JP2008218879A - Piezoelectric element and manufacturing method thereof, liquid injection head, and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric element capable of improving the amount of displacement. <P>SOLUTION: The piezoelectric element 100 has: a substrate 1; a lower electrode 4 formed at an upper portion of the substrate 1; a buffer layer 22 that is formed at an upper portion of the lower electrode, is made of a metal oxide in a sodium chloride type structure, and is orientated in (100); a piezoelectric substrate layer 6 formed at the upper portion of the buffer layer 22 and made of a perovskite type oxide; and an upper electrode 7 formed at the upper portion of the piezoelectric substrate layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric element and a manufacturing method thereof, a liquid ejecting head, and a printer.

At present, the inkjet method is put into practical use as a high-definition and high-speed printing method. In order to eject ink droplets, a method using a piezoelectric element having a structure in which a piezoelectric layer is sandwiched between electrodes is useful. As a typical material of the piezoelectric layer, lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT) which is a perovskite oxide can be given (for example, see Patent Document 1).
JP 2001-223404 A

  The objective of this invention is providing the piezoelectric element which can aim at the improvement of displacement, and its manufacturing method. Another object of the present invention is to provide a liquid ejecting head and a printer having the piezoelectric element.

The piezoelectric element according to the present invention is
A substrate;
A lower electrode formed above the substrate;
A buffer layer formed above the lower electrode, made of a metal oxide with a sodium chloride structure and oriented in (100);
A piezoelectric layer formed above the buffer layer and made of a perovskite oxide;
An upper electrode formed above the piezoelectric layer.

  In the piezoelectric element according to the present invention, the piezoelectric layer is formed above the buffer layer made of a metal oxide having a sodium chloride structure and oriented in (100). Thereby, the piezoelectric layer can take over the orientation of the buffer layer and can be oriented to (100) in a pseudo cubic crystal display. Since the piezoelectric layer oriented in (100) exhibits excellent piezoelectricity, the amount of displacement of the piezoelectric layer and the like can be improved according to the piezoelectric element according to the present invention.

  In the description according to the present invention, the word “upward” refers to, for example, “another specific thing (hereinafter referred to as“ B ”) formed“ above ”a specific thing (hereinafter referred to as“ A ”)”. Etc. In the description of the present invention, in the case of this example, there are a case where B is directly formed on A and a case where B is formed on A via another. The word “above” is used as included.

  In the present invention, “oriented to (100)” means that all crystals are oriented to (100) and most crystals (for example, 90% or more) are oriented to (100). And the case where the remaining crystals not oriented to (100) are oriented to (111) or the like. That is, “orientation at (100)” can also be referred to as “priority orientation at (100)”.

In the piezoelectric element according to the present invention,
The piezoelectric layer may be oriented to (100) in a pseudo cubic display.

  In the present invention, “pseudo cubic” means a state in which the crystal structure is regarded as cubic.

In the piezoelectric element according to the present invention,
The crystal structure of the piezoelectric layer may be a monoclinic structure.

In the piezoelectric element according to the present invention,
The metal oxide may be magnesium oxide.

In the piezoelectric element according to the present invention,
The buffer layer may have a thickness of 3 nm or less.

In the piezoelectric element according to the present invention,
The perovskite oxide is represented by the general formula ABO ₃ ,
A includes lead (Pb),
The B may include zirconium (Zr) and titanium (Ti).

In the piezoelectric element according to the present invention,
The lower electrode may be made of a platinum group metal.

In the piezoelectric element according to the present invention,
The buffer layer is formed directly on the lower electrode;
The piezoelectric layer may be formed directly on the buffer layer.

  A liquid jet head according to the present invention includes the above-described piezoelectric element.

A liquid ejecting head according to the present invention includes:
A nozzle plate having a nozzle hole leading to the pressure chamber;
Including the above-described piezoelectric element formed above the nozzle plate,
The pressure chamber may be configured by an opening of a substrate included in the base body.

