JP2011103372A - Method for manufacturing piezoelectric membrane, method for manufacturing piezoelectric element, and method for manufacturing liquid jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain: a method for manufacturing a piezoelectric membrane whose crystal states such as crystal grain size and orientation are stable; a method for manufacturing a piezoelectric element whose displacement is secured, and to provide a liquid jet head. <P>SOLUTION: When a shelf time T after a degreasing step (S4) is set to be within six hours at a normal temperature and humidity, influences of water or the like on a piezoelectric membrane precursor laminate 72 are prevented in an atmosphere and the crystal states such as the crystal grain size and orientation of the burned piezoelectric membrane 73 are stable, thereby obtaining the method for manufacturing the piezoelectric membrane 73 whose piezoelectric performance is stable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a piezoelectric film, a method for manufacturing a piezoelectric element including a piezoelectric layer made of a piezoelectric film, and a method for manufacturing a liquid ejecting head including a piezoelectric element.

  A piezoelectric element used for a liquid ejecting head or the like is an element in which a piezoelectric layer made of a piezoelectric film having piezoelectricity is sandwiched between two electrodes, and the piezoelectric film is made of, for example, crystallized piezoelectric ceramics. ing.

In addition, as a liquid ejecting head using such a piezoelectric element, for example, a part of a pressure generation chamber communicating with a nozzle opening for ejecting ink droplets is configured by a diaphragm, and the diaphragm is deformed by the piezoelectric element. There is an ink jet recording head that pressurizes ink in a pressure generating chamber and ejects ink droplets from nozzle openings.
Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator. As an example of using a piezoelectric actuator in a flexural vibration mode, for example, a uniform piezoelectric film is formed over the entire surface of the diaphragm by a film forming technique, and the piezoelectric layer made of the piezoelectric film is formed by a lithography method. It is known that piezoelectric elements are formed so as to be independent of each pressure generating chamber by cutting into shapes corresponding to the above.

A so-called sol-gel method is known as a method for manufacturing a piezoelectric film. In the sol-gel method, at least a drying process in which a sol that is a colloidal solution of an organometallic compound is applied to a substrate on which a lower electrode film is formed and a degreasing process in which a precursor film of a piezoelectric body is formed by gelation are formed. This is carried out one or more times, and then a baking step is performed in which heat treatment is performed at a high temperature for crystallization. A piezoelectric layer having a predetermined thickness is manufactured by repeating these steps a plurality of times.
In the method of manufacturing a piezoelectric film constituting a piezoelectric element, the drying process is divided into a first drying process and a second drying process, and the heating temperature, heating time, and temperature rising rate of the drying process, degreasing process, and firing process are set. For example, a method of controlling the crystal state of the piezoelectric film such as the crystal grain size and orientation is known (see, for example, Patent Document 1).

JP 2006-49792 A (pages 7 to 12, FIG. 7)

  However, since there is no knowledge about the influence of the leaving time between the degreasing process and the firing process on the crystal state of the piezoelectric film, such as the crystal grain size and orientation, the leaving time between the processes is caused by troubles during manufacturing. When it fluctuates, the crystal state such as the crystal grain size and orientation of the piezoelectric film changes. If the piezoelectricity of the piezoelectric element changes due to the change in the crystal state and the amount of vibration displacement decreases, it is difficult to obtain the amount of liquid ejection required for the liquid ejection head.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms or application examples.

[Application Example 1]
A coating step of coating a colloidal solution containing an organometallic compound containing at least lead to form a piezoelectric precursor film; and heating the piezoelectric precursor film to form the colloidal solution from the piezoelectric precursor film. A drying step for evaporating the solvent, a degreasing step for heating the piezoelectric precursor film to release organic components from the piezoelectric precursor film, and a standing time after the degreasing step are in a state of normal temperature and normal humidity And a firing step in which the piezoelectric precursor film is fired after being allowed to stand to form a piezoelectric film.

