JP5679636B2 - Liquid ejecting head and actuator device - Google Patents

Description

  The present invention relates to a liquid ejecting head, a liquid ejecting apparatus, and an actuator device.

  An actuator device used for a liquid ejecting head or the like is a piezoelectric element in which a piezoelectric layer made of a piezoelectric material exhibiting an electromechanical conversion function is sandwiched between two electrodes, and the piezoelectric layer is made of, for example, crystallized piezoelectric ceramics. It is configured.

  In the piezoelectric element, a first electrode film is formed on one surface side of a substrate (flow path forming substrate) by a sputtering method, and then a piezoelectric layer is formed on the first electrode by a sol-gel method or a MOD method, A second electrode is formed on the piezoelectric layer by a sputtering method, and then the piezoelectric layer and the second electrode are patterned to form a piezoelectric element. As the first electrode of this piezoelectric element, one using platinum is known (for example, see Patent Document 1).

JP 2007-173604 A

  The advantage of using platinum as the first electrode is that it does not lose conductivity even during high-temperature heat treatment when the piezoelectric precursor film is baked to form the piezoelectric layer. For example, the piezoelectric layer can be formed to have a desired crystal orientation. However, the use of platinum for the first electrode increases the cost of the piezoelectric element, and thus the liquid ejecting head and the liquid ejecting apparatus, which hinders the generalization of products.

  Such a problem is not limited to an actuator device used for an ink jet recording head, but also exists in an actuator device used for a liquid ejecting head that ejects another liquid, and is used for a device other than the liquid ejecting head. Also present in actuator devices.

The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid jet head及beauty Position actuator device having an actuator device which can reduce the cost without reducing the displacement characteristics.

The liquid ejecting head of the present invention includes a pressure generating chamber communicating with a nozzle opening for ejecting liquid, and a piezoelectric element that causes a pressure change in the pressure generating chamber, and the piezoelectric element includes a first electrode, A piezoelectric layer formed on the first electrode; and a second electrode formed on the opposite side of the piezoelectric layer from the first electrode, wherein the first electrode extends from the piezoelectric layer side. , Ri and chromium layer mainly composed of conductive oxide layer and a chromium oxide as a main component iridium name are laminated in this order, the piezoelectric layer is formed by epitaxial growth on the first electrode It is lead zirconate titanate, preferentially oriented in the (100) plane, and a platinum layer is provided thinner than the chromium layer in the upper layer or lower layer of the chromium layer . In the liquid ejecting head of the present invention, the chrome layer is formed instead of the platinum layer in the piezoelectric element, so that the manufacturing cost of the liquid ejecting head itself can be suppressed. In this case, by using chromium instead of other conductive materials, it is possible to maintain the same performance as a conventional piezoelectric element having a platinum layer formed, and the displacement characteristics are not deteriorated. Further, the conductive oxide layer contains iridium oxide as a main component in order to prevent the components of the piezoelectric layer from diffusing to the first electrode side. Furthermore, it is mentioned that the piezoelectric layer is lead zirconate titanate formed by epitaxial growth on the first electrode and is preferentially oriented on the (100) plane. Note that the preferential orientation refers to a state in which the orientation direction of the crystal is not disordered and a specific crystal plane is oriented in a substantially constant direction.

According to another aspect of the invention, a liquid ejecting apparatus includes the liquid ejecting head. By providing a liquid jet head in which the cost is reduced by providing a piezoelectric element in which a platinum layer is provided thinner than the chromium layer on the upper layer or the lower layer of the chromium layer, the manufacturing cost of the liquid jet apparatus is also suppressed. It is possible. In this case, by using chromium instead of other conductive materials, it is possible to maintain the same performance as a conventional piezoelectric element having a platinum layer formed, and the displacement characteristics are not deteriorated.

