JP5919814B2 - Method for manufacturing electromechanical transducer, method for manufacturing droplet discharge head - Google Patents

Description

The present invention relates to a method of manufacturing an electro-mechanical conversion element, and a method of manufacturing a droplet discharge head.

  2. Related Art An ink jet recording apparatus and a liquid ejection head used as an image recording apparatus or an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, etc., a nozzle for ejecting ink droplets, a pressure chamber communicating with the nozzle, and ink in the pressure chamber are added. A device having an electromechanical conversion element such as a piezoelectric element for pressing is known.

  The electromechanical conversion element has, for example, a structure in which an electromechanical conversion film and an upper electrode are stacked on a lower electrode. The electromechanical conversion film which is a thin film can be produced by, for example, a sputtering method, an MOCVD method, a vacuum deposition method, an ion plating method, a sol-gel method, an aerosol deposition method, or the like.

  Here, a method for manufacturing an electromechanical conversion film using a sol-gel method will be described as an example. First, a hydrophobic film pattern is formed on the lower electrode (step 1). The portion of the lower electrode where the hydrophobic film pattern is not formed is hydrophilic. Next, a precursor coating film of the electromechanical conversion film is formed only on the hydrophilic part (the part where the hydrophobic film pattern is not formed) on the lower electrode, and heat treatment is performed (step 2). By this heat treatment, the pattern of the hydrophobic film disappears.

  Since the precursor coating film of the electromechanical conversion film is thin, it cannot be formed in a predetermined film thickness by a single treatment. Therefore, by repeating Step 1 and Step 2 as many times as necessary, the precursor coating film of the electromechanical conversion film is laminated to produce an electromechanical conversion film having a predetermined film thickness.

  However, in the method for producing an electromechanical conversion film, a hot plate, an electric furnace, a laser, or the like is used for the heat treatment in Step 2, but a desired region of the precursor coating film to be heated by heat diffusion or the like. However, it was difficult to heat only the substrate, and there was a problem that the substrate was damaged.

  This invention is made | formed in view of said point, and makes it a subject to provide the manufacturing method of the electromechanical conversion element which can selectively heat only the desired area | region of a heating target object.

Production method of the present electromechanical transducer is formed a step of forming a metal electrode on a substrate, a step of forming the oxide electrode on the metal electrode, on the oxide electrode, a gold Shokumaku A step of partially removing the metal film to form an opening exposing a portion of the oxide electrode; and a functional ink from an inkjet head on the oxide electrode exposed in the opening. And a step of forming an electromechanical conversion film by irradiating the functional ink on the oxide electrode with a laser beam to crystallize the laser beam of the oxide electrode. the light absorption rate for, the rather high than the light absorption rate with respect to the laser beam of the metal film, by heating the oxide electrode by irradiating a laser beam to the functional ink, indirectly heating the functional ink and requirements to be.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electromechanical conversion element which can selectively heat only the desired area | region of a heating target object can be provided.

FIG. 6 is a cross-sectional view illustrating a liquid discharge head using an electromechanical conversion element (part 1); FIG. 6 is a cross-sectional view (part 2) illustrating a liquid discharge head using an electromechanical conversion element. It is a perspective view which illustrates the thin film manufacturing apparatus concerning a 1st embodiment. It is a figure (the 1) which illustrates the thin film manufacturing process which concerns on 1st Embodiment. It is FIG. (The 2) which illustrates the thin film manufacturing process which concerns on 1st Embodiment. FIG. 3 is a third diagram illustrating a thin film manufacturing process according to the first embodiment; It is FIG. (The 1) which illustrates the thin film manufacturing process which concerns on 2nd Embodiment. It is FIG. (The 2) which illustrates the thin film manufacturing process which concerns on 2nd Embodiment. It is FIG. (The 3) which illustrates the thin film manufacturing process which concerns on 2nd Embodiment. It is a perspective view which illustrates an inkjet recording device. It is a side view which illustrates the mechanism part of an inkjet recording device. It is the photograph which measured the contact angle of water in the SAM film formation site. It is the photograph which measured the contact angle of water in the SAM film removal site | part. It is a graph which shows the PE hysteresis curve of the electromechanical conversion element produced in the present Example.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

<First Embodiment>
[Thin film]
First, an electromechanical conversion film constituting an electromechanical conversion element will be described as an example of a thin film manufactured by the thin film manufacturing apparatus according to the first embodiment. The electromechanical transducer is used, for example, as a component part of a liquid discharge head used in an ink jet recording apparatus. FIG. 1 is a cross-sectional view illustrating a liquid discharge head using an electromechanical transducer.

  Referring to FIG. 1, the droplet discharge head 1 includes a nozzle plate 10, a pressure chamber substrate 20, a vibration plate 30, and an electromechanical conversion element 40. The nozzle plate 10 is formed with nozzles 11 that eject ink droplets. The nozzle plate 10, the pressure chamber substrate 20, and the vibration plate 30 may be referred to as a pressure chamber 21 (an ink channel, a pressurized liquid chamber, a pressurized chamber, a discharge chamber, a liquid chamber, or the like) that communicates with the nozzle 11. ) Is formed. The diaphragm 30 forms part of the wall surface of the ink flow path.

The electromechanical conversion element 40 includes an adhesion layer 41, a metal electrode 42 and an oxide electrode 43 serving as a lower electrode, an electromechanical conversion film 44, and an oxide electrode 45 and a metal electrode 46 serving as an upper electrode. And has a function of pressurizing the ink in the pressure chamber 21. The adhesion layer 41 is a layer made of, for example, Ti, TiO ₂ , TiN, Ta, Ta ₂ O ₅ , Ta ₃ N ₅ or the like, and has a function of improving the adhesion between the metal electrode 42 and the vibration plate 30. However, the adhesion layer 41 is not an essential component of the electromechanical conversion element 40.

  In the electromechanical conversion element 40, when a voltage is applied between the metal electrode 42 and the oxide electrode 43 serving as the lower electrode and the oxide electrode 45 and the metal electrode 46 serving as the upper electrode, the electromechanical conversion film 44 is mechanically moved. Is displaced. With the mechanical displacement of the electromechanical conversion film 44, the vibration plate 30 is deformed and displaced, for example, in the lateral direction (d31 direction), and pressurizes the ink in the pressure chamber 21. Thereby, ink droplets can be ejected from the nozzle 11.

