JP2015032671A - Device for manufacturing electromechanical conversion element, method for manufacturing electromechanical conversion element, electromechanical conversion element, droplet discharge head, and droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for manufacturing an electromechanical conversion element, achieving corona polarization treatment in which variation of polarization is small, without damaging an electromechanical conversion element and a substrate or a substrate film.SOLUTION: In a device 10 for manufacturing an electromechanical conversion element, polarization treatment is performed to an electromechanical conversion element 20 having a structure where a first electrode, an electromechanical conversion film and a second electrode are laminated on a substrate 17 or a substrate film. The device includes a corona electrode 11 for generating electric charges by corona discharge, a stage 13 for installing the electromechanical conversion element 20 thereon, a grid electrode 12 disposed between the corona electrode 11 and the stage 13, and a heating mechanism for heating the electromechanical conversion element 20. The corona electrode 11 is an electrode having a planar shape and has a structure where a plurality of projecting tip parts 110 are formed on a facing surface facing the electromechanical conversion element 20.

Description

  The present invention relates to an electromechanical conversion element manufacturing apparatus, an electromechanical conversion element manufacturing method, an electromechanical conversion element, a droplet discharge head, and a droplet discharge apparatus.

  The electro-mechanical conversion element has a characteristic that its shape changes in accordance with an applied voltage. Conventionally, the electro-mechanical conversion element has been used in a droplet discharge head of an image forming apparatus and various applications by taking advantage of such a characteristic. Yes.

  As shown in FIG. 1A, the piezoelectric crystal included in the electro-mechanical conversion film constituting the electro-mechanical conversion element has a random polarization state immediately before voltage application. On the other hand, by repeating the voltage application, the piezoelectric crystal becomes an aggregate of domains in which the directions of polarization are aligned as shown in FIG.

  Thus, the displacement with respect to the drive voltage was not stable until the polarization directions of the piezoelectric crystals were aligned. For this reason, attempts have been made to align the direction of polarization in advance, and efforts have been made to stabilize the amount of displacement with respect to a predetermined drive voltage referred to as an aging process or a poling (polarization process) process.

  For example, first, a corona wire is disposed via a gap on a second surface of the piezoelectric body having electrodes formed on the first surface and facing the first surface. Then, there is known a polling treatment method for an inorganic piezoelectric material in which a voltage is applied between an electrode and a corona wire to supply electric charges to a second surface of the piezoelectric material to generate an electric field in the piezoelectric material ( For example, see Patent Document 1).

  However, when the polarization process is performed by the poling process method disclosed in Patent Document 1, when the piezoelectric body is formed on the substrate, cracks may occur in the piezoelectric body. Further, when the piezoelectric body is formed on the vibration plate (underlayer film), there is a case where the vibration plate is damaged if the polarization treatment is similarly performed sufficiently.

  Accordingly, an object of one embodiment of the present invention is to provide an electro-mechanical conversion element manufacturing apparatus that realizes corona polarization processing with little variation in polarization without damaging the electro-mechanical conversion element, the substrate, or the base film. There is to do.

  In view of the above problems, an electro-mechanical conversion element manufacturing apparatus according to one embodiment of the present invention has a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are stacked on a substrate or a base film. A device for manufacturing an electro-mechanical conversion element that performs polarization treatment on an electro-mechanical conversion element having a corona electrode that generates a charge by corona discharge, a stage on which the electro-mechanical conversion element is installed, and A grid electrode disposed between the corona electrode and the stage, and a heating mechanism for heating the electro-mechanical conversion element, the corona electrode having a planar shape, -It has the structure where the some point protrusion part was formed in the opposing surface facing a mechanical conversion element.

  According to one embodiment of the present invention, there is provided an electro-mechanical conversion element manufacturing apparatus that realizes corona polarization processing with little variation in polarization without damaging the electro-mechanical conversion element, the substrate, or the base film. be able to.

It is a schematic diagram which illustrates the change of the domain before and behind a polarization process. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration explanatory view showing an example of an electro-mechanical conversion element manufacturing apparatus according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration explanatory view showing an example of an electro-mechanical conversion element manufacturing apparatus according to a first embodiment of the present invention. It is explanatory drawing which illustrates the corona electrode of the manufacturing apparatus of an electromechanical conversion element. A shows an example of a corona electrode formed in a planar shape with the tips of the needle electrodes aligned. B shows an example of a corona electrode formed in a planar shape with the tips of the saw blade electrodes aligned. C shows an example of a corona electrode having a through hole between needle electrodes. It is explanatory drawing which shows an example of the manufacturing apparatus of the electromechanical conversion element which concerns on the 2nd Embodiment of this invention. It is composition explanatory drawing which shows an example of the manufacturing apparatus of the electromechanical conversion element which concerns on the 3rd Embodiment of this invention. It is explanatory drawing of a polarization process. It is explanatory drawing which shows the outline | summary of the electric charge amount accumulate | stored in an electromechanical conversion element. It is explanatory drawing of Pr and Pini. Explanatory drawing which shows the relationship between the crack generation rate and the polarizability which generate | occur | produced in the film | membrane when heating to 80 degreeC and performing a polarization process. It is a figure which illustrates the electromechanical conversion element which concerns on 4th Embodiment. It is a figure which illustrates the droplet discharge head which concerns on 5th Embodiment. It is a figure which illustrates the droplet discharge head which concerns on 5th Embodiment. It is a perspective view which illustrates the inkjet recording device which concerns on 6th Embodiment. It is a side view which illustrates the mechanism part of the inkjet recording device which concerns on 1st Embodiment. It is a table | surface which shows the polarization amount difference after a polarization process.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and the following embodiments are not departed from the scope of the present invention. Various modifications and substitutions can be made. Moreover, in each drawing, the same code | symbol is attached | subjected to the same component and the overlapping description may be abbreviate | omitted.

[First Embodiment]
The configuration of the electro-mechanical transducer manufacturing apparatus 10 according to the present embodiment will be described with reference to FIGS.
The electro-mechanical conversion element manufacturing apparatus 10 of the present embodiment includes an electro-mechanical conversion element 20 (a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are stacked on a substrate or a base film. Hereinafter, the electro-mechanical conversion element manufacturing apparatus 10 performs a polarization process on the piezoelectric element 20).

  As shown in FIGS. 2 and 3, the electro-mechanical conversion element manufacturing apparatus 10 includes a corona electrode 11 that generates electric charges by corona discharge, a stage 13 on which the electro-mechanical conversion element 20 is installed, and the corona electrode 11. And a grid electrode 12 arranged between the stage 13. Furthermore, it has a heating mechanism for heating the electromechanical conversion element 20 provided in the stage 13.

  The corona electrode 11 and the grid electrode 12 are connected to a corona electrode power source 14 and a grid electrode power source 15, respectively. At this time, as shown in FIG. 3, the other terminal not connected to each electrode of the corona electrode power supply 14 and the grid electrode power supply 15 is, for example, a place where the electromechanical conversion element 20 of the stage 13 is placed. Can be connected to. Further, when the ground wire 16 is connected to the stage 13, it can be connected to the ground wire 16.

  The stage 13 is configured such that a silicon wafer 17 can be placed on the upper surface thereof. As the silicon wafer to be subjected to the polarization treatment, a wafer in which the electromechanical conversion element 20 is formed in advance can be used. The layout of the electromechanical conversion element 20 can be arbitrarily set. Moreover, the structure of the electromechanical conversion element 20 is not specifically limited, For example, a bimorph structure, a unimorph structure, etc. may be sufficient.

  The corona electrode 11 faces the stage 13 and is formed via the grid electrode 12 therebetween. The corona electrode 11 is an electrode having a planar shape, and has a structure in which a pointed protrusion 110 is formed on a facing surface facing the electro-mechanical conversion element 20.

