JP2011142152A - Method of preserving composition for formation of ceramic thin film, method of forming ceramic thin film, method of manufacturing piezoelectric element, and method of manufacturing liquid injection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of preserving a composition for the formation of a ceramic thin film whose storage stability can be kept favorable over a long period of time, a method of forming the ceramic thin film, a method of manufacturing a piezoelectric element, and a method of manufacturing a liquid injection head. <P>SOLUTION: At least an organometallic compound forming a ceramic thin film and water are admixed to form a composition for the formation of the ceramic thin film. After being cold-crystallized, the composition for the formation of the ceramic thin film is preserved at a temperature higher than a ceiling temperature of a peak region of cold crystallization and lower than a temperature at which melting starts. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for storing a composition for forming a ceramic thin film for producing a ceramic thin film by a chemical solution method, a method for manufacturing a ceramic thin film using the composition, a method for manufacturing a piezoelectric element, and a method for manufacturing a liquid jet head. .

Piezoelectric ceramic thin films represented by lead zirconate titanate (PZT), etc., have spontaneous polarization,
Since it has a high dielectric constant, an electro-optic effect, a piezoelectric effect, a pyroelectric effect, etc., it is applied to a wide range of device development such as piezoelectric elements. In addition, as a method for forming such a piezoelectric ceramic thin film, for example, a MOD method, a sol-gel method, a CVD (Chemical Vapor Deposition) method,
Sputtering methods and the like are known. In particular, chemical solution methods such as the MOD method and the sol-gel method have an advantage that a piezoelectric ceramic thin film can be easily formed at a relatively low cost.

When a piezoelectric ceramic thin film is formed by the MOD method, generally, a colloidal solution obtained by dissolving an organometallic compound such as a metal alkoxide in alcohol and adding a hydrolysis inhibitor or the like to the target is placed on the object. After coating, the film is dried and fired to form a film. on the other hand,
In the case of forming a film by the sol-gel method, a colloidal solution obtained by dissolving an organometallic compound in alcohol, adding a minimum amount of water to the organometallic compound solution, and performing hydrolysis and polycondensation is used. A piezoelectric ceramic thin film is formed in the same manner as in the MOD method (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 06-5946

However, the piezoelectric ceramic thin film forming composition used when forming a piezoelectric ceramic thin film by such a chemical solution method such as the MOD method and the sol-gel method has a problem that the storage stability is poor. For example, when stored for a long period of time, the viscosity decreases, and the film thickness cannot be controlled when the piezoelectric ceramic thin film is formed. Further, when stored for a long time, the sol may aggregate and precipitate. When the sol agglomerates and precipitates, the composition of the piezoelectric ceramic thin film forming composition fluctuates, and this causes the film components of the piezoelectric ceramic thin film to be dispersed unevenly, resulting in the piezoelectric element having the piezoelectric ceramic thin film. Piezoelectric characteristics will fluctuate. Further, in a liquid ejecting head that includes a piezoelectric element as an actuator device, such a variation in piezoelectric characteristics of the piezoelectric element causes variations in liquid ejection characteristics.

In addition, the problem mentioned above is not limited to the composition for piezoelectric ceramic thin film formation, It exists similarly in the composition for other ceramic thin film formation.

In view of such circumstances, the present invention provides a method for storing a composition for forming a ceramic thin film capable of maintaining storage stability well over a long period of time, a method for manufacturing a ceramic thin film using the composition, and a method for manufacturing a piezoelectric element. It is an object to provide a method and a method for manufacturing a liquid jet head.

An aspect of the present invention that solves the above problems includes an organometallic compound constituting a ceramic thin film,
Water is mixed at least to form a ceramic thin film-forming composition, and after cold crystallization of the ceramic thin film forming composition, it is stored at a temperature higher than the upper limit temperature of the cold crystallization peak region and lower than the melting start temperature. And a method for preserving the composition for forming a ceramic thin film.

In such an aspect, the storage stability of the composition for forming a ceramic thin film can be satisfactorily maintained over a long period of time.

As a preferred embodiment of the present invention, the ceramic thin film forming composition includes a piezoelectric ceramic thin film forming composition.

The composition for forming a piezoelectric ceramic thin film preferably contains at least lead, titanium, and zirconium. According to this, a ceramic thin film having excellent piezoelectric characteristics can be formed.

As a preferred embodiment of the present invention, the ceramic thin film forming composition includes at least one of alcohol and carboxylic acid.

Further, the viscosity of the composition for forming a ceramic thin film after storage is 7.0 mPa · s or more and 25.25.
It is preferably 0 mPa · s or less. According to this, the ceramic thin film forming composition can form a ceramic thin film having a uniform film thickness.