  According to this application example, by leaving the standing time after the degreasing process within 6 hours at room temperature and normal humidity, the influence of water in the atmosphere on the piezoelectric precursor film is suppressed, and the firing is performed. The crystal state of the piezoelectric film such as crystal grain size and orientation is stabilized. Therefore, a method for manufacturing a piezoelectric film with stable piezoelectricity can be obtained.

[Application Example 2]
In the method of manufacturing a piezoelectric film, the piezoelectric film is lead zirconate titanate (PZT).
In this application example, a piezoelectric film having a (100) orientation ratio of lead zirconate titanate (PZT) of 85% or more is obtained. Therefore, a method for producing a lead zirconate titanate (PZT) piezoelectric film with stable piezoelectricity can be obtained by aligning the orientation.
Here, the (100) orientation ratio of lead zirconate titanate (PZT) is represented by I (100) / (I (100) + I (110) + I (111)), where I is the diffraction intensity.

[Application Example 3]
In the method for manufacturing a piezoelectric film, the normal temperature is 22 ° C. ± 3 ° C., and the normal humidity is 45% ± 10%.
In this application example, since the leaving environment is normal temperature and normal humidity, the energy required for controlling the environment can be reduced. Therefore, a method for manufacturing a piezoelectric film with reduced manufacturing costs can be obtained.

[Application Example 4]
A step of forming a lower electrode film on the substrate, a step of forming a piezoelectric layer made of the piezoelectric film manufactured by the manufacturing method described above on the lower electrode film, and an upper surface of the piezoelectric layer. And a step of forming an electrode film.

  According to this application example, since the piezoelectric element includes the piezoelectric layer made of the piezoelectric film having stable piezoelectric performance, a method for manufacturing the piezoelectric element in which the amount of vibration displacement is ensured can be obtained.

[Application Example 5]
A method of manufacturing a liquid ejecting head, comprising using the piezoelectric element manufactured by the manufacturing method described above.

  According to this application example, it is possible to obtain a method of manufacturing a liquid ejecting head having the above-described effects and ensuring a necessary liquid ejecting amount.

FIG. 3 is an exploded perspective view of the ink jet recording head in the embodiment. FIG. 4A is a partial plan view of an ink jet recording head, and FIG. FIG. 6 is a partial cross-sectional view illustrating a method for manufacturing an ink jet recording head. The flowchart figure which shows the specific formation procedure of a piezoelectric material layer. The fragmentary sectional view which shows the specific formation procedure of a piezoelectric material layer. The temperature profile figure which shows the manufacturing method of a piezoelectric material film. The X-ray-diffraction pattern figure of a piezoelectric material film when leaving times differ. The figure which shows the leaving time dependence of the orientation rate of PZT (100). FIG. 6 is a partial cross-sectional view illustrating a method for manufacturing an ink jet recording head. FIG. 6 is a partial cross-sectional view illustrating a method for manufacturing an ink jet recording head.

Hereinafter, the present invention will be described in detail based on embodiments.
FIG. 1 is an exploded perspective view of an ink jet recording head 1 as a liquid ejecting head. 2A is a partial plan view of the ink jet recording head 1, and FIG. 2B is a cross-sectional view taken along line AA in FIG.
1 and 2, the ink jet recording head 1 includes a flow path forming substrate 10, a nozzle plate 20, and a protective substrate 30.

The flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110), and one surface thereof is made of silicon dioxide previously formed by thermal oxidation, and has an elastic film 50 with a thickness of 0.50 μm to 2.00 μm. Is formed.
A plurality of pressure generating chambers 12 are arranged in parallel in the width direction of the flow path forming substrate 10. Further, a communication portion 13 is formed in a region outside the longitudinal direction of the pressure generation chamber 12 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. Communication is made via a path 14.
The communication portion 13 is in communication with the reservoir portion 32 of the protective substrate 30 and constitutes a part of a reservoir that serves as a common ink chamber for the pressure generation chambers 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.