  As shown in FIG. 2, a plurality of droplet discharge heads 1 can be arranged in parallel to form the droplet discharge head 2.

As a material of the electromechanical conversion film 44, for example, PZT can be used. PZT is a solid solution of lead zirconate (PbZrO ₃ ) and lead titanate (PbTiO ₃ ). For example, the ratio of PbZrO ₃ and PbTiO ₃ is 53:47, and the chemical formula indicates Pb (Zr _0.53 , Ti _0.47 ) O ₃ , PZT generally indicated as PZT (53/47), etc. Can be used. The characteristics of PZT vary depending on the ratio of PbZrO ₃ and PbTiO ₃ .

When PZT is used as the electromechanical conversion film 44, lead acetate, a zirconium alkoxide compound, and a titanium alkoxide compound are used as starting materials and dissolved in methoxyethanol as a common solvent to prepare a PZT precursor solution. The mixing amount of the lead acetate, zirconium alkoxide compound, and titanium alkoxide compound can be appropriately selected by those skilled in the art depending on the desired composition of PZT (ratio of PbZrO ₃ and PbTiO ₃ ).

  Note that the metal alkoxide compound is easily decomposed by moisture in the atmosphere. Therefore, acetylacetone, acetic acid, diethanolamine or the like may be added to the PZT precursor solution as a stabilizer.

  As a material of the electromechanical conversion film 44, for example, barium titanate or the like may be used. In this case, it is possible to prepare a barium titanate precursor solution by using barium alkoxide and a titanium alkoxide compound as starting materials and dissolving them in a common solvent.

These materials are described by the general formula ABO ₃ and correspond to composite oxides containing A = Pb, Ba, Sr B = Ti, Zr, Sn, Ni, Zn, Mg, and Nb as main components. The specific description is expressed as (Pb _1-x , Ba) (Zr, Ti) O ₃ , (Pb _1-x , Sr) (Zr, Ti) O ₃ , which is the same as Pb of the A site. This is a case where the part Ba or Sr is substituted. Such substitution is possible with a divalent element, and the effect thereof has an effect of reducing characteristic deterioration due to evaporation of lead during heat treatment.

  As a material of the metal electrode 42, a metal or the like that has high heat resistance and forms a SAM film by reaction with alkanethiol described below can be used. Specifically, platinum group metals such as ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir) and platinum (Pt) having low reactivity, and these platinum group metals An alloy material containing can be used.

As a material of the oxide electrode 43, a conductive oxide can be used. As the conductive oxide, specifically, there is a composite oxide described by the chemical formula ABO ₃ and having A = Sr, Ba, Ca, La, B = Ru, Co, Ni as main components, and SrRuO ₃ And CaRuO ₃ , (Sr _1-x Ca _x ) O ₃ which is a solid solution thereof, LaNiO ₃ and SrCoO ₃ , and further, (La, Sr) (Ni _1-y Co _y ) O ₃ which is a solid solution thereof. (Y may be 1). Other oxide materials include IrO ₂ and RuO ₂ .

  The metal electrode 42 and the oxide electrode 43 can be produced by a method such as a vacuum film-forming method such as a sputtering method or vacuum deposition, for example. The lower electrode composed of the metal electrode 42 and the oxide electrode 43 is electrically connected as a common electrode when inputting a signal to the electromechanical transducer 40. Therefore, the diaphragm 30 below the insulator or the surface thereof is insulated. Conductors can be used.

  In the upper electrode, as the material of the metal electrode 46, the same material as that of the metal electrode 42 can be used. Further, as the material of the oxide electrode 45, the same material as that of the oxide electrode 43 can be used.

  As a specific material of the diaphragm 30, for example, silicon can be used. In addition, as a specific material for insulating the surface of the vibration plate 30, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film having a thickness of about several hundred nm to several μm or a stack of these films is laminated. A film or the like can be used. In consideration of the difference in thermal expansion, a ceramic film such as an aluminum oxide film or a zirconia film may be used. The silicon-based insulating film that insulates the surface of the diaphragm 30 can be formed by a CVD method, a thermal oxidation process of silicon, or the like. Further, a metal oxide film such as an aluminum oxide film for insulating the surface of the vibration plate 30 can be formed by a sputtering method or the like.

[Thin film manufacturing equipment]
Next, the structure of the thin film manufacturing apparatus according to the first embodiment will be described. FIG. 3 is a perspective view illustrating the thin film manufacturing apparatus according to the first embodiment. Referring to FIG. 3, in the thin film manufacturing apparatus 3, Y-axis driving means 61 is installed on the gantry 60. On the Y-axis driving means 61, a stage 62 on which the substrate 5 is mounted is installed so as to be driven in the Y-axis direction.

  The stage 62 is usually accompanied by a suction means (not shown) using vacuum or static electricity, so that the substrate 5 can be fixed. Further, a driving means (not shown) that rotates about the Z axis may be mounted on the stage 62 so that the relative inclination between the inkjet head 67 and the laser device 71 described later and the substrate 5 can be corrected.

  An X-axis support member 64 for supporting the X-axis drive means 63 is installed on the gantry 60. The X-axis drive means 63 is provided with a Z-axis drive means 65, and a head base 66 is mounted on the Z-axis drive means 65 so as to be movable in the X-axis and Z-axis directions.

  The Z-axis drive unit 65 can control the distance between an inkjet head 67 and a substrate 5 described later. On the head base 66, an ink jet head 67 that discharges functional ink (for example, PZT precursor solution) is mounted. Functional ink is supplied to the inkjet head 67 from each ink tank 68 via an ink supply pipe (not shown).

  Another Z-axis drive unit 69 is attached to the X-axis drive unit 63, and a laser support member 70 is attached to the Z-axis drive unit 69. A laser device 71 is attached to the laser support member 70. The Z-axis drive unit 69 can control the distance between the laser device 71 and the substrate 5.