According to another aspect of the present invention, a composition for forming a ceramic thin film is prepared by mixing at least an organometallic compound constituting a ceramic thin film and water, and the composition for forming a ceramic thin film is cooled and crystallized. A step of storing at a temperature higher than the upper limit temperature of the crystallization peak region and lower than a melting start temperature, a step of applying a ceramic thin film forming composition stored on one side of the substrate, and baking to form a ceramic thin film; And a ceramic thin film manufacturing method characterized by comprising:

In such an embodiment, a ceramic thin film having uniform characteristics in the film can be formed regardless of the storage period. Moreover, it becomes a manufacturing method of the ceramic thin film with no dispersion | variation in a characteristic for every product.

Another aspect of the present invention is a piezoelectric device comprising: a first electrode provided on a substrate; a piezoelectric layer provided on the first electrode; and a second electrode provided on the piezoelectric layer. A method for manufacturing an element, comprising: mixing at least an organometallic compound constituting a ceramic thin film and water to form a ceramic thin film forming composition; cold cooling crystallization of the ceramic thin film forming composition; The step of storing at a temperature higher than the upper limit temperature of the peak region of crystallization and lower than the melting start temperature, and applying the ceramic thin film forming composition stored on the first electrode and firing to form the piezoelectric layer And a step of manufacturing the piezoelectric element.

In this aspect, it is possible to manufacture a piezoelectric element having excellent piezoelectric characteristics by suppressing the occurrence of variations in piezoelectric characteristics regardless of the storage period. In addition, there is a method for manufacturing a piezoelectric element in which there is no variation in piezoelectric characteristics for each product.

According to another aspect of the present invention, there is provided a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, a first electrode provided on the flow path forming substrate, and the first electrode A piezoelectric layer provided on the piezoelectric layer, and a second electrode provided on the piezoelectric layer, and a piezoelectric element corresponding to each pressure generating chamber. An organic metal compound constituting the ceramic thin film and water are mixed at least to form a ceramic thin film forming composition, and after the cold-crystallization of the ceramic thin film forming composition, the upper limit temperature of the cold crystallization peak region A step of storing at a temperature higher than the melting start temperature and a step of applying the ceramic thin film forming composition stored on the first electrode and firing to form the piezoelectric layer. Characteristic liquid jet In the manufacturing method of de.

In this aspect, it is possible to manufacture a liquid jet head having excellent piezoelectric characteristics while suppressing the occurrence of variations in piezoelectric characteristics regardless of the storage period. Further, it is possible to manufacture a liquid ejecting head having no variation in piezoelectric characteristics for each product.

The figure which shows the relationship of the heat flow with respect to the temperature change of the composition for ceramic thin film formation. The figure which shows the relationship of the heat flow with respect to the temperature change of Example 1 and Reference Example 1. FIG. FIG. 4 is an exploded perspective view illustrating a schematic configuration of a recording head according to a second embodiment. FIG. 6 is a plan view and a cross-sectional view of a recording head according to a second embodiment. FIG. 9 is a cross-sectional view illustrating a recording head manufacturing method according to a second embodiment. FIG. 9 is a cross-sectional view illustrating a recording head manufacturing method according to a second embodiment. FIG. 9 is a cross-sectional view illustrating a recording head manufacturing method according to a second embodiment. FIG. 9 is a cross-sectional view illustrating a recording head manufacturing method according to a second embodiment. FIG. 9 is a cross-sectional view illustrating a recording head manufacturing method according to a second embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
The method for preserving the composition for forming a ceramic thin film according to the present invention comprises: mixing at least an organometallic compound constituting the ceramic thin film and water to obtain a composition for forming a ceramic thin film; Then, it is stored at a temperature higher than the upper limit temperature of the peak region of cold crystallization and lower than the melting start temperature. This composition for forming a ceramic thin film is used in a chemical solution method such as a MOD method or a sol-gel method.

In the present invention, at least the organometallic compound constituting the ceramic thin film and water are mixed to form a ceramic thin film-forming composition, whereby the temperature can be lowered to cause cold crystallization. Here, the composition for forming a ceramic thin film to which water is not added does not undergo cold crystallization even when the temperature is lowered. However, the composition for forming a ceramic thin film according to the present invention adds a predetermined amount of water. Thus, cold crystallization can be achieved. Then, after the ceramic thin film forming composition is cold-crystallized, it is stored at a temperature higher than the upper limit temperature of the peak region of cold crystallization and lower than the melting start temperature. Since the molecular motion is suppressed in the cold crystallization state, the reaction of the organometallic compound, the solvent, and the additive in the ceramic thin film forming composition is suppressed. Thus, in the present invention, by storing the ceramic thin film forming composition in a cold crystal state,
The composition of the ceramic thin film forming composition is prevented from changing. Accordingly, the storage stability can be satisfactorily maintained over a long period.

