JP6390177B2 - Method for producing electro-mechanical conversion film - Google Patents

Description

The present invention relates to an electro - relates to the manufacture how the transducer layer.

  The electro-mechanical conversion element has, for example, a laminated structure in which an electro-mechanical conversion film having a desired film thickness is disposed between electrodes.

  Conventionally, as a method for producing an electro-mechanical conversion film, a step of modifying the surface of the base substrate, a step of forming a precursor coating film of the electro-mechanical conversion film, and a step of heat-treating the precursor coating film are desired. The method of repeating until the film thickness of 1 is obtained is known (for example, refer to Patent Document 1).

  However, in the conventional technique described above, since the substrate is heated to a high temperature in the heat treatment step, the surface-modified state is not maintained on the substrate after the heat treatment. For this reason, when the above-described steps are repeated until an electromechanical conversion film having a desired film thickness is obtained, it is necessary to perform surface modification on the base substrate every time before the step of forming the precursor coating film. It is inefficient in terms of sex.

  Accordingly, an object of the present invention is to provide a method for producing an electro-mechanical conversion film that is not limited to a substrate material and has excellent productivity.

In one proposal, a sol-gel liquid, which is a precursor of an electro-mechanical conversion film, is partially applied to the surface of a first electrode provided on a substrate by an inkjet method, and a patterned sol-gel film is applied. A coating step for forming, a drying step for drying the sol-gel film, a thermal decomposition step for thermally decomposing the sol-gel film by irradiating the sol-gel film with a flash lamp, and the sol-gel film And a crystallization step of crystallizing the sol-gel film by irradiating with a flash lamp.

  According to one embodiment, it is possible to provide a method for producing an electromechanical conversion film that is not limited to a substrate material and has excellent productivity.

Explanatory drawing of the surface modification method of the 1st electrode surface which concerns on 1st Embodiment. Explanatory drawing of the industrial inkjet drawing apparatus which can be used for application | coating of the sol-gel liquid which concerns on 1st Embodiment. Explanatory drawing of the reflectance of the material which can be used for the 1st electrode which concerns on 1st Embodiment. 3 is a flowchart illustrating a method for manufacturing the electromechanical conversion film according to the first embodiment. Explanatory drawing of the manufacturing process of the electromechanical conversion film which concerns on 1st Embodiment. Explanatory drawing of the structure of the liquid discharge head which concerns on 3rd Embodiment. Explanatory drawing of the structure of the liquid discharge head which concerns on 3rd Embodiment. FIG. 10 is an explanatory perspective view of a configuration of an ink jet printer according to a fourth embodiment. Side surface explanatory drawing of the mechanism part of the inkjet printer which concerns on 4th Embodiment. Explanatory drawing of a structure of the deflection | deviation mirror which concerns on 5th Embodiment. Cross-sectional explanatory drawing of the structure of the acceleration sensor which concerns on 6th Embodiment. FIG. 10 is an explanatory perspective view of a configuration of a fine adjustment device for an HDD head according to a seventh embodiment. Sectional explanatory drawing of the structure of the ferroelectric memory element which concerns on 8th Embodiment. The perspective explanatory view of the composition of the angular velocity sensor concerning a 9th embodiment. The perspective explanatory view of the composition of the micropump concerning a 10th embodiment. Cross-sectional explanatory drawing of the structure of the microvalve which concerns on 11th Embodiment. FIG. 3 is an explanatory diagram of a PZT electro-mechanical conversion film pattern formed by an inkjet method in Example 1. 3 is a PE hysteresis curve of the electromechanical conversion element according to Example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

[First Embodiment]
In the present embodiment, a method for manufacturing an electro-mechanical conversion film will be described.

  The manufacturing method of the electro-mechanical conversion film of this embodiment includes a coating process, a drying process, a thermal decomposition process, and a crystallization process.

  Hereinafter, each process will be described.

  First, the coating process will be described.

  In the coating process, a sol-gel liquid, which is a precursor of an electromechanical conversion film, is partially applied to the surface of the first electrode provided on the substrate by an ink jet method according to the pattern of the target electromechanical conversion film. And forming a patterned sol-gel film.

  A method of partially applying the sol-gel liquid by the ink jet method is not particularly limited, and the sol-gel liquid can be directly applied on the first electrode by the ink jet method without performing a pretreatment process. However, in order to prevent the formation of a fine pattern and to prevent the sol-gel solution from adhering to a portion other than the target, it is preferable to perform a pretreatment step before applying the sol-gel solution.

  Examples of the pretreatment step include a step of partially modifying the surface of the first electrode provided on the substrate, and the surface property is controlled to control the wettability of the first electrode surface. It is preferable that

  By performing the pretreatment step, the surface energy contrast can be provided on the surface of the first electrode, and when the sol-gel solution is applied, the sol-gel solution is spread only in the hydrophilic region. It can be easily applied separately. That is, when the sol-gel solution is applied to the first electrode surface, it can be easily applied only to a desired place.

  Therefore, for example, it is preferable to perform surface modification on the surface of the first electrode in advance according to the shape of the sol-gel film to be formed. In this case, as the portion for surface modification, either the portion that forms the sol-gel film or the portion that does not form the sol-gel film may be surface modified, depending on the surface characteristics after the surface modification. You can choose.

  As a method for controlling the wettability of the first electrode surface, for example, a hydrophobic or hydrophilic liquid or a film can be applied to the first electrode surface, or a film can be formed.

  Specifically, for example, a method utilizing the phenomenon of self-arrangement on a specific metal of alkanethiol shown below can be mentioned.

  A specific operation example will be described with reference to FIG. FIG. 1 is an explanatory diagram of a surface modification method for a first electrode surface according to the first embodiment.

  Alkanethiol is a SAM (Self-Assembled Monolayer) on the surface of a metal such as gold (Au), silver (Ag), platinum (Pt), or a metal oxide such as copper (Cu) or nickel (Ni). It has the property of forming a self-assembled monomolecular film. For this reason, a substrate on which a first electrode 32 made of these metals or an alloy thereof is formed is prepared (FIG. 1A).

  Then, when the SAM treatment is performed by dipping the substrate 31 on which the first electrode 32 is formed into the alkanethiol solution, a SAM film 33 is formed on the surface of the first electrode 32 (FIG. 1B). Since an alkyl group is arranged in the SAM film 33, the entire surface of the first electrode 32 on the substrate 31 becomes hydrophobic.

  Next, a mask having a predetermined opening is formed on the substrate 31 on which the SAM film 33 is formed by photolithography using a photoresist 34 and a photomask 35. Thereafter, the SAM film 33 is patterned in accordance with the desired shape of the electromechanical conversion film by an etching process (FIG. 1C). At this time, the SAM film 33 can be etched by, for example, irradiating oxygen plasma, UV light, or the like.