  A printer according to the present invention includes the above-described piezoelectric element.

The printer according to the present invention is
A head unit having the liquid jet head described above;
A head unit driving section for reciprocating the head unit;
And a control unit that controls the head unit and the head unit driving unit.

The method for manufacturing a piezoelectric element according to the present invention includes:
Forming a lower electrode above the substrate;
Forming a buffer layer oriented in (100) above the lower electrode so as to be composed of a metal oxide having a sodium chloride structure;
Forming a piezoelectric layer on the buffer layer so as to be made of a perovskite oxide;
Forming an upper electrode above the piezoelectric layer.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  1. First, the piezoelectric element 100 according to the present embodiment will be described. FIG. 1 is a cross-sectional view schematically showing the piezoelectric element 100.

  As shown in FIG. 1, the piezoelectric element 100 includes a base 1 and a drive unit 54. The base body 1 can include a substrate 52 and an elastic plate 55.

  As the substrate 52, for example, a (110) single crystal silicon substrate (plane orientation <110>) can be used. The substrate 52 has an opening 521. The opening 521 can be, for example, a pressure chamber of an ink jet recording head. The shape of the opening 521 is, for example, a rectangular parallelepiped having a width of 65 μm, a length of 1 mm, and a height of 80 μm.

The elastic plate 55 is formed on the substrate 52. The elastic plate 55 can include, for example, an etching stopper layer 30 and an elastic layer 32 formed on the etching stopper layer 30. The etching stopper layer 30 is made of, for example, silicon oxide (SiO ₂ ). The thickness of the etching stopper layer 30 is, for example, 1 μm. The elastic layer 32 is made of, for example, zirconium oxide (ZrO ₂ ). The thickness of the elastic layer 32 is, for example, 1 μm. Although not shown, the elastic plate 55 may not have the etching stopper layer 30.

  The drive unit 54 is formed on the elastic plate 55. The drive unit 54 can bend the elastic plate 55. The driving unit 54 includes a lower electrode 4 formed on the elastic plate 55 (more specifically, the elastic layer 32), a buffer layer 22 formed on the lower electrode 4, and a piezoelectric formed on the buffer layer 22. It has a body layer 6 and an upper electrode 7 formed on the piezoelectric layer 6. A main part of the drive unit 54 is formed, for example, on the opening 521, and a part (more specifically, the lower electrode 4) of the drive unit 54 is also formed on the substrate 52, for example.

  The lower electrode 4 is one electrode for applying a voltage to the piezoelectric layer 6. The lower electrode 4 can be made of, for example, a platinum group metal such as platinum (Pt) or iridium (Ir). As the lower electrode 4, for example, a single layer of a single platinum group metal or a laminate of a plurality of types of platinum group metals can be used. More specifically, as the lower electrode 4, for example, an electrode in which an iridium (Ir) layer (thickness 10 nm) is stacked on a platinum (Pt) layer (thickness 150 nm) can be used.

  The buffer layer 22 is made of a metal oxide having a sodium chloride (NaCl) type structure. Examples of the metal oxide include magnesium oxide (MgO). The buffer layer 22 is oriented in (100). Even if the lower electrode 4 which is the base has a plane orientation different from the (100) orientation (for example, (111) preferential orientation), the buffer layer 22 itself made of a metal oxide having a sodium chloride structure can be easily (100). Has the property of being oriented. This is presumably because the (100) plane of the sodium chloride structure has the lowest surface energy, and the (100) plane becomes the preferential orientation plane during film growth. This phenomenon is remarkably exhibited in magnesium oxide (MgO) having a sodium chloride structure. By forming the piezoelectric layer 6 directly on such a buffer layer 22, the orientation of the buffer layer 22 is succeeded, and the piezoelectric layer 6 oriented to (100) in a pseudo cubic display can be easily obtained. Obtainable. That is, the buffer layer 22 can have a function of controlling the crystal orientation of the piezoelectric layer 6. The thickness of the buffer layer 22 is preferably 3 nm or less. This is because when the buffer layer 22 is thicker than 3 nm, a desired amount of displacement of the elastic plate 55 cannot be obtained. This will be described in detail in a later experimental example.

