JP2001096747A - Ink-jet recording head and its manufacturing method and ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head and an ink-jet recording apparatus in which a break of an elastic plate and a piezoelectric layer at a boundary part between a pressure generation chamber and a peripheral wall is prevented. SOLUTION: The ink-jet recording head has a pressure generation chamber 12 communicating with a nozzle opening 11, and a piezoelectric element 300 comprised of a lower electrode 60, a piezoelectric layer 70 and an upper electrode 80 which is set via an elastic plate 50 in a region corresponding to the pressure generation chamber 12. The ink-jet recording head has an extension part 330 where the lower electrode 60, piezoelectric layer 70 and upper electrode 80 constituting the piezoelectric element 300 extend from inside a region to outside the region opposite to the pressure generation chamber 12. A space part 100 is formed between the piezoelectric layer 70 and the elastic plate 50 at a region opposite to a boundary between an end part of the pressure generation chamber 12 and a peripheral wall. At least the piezoelectric layer 70 and the upper electrode 80 are set extending over the space part 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element formed in a part of a pressure generating chamber communicating with a nozzle opening for discharging an ink drop through an elastic plate, and the ink drop is discharged by displacement of the piezoelectric element. The present invention relates to an ink jet recording head, a method for manufacturing the same, and an ink jet recording apparatus.

[0002]

2. Description of the Related Art A part of a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets is constituted by an elastic plate, and the elastic plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber to cause a pressure from the nozzle opening. Two types of ink jet recording heads that eject ink droplets have been commercialized, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and the other using a flexural vibration mode piezoelectric actuator. ing.

[0003] In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric element into contact with an elastic plate, so that a head suitable for high-density printing can be manufactured. There is a problem in that a difficult process of cutting into a comb shape in accordance with the arrangement pitch of the openings and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required, and the manufacturing process is complicated.

On the other hand, in the latter, a piezoelectric element can be formed on an elastic plate by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of the pressure generating chamber and firing the green sheet. In addition, there is a problem that a certain area is required due to the use of flexural vibration, and that high-density arrangement is difficult.

On the other hand, in order to solve the latter disadvantage of the recording head, a uniform piezoelectric material layer is formed by a film forming technique over the entire surface of the elastic plate as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which the piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by a lithography method, and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

According to this, the operation of attaching the piezoelectric element to the elastic plate becomes unnecessary, and not only can the piezoelectric element be manufactured by the precise and simple method of lithography, but also the thickness of the piezoelectric element can be reduced. There is an advantage that it can be made thin and can be driven at high speed.

[0007]

However, in the above-described structure, the piezoelectric element generally extends to the peripheral wall of the pressure generating chamber. Since stress concentrates on the piezoelectric element at the boundary with the peripheral wall, there is a problem that the elastic plate and the piezoelectric layer are broken.

In view of such circumstances, the present invention provides an ink jet recording head and an ink jet recording apparatus in which the elastic plate and the piezoelectric layer are prevented from being broken at the boundary between the pressure generating chamber and the peripheral wall. Make it an issue.

[0009]

According to a first aspect of the present invention, there is provided a pressure generating chamber communicating with a nozzle opening, and a pressure generating chamber provided in an area corresponding to the pressure generating chamber via an elastic plate. In an ink jet recording head including a lower electrode, a piezoelectric layer, and a piezoelectric element including an upper electrode, an area in which the lower electrode, the piezoelectric layer, and the upper electrode constituting the piezoelectric element face the pressure generating chamber. From the piezoelectric layer and the elastic plate in a region facing the boundary between the end of the pressure generating chamber and the peripheral wall of the extended portion. An ink jet recording head having a space portion, wherein at least the piezoelectric layer and the upper electrode extend over the space portion.

In the first aspect, since the space is provided in the extension of the piezoelectric element, the elastic plate and the extension in the area corresponding to the boundary between the end of the pressure generating chamber and the peripheral wall are destroyed. Can be prevented.

A second aspect of the present invention is the ink jet recording head according to the first aspect, wherein the space is formed between the lower electrode and the elastic plate.