FIG. 1 is a diagram showing the amount of heat with respect to temperature change of the ceramic thin film forming composition according to the present embodiment. Specifically, it shows the amount of heat (mW) measured when the ceramic thin film forming composition is cooled at a constant rate using a differential scanning calorimetry (DSC) device and then heated at a constant rate. The direction shows endotherm. FIG. 1 (1) is a DSC curve when the ceramic thin film forming composition according to this embodiment is cooled from 25 ° C. to −150 ° C. and then heated to 25 ° C. It is a DSC curve at the time of heating up to 25 degreeC, after cooling the composition for ceramic thin film formation concerning embodiment to 25 degreeC to -90 degreeC, (3
) Is a DSC curve when the ceramic thin film forming composition according to this embodiment is cooled from 25 ° C. to −40 ° C. and then heated to 25 ° C.

Here, the cold crystallization refers to a crystallization phenomenon that occurs when the temperature is raised from a glass state. For example, in a constant temperature raising process using a differential scanning calorimetry (DSC) apparatus, an exothermic peak (cold crystallization) It can be confirmed by observing a peak. Specifically, as shown in FIGS. 1 (1) and (2), heat is released by an exothermic reaction in a constant temperature heating process using a differential scanning calorimetry (DSC) device, and the DSC curve baseline is obtained. Those where the lower peak is observed are cold crystallized. In (3), no exothermic peak was observed, and no cold crystallization occurred. That is, cold crystallization of the composition for forming a ceramic thin film refers to lowering the temperature so that an exothermic peak is confirmed in a constant speed heating process using a differential scanning calorimetry (DSC) apparatus. The upper limit temperature of the peak region of cold crystallization according to the present invention refers to the temperature at which the cold crystallization proceeds and the DSC curve returns to the baseline. The melting start temperature is a temperature at which the crystal starts to melt, and refers to a position that is above the baseline of the DSC curve.
The melting temperature (Tm) is a temperature at which the crystal is completely melted, and indicates the peak top of the DSC curve.

In the ceramic thin film forming composition according to the present embodiment, a peak of cold crystallization is observed at −70 to −50 ° C., the melting start temperature is −25 ° C., and the melting temperature (Tm) is −12 ° C.
It is. Therefore, the composition for forming a ceramic thin film according to the present embodiment is a temperature (Ta) that is higher than −50 ° C. and lower than −25 ° C., which is the melting start temperature, after cold crystallization by lowering the temperature below −70 ° C. Save it with

The amount of water in the ceramic thin film forming composition may be an amount that allows the ceramic thin film forming composition to be cold-crystallized. For example, the amount of water in the ceramic thin film forming composition is 1 wt% or more. It is preferable to add so that it may become 1 to 25 wt%. The amount of water in the ceramic thin film forming composition is 25 wt%
This is because the viscosity of the composition for forming a ceramic thin film may be too low when the amount is larger.

The viscosity of the composition for forming a ceramic thin film according to the present invention is preferably 7.0 mPa · s or more and 25.0 mPa · s or less. Thereby, a ceramic thin film having a uniform film thickness can be formed. If it is less than 7.0 mPa · s, it may be difficult to obtain a desired film thickness. If it is higher than 25.0 mPa · s, the spread of the coating becomes poor, and a ceramic thin film having a uniform film thickness is formed. It may be difficult to do. In this invention, the fall of the viscosity of the composition for ceramic thin film formation after a preservation | save is suppressed. Therefore, by adjusting the amount of the solvent and the amount of water so that the viscosity of the ceramic thin film forming composition before storage is within the above range, the viscosity of the ceramic thin film forming composition after storage is within the above range. can do.

The composition for forming a ceramic thin film according to the present invention is a mixture of at least an organometallic compound constituting a ceramic thin film and water. Specifically, an organic metal compound constituting the ceramic thin film, water, a solvent, and other additives added as necessary are mixed.

Examples of the organometallic compound include alkoxides such as methoxide, ethoxide, propoxide, and butoxide of metals constituting the ceramic thin film, and acetate compounds. For example, in the case of a PZT thin film forming composition for forming a lead zirconate titanate (PZT) thin film, the metal constituting PZT, that is, lead (Pb), titanium (T
i), an alkoxide of zirconium (Zr), or an acetate compound is used.

Here, the ceramic thin film formed by the ceramic thin film forming composition is made of, for example, a ferroelectric material such as lead zirconate titanate (PZT) or a metal such as niobium, nickel, magnesium, bismuth or yttrium. Examples thereof include a piezoelectric ceramic thin film such as an added relaxor ferroelectric. As a composition of the piezoelectric ceramic thin film, for example, PbTiO
₃ (PT), PbZrO ₃ (PZ), Pb (Zr _x Ti _1-x ) O ₃ (PZT), Pb (
Mg _1/3 Nb _2/3 ) O ₃ —PbTiO ₃ (PMN-PT), Pb (Zn _1/3 Nb _{2
/ 3) O 3 -PbTiO 3 (} PZN-PT), Pb (Ni 1/3 Nb 2/3) O 3 -Pb
TiO ₃ (PNN-PT), Pb (In _1/2 Nb _1/2 ) O ₃ -PbTiO ₃ (PIN
_{-PT), Pb (Sc 1/2 Ta} 1/2) O 3 -PbTiO 3 (PST-PT), Pb (
_{Sc 1/2 Nb 1/2) O 3 -PbTiO} 3 (PSN-PT), BiScO 3 -PbTi
_{O 3 (BS-PT),} BiYbO 3 -PbTiO 3 (BY-PT) and the like. Further, the invention is not limited to the piezoelectric ceramic thin film described above, _{SiO 2,} AlO _x as used in the insulating film or a protective film or the like, _ZrO x, TiO x, SrO, include ceramic thin film such as MgO.