  The reason for forming the surface is that the electrode pad and the insulating film are formed in a fine pattern on the piezoelectric element 20, and in this configuration, an electric field is applied to the electro-mechanical conversion element through the electrode pad by corona charging, The polarization process is performed. In order to perform a uniform polarization process in a state where the electrode pad and the insulating film are mixed, it is preferable to arrange the tip protrusions at a high density.

  The size of the corona electrode 11 can be formed so as to be not less than an area 10 mm smaller than the outer periphery of the effective area of the electromechanical conversion element 20. For example, when the effective area of the electromechanical conversion element 20 is φ135 with respect to a 6-inch silicon wafer 17 (about φ150 mm), the corona electrode 11 can be formed to require an area of φ115 or more, for example. The plate thickness can be about 1 mm.

  The corona electrode 11 may be formed like a corona electrode 11-1 illustrated in FIG.

  The corona electrode 11-1 has a structure in which a plurality of needle electrodes 30 are arranged in the surface direction as pointed protrusions 110 on the facing surface facing the electro-mechanical conversion element 20. The tip positions on the side facing the conversion element 20 are aligned. A plurality of needle electrodes 30 are arranged in such a manner that the needle electrode 30 is orthogonal to the upper surface of the electro-mechanical conversion element 20 and the tip thereof faces the electro-mechanical conversion element 20. The reason why the tips of the needle electrodes 30 are aligned is to prevent the electric field intensity from changing and causing variations in polarization when the distance between the corona electrode 11 and the electromechanical conversion element 20 is different.

For example, the needle electrode 30 is preferably a φ2 mm tungsten needle, the tip is processed into a needle shape of R30 μm, and a plurality of processed tungsten needle electrodes 30 are preferably bundled to about φ160 mm. Electrode density, such as tungsten needles ten ^/ cm 2 can be about 50 present / cm ^2. More preferably, it is 25 / cm ² .

The corona electrode 11 may be formed like a corona electrode 11-2 illustrated in FIG.
The corona electrode 11-2 has a plurality of plate-like electrode plates 31 perpendicular to the facing surface as the tip protrusions 110 on the facing surface facing the electro-mechanical transducer 20, and the corona electrodes 11- It has the structure arrange | positioned mutually parallel toward 2 in-plane directions (YY direction). A saw blade electrode 32 having a saw blade shape is formed on the side of the electrode plate 31 facing the electromechanical conversion element 20. The saw blade electrode 32 is preferably formed by performing triangular unevenness processing at a pitch of 2 mm, for example. It is preferable that the above-mentioned electrode plates 31 are overlapped with the tip portions of the saw blade electrodes 32 between the adjacent electrode plates 31 being alternately shifted by 1 mm, for example.

  It is preferable to have a configuration in which the tip positions of the saw blade electrode 32 on the side facing the electro-mechanical conversion element 20 are aligned. Further, it is preferable that the upper surface of the electromechanical conversion element 20 and the tip surface of the saw blade electrode 32 are arranged in a parallel positional relationship.

As the electrode plate 31, for example, a tungsten electrode plate having a plate thickness of about 1 mm and a width of about 0.5 mm is preferably used, and the electrode density is, for example, about 10 sawtooth electrodes / cm ^{2 to} 100 pieces / cm ^2. Can be. More preferably, it is about 50 pieces / cm ² .

The corona electrode 11 may be formed like a corona electrode 11-3 illustrated in FIG.
The corona electrode 11-3 includes a flat plate 33 arranged so as to face the electromechanical conversion element 20, and a plurality of needle electrodes 34 arranged perpendicularly to the flat plate 33 at intervals, and the pointed protrusion 110. Have as. The flat plate 33 is preferably an electrode plate formed to the size of the corona electrode 11 and having a plate thickness of 1 mm or less, for example.
The needle electrode 34 is orthogonal to the upper surface of the electro-mechanical conversion element 20, the tip is disposed in a manner facing the electro-mechanical conversion element 20, and the tip position on the side facing the electro-mechanical conversion element 20 is aligned. .

For example, tungsten needle electrodes 34 of about φ2 mm are preferably inserted into needle holes (not shown) at a pitch of 3 mm on the surface of the flat plate 33 facing the electromechanical conversion element 20. The electrode density can be, for example, about 5 tungsten needles / cm ^{2 to} 20 / cm ² . More preferably, it is about 11 tungsten needles / cm ² .

  The flat plate 33 is preferably provided with a through hole 35 having a diameter of about φ0.8 mm, for example, between the needle electrodes 34, so that gas can flow from above. Although it does not specifically limit as gas, For example, the gas of 20% of oxygen / 80% of nitrogen is preferable. Also, dry air may be used. The durability of the corona electrode 11 can be improved by flowing a gas from the upper part of the flat plate 33 through the through hole 35 to stabilize the current.

  As described above, the corona electrode 11 is an electrode having a planar shape, and has a plurality of pointed protrusions 110 shown in FIGS. 4A to 4C on the facing surface facing the electromechanical conversion element 20. And stabilize corona discharge.

  Regarding the polarity of the corona electrode 11, it has been found that applying positive and negative voltages to the corona electrode 11 reverses the characteristics. For this reason, in driving the electromechanical conversion element 20, it is necessary to set the polarity so that the polarization effect can be obtained in the voltage range to be used. Therefore, the corona electrode 11 of this embodiment is preferably a positive electrode.

  The grid electrode 12 is disposed between the corona electrode 11 and the stage 13 and is preferably disposed parallel to the stage 13. The configuration of the grid electrode 12 is not particularly limited, but is preferably configured with a larger area than the electro-mechanical conversion element 20. In addition, when a high voltage is applied to the corona electrode 11 by applying mesh processing, ions and electric charges generated by corona discharge are efficiently and uniformly dispersed and poured onto the lower stage 13. It is preferable.

  A heating mechanism is added to the stage 13 so that the electro-mechanical conversion element 20 can be heated. The specific means of the heating mechanism for heating the electromechanical conversion element 20 is not particularly limited, and it can be configured to heat using various heaters, lamps, and the like. In addition, the heating mechanism can be installed in the stage 13 or can be installed so as to heat from the outside of the stage 13. In particular, in order to avoid interference with an electrode or the like, it is preferable to be installed in the stage 13.

  The maximum heating temperature of the heating mechanism is not particularly limited, as long as the heating mechanism can be heated to a predetermined temperature according to the Curie temperature of the electro-mechanical conversion film of the electro-mechanical conversion element 20 to be manufactured. . In particular, it is preferably configured to be able to heat up to a maximum of 350 ° C. so as to be compatible with various electro-mechanical conversion elements.

  In addition, it is preferable that the stage 13 on which the sample is placed is grounded so that electric charges can easily flow to the sample placed on the stage 13. That is, the ground wire 16 is preferably connected to the stage 13.

  The magnitude of the voltage applied to the corona electrode 11 and the grid electrode 12 and the distance between the sample and each electrode are not particularly limited, and these are adjusted so that the polarization treatment can be sufficiently performed. Can be strong or weak.

Further, the amount of charge Q required for performing the polarization treatment is not particularly limited, but it is preferable that a charge amount of 1.0 × 10 ⁻⁸ C or more is accumulated in the electromechanical conversion element. More preferably, a charge amount of 4.0 × 10 ⁻⁸ C or more is accumulated.

  It is preferable that the electromechanical conversion device manufacturing apparatus 10 further includes a turning mechanism 120 for turning the corona electrode 11 in the horizontal direction in parallel with the upper surface of the electromechanical conversion element 20. The illustrated turning mechanism 120 is provided at the center position on the upper surface side of the corona electrode 11 (the surface opposite to the electro-mechanical conversion element 20 side). The corona electrode 11 is, for example, at a speed of 10 rotations / minute to a speed of 100 rotations / minute so as to draw a circle in the horizontal direction at a position above the electro-mechanical conversion element 20 in the polarization process. More preferably, the vehicle is turned at a speed of 100 revolutions / minute. The configuration of the turning mechanism 120 is not limited to the illustrated example.