In the second aspect, since the space is formed between the lower electrode of the extending portion and the elastic plate, the elasticity at the boundary between the end of the pressure generating chamber and the peripheral wall due to the driving of the piezoelectric element. The board can be prevented from being destroyed.

According to a third aspect of the present invention, in the second aspect, the lower electrode extending across the space has an inverted concave cross section. In the head.

In the third aspect, the elastic portion can be reliably prevented from being broken by forming the space portion into a predetermined shape.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer has a thickness in a region facing the space and a thickness in a region facing the pressure generating chamber. An ink jet recording head characterized in that it is formed to be thinner than the above.

In the fourth aspect, the displacement of the elastic plate in the region corresponding to the end of the pressure generating chamber and the peripheral wall is not hindered, and the displacement efficiency of the elastic plate is improved.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the piezoelectric element located on the space portion faces a boundary between an end of the pressure generating chamber and a peripheral wall. An ink jet recording head is characterized by being constituted of a thin film formed on a sacrificial layer which is provided in a region and is finally removed.

According to the fifth aspect, the space can be easily formed by the sacrificial layer, and the piezoelectric element can be easily formed by the thin film process.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the thickness of the space portion is between 0.2 μm and 1.0 μm. It is in.

In the sixth aspect, by forming the space portion with a predetermined thickness, the elastic plate in the region corresponding to the space portion is more reliably prevented from being broken.

According to a seventh aspect of the present invention, there is provided an ink jet recording head according to any one of the second to sixth aspects, wherein a protective film is provided on the space side of the lower electrode.

In the seventh aspect, since the surface of the lower electrode in the space is covered with the protective film, the lower electrode is prevented from being broken.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation. An ink jet recording head is formed by a lithography method.

In the eighth aspect, an ink jet recording head having high-density nozzle openings can be manufactured in a large amount and relatively easily.

According to a ninth aspect of the present invention, there is provided an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to eighth aspects.

According to the ninth aspect, it is possible to realize an ink jet recording apparatus in which the ink discharge performance of the head is improved and the density is increased.

According to a tenth aspect of the present invention, an elastic plate, a lower electrode, a piezoelectric layer, and an upper plate are provided in a region corresponding to the pressure generating chamber of the flow path forming substrate in which the pressure generating chamber communicating with the nozzle opening is defined. Electrodes are sequentially formed to form a piezoelectric element, and at the boundary between the end of the pressure generating chamber and the peripheral wall of an extended portion of the piezoelectric element extending from an area facing the pressure generating chamber to outside the area. A method of manufacturing an ink jet recording head, wherein a space is formed between the piezoelectric layer and the elastic plate in a region facing each other, and at least the piezoelectric layer and the upper electrode extend over the space. After the elastic plate is formed on the flow path forming substrate, a sacrificial layer is formed in a region facing the boundary between the end of the pressure generating chamber and the peripheral wall during the formation of the piezoelectric element on the elastic plate. Patterning and removing the sacrificial layer In a method for manufacturing the ink jet recording head is characterized in that a step of forming the space portion.

In the tenth aspect, the space can be relatively easily formed at the boundary between the end of the pressure generating chamber of the extension and the peripheral wall.

An eleventh aspect of the present invention is the method for manufacturing an ink jet recording head according to the tenth aspect, wherein the pattern formation of the sacrificial layer is performed before the formation of the lower electrode. .

In the eleventh aspect, the space can be relatively easily formed between the lower electrode of the extension and the elastic plate.

According to a twelfth aspect of the present invention, in the ink jet recording method according to the eleventh aspect, a protective film is formed on the elastic plate and the sacrifice layer after the sacrifice layer is patterned. In the method of manufacturing the head.

In the twelfth aspect, by providing the protective film, the lower electrode can be protected when the sacrificial layer is removed.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view in the longitudinal direction of a pressure generating chamber.