Examples of the solvent for the ceramic thin film forming composition include carboxylic acid and alcohol. Examples of alcohol include butanol, methyl cellosolve, butyl cellosolve,
2-n-butoxy alcohol, n-pentyl alcohol, 2-phenylethanol, 2-
Examples include phenoxyethanol, methoxyethanol, ethylene glycol monoacetate, triethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, and isoamyl acetate. Examples of the carboxylic acid include acetic acid,
Propionic acid, butyric acid, caprylic acid, octylic acid and the like can be mentioned. These solvents may be used alone or in combination.

Moreover, the composition for forming a ceramic thin film may further contain amines. When amines are contained, the dispersion stability of each component is improved. Examples of amines include alkanolamines such as monoethanolamine and diethanolamine. These amines may be used alone or in combination.

Furthermore, polyethylene glycol or the like may be contained as necessary as a stabilizer for stabilizing each component or preventing the occurrence of cracks in the formed ferroelectric film. Moreover, you may add a thickener etc. as another additive.

Hereinafter, the preservation method of the composition for forming a ceramic thin film of the present invention will be described in more detail based on Example 1 and Reference Example 1.

(Reference Example 1)
In an inert gas, titanium tetraisopropoxide was added to acetic acid and stirred. Next, zirconium tetra-n-butoxide was added and stirred, and then polyethylene glycol was added and further stirred. To this, lead acetate trihydrate was added and stirred.
Then, the mixture was naturally cooled to room temperature to obtain a precursor solution for forming PZT of Reference Example 1. At this time, the viscosity of the precursor solution for forming PZT was 8.0 mPa · s.

Example 1
Pure water was added to the PZT forming precursor solution of Reference Example 1 and stirred at room temperature, and PZT of Example 1 was stirred.
A thin film forming composition was obtained. The composition for forming a PZT thin film has an amount of water of 5 wt%,
The viscosity of the composition for forming a PZT thin film was 8.0 mPa · s.

(Test Example 1)
The PZT forming precursor solution of Reference Example 1 and the PZT thin film forming composition of Example 1 were cooled to 25 ° C. to −150 ° C. at a cooling rate of 10.00 ° C./min, and then the temperature rising rate was 10.00 ° C.
The temperature was raised to 25 ° C. at / min. FIG. 2 shows the relationship of heat flow (mW) to temperature change.

As shown in FIG. 2, in Reference Example 1 in which water was not added, cold crystallization did not occur even when stored at −150 ° C. or lower. On the other hand, cold crystallization was confirmed in the composition for forming a ceramic thin film of Example 1 obtained by adding water.

(Test Example 2)
Further, after the PZT forming precursor solution of Reference Example 1 and the PZT thin film forming composition of Example 1 were stored for a predetermined period, the viscosity at 25 ° C. was measured. In addition, the composition for PZT thin film formation of Example 1 was stored at -30 degreeC after cooling to -90 degreeC.

When the viscosity is 7.0 mPa · s or more and 25.0 mPa · s or less, ○, 7.0 mPa · s
When it became less than s, it evaluated as x. The results are shown in Table 1.

The PZT forming precursor solution of Reference Example 1 and the PZT thin film forming composition of Example 1 had an initial viscosity of 8.0 mPa · s, but the ceramic thin film forming composition of Reference Example 1 was It deteriorated with the passage of time, and the viscosity became less than 7.0 mPa · s. In contrast,
The composition for forming a ceramic thin film of Example 1 showed no change in viscosity even after storage for 3 months.

The method for preserving the composition for forming a ceramic thin film according to the present invention includes adding water to the composition for forming a ceramic thin film to form a composition for forming a ceramic thin film, and cold-crystallizing the composition for forming a ceramic thin film after cooling. It is stored at a temperature higher than the upper limit temperature of the crystallization peak region and lower than the melting start temperature. Thereby, storage stability can be kept favorable over a long period of time. The ceramic thin film forming composition stored by the method for storing a ceramic thin film forming composition of the present invention can be used in the same manner as a normal ceramic thin film forming composition by raising the temperature to room temperature. .

(Embodiment 2)
Embodiment 2 is an ink jet recording head manufacturing method which is an example of a liquid jet head manufacturing method.