  As described above, the corona electrode 11 is swung by the swivel mechanism 120, so that the bias of charges supplied from the plurality of tip protrusions 110 can be reduced, and a high polarizability can be obtained.

[Second Embodiment]
A configuration example of the electro-mechanical transducer manufacturing apparatus according to the second embodiment will be described with reference to FIG.
The electro-mechanical conversion element manufacturing apparatus 10 of the present embodiment also includes an electro-mechanical conversion element 20 having a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are stacked on a substrate or a base film. On the other hand, it is an electro-mechanical transducer manufacturing apparatus 10 that performs polarization processing.

The second embodiment is based on substantially the same technical idea as the first embodiment, and only differences from the first embodiment will be described below.
The difference from the first embodiment is that the stage 13 of the electro-mechanical transducer manufacturing apparatus 10 is arranged in the horizontal direction (X-X direction, Y-Y direction) with the grid electrode 12 subjected to mesh processing. It is in a point that it is configured to be movable. The moving distance of the stage 13 is preferably greater than or equal to the mesh pitch P1, P2 of the grid electrode 12. The horizontal movement direction of the stage 13 can be appropriately changed depending on the mesh shape or the like, and can be moved in an oblique direction, for example.

  In this embodiment, a scorotron method is employed to ensure in-plane uniformity, and the stage 13 can be moved relative to the grid electrode 12. Therefore, during the polarization process, the stage 13 is horizontally moved to a mesh pitch P1, P2 or more of the grid electrode 12 to disperse the decrease in the charge amount in the shaded area of the grid electrode 12. In-plane uniformity is further improved.

[Third Embodiment]
A configuration example of the electro-mechanical transducer manufacturing apparatus according to the third embodiment will be described with reference to FIG.
The electro-mechanical conversion element manufacturing apparatus 10 of the present embodiment also includes an electro-mechanical conversion element 20 having a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are stacked on a substrate or a base film. On the other hand, it is an electro-mechanical transducer manufacturing apparatus 10 that performs polarization processing.

  The third embodiment is based on substantially the same technical idea as the first and second embodiments, and only differences from the first and second embodiments will be described below.

  The stage 13 of the present embodiment includes a stage main body 130 on which the electromechanical conversion element 20 is installed, a stage heating unit 131 having a heating mechanism (not shown), and the distance between the stage main body 130 and the stage heating unit 131. Displacement means 132 for displacing the.

  Specifically, while the stage main body 130 is heated by the heating mechanism and the polarization process is being performed, the stage heating unit 131 is gradually lowered by the displacing means 132 to gradually lower the temperature of the silicon wafer 17. It is supposed to be configured. Thereby, even when the temperature is lowered, depolarization due to heat can be prevented, and characteristics after the polarization treatment can be maintained.

  Further, the corona electrode 11 of the present embodiment is connected to a corona electrode power source 14 having a voltage adjustment mechanism 140. Accordingly, during the polarization process, when the temperature of the silicon wafer 17 is lowered by lowering the stage heating unit 131 by the displacement means 132 described above, the voltage applied to the corona electrode 11 by the voltage adjusting mechanism 140 can be gradually lowered. It becomes. Therefore, the occurrence of cracks can be reliably prevented by gradually reducing the polarization treatment conditions.

(Method for manufacturing electro-mechanical conversion element)
Next, the manufacturing method of the electromechanical conversion element of this embodiment is demonstrated.
In the method for manufacturing an electromechanical conversion element, the electromechanical conversion element 20 having a structure in which a first electrode, an electromechanical conversion film, and a second electrode are stacked on a substrate or a base film may be manufactured. it can.

  Specifically, the method for manufacturing the electro-mechanical conversion element of the present embodiment is performed using the above-described electro-mechanical conversion element manufacturing apparatus 10 (shown in FIGS. 2 to 6), that is, a polarization apparatus. it can.

First, before the polarization treatment is performed, each process of manufacturing the electromechanical conversion element having the first and second insulating protective films and the third and fourth electrodes is simplified with reference to FIG. Explained.
FIG. 11A shows a cross-sectional configuration diagram of the electro-mechanical conversion element, and FIG. 11B shows a plan view of the electro-mechanical conversion element. A cross-sectional view taken along line AA ′ in FIG. 11B corresponds to FIG. In FIG. 11B, the description of the first and second protective films (interlayer insulating films) is omitted for easy understanding of the configuration.

  A first electrode (lower electrode) 23 is laminated on the substrate 21 and the base film (vibrating plate) 22 by, for example, a sputtering apparatus. The first electrode has a structure in which, for example, an adhesion layer, a metal electrode film, and an oxide electrode film are stacked.

  Next, the electro-mechanical conversion film 24 is formed on the upper surface of the first electrode by repeatedly performing the steps of film formation, drying, and thermal decomposition, for example, by a spin coat method.

  Next, a second electrode (upper electrode) 25 is laminated on the upper surface of the electromechanical conversion film 24 by, for example, sputtering. Then, after forming a resist pattern by photolithography, a pattern shown in FIG. 11B is manufactured using an etching apparatus or the like.

  Therefore, as shown in FIG. 11B, the electromechanical conversion film 24 and the second electrode 25 can be in an individualized state. The first electrode functions as a common electrode, that is, a common electrode for the individual electro-mechanical conversion film 24 and the second electrode 25. Since the second electrodes 25 are individualized, they function as individual electrodes.

  Then, the first insulating protective film 26 is formed on the first electrode 23 and the individualized second electrode 25 by using, for example, an ALD method. A contact hole 27 exposing the first electrode 23 and the second electrode 25 is formed in the first insulating protective film 26. Then, the third electrode 28 and the fourth electrode 30 electrically connected to the first electrode 23 and the second electrode 25 through the contact hole 27 are formed by sputtering film formation and etching.

  A pad (common electrode pad) 29 is connected to the third electrode 28, and a pad (individual electrode pad) 31 is connected to the fourth electrode 30. Then, on the third electrode 28 and the fourth electrode 30, a second insulating protective film 32 having an opening exposing at least a part of the pads 29, 31 is formed by, for example, plasma CVD.

  Here, it is preferable that bumps are formed on the individual electrode pads 31 of the electromechanical conversion element 20 before the polarization treatment by corona charging or the like to increase the surface area of the individual electrode pads 31. Although illustration is omitted, it is preferable that the DrIC for driving the electromechanical conversion element is mounted on the piezoelectric element (electromechanical conversion element 20).

  The method for manufacturing the electro-mechanical conversion element according to the present embodiment includes a polarization processing step of performing polarization processing on the electro-mechanical conversion element 20 manufactured up to the above-described state. Next, the polarization process process of this embodiment is demonstrated.

  In the polarization processing step in the manufacturing method of the electromechanical conversion element of the present embodiment, the corona electrode 11 has an area of φ115 or more with respect to the 6-inch silicon wafer 17, for example. -Polarization treatment of the mechanical conversion element 20 can be performed at one time. In this embodiment, 25 pieces are arranged in an area of 30 mm × 10 mm square in a 6-inch silicon wafer.

  The corona electrode 11 to be used has a pointed protrusion 110 (needle electrode 30, saw blade electrode 32, needle electrode 34) of any one of FIGS. An appropriate corona electrode 11 is selected depending on the structure of the electromechanical conversion element 20 and the size of the silicon wafer 17.

  In the polarization process, the electro-mechanical conversion element 20 is heated below the Curie temperature of the electro-mechanical conversion film by the heating mechanism provided in the stage heating unit 131 of the stage 13 described above. Incidentally, when the electro-mechanical conversion film 24 is a PZT film, it is preferably heated at 160 ° C.