As shown in the figure, the flow path forming substrate 10 is a single crystal silicon substrate having a plane orientation (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

On one surface of the flow path forming substrate 10, an opening surface is formed, and on the other surface, a zirconium oxide film 52 is formed on a silicon dioxide film 51 previously formed by thermal oxidation, and the silicon dioxide film 51 and the zirconium oxide are formed. An elastic plate 50 including the film 52 is formed.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
A nozzle opening 11 and a pressure generating chamber 12 are formed.

Here, in the anisotropic etching, when the silicon single crystal substrate is immersed in an alkaline solution such as potassium hydroxide, the substrate is gradually eroded, and the first (1) plane is perpendicular to the (110) plane.
An (11) plane and a second (111) plane which forms an angle of about 70 degrees with the first (111) plane and forms an angle of about 35 degrees with the (110) plane appear, and (110) This is performed by utilizing the property that the etching rate of the (111) plane is about 1/180 compared to the etching rate of the plane. By such anisotropic etching, precision processing can be performed based on the depth processing of a parallelogram formed by two first (111) planes and two oblique second (111) planes. , The pressure generating chambers 12 can be arranged at a high density.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic plate 50 substantially through 0. The amount of the elastic plate 50 that is attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed to be narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. In addition,
Half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 11 for ejecting the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, the nozzle openings 11 need to be formed with a groove width of several tens of μm with high accuracy.

Each of the pressure generating chambers 12 and a common ink chamber 31 to be described later are connected to each of the pressure generating chambers 1 of the sealing plate 20 to be described later.
The ink is supplied from a common ink chamber 31 through the ink supply communication port 21 formed at a position corresponding to one end of the pressure generation chamber 12. Distributed to

The sealing plate 20 is provided with an ink supply communication port 21 corresponding to each of the pressure generating chambers 12 described above, and has a thickness of, for example, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. The sealing plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force.
The other surface of the sealing plate 20 forms one wall surface of the common ink chamber 31.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31 and is formed by punching a stainless steel plate having an appropriate thickness according to the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and has one surface constituting one wall surface of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, on the elastic plate 50 on the side opposite to the opening surface of the flow path forming substrate 10, a thickness of, for example, about 0.5 μm
A lower electrode film 60, a piezoelectric layer 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated and formed by a process described later, and the piezoelectric element 30 is formed.
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each of the pressure generating chambers 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric layer 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. That is, the piezoelectric element 30 is discontinuous with the lower electrode film 60.
A lower electrode film 61 for wiring used as a zero wiring is provided for each pressure generating chamber 12, and the lower electrode film 61 for wiring and the upper electrode film 80 are connected by a lead electrode 81. In addition, there is no problem even if this is reversed for convenience of the drive circuit and wiring. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Here, the piezoelectric element 300 and an elastic plate whose displacement is generated by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

Further, the piezoelectric element 300 has a drawer portion 33 extending from the area facing the pressure generating chamber 12 to the outside of the area.
It has 0. In the lead portion 330, the lower electrode film 60 is a bent portion 65 bent in a concave shape straddling the space portion 100 having a substantially rectangular cross section provided at the boundary between the end of the pressure generating chamber 12 and the peripheral wall. . In addition, the piezoelectric layer 70 of the lead portion 330 on the space 100 is thinner than that of the piezoelectric active portion 320.

Here, a process of forming the piezoelectric layer 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIGS. 3 and 4 are longitudinal sectional views of a region facing the pressure generating chamber, and FIG. 5 is a sectional view of a region facing the partition of the pressure generating chamber.

First, as shown in FIG. 3 (a), a wafer of a silicon single crystal
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form a silicon dioxide film 51. After that, a zirconium layer is formed on the silicon dioxide film 51, and then thermally oxidized in a diffusion furnace at, for example, 500 to 1200 ° C. to form a zirconium oxide film 52. In this embodiment, the silicon dioxide film 51 and the zirconium oxide film 52 are used as the elastic plate 50.

Next, as shown in FIG.
0, and a sacrificial layer 90 is formed in a region facing a boundary between a longitudinal end portion of each of the pressure generating chambers 12 and a peripheral wall to be formed in a later step, in a width direction of each pressure generating chamber.
Is patterned so as to remain. The sacrificial layer 90 may be provided for each pressure generating chamber.

