JPH1191104A - Ink-jet type recording head, its manufacture, and ink-jet type recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet type recording head and its manufacturing method wherein an action of a lower electrode as a common electrode is secured enough, and at the same time a shift amount is increased while a compliance is suppressed small, a discharge speed is increased and a driving voltage is decreased. SOLUTION: This ink-jet type recording head has a piezoelectric element 30 including a lower electrode 60, a piezoelectric body layer 70 and an upper electrode 80 on an elastic film 50. The piezoelectric body layer 70 and upper electrode 80 are formed for every area confronting to a pressure generation chamber 12 not to exceed the area confronting to the pressure generation chamber 12. An area part confronting to each pressure generation chamber 12, and a wiring pattern part connecting these area parts and connected to the outside are continuously formed at the lower electrode 60. The part confronting to the pressure generation chamber 12 where a piezoelectric element 300 is not formed is removed except at least a part thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a part of a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate. The present invention relates to an ink jet recording head for ejecting ink droplets by displacement, 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 communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass through the nozzle opening. An ink jet recording head for ejecting ink droplets uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and a flexural vibration mode piezoelectric actuator.
The types have been put to practical use.

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 the diaphragm, 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 a diaphragm by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of a 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 over the entire surface of the diaphragm by a film forming technique 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.

[0006] According to this, the operation of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only can the piezoelectric element be manufactured by a precise and simple method such as 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. In this case, the piezoelectric actuator corresponding to each pressure generating chamber can be driven by providing at least the upper electrode only for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the vibration plate. Due to the problem of the amount of displacement per unit drive voltage and the stress applied to the piezoelectric layer at the part facing the pressure generating chamber and the part that crosses the outside, the piezoelectric active part consisting of the piezoelectric layer and the upper electrode is located outside the pressure generating chamber. It is desirable to form so as not to come out.

[0007]

In general, the piezoelectric constant of a piezoelectric thin film is only one-half to one-third that of a thick thin film, so that it is difficult to obtain an effective ink discharge amount. is there.

Therefore, in order to increase the amount of displacement caused by driving the piezoelectric actuator, it is desirable to increase the compliance by reducing the thickness of the lower electrode acting as a vibration plate. There's a problem.

In view of such circumstances, the present invention increases the amount of displacement while suppressing the compliance while sufficiently ensuring the function of the lower electrode as the common electrode, and increases the discharge speed.
An object of the present invention is to provide an ink jet recording head, a method of manufacturing the same, and an ink jet recording apparatus capable of reducing the driving voltage.

[0010]

According to a first aspect of the present invention for solving the above-mentioned problems, an elastic film forming a part of a pressure generating chamber communicating with a nozzle opening and a region corresponding to the pressure generating chamber are provided. In an ink jet recording head provided on the elastic film and including a lower electrode, a piezoelectric layer, and a piezoelectric element including an upper electrode, the piezoelectric layer and the upper electrode forming the piezoelectric element may include the pressure generation. The lower electrode is formed for each region facing the chamber and without extending outside the region facing the pressure generation chamber, and the lower electrode connects the portion of the region facing each pressure generation chamber and the portion of these regions to each other. A wiring pattern portion connected to the outside is continuously formed, and at least a part of the portion facing the pressure generating chamber where the piezoelectric layer constituting the piezoelectric element is not formed is removed except for at least a part. In an ink jet recording head, characterized by that.

In the first aspect, the pattern of the piezoelectric layer and the upper electrode constituting the piezoelectric element facing the pressure generating chamber does not extend outside the region facing the pressure generating chamber, and the lower electrode is Since at least a part of the region facing the edge of the pressure generating chamber is removed, the stress due to the driving of the piezoelectric element is suppressed to a small value, and the displacement is greatly improved.

According to a second aspect of the present invention, in the first aspect, the lower electrode is at least a longitudinal portion of a portion facing the pressure generating chamber where the piezoelectric layer constituting the piezoelectric element is not formed. An ink jet recording head is characterized in that portions other than one end in the direction are removed.

In the second aspect, the stress due to the driving of the piezoelectric element is suppressed to a small value, and breakage of the longitudinal end can be prevented.

According to a third aspect of the present invention, in the first or second aspect, the pressure generation chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by a thin film and a lithography method. An ink jet recording head is characterized in that:

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

According to a fourth aspect of the present invention, in any one of the first to third aspects, an insulator layer is formed on an upper surface of the upper electrode, and a lead electrode and the upper electrode are formed on the insulator layer. An ink jet type recording head having a contact hole portion which is a window for forming the contact portion.

In the fourth aspect, each piezoelectric element and the lead electrode are connected via the contact hole.