The charge amount Q required for performing the polarization treatment is preferably such that a charge amount of 1.0 × 10 ⁻⁸ C or more is accumulated in the electromechanical conversion element 20 and is 4.0 × 10 ⁻⁸ C or more. More preferred.

  In the polarization treatment step, it is preferable that the corona electrode 11 of the electro-mechanical conversion element manufacturing apparatus is a positive electrode, and the charge generated by the corona discharge is positively charged. As a result, the drive waveform on the positive side may be applied to the individual electrode of the electromechanical conversion element 20, and the drive circuit configuration can be simplified.

Next, the polarization treatment process performed by the electromechanical transducer manufacturing apparatus 10 according to the second and third embodiments will be described in the above polarization treatment process.
According to the electro-mechanical conversion element manufacturing apparatus 10 of the second embodiment, in the polarization processing step, the stage 13 and the grid electrode 12 on which the mesh processing is applied to the electro-mechanical conversion element 20 and the horizontal direction (X− X direction, YY direction) (see FIG. 5). The moving distance of the stage 13 is preferably equal to or greater than the mesh pitches P1 and P2 of the grid electrode 12. In the present embodiment, in order to ensure in-plane uniformity, a scorotron method is employed, and the stage 13 can be moved relative to the grid electrode 12.

  Therefore, by horizontally moving the stage 13 to the mesh pitch P1, P2 or more during corona discharge, it is possible to disperse the decrease in the charge amount in the shaded area of the grid electrode 12 and uniform in the plane. The property is further improved.

  According to the electro-mechanical conversion element manufacturing apparatus 10 of the third embodiment, the stage body 130 is heated by the stage heating unit 131 in the polarization process. Moreover, it has the displacement means 132 which gradually separates between the stage heating part 131 and the stage main-body part 130 (refer FIG. 6).

  The displacing unit 132 gradually separates the stage heating unit 131 and the stage main body unit 130 during the polarization process. Then, the temperature of the electromechanical conversion element 20 manufactured on the stage main body 130 can be gradually lowered. Therefore, the polarization process can be continued while lowering the silicon wafer 17 to a predetermined temperature (for example, 80 ° C.). As a result, depolarization that occurs when the temperature is suddenly lowered can be prevented, and the characteristics after the polarization treatment can be maintained.

  In addition, when the stage heating unit 131 is lowered by the displacement means 132 described above, it is preferable that the voltage applied to the corona electrode 11 by the voltage adjustment mechanism 140 is also lowered. In this way, by gradually reducing the polarization treatment conditions, it is possible to reliably prevent the occurrence of cracks and the like.

  The electro-mechanical conversion element manufacturing method using the electro-mechanical conversion element manufacturing apparatus according to the first to third embodiments has been described above. The electro-mechanical apparatus according to the first to third embodiments has been described. It is preferable to manufacture the electro-mechanical conversion element 20 in combination with a conversion element manufacturing apparatus.

  According to the manufacturing method according to the present embodiment, it is possible to manufacture an electro-mechanical conversion element that is sufficiently polarized without damaging the electro-mechanical conversion film, the substrate, or the base film.

(Principle of polarization processing)
Next, an example of the principle of polarization processing by the electro-mechanical transducer manufacturing apparatus 10 will be described with reference to FIG. The electro-mechanical conversion element manufacturing apparatus 10 performs polarization processing on the piezoelectric element by corona discharge and a stage voltage.

  When a voltage is applied to the corona electrode, molecules in the atmosphere are ionized by corona discharge to generate cations and anions. These ions are applied to the stage through a grid electrode (not shown) to which mesh processing is applied and a grid voltage is applied.

  A positive ion is injected into the electro-mechanical conversion element through the common electrode pad and the individual electrode pad (not shown) of the electro-mechanical conversion element (piezoelectric element), so that the charge of the opposite polarity is electro-mechanical. Accumulate in the upper and lower electrodes of the conversion element. In addition, when a voltage is applied to the electro-mechanical conversion element through the through hole, a larger internal voltage difference is generated between the upper electrode and the lower electrode of the electro-mechanical conversion element, and the piezoelectric element is polarized.

  Further, as shown in FIG. 8A, when the number of individual electrodes is A and the number of common electrodes is B (here, the area of the individual electrodes and the common electrodes is assumed to be the same), the charge amount Q is generated. FIG. 8B shows how much electric charge is accumulated in one electro-mechanical conversion element. The common electrode has a predetermined resistance value with respect to the back surface of the silicon substrate. In this embodiment, the common electrode has a resistance of about 1E7Ω, and the charge at the time of the polarization process almost flows to GND, and the charge applied to the individual electrode. Thus, it is considered that a potential difference is generated and polarization processing is performed.

  The state of the polarization treatment can be determined from the PE hysteresis loop of the electromechanical conversion element. A method for determining the state of polarization processing will be described with reference to FIG.

Examples of the PE hysteresis loop are shown in FIGS. FIG. 9A shows a sample before the polarization process, and FIG. 9B shows a PE hysteresis loop after the polarization process.
As shown in FIG. 9, when measuring a hysteresis loop with an electric field strength of ± 150 kV / cm, the polarization at 0 kV / cm before applying a voltage is Pini, and up to 0 kV / cm after applying a voltage of +150 kV / cm The returned polarization at 0 kV / cm is Pr.

At this time, the value of Pr-Pini is defined as the polarizability, and it is possible to determine whether or not the polarization state is appropriate based on the polarizability. Specifically, as shown in FIG. 9 (B), it is preferable that the value of the polarizability Pr-Pini is not more than a predetermined value for the sample after the polarization treatment. For example, it is preferable that has a 10 [mu] C / cm ² or less, further preferably has a 5 [mu] C / cm ² or less. When the value of Pr-Pini is not sufficiently small, the polarization is not sufficiently performed, and the displacement amount of the electromechanical conversion element with respect to the predetermined drive voltage is not stable.

  Here, a case where a polarization treatment is performed at room temperature on an electro-mechanical conversion element using platinum electrodes as the first and second electrodes and PZT as the electro-mechanical conversion film on the Si substrate, and heating at 80 ° C. FIG. 10 shows the relationship between the occurrence rate of cracks generated in the film and the polarizability when the polarization treatment is performed. The crack occurrence rate is the number of bits where cracks have occurred / total bits. The corona electrode used is a single tungsten wire.

  When the polarization treatment is performed at room temperature, it is understood that the crack generation rate increases when the polarization rate is decreased, and the relationship between these two is a trade-off. Here, the number of bits means the number of individual electro-mechanical conversion films in the measurement range.

  According to this, when the polarization treatment is performed by heating to 80 ° C., the crack generation rate tends to increase as the polarizability decreases, but it is better to perform the polarization treatment while heating compared to the polarization treatment at room temperature. It can be seen that the polarizability obtained without cracks is small. This is because when the polarization treatment is performed while heating, the stress can be relaxed in the electro-mechanical conversion film, so that the desired polarizability can be obtained. Inferred.

  In the corona electrode processing using a single tungsten wire, the substrates are sequentially fed when the piezoelectric elements arranged on the silicon wafer are sequentially polarized. Therefore, if the substrate temperature is further increased to 120 ° C. and 160 ° C., the piezoelectric elements placed on the silicon wafer are subjected to polarization processing in order, and after the polarization processing is performed, the piezoelectric elements are removed while being held at the substrate heating temperature. Polarization occurs and the difference in polarization amount increases. Therefore, the substrate could not be heated to 80 ° C. or higher.

  On the other hand, a structure in which a plurality of tungsten wires are arranged to form a corona electrode, heated to 80 ° C. or more in units of silicon wafers, and subjected to polarization treatment in a silicon wafer surface is also being studied. However, there has been a problem that the variation in the amount of polarization difference in the silicon wafer surface increases depending on the wire arrangement.