  In the region where the resist film remains in the photolithography process, the patterned SAM film 33 remains even after the resist is peeled off, and the hydrophobicity is maintained. On the other hand, the resist-removed region in the photolithography process becomes hydrophilic because the SAM film 33 on the surface of the first electrode 32 is removed by the etching process (FIG. 1D).

  As described above, by performing the pretreatment step, the surface of the first electrode can be partially modified, and the first sol-gel solution can be easily and accurately targeted. It becomes possible to apply to the part of the electrode surface.

  In addition, as a pre-processing process, it is not limited to this, For example, it can also be set as the following modifications.

  In this modification, lanthanum nickelate (LNO) is used as the first electrode formed on the substrate. In this case, a Pt film is formed in advance under the LNO film. By patterning the LNO film into an electro-mechanical conversion film shape in advance by a photolithography process and an etching process, both a region where the LNO film is removed and the Pt film is exposed and a region where the LNO film remains are formed.

  When this substrate is SAM-treated (dip the substrate together with the alkanethiol solution), the SAM film is formed only on the Pt film and becomes water repellent, while the SAM film is not formed on the LNO and becomes hydrophilic. Therefore, the sol-gel liquid can be separately applied by the ink jet method.

  Next, an apparatus that can be suitably used in the coating process will be described with reference to FIG. FIG. 2 is an explanatory diagram of an industrial inkjet drawing apparatus that can be used for application of the sol-gel solution according to the first embodiment.

  For application of the sol-gel liquid by the ink jet method, for example, an industrial ink jet drawing apparatus 40 as shown in FIG. 2 can be used.

  The industrial inkjet drawing apparatus 40 shown in FIG. 2 is provided with a stage 43 that fixes a substrate 42 that is an object to which a sol-gel solution is applied on a gantry 41. Y-axis driving means 44 that can be moved in the direction is provided.

  Then, the sol-gel solution is applied to the substrate 42 by an inkjet head 45 provided so as to face the substrate 42, connected to the sol-gel solution supply pipe 46, and a control unit (not shown). The sol-gel solution is supplied and applied to the substrate in response to a signal from.

  The inkjet head 45 is fixed to the head base 47, and the head base 47 is connected to the X-axis drive means 49 provided on the X-axis support member 48, and can be moved in the X-axis direction. ing. For this reason, the inkjet head 45 can be moved to a desired position on the substrate 42 together with the Y-axis driving means 44 provided on the gantry side.

  With the industrial ink jet drawing apparatus as described above, the sol-gel liquid is landed only on the electro-mechanical conversion film pattern formation portion from the ink jet head based on the pattern of the electro-mechanical conversion film input in advance to the control unit. And can be applied.

  In addition, as a sol-gel liquid used by this embodiment, it is preferable to adjust the viscosity and the surface tension beforehand so that it can apply | coat with an inkjet head. The film thickness obtained by one film formation is preferably about 50 to 100 nm, and the sol-gel solution concentration is preferably optimized from the relationship between the film formation area and the amount of sol-gel liquid applied.

  The material of the sol-gel liquid is not particularly limited as long as it is a material that exhibits piezoelectric characteristics after film formation. Specifically, a material that becomes PZT upon film formation, lead lanthanum zirconate titanate (PLZT), lead magnesium niobate (PMN), lead nickel niobate (PNN), barium titanate (BT), etc. The raw material solution used as various piezoelectric ceramic materials can be used.

In addition, PZT here is a solid solution of lead zirconate (PbZrO ₃ ) and lead titanate (PbTiO ₃ ), and the characteristics differ depending on the ratio, but the ratio is not limited and is required. It can be selected according to the piezoelectric performance or the like. Among them, the ratio (molar ratio) of PbZrO ₃ and PbTiO ₃ is 53:47, and it is expressed by the chemical formula PZT (PZT (53/47)) represented by Pb (Zr _0.53 , Ti _0.47 ) O _3. Can be preferably used because it exhibits particularly excellent piezoelectric characteristics.

  Next, the drying process will be described.

  A drying process is a process of drying a sol-gel film by heat-processing a sol-gel film.

  When the sol-gel liquid is applied by an ink jet method, since the amount of the applied sol-gel liquid is small, a so-called coffee stain phenomenon is likely to occur in the drying process. This is a phenomenon in which extreme film thickness unevenness occurs at the end and the center of the electro-mechanical conversion film pattern. In the drying process of the sol-gel film, a solute concentration deviation occurs in the sol-gel film, This is thought to occur because the vapor concentration of the solvent is low at the end of the pattern.

  When the second electrode is formed on the electro-mechanical conversion film in which this phenomenon occurs to form an electro-mechanical conversion element, there may be a problem in the electrical characteristics of the electro-mechanical conversion element.

  In order to suppress the occurrence of the coffee stain phenomenon, it is preferable not to raise the temperature rapidly during heating during drying. Specifically, it is preferable that the sol-gel film applied by the ink jet method is heated and dried by raising the temperature by 25% or less of the boiling point of the main solvent constituting the sol-gel liquid per minute from room temperature. Thereby, the vapor concentration distribution of the solvent can be reduced in the sol-gel film formation region, and a good firing state can be obtained during the heat treatment. That is, variations in film thickness due to non-uniform drying are suppressed, and the occurrence of the coffee stain phenomenon can be suppressed.

  Here, the main solvent means a solvent having the largest content when the volume is used as a reference among the solvents contained in the sol-gel solution.

  The drying temperature in the drying step and the holding time after reaching the drying temperature are not particularly limited, and a drying temperature and a holding time that can sufficiently remove the solvent contained in the sol-gel liquid are selected. That's fine. For example, the drying temperature should just be about 80 to 250 degreeC which is the boiling point of alcohol used as a main solvent of a general sol-gel liquid. Further, when the solvent can be sufficiently removed only by the temperature raising process, it is not necessary to maintain the temperature after reaching the temporary temperature and the final temperature.

  As a means for drying the sol-gel film, any heating mechanism capable of controlling the drying temperature, the temperature rising rate, and the time, such as a hot plate or an infrared lamp irradiation device, may be used.

  Next, a thermal decomposition process and a crystallization process are demonstrated.

  The thermal decomposition step is a step of thermally decomposing the sol-gel film, and is a step of removing an organic substance in the sol-gel film from which the solvent component has been removed to form a pattern of an electro-mechanical conversion film such as PZT. .

  The crystallization step is a step of crystallizing the sol-gel film, and is a step of sintering and crystallizing the thermally decomposed electro-mechanical conversion film at a higher temperature.

  And it is the characteristics of this invention to thermally decompose and crystallize a sol-gel film | membrane by performing flash lamp irradiation in a thermal decomposition process and a crystallization process.

  By performing flash lamp irradiation on the sol-gel film in the pyrolysis process and the crystallization process, the sol-gel film can be changed to an electro-mechanical conversion film having piezoelectric performance, which is sufficient as a piezoelectric body. It becomes possible to demonstrate the performance.