  FIG. 3 shows a configuration in which the stage 62 has one axis of freedom in the Y direction, and the inkjet head 67 and the laser device 71 have one axis of freedom in the X direction. It is not limited. For example, the stage 62 may have a degree of freedom of two axes in the X and Y directions, and the inkjet head 67 and the laser device 71 may be fixed. Further, the stage 62 may have a single axis freedom in the Y direction, and the inkjet head 67 and the laser device 71 may be arranged in a line in the Y axis direction.

  Alternatively, the substrate 5 may be fixed, and the inkjet head 67 and the laser device 71 may have a biaxial degree of freedom in the X and Y directions. The X axis and the Y axis need not be orthogonal as long as one plane can be expressed by the X axis and Y axis vectors. For example, the X axis vector and the Y axis vector have angles of 30 degrees, 45 degrees, and 60 degrees. You may do it.

  The thin film manufacturing apparatus 3 includes an apparatus control unit (not shown) and can control the functional ink ejection conditions of the inkjet head 67 and the laser irradiation conditions of the laser apparatus 71. The apparatus control unit has a recording unit (not shown), and can record the crystalline state of the functional ink, the optimum irradiation condition of the laser, and the like on the recording unit.

[Thin film manufacturing method]
Next, the thin film manufacturing method according to the first embodiment will be described. Here, the example which manufactures the electromechanical conversion film | membrane 44 shown in FIG. 1 as a thin film is shown.

  First, in the step shown in FIG. 4A, a metal electrode 42 is formed on a silicon substrate (not shown) whose surface to be the vibration plate 30 is covered with an insulating film. As the metal electrode 42, the aforementioned materials can be used. Next, in the step shown in FIG. 4B, an oxide electrode 43 is formed on the metal substrate 42.

  Although the material suitable for the oxide electrode 43 is as described above, a material having a light absorption rate higher than that of the metal film 49 described later is selected for the laser beam 71x irradiated in the step shown in FIG. The light absorption rate of the oxide electrode 43 with respect to the laser beam 71x is preferably 20% or more, and more preferably 50% or more, higher than the light absorption rate of the metal film 49 with respect to the laser beam 71x.

  Next, in the step shown in FIG. 4C, a metal film 49 is formed on the oxide electrode 43. As the metal film 49, for example, a platinum group metal or the like can be used. The metal substrate 42, the oxide electrode 43, and the metal film 49 can be formed by a method such as a vacuum film forming method such as a sputtering method or vacuum deposition.

  Next, in the step shown in FIG. 4D, the metal film 49 is partially removed by a photolithography method, an etching method, or the like, and an opening 49x exposing a part of the oxide electrode 43 is formed. A recess is formed on the inner surface of the opening 49x and the surface of the oxide electrode 43 exposed in the opening 49x. Thereby, the metal film 49 becomes uneven.

  Next, in the step shown in FIG. 5A, the structure (corresponding to the substrate 5 in FIG. 3) manufactured in the step shown in FIG. 4D is placed on the stage 62 of the thin film manufacturing apparatus 3. Then, using a known alignment device (CCD camera, CMOS camera, or the like) or the like, the position, inclination, etc. of the structure manufactured in the step shown in FIG.

  Then, the inkjet head 67 is driven on the X axis, the stage 62 on which the structure manufactured in the process shown in FIG. 4D is mounted is driven on the Y axis, and the inkjet head 67 is arranged on the stage 62. . Then, the functional ink 44 a is discharged from the inkjet head 67 onto the oxide electrode 43 exposed in the opening 49 x (in the recess) of the metal film 49. As the functional ink 44a, for example, a PZT precursor solution can be used.

  Next, in the step shown in FIG. 5B, the laser device 71 is driven on the X axis, and if necessary, the stage 62 is driven on the Y axis, and the laser device 71 is arranged on the stage 62. Then, the laser device 71 irradiates the functional ink 44a with the laser beam 71x and heats it. Note that the shape of the irradiation region of the laser light 71x is preferably equal to or greater than the shape of the functional ink 44a. The functional ink 44a irradiated with the laser beam 71x evaporates the solvent, is thermally decomposed, and is further crystallized to become the functional ink 44b.

  As the laser device 71, for example, a semiconductor laser device, a YAG laser device, or the like can be used. The laser beam 71x can be continuous irradiation light or pulsed light. After the continuous irradiation light is irradiated as the laser light 71x, pulse light may be further irradiated.

  As described above, the light absorption rate of the oxide electrode 43 with respect to the laser light 71x is higher than the light absorption rate of the metal film 49 with respect to the laser light 71x. Therefore, when the laser beam 71x is irradiated, the metal film 49 is not heated so much and the oxide electrode 43 at the bottom of the functional ink 44b is selectively heated. Thereby, the possibility of damaging the region other than the portion to be heated due to heat can be reduced.

  The wavelength of the laser beam 71x is preferably set to 400 nm or more (for example, about 400 nm to 10,000 nm), which is a region where the light absorption rate of the oxide electrode 43 is relatively high. More specifically, the functional ink 44a almost transmits the laser beam 71x having a wavelength of 400 nm or more and hardly absorbs it. For example, when the functional ink 44a is PZT, the light absorptance with respect to laser light having a wavelength of 1 μm is about 0%. Further, as described above, the light absorption rate of the metal film 49 is lower than that of the oxide electrode 43.

  Therefore, the functional ink 44a is not directly heated, but the oxide electrode 43 on which the functional ink 44a is mounted is heated, and the functional ink 44a is indirectly heated accordingly. Therefore, it is preferable that the wavelength of the laser beam 71x is 400 nm or more, which is a region where the light absorption rate of the oxide electrode 43 is relatively high.

  If the direct heating method is used, there is a possibility that temperature unevenness may occur in the irradiated portion due to unevenness of the beam profile of the laser beam. However, by using the indirect heating method, the functional ink 44a is uniformly distributed within the irradiation surface. Can be heated.

  The moving speed of the stage 62 can be about 10 mm / s to 1000 mm / s, and the power of the laser beam 71x can be about several W to several tens W. The beam diameter of the laser beam 71x can be about several tens of μm to several hundreds of μm, and the beam profile can be a general Gaussian profile. Note that it is preferable that the beam profile of the laser beam 71x be a top hat shape, so that the functional ink 44a can be heated more uniformly.