  In the present embodiment, as described above, a plurality of electro-mechanical conversion elements 20 manufactured on the silicon wafer 17 are obtained by performing corona discharge with the corona electrode 11 having a planar shape having substantially the same size as the silicon wafer 17. Can be corona-polarized at once. This eliminates the need to hold the electromechanical conversion element 20 in a heated state after the polarization treatment, and the polarization treatment can be performed by heating the substrate temperature to 80 ° C. or higher. Therefore, variation in polarization treatment can be reduced, and the substrate heating effect can be further reduced as a difference in polarization amount obtained without cracks. In addition, the time required for manufacturing the piezoelectric element can be greatly reduced.

[Fourth Embodiment]
In the present embodiment, a configuration example of the electromechanical conversion element 20 of the present invention will be described with reference to FIG. The electro-mechanical conversion element 20 of this embodiment has a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are stacked on a substrate or a base film.

When the hysteresis loop was measured with an electric field strength of ± 150 kV / cm applied to the electromechanical conversion film, the polarization at 0 kV / cm before applying the voltage was Pini, and 0 kV / cm after applying the voltage of +150 kV / cm. Let Pr be the polarization at 0 kV / cm when the pressure is returned to the maximum. In this case, the polarizability Pr-Pini is preferably 10 μC / cm ² or less. In particular, the polarizability Pr-Pini is preferably 5 μC / cm ² or less.

  Such an electro-mechanical conversion element is sufficiently polarized and can stabilize the amount of displacement of the electro-mechanical conversion element with respect to a predetermined drive voltage. For this reason, sufficient characteristics can be stably obtained even in the initial stage or after continuous driving.

  In the electro-mechanical conversion element of this embodiment, the electro-mechanical conversion film and the second electrode are preferably individualized.

  In this case, the first electrode and the second electrode are further connected to each other through the first insulating protective film formed on the first electrode and the second electrode, and the contact hole formed in the first insulating protective film. It can be set as the structure which has a 3rd electrode and a 4th electrode electrically connected with an electrode.

  In addition, as shown in FIG. 11, the third electrode and the fourth electrode are connected to the pad, and the second insulating protective film is provided on the third electrode and the fourth electrode. The insulating protective film may have a configuration in which an opening exposing at least a part of the pad is formed.

Below, each member of the electromechanical conversion element 20 of this embodiment is demonstrated using FIG.
As described below, the electromechanical conversion element of this embodiment can be formed on the substrate 21 or the base film (vibration plate) 22.

  The material of the substrate 21 is not particularly limited, but it is preferable to use a silicon single crystal substrate in view of ease of processing, availability, and the like.

  The silicon single crystal substrate has three types of plane orientations (100), (110), and (111), but is not particularly limited, and an appropriate substrate can be selected according to the content of processing. it can.

  For example, when etching processing is required for a substrate, a substrate having a predetermined plane orientation can be selected in accordance with the content of the etching processing. In the case of forming a droplet discharge head, which will be described later, as an example, a pressure chamber is usually formed on a substrate by etching, and anisotropic etching is generally used as an etching method at this time. Here, the anisotropic etching utilizes the property that the etching rate is different with respect to the plane orientation of the crystal structure. For example, in anisotropic etching immersed in an alkaline solution such as KOH, the (100) plane is used. In contrast, the (111) plane has an etching rate of about 1/400. Accordingly, while a structure having an inclination of about 54 ° can be produced in the plane orientation (100), deep grooves can be dug in the plane orientation (110), and the arrangement density is increased while maintaining rigidity. I know I can. For this reason, for example, in the case of a substrate constituting a droplet discharge head, a silicon single crystal substrate having a (110) plane orientation can be preferably used.

  Although the thickness of the board | substrate 21 can be selected by a use etc. and is not specifically limited, For example, what has a thickness of 100-600 micrometers can be used preferably.

  The base film (vibrating plate) 22 can be provided, for example, when a droplet discharge head is formed as will be described later. In some applications, an electro-mechanical conversion element is provided on the substrate 21 without providing the base film 22. You can also.

For example, in the case of a droplet discharge head, the base film 22 receives a force generated by the electro-mechanical conversion film and is deformed and displaced to discharge a liquid (for example, ink) in the pressurizing chamber. Therefore, it is preferable that the base film 22 has a predetermined strength. Examples of the material include Si, SiO ₂ , and Si ₃ N ₄ produced by the CVD method. In particular, it is preferable to select a material close to the linear expansion coefficient of the first electrode and the electromechanical conversion film. When PZT is used as the electro-mechanical conversion film, it has a linear expansion coefficient of 5 × 10 ⁻⁶ to 10 × 10 ⁻⁶ (1 / K), which is close to its linear expansion coefficient of 8 × 10 ⁻⁶ (1 / K). The material having a linear expansion coefficient of 7 × 10 ^{−6 to} 9 × 10 ⁻⁶ (1 / K) is more preferable.

  Specifically, for example, aluminum oxide, zirconium oxide, iridium oxide, ruthenium oxide, tantalum oxide, hafnium oxide, osmium oxide, rhenium oxide, rhodium oxide, palladium oxide, and compounds thereof can be preferably used.

  Although the formation method of the base film 22 is not particularly limited, it can be formed by a spin coater using a sputtering method or a Sol-gel method.

  Although it does not specifically limit as a film thickness of a base film, It is preferable that they are 0.1 micrometer or more and 10 micrometers or less, and it is more preferable that they are 0.5 micrometer or more and 3 micrometers or less. If it is smaller than this range, for example, in the case of a droplet discharge head described later, it becomes difficult to process the pressurizing chamber, and if it is larger than this range, the underlying film is difficult to be deformed and displaced, and droplet discharge may become unstable. It is not preferable.

  The first electrode 23 is not particularly limited and can be arbitrarily selected. For example, it can be composed of a metal electrode film or an oxide electrode film, and is particularly preferably a laminate of a metal electrode film and an oxide electrode film.

  Examples of the metal electrode film include platinum group elements such as platinum, iridium, and rhodium, and films made of these alloys such as platinum-rhodium.

In the case where platinum is used as the metal electrode film, the adhesion between the substrate and the metal electrode film is poor because the adhesion to the substrate (especially when SiO ₂ is formed on the substrate surface) is poor. It is preferable to form an adhesion layer to be described later.

  The method for producing the metal electrode film is not particularly limited, and various film forming methods can be employed. For example, vacuum film formation such as sputtering or vacuum deposition is common. The film thickness is not particularly limited, but is preferably 80 nm to 200 nm, and preferably 100 nm to 150 nm. This is because sufficient current may not be supplied when the metal electrode film is too thin. If the film thickness is too thick, the metal electrode film is composed of an expensive white metal material, which increases the cost. If the film thickness is increased, the surface roughness increases. This is because the surface roughness and crystal orientation of the layer laminated thereon may be affected.

The material of the oxide electrode film is not particularly limited, but for example, SrRuO ₃ can be preferably used. In addition to SrRuO ₃ , Sr _x A _(1-x) Ru _y O _(1-y) (A: Ba, Ca B: Co, Ni x, y = 0 to 0.5) Can also be preferably used.

  A method for forming the oxide electrode film is not particularly limited, but the oxide electrode film can be formed by a sputtering method.

As the electro-mechanical conversion film described later, PZT is preferably used, and PZT is preferably (111) oriented. Therefore, when SrRuO ₃ is used as the oxide electrode film, SrRuO ₃ is also (111) oriented. Preferably it is. However, it is known that the film quality of SrRuO ₃ changes depending on the sputtering conditions. For example, when (111) -oriented Pt is used as the metal electrode film and the Pt film is formed, the SrRuO ₃ film is formed. In this case, it is preferable to form a film by heating the substrate to 500 ° C. or higher.