FIG. 3 is an exploded perspective view illustrating a schematic configuration of an ink jet recording head which is an example of a liquid jet head according to Embodiment 2, and FIG. 4 is a plan view of FIG. 3 and a cross-sectional view taken along line AA ′ in FIG. .

As shown in the figure, the flow path forming substrate 10 is composed of a silicon single crystal substrate in this embodiment,
An elastic film 50 made of an oxide film is formed on one surface thereof.

A plurality of pressure generating chambers 12 are arranged in parallel in the width direction of the flow path forming substrate 10. Also,
A communication portion 13 is formed in a region outside the pressure generation chamber 12 in the longitudinal direction of the flow path forming substrate 10, and the communication portion 13 and each pressure generation chamber 12 are provided for each pressure generation chamber 12. 14 and the communication passage 15. The communication part 13 communicates with a reservoir part 31 of a protective substrate, which will be described later, and constitutes a part of a reservoir that becomes a common ink chamber of each pressure generating chamber 12.
The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13. In this embodiment, the ink supply path 14 is formed by narrowing the width of the flow path from one side. However, the ink supply path may be formed by narrowing the width of the flow path from both sides. Further, the ink supply path may be formed by narrowing from the thickness direction instead of narrowing the width of the flow path.

Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive. Or a heat-welded film or the like. The nozzle plate 20 is made of, for example, glass ceramics, a silicon single crystal substrate, or stainless steel.

On the other hand, the elastic film 50 is formed on the side opposite to the opening surface of the flow path forming substrate 10 as described above, and the insulator film 55 is formed on the elastic film 50. Further, the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are laminated on the insulator film 55 by a process described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 is the first
A portion including the electrode 60, the piezoelectric layer 70, and the second electrode 80 is referred to. In general, the piezoelectric element 30
One electrode of 0 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are connected to each pressure generating chamber 12.
Each pattern is formed by patterning. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the first electrode 60 is a common electrode of the piezoelectric element 300, and the second electrode 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. Also, here, the piezoelectric element 300 and the diaphragm that is displaced by driving the piezoelectric element 300 are collectively referred to as an actuator device. In the above-described example, the elastic film 50, the insulator film 55, and the first electrode 60 function as a diaphragm. However, the present invention is not limited to this. For example, the elastic film 50 and the insulator film 55 are provided. Without first electrode 6
Only 0 may act as a diaphragm. Further, the piezoelectric element 300 itself may substantially serve as a diaphragm.

In the present embodiment, the piezoelectric element 300 includes a first electrode 60 made of platinum, a piezoelectric layer 70 made of lead zirconate titanate (PZT), and a second electrode 80 made of iridium.
In the present embodiment, the first electrode 60 is made of platinum and the second electrode 80 is made of iridium. However, the present invention is not limited to this, and each of the first electrode 60 and the second electrode 80 is, for example, nickel. , Copper, niobium, ruthenium, rhodium, palladium, silver, tin, osmium, iridium, platinum, gold, bismuth, or a laminate or alloy thereof. Of course, the first electrode 60 and the second electrode 80 may be made of other conductive materials.

Here, the piezoelectric layer 70 is formed using the ferroelectric thin film forming composition stored by the above storage method. As will be described in detail later, the ceramic thin film forming composition stored on one side of the substrate is applied and fired. Thereby, regardless of the storage period, it is possible to suppress the occurrence of variations in piezoelectric characteristics and to have excellent piezoelectric characteristics.

The piezoelectric layer 70 is preferably, for example, a ferroelectric material such as lead zirconate titanate (PZT) or a material obtained by adding a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide. Specifically, lead titanate (PbTiO ₃ ), lead zirconate titanate (Pb (Z
r, Ti) O ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb,
La), TiO ₃ ), lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O
₃ ) or lead zirconium titanate magnesium niobate (Pb (Zr, Ti) (Mg,
Nb) O ₃ ) or the like can be used. Further, the thickness of the piezoelectric layer 70 may be reduced to such a level that cracks are not generated in the manufacturing process and thick enough to exhibit sufficient displacement characteristics. A thickness of 5 μm is preferred. In the present embodiment, the piezoelectric layer 70 is made of lead zirconate titanate (PZT) and has a monoclinic structure with a preferential orientation on the (100) plane, and is formed with a thickness of about 1 μm.

Further, each second electrode 80 which is an individual electrode of the piezoelectric element 300 is drawn from the vicinity of the end on the ink supply path 14 side and extended to the insulator film 55, for example, gold (Au) or the like. The lead electrode 90 which consists of is connected.