  The thickness of the functional ink 44b (for example, PZT thin film) crystallized in the process shown in FIG. 5B is about several tens of nm. Since this film thickness is insufficient, after the step shown in FIG. 5B, the steps shown in FIGS. 5A and 5B are repeated as many times as necessary. As a result, as shown in FIG. 6A, the functional ink 44b is laminated, and the functional ink film crystallized with an arbitrary pattern and thickness (for example, about several μm) on the oxide electrode 43. That is, the electromechanical conversion film 44 is produced.

  Next, in the step shown in FIG. 6B, an oxide electrode 45 is formed on the metal film 49 so as to cover the electromechanical conversion film 44. The material and the film forming method of the oxide electrode 45 can be the same as those shown in FIG. Next, in the step shown in FIG. 6C, a metal electrode 46 is formed on the oxide electrode 45. The material and film forming method of the metal electrode 46 can be the same as those shown in FIG.

  Next, in the step shown in FIG. 6D, a resist (not shown) is formed on the electromechanical conversion film 44 of the structure shown in FIG. 6C, and a resist (not shown) is formed. The oxide electrode 45, the metal electrode 46, and the metal film 49 are removed by etching. Thereafter, the resist (not shown) is removed. As a result, the electromechanical conversion film 44 is laminated on the metal electrode 42 and the oxide electrode 43 serving as the lower electrode, and the oxide electrode 45 and the metal electrode 46 serving as the upper electrode are further laminated on the electromechanical conversion film 44. .

  As described above, in the first embodiment, a metal film having a lower light absorptance with respect to laser light irradiated than the oxide electrode is selectively formed on the oxide electrode, and the metal film is not formed. Functional ink is ejected onto the physical electrode. Then, the functional ink is irradiated with laser light. Accordingly, since the oxide electrode at the bottom of the functional ink is selectively heated, it is possible to reduce the possibility that the region other than the portion to be heated is damaged by heat.

  Although the SAM film (described later) is not used in the first embodiment, when the electromechanical conversion film 44 is precisely formed, the metal film 49 is formed after the step shown in FIG. It is preferable to perform the step shown in FIG. 5A after the SAM film is formed thereon.

<Second Embodiment>
In the second embodiment, a thin film forming method different from that in the first embodiment is illustrated. In the description of the second embodiment, the description of the common parts with the first embodiment may be omitted.

[SAM film patterning]
First, as shown in FIG. 7, a SAM (Self Assembled Monolayer) film 50 having a predetermined pattern is formed on the surface of the metal electrode 42. Specifically, in the step shown in FIG. 7A, a metal electrode 42 is formed on a silicon substrate (not shown) whose surface to be the vibration plate 30 is covered with an insulating film. As the metal electrode 42, the aforementioned materials can be used.

  Next, in the step shown in FIG. 7B, the metal electrode 42 is immersed in a SAM material made of alkanethiol or the like. Thereby, the SAM material reacts on the surface of the metal electrode 42 and the SAM film 50 adheres, and the surface of the metal electrode 42 can be made water repellent. Although alkanethiol has different reactivity and hydrophobicity (water repellency) depending on the molecular chain length, it is usually prepared by dissolving a molecule having 6 to 18 carbon atoms in an organic solvent such as alcohol, acetone or toluene. Usually, the concentration of alkanethiol is about several moles / liter. After a predetermined time, the metal electrode 42 is taken out, and the excess molecules are washed by substitution with a solvent and dried.

  Next, in a step shown in FIG. 7C, a photoresist 51 having an opening 51x is formed on the SAM film 50 formed on the surface of the metal electrode 42 by a known photolithography method. Next, in the step shown in FIG. 7D, the SAM film 50 exposed in the opening 51x is removed by dry etching or the like, and the photoresist 51 is further removed. As a result, the SAM film 50 having a predetermined pattern is formed on the surface of the metal electrode 42.

  The region where the SAM film 50 is formed on the surface of the metal electrode 42 is hydrophobic. On the other hand, the region where the surface of the metal electrode 42 is exposed after the SAM film 50 is removed becomes hydrophilic. By using the contrast of the surface energy, it becomes possible to separate the solutions described in detail below.

  After the step shown in FIG. 7A, a photoresist is formed in a predetermined region on the surface of the metal electrode 42 (a region corresponding to the opening 51x in FIG. 7C), and the photoresist is formed. The SAM treatment may be performed on the unexposed region to remove the photoresist. As a result, a SAM film 50 having a predetermined pattern is formed on the surface of the metal electrode 42 as in the step shown in FIG.

  After the step shown in FIG. 7B, a photomask having an opening that exposes a region where the SAM film 50 is to be removed is disposed on the SAM film 50, and ultraviolet light, oxygen plasma, or the like is applied through the photomask. The surface of the metal electrode 42 may be irradiated to remove the SAM film 50 in the exposed portion (in the opening). As a result, a SAM film 50 having a predetermined pattern is formed on the surface of the metal electrode 42 as in the step shown in FIG.

[Formation of oxide electrode]
Next, in the step shown in FIG. 8, the oxide electrode 43 is formed. The materials suitable for the oxide electrode 43 are as described above, but a material having a light absorption rate higher than that of the metal electrode 42 with respect to the laser beam 71x irradiated in the step shown in FIG. The light absorptance of the oxide electrode 43 with respect to the laser light 71x is preferably 20% or more, and more preferably 50% or more higher than the light absorption of the metal electrode 42 with respect to the laser light 71x.

  Specifically, in the step shown in FIG. 8A, a metal electrode 42 (corresponding to the substrate 5 in FIG. 3) having a SAM film 50 with a predetermined pattern formed on the surface is provided on the stage 62 of the thin film manufacturing apparatus 3. Place. Then, the position and inclination of the metal electrode 42 are aligned using a known alignment device (CCD camera, CMOS camera, or the like).

  Then, the inkjet head 67 is driven on the X axis, the stage 62 on which the metal electrode 42 is placed is driven on the Y axis, and the inkjet head 67 is disposed on the stage 62. Then, the functional ink 43 a is ejected from the inkjet head 67 to a region (hydrophilic region) where the SAM film 50 does not exist on the surface of the metal electrode 42. At this time, due to the contrast of the surface energy, the functional ink 43a spreads wet only in the region where the SAM film 50 does not exist (hydrophilic region).