Next, as shown in FIG. 3C, the lower electrode film 60 is formed on the elastic plate 50 and the sacrificial layer 90 by sputtering. At this time, the lower electrode film 60 is
Bending portion 6 formed along the surface of 0 and bent in an inverted concave shape
5 are formed. As a material of the lower electrode film 60, platinum or the like is preferable. This is because it is necessary to crystallize a piezoelectric layer 70 described later, which is formed by a sputtering method or a sol-gel method, by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric layer 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and for these reasons, platinum is preferred.

In a later step of removing the sacrificial layer 90,
In order not to adversely affect the lower electrode film 60, the sacrificial layer 90
After forming a protective film such as zirconium oxide (ZrO ₂ ) on the upper and elastic plates 50, it is preferable to form the lower electrode film 60 on the protective film.

Next, as shown in FIG. 3D, a piezoelectric layer 70 is formed on the lower electrode film 60. In this embodiment, a so-called sol-gel method is used, in which a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried and gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. Formed. As a material for the piezoelectric layer 70, a lead zirconate titanate-based material is suitable when used in an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited, and may be, for example, a sputtering method.

Further, after forming a precursor film of lead zirconate titanate by a sol-gel method or a sputtering method,
A method of growing crystals at a low temperature by a high-pressure treatment method in an alkaline aqueous solution may be used.

Next, as shown in FIG. 4A, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In the present embodiment, platinum is formed by sputtering.

Next, as shown in FIG. 4B, the piezoelectric layer 70 and the upper electrode film 80 are etched to
The patterning of 20 and the lead-out part 330 is performed. At this time, since the etching is performed only for the thickness of the upper electrode film 80 and the thickness of the piezoelectric layer 70, as shown in FIG. Then, a part of the sacrifice layer 90 is removed to form an exposed part 90a in which a part of the sacrifice layer 90 is exposed.

Next, as shown in FIG. 4C, the sacrificial layer 9 is formed.
The sacrificial layer 90 is removed from the exposed portion 90a of the space 10 by wet etching or etching with steam, and the space 10 is removed.
0 is formed. In this embodiment, since the sacrifice layer 90 is made of PSG, the sacrifice layer 90 is etched with a hydrofluoric acid aqueous solution. When polysilicon is used, etching can be performed with a mixed aqueous solution of hydrofluoric acid and nitric acid or an aqueous solution of potassium hydroxide. In addition, when etching the sacrificial layer 90, a protective film is formed so as to cover at least the piezoelectric element 300 so as not to affect the piezoelectric element 300, and the protective film is formed in a region of the protective film facing the exposed portion 90a of the sacrificial layer 90. A through hole is provided, and the sacrificial layer 9 is formed through the through hole.
Preferably, 0 is etched. The piezoelectric layer 70
A resist that can be removed with a solvent such as acetone which does not affect the above may be used as the sacrificial layer. In this case, it is not necessary to provide a protective film.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 4D, the silicon single crystal substrate is subjected to anisotropic etching with the above-described alkali solution to form the pressure generating chamber 12 and the like.

As described above, in the present embodiment, even if the drawer 330 is driven, a space is formed between the lower electrode film 60 and the elastic plate 50 at the boundary between the longitudinal end of the pressure generating chamber 12 and the peripheral wall. By providing a certain space portion 100, destruction of the boundary elastic plate 50 and the drawer portion 330 is prevented.

The piezoelectric element 300 of the drawer 330
Since the is formed thin by the space 100, the displacement efficiency of the elastic plate 50 is improved without hindering the displacement of the elastic plate 50. In the present embodiment, the drawer 330 is provided at the longitudinal end of the pressure generating chamber 12. However, the present invention is not limited to this, and the drawer 330 may be located at an arbitrary position in the pressure generating chamber 12 due to wiring. Can be provided. Further, a similar structure may be provided at both ends in the longitudinal direction of the pressure generating chamber 12.

