forming a porous silicon layer on a first substrate made of silicon
(hereinafter also referred to as an intermediate transfer member);
forming a vibrating plate on the porous layer; and forming a
piezoelectric layer on the vibrating plate. This method further
includes the steps of bonding the vibrating plate to a second
substrate to form a composite-structure; and separating the
intermediate transfer member from the composite structure at the
porous layer to transfer the vibrating plate and the piezoelectric
layer to the second substrate. The individual steps according to
the present invention will be specifically described below.
1. Formation of Vibrating Plate, Piezoelectric Film, and
Electrode
(1) Formation of Porous Silicon Layer (FIG. 1A)
[0027] Referring to FIG. 1A, a porous Si layer 11 is formed on one
of the main surfaces, which are polished, of a single-crystal Si
substrate 10 having a thickness of 625 .mu.m. The porous layer 11
is intended to facilitate the removal of the intermediate transfer
member after the vibrating plate and the piezoelectric film are
bonded to cavities. The porous layer 11 is formed by, for example,
anodizing, in which current is applied with the main surface of the
single-crystal Si substrate 10 as an anode in an aqueous HF
solution.
[0028] The thickness of the porous layer 11 is defined by, for
example, controlling the time for anodizing. The porous layer 11
may have a bilayer structure including an exposed first layer with
lower porosity and an underlying second layer with higher porosity
than the first layer. The bilayer structure allows stress to
concentrate at the part of the second layer in the vicinity of the
interface between the first and second layers so that they can be
separated selectively at that part.
[0029] The thickness' of the porous layer 11 is not particularly
limited. The porous layer 11 may have a thickness of 0.01 to 200
.mu.m, particularly 0.5 to 10 .mu.m; excessive thickness causes
large wafer warpage which may interfere with the process. If the
porous layer 11 has the bilayer structure, the first layer
generally has a thickness of 20 .mu.m or less, particularly 10
.mu.m or less, and the second layer generally has a thickness of 10
.mu.m or less, particularly 5 .mu.m or less. The porosity of the
first layer is generally 60% or less, particularly 30% or less;
high porosity degrades the quality (e.g., crystal defect density
and surface roughness) of an epitaxial layer.
[0030] The porosity may be determined according to the change in
wafer weight before and after the anodizing and the thickness of
the porous layer 11.
(2) Formation of Vibrating Plate (FIG. 1B)
[0031] After the anodizing, a vibrating plate 12 is formed on the
porous layer 11. The vibrating plate 12 may be made of Si, though
the material used is not limited to Si. The vibrating plate 12 may
be formed by, for example, thermal CVD, plasma-enhanced CVD, MBE,
or liquid-phase epitaxy.
[0032] The vibrating plate 12 is made of a material with a Young's
modulus of 50 GPa or more. Examples of such a material include
stainless steel, Ti, zirconia, Si, Cu, SiO.sub.2, glass, and Cr.
The vibrating plate 12 may have either a monolayer structure or a
multilayer structure. For the multilayer structure, the total
Young's modulus must be 50 GPa or more. The vibrating plate 12 may
have a thickness of 0.5 to 20 .mu.m, particularly 1 to 10 .mu.m.
The material for the vibrating plate 12 may be doped with a slight
amount of metal such as Y or B.
[0033] In particular, Si may be used for the vibrating plate 12
since a drive circuit, for example, can be formed in a normal Si
process.
(3) Formation of Pressure Generator (FIG. 1C)
[0034] A piezoelectric layer made of PZT and accompanying electrode
layers are formed on the vibrating plate 12, which is a nonporous
single-crystal film, by, for example, the following process.
[0035] A common electrode layer 21, a piezoelectric layer 20, and
an individual electrode layer 22 are formed on the vibrating plate
12 by sputtering or ion plating. The common electrode layer 21 is
made of, for example, Pt, Cr, or Ni and has a thickness of 1 .mu.m.