The actuator device of the present invention includes a first electrode, a piezoelectric layer formed on the first electrode, and a second electrode formed on the opposite side of the piezoelectric layer from the first electrode. the first electrode, the piezoelectric layer side, Ri and chromium layer mainly composed of conductive oxide layer and a chromium oxide as a main component iridium name are laminated in this order, the piezoelectric layer Is lead zirconate titanate formed by epitaxial growth on the first electrode, and is preferentially oriented on the (100) plane, and a platinum layer is formed above or below the chromium layer than the chromium layer. It is characterized by being thinly provided . In the actuator device of the present invention, the production cost can be suppressed by providing a platinum layer thinner than the chromium layer in the upper or lower layer of the chromium layer in the piezoelectric element. In this case, by using chromium instead of other conductive materials, it is possible to maintain the same performance as the conventional piezoelectric element having the platinum layer formed, so the actuator device of the present invention is the same as the conventional one. Displacement characteristics are provided.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the recording head according to the first embodiment of the invention. 2A and 2B are a plan view and a cross-sectional view of the recording head according to Embodiment 1 of the invention. FIG. 3 is an enlarged cross-sectional view of a main part of the recording head according to Embodiment 1 of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment of the invention. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment of the present invention.

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

  As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate, and an elastic film 50 made of silicon dioxide 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. In addition, 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 supply path 14 and a communication path 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.

  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. As the insulator film 55, zirconium oxide is used in this embodiment. Furthermore, the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are laminated on the insulator film 55 by a process that will be described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 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 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. Here, the piezoelectric element 300 that is displaced by driving is 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 vibration plate. However, the present invention is not limited to this. For example, the elastic film 50 and the insulator film 55 are provided. Instead, only the first electrode 60 may act as a diaphragm. Further, the piezoelectric element 300 itself may substantially serve as a diaphragm.

The piezoelectric layer 70 is formed on the first electrode 60 and is made of a piezoelectric material that exhibits an electromechanical conversion action. The piezoelectric layer 70 is formed by laminating piezoelectric films that are crystal films having a perovskite structure, and includes at least Pb, Ti, and Zr. As a material of the piezoelectric layer 70, for example, a piezoelectric material (ferroelectric material) such as lead zirconate titanate (PZT) or a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide is added thereto. Are suitable, such as lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O ₃ ) or lead magnesium titanate zirconate (Pb (Zr, Ti) (Mg, Nb) O ₃ ). ) Etc. can also be used. In this embodiment, the piezoelectric layer 70 uses lead zirconate titanate and is preferentially oriented in the (100) plane. The piezoelectric layer 70 is formed to a thickness (0.5 to 5 μm) that suppresses the thickness to the extent that cracks do not occur in the manufacturing process and exhibits sufficient displacement characteristics.

As shown in FIG. 3 in the present embodiment, the first electrode 60 includes a chromium layer 61 mainly composed of chromium and a conductive oxide (iridium oxide (IrO _{x in} this embodiment)) from the insulator film 55 side. ) And a conductive oxide layer 62 containing as a main component. A crystal seed layer 63 mainly composed of titanium oxide (TiO _x ) is provided between the first electrode 60 and the piezoelectric layer 70. “Main component” means a metal element having the highest intensity detected in each layer, and the state of the main component contained in each layer is not particularly limited, and each is a single metal state, an alloy state, an intermetallic compound. Or the state of other compounds such as metal oxides.

The chromium layer 61 is mainly composed of chromium, which is lower in cost than platinum. That is, in the present embodiment, the first electrode 60 having substantially the same performance as that of the first electrode using conventional platinum is formed using chromium instead of platinum. Costs can be suppressed. For example, regarding electrical conductivity, the electrical conductivity of chromium is 7.7 × 10 ⁶ S / m, and the electrical conductivity of platinum is 9.4 × 10 ⁶ S / m. . Further, since chromium is excellent in heat resistance like platinum, even if a piezoelectric layer is formed by forming and firing a piezoelectric precursor film on the first electrode 60, the conductivity is not easily lowered. . Moreover, since the Young's modulus of chromium is 250 GPa and the Young's modulus of platinum is 150 GPa, the displacement characteristics of the piezoelectric element 300 can be made substantially equal even when chromium is used.

  Further, when chromium is used, a piezoelectric layer 70 having a desired crystal orientation, that is, preferentially oriented in the (100) plane, can be formed on the first electrode 60 in the same manner as platinum. This point will be described in detail below.