Note that the crystallinity of the SrRuO ₃ film formed on Pt (111) is close to the lattice constant between Pt and SrRuO ₃ film, and therefore, in the normal θ-2θ measurement, the SrRuO ₃ film (111) and Pt (111) These 2θ positions overlap and are difficult to discriminate. With respect to Pt, diffraction lines cancel each other at a position where 2θ tilted by Psi = 35 ° is about 32 ° due to the disappearance rule, and no diffraction intensity is observed. Therefore, it was possible to confirm whether the SrRuO ₃ film is preferentially oriented to (111) by inclining the Psi direction by about 35 ° and judging from the peak intensity where 2θ is about 32 °. In addition, regarding the SrRuO ₃ film produced by the room temperature film formation + RTA process described above, the diffraction intensity of SRO (110) is observed when Psi = 0 °.

The surface roughness of the SrRuO ₃ film is not particularly limited, but is preferably 4 nm or more and 15 nm, and more preferably 6 nm or more and 10 nm or less. This is because if the surface roughness is larger than the above range, the withstand voltage of the electro-mechanical conversion film formed thereafter may deteriorate and a leakage current may be generated.

Further, although it is preferable that the surface roughness is small, the surface roughness is affected by the film formation temperature, and when the film is formed from room temperature to 300 ° C., the surface roughness can be extremely reduced, for example, 2 nm or less. It can also be. However, this is not preferable because the crystallinity of the SrRuO ₃ film is lowered. For this reason, it is preferable that surface roughness Ra is the said range. In addition, the surface roughness here means surface roughness Ra (center line average roughness) measured by AFM. In order to obtain the SrRuO ₃ film having the above surface roughness and high crystallinity, the film forming temperature is preferably 500 ° C. to 700 ° C., more preferably 520 ° C. to 600 ° C. .

When SrRuO ₃ is used as the oxide electrode film, the Sr / Ru (ratio of substance amount) is 0.82 or more and 1.22 or less with respect to the composition ratio of Sr and Ru after the formation of the SrRuO ₃ film. It is preferable. This is because if it is out of this range, the specific resistance increases, and sufficient conductivity as an electrode may not be obtained.

  The thickness of the oxide electrode film is not particularly limited, but is preferably 40 nm or more and 150 nm or less, and more preferably 50 nm or more and 80 nm or less. If the thickness is less than this range, sufficient characteristics cannot be obtained for initial displacement and displacement deterioration after continuous driving, or as a stop etching layer for suppressing over-etching when etching an electro-mechanical conversion film. It becomes difficult to obtain functions. On the other hand, if it exceeds this range, the withstand voltage of the electro-mechanical conversion film formed thereafter is deteriorated, which may cause a leakage current, which is not preferable.

In addition, the specific resistance of the oxide electrode film is preferably 5 × 10 ⁻³ Ω · cm or less and more preferably 1 × 10 ⁻³ Ω · cm or less in order to have sufficient conductivity as an electrode. More preferably.

Further, as described above, an adhesion layer can be provided between the substrate 21 and the first electrode 23 or between the base film 22 and the first electrode 23. A TiO ₂ film can be preferably used as the adhesion layer. In addition, oxides such as Ta, Ir, and Ru can be preferably used.

The method for forming the TiO ₂ film is not particularly limited. For example, the film can be formed by reactive sputtering, but a titanium film thermally oxidized at a high temperature can be preferably used. Specifically, it is preferable to use a material obtained by thermal oxidation in an oxygen atmosphere at 650 to 800 ° C. for 1 to 30 minutes using an RTA (rapid thermal annealing) apparatus after sputtering sputtering of Ti. .

  This is because the production by reactive sputtering requires a special sputtering chamber configuration because the silicon substrate needs to be heated at a high temperature. Furthermore, according to oxidation in a normal heating furnace, an easily oxidizable titanium film forms several crystal structures at low temperatures, so it is necessary to break it once. This is because good crystals can be formed. An oxide film can be formed in the same manner for other metals.

  The thickness of the adhesion layer is preferably 10 nm to 50 nm, and more preferably 15 nm to 30 nm. If it is thinner than this, it may not have the effect of sufficiently improving the adhesion, and if it is thicker than this range, it may affect the quality of the crystal such as the electrode film laminated on it. .

  The electro-mechanical conversion film 24 may be any material that exhibits piezoelectric characteristics, and is not particularly limited, but is preferably formed from an oxide containing Pb.

In particular, as an electro-mechanical conversion film, PZT can be preferably used because of its high piezoelectric characteristics. PZT is a solid solution of lead zirconate (PbTiO ₃ ) and titanic acid (PbTiO ₃ ), and the characteristics differ depending on the ratio. In general, the composition exhibiting excellent piezoelectric characteristics has a ratio of PbZrO ₃ and PbTiO ₃ of 53:47. In terms of chemical formula, Pb (Zr _0.53 , Ti _0.47 ) O ₃ , generally PZT Also shown as (53/47).

  Examples of composite oxides other than PZT include barium titanate and materials having the same structure. In this case, barium alkoxide precursor solution is prepared by dissolving barium alkoxide and titanium alkoxide compound in a common solvent. It is also possible to produce.

These materials are described by the general formula ABO ₃ where A is one or more elements selected from Pb, Ba, Sr and B is selected from Ti, Zr, Sn, Ni, Zn, Mg, Nb. It can be one or more elements. Then, a composite oxide composed mainly of ABO ₃ according electrically - can be preferably used as the transducer layer. The A, element B is in the specific _{(Pb 1-x, Ba)} (Zr, Ti) O 3, may be described as (Pb 1-x, Sr) (Zr, Ti) O 3, etc. it can. This is the case where Pb at the A site is partially replaced with Ba or Sr. 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.

  The relative dielectric constant of the electromechanical conversion film is preferably 600 or more and 2000 or less, and more preferably 1200 or more and 1600 or less. By setting the relative dielectric constant within the above range, sufficient displacement characteristics can be obtained. Further, the polarization process can be sufficiently performed, and sufficient characteristics can be obtained with respect to the displacement deterioration after continuous driving.

  The method for producing the electro-mechanical conversion film is not particularly limited, but for example, it can be produced by a spin coater using a sputtering method or a Sol-gel method. In any case, since patterning is required, a desired pattern is obtained by photolithography etching or the like.

  The production procedure will be described taking as an example the case of producing PZT by the Sol-gel method. First, lead acetate, zirconium alkoxide, and titanium alkoxide compounds are used as starting materials, and these starting materials are dissolved in methoxyethanol as a common solvent to obtain a uniform solution, whereby a PZT precursor solution can be prepared. Since the metal alkoxide compound is easily hydrolyzed by moisture in the atmosphere, an appropriate amount of a stabilizer such as acetylacetone, acetic acid or diethanolamine may be added as a stabilizer to the precursor solution.

  When a PZT film is obtained on the entire surface of the base substrate on which the first electrode and the like are formed, it is obtained by forming a coating film by a solution coating method such as spin coating, and performing heat treatments such as solvent drying, thermal decomposition, and crystallization. It is done. Since the transformation from the coating film to the crystallized film involves volume shrinkage, it is preferable to adjust the concentration of the precursor solution so that a film thickness of 100 nm or less can be obtained in one step in order to obtain a crack-free film. .

  The thickness of the electro-mechanical conversion film is not particularly limited, and can be arbitrarily selected depending on the required displacement amount. For example, the film thickness is preferably 0.5 μm or more and 5 μm or less, and more preferably 1 μm or more and 2 μm or less. Sufficient displacement can be generated by setting the film thickness within such a range. In addition, if the film thickness is in such a range, the number of steps to be stacked and formed does not increase more than necessary, so that it can be manufactured with high productivity.

  The second electrode 25 is not particularly limited and can be arbitrarily selected. For example, it can be composed of a metal electrode film or an oxide electrode film, and is particularly preferably a laminate of a metal electrode film and an oxide electrode film.

  The metal electrode film is not particularly limited, and for example, the same material as that for the first electrode can be preferably used.