A series of film formation and anisotropic etching of the piezoelectric active section 320 and the pressure generating chamber 12 described above are performed by:
A large number of chips are simultaneously formed on one wafer, and after completion of the process, the wafer is divided into flow path forming substrates 10 each having one chip size as shown in FIG. Further, the divided flow path forming substrate 10 is sequentially adhered and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 to form an ink jet recording head.

The ink jet recording head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown) and fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink. After that, a voltage is applied between the upper electrode film 80 and the lower electrode film 60 in accordance with a recording signal from an external drive circuit (not shown) to cause the elastic plate 50, the lower electrode film 60, and the piezoelectric layer 70 to bend and deform. As a result, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle opening 11.

(Embodiment 2) FIG. 6 is a longitudinal sectional view of a pressure generating chamber of an ink jet recording head according to Embodiment 2. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 6, the lower electrode film 60A is formed over the entire surface of the elastic plate 50,
Is provided between the lower electrode film 60A facing the boundary between the end of the pressure generating chamber 12 and the peripheral wall and the piezoelectric layer 70A.
That is, a groove is provided in the piezoelectric layer 70 </ b> A of the lead portion 330 in the width direction, and the groove is formed in the space 10.
It is 0.

In the method of manufacturing such an ink jet recording head, the lower electrode film 60A is formed on the elastic plate 50,
This is the same as the manufacturing method of the first embodiment described above, except that the sacrificial layer 90 is patterned on the lower electrode film 60A. In this embodiment, the material of the sacrificial layer 90 is, for example, spin-coated with a resist so that the piezoelectric layer 70A and the lower electrode film 60A are not removed in the subsequent step of removing the sacrificial layer 90. In the step of removing the sacrifice layer 90, it was removed by etching with a solvent such as acetone.

In the ink jet recording head having such a configuration, when a voltage is applied to each of the electrode films 60A and 80, the piezoelectric active portion 320 is driven, but the lead portion 33 is driven.
0, the lower electrode film 60A and the piezoelectric layer 70A are
Since it is separated by 0, no voltage is applied and no driving is performed. This can prevent the drawer 330 from being broken.

(Other Embodiments) The embodiments of the present invention have been described above, but the basic configuration of the ink jet recording head is not limited to the above.

For example, in addition to the sealing plate 20 described above, the common ink chamber forming plate 30 may be made of glass ceramic, and the thin wall 41 may be made of glass ceramic as a separate member. Changes are free.

In the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10. However, the nozzle openings may be formed to project in a direction perpendicular to the surface.

FIG. 7 is an exploded perspective view of the embodiment configured as described above, and FIG. 8 is a sectional view of the flow path. In this embodiment, the nozzle opening 11 is formed in the nozzle substrate 120 opposite to the piezoelectric element, and the nozzle communication port 22 for communicating the nozzle opening 11 with the pressure generating chamber 12 is provided in the sealing plate 2.
0, the common ink chamber forming substrate 30, the thin plate 41A, and the ink chamber side plate 40A.

In this embodiment, the thin plate 41
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40A. Is omitted.

Of course, it is needless to say that the respective embodiments described above can achieve further effects by being appropriately combined and implemented.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the gist of the present invention is not contradicted.

The ink jet recording head of each of the embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. FIG.
FIG. 2 is a schematic diagram illustrating an example of the ink jet recording apparatus.

As shown in FIG. 9, the recording head units 1A and 1B having ink jet recording heads are provided with detachable cartridges 2A and 2B constituting ink supply means.
The carriage 3 on which B is mounted is provided movably in the axial direction on a carriage shaft 5 attached to the apparatus main body 4. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, the apparatus main body 4 is provided with a platen 8 along the carriage 3. The platen 8 can be rotated by a driving force of a paper feed motor (not shown), and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller, is wound around the platen 8 and conveyed. It has become so.

[0077]

As described above, according to the present invention,
A space, which is a space, is provided at least in a region facing the boundary between the end portion of the pressure generating chamber between the upper electrode and the elastic plate and the peripheral wall and the peripheral wall of the lead portion. This allows
The drawer has a structure floating from the elastic plate, so that the elastic plate can be prevented from being broken by stress concentration at the drawer. Further, since the piezoelectric layer of the drawer portion is formed to be thinner by the space portion than that of the region facing the pressure generating chamber, the displacement efficiency of the elastic plate is improved without disturbing the displacement of the elastic plate. Further, since the elastic plate is prevented from being broken by the drawer, the drawer can be provided at an arbitrary position.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the inkjet recording head according to the first embodiment of the invention.