  First, a conventional first electrode using platinum will be described. Conventionally, a platinum layer containing platinum as a main component / conductive oxide layer / crystal seed layer / piezoelectric layer is laminated on the diaphragm in this order. The piezoelectric layer is formed by epitaxial growth. Generally, in epitaxial growth, the preferential orientation of the film is determined by the underlayer. Conventionally, since the conductive oxide layer is sufficiently thin, there is no influence on the crystal orientation of the piezoelectric layer, and the piezoelectric layer obtained by epitaxial growth has priority over the (100) plane by the platinum layer and the crystal seed layer as the underlayer. An oriented product was obtained. That is, the platinum layer is preferentially oriented in the (111) plane in the face-centered cubic structure crystal by natural orientation, and the crystal seed layer (Ti) formed on the platinum layer is in the (200) plane in the hexagonal close-packed structure. Priority orientation. The crystal orientation of such a crystal seed layer can cancel the crystal orientation of the platinum layer, whereby the piezoelectric layer formed on the crystal seed layer is free-growing and has priority over the perovskite structure (100) plane. It was oriented.

  In contrast, in the present embodiment, unlike the platinum layer, the chromium layer 61 preferentially oriented in the (100) plane is used, but the piezoelectric layer 70 formed on the crystal seed layer 63 grows freely. (100) plane can be preferentially oriented. This is due to the following reason. Chromium has a body-centered cubic lattice and a lattice constant of 2.879Å, and is preferentially oriented in the (100) plane by natural orientation. Since the crystal lattice of platinum is a face-centered cubic lattice and the lattice constant is 3.9Å, considering the fact that it is a face-centered cubic lattice, the interatomic distance in platinum is 3.9 × (1 / √ 2) = 2.757 mm. Then, since the lattice spacing of chromium and the interatomic distance of platinum are very close (the lattice mismatch value between the interatomic distance of platinum and the lattice constant of chromium is 4.4%), the first electrode 60 is thus Even when the chromium layer 61 is provided, the crystal seed layer 63 formed on the chromium layer 61 can cancel the orientation of the chromium layer 61. Therefore, the piezoelectric layer 70 epitaxially grown on the crystal seed layer 63 can be preferentially oriented in the (100) plane as in the conventional piezoelectric layer.

  Here, the chromium layer 61 is easy to oxidize, and if chromium is oxidized, the conductivity is lost. Therefore, in the present embodiment, a conductive oxide layer 62 is formed on the chromium layer 61 in order to suppress diffusion of oxygen from above. The conductive oxide layer 62 functions not only as an oxygen diffusion preventing layer but also as a lead diffusion preventing layer, and is a component constituting the piezoelectric layer 70 by high-temperature heat treatment when the piezoelectric layer 70 is formed. This is to prevent the lead, which is, from diffusing into the first electrode 60, particularly the insulator film 55, the elastic film 50, and the flow path forming substrate 10 that are the foundation of the first electrode 60. As described above, since the chromium layer 61 is formed between the conductive oxide layer 62 and the insulator film 55 made of oxide, it is possible to suppress the diffusion and oxidation of oxygen in the chromium layer 61. Note that an oxide film is formed on the surface of the chromium layer 61, which functions to suppress oxygen permeation.

  Further, as the material of the conductive oxide layer 62, it is preferable to use iridium oxide as mentioned in this embodiment, but in addition to this, palladium oxide, rhodium oxide, ruthenium oxide, osmium oxide, or the like is used. Can do.

  The thickness of each layer is 20 to 150 nm for the chromium layer 61, 5 to 20 nm for the conductive oxide layer 62, and 1 to 8 nm for the crystal seed layer 63. When the thickness of each film is within this range, it is possible to obtain the piezoelectric layer 70 having a desired characteristic, that is, a high displacement characteristic that is preferentially oriented in the (100) plane.

  Returning to FIGS. 1 and 2, 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 extends to the insulator film 55. A lead electrode 90 made of gold (Au) or the like is connected.