  The film thickness is preferably 30 nm to 200 nm, more preferably 50 nm to 120 nm. If the film thickness is made thinner than the above range, there may be a case where a sufficient current cannot be supplied as an electrode. If the film thickness is larger than the above range, the cost increases when an expensive platinum group element material is used as the electrode material. In particular, when platinum is used as the material, the surface roughness increases as the film thickness increases, and film peeling may occur when another material is laminated on the metal electrode film. It is not preferable.

  The material of the oxide electrode film is not particularly limited, but for example, the same material as that of the first electrode can be preferably used.

  The thickness of the oxide electrode film is not particularly limited, but is preferably 20 nm to 80 nm, and more preferably 40 nm to 60 nm. If it is thinner than this film thickness range, sufficient initial displacement and displacement deterioration characteristics may not be obtained. On the other hand, if it exceeds this range, the dielectric strength voltage of the PZT formed thereafter is very bad, and it may become easy to leak, which is not preferable.

  As described above, the first insulating protective film 26 can be provided in the electromechanical conversion element of this embodiment. As the first insulating protective film, it is preferable to use a material that prevents damage to the electromechanical conversion element due to the film formation / etching process and is difficult to transmit moisture in the atmosphere. For this reason, a film of an inorganic material is preferable, and a dense film is particularly preferable.

In order to obtain high protection performance with a thin film, it is preferable to use an oxide, nitride, or carbonized film. In particular, the material is in contact with the first insulating protective film, that is, the base, the material of the second electrode 25 and the first electrode 23, the material of the electro-mechanical conversion film 24, and the material of the upper surface of the substrate 21. A high material is preferable. _{Therefore, Al 2 O 3, ZrO 2} , Y 2 O 3, Ta 2 O 3, an oxide film such as TiO ₂ can be cited as examples.

  The method for forming the first insulating protective film is not particularly limited, but it is preferable to select a film forming method that does not damage the electromechanical conversion element. For this reason, the vapor deposition method and the ALD method can be preferably used, and it is preferable to form the film by the ALD method having many choices of applicable materials. In particular, according to the ALD method, a thin film having a very high film density can be produced, and damage to the electromechanical conversion element during the process can be suppressed.

  The film thickness of the first insulating protective film is not particularly limited, but is sufficient to ensure the protection performance of the electromechanical conversion element and does not hinder the displacement of the electromechanical conversion element. Is preferably as thin as possible. For example, the thickness of the first insulating protective film is preferably in the range of 20 nm to 100 nm. If it is thicker than 100 nm, displacement of the electromechanical conversion element may be hindered. On the other hand, when the thickness is smaller than 20 nm, the function as a protective layer of the electro-mechanical conversion element is not sufficient, and the performance of the electro-mechanical conversion element may be deteriorated.

In addition, the first insulating protective film can be composed of a plurality of layers. For example, in the case of two layers, since the second insulating protective film is thickened, an opening is formed in the second insulating protective film in the vicinity of the second electrode so as not to significantly disturb the vibration displacement of the electromechanical conversion element. The structure which forms is also mentioned. In this case, as the second insulating protective film, any oxide, nitride, carbide, or a composite compound thereof can be used. For example, it is preferable to use SiO ₂ generally used in semiconductor devices. Arbitrary techniques can be used for film formation, and film formation can be performed by a CVD method, a sputtering method, or the like. In particular, it is preferable to use a CVD method capable of forming an isotropic film in consideration of the step coverage of the pattern forming portion such as the electrode forming portion.

  The film thickness of the second insulating protective film is not particularly limited, and it is preferable to select a film thickness that does not cause dielectric breakdown in consideration of the voltage applied to each electrode. That is, it is preferable to set the electric field strength applied to the insulating protective film within a range not causing dielectric breakdown. Furthermore, considering the surface properties of the base of the insulating protective film, pinholes, etc., the film thickness is preferably 200 nm or more, and more preferably 500 nm or more.

  As described above, each of the first electrode and the second electrode can be configured to be connected to the pad. In this case, the first electrode 23 and the second electrode 25 and the pads 29 and 31 can be connected by the third electrode 28 and the fourth electrode 30. In this case, the materials of the third electrode 28 and the fourth electrode 30 that connect each electrode and the pad are not particularly limited, and various conductive materials can be used. In particular, it is preferably made of any material selected from Cu, Al, Au, Pt, Ir, Ag alloy, and Al alloy.

  The method for manufacturing the third electrode 28 and the fourth electrode 30 is not particularly limited, and can be formed by any method. For example, a desired pattern can be obtained by using a sputtering method or a spin coating method and then photolithography etching or the like.

  The thickness of the connecting member is not particularly limited, but is preferably 0.1 μm or more and 20 μm or less, and more preferably 0.2 μm or more and 10 μm or less. If the film thickness is smaller than the range, the resistance increases, and a sufficient current may not flow through the electrode. On the other hand, when the thickness is larger than the above range, the production process takes time, which is not preferable because productivity is lowered.

  When the first insulating protective film 26 is provided, the third and fourth electrodes are each provided with a contact hole 27 in the first insulating protective film 26, and the first electrode 23 and the second electrode are provided in the contact hole. The electrode 25 can be connected. The size of the contact hole 27 is not particularly limited, but can be, for example, 10 μm × 10 μm. The contact resistance in the contact hole 27 is preferably 10Ω or less for the first electrode (common electrode) and 1Ω or less for the second electrode (individual electrode). This range is preferable because a sufficient current can be stably supplied to each electrode. In particular, the first electrode (common electrode) is preferably configured to be 5Ω or less, and the second electrode (individual electrode) is configured to be 0.5Ω or less.

  Moreover, the second insulating protective film 32 can be provided in the electromechanical conversion film of the present embodiment. The second insulating protective film 32 is a passivation layer having a function of protecting the third electrode 28 and the fourth electrode 30.

  As shown in FIG. 11, the second insulating protective film 32 covers the third electrode 28 and the fourth electrode 30, and pads 29 and 31 connected to the third electrode 28 and the fourth electrode 30. It can be set as the structure which has an opening part in a part. Thereby, even when inexpensive Al or an alloy material containing Al as a main component is used for the third electrode 28 and the fourth electrode 30, the reliability of the electromechanical conversion element can be improved. Moreover, since an inexpensive material can be used for these connection members and the like, the cost of the electromechanical conversion element can be reduced.

  The material of the second insulating protective film 32 is not particularly limited, and any inorganic material or organic material can be used. However, a material with particularly low moisture permeability is preferable. As the inorganic material, for example, oxide, nitride, carbide, or the like can be used. Moreover, as an organic material, a polyimide, an acrylic resin, a urethane resin etc. can be used, for example.

However, in the case of an organic material, in order to function as an insulating protective film, the film thickness becomes thick and it may be difficult to perform patterning. For this reason, the inorganic material which can exhibit a wiring protection function with a thin film can be used preferably. In particular, when Al wiring is used as the third electrode 28 and the fourth electrode 30, it is a technique that has a proven record in semiconductor devices that Si ₃ N ₄ is used as the second insulating protective film 32. Therefore, it is preferable.

  The film thickness of the second insulating protective film 32 is preferably 200 nm or more, and more preferably 500 nm or more. This is because, when the film thickness is small, a sufficient passivation function cannot be exhibited, and thus the reliability may be lowered due to the occurrence of disconnection due to corrosion of the third and fourth electrodes.

  In addition, the second insulating protective film preferably has a structure having an opening on the electromechanical conversion element, and in the case of a liquid droplet ejection head described later, the diaphragm also has a structure having an opening. It is preferable. This is in order not to significantly impede the vibration displacement of the electro-mechanical conversion element, which is preferable because it can be a highly efficient and reliable electro-mechanical conversion element.

  The second insulating protective film can form an opening for exposing each pad, and for example, a photolithography method and dry etching can be used to form the opening.