The piezoelectric layer 6 is made of a perovskite-type oxide piezoelectric material. As the perovskite oxide, for example, represented by the general formula ABO ₃ , the A (element A: A site) contains lead (Pb), and the B (element B: B site) is zirconium (Zr). And those containing titanium (Ti). Examples of the perovskite oxide include lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT), lead zirconate titanate solid solution, and the like. Examples of the lead zirconate titanate solid solution include lead zirconate titanate niobate (Pb (Zr, Ti, Nb) O ₃ : PZTN). Further, an element other than lead (Pb), for example, lanthanum (La), barium (Ba), calcium (Ca), or the like may be further added to the A site.

For example, when the piezoelectric layer 6 is made of lead zirconate titanate (Pb (Zr _x Ti _1-x ) O ₃ ), the Zr composition x is, for example, 0.5. The thickness of the piezoelectric layer 6 is, for example, 1.0 μm.

  The piezoelectric layer 6 can be oriented to (100) in a pseudo cubic display. The crystal structure of the piezoelectric layer 6 is preferably a monoclinic structure. In the present invention, for example, “the crystal structure is a monoclinic structure” means that all crystals have a monoclinic structure, and most crystals (for example, 90% or more) have a monoclinic structure. And the case where the remaining crystal having no clinic structure has a tetragonal structure or the like. The polarization direction of the piezoelectric layer 6 is preferably an engineered domain arrangement that is inclined with respect to the direction perpendicular to the film surface (the thickness direction of the piezoelectric layer 6).

  The upper electrode 7 is the other electrode for applying a voltage to the piezoelectric layer 6. As the upper electrode 7, for example, an iridium (Ir) layer (thickness: 200 nm) can be used.

  The buffer layer 22, the piezoelectric layer 6, and the upper electrode 7 can constitute, for example, a columnar deposit (columnar portion) 5. The width of the columnar part 5 (the width of the lower surface of the buffer layer 22) is, for example, 50 μm, and the length of the columnar part 5 (the length of the lower surface of the buffer layer 22) is, for example, 1 mm.

  2. Next, a method for manufacturing the piezoelectric element 100 according to this embodiment will be described. FIG. 2 is a cross-sectional view schematically showing one manufacturing process of the piezoelectric element 100 of the present embodiment, and corresponds to the cross-sectional view shown in FIG.

  (1) First, the elastic plate 55 is formed on the substrate 52 as shown in FIG. Specifically, for example, the etching stopper layer 30 and the elastic layer 32 are formed in this order on the entire surface of the substrate 52. Thereby, the elastic plate 55 having the etching stopper layer 30 and the elastic layer 32 is formed. The etching stopper layer 30 is formed by, for example, a thermal oxidation method. The elastic layer 32 is formed by sputtering, for example.

  (2) Next, as shown in FIG. 2, the drive unit 54 is formed on the elastic plate 55. Specifically, first, the lower electrode 4, the buffer layer 22, the piezoelectric layer 6, and the upper electrode 7 are formed in this order on the entire surface of the elastic plate 55.

  The lower electrode 4 is formed by sputtering, for example.

  The buffer layer 22 is formed by sputtering, for example. The buffer layer 22 is naturally oriented to (100) and can be self-oriented. Therefore, the buffer layer 22 oriented in (100) can be obtained. The thickness immediately after the formation of the buffer layer 22 is preferably 3 nm or less. This is because when the buffer layer 22 is thicker than 3 nm, a desired amount of displacement of the elastic plate 55 cannot be obtained. This will be described in detail in a later experimental example. Further, the thickness immediately after the formation of the buffer layer 22 is, for example, 0.5 nm or more. If the thickness of the buffer layer 22 is less than 0.5 nm, it is considered that the function as the buffer layer cannot be achieved.