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, that is, on the first electrode 60, the insulator film 55, and the lead electrode 90, there is a reservoir portion 31 that constitutes at least a part of the reservoir 100. The protective substrate 30 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 communication portion 13 of the flow path forming substrate 10 is formed. The reservoir 100 is configured as a common ink chamber for the pressure generating chambers 12. 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. The piezoelectric element holding part 32 only needs to have a space that does not hinder the movement of the piezoelectric element 300, and the space may be sealed or unsealed.

  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 drive circuit 120 for driving the piezoelectric elements 300 arranged side by side is fixed on the protective substrate 30. 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.

  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. 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 of the present embodiment, ink is taken in from an ink introduction port connected to an external ink supply means (not shown), and the interior from the reservoir 100 to the nozzle opening 21 is filled with ink, and then from the drive circuit 120. In accordance with the recording signal, 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 layer 70 are moved. By deflecting and deforming, the pressure in each pressure generating chamber 12 is increased and ink droplets are ejected from the nozzle openings 21.

(Inkjet recording head manufacturing method)
A method for manufacturing the ink jet recording head of this embodiment will be described with reference to FIGS. 4 to 8 are cross-sectional views showing a method for manufacturing the ink jet recording head of this embodiment.

First, as shown in FIG. 4A, an oxide film 51 constituting the elastic film 50 is formed on the surface of a wafer 110 for flow path forming substrate 110, which is a silicon wafer and in which a plurality of flow path forming substrates 10 are integrally formed. To do. The method for forming the oxide film 51 is not particularly limited. For example, the oxide film 51 made of silicon dioxide (SiO ₂ ) may be formed by thermally oxidizing the flow path forming substrate wafer 110 in a diffusion furnace or the like.

4B, on the elastic film 50 (oxide film 51), an oxide film made of a material different from that of the elastic film 50, in this embodiment, an insulator film made of zirconium oxide (ZrO ₂ ). 55 is formed. A method for forming the insulator film 55 is not particularly limited. For example, after forming a zirconium (Zr) layer on the elastic film 50 (oxide film 51), the insulator film 55 is thermally oxidized in a diffusion furnace at 500 to 1200 ° C., for example. Thus, the insulator film 55 made of zirconium oxide (ZrO ₂ ) may be formed.

  Next, as shown in FIG. 4C, which is a partially enlarged view, a chromium film 65, a conductor film 66, and a crystal seed film 67 are sequentially stacked on the insulator film 55. Each of the films 65 to 67 formed on the insulator film 55 is preferably sputtered continuously in the same sputtering apparatus. For example, in the DC magnetron sputtering method, only the target is changed without continuously releasing the inside of the film forming apparatus from the vacuum state, and the film is continuously formed. Thus, the chromium layer 61, the conductive oxide layer 62, and the crystal seed layer 63 having a desired crystal orientation are formed by continuously sputtering and forming a film without changing the film forming atmosphere in the DC magnetron sputtering apparatus. Can be obtained.

  Specifically, first, a chromium film 65 is formed on the insulator film 55. Note that the chromium film 65 becomes a chromium layer 61 having an oxide film formed on the surface by being simultaneously heated when the piezoelectric layer 70 is formed by heating and baking in a later step.

  Next, a conductor film 66 made of iridium (Ir) is formed on the chromium film 65. The conductor film 66 becomes the conductive oxide layer 62 when the piezoelectric layer 70 is formed by heating and baking in a later step, and suppresses the oxidation of the chromium film 65, and at the same time, the piezoelectric layer. The lead which is a component of 70 is prevented from diffusing to the first electrode 60 side. In the present embodiment, the conductive oxide layer 62 (see FIG. 3) is formed to have a thickness of 10 nm. In the present embodiment, iridium is used as the material of the conductor film 66, but the conductor film material may be one selected from palladium, rhodium, ruthenium, and osmium.

