JP6064352B2 - Method for manufacturing liquid jet head, method for manufacturing liquid jet device, and method for manufacturing piezoelectric element - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid ejecting head having a piezoelectric element including a diaphragm including a zirconium oxide layer, a method for manufacturing a liquid ejecting apparatus, and a method for manufacturing a piezoelectric element.

As a piezoelectric element used for a piezoelectric device, there is a piezoelectric material exhibiting an electromechanical conversion function, for example, a structure in which a ferroelectric layer made of a crystallized dielectric material is sandwiched between two electrodes. A piezoelectric element is known in which a zirconium oxide (ZrO ₂ ) layer is provided as a part of a diaphragm.

  And the method of forming a zirconium oxide layer by forming a metallic zirconium layer by sputtering etc. and thermally oxidizing the metallic zirconium layer is proposed (for example, refer to patent documents 1).

JP 2005-294438 A

  However, in the actuator device having such a structure, the adhesion force between the zirconium oxide layer and the electrode provided thereon and the adhesion force between the zirconium oxide layer and the underlying silicon oxide film are not sufficient. Has led to a decline.

  Such a problem exists not only in an actuator device mounted on a liquid ejecting head such as an ink jet recording head but also in an actuator device mounted on another device.

  In view of such circumstances, the present invention provides a method for manufacturing a liquid ejecting head having a zirconium oxide layer excellent in adhesion to a base layer and electrodes of a diaphragm, a method for manufacturing a liquid ejecting apparatus, and a method for manufacturing a piezoelectric element. The purpose is to do.

An aspect of the present invention for solving the above-described problem is a method of manufacturing a liquid jet head including a piezoelectric element having a piezoelectric layer and an electrode provided on the piezoelectric layer above the zirconium oxide layer, When forming the zirconium layer, the method includes a step of applying a precursor solution and a step of crystallizing the coating film, and the precursor solution is made of a metal alkoxide containing Zr and a metal carboxylate containing Zr. at least one selected from the group, 1-1.2 mol in the case of the metal alkoxide, if the metal carboxylate in the method of manufacturing a liquid jet head, characterized in that it comprises 1- 1.2 mole is there.
According to the present invention, the adhesion between the zirconium oxide layer and the underlayer can be improved, and a highly durable liquid jet head can be realized.
Here, it is preferable that the precursor solution further contains polyethylene glycol.
According to another aspect of the invention, there is provided a method of manufacturing a liquid ejecting apparatus including a step of manufacturing a liquid ejecting head by the method of the above aspect.
Furthermore, another aspect of the present invention is a method for manufacturing a piezoelectric element having a piezoelectric layer and an electrode provided on the piezoelectric layer above the zirconium oxide layer, wherein the zirconium oxide layer is formed. And a step of applying the precursor solution and a step of crystallizing the coating film,
When the precursor solution is at least one selected from the group consisting of a metal alkoxide containing Zr and a metal carboxylate containing Zr, in the case of the metal alkoxide, 1-1.2 mol, of the metal carboxylate In the case of the piezoelectric element manufacturing method, it includes 1-1.2 mol.
Here, it is preferable that the precursor solution further contains polyethylene glycol.
Yet another embodiment is a method of manufacturing a liquid jet head including a piezoelectric element having a piezoelectric layer and an electrode provided on the piezoelectric layer above the zirconium oxide layer, wherein the zirconium oxide layer is formed. In this case, the liquid jet head manufacturing method includes a step of coating the precursor solution and a step of crystallizing the coating film.

  Here, the precursor solution preferably contains at least one selected from the group consisting of a metal alkoxide containing Zr and a metal carboxylate containing Zr. According to this, a zirconium oxide layer can be formed more reliably and adhesiveness can be improved.

Also, other embodiments are the method of manufacturing a liquid-jet apparatus characterized by including a step of manufacturing a liquid jet head by the method for producing the liquid ejecting head.
According to the present invention, the adhesion between the zirconium oxide layer and the underlayer can be improved, and a highly durable liquid ejecting apparatus can be realized.

Also, other embodiments, over the zirconium oxide layer, a method for manufacturing a piezoelectric element comprising an electrode provided on the piezoelectric layer and the piezoelectric collector layer, when forming the zirconium oxide layer, The method of manufacturing a piezoelectric element includes a step of applying a precursor solution and a step of crystallizing a coating film.
According to the present invention, the adhesion between the zirconium oxide layer and the underlayer can be improved, and a highly durable piezoelectric element can be realized.