  In addition, it is preferable to implement both a thermal decomposition process and a crystallization process.

  Further, the thermal decomposition step and the crystallization step may be continued from the drying step or may be performed after cooling once after the drying step.

  Next, the heating (annealing) process by flash lamp irradiation will be described in detail.

  As the flash lamp, for example, a lamp in which a rare gas such as xenon gas is enclosed and instantaneous irradiation is performed by strobe light emission or flash light emission can be used. In irradiation with a flash lamp, light having a wavelength from UV light to visible light is emitted, so that the light can be concentrated and rapidly heated on the surface of the substrate, which is the object. That is, since only the surface of the substrate is instantaneously heated, damage to the substrate due to heat can be suppressed.

  The irradiation energy of the flash lamp can be adjusted by controlling the irradiation time, the irradiation light power, and the pulse width of the irradiation light. For example, the irradiation energy of the flash lamp can be increased by increasing the irradiation time and the irradiation light power. Moreover, since a pulse will be continued when a pulse width is lengthened, the heating depth from the outermost surface of a target object can be enlarged. On the other hand, if the pulse width is shortened, only the outermost surface can be heated, and damage on the back side of the substrate can be extremely reduced.

  This feature can exert a great effect in the production of an electro-mechanical conversion film by an ink jet method. For example, there are two regions, a region where a sol-gel film applied by an inkjet method is formed on a substrate and a region where a sol-gel film is not formed, that is, a region where the first electrode is exposed. The case where it exists is demonstrated.

  The sol-gel film applied by the ink jet system is in a gel state by removing the solvent component of the sol-gel film through a drying process. A solid organic substance remains in the sol-gel film in a gel state, and the irradiation light is absorbed on the surface of the sol-gel film during flash lamp irradiation. Therefore, the sol-gel film can be rapidly and instantaneously heated from the sol-gel film surface, and thermal decomposition can be performed.

  Furthermore, by adjusting the irradiation time, power, and pulse width of the flash lamp, not only thermal decomposition but also crystallization can be performed continuously, so that an electro-mechanical conversion film can be formed efficiently in terms of process. Is possible.

  On the other hand, the region where the sol-gel film is not formed is formed from a noble metal such as Au, Ag, Pt, a metal such as Cu, Ni, or a metal oxide thereof because surface modification with an alkanethiol solution is performed as described above. Has been. Further, at the time of applying the sol-gel liquid by the ink jet method, the SAM film is formed on the first electrode by the surface modification described above, and the SAM film is retained even after the sol-gel film drying process.

  Moreover, as shown in FIG. 3, since all the metals which comprise a 1st electrode have high reflectance, irradiation light is hard to be absorbed. In particular, in the wavelength range of 400 nm or more, the reflectance is 40% to 90%, and the surface of the first electrode is hardly heated by instantaneous irradiation.

  For this reason, thermal damage to the adhesion layer under the first electrode and the substrate itself can be minimized. As a result, not only Si wafers and glass plates but also thin film SUS plates, plastic films, flexible substrates, and the like are used as substrates, and thermal damage is not caused. Electro-mechanical conversion films can be formed on these substrates. It becomes possible. That is, the electro-mechanical conversion film can be manufactured without being limited to the substrate material.

  In addition, since the surface of the first electrode is hardly heated by the instantaneous flash lamp irradiation, the SAM film on the first electrode formed before applying the sol-gel liquid by the ink jet method is not lost, and the first electrode The water repellency of one electrode surface can be maintained. For this reason, as will be described later, when the above-described steps are repeated until a desired film thickness is obtained, the pre-treatment step is not required in the formation of the second and subsequent electro-mechanical conversion films, and the productivity is improved. be able to.

  In the thermal decomposition step and the crystallization step, the flash lamp irradiation time is preferably 1 sec or less. The amount of energy accumulated by flash lamp irradiation depends on the irradiation power and time, but even in the case of flash lamp irradiation with low irradiation intensity, if the irradiation time is 1 sec or less, the influence of the temperature rise of the substrate due to heating is reduced. be able to. For this reason, the substrate is not thermally damaged. Furthermore, the SAM film formed on the first electrode surface does not disappear, and the water repellency of the first electrode surface can be maintained.

  In addition, since the crystallinity and orientation when the electro-mechanical conversion film that is the heating object is crystallized can be easily controlled, the irradiation time of the flash lamp is more preferably 10 msec or more and 800 msec or less. .

  When the irradiation time of the flash lamp is longer than 1 sec, the temperature of the first electrode surface on the substrate rises due to the heat storage / heat transfer effect of the substrate. In particular, when the temperature of the first electrode surface is 300 ° C. or higher, the SAM film formed on the first electrode surface disappears due to the surface modification performed before the coating step. That is, the state on the surface of the first electrode changes from water repellency to hydrophilicity. For this reason, in the formation of the electromechanical conversion film for the second and subsequent times, it is necessary to perform the pretreatment step again before the coating step. As a result, the number of steps in the method for producing an electro-mechanical conversion film increases, which is inefficient in terms of productivity.

  Further, when a thin film SUS plate, a plastic film, a flexible substrate, or the like is used as a substrate, the substrate itself is damaged due to the effect of temperature rise due to heating. For this reason, it becomes difficult to form an electro-mechanical conversion film on the substrate, and an electro-mechanical conversion element cannot be formed.

  The electro-mechanical conversion film can be formed by the above-described process, but the target film thickness may not be obtained with the electro-mechanical conversion film prepared by applying the droplet once by the inkjet method. is there.

  In this case, an electro-mechanical conversion film having a desired film thickness can be obtained by repeatedly performing the above-described method for producing an electro-mechanical conversion film. In addition, when repeating the manufacturing method of the above-mentioned electromechanical conversion film | membrane, the process and combination to repeat can be selected arbitrarily.

  Hereinafter, steps and combinations for repeating the above-described method for producing an electromechanical conversion film will be described with reference to FIG.

  FIG. 4 is a flowchart illustrating the method for manufacturing the electro-mechanical conversion film according to the first embodiment. Specifically, FIG. 4 is a diagram illustrating an example of an operation flow in the case of repeatedly producing the electromechanical conversion film. In FIG. 4, the arrows (a), (b), and (c) mean repetition of steps, and can be repeated arbitrarily and at arbitrary timing as described below. In the operation flow shown in FIG. 4, the process of preparing the substrate provided with the first electrode is described as the starting point, and the point where the electro-mechanical conversion film forming process is completed is described as the ending point. .

  As a first example, repetition may be performed at an arbitrary timing after the drying step, the thermal decomposition step, and the crystallization step.