A mask film 52 for forming the pressure generating chambers 12 and the like is formed by etching on the opening surface side of the flow path forming substrate 10, and in the vicinity of the end of each pressure generating chamber 12 on the side opposite to the ink supply path 14. A nozzle plate 20 having a communicating nozzle opening 21 is fixed through an adhesive, a heat-welded film, or the like.
The nozzle plate 20 has a thickness of, for example, 0.01 mm to 1.00 mm and a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.]. It consists of a silicon single crystal substrate or non-rust steel.

On the other hand, an insulator film 55 made of zirconium oxide (ZrO 2) having a thickness of, for example, about 0.40 μm is formed on the elastic film 50.
Further, on the insulator film 55 as a substrate, a lower electrode film 60 having a thickness of, for example, about 0.20 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.00 μm, and a thickness of, for example, An upper electrode film 80 having a thickness of about 0.05 μm is laminated by a process to be described later to constitute the piezoelectric element 300.
Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. 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 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. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber.
Also, here, the piezoelectric element 300 and the diaphragm that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In addition, a lead electrode 90 made of, for example, gold (Au) or the like is connected to the upper electrode film 80 of each piezoelectric element 300, and a voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90. Is applied.

Examples of the material of the piezoelectric layer 70 constituting the piezoelectric element 300 include a ferroelectric piezoelectric material such as lead zirconate titanate (PZT), niobium, nickel, magnesium, bismuth, A relaxor ferroelectric material to which a metal such as yttrium is added is used. The composition may be appropriately selected in consideration of the characteristics, use, etc. of the piezoelectric element 300. 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 -PbTiO 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 -PbTiO 3 (BS-PT), BiYbO 3 -PbTiO 3 (BY-PT) and the like.

Further, a protective substrate 30 having a piezoelectric element holding portion 31 capable of securing a space that does not hinder its movement in a region facing the piezoelectric element 300 is bonded to the surface on the piezoelectric element 300 side on the flow path forming substrate 10. Has been. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment.
Further, the protective substrate 30 is provided with a reservoir portion 32 in a region corresponding to the communication portion 13 of the flow path forming substrate 10. The reservoir portion 32 is provided along the direction in which the pressure generating chambers 12 are arranged so as to penetrate the protective substrate 30 in the thickness direction, and communicated with the communication portion 13 of the flow path forming substrate 10 as described above. A reservoir 100 serving as an ink chamber common to the pressure generation chambers 12 is configured.

  Further, a through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 31 and the reservoir portion 32 of the protective substrate 30, and the lower electrode film 60 is provided in the through hole 33. A part of the lead electrode 90 and the tip of the lead electrode 90 are exposed, and one end of a connection wiring extending from the drive IC is connected to the lower electrode film 60 and the lead electrode 90, although not shown.

  In addition, examples of the material of the protective substrate 30 include glass, ceramic material, metal, resin, and the like, but it is more preferable that the material is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. For example, a silicon single crystal substrate made of the same material as the flow path forming substrate 10 can be used.

A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. The sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm). The sealing film 41 seals one surface of the reservoir portion 32. Yes.
The fixing plate 42 is formed of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 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. Has been.

  In the ink jet recording head 1, ink is taken in from an external ink supply unit (not shown), and the interior from the reservoir 100 to the nozzle opening 21 is filled with ink. Thereafter, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 in accordance with a recording signal from a drive IC (not shown), and the elastic film 50, the insulator film 55, the lower electrode By bending and deforming the film 60 and the piezoelectric layer 70, the pressure in each pressure generating chamber 12 is increased and ink droplets are ejected from the nozzle openings 21.