  The piezoelectric layer 6 is formed by, for example, a sol-gel method (solution method). Here, as an example, a case where the piezoelectric layer 6 made of PZT is formed will be described.

  First, a solution (piezoelectric material) in which an organometallic compound containing Pb, Zr, and Ti is dissolved in a solvent is applied to the entire surface of the buffer layer 22 by a spin coating method or the like. For example, the composition ratio (Zr: Ti) of Zr and Ti can be adjusted by changing the mixing ratio of the organometallic compound containing Zr and Ti in the solution. For example, the organometallic compound can be mixed so that Zr composition = Zr / (Zr + Ti) is 0.5. The composition of Pb can also be adjusted by changing the mixing ratio of the organometallic compound.

Next, the precursor layer of the piezoelectric layer 6 can be formed by performing heat treatment (drying step, degreasing step). It is preferable that the temperature of a drying process is 150 degreeC or more and 200 degrees C or less, for example. Moreover, it is preferable that the time of a drying process is 5 minutes or more, for example. In the degreasing step, the organic component remaining in the PZT precursor layer after the drying step can be thermally decomposed into NO ₂ , CO ₂ , H ₂ O, etc. and separated. The temperature of the degreasing process is, for example, about 300 ° C.

  When the precursor layer is formed, the precursor layer can be formed in a plurality of times without being formed once. Specifically, for example, the application, drying, and degreasing of the piezoelectric material can be repeated a plurality of times.

  Next, the precursor layer is fired. In the firing step, the PZT precursor layer can be crystallized by heating. The temperature of the firing step is, for example, 700 ° C. It is preferable that the time of a baking process is 5 minutes or more and 30 minutes or less, for example. The apparatus used for the firing step is not particularly limited, and a diffusion furnace, an RTA (Rapid Thermal Annealing) apparatus, or the like can be used. In addition, you may perform a baking process for every cycle of application | coating of a piezoelectric material, drying, and degreasing, for example.

  Further, for example, in this firing step, a part of the buffer layer 22 can be absorbed by, for example, the upper piezoelectric layer 6 or the lower electrode 4 below. As a result, the buffer layer 22 can be thinner than the thickness immediately after the buffer layer 22 is formed.

  Through the above steps, the piezoelectric layer 6 can be formed.

  The upper electrode 7 is formed by sputtering, for example.

  Next, for example, the upper electrode 7, the piezoelectric layer 6, and the buffer layer 22 can be patterned to form a columnar portion 5 having a desired shape. Thereafter, for example, the lower electrode 4 may be patterned. For patterning each layer, for example, a lithography technique and an etching technique can be used. The lower electrode 4, the buffer layer 22, the piezoelectric layer 6, and the upper electrode 7 can be patterned every time each layer is formed, or can be patterned all together when a plurality of layers are formed.

  Through the above steps, the drive unit 54 having the lower electrode 4, the buffer layer 22, the piezoelectric layer 6, and the upper electrode 7 is formed.

  (3) Next, as shown in FIG. 1, the substrate 52 is patterned to form openings 521. For the patterning of the substrate 52, for example, a lithography technique and an etching technique can be used. For example, the opening 521 is formed by etching a part of the substrate 52 so that the etching stopper layer 30 is exposed. In this etching step, the etching stopper layer 30 can function as an etching stopper. That is, when the substrate 52 is etched, the etching rate of the etching stopper layer 30 is slower than the etching rate of the substrate 52.

  Through the above steps, as shown in FIG. 1, the piezoelectric element 100 of the present embodiment is formed.