  Only the coating process and the drying process are repeatedly laminated a predetermined number of times (arrows in FIG. 4A). And a thermal decomposition process can be performed at arbitrary timing, and a crystallization process can be performed. Depending on the case, after that, it is possible to return to the coating step and the drying step, repeatedly form a film, and stack (arrows in FIG. 4C).

  As a modification thereof, the coating process, the drying process, and the thermal decomposition process are repeated a predetermined number of times (arrows in FIG. 4B). And a crystallization process can be performed at arbitrary timings. Depending on the case, after that, there may be mentioned a method of returning to the coating step, the drying step and the thermal decomposition step and repeatedly forming and laminating (arrows in FIG. 4C).

  As a second example, there is a method in which a coating process, a drying process, a thermal decomposition process, and a crystallization process are repeated in this order to form a film and stack it (arrow (c) in FIG. 4).

  As described above, before the first coating step, SAM treatment is performed by dipping each substrate into an alkanethiol solution, and the first electrode outside the pattern formation region of the desired electro-mechanical conversion film is formed on the first electrode. Water repellency is achieved by forming a SAM film.

  After the coating process, the substrate is formed on the first electrode layer because it undergoes a drying process and a thermal decomposition and crystallization process by irradiation with a flash lamp, so that the substrate is hardly or hardly damaged. The SAM film is retained. That is, the water repellency is maintained on the first electrode even after the thermal decomposition and crystallization treatment of the sol-gel film by flash lamp irradiation. For this reason, the pretreatment process before the second and subsequent coating processes can be omitted, and the process can be simplified.

  This will be specifically described with reference to FIG. FIG. 5 is an explanatory diagram of the manufacturing process of the electromechanical conversion film according to the first embodiment.

  FIG. 5D shows the same state as in FIG. That is, the SAM film 33 having an opening is formed on the first electrode 32 provided on the substrate 31, and the first region 50 where the SAM film 33 is not formed is hydrophilic. The second region 51 where the SAM film 33 is formed exhibits hydrophobicity.

  Next, in FIG. 5E, a coating process is performed in which a sol-gel solution is partially coated by an ink jet method to form a patterned sol-gel film 53. In FIG. 5E, the sol-gel liquid 53 is formed from the inkjet head 52 in the hydrophilic region, which is the first region 50 where the SAM film 33 is not formed.

  In FIG. 5F, a drying process for drying the formed sol-gel film 53, a thermal decomposition process for thermally decomposing the sol-gel film 53 by flash lamp irradiation, and a sol-gel film 53 by flash lamp irradiation. A crystallization step of crystallizing. At this time, the sol-gel film 53 becomes the electro-mechanical conversion film 54 and the SAM film 33 is held without disappearing.

  And FIG.5 (D ')-(F') has shown a mode that the application | coating process, a drying process, a thermal decomposition process, and a crystallization process are performed repeatedly. That is, the sol-gel film 53 ′ is formed by the coating process on the electro-mechanical conversion film 54 formed by the first coating process, drying process, thermal decomposition process, and crystallization process, and then the drying process and thermal decomposition process. Then, the electromechanical conversion film 54 ′ is formed by the crystallization process.

  At this time, the SAM film 33 is held outside the region where the electromechanical conversion film 54 is formed, that is, in the second region 51. For this reason, the electromechanical conversion film 54 ′ is formed without performing the process of forming the SAM film 33 as an example of the pretreatment process shown in FIG. 1B and the process of patterning the SAM film shown in FIG. Can be repeatedly laminated.

  That is, as shown in FIGS. 5 (E ′) and (F ′), the electro-mechanical conversion film 54 ′ can be repeatedly stacked in the same manner as in the steps of FIGS. 5 (E) and (F). . In addition, when performing repeatedly, what is necessary is just to repeat FIG.5 (D ')-(F') predetermined times.

  The electro-mechanical conversion film can be formed to a thickness of 5 μm by repeatedly forming and laminating the electro-mechanical conversion film by the method described above.

  Even when the electro-mechanical conversion film is repeatedly formed, in the drying step, the temperature is raised by 25% or less of the boiling point of the main solvent constituting the sol-gel liquid, and dried by heating, as in the first time. Is preferred.

  Thereby, the vapor concentration distribution of the solvent is reduced in the sol-gel film formation region, the occurrence of the coffee stain phenomenon is suppressed, and the variation in the film thickness due to non-uniform drying is suppressed. For this reason, it becomes possible to suppress film thickness unevenness of the electromechanical conversion film. As a result, the electromechanical conversion film formed by repeating the above process also has a desired shape, and a high-quality device with good electrical characteristics can be provided.

  As mentioned above, according to the manufacturing method of the electromechanical conversion film which concerns on 1st Embodiment, the thermal decomposition process of thermally decomposing a sol-gel film by performing flash lamp irradiation to a sol-gel film, and a sol-gel film And a crystallization step of crystallizing the sol-gel film by performing flash lamp irradiation. For this reason, the thermal damage to the board | substrate in a thermal decomposition process and a crystallization process can be suppressed. As a result, it is possible to manufacture an electro-mechanical conversion film that is not limited to the substrate material and has excellent productivity.

[Second Embodiment]
In the present embodiment, a method for manufacturing an electro-mechanical conversion element will be described.

  As a method for manufacturing the electro-mechanical conversion element of the present embodiment, a second electrode is further disposed on the electro-mechanical conversion film obtained by the method for manufacturing the electro-mechanical conversion film described in the first embodiment. It has the process, It is characterized by the above-mentioned.

  The step of disposing the second electrode on the electro-mechanical conversion film is not particularly limited and can be formed by a sputtering method or the like.

  Further, the material of the second electrode is not particularly limited, and the second electrode can be made of the same material as that of the first electrode, or can be made of a different material. Specifically, for example, a platinum group metal such as platinum or an alloy thereof, or a conductive oxide, for example, can be used.

  The electro-mechanical conversion element obtained by the above manufacturing method can provide a high-quality device having good electrical characteristics because the film thickness unevenness of the electro-mechanical conversion film is suppressed.

[Third Embodiment]
In this embodiment, a configuration example of a liquid discharge head including an electro-mechanical conversion element obtained by the method for manufacturing an electro-mechanical conversion element described in the second embodiment will be described with reference to FIGS. explain.

  FIG. 6 is a schematic diagram showing an example of the configuration of a one-nozzle liquid discharge head 60, and FIG. 7 is a liquid discharge head 67 formed by arranging a plurality of the one-nozzle liquid discharge heads 60 shown in FIG. It is the schematic of an example of the structure of.

  6 and 7 includes a nozzle that discharges droplets, a pressurizing chamber (pressure chamber) that communicates with the nozzle, a diaphragm that forms part of the wall of the pressurizing chamber, A liquid discharge head including the electromechanical conversion element described in the second embodiment.

  The configuration of the liquid discharge head 60 will be specifically described with reference to FIG.

