JPH11314365A - Ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a displacing efficiency of a diaphragm by improving a hardness and characteristics of a lower electrode. SOLUTION: In the ink jet recording head comprising an elastic film for constituting a part of a pressure generating chamber 12 communicating with a nozzle opening, a lower electrode 60 provided on the film, a piezoelectric unit layer 70 formed on a surface of the layer 70, and an upper electrode 80 formed on a surface of the layer 70 in such a manner that a piezoelectric active unit is formed in an area opposed to the chamber 12; the electrode 60 is formed of at least one type selected from the group consisting of Pt, Ir, Ni, Fe and Co, and doped with at least one type selected from the group consisting of N, C and P so that the lower electrode becomes hard.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element in which a part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is formed of an elastic plate, and a piezoelectric layer is formed on the surface of the elastic plate. The present invention relates to an ink jet recording head and an ink jet recording apparatus that eject ink droplets by displacement of a layer.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is formed of an elastic film, and this elastic film is deformed by a piezoelectric vibrator to pressurize ink in the pressure generating chamber to open the nozzle opening. There are two types of ink-jet recording heads that eject ink droplets from a piezoelectric vibrator, one that uses a piezoelectric vibrator that expands and contracts in the axial direction of the piezoelectric vibrator, and one that uses a piezoelectric vibrator that flexes. Has 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 vibrator into contact with an elastic film, so that a head suitable for high-density printing can be manufactured. A complicated process of cutting the piezoelectric vibrators into a comb-tooth shape in accordance with the arrangement pitch of the nozzle openings, and a work of positioning and fixing the separated piezoelectric vibrators in the pressure generating chambers, which complicates the manufacturing process. There is.

On the other hand, in the latter, a piezoelectric vibrator can be formed on an elastic film 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. However, due to the use of flexural vibration, a certain area is required, and there is a problem 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 elastic film by a film forming technique as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which this piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by lithography, and a piezoelectric vibrator is formed so as to be independent for each pressure generating chamber.

According to this, the work of attaching the piezoelectric vibrator to the elastic film becomes unnecessary, and the precision of the lithography method is eliminated.
In addition to the fact that the piezoelectric vibrator can be manufactured by a simple and simple method, there is an advantage that the thickness of the piezoelectric vibrator can be reduced and high-speed driving is possible. In this case, the piezoelectric vibrator corresponding to each pressure generating chamber can be driven by providing at least only the upper electrode for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the elastic film.

[0007]

However, in the above-described manufacturing method using the thin film technology and the lithography method,
A pressure generating chamber is formed after patterning of the thin film. At this time, the lower electrode constituting a part of the diaphragm is soft because it is formed of a metal such as platinum (Pt), and the initial deflection amount of the diaphragm There is a problem that becomes large. Further, when ink is ejected by driving the piezoelectric vibrator, there is a problem that the amount of deformation of the diaphragm is small and a sufficient excluded volume cannot be obtained. Further, the mechanical fatigue of the lower electrode increases due to the film stress, so that there is a problem that the life is relatively short.

In view of such circumstances, it is an object of the present invention to provide an ink jet recording head and an ink jet recording apparatus which improve the hardness and characteristics of the lower electrode and improve the displacement efficiency of the diaphragm. .

[0009]

According to a first aspect of the present invention for solving the above-mentioned problems, an elastic film constituting a part of a pressure generating chamber communicating with a nozzle opening and a lower member provided on the elastic film are provided. An ink-jet type comprising an electrode, a piezoelectric layer formed on the lower electrode, and an upper electrode formed on the surface of the piezoelectric layer, wherein a piezoelectric active portion is formed in a region facing the pressure generating chamber. In the recording head, the lower electrode is composed of Pt, Ir, N
An ink jet recording head formed of at least one selected from the group consisting of i, Fe, and Co, and doped with at least one selected from the group consisting of N, C, and P.