  3. In the piezoelectric element 100 of the present embodiment, the piezoelectric layer 6 is formed directly on the buffer layer 22 made of a metal oxide having a sodium chloride structure (for example, MgO) and oriented in (100). Thereby, the piezoelectric layer 6 can take over the orientation of the buffer layer 22 and can be oriented to (100) in a pseudo cubic display. Since the piezoelectric layer 6 oriented in (100) exhibits excellent piezoelectricity, the amount of displacement of the piezoelectric layer 6 and the elastic plate 55 can be improved according to the piezoelectric element 100 of the present embodiment. This has also been confirmed in experimental examples described later.

  Further, even if the buffer layer 22 of the piezoelectric element 100 of the present embodiment is formed directly on the lower electrode 4 made of, for example, polycrystalline platinum group metal, it can be naturally oriented to (100). Therefore, according to the piezoelectric element 100 of the present embodiment, a platinum group metal that is thermally stable even in a high-temperature process such as a baking process of a sol-gel method can be used as the material of the lower electrode 4, and When the buffer layer 22 is oriented to (100), the piezoelectric layer 6 can be oriented to (100).

  4). Next, a liquid ejecting head having the above-described piezoelectric element will be described. Here, a case where the liquid ejecting head 50 according to the present embodiment is an ink jet recording head will be described.

  FIG. 3 is an exploded perspective view schematically showing the liquid jet head 50 according to the present embodiment, which is shown upside down from a state in which it is normally used. In FIG. 3, for convenience, the drive unit 54 of the piezoelectric element 100 is shown in a simplified manner.

  The liquid ejecting head 50 includes, for example, the piezoelectric element 100 illustrated in FIG. 1 and a nozzle plate 51. The liquid ejecting head 50 can further include a housing 56.

  The nozzle plate 51 has a nozzle hole 511 that communicates with the pressure chamber 521. Ink is ejected from the nozzle hole 511. In the nozzle plate 51, for example, a number of nozzle holes 511 are provided in a line. The nozzle plate 51 is, for example, a rolled plate made of stainless steel (SUS). The nozzle plate 51 is fixed below the substrate 52 (upper in FIG. 3) in a state where it is normally used. The housing 56 can accommodate the nozzle plate 51 and the piezoelectric element 100. The housing 56 is formed using, for example, various resin materials, various metal materials, and the like.

  The substrate 52 of the piezoelectric element 100 partitions the space between the nozzle plate 51 and the elastic plate 55, so that a reservoir (liquid storage unit) 523, a supply port 524, and a plurality of cavities (pressure chambers) 521 are provided. Yes. The elastic plate 55 of the piezoelectric element 100 is provided with a through hole 531 penetrating in the thickness direction. The reservoir 523 temporarily stores ink supplied from the outside (for example, an ink cartridge) through the through hole 531. Ink is supplied from the reservoir 523 to each cavity 521 through the supply port 524.

  The cavity 521 includes an opening 521 of the substrate 52. One cavity 521 is provided for each nozzle hole 511. The cavity 521 has a variable volume due to the deformation of the elastic plate 55. This volume change causes ink to be ejected from the cavity 521.

  The drive unit 54 is electrically connected to a piezoelectric element drive circuit (not shown), and can be operated (vibrated or deformed) based on a signal from the piezoelectric element drive circuit. The elastic plate 55 is deformed by the deformation of the driving unit 54, and the internal pressure of the cavity 521 can be instantaneously increased.

  In the example described above, the case where the liquid ejecting head 50 is an ink jet recording head has been described. However, the liquid ejecting head of the present invention includes, for example, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used for forming an electrode such as an organic EL display and FED (surface emitting display), It can also be used as a bioorganic matter ejecting head used for biochip manufacture.

  5. Next, experimental examples will be described.

  In this experimental example, the liquid ejecting head 50 including the piezoelectric element 100 according to the present embodiment and the liquid ejecting head including the piezoelectric element according to the comparative example were manufactured.