On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a protective substrate 30 having a reservoir portion 31 constituting at least a part of the reservoir 100 is bonded via an adhesive 35. In the present embodiment, the reservoir portion 31 is formed across the protective substrate 30 in the thickness direction and across the width direction of the pressure generating chamber 12, and as described above, the flow path forming substrate 1.
A reservoir 100 that is in communication with the zero communication portion 13 and serves as a common ink chamber for the pressure generation chambers 12.
Is configured. Alternatively, the communication portion 13 of the flow path forming substrate 10 may be divided into a plurality of pressure generation chambers 12 and only the reservoir portion 31 may be used as the reservoir. Further, for example, only the pressure generating chamber 12 is provided in the flow path forming substrate 10, and a reservoir is provided on a member (for example, the elastic film 50, the insulator film 55, etc.) interposed between the flow path forming substrate 10 and the protective substrate 30. An ink supply path 14 that communicates with each pressure generating chamber 12 may be provided.

A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region of the protective substrate 30 that faces the piezoelectric element 300. Piezoelectric element holder 32
Need only have a space that does not hinder the movement of the piezoelectric element 300, and the space may or may not be sealed.

As such a protective substrate 30, it is preferable to use substantially the same material as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material, etc. In this embodiment, the same material as the flow path forming substrate 10 is used. The silicon single crystal substrate was used.

The protective substrate 30 is provided with a through hole 33 that penetrates the protective substrate 30 in the thickness direction. The vicinity of the end portion of the lead electrode 90 drawn from each piezoelectric element 300 is provided so as to be exposed in the through hole 33.

A driving circuit 12 for driving the piezoelectric elements 300 arranged side by side on the protective substrate 30.
0 is fixed. For example, a circuit board or a semiconductor integrated circuit (IC) can be used as the drive circuit 120. The drive circuit 120 and the lead electrode 90 are electrically connected via a connection wiring 121 made of a conductive wire such as a bonding wire.

In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility, and one surface of the reservoir portion 31 is sealed by the sealing film 41. The fixing plate 42 is formed of a relatively hard material. Reservoir 1 of this fixed plate 42
Since the region facing 00 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41.

In the ink jet recording head 1 of this embodiment, after taking ink from an ink introduction port connected to an external ink supply means (not shown) and filling the interior from the reservoir 100 to the nozzle opening 21, the drive circuit In accordance with a recording signal from 120, a voltage is applied between each of the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the insulator film 55, the first electrode 60, and the piezoelectric body. By bending and deforming the layer 70, the pressure in each pressure generation chamber 12 is increased, and ink droplets are ejected from the nozzle openings 21.

Here, a method of manufacturing the ink jet recording head will be described with reference to FIGS. 5 to 9 are cross-sectional views showing a method for manufacturing the ink jet recording head.

First, as shown in FIG. 5A, silicon dioxide (SiO ₂₎ constituting an elastic film 50 on the surface of a flow path forming substrate wafer 110, which is a silicon wafer in which a plurality of flow path forming substrates 10 are integrally formed. ) Is formed. Next, as shown in FIG. 5B, an insulator film 55 made of, for example, zirconium oxide is formed on the elastic film 50 (silicon dioxide film 51).

Next, as shown in FIG. 5C, a first electrode 60 made of platinum is formed on the insulator film 55. Although the formation method of the 1st electrode 60 is not specifically limited, For example, sputtering method, chemical vapor deposition method (CVD method), physical vapor deposition method (PVD method) etc. are mentioned. The material of the first electrode 60 is not particularly limited as described above. However, when lead zirconate titanate (PZT) is used as the piezoelectric layer 70 as in the present embodiment, the conductivity due to diffusion of lead oxide. Therefore, platinum, iridium, or the like is preferably used as the material of the first electrode 60.

Next, a piezoelectric layer 70 made of lead zirconate titanate (PZT) or the like is formed on the entire surface of the flow path forming substrate wafer 110. A so-called sol in which a metal organic material is dissolved and dispersed in a solvent is applied and dried to be gelled, and further baked at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. Layer 70 was formed.

A specific procedure for creating the piezoelectric layer 70 will be described.
First, as shown in FIG. 6A, a ceramic thin film forming composition 71 is formed on the first electrode 60.
Is applied (application process). This ceramic thin film forming composition 71 is a ceramic thin film forming composition by mixing an organometallic compound constituting a ceramic thin film, water, a solvent, and other additives added as necessary. The ceramic thin film forming composition is cold-crystallized and then stored at a temperature higher than the upper limit temperature of the cold crystallization peak region and lower than the melting start temperature.

Next, the ceramic thin film forming composition 71 was heat-treated to form an amorphous ceramic precursor film 72 shown in FIG. Specifically, the ceramic thin film forming composition 71 is heated to a predetermined temperature and dried for a predetermined time to form the ceramic precursor film 72 (drying step). For example, in the drying process of the present embodiment, the ceramic thin film forming composition 71 applied on the flow path forming substrate wafer 110 can be dried by holding at 100 to 200 ° C. for 3 to 30 minutes.

Next, the ceramic precursor film 72 dried in the drying process is heated to a predetermined temperature and held for a certain period of time to degrease (degreasing process). In this embodiment, the dried ceramic precursor film 72 was degreased by heating to 200 to 400 ° C. and holding for about 3 to 30 minutes.
In addition, degreasing said here is an organic component contained in the ceramic precursor film | membrane 72, for example,
It is to be detached as _{NO 2, CO 2, H 2} O or the like.