FIG. 3 is a cross-sectional view showing a manufacturing process of the ink jet recording head according to Embodiment 1 of the present invention, and is a cross-sectional view of a region facing a pressure generating chamber.

FIG. 4 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to the first embodiment of the present invention, which is a cross-sectional view of a region facing a pressure generating chamber.

FIG. 5 is a cross-sectional view illustrating a step of manufacturing the ink jet recording head according to the first embodiment of the present invention, which is a region of the pressure generating chamber facing the partition.

FIG. 6 is a sectional view of a main part of an ink jet recording head according to a second embodiment of the invention.

FIG. 7 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating an ink jet recording head according to another embodiment of the present invention.

FIG. 9 is a schematic view of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 11 nozzle opening 12 pressure generating chamber 50 elastic plate 51 silicon oxide film 52 zirconium oxide film 60 lower electrode film 61 lower electrode film 65 for wiring 65 bent portion 70 piezoelectric layer 80 upper electrode film 90 sacrifice layer 90a exposed portion Reference Signs List 100 space 300 piezoelectric element 320 piezoelectric active part 330 lead-out part

Claims (12)

[Claims] 1. An ink jet type comprising: a pressure generating chamber communicating with a nozzle opening; and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided in a region corresponding to the pressure generating chamber via an elastic plate. In the recording head, the lower electrode, the piezoelectric layer, and the upper electrode constituting the piezoelectric element have an extending portion extending from an area facing the pressure generating chamber to an area outside the pressure generating chamber. The space between the piezoelectric layer and the elastic plate in a region facing the boundary between the end of the pressure generating chamber and the peripheral wall of the portion, at least the piezoelectric layer and the upper electrode, the An ink jet type recording head extending over a space. 2. The ink jet recording head according to claim 1, wherein the space is formed between the lower electrode and the elastic plate. 3. The ink jet recording head according to claim 2, wherein the lower electrode extending across the space has an inverted concave cross section. 4. The piezoelectric layer according to claim 1, wherein a thickness of a region facing the space portion is smaller than a thickness of a region facing the pressure generating chamber. An ink jet recording head, characterized in that: 5. The piezoelectric element according to claim 1, wherein the piezoelectric element located on the space is provided in a region facing a boundary between an end of the pressure generating chamber and a peripheral wall, and is finally provided. An ink jet recording head comprising a thin film formed on a sacrificial layer to be removed. 6. The ink jet recording head according to claim 1, wherein the thickness of the space is between 0.2 μm and 1.0 μm. 7. The ink jet recording head according to claim 2, wherein a protective film is provided on the space side of the lower electrode. 8. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and a lithography method. An ink jet recording head, comprising: 9. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 10. An elastic plate, a lower electrode, a piezoelectric layer, and an upper electrode are sequentially formed in a region corresponding to the pressure generating chamber of a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is defined. Forming an element and extending the piezoelectric element in a region facing the boundary between an end of the pressure generating chamber and a peripheral wall of an extended portion extending from inside a region facing the pressure generating chamber to outside the region; A method for manufacturing an ink jet recording head, wherein a space is formed between a layer and the elastic plate, and at least the piezoelectric layer and the upper electrode extend over the space. After the elastic plate is formed thereon, a step of patterning a sacrificial layer in a region opposed to a boundary between the end portion of the pressure generating chamber and the peripheral wall while forming the piezoelectric element on the elastic plate, Forming the space by removing the sacrificial layer Method of manufacturing the ink jet recording head is characterized in that a step. 11. The method according to claim 10, wherein the pattern formation of the sacrificial layer is performed before the formation of the lower electrode. 12. The method according to claim 11, wherein a protective film is formed on the elastic plate and the sacrificial layer after patterning the sacrificial layer.