[0010] In the first aspect, the mechanical characteristics of the lower electrode are improved, and the initial deflection of the diaphragm including the elastic film and the lower electrode is reduced.

According to a second aspect of the present invention, in the first aspect, the lower electrode is formed by doping Pt with at least one selected from the group consisting of N, C and P. In the ink jet recording head.

In the second aspect, the mechanical characteristics of the lower electrode are more reliably improved, and the initial deflection of the diaphragm comprising the elastic film and the lower electrode is reduced.

According to a third aspect of the present invention, in the first or second aspect, at least one doping amount of the lower electrode selected from the group consisting of N, C and P is 0.08 to
0.2% by weight.

In the third aspect, the doping amount is 0.0
When the content is 8 to 0.2% by weight, the mechanical properties of the lower electrode are improved.

According to a fourth aspect of the present invention, in any one of the first to third aspects, a lead electrode for applying a voltage to the piezoelectric active portion and the upper electrode are provided on an upper surface of the piezoelectric active portion. An ink jet recording head having a contact portion for making a connection with the ink jet recording head.

In the fourth aspect, a voltage is applied to the piezoelectric active section via the contact section.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the piezoelectric layer and the upper electrode constituting the piezoelectric active portion are at least arranged in a longitudinal direction of the pressure generating chamber. An ink jet recording head is provided which extends from one end to the peripheral wall.

In the fifth aspect, a voltage is applied to the piezoelectric active section via the upper electrode on the peripheral wall.

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

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

According to a seventh 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 sixth aspects.

According to the seventh aspect, it is possible to realize an ink jet recording apparatus in which the ink ejection performance of the head is improved.

[0023]

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

As shown in the figure, the flow path forming substrate 10 is formed of 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 an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the 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 and the first (111) plane 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 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.]. 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 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 one surface thereof constitutes 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 film 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 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. (Piezoelectric element) 300 is constituted. Here, the piezoelectric vibrator 300 includes the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 8.
Refers to the portion containing 0. Generally, one of the electrodes of the piezoelectric vibrator 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each of the pressure generating chambers 12. In this case, the piezoelectric active layer 32 is constituted by one of the patterned electrodes and the piezoelectric film 70, and a portion where the piezoelectric strain is generated by applying a voltage to both electrodes is formed.
It is called 0. In the present embodiment, the lower electrode film 60 is a common electrode of the piezoelectric vibrator 300, and the upper electrode film 80 is the piezoelectric vibrator 30.
Although the number of the individual electrodes is 0, 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. In the example described above, the elastic film 50 and the lower electrode film 6
Although 0 functions as a diaphragm, the lower electrode film may also serve as an elastic film.

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 FIG.

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. As will be described in detail later, in the present embodiment, the lower electrode film 60 is doped with a non-metallic material to improve the mechanical characteristics. Examples of the material of the lower electrode film 60 include Ir, Ni, Fe, Co,
Pt or the like can be used, but Pt is preferred. This is because the piezoelectric film 70 described below, which is formed by sputtering or a sol-gel method, needs to be crystallized by baking at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. It is. 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 sputtering, but in this embodiment, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried and gelled, and further baked at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of an 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, as shown in FIG. 5A, the lower electrode film 60, the piezoelectric film 70 and the upper electrode film 80 are etched together to pattern the entire pattern of the lower electrode film 60. Next, as shown in FIG. 5B, only the piezoelectric film 70 and the upper electrode film 80 are etched to form the pressure generating chamber 12.
The patterning of the piezoelectric body active portion 320 is performed only in the region opposed to.

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

A part of the upper surface of the insulator layer 90 corresponding to one end of each upper electrode film 80 covers a part of the upper electrode film 80 for connection to a lead electrode 100 described later. A contact hole 90a exposing a portion is formed. Then, this contact hole 90a
A lead electrode 100 having one end connected to each upper electrode film 80 and the other end extending to the connection terminal portion is formed.
The lead electrode 100 is formed so as to be as narrow as possible so as to reliably supply a drive signal to the upper electrode film 80.