As described above, the functional ink 43a is formed only in the region where the SAM film 50 does not exist (hydrophilic region) by utilizing the contrast of the surface energy. In addition, the process can be simplified and the process can be simplified. As the functional ink 43a, for example, a LaNiO ₃ solution can be used.

  Next, in the step shown in FIG. 8B, the laser device 71 is driven on the X-axis, and if necessary, the stage 62 on which the metal electrode 42 is placed is driven on the Y-axis. A laser device 71 is disposed. Then, the laser device 71 irradiates the functional ink 43a wetted and spread in the step shown in FIG. The functional ink 43a irradiated with the laser light 71x is evaporated, thermally decomposed, and further crystallized to become a functional ink film having a film thickness of about several tens of nm, that is, the oxide electrode 43. Note that the SAM film 50 disappears in the step shown in FIG.

  As the laser device 71, for example, a semiconductor laser device, a YAG laser device, or the like can be used. However, instead of the laser device 71, the functional ink 43a may be heated using an oven, lamp annealing, or the like.

  Here, an example in which the functional ink 43a is patterned by the ink jet method has been introduced. However, the functional ink 43a is coated on the entire surface by a sputtering method or a spin coating method, and a desired pattern is formed by a photolithography method or an etching method. The obtaining method may be used.

[Formation of electromechanical conversion film]
Next, as shown in FIG. 9, an electromechanical conversion film 44 is formed on the surface of the oxide electrode 43. Specifically, in the process shown in FIG. 9A, a metal electrode 42 (substrate of FIG. 3) having a SAM film 50 and an oxide electrode 43 with a predetermined pattern formed on the surface 62 on the stage 62 of the thin film manufacturing apparatus 3. 5). Then, the position and inclination of the metal electrode 42 are aligned using a known alignment device (CCD camera, CMOS camera, or the like).

  Then, the inkjet head 67 is driven on the X axis, the stage 62 on which the metal electrode 42 is placed is driven on the Y axis, and the inkjet head 67 is disposed on the stage 62. Then, the functional ink 44a is ejected from the inkjet head 67 onto the surface (hydrophilic region) of the oxide electrode 43 where the SAM film 50 does not exist. At this time, due to the contrast of the surface energy, the functional ink 44a wets and spreads only in a region (hydrophilic region) where the SAM film 50 does not exist.

  In this way, by forming the functional ink 44a only in the region where the SAM film 50 does not exist (hydrophilic region) using the contrast of the surface energy, the amount of the solution to be applied is changed to a process such as a spin coating method. In addition, the process can be simplified and the process can be simplified. For example, a PZT precursor solution can be used as the functional ink 44a.

  Next, in the step shown in FIG. 9B, the laser device 71 is driven on the X axis, and if necessary, the stage 62 on which the metal electrode 42 is placed is driven on the Y axis, A laser device 71 is disposed. Then, the laser device 71 irradiates the functional ink 44a wetted and spread in the step shown in FIG. The functional ink 44a irradiated with the laser light 71x is vaporized and thermally decomposed into the functional ink 44b that has been thermally decomposed.

  As the laser device 71, for example, a semiconductor laser device, a YAG laser device, or the like can be used. The laser beam 71x can be continuous irradiation light or pulsed light. After the continuous irradiation light is irradiated as the laser light 71x, pulse light may be further irradiated.

  As described above, the light absorption rate of the oxide electrode 43 with respect to the laser beam 71x is higher than the light absorption rate of the metal electrode 42 with respect to the laser beam 71x. Therefore, when the laser beam 71x is irradiated, the metal electrode 42 is not heated so much and the oxide electrode 43 at the bottom of the functional ink 44b is selectively heated. Thereby, the possibility of damaging the region other than the portion to be heated due to heat can be reduced. Since the metal electrode 42 is hardly heated, the SAM film 50 formed on the metal electrode 42 does not disappear.

  The film thickness of the functional ink 43b (for example, PZT thin film) crystallized in the process shown in FIG. 9B is about several tens of nm, and this film thickness is insufficient. Therefore, after the step shown in FIG. 9B, the steps shown in FIG. 9A and FIG. 9B are repeated as many times as necessary. As a result, the functional ink 44b is laminated, and the functional ink film crystallized with an arbitrary pattern and thickness (for example, about several μm), that is, the electromechanical conversion film 44, is formed on the oxide electrode 43.

  As described above, since the SAM film 50 does not disappear in the process shown in FIG. 9B, it is not necessary to perform the same process as that in FIG. That is, when the electromechanical conversion film is formed, if the SAM film is applied only once, it is not removed to the end, and the man-hours can be greatly reduced.

  As described above, in the second embodiment, the oxide electrode is selectively formed on the metal electrode having a lower light absorption rate with respect to the laser beam irradiated than the oxide electrode, and the functional ink is formed on the oxide electrode. To discharge. Then, the functional ink is irradiated with laser light. Accordingly, since the oxide electrode at the bottom of the functional ink is selectively heated, it is possible to reduce the possibility that the region other than the portion to be heated is damaged by heat.

<Third Embodiment>
In the third embodiment, an example of an ink jet recording apparatus on which the liquid discharge head 2 (see FIG. 2) manufactured by the thin film manufacturing apparatus 3 is mounted is shown. FIG. 10 is a perspective view illustrating an ink jet recording apparatus. FIG. 11 is a side view illustrating the mechanism unit of the ink jet recording apparatus.

  Referring to FIGS. 10 and 11, the ink jet recording apparatus 4 is an ink jet recording which is an embodiment of a liquid discharge head 2 mounted on a carriage 93 movable in the main scanning direction inside a recording apparatus main body 81. A print mechanism unit 82 including an ink cartridge 95 that supplies ink to the head 94 and the inkjet recording head 94 is accommodated.

  A paper feed cassette 84 (or a paper feed tray) on which a large number of sheets 83 can be stacked can be detachably attached to the lower portion of the recording apparatus main body 81. Further, the manual feed tray 85 for manually feeding the paper 83 can be turned over. The paper 83 fed from the paper feed cassette 84 or the manual feed tray 85 is taken in, and after a required image is recorded by the printing mechanism unit 82, the paper is discharged to a paper discharge tray 86 mounted on the rear side.