Also, other embodiments, the precursor solution is in the method for manufacturing a piezoelectric element, which comprises at least one selected from the group consisting of metal carboxylate containing a metal alkoxide and Zr containing Zr .
According to the present invention, the zirconium oxide layer can be more reliably formed, and the adhesion with the base layer can be improved.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the recording head according to the first embodiment. FIG. 3 is a plan view of a main part of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment taken along line AA ′. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing a schematic configuration of an ink jet recording head which is an example of a liquid ejecting head having an actuator device according to Embodiment 1 of the present invention, and FIG. 2 is a plan view of a main part of the ink jet recording head. FIG. 3 is a cross-sectional view taken along line AA ′ of FIG.

As shown in the figure, the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110) in the present embodiment, and one surface thereof is composed of silicon dioxide (SiO ₂ ) previously formed by thermal oxidation. An elastic film 50 having a thickness of 0.5 to 2 μm is formed. In the flow path forming substrate 10, a plurality of pressure generating chambers 12 partitioned by the partition walls 11 are arranged in parallel in a first direction which is the width direction (short direction). In addition, a communication portion 13 is formed in the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10, that is, in a region outside the second direction orthogonal to the first direction, and the communication portion 13 and each pressure generation chamber 12 are formed. Are communicated via an ink supply path 14 and a communication path 15 provided for each pressure generating chamber 12. The communication part 13 communicates with a manifold part 31 of a protective substrate, which will be described later, and constitutes a part of a manifold that becomes a common ink chamber for each pressure generating chamber 12.

  The ink supply path 14 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and has a smaller cross-sectional area than the pressure generation chamber 12. For example, in this embodiment, the ink supply path 14 has a width smaller than the width of the pressure generation chamber 12 by narrowing the flow path on the pressure generation chamber 12 side between the manifold 100 and each pressure generation chamber 12 in the width direction. It is formed with. As described above, 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, each communication path 15 communicates with the side of the ink supply path 14 opposite to the pressure generation chamber 12 and has a larger cross-sectional area than the width direction (short direction) of the ink supply path 14.

  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 portion of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive or It is fixed by a heat welding film or the like. The nozzle plate 20 is made of glass ceramics, a silicon single crystal substrate, stainless steel, or the like.

On the other hand, an elastic film 50 made of silicon dioxide and having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. A zirconium oxide layer 55 made of zirconium oxide (ZrO ₂ ) and having a thickness of, for example, about 0.1 to 0.4 μm is laminated.

  The zirconium oxide layer 55 of this embodiment is formed by a liquid phase method as will be described later. That is, a precursor solution containing a metal alkoxide containing Zr or a metal carboxylate is applied onto the flow path forming substrate 10 having the elastic film 50, and then undergoes a drying step, a degreasing step, a temporary firing step, and a main firing step. It is formed. A detailed process of forming the zirconium oxide layer 55 will be described later. The zirconium oxide layer 55 formed by such a liquid phase method has high adhesion with the first electrode film 60 and the elastic film 50 as a base, and has excellent durability. Therefore, peeling of the first electrode film 60 and the elastic film 50 from the zirconium oxide layer 55 when the actuator device is driven can be prevented.

  On the zirconium oxide layer 55, a first electrode film 60 having a thickness of, for example, about 0.1 to 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 0.5 to 5 μm, and a thickness of For example, the piezoelectric element 300 including the second electrode film 80 of about 10 to 200 nm is formed.

  Here, the piezoelectric element 300 refers to a portion including the first electrode film 60, the piezoelectric layer 70, and the second electrode film 80. In general, one electrode 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 this case, 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 320. In the present embodiment, the first electrode film 60 is used as the common electrode of the piezoelectric element 300, and the second electrode film 80 is used as the 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. Absent. In any case, the piezoelectric active part 320 is formed for each pressure generating chamber 12. In the present embodiment, the first electrode film 60, the piezoelectric layer 70, and the second electrode film 80 are patterned so that the width on the second electrode film 80 side becomes narrow as shown in FIG. Has an inclined surface. In addition, here, the piezoelectric element 300 and a vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric element, but may be referred to as an actuator device. In the above-described example, the elastic film 50, the zirconium oxide layer 55, and the first electrode film 60 function as a diaphragm. However, the present invention is not limited to this, and without providing the elastic film 50, the zirconium oxide layer 55 and The first electrode film 60 may act as a diaphragm.