According to a fifth aspect of the present invention, there is provided an ink jet recording apparatus comprising any one of the first to fourth ink jet recording heads.

According to the fifth aspect, it is possible to realize an ink jet recording apparatus in which the driving efficiency of the head is improved and the ink can be ejected favorably.

According to a fifth aspect of the present invention, there is provided a first step of sequentially forming a silicon dioxide film, a lower electrode, a piezoelectric layer and an upper electrode on a silicon substrate in this order; A second step of simultaneously patterning the upper electrode to form an entire wiring pattern of the lower electrode, and patterning the piezoelectric layer and the upper electrode to form a piezoelectric element in a region facing each pressure generating chamber. A third step of forming, and a wiring pattern outside a region of the portion where the piezoelectric layer constituting the piezoelectric element is not formed in a region facing the pressure generating chambers by patterning the lower electrode. And a fourth step of removing a portion other than the portion that is continuous with the portion.

According to the fifth aspect, the entire pattern of the lower electrode formed on the silicon dioxide film, the piezoelectric element formed in the region facing the pressure generating chamber, and the lower electrode surrounding the piezoelectric element are formed. Since the removed portion is formed by removing a portion other than the continuous portion with the entire pattern, the stress due to the driving of the piezoelectric element is suppressed to a small value, and the displacement is greatly improved.

According to a sixth aspect of the present invention, in the fifth aspect, the lower electrode removed in the fourth step is a portion on both sides in the width direction of the pressure generating chamber. A method for manufacturing a recording head.

According to the sixth aspect, since the lower electrode is removed from the portion corresponding to the arms on both sides of the piezoelectric layer constituting the piezoelectric element, the displacement can be increased while keeping the compliance small.

[0024]

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

(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 shows a cross-sectional structure in a longitudinal direction of one of the pressure generating chambers. FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal 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.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with a 1-2 μm thick elastic film 50 of silicon dioxide formed by thermal oxidation in advance.

On the other hand, a silicon single crystal substrate is anisotropically etched on the opening surface of the flow path forming 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 KOH, the substrate is gradually eroded and the first (111) plane perpendicular to the (110) plane is formed. A second (1) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
11) plane, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
This is performed using the property of being 80.
By such anisotropic etching, two first (11
Precision processing can be performed based on depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

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 film 50 almost through 0. The amount of the elastic film 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 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.

Further, each pressure generating chamber 12 and a common ink chamber 31 described later are connected to each pressure generating chamber 1 of the sealing plate 20 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 and has a thickness of, for example, 0.1 to 1 mm and a coefficient of linear expansion of 300 ° C. or less. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. 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. In addition, the sealing plate 20
The other surface constitutes 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 in accordance with 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, the thickness of the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10 is, for example, about 0.5 μm.
A lower electrode film 60, a piezoelectric film 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 formed by lamination in a process to be described later.
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 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 used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Here, the piezoelectric element 300 and a vibration plate that generates displacement by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

In this embodiment, as will be described in detail later,
The piezoelectric film 70 and the upper electrode film 80 are formed for each pressure generating chamber 12, and the lower electrode film 60, which is the arm portion of the piezoelectric actuator on both sides in the width direction of the pressure generating chamber 12, is removed to increase the displacement. I have. Also, each pressure generating chamber 1 of the lower electrode film 60
The connection between the portion corresponding to No. 2 and the entire pattern is made at both ends in the longitudinal direction of the pressure generating chamber 12.

Here, a process of forming the piezoelectric film 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.

As shown in FIG. 4A, first, a silicon single crystal substrate wafer serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, a lower electrode film 60 is formed by sputtering. Pt or the like is preferable as the material of the lower electrode film 60. This is because a piezoelectric film 70 described later, which is formed by a sputtering method or a sol-gel method,
After film formation, 600 to 10 in an air atmosphere or an oxygen atmosphere
This is because it is necessary to perform crystallization by firing at a temperature of about 00 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used for the piezoelectric film 70, the conductivity of the material by diffusion of PbO is increased. It is desirable that there is little change in sex, and Pt is preferred for these reasons.

Next, as shown in FIG. 4C, a piezoelectric film 70 is formed. The piezoelectric film 70 can be formed by a sputtering method, but in the present embodiment, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried, gelled, and further baked at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of a metal oxide is used. As a material for the piezoelectric film 70, a lead zirconate titanate (PZT) -based material is suitable when used in an ink jet recording head.

Next, as shown in FIG. 4D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and many metals such as Al, Au, Ni, and Pt, and a conductive oxide can be used. In the present embodiment, P
t is formed by sputtering.

Next, as shown in FIG. 5, the lower electrode film 60,
The piezoelectric film 70 and the upper electrode film 80 are patterned.