Next, as shown in FIG. 6C, the ceramic precursor film 72 is crystallized by heating to a predetermined temperature and holding for a certain period of time to form a ceramic thin film 73 (firing step).
In this firing step, it is preferable to heat the ceramic precursor film 72 to 550 to 800 ° C. In this embodiment, the ceramic precursor film 72 is fired by heating at 680 ° C. for 5 to 30 minutes, and the ceramic thin film (Piezoelectric film) 73 was formed.

In addition, as a heating apparatus used in such a drying process, a degreasing process, and a baking process, for example, RTP (Rapid Thermal Pr) heated by irradiation of a hot plate or an infrared lamp is used.
ocessing) device or the like can be used.

Next, as shown in FIG. 7A, at the stage where the first ceramic thin film 73 is formed on the first electrode 60, the side surfaces of the first electrode 60 and the first ceramic thin film 73 are inclined. Pattern simultaneously. As a result, when the second ceramic thin film 73 is formed, two layers due to the difference in the ground are formed in the vicinity of the boundary between the portion where the first electrode 60 and the first ceramic thin film 73 are formed and the other portions. The adverse effect on the crystallinity of the ceramic thin film 73 can be reduced, that is, can be mitigated. Thereby, in the vicinity of the boundary between the first electrode 60 and other portions, the crystal growth of the second ceramic thin film 73 proceeds well, and the piezoelectric layer 70 having excellent crystallinity can be formed. In addition, by tilting the side surfaces of the first electrode 60 and the first-layer piezoelectric film 73, it is possible to improve the contact when forming the second and subsequent ceramic thin films 73. Thereby, the piezoelectric layer 70 having excellent adhesion and reliability can be formed. The patterning of the first electrode 60 and the first piezoelectric film 73 can be performed by dry etching such as ion milling, for example.

Next, as shown in FIG. 7B, the above-described coating process, drying process, degreasing process, and baking process are sequentially repeated on the flow path forming substrate wafer 110 including the first piezoelectric film 73. As a result, a piezoelectric layer 70 having a thickness of 1 μm composed of a plurality of ceramic thin films (piezoelectric films) 73 is formed. Incidentally, in the present embodiment, the piezoelectric layer 70 is illustrated as having a plurality of ceramic thin films (piezoelectric films) 73, but the piezoelectric layer 70 is formed from a single ceramic thin film (piezoelectric film) 73. It may be.

Next, after forming a second electrode 80 made of iridium (Ir) over the piezoelectric layer 70 made of a plurality of piezoelectric films 73, as shown in FIG. 5D, the piezoelectric layer 70 is formed. And the second electrode 8
The piezoelectric element 300 is formed by patterning 0 in a region facing each pressure generating chamber 12.
Examples of the patterning method of the piezoelectric layer 70 and the second electrode 80 include dry etching such as reactive ion etching and ion milling.

Next, the lead electrode 90 is formed. Specifically, as shown in FIG. 8A, after the lead electrode 90 made of, for example, gold (Au) is formed over the entire surface of the flow path forming substrate wafer 110, it is made of, for example, a resist or the like. Each piezoelectric element 30 is passed through a mask pattern (not shown).
It is formed by patterning every zero.

Next, as shown in FIG. 8B, a protective substrate wafer 130 which is a silicon wafer and serves as a plurality of protective substrates 30 is bonded to the piezoelectric element 300 side of the flow path forming substrate wafer 110 by an adhesive 35. . The protective substrate 30 includes a reservoir portion 31 and a piezoelectric element holding portion 3.
2 etc. are formed in advance. Further, the protective substrate 30 is made of, for example, a silicon single crystal substrate having a thickness of about 400 μm, and the rigidity of the flow path forming substrate 10 is remarkably improved by bonding the protective substrate 30. Then, as shown in FIG. 8C, the flow path forming substrate wafer 110 is set to a predetermined thickness.

Next, as shown in FIG. 9A, a mask film 52 is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape. Then, as shown in FIG. 9B, the flow path forming substrate wafer 110 is anisotropically etched (wet etching) using an alkaline solution such as KOH through the mask film 52, thereby forming the piezoelectric element 300. Corresponding pressure generating chambers 12, communication portions 13, ink supply passages 14, communication passages 15 and the like are formed.

Thereafter, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer 130 are removed by cutting, for example, by dicing. The nozzle opening 21 is formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130.
3 is bonded to the protective substrate wafer 130, and the flow path forming substrate wafer 110 and the like are formed into a single chip size flow path forming substrate as shown in FIG. By dividing into 10 or the like, the ink jet recording head 1 of the present embodiment is obtained.