A first electrode film 60 is provided on the zirconium oxide layer 55. As the first electrode film 60 of this embodiment, various metals such as iridium (Ir), platinum (Pt), titanium (Ti), and tungsten (W), alloys thereof, and conductive materials such as LaNiO ₃ and SrRuO ₃ are used. A laminated electrode structure of a conductive composite oxide and various metal films is exemplified.

  In the present embodiment, as a material (piezoelectric material) of the piezoelectric layer 70 constituting the piezoelectric element 300, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT), niobium, nickel, A relaxor ferroelectric or the like to which a metal such as magnesium, bismuth or yttrium is added is used.

The piezoelectric layer 70 may be formed of a lead-free piezoelectric material. Examples of the lead-free piezoelectric material include bismuth ferrate ((BiFeO ₃ ), approximately “BFO”), barium titanate (( BaTiO ₃ ), approximately “BT”), potassium sodium niobate ((K, Na) (NbO ₃ ), approximately “KNN”), lithium potassium sodium niobate ((K, Na, Li) (NbO ₃ )), Potassium sodium tantalate lithium niobate ((K, Na, Li) (Nb, Ta) O ₃ ), potassium bismuth titanate ((Bi _1/2 K _1/2 ) TiO ₃ , approximately “BKT”), titanic acid Complex acid containing bismuth sodium ((Bi _1/2 Na _1/2 ) TiO ₃ , approximately “BNT”), bismuth manganate (BiMnO ₃ , approximately “BM”), bismuth, potassium, titanium and iron and having a perovskite structure Compound _{(x [(Bi x K 1} -x) TiO 3] - (1-x) [BiFeO 3], approximately "BKT-BF"), a composite oxide having a perovskite structure containing bismuth, iron, barium and titanium ((1-x) [BiFeO ₃ ] -x [BaTiO ₃ ], substantially “BFO-BT”), and those obtained by adding metals such as manganese, cobalt, and chromium ((1-x) [Bi (Fe _1-y M _y ) O ₃ ] -x [BaTiO ₃ ] (M is Mn, Co or Cr)) or the like is used.

  The second electrode film 80 may be any of various metals such as Ir, Pt, tungsten (W), tantalum (Ta), and molybdenum (Mo). These alloys and metal oxides such as iridium oxide. Things.

  Each second electrode film 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 extends to the zirconium oxide layer 55. For example, gold (Au) The lead electrode 90 which consists of etc. is connected. A voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90.

  Furthermore, on the flow path forming substrate 10 on which the piezoelectric element 300 is formed, the protective substrate 30 having the piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 in a region facing the piezoelectric element 300. Are joined by an adhesive 35. In addition, the piezoelectric element holding part 32 should just have a space of the grade which does not inhibit the motion of the piezoelectric element 300, and the said space may be sealed or may not be sealed.

  Further, the protective substrate 30 is provided with a manifold portion 31 in a region facing the communication portion 13, and the manifold portion 31 communicates with the communication portion 13 of the flow path forming substrate 10 as described above. A manifold 100 serving as a common ink chamber for the pressure generation chamber 12 is configured. 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 32 and the manifold portion 31 of the protective substrate 30, and the first electrode film is formed in the through hole 33. A portion of 60 and the tip of the lead electrode 90 are exposed.

  A driving circuit (not shown) for driving the piezoelectric element 300 is fixed on the protective substrate 30, and the driving circuit and the lead electrode 90 are electrically connected via a connection wiring made of a conductive wire such as a bonding wire. Connected.

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

  On the protective substrate 30, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded. Here, 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), and the sealing film 41 seals one surface of the manifold portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the area of the fixing plate 42 facing the manifold 100 is an opening 43 that is completely removed in the thickness direction, one surface of the manifold 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head of this embodiment, after taking ink from an external ink supply means (not shown) and filling the interior from the manifold 100 to the nozzle opening 21, the pressure is applied according to the recording signal from the drive circuit. A voltage is applied between each of the first electrode film 60 and the second electrode film 80 corresponding to the generation chamber 12, and the elastic film 50 made of the silicon oxide film 51, the zirconium oxide layer 55, the first electrode film 60, and the piezoelectric film. By flexing and deforming the body layer 70, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21. In the present embodiment, the first electrode film 60 or the elastic film 50 has a high adhesive force between the zirconium oxide layer 55 and the first electrode film 60 or the elastic film 50 is zirconium oxide even when the actuator device is driven to bend and deform. Since it does not peel from the layer 55, it is excellent in durability.