First, after forming a resist pattern 210 as shown in FIG. 5A, the lower electrode film 60 and the piezoelectric film 7 are formed.
0 and the upper electrode film 80 are etched together, and FIG.
As shown in (1), the entire pattern of the lower electrode film 60 is patterned.

Here, the resist pattern 210 is formed, for example, by applying a negative resist HR-100 (manufactured by Fuji Hunt) by spin coating or the like, and performing exposure, development, and baking using a mask having a predetermined shape. . Of course, a positive resist may be used instead of the negative resist.

The etching is performed using a dry etching apparatus, for example, an ion milling apparatus until the elastic film 50 is exposed. In addition, the resist pattern 210
It is removed using an ashing device or the like.

As the dry etching method, a reactive etching method or the like may be used other than the ion milling method.
It is also possible to use wet etching instead of dry etching, but it is preferable to use dry etching because patterning accuracy is somewhat inferior to dry etching and the material of the upper electrode film 80 is limited. .

Next, as shown in FIG. 5C, the resist pattern 220 is used to cover the portion of the lower electrode other than the entire pattern where the elastic film 50 is exposed and the region facing the pressure generating chamber 12. Then, only the piezoelectric film 70 and the upper electrode film 80 are etched, and as shown in FIG. Cut off. Note that the formation and etching of the resist pattern 220 can be performed in the same manner as in the above-described steps.

Here, the piezoelectric film 70 and the upper electrode film 80 other than the piezoelectric active portion 320 are basically removed, but the portion other than the entire pattern of the lower electrode film 60 is made of silicon dioxide. Since the elastic film 50 is exposed,
Similarly, in order to protect this portion from etching, the resist pattern 220 is formed so as to cover the outer peripheral portion of the entire pattern of the lower electrode film 60. Therefore, as shown in FIG. 6, the narrow band portion 34 composed of the piezoelectric film 70 and the upper electrode film 80 is provided on the outer peripheral edge of the entire lower electrode film pattern 330.
0 is formed.

Next, as shown in FIG. 5 (e), each pressure generating chamber 12 (in FIG. 5, the pressure generating chamber 12 has not been formed yet,
As shown in FIG. 5F, a lower electrode is used as shown in FIG. By patterning the film 60, a lower electrode film removal part 350 is formed. By providing the lower electrode film removing section 350 in this manner, the amount of displacement due to voltage application to the piezoelectric active section 320 is improved.

As described above, first, the lower electrode film 60
Is formed, the piezoelectric active portion 320 is patterned, and finally, the lower electrode film removing portion 35 is formed.
By patterning 0, the patterning is completed.

After patterning the lower electrode film 60 and the like as described above, preferably, at least the periphery of the upper surface of each upper electrode film 80, the side surface of the piezoelectric film 70, and the lower electrode film 6
Insulator layer 90 having electrical insulation so as to cover the side surface
Is formed (see FIG. 1). Here, the insulator layer 90 is made of a material that can be formed by a film forming method or shaped by etching, for example, silicon oxide, silicon nitride, an organic material, preferably a photosensitive polyimide having low rigidity and excellent electrical insulation. It is preferred to form with.

Then, each piezoelectric active portion 3 of the insulator layer 90
A contact hole 90 a that exposes a part of the upper electrode film 80 for connecting to the lead electrode 100 is formed in a part of the part that covers the upper surface of the part corresponding to one end of the 20. One end is connected to each upper electrode film 80 via the contact hole 90a, and the other end is formed with a lead electrode 100 extending to the connection terminal portion. Lead electrode 1
The reference numeral 00 is formed so as to have a width as narrow as possible so as to reliably supply a drive signal to the upper electrode film 80.

FIG. 7 shows a process of forming such an insulator layer.
Shown in

First, as shown in FIG. 7A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80 and the side surface of the piezoelectric film 70. Suitable materials for the insulator layer 90 are as described above, but in the present embodiment, a negative photosensitive polyimide is used.

Next, as shown in FIG. 7B, by patterning the insulator layer 90, each of the pressure generating chambers 12 is formed.
A contact hole 90a is formed in a portion corresponding to the vicinity of the end on the ink supply side. This contact hole 90a
Is for connecting the lead electrode 100 and the upper electrode film 80. The contact hole 90a may be provided in another part of the pressure generating chamber 12, for example, in a central part or an end on the nozzle side.