A method for manufacturing the ink jet recording head 1 will be described below with reference to FIGS.
FIG. 3 is a partial cross-sectional view showing a method for manufacturing the ink jet recording head 1.
In FIG. 3A, a flow path forming substrate wafer 110, which is a silicon wafer, is thermally oxidized in a diffusion furnace at about 1100 ° C. to form a silicon dioxide film 51 constituting an elastic film 50 on the surface thereof.
For example, a silicon wafer having a relatively thick plate thickness of about 625 μm and high rigidity can be used as the flow path forming substrate wafer 110.

In FIG. 3B, an insulator film 55 made of zirconium oxide is formed on the silicon dioxide film 51 that becomes the elastic film 50. Specifically, first, a zirconium layer is formed on the elastic film 50 by, for example, DC sputtering, and the zirconium film is thermally oxidized to form the insulator film 55 made of zirconium oxide.
Next, in FIG. 3C, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 55, the lower electrode film 60 is patterned into a predetermined shape.

  In FIG. 3D, a piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) is formed. Here, a so-called sol-gel method is used in which a so-called colloidal solution in which a metal organic material is dissolved / dispersed in a catalyst is applied and dried to be gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. A piezoelectric layer 70 is formed. The material of the piezoelectric layer 70 is not limited to lead zirconate titanate as described above.

  FIG. 4 is a flowchart showing a specific procedure for forming the piezoelectric layer 70. The method for manufacturing the ink jet recording head 1 includes a drying step, a degreasing step, and a firing step as a method for forming the piezoelectric layer 70. In the embodiment, step 1 (S1) as a coating process, step 2 (S2) as a first drying process as a drying process, step 3 (S3) as a second drying process as a drying process, and degreasing Step 4 (S4) as a process and Step 5 (S5) as a baking process are included. Here, the drying step may be a single step.

  FIG. 5 is a partial cross-sectional view showing a specific procedure for forming the piezoelectric layer 70. FIG. 6 is a temperature profile diagram showing the first drying step (S2), the second drying step (S3), the degreasing step (S4), and the firing step (S5).

First, in FIG. 5D-1, a piezoelectric precursor film 71 is formed on the lower electrode film 60 in the coating step (S 1). That is, a sol which is a colloidal solution containing a metal organic compound is applied onto the flow path forming substrate wafer 110 on which the lower electrode film 60 is formed.
Next, as a first drying step (S2), the piezoelectric precursor film 71 is heated from room temperature to a temperature lower than the boiling point of the solvent that is the main solvent of the colloidal solution and dried for a certain period of time to evaporate the solvent of the colloidal solution. By doing so, the piezoelectric precursor film 71 is dried.

Here, the main solvent of the colloid solution is not particularly limited, but for example, an ethanol-based solvent is preferably used. For example, 2-n-butoxyethanol having a boiling point of 176 ° C. can be used.
In FIG. 6, in the first drying step (S2), the applied sol is heated to a boiling point of the solvent of 176 ° C. (indicated by a broken line in the figure) or less, for example, about 90 ° C. to 110 ° C. for 2 minutes to 8 minutes. The piezoelectric precursor film 71 is dried by holding it for about a minute.

In the second drying step (S3), by heating the piezoelectric precursor film 71 again, for example, the temperature is raised to a temperature higher than that in the first drying step (S2) and maintained for a certain period of time. The piezoelectric precursor film 71 is dried by evaporation.
In FIG. 6, it is preferable that the ultimate temperature in a 2nd drying process (S3) is about 150 to 170 degreeC. The drying time is preferably about 2 minutes to 5 minutes. For example, in the second drying step (S3), the temperature is raised to about 160 ° C. and held for about 3 minutes. For example, when the ultimate temperature is 170 ° C., it may be held for about 2 minutes.