  Magnesium oxide (MgO) was used as the buffer layer 22 of the piezoelectric element 100 according to the present embodiment. Further, the thickness of the buffer layer 22 was changed from 1.0 nm to 4.0 nm by 1.0 nm. Note that the thickness of the buffer layer 22 is a value immediately after the buffer layer 22 is formed, that is, before the piezoelectric layer 6 is formed.

  Further, the buffer layer was not provided in the piezoelectric element according to the comparative example. In other words, the thickness of the buffer layer of the piezoelectric element according to the comparative example was set to 0 nm.

X-ray diffraction measurement was performed on these experimental samples, and the degree of orientation of the (100) plane of the crystal of the piezoelectric layer was determined from the peak intensity. The peak intensity of the (100) plane is a, the peak intensity of the (111) plane is b, and the peak intensity of the (110) plane is c.
(100) Degree of orientation (%) = {a / (a + b + c)} × 100
It is. The display on each surface of the piezoelectric layer is a pseudo cubic display.

  Moreover, the voltage which changes from 0V to 35V was applied to the upper and lower electrodes with respect to these experimental samples, and the amount of displacement of the elastic plate was determined. A laser Doppler meter was used to measure the displacement of the elastic plate.

  Table 1 shows the degree of (100) orientation of the piezoelectric layer of each sample and the displacement of the elastic plate.

これらの測定結果から、本実施形態の圧電素子１００は、比較例の圧電素子に比べ、（１００）配向度および弾性板の変位量が大きいことが分かる。特に、バッファ層２２の厚さが１．０ｎｍ〜３．０ｎｍのサンプルでは、弾性板５５の変位量が４００ｎｍ以上という大きな値である。従って、本実施形態の圧電素子１００によれば、弾性板５５の変位量の向上、即ち、圧電体層６の変位量の向上を図ることができることが確認された。

From these measurement results, it can be seen that the piezoelectric element 100 of the present embodiment has a larger degree of (100) orientation and displacement of the elastic plate than the piezoelectric element of the comparative example. In particular, in a sample having a thickness of the buffer layer 22 of 1.0 nm to 3.0 nm, the displacement amount of the elastic plate 55 is a large value of 400 nm or more. Therefore, according to the piezoelectric element 100 of this embodiment, it was confirmed that the displacement amount of the elastic plate 55, that is, the displacement amount of the piezoelectric layer 6 can be improved.

  Further, as shown in Table 1, when the thickness of the buffer layer 22 according to the present embodiment exceeds 3.0 nm, the displacement amount of the elastic plate 55 falls below the desired value of 400 nm. This is because the buffer layer 22 remaining at the interface between the lower electrode 4 and the piezoelectric layer 6 becomes thick, and the influence thereof becomes strong. In this experimental example, magnesium oxide (MgO) constituting the buffer layer 22 is a paraelectric material, and its relative dielectric constant is 10 or less. On the other hand, the relative dielectric constant of PZT constituting the piezoelectric layer 6 in this experimental example is about 1000. Therefore, if the influence of the remaining buffer layer 22 becomes strong, a sufficient voltage cannot be applied to the piezoelectric layer 6 itself, and the amount of displacement decreases. Therefore, it is preferable that the thickness immediately after the formation of the buffer layer 22 is 3.0 nm or less. Thereby, the influence of the buffer layer 22 is reduced, a sufficient voltage can be applied to the piezoelectric layer 6 itself, and a large displacement can be obtained. If the thickness immediately after the formation of the buffer layer 22 is 3.0 nm or less, the thickness of the buffer layer 22 after forming the piezoelectric element 100 is also 3.0 nm or less. Therefore, it can be seen that the thickness of the buffer layer 22 of the piezoelectric element 100 is preferably 3.0 nm or less.