The piezoelectric layer 20 is made of PZT and has a thickness of 10
.mu.m. The individual electrode layer 22 is made of, for example,
Pt, Cr, or Ni. A patterned resist film is formed on the individual
electrode layer 22. The common electrode layer 21, the individual
electrode layer 22, and the piezoelectric layer 20 are etched using
the resist film as a mask by ion etching or reactive ion etching to
form common electrodes 21', individual electrodes 22', and
piezoelectric layers 20'. Additionally, vibrating parts and wiring
parts are formed at the same time.
2. Formation of Nozzle and Production of Ink Jet Head
(4) Formation of Nozzle Substrate (FIGS. 2A to 2C)
[0036] Next, a process for preparing a nozzle substrate A2 and its
structure will be described with reference to FIGS. 2A to 2C. The
nozzle substrate A2 may be made of any material that can form
nozzles. Examples of the material for the nozzle substrate A2
include glass, resin, and single-crystal Si. In particular, a
single-crystal Si substrate may be used because it has the same
thermal expansion coefficient as the piezoelectric substrate A1 and
good resistance to aging. Nozzles are formed by, for example, the
following process.
[0037] Referring to FIGS. 2A to 2C, a single-crystal Si substrate
60 with both surfaces thereof polished that has a thickness of 100
.mu.m is prepared. SiO.sub.2 films 61 having a thickness of 0.1
.mu.m are formed on both surfaces of the single-crystal Si
substrate 60 by thermal oxidation. A resist layer 63 is formed on
the surface of one SiO.sub.2 film 61 other than square regions 64
having the same dimensions as the openings of cavities to be formed
on the nozzle substrate A2 such that the square regions 64 have
sides in the [110] directions, while another resist layer 63 is
formed on the overall surface of the other SiO.sub.2 film 61 (FIG.
2A).
[0038] The portions of the SiO.sub.2 film 61 in the square regions
64 are removed by etching, and then the resist layers 63 are
removed. Subsequently, the single-crystal Si substrate 60 is
anisotropically etched with an aqueous solution of pyrocatechol and
ethylenediamine (FIG. 2B), and the SiO.sub.2 films 61 are removed.
The resultant nozzles 70 have outlets 71 smaller than the cavity
openings (FIG. 2C).
[0039] The nozzle substrate A2 may also be formed by laminating two
substrates made of different materials or the same material. In
this case, a cavity portion and a nozzle portion can be separately
formed. Examples of the material used include glass, resin, and
single-crystal Si. In particular, a single-crystal Si substrate may
be used because it has the same thermal expansion coefficient as
the piezoelectric substrate A1 and good resistance to aging.
(5) Bonding of Piezoelectric Substrate and Nozzle Substrate (FIG.
3A)
[0040] The piezoelectric substrate A1 and the nozzle substrate A2
thus produced are bonded to form a composite structure such that
the piezoelectric layers 20' and the nozzle outlets 71 are directed
to the ejection side. These substrates A1 and A2 may be bonded by,
for example, anodic bonding, active metal brazing, or the use of
adhesive or covalent bonding.
[0041] Even an adhesive with low heat resistance may be used since
the drive circuit, for example, has already been formed.
(6) Separation of Intermediate Transfer Member from Vibrating Plate
and Piezoelectric Element (FIG. 3B)
[0042] Referring to FIG. 3B, the intermediate transfer member
(single-crystal Si substrate) 10 is separated from the composite
structure, which is an actuator including the vibrating plate 12
and the piezoelectric layers 20' bonded thereto, at the porous
layer 11 to transfer the vibrating plate 12 and the piezoelectric
layers 20' to the nozzle substrate A2. The intermediate transfer
member 10 may be separated by, for example, destroying the porous
layer 11 mechanically or with water jets, or by rapid heating
through laser irradiation.
[0043] Japanese Patent No. 2877800, to the assignee of the present
application, discloses a method for separating a composite member,
such as bonded substrates, with a fluid.
(7) Removal of Porous Layer (FIG. 3C)
[0044] If the porous layer 11 is not exposed after the separation
of the intermediate transfer member 10, the porous layer 11 is
exposed by, for example, lapping, grinding, polishing, or etching.
This exposure step is not required if the porous layer 11 has
already been exposed.