  Here, a method of manufacturing the ink jet recording head will be described with reference to FIGS. 4 to 8 are cross-sectional views in the longitudinal direction of the pressure generating chamber. First, as shown in FIG. 4A, a flow channel substrate wafer 110, which is a silicon wafer, is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon oxide film 51 constituting an elastic film 50 is formed on the surface thereof. To do.

  Subsequently, as shown in FIGS. 4B and 4C, a zirconium oxide layer 55 is formed on the silicon oxide film 51 by a liquid phase method. That is, as shown in FIG. 4B, a precursor solution of zirconium oxide is formed on the silicon oxide film 51 to form a precursor layer 56, and the precursor layer 56 is crystallized to form a zirconium oxide layer 55. (FIG. 4 (c)).

  The precursor solution of zirconium oxide used in such a liquid phase method contains a metal alkoxide containing Zr or a metal carboxylate containing Zr.

  Here, examples of the metal alkoxide include tetramethoxyzirconium, tetraethoxyzirconium, tetrapropoxyzirconium, tetraisopropoxyzirconium, tetrabutoxyzirconium, tetrahexylzirconium, tetrakis (2,4-pentanedionato) zirconium, and the like. Any alkoxide containing Zr is not particularly limited.

  Examples of metal carboxylates include zirconium acetate, zirconium propionate, tributoxyzirconium propionate, tetrakis (butanoic acid) zirconium, zirconium 2-ethylhexanoate, zirconium stearate, and the like. If it is, it will not specifically limit.

  The precursor solution is obtained by dissolving a metal alkoxide or a metal carboxylate in a solvent containing a carboxylic acid. The carboxylic acid is not particularly limited, and examples thereof include acetic acid, propionic acid, butanoic acid and the like, but it is preferable to use acetic acid.

  In addition, the precursor solution preferably contains a thickening agent because it can improve applicability and easily form a relatively thick film. As the thickener, for example, organic polymer compounds can be used, such as polyethylene glycol, polyvinyl acetate, hydroxypropyl cellulose, polyethylene glycol monomethyl ether, polypropylene glycol, polyvinyl alcohol, polyacrylic acid, polyamide, polyamic acid, acetyl. Although cellulose etc. are mentioned, it is preferable to use polyethyleneglycol.

The precursor solution described above is for the case where the zirconium oxide layer 55 is a ZrO ₂ layer. However, the zirconium oxide layer 55 may be an yttria stabilized zirconia (YSZ) layer, and this yttria stabilized zirconia (YSZ) may also be used. It is included. The precursor solution in the case of forming such an yttria-stabilized zirconia (YSZ) layer by a liquid phase method is obtained by adding a solution containing yttrium ions to a metal alkoxide or metal carboxylate containing Zr. Here, the solution containing yttrium ions is not particularly limited, and examples thereof include yttrium acetate solution, yttrium propionate solution, yttrium chloride solution, and yttrium nitrate solution.

A process for forming the zirconium oxide layer 55 will be described below.
First, a metal alkoxide or metal carboxylate and a thickening agent are added to the carboxylic acid, and then water (H ₂ O) is added, followed by heating and stirring at about 70 ° C. for about 2 hours to obtain a uniform transparent precursor. Get a body solution. This precursor solution is applied to the substrate at a rotational speed of 1400 rpm by a spin coating method (application process). Next, the solution applied to the substrate is heated to 160 ° C. to 200 ° C. and dried for about 5 minutes to obtain a dry film (drying step). And this degreasing | defatting is degreased by heating to 375 degreeC-415 degreeC and hold | maintaining for about 5 minutes (degreasing process). Here, degreasing refers, the organic components contained in the dry film, for example, is to be detached as _{NO 2, CO 2, H 2} O or the like. Next, the dried film is crystallized by heating to 750 ° C. to 850 ° C. and holding for about 3 minutes (pre-baking step), and further heating to 800 ° C. to 950 ° C. and holding for about 1 hour, A zirconium oxide layer 55 is formed (main firing step). Examples of the heating device used in the drying step, the degreasing step, the temporary firing step, and the main firing step include an RTA (Rapid Thermal Annealing) device that heats by irradiation with an infrared lamp, a hot plate, and the like.