Next, a crystal seed film 67 made of titanium is formed on the conductor film 66. By providing the crystal seed film 67 on the conductor film 66 in this manner, the piezoelectric layer 70 is formed when the piezoelectric layer 70 is formed on the conductor film 66 via the crystal seed film 67 in a later step. Can be controlled to (100), and a piezoelectric layer 70 suitable as an electromechanical transducer can be obtained. The crystal seed film 67 functions as a seed for promoting crystallization when the piezoelectric layer 70 is crystallized, and a part of the crystal seed film 67 diffuses into the piezoelectric layer 70 after the piezoelectric layer 70 is fired. The first electrode 60 is thermally oxidized and partially remains (crystal seed layer 63). In the present embodiment, titanium (Ti) is used as the crystal seed film 67. However, when the piezoelectric layer 70 is formed in a later step, the crystal seed film 67 is a crystal of the piezoelectric layer 70. For example, titanium oxide (TiO ₂ ) may be used as the crystal seed film 67. Such a crystal seed film 67 can be formed by, for example, a sputtering method such as a DC magnetron sputtering method, a CVD method (chemical vapor deposition method), or the like.

  Next, a piezoelectric layer 70 made of lead zirconate titanate (PZT) is formed. Here, in this embodiment, a so-called sol in which an organometallic compound is dissolved and dispersed 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 a gel method. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or a sputtering method may be used.

  A specific method will be described below. First, as shown in FIG. 5A, a piezoelectric precursor film 71 is formed on the first electrode 60. That is, a sol (solution) containing a metal organic compound is applied onto the flow path forming substrate 10 on which the first electrode 60 is formed (application process). Next, the piezoelectric precursor film 71 is heated to a predetermined temperature and dried for a predetermined time (drying step). For example, in the present embodiment, the piezoelectric precursor film 71 can be dried by holding at 150 to 180 ° C. for 3 to 10 minutes.

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). For example, in this embodiment, the piezoelectric precursor film 71 is degreased by heating to a temperature of about 300 to 400 ° C. and holding for about 3 to 10 minutes. Here, degreasing refers, the organic components contained in the piezoelectric precursor film 71, for _example, is to be detached as _{NO 2, CO 2, H 2} O or the like.

  Next, the piezoelectric precursor film 71 is crystallized by being heated to a predetermined temperature by an infrared heating device and held for a certain period of time to form a piezoelectric film 72 (firing step).

  In addition, in the drying step and the degreasing step described above, by using the infrared heating device used in the firing step, the type of device to be used can be reduced and the manufacturing cost can be reduced, but in the drying step and the degreasing step, A device other than the infrared heating device, for example, a hot plate may be used.

  The chromium film 65, the conductor film 66, and the crystal seed film 67 are also heated at the same time by performing a baking process for forming the piezoelectric film 72 by heating and baking the piezoelectric precursor film 71. By this firing step, the chromium film 65, the conductor film 66, and the crystal seed film 67 become the chromium layer 61, the conductive oxide layer 62, and the crystal seed layer 63, respectively, and the first electrode 60 is formed. Of course, the crystal seed layer 63 may be entirely diffused in the piezoelectric precursor film 71.

  Next, as shown in FIG. 5B, when the first piezoelectric film 72 is formed on the first electrode 60, the first electrode 60, the crystal seed layer 63, and the first piezoelectric film. 72 is simultaneously patterned. The patterning of the first electrode 60 and the first piezoelectric film 72 can be performed by dry etching such as ion milling, for example.

  Next, as shown in FIG. 5C, after patterning the first-layer piezoelectric film 72 and the first electrode 60, the piezoelectric body comprising the above-described coating process, drying process, degreasing process, and firing process. By repeating the film formation step a plurality of times, a piezoelectric layer 70 composed of a plurality of layers of piezoelectric films 72 is formed.

  Next, as shown in FIG. 6A, after the second electrode 80 made of, for example, iridium (Ir) is formed on the piezoelectric layer 70, the piezoelectric layer is formed as shown in FIG. 6B. The body layer 70 and the second electrode 80 are patterned in a region facing each pressure generating chamber 12 to form the piezoelectric element 300. Examples of the patterning 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. 6C, the 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 made of, for example, a resist or the like. It is formed by patterning each piezoelectric element 300 via a mask pattern (not shown).

  Next, as shown in FIG. 7A, a protective substrate wafer 130 that is a silicon wafer and serves as a plurality of protective substrates 30 is disposed on the piezoelectric element 300 side of the flow path forming substrate wafer 110 via an adhesive 35. Join.

  Next, as shown in FIG. 7B, the flow path forming substrate wafer 110 is thinned to a predetermined thickness.