  The printing mechanism 82 holds the carriage 93 slidably in the main scanning direction with a main guide rod 91 and a sub guide rod 92 which are guide members horizontally mounted on left and right side plates (not shown). The carriage 93 has an inkjet recording head 94 that ejects ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk), and a plurality of ink ejection ports (nozzles) in the main scanning direction. They are arranged in the intersecting direction and mounted with the ink droplet ejection direction facing downward. Further, the carriage 93 is mounted with replaceable ink cartridges 95 for supplying ink of each color to the ink jet recording head 94.

  The ink cartridge 95 has an air port (not shown) that communicates with the atmosphere above, an air port (not shown) that supplies ink to the ink jet recording head 94 below, and a porous body (not shown) filled with ink inside. ing. The ink supplied to the inkjet recording head 94 is maintained at a slight negative pressure by the capillary force of the porous body. Further, although the respective color heads are used here as the ink jet recording head 94, one head having nozzles for ejecting ink droplets of each color may be used.

  The carriage 93 is slidably fitted to the main guide rod 91 on the downstream side in the paper conveyance direction, and is slidably mounted on the sub guide rod 92 on the upstream side in the paper conveyance direction. In order to move and scan the carriage 93 in the main scanning direction, a timing belt 100 is stretched between a driving pulley 98 and a driven pulley 99 that are rotationally driven by the main scanning motor 97, so that the main scanning motor 97 is forward / reverse. The carriage 93 is reciprocated by the rotation. The timing belt 100 is fixed to the carriage 93.

  Further, the ink jet recording apparatus 4 reverses and feeds the paper feed roller 101 for separating and feeding the paper 83 from the paper feed cassette 84, the friction pad 102, the guide member 103 for guiding the paper 83, and the fed paper 83. A conveyance roller 104, a conveyance roller 105 that is pressed against the circumferential surface of the conveyance roller 104, and a leading end roller 106 that defines a feeding angle of the sheet 83 from the conveyance roller 104 are provided. As a result, the paper 83 set in the paper feed cassette 84 is conveyed to the lower side of the ink jet recording head 94. The transport roller 104 is rotationally driven by a sub-scanning motor 107 through a gear train.

  The printing receiving member 109 which is a paper guide member guides the paper 83 sent out from the conveying roller 104 corresponding to the movement range of the carriage 93 in the main scanning direction on the lower side of the ink jet recording head 94. On the downstream side of the printing receiving member 109 in the sheet conveyance direction, a conveyance roller 111 and a spur 112 that are rotationally driven to send out the sheet 83 in the sheet discharge direction are provided. Further, a paper discharge roller 113 and a spur 114 for sending the paper 83 to the paper discharge tray 86, and guide members 115 and 116 for forming a paper discharge path are provided.

  During image recording, the inkjet recording head 94 is driven in accordance with the image signal while moving the carriage 93, thereby ejecting ink onto the stopped paper 83 to record one line and transporting the paper 83 by a predetermined amount. After that, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing end of the paper 83 reaches the recording area, the recording operation is terminated and the paper 83 is discharged.

  A recovery device 117 for recovering defective ejection of the inkjet recording head 94 is provided at a position outside the recording area on the right end side in the movement direction of the carriage 93. The recovery device 117 includes a cap unit, a suction unit, and a cleaning unit. The carriage 93 is moved to the recovery device 117 side during printing standby, and the ink jet recording head 94 is capped by the capping unit, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant, and stable ejection performance is maintained.

  When ejection failure occurs, the ejection port of the ink jet recording head 94 is sealed with a capping unit, and bubbles and the like are sucked out from the ejection port with the suction unit through the tube. Also, ink or dust adhering to the ejection port surface is removed by the cleaning means, and the ejection failure is recovered. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  Thus, since the inkjet recording head 94 which is one embodiment of the liquid ejection head 2 manufactured by the thin film manufacturing apparatus 3 is mounted in the inkjet recording apparatus 4, there is no ink droplet ejection defect due to vibration plate drive failure. Since stable ink droplet ejection characteristics can be obtained, image quality can be improved.

[Example 1]
First, using a sputtering method, a metal film composed of a platinum-based metal serving as a metal electrode, LaNiO ₃ serving as an oxide electrode, and a platinum-based metal was formed in this order on a silicon substrate. Then, the metal film was partially removed by a photolithography method, an etching method, or the like to form an opening, and a recess was formed on the inner surface of the opening and the surface of the oxide electrode exposed in the opening. Note that the light absorption rate of LaNiO ₃ with respect to laser light having a wavelength of 980 nm is about 70%, and the light absorption rate of platinum with respect to laser light having a wavelength of 980 nm is about 20%.

Next, the sol-gel solution of the PZT precursor is poured into the recess by dipping. By irradiating the region where the sol-gel solution is accumulated with a laser beam having a wavelength of 980 nm that transmits the sol-gel solution, the oxide electrode (LaNiO ₃ ) at the bottom of the sol-gel solution is heated, and the sol-gel solution is dried and crystallized. As a result, a PZT film was formed. By repeating this, a PZT film having a film thickness of 5 μm could be obtained.

[Example 2]
In this example, a thermal oxide film (film thickness 1 μm) was formed on a silicon wafer, and a titanium film (film thickness 50 nm) was formed by sputtering as an adhesion layer. Subsequently, a platinum film (thickness: 200 nm) was formed by sputtering as a metal electrode.

Then, _CH 3 _{(CH 2)} using 6 -SH to alkanethiol, concentration 0.01 mol / l (solvent: isopropyl alcohol) is dipped into the solution, it was subjected to SAM process. Then, after washing and drying with isopropyl alcohol, the process proceeds to a patterning process.

  After the SAM film treatment, when the contact angle of water was measured at the SAM film formation site (on the SAM film), the contact angle of water on the SAM film was 92.2 ° (see FIG. 12). On the other hand, when the contact angle of water was measured on the platinum sputtered film before the SAM treatment, the contact angle of water on the platinum sputtered film was 5 ° or less (complete wetting). From this result, it can be seen that the SAM film treatment was appropriately performed.