  The discharge driving means for boosting the liquid in the pressurizing chamber 61 is constituted by a diaphragm 65 that constitutes a part of the wall of the pressurizing chamber 61, and an electro-mechanical conversion element 66 is disposed on the diaphragm 65. In addition, a pressurizing chamber 61 that is an ink chamber that is formed by etching the substrate 64 on which the electro-mechanical conversion element 66 is formed and stores a liquid such as ink (hereinafter referred to as “ink”), and the pressurizing chamber 61. It has a nozzle plate 63 as an ink nozzle provided with a nozzle 62 as a nozzle hole as an ink discharge port for discharging the ink in the form of droplets.

  The mechanism by which the liquid discharge head 60 discharges droplets is that stress is generated in the electromechanical conversion film 662 by supplying power to the first electrode (lower electrode) 661 and the second electrode (upper electrode) 663. Thus, the diaphragm 65 is vibrated. Along with this vibration, the ink in the pressurizing chamber 61 is ejected from the nozzle 62 in the form of droplets. Note that illustration and description of liquid supply means, which is ink supply means for supplying ink into the pressurizing chamber 61, ink flow paths, and fluid resistance are omitted.

  According to the liquid discharge head, since the electro-mechanical conversion element having excellent electrical characteristics is suppressed and the unevenness of the thickness of the electro-mechanical conversion film described in the second embodiment is suppressed, ink droplet discharge failure is caused. And stable ink droplet ejection characteristics can be obtained.

  In addition, the electromechanical conversion element has a simple structure (and has performance equivalent to that of bulk ceramics), and further has an etching removal from the back surface for forming the pressure chamber and a nozzle hole. By joining the nozzle plates, a liquid discharge head can be easily obtained.

[Fourth Embodiment]
In the present embodiment, a configuration example of an ink jet printer including the liquid ejection head described in the third embodiment will be described with reference to FIGS. 8 and 9.

  FIG. 8 is an explanatory perspective view of the configuration of the ink jet printer according to the present embodiment, and FIG. 9 is a side explanatory view of a mechanism part of the ink jet printer according to the present embodiment.

  The ink jet printer 70 includes a carriage 71 that can move in the main scanning direction inside the main body of the recording apparatus, a recording head composed of an ink jet head that implements the present invention mounted on the carriage 71, an ink cartridge 72 that supplies ink to the recording head, and the like. A printing mechanism 73 and the like are housed, and a paper feed cassette (or a paper feed tray) 75 capable of stacking a large number of sheets 74 from the front side is detachably attached to the lower part of the recording apparatus main body. can do. Further, the manual feed tray 76 for manually feeding the paper 74 can be opened, the paper 74 fed from the paper feed cassette 75 or the manual feed tray 76 is taken in, and a required image is displayed by the printing mechanism unit 73. After recording, the paper is discharged onto a paper discharge tray 77 mounted on the rear side.

  The printing mechanism 73 holds a carriage 71 slidably in the main scanning direction by a main guide rod 78 and a sub guide rod 79 which are guide members horizontally mounted on left and right side plates (not shown). The head 80 composed of the liquid discharge head described in the third embodiment for discharging ink droplets of each color of (Y), cyan (C), magenta (M), and black (Bk) has a plurality of ink discharge ports (nozzles). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward. Further, each ink cartridge 72 for supplying ink of each color to the head 80 is replaceably mounted on the carriage 71.

  The ink cartridge 72 has an air opening communicating with the atmosphere upward, a supply opening for supplying ink to the head 80 below, and a porous body filled with ink inside, and the capillary force of the porous body. Thus, the ink supplied to the liquid discharge head (head) is maintained at a slight negative pressure. Further, although the heads 80 of the respective colors are used here as the recording heads, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

  Here, the carriage 71 is slidably fitted to the main guide rod 78 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 79 on the front side (upstream side in the paper conveyance direction). doing. In order to move and scan the carriage 71 in the main scanning direction, a timing belt 84 is stretched between a driving pulley 82 and a driven pulley 83 that are rotationally driven by a main scanning motor 81, and the timing belt 84 is fixed to the carriage 71. doing. Then, the carriage 71 is reciprocated by forward and reverse rotation of the main scanning motor 81.

  On the other hand, in order to convey the paper 74 set in the paper feed cassette 75 to the lower side of the head 80, the paper 74 is guided from the paper feed cassette 75 to the paper feed roller 85 and the friction pad 86 for separating and feeding the paper 74. A guide member 87, a transport roller 88 that reverses and transports the fed paper 74, a transport roller 89 that is pressed against the peripheral surface of the transport roller 88, and a tip that defines the feed angle of the paper 74 from the transport roller 88 A roller 90 is provided. The transport roller 88 is rotationally driven by a sub-scanning motor 91 through a gear train.

  A printing receiving member 92 is provided as a paper guide member for guiding the paper 74 fed from the transport roller 88 below the head 80 corresponding to the movement range of the carriage 71 in the main scanning direction. On the downstream side of the printing receiving member 92 in the paper conveyance direction, a conveyance roller 93 and a spur 94 that are rotationally driven to send the paper 74 in the paper discharge direction, and a paper discharge roller 95 that sends the paper 74 to the paper discharge tray 77. In addition, a spur 96 and guide members 97 and 98 that form a paper discharge path are disposed.

  At the time of recording, the head 80 is driven according to the image signal while moving the carriage 71, thereby ejecting ink onto the stopped paper 74 to record one line. Records lines. Upon receiving a recording end signal or a signal that the trailing edge of the paper 74 has reached the recording area, the recording operation is terminated and the paper 74 is discharged.

  In FIG. 8, a recovery device 99 for recovering the ejection failure of the head 80 is disposed at a position outside the recording area on the right end side in the moving direction of the carriage 71. The recovery device 99 includes a cap unit, a suction unit, and a cleaning unit. The carriage 71 is moved to the recovery device 99 side during printing standby, and the head 80 is capped by the capping means, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is 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 a discharge failure occurs, the discharge port (nozzle) of the head 80 is sealed with a capping unit, and bubbles and the like are sucked out from the discharge port with the suction unit through the tube. Is removed by the cleaning means to recover the ejection failure. 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.

  The ink jet recording apparatus of this embodiment is equipped with the liquid discharge head (ink jet head) described in the third embodiment.

  As described above, the liquid discharge head uses an electro-mechanical conversion element that suppresses film thickness unevenness of the electro-mechanical conversion film of the electro-mechanical conversion element constituting the liquid discharge head and has good electrical characteristics. Therefore, there is no ink droplet ejection failure due to electromechanical conversion element diaphragm drive failure. For this reason, the ink jet recording apparatus of the present embodiment can obtain stable ink droplet ejection characteristics and can improve the image quality.

[Fifth Embodiment]
In the present embodiment, a configuration example of a polarizing mirror including an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described with reference to FIG.