Next, for example, a lead electrode 100 is formed by depositing a conductor such as Cr-Au on the entire surface and then patterning it.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 7C, 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. In addition,
In the series of film formation and anisotropic etching described above, a number of chips are simultaneously formed on one wafer, and after completion of the process, each of the flow path forming substrates 10 having one chip size as shown in FIG. To divide. 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 head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown), fills the inside from the common ink chamber 31 to the nozzle opening 11 with ink, and
In accordance with a recording signal from an external drive circuit (not shown), a voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100, and the elastic film 50, the lower electrode film 60, and the piezoelectric film 70 The pressure generating chamber 1 is deformed by bending.
The pressure in 2 increases, and ink droplets are ejected from nozzle opening 11.

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

For example, in addition to the above-described sealing plate 20, the common ink chamber forming plate 30 may be made of glass ceramic, and the thin film 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. 8 is an exploded perspective view of the embodiment configured as described above, and FIG. 9 is a cross-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 plate 30, the thin plate 41A, and the ink chamber side plate 40A are arranged so as to penetrate therethrough.

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 40. Is omitted.

In each of the embodiments described above, a thin-film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a piezoelectric film is formed by laminating substrates to form a pressure generating chamber, or a piezoelectric film is formed by attaching a green sheet or by screen printing, or a piezoelectric film formed by crystal growth. The present invention can be applied to ink jet recording heads having various structures, such as those that form a recording medium.

Further, in the above-described embodiment, the example in which the insulator layer is provided between the piezoelectric element and the lead electrode has been described.
The present invention is not limited to this. For example, without providing an insulator layer, an anisotropic conductive film is thermally welded to each upper electrode, and this anisotropic conductive film is connected to a lead electrode. The connection may be made using various bonding techniques.

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. 1 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 10, recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B constituting ink supply means are provided detachably, and a carriage 3 on which the recording head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. I have. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

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 shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is wound around the platen 8. It is designed to be transported.

[0072]

As described above, in the present invention,
The piezoelectric element is formed so as not to extend beyond the region facing the pressure generating chamber, and the lower electrode film other than the portion facing the piezoelectric element facing the pressure generating chamber is removed to the maximum, so that the amount of deformation is maximized. However, there is an effect that there is no fear of destruction of the piezoelectric film and the like.

[Brief description of the drawings]

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

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the same.

FIG. 3 is a view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a plan view showing a main part of the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a process of forming an insulator layer and a pressure generating chamber according to the first embodiment of the present invention.

FIG. 8 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating an ink jet recording head according to another embodiment of the present invention.

FIG. 10 is a perspective view schematically showing an ink jet recording apparatus according to one 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 film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 90 insulating layer 90a contact hole 100 lead electrode 300 piezoelectric element 310 piezoelectric active portion 350 lower electrode film removal Department

Claims (7)

[Claims] 1. An elastic film forming a part of a pressure generating chamber communicating with a nozzle opening, and a lower electrode, a piezoelectric layer, and an upper electrode provided on the elastic film in a region corresponding to the pressure generating chamber. In an ink jet recording head comprising a piezoelectric element, the piezoelectric layer and the upper electrode constituting the piezoelectric element are arranged in each region facing the pressure generation chamber and outside the region facing the pressure generation chamber. The lower electrode is formed in such a manner that a portion of a region facing each of the pressure generating chambers and a wiring pattern portion connecting these portions to each other and connecting to the outside are formed continuously, and An ink jet recording head, wherein at least a part of the portion facing the generation chamber where the piezoelectric layer constituting the piezoelectric element is not formed is removed except at least a part thereof. 2. The device according to claim 1, wherein the lower electrode is removed at a portion facing the pressure generating chamber except at least one longitudinal end of a portion where the piezoelectric layer constituting the piezoelectric element is not formed. An ink jet recording head. 3. 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 a thin film and a lithography method. Inkjet recording head. 4. The method according to claim 1, wherein an insulator layer is formed on an upper surface of the upper electrode, and the insulator layer has a portion for forming a contact portion between the lead electrode and the upper electrode. An ink jet recording head having a contact hole portion serving as a window. 5. An ink jet recording apparatus comprising the ink jet recording head according to claim 1. 6. A first method for sequentially forming a silicon dioxide film, a lower electrode, a piezoelectric layer and an upper electrode on a silicon substrate in this order.
And a second step of simultaneously patterning the lower electrode, the piezoelectric layer and the upper electrode to form an entire wiring pattern of the lower electrode, and patterning the piezoelectric layer and the upper electrode. A third step of forming a piezoelectric element in a region facing each pressure generating chamber, and the piezoelectric layer forming the piezoelectric element in a region facing each of the pressure generating chambers by patterning the lower electrode. And a fourth step of removing a portion other than a portion continuous with the wiring pattern portion outside the region among the portions not formed, the method comprising the steps of: 7. The method according to claim 5, wherein the lower electrode removed in the fourth step is located on both sides in the width direction of the pressure generating chamber.