  Next, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) was formed by spin coating, a resist pattern was formed by ordinary photolithography, and then an oxygen plasma treatment was performed to remove the exposed SAM film. The residual resist after treatment was dissolved and removed with acetone, and the same contact angle evaluation was performed. As a result, the contact angle of water at the SAM film removal site was 5 ° or less (complete wetting) (see FIG. 13). That of the covered site showed a value of 92.4 °. From this result, it can be confirmed that the SAM film is appropriately patterned.

  As another type of patterning, a resist pattern was previously formed with the same resist work, and after the same SAM film treatment, the resist was removed with acetone, and the contact angle was measured. The contact angle on the resist-covered platinum film was 5 ° or less (complete wetting), and that at other sites was 92.0 °, confirming that the SAM film was appropriately patterned.

  As another method, ultraviolet irradiation using a shadow mask was performed. Specifically, irradiation was performed for 10 minutes using vacuum ultraviolet light having a wavelength of 176 nm from an excimer lamp. The contact angle of the irradiated part was 5 ° or less (complete wetting), and that of the unirradiated part was 92.2 °, confirming that the SAM film was appropriately patterned.

Next, a LaNiO ₃ solution was applied onto the patterned SAM film by an ink jet method, followed by drying, thermal decomposition, and crystallization using an oven, laser, lamp annealing, or the like. Here, although provides examples of patterning the LaNiO ₃ solution by an ink jet method, a sputtering method or a spin coating method and coating the LaNiO ₃ solution on the entire surface to obtain a desired pattern by photolithography and etching method A method may be used.

Next, the SAM film for forming the PZT precursor is formed in the same manner as the procedure of applying the LaNiO ₃ solution. Since LaNiO ₃ is an oxide and no SAM film is formed, photolithography and etching steps can be omitted.

  In the synthesis of the precursor coating solution, lead acetate trihydrate, isopropoxide titanium, and isopropoxide zirconium were used as starting materials. Crystal water of lead acetate was dissolved in methoxyethanol and then dehydrated. The lead amount is 10 mol% excess relative to the stoichiometric composition. This is to prevent crystallinity deterioration due to so-called lead loss during heat treatment.

  Isopropoxide titanium and isopropoxide zirconium were dissolved in methoxyethanol, the alcohol exchange reaction and the esterification reaction were advanced, and the PZT precursor solution was synthesized by mixing with the methoxyethanol solution in which the lead acetate was dissolved. The PZT concentration was 0.1 mol / l.

  The film thickness obtained by a single sol-gel film formation is preferably 100 nm, and the precursor concentration is optimized from the relationship between the film formation area and the amount of applied precursor (thus not limited to 0.1 mol / l). .

  This precursor solution was applied onto the patterned SAM film by the inkjet method (see FIG. 9A). By discharging only the hydrophilic portion without discharging droplets on the SAM film by the ink jet method, a coating film was formed only on the hydrophilic portion due to the contact angle contrast.

  This was treated as a first heating (solvent drying) at 120 ° C. by laser light irradiation, and the organic matter was thermally decomposed to obtain a film thickness of 90 nm. The laser beam used here is a semiconductor laser having a wavelength of 980 nm and has a spot diameter wider than the width for forming PZT.

Subsequently, the PZT precursor is applied by an inkjet coating apparatus. The film thickness at this time was 180 nm. Next, the LaNiO ₃ film is heated by laser irradiation to indirectly dry the PZT precursor. Here, the light absorption rate of the LaNiO ₃ solution with respect to the wavelength of 980 nm is about 70%, and the light absorption rate of platinum is about 20%. Therefore, the temperature of platinum hardly increases. Therefore, the SAM film formed on platinum is not removed. The film thickness of the PZT precursor after drying was 90 nm.

  The previous step was repeated 6 times to obtain an electromechanical conversion film having a thickness of 540 nm, followed by thermal decomposition treatment. Defects such as cracks did not occur in the electromechanical conversion film. Further, selective application and drying of the PZT precursor were performed 6 times, and crystallization treatment was performed by laser irradiation. Defects such as cracks did not occur in the electromechanical conversion film. The film thickness of the electromechanical conversion film reached 1000 nm. In these heating processes by laser light irradiation, the SAM film was not removed, and the contact angle with respect to water was maintained at 90 ° or more until the end.

Next, the SAM film is removed by hot plate heating, and an upper electrode (platinum) is formed on the patterned electromechanical conversion film to produce an electromechanical conversion element. (Piezoelectric constant) was evaluated. FIG. 14 is a graph showing a PE hysteresis curve of the electromechanical transducer produced in this example. The relative dielectric constant of the electromechanical conversion film is 1220, the dielectric loss is 0.02, the remanent polarization is 19.3 uC / cm ² , and the coercive electric field is 36.5 kV / cm, which is equivalent to that of an ordinary ceramic sintered body. I understood that I have it.

  The electro-mechanical conversion ability of the electromechanical transducer was calculated by measuring the amount of deformation by applying an electric field with a laser Doppler vibrometer and fitting it by simulation. The piezoelectric constant d31 was −120 pm / V, which was also the same value as the ceramic sintered body. This is a characteristic value that can be sufficiently designed as a droplet discharge head.

  Apart from the above, further thickening was attempted without arranging the upper electrode. That is, crystallization treatment was performed every time pyrolysis annealing was repeated up to 6 times, and when this was repeated 10 times, a patterned PZT film having a thickness of 5 μm was obtained without defects such as cracks.

  In general, the PZT precursor is dried, pyrolyzed, and crystallized by a hot plate or an oven, but only the PZT film is heated and the SAM film is heated by performing all the heating steps by laser light irradiation. Not. Therefore, if the SAM film is applied only once at the beginning, it is not removed until the end, and the man-hour can be greatly reduced.

[Example 3]
In Example 2, using the thin film forming apparatus 3 shown in FIG. 3, platinum was applied only to a necessary portion on the PZT film to form an upper electrode. When coating, the coating area was defined using the contact angle contrast in the same manner as when the PZT precursor was coated.

Since it is necessary to apply the upper electrode to a region smaller than the PZT film pattern in order to prevent a short circuit, it is preferable to provide a water repellent part also on the PZT film. In this embodiment, after patterning a resist in a region where platinum is not formed, liquid platinum is applied to a region where the resist is not formed. Then, the platinum was dried at 120 ° C., after which the resist was peeled off and finally sintered at 250 ° C. The film thickness after firing was 0.5 μm, and the specific resistance was 5 × 10 ⁻⁶ ohm centimeter, and good results were obtained.