Furthermore, it is preferable that the temperature increase rate in this 2nd drying process (S3) is 0.5-1.5 [degreeC / sec].
The “temperature increase rate” referred to here is the time from the temperature at which the temperature difference between the temperature at the start of heating (room temperature) and the attained temperature increases by 20% to the temperature at which the temperature difference reaches 80%. It is defined as the rate of change. For example, when the temperature is raised from room temperature 25 ° C. to 100 ° C. in 50 seconds, the rate of temperature rise is (100−25) × (0.8−0.2) /50=0.9 [° C./sec]. Become.

  In addition, examples of the heating device used in such a drying process include a clean oven (diffusion furnace), a baking device, and the like. In particular, it is preferable to use a baking device. This is because in the clean oven, the temperature is controlled by applying hot air, so that the characteristics of the piezoelectric precursor film 71 are likely to vary in the in-plane direction of the flow path forming substrate wafer 110.

In FIG. 5, in the degreasing step (S4), after the piezoelectric precursor film 71 is dried by the first and second drying steps (S2, S3), the piezoelectric precursor film 71 is further heated in the air atmosphere at a constant temperature for a predetermined time. The body precursor film 71 is degreased.
Here, degreasing refers, the organic components of the sol film, for example, is to be detached as _{NO 2, CO 2, H 2} O or the like.

The heating method in the degreasing step (S4) is not particularly limited, but the flow path is formed on the hot plate through a jig that is an aluminum plate having a predetermined outer diameter slightly larger than the flow path forming substrate wafer 110. The substrate wafer 110 is placed, and the piezoelectric precursor film 71 is raised to a predetermined temperature.
In FIG. 6, the ultimate temperature in the degreasing step (S4) is preferably higher than the boiling point of the solvent that is the main solvent of the colloidal solution by a temperature selected from the range of 100 ° C to 300 ° C. For example, when the boiling point of the solvent is 176 ° C., the degreasing temperature is preferably in the range of 276 ° C. to 476 ° C., and more preferably in the range of 300 ° C. to 400 ° C. This is because crystallization starts when the temperature is too high, and sufficient degreasing cannot be performed when the temperature is too low. Moreover, it is preferable to perform a degreasing process for 2 minutes or more.
For example, in the degreasing step (S4), the piezoelectric precursor film 71 is degreased by raising the dried piezoelectric precursor film 71 to about 300 ° C. to 400 ° C. and holding it for about 3 minutes.

Further, in order to improve the crystallinity of the piezoelectric layer 70 shown in FIGS. 1 and 2, the temperature increase rate in the degreasing step (S4) is important.
Specifically, the temperature rising rate in the degreasing step is preferably 15 to 25 [° C./sec], whereby the (100) orientation strength of the piezoelectric layer 70 can be improved, and the wafer for flow path forming substrate The variation in the orientation strength in the in-plane direction of 110 can also be suppressed.

  As used herein, the term “temperature increase rate” refers to a temperature that is 80% of the temperature difference from a temperature that is 20% higher than the temperature difference between the temperature at the start of heating (room temperature) and the ultimate temperature. It is the time change rate of the temperature until it reaches.

Then, by repeating the coating process, the first drying process, the second drying process, and the degreasing process a predetermined number of times, for example, twice, as shown in FIG. The body laminated film 72 is formed.
Note that the number of repetitions is not limited to two, but may be one or three or more.

After the piezoelectric precursor multilayer film 72 having a predetermined thickness is formed, in the firing step (S5), the piezoelectric precursor multilayer film 72 is crystallized by heat treatment to form the piezoelectric film 73.
In FIG. 6, although the sintering conditions differ depending on the material, for example, heating is performed at 740 ° C. for 5 minutes to fire the piezoelectric precursor multilayer film 72 to form the piezoelectric film 73.
In addition, as a heating apparatus, a diffusion furnace can be used, and for example, an RTA (Rapid Thermal Annealing) apparatus may be used.