  Here, in order to prevent the peeling of the first electrode film 60 and the elastic film 50 from the zirconium oxide layer 55, the adhesion between the first electrode film 60 and the elastic film 50 and the zirconium oxide layer 55 is improved. is necessary. In order to judge the adhesion, the scratch strength (mN) of the zirconium oxide layer is measured using a thin film scratch tester. If the scratch strength (mN) is 300 mN or more and no crack occurs, it is determined that the adhesion is high. In the liquid ejecting head, the resolution of the ejection port array for ejecting individual droplets has been increased every year to 300 dpi and 600 dpi, which requires a strength much higher than the scratch strength (150 mN) that seems to be sufficient in the past. Because it is done. The zirconium oxide layer 55 formed by the liquid phase method using the precursor solution has a high scratch strength (mN) of 300 mN or more and does not generate cracks, and thus has excellent durability.

  Further, it is desirable that the thickness of the zirconium oxide layer 55 formed by applying the precursor solution is thick. This is because the number of processes can be reduced and productivity can be improved. In the present embodiment, it was found that if tetrakis (2,4-pentanedionato) zirconium (IV) is used as the metal alkoxide, the zirconium oxide layer 55 can be made thicker.

  As described above, the film formation by the liquid phase method has an advantage that the environmental load is small compared to a gas phase method such as a sputtering method, is suitable for mass production, and can reduce the manufacturing cost. The greater the film thickness that can be formed by a single application, the greater the effect.

  After the formation of the zirconium oxide layer 55, for example, titanium (Ti), platinum (Pt), and iridium (Ir) are stacked on the zirconium oxide layer 55 by sputtering or the like, as shown in FIG. First electrode film 60 is formed.

  Next, a piezoelectric layer 70 made of lead zirconate titanate (PZT) or the like is formed on the first electrode film 60. Here, in the present embodiment, a so-called sol-gel in which a so-called sol obtained by dissolving and dispersing a metal organic substance in a solvent is applied, dried, gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed using the method. Moreover, it is not limited to the sol-gel method, For example, you may use the MOD (Metal-Organic Decomposition) method etc. Further, other sputtering methods may be used.

As a specific procedure for forming the piezoelectric layer 70, first, as shown in FIG. 5B, a piezoelectric precursor film 71 that is a PZT precursor film is formed on the first electrode film 60. That is, a sol (solution) containing a metal organic compound (lead zirconate titanate) is applied onto the flow path forming substrate 10 on which the first electrode film 60 is formed by a spin coat method or the like to form the piezoelectric precursor film 71. Form (application process). Next, the piezoelectric precursor film 71 is heated to a predetermined temperature and dried for a predetermined time (drying step). Next, the dried piezoelectric precursor film 71 is degreased by heating it to a predetermined temperature and holding it for a predetermined time (degreasing step). The degreasing referred to here is to release the organic component contained in the piezoelectric precursor film 71 as, for example, NO ₂ , CO ₂ , H ₂ O or the like.

  Next, as shown in FIG. 5C, the piezoelectric precursor film 71 is crystallized by being heated to a predetermined temperature and held for a predetermined time to form a piezoelectric film 72 (firing step). In addition, as a heating apparatus used by a drying process, a degreasing process, and a baking process, the RTA (Rapid Thermal Annealing) apparatus, a hotplate, etc. which heat by irradiation of an infrared lamp are mentioned, for example.

  Next, as shown in FIG. 6A, a resist 400 is formed on the piezoelectric film 72 and patterned into a predetermined shape. Next, as shown in FIG. 6B, the first electrode film 60 and the first piezoelectric film 72 are simultaneously patterned using the resist 400 as a mask so that the side surfaces thereof are inclined.

  Next, after the resist 400 is peeled off, the piezoelectric film forming process including the coating process, the drying process, the degreasing process, and the baking process described above is repeated a plurality of times to form the piezoelectric layer 70 including the plurality of piezoelectric films 72. Then, as shown in FIG. 6C, a piezoelectric layer 70 having a predetermined thickness composed of a plurality of layers of piezoelectric films 72 is formed. For example, the film thickness per one time of the sol is made very thin, and the film thickness of the entire piezoelectric layer 70 composed of a plurality of layers of piezoelectric films is set to about 1 to 3 μm. In the present embodiment, the piezoelectric film 72 is provided by being laminated. However, the film thickness of one layer of the piezoelectric film 72 may be increased to constitute only one layer. The piezoelectric layer 70 thus obtained is smooth and has no protruding region.