  Next, as shown in FIG. 7C, 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. 8, the flow path forming substrate wafer 110 is subjected to anisotropic etching (wet etching) using an alkaline solution such as KOH through the mask film 52, whereby a pressure corresponding to the piezoelectric element 300 is obtained. A generation chamber 12, a communication portion 13, an ink supply path 14, a communication path 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 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 I 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 as shown in FIG.

  As described above, in the present embodiment, the first electrode 60 is formed on the first electrode 60 while suppressing the cost by forming the chromium layer 61 using chromium without using platinum. Then, the piezoelectric layer 70 can be formed. In this case, chromium is easily oxidized, but the entire chromium layer 61 does not become chromium oxide because the conductive oxide layer 62 that functions as a lead diffusion preventing layer is formed.

(Inkjet recording device)
These ink jet recording heads I constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are mounted on an ink jet recording apparatus. FIG. 9 is a schematic view showing an example of the ink jet recording apparatus.

  In the ink jet recording apparatus II shown in FIG. 9, the recording head units 1A and 1B having the ink jet recording head I are detachably provided with cartridges 2A and 2B constituting the ink supply means, and the recording head units 1A and 1B. Is mounted on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the fundamental structure of this invention is not limited to what was mentioned above. For example, a platinum layer may be provided thinner than the chromium layer 61 in the upper layer or the lower layer of the chromium layer 61 in order to improve conductivity.

  In the embodiment described above, a silicon single crystal substrate is exemplified as the flow path forming substrate 10, but the present invention is not particularly limited thereto, and for example, a material such as an SOI substrate or glass may be used.

  In the above-described embodiment, 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 the liquid ejecting ejects a liquid other than ink. Of course, it can also be applied to the 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.

  In the ink jet recording apparatus II described above, the ink jet recording head I (head units 1A, 1B) is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line recording apparatus in which the ink jet recording head I is fixed and printing is performed simply by moving the recording sheet S such as paper in the sub-scanning direction.

  The present invention is not limited to an actuator device mounted on a liquid ejecting head typified by an ink jet recording head, and can also be applied to an actuator device mounted on another device.

  I ink jet recording head (liquid ejecting head), II ink jet recording apparatus (liquid ejecting apparatus), 10 flow path forming substrate, 12 pressure generating chamber, 13 communicating portion, 14 ink supply path, 15 communicating path, 20 nozzle plate, 21 Nozzle opening, 30 Protection substrate, 31 Reservoir part, 40 Compliance substrate, 50 Elastic film, 55 Insulator film, 60 First electrode, 61 Chromium layer, 62 Conductive oxide layer, 63 Crystal seed layer, 70 Piezoelectric layer 72 piezoelectric film, 80 second electrode, 90 lead electrode, 100 reservoir, 120 driving circuit, 300 piezoelectric element

Claims (2)

A pressure generation chamber communicating with a nozzle opening for ejecting liquid; and a piezoelectric element that causes a pressure change in the pressure generation chamber,
The piezoelectric element includes a first electrode, a piezoelectric layer formed on the first electrode, and a second electrode formed on the opposite side of the piezoelectric layer from the first electrode,
The first electrode is formed by laminating a conductive oxide layer mainly composed of iridium oxide and a chromium layer mainly composed of chromium in this order from the piezoelectric layer side.
The piezoelectric layer is lead zirconate titanate formed by epitaxial growth on the first electrode, and is preferentially oriented in the (100) plane;
The liquid jet head according to claim 1, wherein a platinum layer is provided thinner than the chromium layer on an upper layer or a lower layer of the chromium layer. A first electrode; a piezoelectric layer formed on the first electrode; and a second electrode formed on the opposite side of the piezoelectric layer from the first electrode;
The first electrode is formed by laminating a conductive oxide layer mainly composed of iridium oxide and a chromium layer mainly composed of chromium in this order from the piezoelectric layer side.
The piezoelectric layer is lead zirconate titanate formed by epitaxial growth on the first electrode, and is preferentially oriented in the (100) plane;
An actuator device, wherein a platinum layer is provided thinner than the chromium layer on the upper layer or the lower layer of the chromium layer.

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