  FIG. 10 is a perspective explanatory view of the configuration of the deflection mirror according to the present embodiment. Specifically, FIG. 10 is a perspective explanatory view of a piezoelectric MEMS (Micro Electro Mechanical Systems) mirror as a configuration example of a polarizing mirror.

  The piezoelectric MEMS mirror 200 includes a fixed base 201, a mirror part 202 having a reflective surface, an elastic support member 203 that supports the mirror part 202, and a beam-like member 204 that supports a part of the elastic support member 203 from both sides. Have And the electro-mechanical conversion element 205 fixed to the beam-like member 204 is included.

  In such a piezoelectric MEMS mirror 200, a voltage is applied to the electromechanical conversion element 205, and the drive unit 206 is distorted, so that the mirror unit 202 vibrates.

  As the electro-mechanical conversion film of the electro-mechanical conversion element of the piezoelectric MEMS mirror 200, the electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method according to the first embodiment is applied. Thus, the performance of the piezoelectric MEMS mirror 200 can be improved.

[Sixth Embodiment]
In the present embodiment, a configuration example of an acceleration sensor including an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described with reference to FIG.

  FIG. 11 is a cross-sectional explanatory view of the acceleration sensor according to the present embodiment.

  The acceleration sensor 210 includes a silicon substrate 211 having a thick part X and a thin part Y, anisotropic etching on one surface, and glass substrates 212A and 212B sandwiching the silicon substrate 211. Furthermore, an electro-mechanical conversion element 213 formed on the thin portion Y of the silicon substrate 211 and including an upper electrode 2131, an electro-mechanical conversion film 2132, and a lower electrode 2133 is included.

  When acceleration is applied to the acceleration sensor 210, the electromechanical conversion element 213 is deformed together with the thick portion X. The acceleration sensor 210 detects the acceleration by converting the amount of displacement of the electromechanical conversion element 213 into a voltage.

  By applying the electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method of the first embodiment to such an acceleration sensor 210, the performance of the acceleration sensor 210 can be improved.

[Seventh Embodiment]
In this embodiment, a configuration example of a fine adjustment device for an HDD (Hard Disk Drive) head provided with an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described. This will be described with reference to FIG.

  FIG. 12 is an explanatory perspective view of the configuration of the HDD head fine adjustment device 220 according to the present embodiment.

  The HDD head fine adjustment device 220 includes a movable access arm 221, a head 224 attached to the tip of a support spring 223 via a central member 222, an electro-mechanical conversion element 225 A attached to the central member 222, 225B. The HDD head fine adjustment device 220 performs fine adjustment by moving the head 224 to a predetermined position on the HDD by alternately expanding and contracting the electromechanical conversion elements 225A and 225B.

  By applying the electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method of the first embodiment to the HDD head fine adjustment apparatus 220, the performance of the HDD head fine adjustment apparatus 220 can be improved. Enhanced.

[Eighth Embodiment]
In the present embodiment, a configuration example of a ferroelectric memory element including an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described with reference to FIG. To do.

  FIG. 13 is a cross-sectional explanatory view of the configuration of the ferroelectric memory element 230 according to the present embodiment.

  The ferroelectric memory device 230 has a substrate 233 on which a bit line 231 and a word line 232 are formed. Then, an interlayer insulating film 234 formed on the substrate 233 and an electro-mechanical conversion element 235 formed on the interlayer insulating film 234 and including an upper electrode 2351, an electro-mechanical conversion film 2352, and a lower electrode 2353 are provided. Furthermore, an interlayer insulating film 236 formed on the electromechanical conversion element 235 and a wiring 237 that is electrically connected to the upper electrode 2351 through a contact hole are included.

  The ferroelectric memory element 230 functions as a memory by utilizing reversal of remanent polarization of the electro-mechanical conversion film 2352 generated when a voltage is applied to the upper electrode 2351 and the lower electrode 2353.

  By applying the electro-mechanical conversion film obtained by the method of manufacturing the electro-mechanical conversion film of the first embodiment to such a ferroelectric memory element 230, the performance of the ferroelectric memory element 230 is improved. It is done.

[Ninth Embodiment]
In this embodiment, a configuration example of an angular velocity sensor including an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described with reference to FIG.

  FIG. 14 is an explanatory perspective view of the configuration of the angular velocity sensor according to the present embodiment. Specifically, FIG. 14 is an explanatory perspective view illustrating a vibration gyro-type angular velocity sensor 240 as a configuration example of the angular velocity sensor of the present embodiment.

  The vibration gyro-type angular velocity sensor 240 has a tuning fork 241 formed of a material with little thermal expansion. Then, an oscillation-driving electro-mechanical conversion element 242a and a detection electro-mechanical conversion element 242b attached to the tuning fork 241; a pad 243a corresponding to the electro-mechanical conversion element 242a; and an electro-mechanical conversion element 242b. And a pad 243b corresponding to.

  The electro-mechanical conversion element 242a and the electro-mechanical conversion element 242b are each formed on a vertical surface. The vibration gyro-type angular velocity sensor 240 detects vibration of the electro-mechanical conversion element 242b via the pad 243b, and detects the angular velocity based on the frequency difference.

  The electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method according to the first embodiment is applied to the electro-mechanical conversion film of the electro-mechanical conversion element of the vibration gyro type angular velocity sensor 240. By doing so, the performance of the vibration gyro-type angular velocity sensor 240 can be improved.

[Tenth embodiment]
In the present embodiment, a configuration example of a micropump having an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described with reference to FIG.

  FIG. 15 is a perspective explanatory view of the configuration of the micropump according to the present embodiment.

  The micropump 250 includes a substrate 252 on which a flow path 251 is formed, and a piezoelectric actuator 253 including a vibration plate 2531 and an electro-mechanical conversion element 2532 formed in close contact with the vibration plate 2531. Then, a flow path forming substrate 254 provided with a plurality of piezoelectric actuators 253, a lid substrate 255, and a protective substrate 256 are included. The micro pump 250 sequentially sucks or discharges the fluid by driving the diaphragm 2531 sequentially in the direction of the arrow in the drawing, and transports the fluid in the flow path 251. By devising the shapes of the liquid inflow hole and the outflow hole, or by providing a valve in the flow path 251, the transport efficiency can be increased.

  By applying the electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method of the first embodiment to the electro-mechanical conversion film of the electro-mechanical conversion element 2532 of the micropump 250 as described above. The performance of the micropump 250 can be improved.

[Eleventh embodiment]
In this embodiment, a configuration example of a microvalve having an electro-mechanical conversion film obtained by the method for manufacturing an electro-mechanical conversion film described in the first embodiment will be described.

  FIG. 16 is a cross-sectional explanatory diagram of the configuration of the microvalve according to the present embodiment.