  After the piezoelectric layer 70 is formed, as shown in FIG. 7A, a second electrode film 80 made of iridium (Ir) is formed over the entire surface of the piezoelectric layer 70 by a sputtering method or the like. Patterning is performed in a region facing the pressure generation chamber 12 to form the piezoelectric element 300 including the first electrode film 60, the piezoelectric layer 70, and the second electrode film 80. The patterning of the piezoelectric layer 70 and the second electrode film 80 can be performed collectively by dry etching through a resist (not shown) formed in a predetermined shape. In such dry etching, when the side surface of the resist is inclined in advance, the piezoelectric layer 70 and the second electrode film 80 are patterned so that the width on the second electrode film 80 side is narrowed. Becomes an inclined surface.

  Next, as shown in FIG. 7B, a lead electrode 90 made of, for example, gold (Au) or the like is formed over the entire surface of the flow path forming substrate wafer 110, and then a mask pattern made of, for example, a resist or the like. Patterning is performed for each piezoelectric element 300 via (not shown).

  Next, as shown in FIG. 7C, a protective substrate wafer 130 that is a silicon wafer and serves as a plurality of protective substrates 30 is placed on the piezoelectric element 300 side of the flow path forming substrate wafer 110 via an adhesive 35. Join. In addition, since the protective substrate wafer 130 has a thickness of, for example, about several hundred μm, the rigidity of the flow path forming substrate wafer 110 is remarkably improved by bonding the protective substrate wafer 130.

  Next, as shown in FIG. 8A, the flow path forming substrate wafer 110 is thinned to a certain thickness. Further, for example, 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. 8B, the flow path forming substrate wafer 110 is anisotropically etched (wet etching) using an alkaline solution such as KOH through the mask film 52 to form 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. Then, after removing the silicon oxide film 51 on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130, the nozzle plate 20 having the nozzle openings 21 formed therein is bonded, and the protective substrate wafer is also formed. The compliance substrate 40 is bonded to 130, and the flow path forming substrate wafer 110 or the like is divided into the flow path forming substrate 10 or the like having a single chip size as shown in FIG. To do.

Hereinafter, it demonstrates further in detail based on an Example and a comparative example.
Example 1
Based on the above embodiment, the flow path forming substrate wafer 110 is thermally oxidized in a diffusion furnace at about 1100 ° C. to form a silicon oxide film 51 having a thickness of 1 μm, and is oxidized on the silicon oxide film 51 by a liquid phase method. A zirconium layer 55 was formed. Formation of the zirconium oxide layer 55 was performed in the following procedure. First, acetic acid 475.60 g (purity:> 99.7%, manufactured by Kanto Chemical Co., Inc.), zirconium acetate as a raw material of zirconium oxide (purity: 85-90%, manufactured by Sigma-Aldrich) (molecular weight 327.4) 1.0 mol and 317.06 g of polyethylene glycol (average molecular weight 600) as a thickener, and then add 317.06 g of water, followed by heating and stirring at 70 ° C. for about 2 hours. A precursor solution was obtained. Then, this precursor solution was apply | coated on the board | substrate at the rotation speed of 1400 rpm by the spin coat method (application | coating process).

  Next, the solution applied to the substrate was heated to 160 ° C. and dried for 5 minutes to obtain a dried film (drying step). The dried film was degreased by heating to 415 ° C. and holding for 5 minutes (degreasing step). Next, the dried film was crystallized by heating to 800 ° C. and holding for 3 minutes (temporary firing step), and further heated to 850 ° C. and held for 60 minutes to form the zirconium oxide layer 55 ( Main firing step). In addition, the RTA (Rapid Thermal Annealing) apparatus heated by irradiation of an infrared lamp was used as a heating apparatus used in the drying process, the degreasing process, and the pre-baking process. An electric furnace was used in the main firing step.

  The mass concentration calculated from the metal component contained in the precursor solution as zirconium oxide is 7.35% by mass.

(Example 2)
The conditions were the same as in Example 1 except that the zirconium acetate used in Example 1 was increased to 1.1 mol. The mass concentration calculated from the metal component contained in the precursor solution as zirconium oxide is 7.82% by mass.

(Example 3)
The conditions were the same as in Example 1 except that the zirconium acetate used in Example 1 was increased to 1.2 mol. In addition, it is 8.26 mass% when mass concentration is computed considering the metal component contained in a precursor solution as a zirconium oxide.