  In addition, it was confirmed that the crystal structure of the piezoelectric layer 6 according to this embodiment obtained in this experimental example is a perovskite structure and a monoclinic structure. Therefore, it can be inferred that the polarization direction of the piezoelectric layer 6 is an engineered domain arrangement inclined with respect to the direction perpendicular to the film surface. X-ray scattering and Raman scattering were used to identify the crystal structure and the polarization direction of the piezoelectric layer 6.

  6). Next, a modification of the piezoelectric element of the present embodiment will be described with reference to the drawings. Differences from the above-described piezoelectric element 100 shown in FIG. 1 and the manufacturing method thereof (hereinafter referred to as “example of the piezoelectric element 100”) will be described, and description of similar points will be omitted. FIG. 4 is a cross-sectional view schematically showing a piezoelectric element 120 according to this modification.

  In the example of the piezoelectric element 100, the case where the buffer layer 22 remains even when the piezoelectric element 100 is formed has been described. However, as shown in FIG. In the baking step of the sol-gel method in the step of forming the piezoelectric layer 6), it is not necessarily absorbed by the upper and lower layers of the buffer layer 22 and finally left. That is, the piezoelectric element 120 according to the present modification can have no buffer layer 22. In other words, the thickness of the buffer layer 22 of the piezoelectric element 120 of the present modification can be 0 nm. The thickness immediately after the formation of the buffer layer 22 is, for example, 3.0 nm or less and is extremely thin. Therefore, even if the buffer layer 22 is absorbed by the upper and lower layers, the constituent components of the buffer layer 22 are the piezoelectric layer 6. And the influence on the lower electrode 4 is extremely small.

  In addition, the modification mentioned above is an example, Comprising: It is not necessarily limited to this.

  7. Next, a printer having the above-described liquid ejecting head will be described. Here, a case where the printer 600 according to the present embodiment is an inkjet printer will be described.

  FIG. 5 is a perspective view schematically showing the printer 600 according to the present embodiment. The printer 600 includes a head unit 630, a head unit driving unit 610, and a control unit 660. In addition, the printer 600 includes an apparatus main body 620, a paper feeding unit 650, a tray 621 on which the recording paper P is placed, a discharge port 622 for discharging the recording paper P, and an operation panel 670 disposed on the upper surface of the apparatus main body 620. And can be included.

  The head unit 630 includes an ink jet recording head (hereinafter, also simply referred to as “head”) 50 formed of the liquid jet head described above. The head unit 630 further includes an ink cartridge 631 that supplies ink to the head 50, and a transport unit (carriage) 632 on which the head 50 and the ink cartridge 631 are mounted.

  The head unit driving unit 610 can reciprocate the head unit 630. The head unit driving unit 610 includes a carriage motor 641 serving as a drive source for the head unit 630 and a reciprocating mechanism 642 that reciprocates the head unit 630 in response to the rotation of the carriage motor 641.

  The reciprocating mechanism 642 includes a carriage guide shaft 644 supported at both ends by a frame (not shown), and a timing belt 643 extending in parallel with the carriage guide shaft 644. The carriage guide shaft 644 supports the carriage 632 while allowing the carriage 632 to freely reciprocate. Further, the carriage 632 is fixed to a part of the timing belt 643. When the timing belt 643 is caused to travel by the operation of the carriage motor 641, the head unit 630 is reciprocated by being guided by the carriage guide shaft 644. During this reciprocation, ink is appropriately discharged from the head 50 and printing on the recording paper P is performed.

  The control unit 660 can control the head unit 630, the head unit driving unit 610, and the paper feeding unit 650.

  The paper feeding unit 650 can feed the recording paper P from the tray 621 to the head unit 630 side. The paper feed unit 650 includes a paper feed motor 651 serving as a driving source thereof, and a paper feed roller 652 that rotates by the operation of the paper feed motor 651. The paper feed roller 652 includes a driven roller 652a and a drive roller 652b that are vertically opposed to each other with the feeding path of the recording paper P interposed therebetween. The drive roller 652b is connected to the paper feed motor 651.