Moreover, in FIG. 6, let the leaving time T between a degreasing process (S4) and a baking process (S5) be less than 6 hours. Further, the leaving environment was 22 ° C. ± 3 ° C. at normal temperature and 45% ± 10% of normal humidity.
FIG. 7 shows an X-ray diffraction pattern diagram of the piezoelectric film 73 when the standing time T between the degreasing step (S4) and the firing step (S5) is different. A shows the case where the leaving time T is 1 hour, and B shows the case where the leaving time T is 3 days. The horizontal axis is 2θ, and the vertical axis is the diffraction intensity I.
In FIG. 7, it can be seen that the peak of (110) is larger when the standing time T is 3 days than when the standing time T is 1 hour. The orientation ratio of PZT (100) is set to I (100) / (I (100) + I (110) + I (111)) using the diffraction intensity I.

FIG. 8 is a graph showing the dependence of the orientation rate of PZT (100) on the standing time. The horizontal axis represents the standing time T (minutes) on a logarithmic scale, and the vertical axis represents the orientation ratio of PZT (100).
In FIG. 8, A is 98 minutes (96.9%), 105 minutes (99.2%), 115 minutes (97.1%), B is 4320 minutes (64%), C is 158 minutes, 164 minutes, 165 minutes, D represents a standing time T (orientation ratio in parentheses) of 60 minutes (98%). In the semilogarithmic graph, it can be seen that the orientation rate of PZT (100) decreases linearly as the standing time T increases.
The orientation rate has a correlation with the piezoelectric performance of the piezoelectric body and the displacement of the piezoelectric actuator, and also depends on the driving voltage. However, when an appropriate amount of displacement is obtained in the range of 10 to 40 V that is normally used, it is 85% or more. For this purpose, it is desirable to limit the standing time within 6 hours.

  And it shows in FIG.5 (d-3) by repeating the application | coating process (S1) mentioned above, the 1st and 2nd drying process (S2, S3), a degreasing process (S4), and a baking process (S5) several times. As described above, the piezoelectric layer 70 having a predetermined thickness composed of the five piezoelectric films 73 is formed. For example, when the thickness of the piezoelectric precursor film 71 is about 0.1 μm, the total thickness of the piezoelectric layer 70 is about 1 μm.

9 and 10 are partial cross-sectional views showing a method for manufacturing the ink jet recording head 1.
In FIG. 9E, after the piezoelectric layer 70 is formed, an upper electrode film 80 made of, for example, iridium is formed on the entire surface of the flow path forming substrate wafer 110.
In FIG. 9 (f), the piezoelectric layer 300 is formed by patterning the piezoelectric layer 70 and the upper electrode film 80 in regions facing the pressure generation chambers 12.
In FIG. 9G, the lead electrode 90 is formed next. Specifically, a metal layer 91 made of, for example, gold (Au) or the like is formed over the entire surface of the flow path forming substrate wafer 110. Thereafter, for example, the lead electrode 90 is formed by patterning the metal layer 91 for each piezoelectric element 300 through a mask pattern (not shown) made of a resist or the like.

  In FIG. 9 (h), a protective substrate wafer 130 that is a silicon wafer and serves as a plurality of protective substrates 30 is bonded to the flow path forming substrate wafer 110 on the piezoelectric element 300 side. Since the protective substrate wafer 130 has a thickness of, for example, about 400 μm, the rigidity of the flow path forming substrate wafer 110 is significantly improved by bonding the protective substrate wafer 130.

In FIG. 10I, after the flow path forming substrate wafer 110 is polished to a certain thickness, the flow path forming substrate wafer 110 is made to have a predetermined thickness by wet etching with fluorinated nitric acid. For example, the flow path forming substrate wafer 110 was etched so as to have a thickness of about 70 μm.
In FIG. 10J, a mask film 52 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape. Then, the flow path forming substrate wafer 110 is anisotropically etched through the mask film 52, whereby, as shown in FIG. 13 and the ink supply path 14 are formed.