Example 4
The conditions were the same as in Example 1 except that the raw material for zirconium oxide used in Example 1 was tetrakis (2,4-pentanedionato) zirconium and the number of moles was 1.0 mol (487.66 g). . The mass concentration calculated from the metal component contained in the precursor solution as zirconium oxide is 7.71% by mass.

(Example 5)
The raw material of zirconium oxide used in Example 1 was tetrakis (2,4-pentanedionato) zirconium, and conditions were the same as in Example 1 except that the number of moles was 1.5 mol. The mass concentration calculated from the metal component contained in the precursor solution as zirconium oxide is 10.04% by mass.

(Example 6)
The conditions were the same as in Example 1 except that the raw material of zirconium oxide used in Example 1 was tetrakis (2,4-pentanedionato) zirconium and the number of moles was 2.0 mol. In addition, when mass concentration is calculated by using the metal component contained in the precursor solution as zirconium oxide, it is 11.82% by mass.

(Example 7)
What added the yttrium acetate to the zirconium acetate used in Example 1 was used as a precursor solution. The precursor solution was prepared by the following procedure. With acetic acid 475.60 g (purity:> 99.7%, manufactured by Kanto Chemical Co., Ltd.), zirconium acetate 521.26 g (purity: 85-90%, manufactured by Sigma-Aldrich) and thickener Add 317.06 g of polyethylene glycol (average molecular weight 600), add 317.06 g of water, add 24.1 g of yttrium acetate, and then heat and stir at 70 ° C. for about 2 hours. A precursor solution was obtained. In addition, it is 7.30 mass% when mass concentration is computed considering the metal component contained in a precursor solution as yttrium stabilization zirconia.

(Example 8)
The conditions were the same as in Example 1 except that the amount of zirconium acetate used as the raw material for zirconium oxide used in Example 1 was increased to 1.5 mol. In addition, it is 9.43 mass% when mass concentration is computed by making the metal component contained in a precursor solution into a zirconium oxide.

Example 9
The conditions were the same as in Example 1 except that zirconium acetate, which is the raw material for zirconium oxide used in Example 1, was increased to 2.0 mol. The mass concentration calculated from the metal component contained in the precursor solution as zirconium oxide is 10.99% by mass.

(Test example)
About each Example 1-9, the film thickness and scratch strength of the zirconium oxide layer 55 were measured.
The film thickness was calculated using a scanning electron microscope (SEM).
The scratch strength was evaluated by adhering a diamond indenter to a sample fixed on a table, gradually applying a load, and simultaneously moving the table at a constant speed to evaluate film adhesion.

  The raw material of zirconium oxide is zirconium acetate, and the number of moles is 1.0 mol (Example 1), 1.1 mol (Example 2), 1.2 mol (Example 3), 1.5 mol (Example 8). Table 1 shows the measurement results of the film thickness and scratch strength (mN) of the zirconium oxide layer 55 when formed as 2.0 mol (Example 9). In addition, the crack observation was performed about each zirconium oxide layer after this baking, and the scratch strength was measured only for the thing in which the crack did not generate | occur | produce. If no crack was generated and the scratch strength was 300 mN or more, the adhesion was high, and the determination was “good”.

  As a result, when the number of moles of zirconium acetate was 1.0 mole, 1.1 mole, and 1.2 mole, cracks did not occur and the scratch strength was 300 mN or more, but the mole number of zirconium acetate was 1. When increased to 5 mol and 2.0 mol, cracks occurred. However, even when the number of moles of zirconium acetate is increased to 1.5 moles and 2.0 moles, cracks can be prevented and a film having high scratch strength can be formed by changing drying and firing conditions. I think that the.

  However, under the film forming conditions described above, if the zirconium oxide layer 55 is formed with the number of moles of zirconium acetate being 1.0 mole, 1.1 mole, and 1.2 mole, the zirconium oxide layer 55 having excellent adhesion can be obtained. It was found that it can be formed. Such a piezoelectric element having the zirconium oxide layer 55 on the diaphragm, a liquid ejecting head including the piezoelectric element, and a liquid ejecting apparatus including the liquid ejecting head remove the elastic film 50 from the zirconium oxide layer 55. It can be prevented and has excellent durability.

  Table 2 shows the measurement results of the film thickness and scratch strength (mN) of the zirconium oxide layer 55 when the raw material of zirconium oxide was formed as tetrakis (2,4-pentanedionato) zirconium (Examples 4, 5, and 6). Show.