  The microvalve 260 includes a disc-shaped substrate 262 having a discharge port 261 at the center, and a diaphragm 264 having a projection 263 serving as a valve at the center. And it includes a fixing portion 265 for fixing the substrate 262 and the diaphragm 264, an electro-mechanical conversion element 266 formed on the diaphragm 264, and an inlet 267 through which a fluid flows. The microvalve 260 controls the flow of fluid by opening and closing the discharge port 261 using the vibration of the protrusion 263 caused by the distortion of the electromechanical conversion element 266.

  By applying the electro-mechanical conversion film obtained by the electro-mechanical conversion film manufacturing method of the first embodiment to such a microvalve 260, the performance of the microvalve 260 can be enhanced.

The present invention will be described below with specific examples, but the present invention is not limited to these examples.
[Example 1]
In this example, an electromechanical conversion film and an electromechanical conversion element were formed by the following procedure, and the characteristics were evaluated.

  The manufacturing procedure will be described with reference to FIG. 1, FIG. 5 and FIG.

  First, as shown in FIG. 1A, a silicon substrate surface having a plate thickness of 625 μm was prepared by forming a first electrode (lower electrode) made of Pt by sputtering.

Next, as shown in FIG. 1B, a SAM film was formed on the entire surface of Pt on the silicon substrate. The SAM film was obtained by dipping the entire substrate in an alkanethiol solution and self-aligning it. As the alkanethiol solution, dodecanethiol CH ₃ (CH ₂ ) ₁₁ —SH was used, and ethanol having a molar concentration of 0.5 mmol / L was used as the solution.

  As shown in FIG. 1C, the SAM film for forming the electro-mechanical conversion film was removed, and the resist was patterned by photolithography to protect the necessary SAM film. At this time, patterning was performed so that the pattern 110 shown in FIG. 17 was obtained, and the SAM film was removed from the portion indicated by 111 in the figure to make it hydrophilic.

  And the SAM film | membrane of the part which forms an electro-mechanical conversion film | membrane pattern was removed by irradiating oxygen plasma to the substrate surface side from the board | substrate upper surface.

  Next, the resist was peeled off as shown in FIG. The contact angle of the SAM film formed by the steps so far with respect to pure water was 110 degrees, indicating hydrophobicity, and the contact angle of the Pt surface on the substrate from which the SAM film was removed was 10 degrees or less, indicating hydrophilicity.

  Next, FIG. 5 (E) shows a first region 50 which is a hydrophilic portion of the Pt surface formed on the silicon substrate formed in the above process by using a sol-gel solution which is a PZT precursor by an inkjet method. The step of applying is shown. In the inkjet method, the general industrial inkjet drawing apparatus shown in FIG. 2 was used.

  As the sol-gel solution used, lead acetate trihydrate, isopropoxide titanium and isopropoxide zirconium were used as starting materials. Crystallized lead acetate was dissolved in 2-methoxyethanol (boiling point: 124 ° C.), which is the main solvent, and then dehydrated.

  A sol-gel solution is synthesized by dissolving isopropoxide titanium and isopropoxide zirconium in methoxyethanol, proceeding with alcohol exchange reaction and esterification reaction, and mixing with 2-methoxyethanol solution in which lead acetate is dissolved. did.

  At this time, the above solutions are mixed so that the molar ratio of the metal species contained in the sol-gel solution is Pb: Zr: Ti = 100: 53: 47.

  Further, diethylene glycol monomethyl ether (boiling point: 194.1 ° C.) and 1-nonanol (boiling point: 213 ° C.) having a boiling point higher than that of methoxyethanol were added to the synthesized sol-gel solution.

  The PZT concentration in the sol-gel solution was adjusted to 0.1 mol / L so that the thickness of the electromechanical conversion film obtained by one film formation was about 80 nm to 90 nm.

  As shown in FIG. 17, the PZT electro-mechanical conversion film pattern 111 formed by the ink jet method was a long pattern having a width of 50 μm and a length of 1000 μm. Then, they were arranged at a 1: 1 pitch (the pattern width and the space width between the patterns were set to the same 50 μm) in the width direction (Y direction in FIG. 17).

  As shown in FIG. 5E, a sol-gel solution was applied to the surface of the first electrode by an industrial ink jet drawing apparatus. At this time, because of the contrast of the contact angle on the surface of the first electrode, the sol-gel solution spreads only in the first region 50 which is a hydrophilic portion and forms a pattern. This was performed by raising the temperature from room temperature to 124 ° C. by heating the bottom surface of the substrate with a hot plate in the drying step of drying the sol-gel film.

  The heating rate at this time was 30 ° C./min, and the heating rate per minute was 24% of the boiling point (124 ° C.) of methoxyethanol as the main solvent. After reaching 124 ° C., the temperature was kept for 1 minute, and the temperature was lowered to room temperature.

  After drying the sol-gel film, a pyrolysis process was performed in which an organic substance in the sol-gel film was pyrolyzed. In this example, in the thermal decomposition process, a xenon flash lamp having a radiation wavelength range of 240 nm to 2000 nm was used, and pulsed light having a frequency of 30 kHz was irradiated for 50 msec. Moreover, as the comparative example 1, the thermal decomposition process was implemented by heat-processing for 5 minutes at 500 degreeC with a hotplate. And about each of Example 1 and Comparative Example 1, the PZT electro-mechanical conversion film pattern as shown in FIG.5 (F) was obtained.

  And the contact angle with respect to the pure water of the 1st electrode surface in the board | substrate of Example 1 and Comparative Example 1 after performing the application | coating process, the drying process, and the thermal decomposition process once was evaluated.

  In the substrate of Example 1, the contact angle of the first electrode surface with pure water was 105 degrees, and the contact angle of the PZT surface with pure water was 25 degrees. In addition, the SAM film pattern remained on the first electrode surface outside the electro-mechanical conversion film pattern region.

  On the other hand, the contact angle with respect to pure water on the surface of the first electrode in the substrate of Comparative Example 1 was 40 degrees.

  Subsequently, as shown in FIG. 5 (E ′), the PZT electro-mechanical conversion film pattern formed for the first time was aligned, and the sol-gel solution was applied again by the industrial inkjet drawing apparatus of FIG. In addition, the surface treatment of the substrate was not performed before the application of the sol-gel solution.

  In the substrate of Example 1, the sol-gel liquid spread and spread only on the PZT electro-mechanical conversion film pattern due to the contact angle contrast. On the other hand, in the substrate of Comparative Example 1, the sol-gel liquid protrudes from the ridge line of the PZT electro-mechanical conversion film pattern and spreads on the first electrode surface outside the pattern region, so that a desired electro-mechanical conversion film pattern is obtained. Collapsed and could not be formed.

  In the substrate of Example 1, as shown in FIG. 6 (F ′), the same drying process and thermal decomposition process as the first time were carried out to obtain an overcoated PZT electro-mechanical conversion film. The conditions for the drying process and the thermal decomposition process were the same as the conditions for the drying process and the thermal decomposition process after the first coating process.