FIG. 6 shows a process of forming such an insulator layer.
Shown in

First, as shown in FIG. 6A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80 and the side surfaces of the piezoelectric film 70 and the lower electrode film 60. This insulator layer 9
The preferred material of 0 is as described above, but in this embodiment, a negative photosensitive polyimide is used.

Next, as shown in FIG. 6B, by patterning the insulator layer 90, the upper electrode film 80 is brought into contact with the portion corresponding to the vicinity of the end on the ink supply side of the pressure generating chamber 12 on the ink supply side. A hole 90a is formed.

The contact hole 90a may be provided at a portion corresponding to the piezoelectric active portion 320 of the pressure generating chamber 12, and may be provided at, for example, a central portion or an end on the nozzle side. In this embodiment, the piezoelectric vibrator is connected to the pressure generating chamber 1.
2, the piezoelectric film and the upper electrode film may be extended to a region facing the peripheral wall of the pressure generating chamber 12, for example.

Next, for example, a conductor such as Cr-Au is formed on the entire surface and then patterned to form the lead electrode 100 and the like.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 6C, 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.

Further, in the present embodiment, as described above, the lower electrode film 60 acting as a diaphragm is doped with a predetermined nonmetallic atom to be hardened, so that the characteristics of the lower electrode film 60, for example, breakdown Mechanical properties such as strength, spreadability, and fatigue resistance can be improved.

As a material of the lower electrode film 60, Pt is preferably used for the above-described reason.
Even with Ni, Fe, Co, etc., equivalent mechanical characteristics can be obtained. In addition, as the nonmetallic element to be doped,
It is preferable that the element has relatively low reactivity with a metal, and for example, nitrogen (N), carbon (C), phosphorus (P), or the like is preferable. These non-metallic elements may be doped alone or in combination, but the total doping amount is
Preferably, it is in the range of 0.08 to 0.2 wt%.
If the amount of the non-metallic element is less than 0.08 wt%, a remarkable effect cannot be obtained. On the other hand, if the amount is more than 0.2 wt%, mechanical properties may be changed due to, for example, compound formation. Both are not preferred. Therefore, in the present embodiment, platinum (Pt) is used as the material of the lower electrode film 60, and phosphorus (P) is used as the nonmetal element to be doped at 0.15 wt%.

As a method of forming the lower electrode film doped with a nonmetallic element, for example, phosphorus (P) is added to platinum (Pt) in the step of forming the lower electrode film 60 shown in FIG. The lower electrode film 60 may be formed by sputtering using a target added in advance. Thus, the lower electrode film 60 in which Pt is doped with phosphorus (P) can be formed. The method for forming the lower electrode film doped with the non-metallic element is not limited to the above-described method, and the lower electrode film can be similarly formed by, for example, vacuum evaporation such as electron beam evaporation. For example, in the case of using nitrogen (N) or the like, it can be formed by forming platinum (Pt) by sputtering in a nitrogen atmosphere.

The yield strength, spreadability, and fatigue resistance of the lower electrode film 60 of the present embodiment thus formed and the lower electrode film formed only of platinum (Pt) were measured. The results are shown in Table 1 below. was gotten.

[0056]

[Table 1]

As is clear from Table 1, the lower electrode film 60
Is obtained by adding phosphorus (P) to platinum (Pt).
All of the properties such as yield strength, spreadability, and fatigue resistance are improved. Therefore, by using such a lower electrode film 60 as a part of the diaphragm, the characteristics as the diaphragm are also improved.

FIGS. 7A and 7B are diagrams illustrating the initial deformation when the lower electrode film 60 to which the non-metal element is added is used for the diaphragm. FIG. 7A shows the lower electrode film doped with the non-metal element. It is a figure in the case of film 60, and (b) is a figure in the case of lower electrode film 60A which does not dope a nonmetallic element.