As described above, in the ink jet recording head manufacturing method according to this embodiment,
An organic metal compound constituting the ceramic thin film and water are mixed at least to form a ceramic thin film forming composition, and after the cold-crystallization of the ceramic thin film forming composition, the upper limit temperature of the cold crystallization peak region A step of storing at a temperature higher than the melting start temperature and a step of applying the ceramic thin film forming composition stored on the first electrode and firing to form the piezoelectric layer. Regardless of the storage period, the occurrence of variations in piezoelectric characteristics can be suppressed, and a liquid jet head having excellent piezoelectric characteristics can be manufactured. In addition, since the composition for forming a ceramic thin film stored by a storage method having excellent storage stability is used,
There is no variation in piezoelectric characteristics for each product, and a liquid ejecting head having stable piezoelectric characteristics can be manufactured.

In the second embodiment described above, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention is widely applied to all liquid ejecting heads, and is a liquid ejecting liquid other than ink. Of course, the present invention can also be applied to an ejection head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, and organic E
Examples thereof include electrode material ejection heads used for electrode formation such as L display and FED (field emission display), bio-organic matter ejection heads used for biochip production, and the like.

(Other embodiments)
The ceramic thin film forming composition stored by the method for storing a ceramic thin film forming composition of the present invention includes, for example, a ferroelectric memory, an infrared sensor, an ultrasonic sensor, a thermal sensor, a pressure sensor, a pyroelectric sensor, and the like. Ferroelectric films used for various sensors, SAW devices, etc., piezoelectric elements mounted on microphones, sound generators, various vibrators, transmitters, etc., piezoelectric elements mounted on micro liquid pumps, etc. It can be used suitably for forming.

1 ink jet recording head, 10 flow path forming substrate, 12 pressure generating chamber, 1
3 communication part, 14 ink supply path, 20 nozzle plate, 21 nozzle opening,
30 protective substrate, 40 compliance substrate, 60 first electrode, 70 piezoelectric layer, 71 ceramic thin film forming composition, 72 ceramic precursor film, 73 ceramic thin film, 80 second electrode, 90 lead electrode, 300 piezoelectric element

Claims (8)

A composition for forming a ceramic thin film is obtained by mixing at least an organometallic compound constituting the ceramic thin film and water,
A method for preserving a composition for forming a ceramic thin film, comprising cold crystallization of the composition for forming a ceramic thin film and then storing the composition at a temperature higher than an upper limit temperature of a peak region of cold crystallization and lower than a melting start temperature. The method for storing a composition for forming a ceramic thin film according to claim 1, wherein the composition for forming a ceramic thin film is a composition for forming a piezoelectric ceramic thin film. 3. The method for preserving a composition for forming a ceramic thin film according to claim 1 or 2, wherein the composition for forming a ceramic thin film contains at least lead, titanium, and zirconium. Method. The ceramic thin film forming composition according to any one of claims 1 to 3, wherein the ceramic thin film forming composition contains at least one of alcohol and carboxylic acid. A method for preserving the forming composition. 5. The method for storing a composition for forming a ceramic thin film according to claim 1, wherein the viscosity of the composition for forming a ceramic thin film after storage is 7.0 mPa · s or more and 25.0 mP.
The preservation | save method of the composition for ceramic thin film formation characterized by being below a * s. An organic metal compound constituting the ceramic thin film and water are mixed at least to form a ceramic thin film forming composition, and after the cold-crystallization of the ceramic thin film forming composition, the upper limit temperature of the cold crystallization peak region Storing at a temperature higher than the melting start temperature,
Applying a ceramic thin film forming composition stored on one side of the substrate and firing to form a ceramic thin film; and
A method for producing a ceramic thin film, comprising: A method of manufacturing a piezoelectric element comprising a first electrode provided on a substrate, a piezoelectric layer provided on the first electrode, and a second electrode provided on the piezoelectric layer,
An organic metal compound constituting the ceramic thin film and water are mixed at least to form a ceramic thin film forming composition, and after the cold-crystallization of the ceramic thin film forming composition, the upper limit temperature of the cold crystallization peak region Storing at a temperature higher than the melting start temperature,
Applying the ceramic thin film forming composition stored on the first electrode and firing to form the piezoelectric layer;
A method for manufacturing a piezoelectric element, comprising: A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed;
A first electrode provided on the flow path forming substrate; a piezoelectric layer provided on the first electrode;
A second electrode provided on the piezoelectric layer, and a piezoelectric element corresponding to each pressure generating chamber;
A method of manufacturing a liquid jet head comprising:
An organic metal compound constituting the ceramic thin film and water are mixed at least to form a ceramic thin film forming composition, and after the cold-crystallization of the ceramic thin film forming composition, the upper limit temperature of the cold crystallization peak region Storing at a temperature higher than the melting start temperature,
Applying the ceramic thin film forming composition stored on the first electrode and firing to form the piezoelectric layer;
A method of manufacturing a liquid jet head, comprising:

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