  As a result, it was found that the thickness of the zirconium oxide layer 55 can be increased when tetrakis (2,4-pentanedionato) zirconium is used as the raw material, compared with when zirconium acetate is used. In particular, it was found that when the raw material was 1.0 mol, the thickness of the zirconium oxide layer 55 could be increased by 42%.

  Here, when the mole number of tetrakis (2,4-pentanedionato) zirconium was 1.0 mole and 1.5 mole, cracks did not occur and the scratch strength was 300 mN or more. When increased to 0.0 mol, cracks occurred.

  Therefore, under the film formation conditions described above, if the zirconium oxide layer 55 is formed with the number of moles of tetrakis (2,4-pentanedionato) zirconium being 1.0 mole and 1.5 mole, the film thickness can be increased. Thus, it was found that the zirconium oxide layer 55 having excellent adhesion can be formed. Such a piezoelectric element having the zirconium oxide layer 55 on the diaphragm, a liquid ejecting head including the piezoelectric element, and a liquid ejecting apparatus including the liquid ejecting head remove the elastic film 50 from the zirconium oxide layer 55. It can be prevented and has excellent durability.

  Table 3 shows the measurement results of the film thickness and scratch strength (mN) of the zirconium oxide layer 55 when the zirconium oxide layer 55 is formed using yttrium-stabilized zirconia (Example 7).

  As a result, it was found that the scratch strength of the zirconium oxide layer 55 made of yttrium-stabilized zirconia formed by adding yttrium acetate was further increased as compared with the zirconium oxide layer 55 formed without adding yttrium acetate.

  Therefore, if the zirconium oxide layer 55 is yttrium-stabilized zirconia, the adhesion can be further improved. Such a piezoelectric element having the zirconium oxide layer 55 on the vibration plate, a liquid ejecting head including the piezoelectric element, and a liquid ejecting apparatus including the liquid ejecting head remove the elastic film 50 from the zirconium oxide layer 55. It can be prevented, and it is much more durable.

(Other embodiments)
Although one embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above-described first embodiment. For example, in Embodiment 1 described above, the silicon oxide layer and the zirconium oxide layer are provided in this order on the substrate. However, a substrate made of a metal oxide may be used, and the zirconium oxide layer may be provided directly on this substrate. Examples of the metal of the metal oxide include Mg. With such a configuration, the actuator device is excellent in adhesion between the first electrode film or substrate and the zirconium oxide layer. In addition, the board | substrate in which the one surface side provided with a zirconium oxide layer should just be a board | substrate which consists of metal oxides, for example, you may use the board | substrate with which the metal oxide film was provided in the side in which the zirconium oxide layer of the board | substrate body is provided.

  In the first 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 intended for 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, 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. Needless to say, the present invention can be applied not only to an actuator device mounted on a liquid jet head (such as an ink jet recording head) but also to an actuator device mounted on any device.

  DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Manifold part, 32 Piezoelectric element holding part, 40 Compliance board, 60 1st electrode Film, 70 piezoelectric layer, 80 second electrode film, 90 lead electrode, 100 manifold, 300 piezoelectric element, 320 piezoelectric active part

Claims (5)

A method of manufacturing a liquid jet head including a piezoelectric element having a piezoelectric layer and an electrode provided on the piezoelectric layer above the zirconium oxide layer,
When forming the zirconium oxide layer, including a step of applying a precursor solution, and a step of crystallizing the coating film,
When the precursor solution is at least one selected from the group consisting of a metal alkoxide containing Zr and a metal carboxylate containing Zr, in the case of the metal alkoxide, 1-1.2 mol, of the metal carboxylate In some cases, the method includes 1-1.2 mol.   The method of manufacturing a liquid jet head according to claim 1, wherein the precursor solution further contains polyethylene glycol.   A method for manufacturing a liquid ejecting apparatus, comprising: producing a liquid ejecting head by the manufacturing method according to claim 1. A method of manufacturing a piezoelectric element having a piezoelectric layer and an electrode provided on the piezoelectric layer above the zirconium oxide layer,
When forming the zirconium oxide layer, including a step of applying a precursor solution, and a step of crystallizing the coating film,
When the precursor solution is at least one selected from the group consisting of a metal alkoxide containing Zr and a metal carboxylate containing Zr, in the case of the metal alkoxide, 1-1.2 mol, of the metal carboxylate In the case, it includes 1-1.2 mol, A method for manufacturing a piezoelectric element.   The method for manufacturing a piezoelectric element according to claim 4, wherein the precursor solution further contains polyethylene glycol.

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