Lower electrode film 60A not doped with a non-metallic element
In this case, as shown in FIG. 7B, the lower electrode film 60A
Is very soft, so that the initial deflection of the diaphragm is very large. On the other hand, in the case of the lower electrode film 60 doped with a non-metal element, the lower electrode film 6
0, the initial deflection amount as the diaphragm is relatively small as shown in FIG. 7A. For example, the initial deflection amount is about half as compared with the case of the lower electrode film 60A not doped with a non-metallic element. The amount of bending can be suppressed.

As described above, the mechanical properties of the lower electrode film can be improved by doping the lower electrode film with a non-metallic element to harden the lower electrode film. Therefore, when forming the pressure generating chamber, the initial deflection amount of the diaphragm can be reduced. Further, with the reduction of the initial bending amount, the amount of deformation of the vibration plate due to the driving of the piezoelectric vibrator is increased, the excluded volume can be increased, and stable ink ejection can be realized.

(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 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.

Further, in the above-described embodiment, the nozzle opening is formed on the end face of the flow path forming substrate 10, but a nozzle opening projecting in a direction perpendicular to the surface may be formed.

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 vibrator, and the nozzle communication port 22 that connects the nozzle opening 11 and the pressure generating chamber 12 is formed with the sealing plate 20 and the common ink. It is arranged so as to penetrate the chamber forming plate 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 40. Is omitted.

Here, also in this embodiment, as in the above-described embodiment, the mechanical characteristics can be improved by adding a non-metallic element to the lower electrode film, and the displacement efficiency as a diaphragm can be improved. Can be improved.

Further, the example in which the insulator layer is provided between the piezoelectric vibrator and the lead electrode has been described. However, the present invention is not limited to this. The conductive film may be thermally welded, and the anisotropic conductive film may be connected to the lead electrode, or may be connected using various bonding techniques such as wire bonding.

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, according to the present invention, the lower electrode film is hardened by doping the lower electrode film with a nonmetallic element, and the mechanical characteristics of the lower electrode film can be improved. Therefore, the amount of initial deflection of the diaphragm when forming the pressure generating chamber can be reduced. Further, with the reduction of the initial deflection amount of the diaphragm, the amount of deformation of the diaphragm due to the driving of the piezoelectric vibrator is improved, and the excluded volume can be increased. The effect that durability can be improved is produced.

[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 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 view showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an initial deflection amount of a diaphragm.

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 schematic diagram 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 film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 90 insulating layer 90a contact hole 100 lead electrode 300 piezoelectric vibrator 320 piezoelectric active part

Claims (7)

[Claims] An elastic film forming a part of a pressure generating chamber communicating with a nozzle opening; a lower electrode provided on the elastic film; a piezoelectric layer formed on the lower electrode; An ink jet recording head comprising: an upper electrode formed on the surface of a body layer; and a piezoelectric active portion formed in a region facing the pressure generating chamber, wherein the lower electrode comprises Pt, Ir, Ni, Fe, and Co. An ink jet recording head formed of at least one selected from the group consisting of: and doped with at least one selected from the group consisting of N, C, and P. 2. The method according to claim 1, wherein the lower electrode comprises Pt.
Wherein at least one selected from the group consisting of N, C and P is doped. 3. The method according to claim 1, wherein at least one doping amount of the lower electrode selected from the group consisting of N, C and P is 0.08 to 0.2% by weight. Inkjet recording head. 4. A contact part for connecting a lead electrode for applying a voltage to said piezoelectric active part and said upper electrode on an upper surface of said piezoelectric active part according to claim 1. An ink jet recording head comprising: 5. The piezoelectric device according to claim 1, wherein the piezoelectric layer and the upper electrode constituting the piezoelectric active part are:
An ink jet recording head extending from at least one end in the longitudinal direction of the pressure generating chamber to a peripheral wall thereof. 6. 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 vibrator is formed by film formation and lithography. An ink jet recording head, characterized in that: 7. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.