[Example 4]
As electrode films of other platinum group elements, ruthenium, iridium, and rhodium were formed by sputtering on a silicon wafer with a thermal oxide film in which each titanium adhesion layer was disposed. The SAM molecule and the treatment method are the same as in Example 2. Further, platinum-rhodium (rhodium concentration: 15 wt%) was also used as a platinum group alloy. Moreover, it also performed about the sample which has arrange | positioned the iridium metal or the platinum film | membrane on the iridium oxide film.

  The water contact angle at the SAM membrane removal site was 5 ° or less (complete wetting), while that at the SAM membrane placement site was 90.0 ° in all samples. That is, good results were obtained for any metal.

  The preferred embodiments and examples have been described in detail above, but the present invention is not limited to the above-described embodiments and examples, and the above-described embodiments are not deviated from the scope described in the claims. Various modifications and substitutions can be made to the embodiments.

DESCRIPTION OF SYMBOLS 1, 2 Droplet discharge head 3 Thin film manufacturing apparatus 4 Inkjet recording apparatus 5 Substrate 10 Nozzle plate 11 Nozzle 20 Pressure chamber substrate 21 Pressure chamber 30 Vibration plate 40 Electromechanical conversion element 41 Adhesion layer 42, 46 Metal electrode 43, 45 Oxide Electrode 43a, 43b, 44a, 44b Functional ink 44 Electromechanical conversion film 49 Metal film 49x, 51x Opening 50 SAM film 51 Photoresist 60 Mount 61 Y-axis drive means 62 Stage 63 X-axis drive means 64 X-axis support member 65 69 Z-axis drive means 66 Head base 67 Inkjet head 68 Ink tank 70 Laser support member 71 Laser device 71x Laser light 81 Recording device main body 82 Printing mechanism 83 Paper 84 Paper feed cassette (or paper feed tray)
85 Manual feed tray 86 Paper discharge tray 91 Main guide rod 92 Subordinate guide rod 93 Carriage 94 Inkjet recording head 95 Ink cartridge 97 Main scanning motor 98 Drive pulley 99 Driven pulley 100 Timing belt 101 Paper feed roller 102 Friction pad 103 Guide member 104 Transport roller 105 Conveying roller 106 Leading end roller 107 Sub-scanning motor 109 Printing receiving member 111 Conveying roller 112 Spur 113 Paper discharge roller 114 Spur 115, 116 Guide member 117 Recovery device

Japanese translation of PCT publication No. 2002-543429

Claims (13)

Forming a metal electrode on the substrate;
Forming an oxide electrode on the metal electrode;
On the oxide electrode, and forming a gold Shokumaku,
Removing the metal film partially to form an opening exposing a portion of the oxide electrode;
Discharging functional ink from an inkjet head onto the oxide electrode exposed in the opening;
Forming an electromechanical conversion film by irradiating the functional ink on the oxide electrode with laser light to crystallize, and
The light absorption rate for the laser light of said oxide electrode is rather higher than the light absorption rate with respect to the laser beam of the metal film,
A method for producing an electromechanical transducer , wherein the functional ink is indirectly heated by irradiating the functional ink with a laser beam to heat the oxide electrode . Forming a metal electrode on the substrate;
Forming a liquid repellent film on the metal electrode ;
Forming a photoresist having an opening on the liquid repellent film;
Removing the liquid repellent film exposed in the opening and the photoresist;
Discharging a first functional ink for forming an oxide electrode in a region corresponding to the opening, on the metal electrode, where the liquid repellent film does not exist;
Irradiating the first functional ink with laser light and crystallizing to form an oxide electrode;
Discharging a second functional ink onto the oxide electrode with an inkjet head ;
Irradiating the second functional ink with a laser beam to form an electromechanical conversion film, and
The light absorption rate for the laser light of said oxide electrode is rather higher than the light absorption rate with respect to the laser beam of the metal electrode,
Production of an electromechanical transducer that heats the second functional ink by irradiating the second functional ink with laser light and heating the oxide electrode at the bottom of the second functional ink. Method. The light absorption rate with respect to the laser beam of the oxide electrode, the manufacturing method of electromechanical transducer of more than 20% than the light absorption coefficient higher Claim 1 wherein for said laser beam of said metal film. The light absorption rate with respect to the laser beam, before Symbol manufacturing method of electromechanical transducer of high claim 2, wherein 20% or more than the light absorption rate with respect to the laser beam of the metal electrodes of the oxide electrode. The method for producing an electromechanical conversion element according to claim 1 or 3 , wherein in the step of forming the electromechanical conversion film, the functional ink is dried, pyrolyzed, and crystallized to form the electromechanical conversion film. Shape of the irradiation area of the laser beam, according to claim 1 is shaped least equivalent of the functional ink, 3, or manufacturing method of electromechanical transducer according to one of 5. In the step of forming the electro-mechanical conversion layer, the second functional ink is dry, pyrolysis, and the manufacturing method of electromechanical transducer of claim 2 or 4, wherein crystallized becomes the electromechanical conversion film . The method of manufacturing an electromechanical transducer according to any one of claims 2, 4, and 7 , wherein a shape of the laser light irradiation region is equal to or greater than a shape of the second functional ink . The method for producing an electromechanical transducer according to claim 1 , wherein the functional ink contains a metal complex oxide. The method for manufacturing an electromechanical transducer according to any one of claims 2, 4, 7, and 8 , wherein the second functional ink contains a composite oxide of metal. Method for manufacturing electromechanical transducer according to any one of claims 1 to 10 wavelengths of the laser beam is 400nm or more. After the step of forming the electro-mechanical conversion film manufacturing method of electromechanical transducer of any one of claims 1 to 11 comprising forming the other electrode on the electro-mechanical transducer film. A liquid discharge head manufactured by providing a nozzle plate, a pressure chamber substrate, and a vibration plate on an electromechanical transducer manufactured using the method for manufacturing an electromechanical transducer according to any one of claims 1 to 12 . Production method.