  The head unit 630, the head unit driving unit 610, the control unit 660, and the paper feeding unit 650 are provided inside the apparatus main body 620.

  In the example described above, the case where the printer 600 is an ink jet printer has been described. However, the printer of the present invention can also be used as an industrial droplet discharge device. As the liquid (liquid material) discharged in this case, various functional materials adjusted to an appropriate viscosity with a solvent or a dispersion medium can be used.

  8). Although the embodiments of the present invention have been described in detail as described above, those skilled in the art will readily understand that many modifications are possible without substantially departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention.

  For example, the above-described piezoelectric element according to the embodiment of the present invention can be applied to a piezoelectric vibrator used for an oscillator, a frequency filter or the like, an angular velocity sensor used for a digital camera, a car navigation system, or the like.

1 is a cross-sectional view schematically showing a piezoelectric element according to an embodiment. Sectional drawing which shows schematically one manufacturing process of the piezoelectric element of this embodiment. FIG. 3 is an exploded perspective view schematically illustrating the liquid ejecting head according to the embodiment. Sectional drawing which shows schematically the modification of the piezoelectric element of this embodiment. 1 is a perspective view schematically illustrating a printer according to an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base | substrate, 4 Lower electrode, 5 Columnar part, 6 Piezoelectric layer, 7 Upper electrode, 22 Buffer layer, 30 Etching stopper layer, 32 Elastic layer, 50 Liquid ejecting head, 51 Nozzle plate, 52 Substrate, 54 Drive part, 55 Elastic plate, 56 housing, 100, 120 piezoelectric element, 511 nozzle hole, 521 opening (cavity), 523 reservoir, 524 supply port, 531 through hole, 600 printer, 610 head unit driving unit, 620 device main body, 621 tray , 622 Discharge port, 630 Head unit, 631 Ink cartridge, 632 Carriage, 641 Carriage motor, 642 Reciprocating mechanism, 643 Timing belt, 644 Carriage guide shaft, 650 Paper feed unit, 651 Paper feed motor, 652 Paper feed roller, 660 Control unit, 670 operations Panel

Claims (11)

A substrate;
A lower electrode formed above the substrate;
A buffer layer formed above the lower electrode, made of a metal oxide with a sodium chloride structure and oriented in (100);
A piezoelectric layer formed above the buffer layer and made of a perovskite oxide;
A piezoelectric element comprising: an upper electrode formed above the piezoelectric layer. In claim 1,
The piezoelectric layer is a piezoelectric element having a pseudo cubic crystal orientation (100) orientation. In claim 1 or 2,
A piezoelectric element in which a crystal structure of the piezoelectric layer is a monoclinic structure. In any one of Claims 1 thru | or 3,
The piezoelectric element, wherein the metal oxide is magnesium oxide. In any one of Claims 1 thru | or 4,
The piezoelectric element, wherein the buffer layer has a thickness of 3 nm or less. In any one of Claims 1 thru | or 5,
The perovskite oxide is represented by the general formula ABO ₃ ,
A includes lead (Pb),
Said B is a piezoelectric element containing zirconium (Zr) and titanium (Ti). In any one of Claims 1 thru | or 6.
The lower electrode is a piezoelectric element made of a platinum group metal. In any one of Claims 1 thru | or 7,
The buffer layer is formed directly on the lower electrode;
The piezoelectric element is a piezoelectric element formed directly on the buffer layer.   A liquid ejecting head comprising the piezoelectric element according to claim 1.   A printer comprising the piezoelectric element according to claim 1. Forming a lower electrode above the substrate;
Forming a buffer layer oriented in (100) above the lower electrode so as to be composed of a metal oxide having a sodium chloride structure;
Forming a piezoelectric layer on the buffer layer so as to be made of a perovskite oxide;
Forming an upper electrode above the piezoelectric layer. A method for manufacturing a piezoelectric element.

Images