[0045] Subsequently, the porous layer 11 is etched with, for
example, a hydrofluoric acid solution. The etchant used may be a
hydrofluoric acid solution particularly if the porous layer 11 is
oxidized in advance. The etchant used, however, is not limited to a
hydrofluoric acid solution; an aqueous alkali solution, for
example, may be used if no oxide is formed on the pore walls of the
porous layer 11 or if oxide is removed in advance.
(8) Formation of Penetrating Electrode (FIG. 3D)
[0046] After the removal of the porous layer 11, if necessary,
electrical paths to the pressure generators are provided from above
since the pressure generators are disposed in the nozzle substrate
A2. Penetrating electrodes 13 may be readily provided if the
vibrating plate 12 is made of a thin film having a thickness of
about 0.2 .mu.m.
[0047] The penetrating electrodes 13 may be formed by any method
with a metal such as Ni, Sn, W, Fe, Cu, Au, or Pt.
Example
[0048] Next, the present invention will be described with reference
to an example below, though the invention is not limited to the
example.
[0049] FIGS. 3A to 3D, 4A and 4B, and 5A and 5B are schematic
diagrams showing the steps of a method for producing a
liquid-ejecting head including a piezoelectric film actuator
according to a specific example of the present invention.
(1) Formation of Porous Silicon
[0050] In the step of forming a porous layer on an intermediate
transfer member, a Si crystal substrate having a thickness of 625
.mu.m was used as the intermediate transfer member. A porous Si
layer was provided by forming an exposed first layer under the
conditions of a current density of 8 mA/cm.sup.2 and a processing
time of 5 to 11 minutes and then forming an underlying second layer
under the conditions of a current density of 23 to 33 mA/cm.sup.2
and a processing time of 80 seconds to 2 minutes in a mixed
solution of an aqueous HF solution (HF concentration: 49% by
weight) and ethanol in a ratio of 2:1 by volume. The first layer
had a porosity of about 20% and a thickness of about 6 .mu.m while
the second layer had a porosity of about 50% and a thickness of
about 3 .mu.m.
(2) Formation of Vibrating Plate
[0051] A single-crystal Si layer was allowed to grow on the porous
Si layer as a vibrating plate by CVD. In the initial growth stage,
a non-porous film was allowed to grow at a low rate by supplying a
slight amount, namely 20 nm/min or less, of starting material to
seal pores on the surface of the porous Si layer before a
single-crystal Si layer having a thickness of 10 .mu.m was formed
at a growth rate of 1 .mu.m/min.
(3) Formation of Pressure Generator
[0052] FIGS. 4A and 4B are diagrams of the piezoelectric substrate
A1 after the formation of resist films. FIG. 4A is a top view of
the piezoelectric substrate A1, and FIG. 4B is a sectional view
taken along line 4B-4B' in FIG. 4A. A common electrode layer 21, a
piezoelectric layer 20, and an individual electrode layer 22 were
formed on the vibrating plate 12 by sputtering or ion plating. The
common electrode layer 21 was made of, for example, Pt, Cr, or Ni
and had a thickness of 1 .mu.m. The piezoelectric layer 20 was made
of PZT and had a thickness of 10 .mu.m. The individual electrode
layer 22 was made of, for example, Pt, Cr, or Ni. Resist films 23
were formed on the individual electrode layer 22. These resist
films 23 had dimensions of 425 .mu.m by 800 .mu.m, and the sides
thereof were aligned in the directions indicated by arrows X-X' and
Y-Y' in the drawing.
[0053] FIGS. 5A and 5B are diagrams of the piezoelectric substrate
A1 in the subsequent step. FIG. 5A is a top view of the
piezoelectric substrate A1, and FIG. 5B is a sectional view taken
along line 5B-5B' in FIG. 5A. The common electrode layer 21, the
individual electrode layer 22, and the piezoelectric layer 20,
shown in FIGS. 4A and 4B, were etched by ion etching or reactive
ion etching using the pattern of the resist films 23 to form common
electrodes 21', individual electrodes 22', and piezoelectric layers
20' (pressure generators 26).