  Thereafter, the crystallization process was performed on the patterned PZT electromechanical conversion film obtained by repeating the above process four times, that is, six times in total. As the flash lamp in the crystallization process, the same xenon flash lamp as in the thermal decomposition process was used. Further, when the frequency was set to 30 kHz as in the thermal decomposition step and the irradiation time was set to 80 msec, defects such as cracks did not occur in the electromechanical conversion film. Further, the contact angle with pure water on the surface of the first electrode outside the PZT electro-mechanical conversion film pattern region was 105 degrees, and the hydrophobicity was maintained.

  Subsequently, the above process was further repeated 6 times to form an electromechanical conversion film. That is, the coating process, the drying process, and the thermal decomposition process were repeated six times. Subsequently, the crystallization process was performed again, but no defects such as cracks occurred in the PZT electromechanical conversion film. In this case as well, the conditions for the drying process and the thermal decomposition process were the same as the conditions for the drying process and the thermal decomposition process after the first coating process.

  Further, the electro-mechanical conversion film was repeatedly formed 6 times on the obtained electro-mechanical conversion film. That is, the coating process, the drying process, and the thermal decomposition process were repeated 6 times, and the cycle up to the subsequent crystallization process was performed again. Also in this case, the conditions for the drying process and the pyrolysis process were the same as the conditions for the drying and pyrolysis process after the first application.

  After completion of crystallization of the sol-gel film by the crystallization process, the film thickness of the electro-mechanical conversion film pattern was measured. As a result, the film thickness of the finally formed PZT electro-mechanical conversion film is 1.6 μm, and it is a good electro-mechanical system that does not suffer from defects such as pattern ridgeline collapse, film thickness unevenness in the pattern, and cracks. A conversion membrane was obtained.

  On the patterned electro-mechanical conversion film formed by the above steps, Pt as an example of the second electrode was formed by sputtering and patterned to produce an electro-mechanical conversion element. And the electrical property and electromechanical conversion ability (piezoelectric constant) of the produced electromechanical conversion element were evaluated.

  As a result, the dielectric constant of the electro-mechanical conversion film is 1700, the dielectric loss is 0.08, and the withstand voltage is 60 V, all of which show excellent electrical characteristics and sufficient to have a function as an electro-mechanical conversion film. Characteristics were obtained.

The electro-mechanical conversion film obtained from Example 1 has a remanent polarization of 19.3 μC / cm ² and a coercive electric field of 36.3 kV / cm, which is equivalent to that of a normal ceramic sintered body. I was able to confirm. The PE hysteresis curve at this time is shown in FIG.

Moreover, the electromechanical conversion ability was also evaluated. As an evaluation method, the amount of deformation by applying an electric field was measured with a laser Doppler vibrometer and calculated from fitting by simulation. As an evaluation result, the piezoelectric constant d ₃₁ of Example 1 was 134 to 145 pm / V, which was the same value as the ceramic sintered body. This is a characteristic value that can be sufficiently designed as a liquid discharge head.

  Further, an attempt was made to further increase the film thickness without arranging the second electrode (upper electrode). That is, crystallization treatment is performed for each pyrolysis treatment by flash lamp irradiation up to 6 times, and when this is repeated 10 times, a patterned PZT electro-mechanical conversion film of 5 μm is obtained without defects such as cracks. It was.

[Example 2]
In this example, a SUS plate having a thickness of 75 μm was used as the substrate, and Ni was deposited on the substrate as the first electrode. In other layer configurations, electro-mechanical conversion film pattern shapes, manufacturing process flow and conditions (surface treatment with alkanethiol liquid, patterning of water-repellent / hydrophilic regions, sol-gel liquid application by inkjet method, drying by hot plate) The conditions were the same as in Example 1.

  In addition, as conditions for flash lamp irradiation in the thermal decomposition step, pulsed light having a frequency of 3 kHz was used and the irradiation time was set to 500 msec. In addition, as a condition of flash lamp irradiation in the crystallization process, pulsed light having a frequency of 3 kHz was used and the irradiation time was set to 1.0 sec. For comparison, as Comparative Example 2, the irradiation time was set to 1.2 sec using pulsed light having a frequency of 3 kHz as the flash lamp irradiation condition in the crystallization process.

  As a result, in Example 2, the same electro-mechanical conversion film pattern as in Example 1 can be obtained, and after the second electrode film is formed, the electro-mechanical conversion having the same electro-mechanical conversion ability as in Example 1 is achieved. It functioned as an element. On the other hand, in Comparative Example 2, a desired pattern was obtained in the electro-mechanical conversion film formation by coating as in Example 2, but the substrate was warped during flash lamp irradiation in the first crystallization process. In other words, the SUS plate substrate was excessively heated by flash lamp irradiation, which caused thermal damage and deformed the substrate. As a result, the electro-mechanical conversion film cannot be further laminated and thickened.

  The electro-mechanical conversion film manufacturing method, electro-mechanical conversion element manufacturing method, liquid ejection head, ink jet printer, deflection mirror, acceleration sensor, HDD head fine adjustment device, ferroelectric memory element, angular velocity sensor, micro Although the pump and the microvalve have been described based on the embodiments and examples, the present invention is not limited to the above embodiments and examples, and various modifications and improvements can be made within the scope of the present invention.

31 Substrate 32 First electrode 53, 53 ′ Sol-gel film 54, 54 ′ Electro-mechanical conversion film 60, 67 Liquid discharge head 70 Inkjet printer 200 Piezoelectric MEMS mirror 210 Acceleration sensor 220 HDD head fine adjustment device 230 Strong Dielectric memory device 240 Angular velocity sensor 250 Micro pump 260 Micro valve

JP 2013-225671 A

Claims (4)

A coating step of partially applying a sol-gel liquid, which is a precursor of an electro-mechanical conversion film, to the surface of the first electrode provided on the substrate by an inkjet method to form a patterned sol-gel film; ,
A drying step of drying the sol-gel film;
A thermal decomposition step of thermally decomposing the sol-gel film by performing flash lamp irradiation on the sol-gel film;
A crystallization step of crystallizing the sol-gel film by irradiating the sol-gel film with a flash lamp.
A method for producing an electromechanical conversion film. In the thermal decomposition step and the crystallization step, the flash lamp irradiation time is 1 sec or less.
The method for producing an electro-mechanical conversion film according to claim 1.   A method for producing an electro-mechanical conversion film having an electro-mechanical conversion film having a desired film thickness by repeatedly performing the method for producing an electro-mechanical conversion film according to claim 1 or 2. A step of disposing a second electrode on the electro-mechanical conversion film manufactured by the method for manufacturing an electro-mechanical conversion film according to any one of claims 1 to 3;
A method for producing an electromechanical transducer.

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