  After that, 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 plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 130. The ink jet recording head 1 of this embodiment is obtained by dividing the flow path forming substrate wafer 110 and the like into a single chip size flow path forming substrate 10 and the like as shown in FIG.

According to the embodiment described above, the following effects can be obtained.
(1) By leaving the standing time T after the degreasing step (S4) within 6 hours at room temperature and normal humidity, the influence of water or the like in the atmosphere on the piezoelectric precursor laminated film 72 can be suppressed, The crystal state such as the crystal grain size and orientation of the fired piezoelectric film 73 can be stabilized. Therefore, a method for manufacturing the piezoelectric film 73 with stable piezoelectricity can be obtained.

  (2) The piezoelectric film 73 having a (100) orientation ratio of lead zirconate titanate (PZT) of 85% or more can be obtained. Therefore, by aligning the orientation, a method for producing the lead zirconate titanate (PZT) piezoelectric film 73 with stable piezoelectric performance can be obtained.

  (3) Since the standing environment is normal temperature and humidity, the energy required for environmental control can be reduced. Therefore, a method for manufacturing the piezoelectric film 73 with reduced manufacturing costs can be obtained.

  (4) Since the piezoelectric element 300 includes the piezoelectric layer 70 composed of the piezoelectric film 73 with stable piezoelectric performance, a method for manufacturing the piezoelectric element 300 in which the amount of vibration displacement is ensured can be obtained.

  (5) A method of manufacturing the ink jet recording head 1 having the above-described effects and ensuring a necessary liquid ejection amount can be obtained.

  In the above-described embodiment, the ink jet recording head 1 is described as an example of the liquid ejecting head. However, the ink jet recording head 1 is widely used as a general target, and the liquid ejecting head ejects liquid other than ink. Of course, it is also applicable. 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, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording head, 10 ... Channel formation board | substrate, 12 ... Pressure generating chamber, 13 ... Communication part, 14 ... Ink supply path, 20 ... Nozzle plate, 21 ... Nozzle opening, 30 ... Protection board, 31 ... Piezoelectric element Holding part, 32 ... reservoir part, 33 ... through hole, 40 ... compliance substrate, 41 ... sealing film, 42 ... fixing plate, 43 ... opening part, 50 ... elastic film, 52 ... mask film, 55 ... insulator film, 60 ... Lower electrode film, 70 ... Piezoelectric layer, 71 ... Piezoelectric precursor film, 72 ... Piezoelectric precursor laminated film, 73 ... Piezoelectric film, 80 ... Upper electrode film, 90 ... Lead electrode, 110 ... Flow path Wafer for forming substrate, 130 ... wafer for protective substrate, 300 ... piezoelectric element.

Claims (5)

A coating step of coating a colloidal solution containing an organometallic compound containing at least lead to form a piezoelectric precursor film;
A drying step of heating the piezoelectric precursor film and evaporating the solvent of the colloidal solution from the piezoelectric precursor film;
A degreasing step of heating the piezoelectric precursor film to release organic components from the piezoelectric precursor film;
A standing time after the degreasing step is 6 hours or less at room temperature and normal humidity, and includes a firing step in which the piezoelectric precursor film is fired to form a piezoelectric film. Manufacturing method of body membrane. The method of manufacturing a piezoelectric film according to claim 1,
The method for producing a piezoelectric film, wherein the piezoelectric film is lead zirconate titanate (PZT). In the method for manufacturing a piezoelectric film according to claim 1 or 2,
The normal temperature is 22 ° C. ± 3 ° C., and the normal humidity is 45% ± 10%. Forming a lower electrode film on the substrate;
Forming a piezoelectric layer including a piezoelectric film manufactured by the manufacturing method according to claim 1 or 2 on the lower electrode film;
Forming an upper electrode film on the piezoelectric layer. A method of manufacturing a piezoelectric element. A method of manufacturing a liquid ejecting head, comprising using the piezoelectric element manufactured by the manufacturing method according to claim 4.

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