(4) Formation of Nozzle Substrate
[0054] Referring to FIGS. 2A to 2C, a single-crystal Si substrate
60 with both surfaces thereof polished that had a thickness of 100
.mu.m was prepared. SiO.sub.2 films 61 having a thickness of 0.1
.mu.m were formed on both surfaces of the single-crystal Si
substrate 60 by thermal oxidation. A resist layer 63 was formed on
the surface of one SiO.sub.2 film 61 other than square regions 64
having the same dimensions as the openings of cavities to be formed
on the nozzle substrate A2 such that the square regions 64 had
sides in the [110] directions, while another resist layer 63 was
formed on the overall surface of the other SiO.sub.2 film 61 (FIG.
2A). The portions of the SiO.sub.2 film 61 in the square regions 64
were removed by etching, and then the resist layers 63 were
removed. Subsequently, the single-crystal Si substrate 60 was
anisotropically etched with an aqueous solution of pyrocatechol and
ethylenediamine (FIG. 2B), and the SiO.sub.2 films 61 were removed.
The resultant nozzles 70 had outlets 71 smaller than the cavity
openings (FIG. 2C).
(5) Bonding
[0055] In the subsequent step of bonding the vibrating plate and
the pressure generators disposed on the intermediate transfer
member to the nozzle substrate, the piezoelectric substrate A1 and
the nozzle substrate A2 were brought into contact such that the
piezoelectric layers 20' and the nozzle outlets 71 were directed to
the ejection side. These substrates A1 and A2 were subjected to
anodic bonding at 400.degree. C. by applying a voltage of 1,000 V
across the piezoelectric substrate A1, at a minus potential, and
the nozzle substrate A2, at a plus potential.
(6) Separation
[0056] The intermediate transfer member could be readily separated
at the porous layer by exposing the porous layer to a water jet
with a pressure of 15.times.10.sup.4 kPa.
(7) Formation of Electrode
[0057] After etching, a SiO.sub.2 mask was formed on the vibrating
plate, which was etched to a depth of 10 .mu.m from the wafer
surface by dry etching to form openings having dimensions of 10
.mu.m by 10 .mu.m directly over the pressure generators. These
openings were filled with Cu by plating, and the Cu was
mechanically polished to form flat surfaces. The SiO.sub.2 films
were removed to provide electrodes.
[0058] The liquid-ejecting head thus produced could stably eject
liquid at a rate of 11 m/s with a drive voltage of 20 V and a
frequency of 15 kHz.
[0059] According to the present invention, a vibrating plate may be
deposited on an intermediate transfer member to facilitate the
control of thickness of the vibrating plate and provide more
uniform thickness. This has the advantage that the thickness of the
vibrating plate can be freely adjusted according to the performance
of pressure generators. In addition, normal semiconductor equipment
may be used.
[0060] The steps of forming the vibrating plate and the pressure
generators may be separated from the steps of forming a nozzle
substrate having cavities. This has the advantage that the material
for the vibrating plate, as an actuator, may be widely selected,
and the material for the nozzle substrate may be freely
selected.
[0061] In addition, the present invention avoids limitations
associated with handling and heat processes in a wiring step for
forming, for example, a drive circuit because the wiring step is
finished before the bonding of the nozzle substrate.
[0062] Furthermore, the intermediate transfer member may be readily
separated at a porous layer mechanically or by laser irradiation
without damaging the vibrating plate. This allows the recycling of
the intermediate transfer member.
[0063] Accordingly, the present invention can provide a
piezoelectric film actuator capable of producing large displacement
at a low drive voltage, responding quickly, producing large power,
and achieving higher area and density. In addition, the present
invention can provide a long, high-density liquid-ejecting head
capable of producing large displacement at a low drive voltage and
providing quick response and high reliability.
[0064] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all modifications, equivalent
structures and functions.
[0065] This application claims the benefit of Japanese Application
No. 2004-258366 filed Sep. 6, 2004, which is hereby incorporated by
reference herein in its entirety.
* * * * *