In addition, the area of the common electrode pad part and the individual electrode pad part is not particularly limited. However, when the polarization process is performed after the pad part and the second insulating protective film are formed, charges are supplied from the pad part. Therefore, it is preferable to select the area so that the polarization treatment can be sufficiently performed. For example, the size of each pad is preferably 50 × 50 μm ² or more, and more preferably 100 × 300 μm ² or more.

  As described above, the electro-mechanical conversion element 20 of the present embodiment has been described. However, the electro-mechanical conversion element 20 has no crack and is an electro-mechanical conversion element having a low polarizability. For this reason, the displacement amount with respect to the predetermined drive voltage of the electromechanical conversion element can be stabilized, and sufficient characteristics can be obtained stably even after the initial stage or after continuous drive.

  The method for manufacturing the electro-mechanical conversion element of the present embodiment is not particularly limited, but is preferably manufactured by the electro-mechanical conversion element manufacturing apparatus described in the first to third embodiments. Can do.

[Fifth Embodiment]
In this embodiment, a droplet discharge head including the electro-mechanical conversion element described in the fourth embodiment will be described.
The droplet discharge head according to the present embodiment includes a nozzle that discharges a droplet, a pressurizing chamber that communicates with the nozzle, and a discharge driving unit that pressurizes the liquid in the pressurizing chamber.

  The discharge driving means is the electro-mechanical conversion element 20 manufactured by the electro-mechanical conversion element manufacturing apparatus according to the first to third embodiments.

  A specific configuration will be described with reference to FIGS. FIG. 12 shows a droplet discharge head configuration having one nozzle. FIG. 13 shows the arrangement of a plurality of these.

  As shown in FIG. 13, in the droplet discharge head of this embodiment, a pressurizing chamber 81 is formed in the substrate 21 portion, and a nozzle 82 for discharging droplets is provided in the lower end portion of the pressurizing chamber 81. A nozzle plate 83 is arranged. Then, when a voltage is applied to the electro-mechanical conversion element and the electro-mechanical conversion film 24 is displaced, the base film (vibrating plate) 22 is deformed and displaced, and the liquid in the pressurizing chamber 81 is discharged from the nozzle 82. Has been. And as shown in FIG. 13, it can also be set as the structure which arranged the several droplet discharge head. In the figure, descriptions of liquid supply means, flow paths, and fluid resistance are omitted.

  Since the liquid droplet ejection head as described above includes the electro-mechanical conversion element described in the fourth embodiment, the electro-mechanical conversion element is sufficiently polarized in advance and has a low polarizability. It has become. For this reason, the electro-mechanical conversion element is stably deformed with respect to a predetermined potential, and as a result, the droplet discharge head can also perform stable droplet discharge.

[Sixth Embodiment]
In this embodiment, a droplet discharge apparatus including the droplet discharge head described in the fifth embodiment will be described.
A configuration example of the droplet discharge device of this embodiment will be described with reference to FIGS. FIG. 14 is a perspective explanatory view of the droplet discharge device, and FIG. 15 is a side view of a mechanism portion of the droplet discharge device.

  The droplet discharge device includes a carriage that can move in the main scanning direction inside the recording apparatus main body 91, a recording head that includes the droplet discharge head according to the fifth embodiment mounted on the carriage, and ink that supplies ink to the recording head. A printing mechanism 92 including a cartridge or the like is accommodated.

  A sheet feeding cassette (or a sheet feeding tray) 94 on which a large number of sheets 93 can be stacked from the front side can be removably mounted on the lower part of the apparatus main body 91, and the sheets 93 can be manually inserted. The manual feed tray 95 for feeding paper can be turned over. Then, the paper 93 fed from the paper feed cassette 94 or the manual feed tray 95 is taken in, and after a required image is recorded by the printing mechanism unit 92, the paper is discharged onto a paper discharge tray 96 mounted on the rear side.

  The printing mechanism 92 holds the carriage 103 slidably in the main scanning direction with a main guide rod 101 and a sub guide rod 102 which are guide members horizontally mounted on left and right side plates (not shown). The carriage 103 has a plurality of ink discharge ports (nozzles) as a head 104 including a droplet discharge head for discharging ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). They are arranged in a direction crossing the scanning direction. The ink droplet is ejected in the downward direction. Each ink cartridge 105 for supplying ink of each color to the head 104 is replaceably mounted on the carriage 103.

  The ink cartridge 105 has an atmosphere port communicating with the atmosphere above, a supply port for supplying ink to the inkjet head below, and a porous body filled with ink inside.

  The ink supplied to the inkjet head is maintained at a slight negative pressure by the capillary force of the porous body. Further, although the heads 104 of the respective colors are used here as the recording heads, a single head having nozzles that eject ink droplets of the respective colors may be used.

  Here, the carriage 103 is slidably fitted to the main guide rod 101 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the secondary guide rod 102 on the front side (upstream side in the paper conveyance direction). doing. In order to move and scan the carriage 103 in the main scanning direction, a timing belt 110 is stretched between a driving pulley 108 and a driven pulley 109 that are rotationally driven by a main scanning motor 107. The timing belt 110 is fixed to the carriage 103, and the carriage 103 is reciprocated by forward and reverse rotation of the main scanning motor 107.

  Next, a mechanism for conveying the sheet 93 set in the sheet feeding cassette 94 to the lower side of the head 104 will be described. First, a sheet feeding roller 111 and a friction pad 112 for separating and feeding the sheet 93 from the sheet feeding cassette 94, a guide member 113 for guiding the sheet 93, and a conveying roller 114 for inverting and feeding the fed sheet 93 are provided. Have. A conveyance roller 115 pressed against the peripheral surface of the conveyance roller 114 and a leading end roller 116 for defining a feeding angle of the sheet 93 from the conveyance roller 114 are provided. The conveyance roller 114 is driven to rotate by a sub-scanning motor 117 through a gear train.

  A printing receiving member 119 is provided as a paper guide member for guiding the paper sheet 93 fed from the transport roller 114 below the recording head 104 in accordance with the movement range of the carriage 103 in the main scanning direction. On the downstream side of the printing receiving member 119 in the paper conveyance direction, a conveyance roller 121 and a spur 122 that are rotationally driven to send the paper 93 in the paper discharge direction are provided. Further, a discharge roller 123 and a spur 124 for feeding the sheet 93 to the discharge tray 96, and guide members 125 and 126 for forming a discharge path are provided.

  At the time of recording, the recording head 104 is driven according to the image signal while moving the carriage 103, thereby ejecting ink onto the stopped sheet 93 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 93 has reached the recording area, the recording operation is terminated and the sheet 93 is discharged.

  Further, a recovery device 127 for recovering the ejection failure of the head 104 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 103. The recovery device 127 includes a cap unit, a suction unit, and a cleaning unit. While waiting for printing, the carriage 103 is moved to the recovery device 127 side and the head 104 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 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 an ejection failure occurs, the ejection port (nozzle) of the head 104 is sealed by the capping unit, and bubbles and the like are sucked out from the ejection port by the suction unit through the tube. As a result, the ink, dust, etc. adhering to the ejection port surface are 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.

  Since the droplet discharge device of this embodiment includes the droplet discharge head described in the fifth embodiment, the electro-mechanical conversion element included in the droplet discharge head is sufficiently subjected to polarization processing in advance. Therefore, the electro-mechanical conversion element has a low polarizability. For this reason, the electro-mechanical conversion element exhibits stable deformation with respect to a predetermined potential, and as a result, the droplet discharge device can also stably discharge droplets.

  Specific examples will be described below, but the present invention is not limited to these examples.

  First, evaluation methods in the following examples and comparative examples will be described.

  In this example, three different types of corona electrodes 11-1 to 11-3 shown in FIGS. 4A to 4C were manufactured. Samples 1 to 3 were used as the corona electrodes. Even if the shape of the corona electrode was changed, it was evaluated whether an appropriate polarization treatment was applied to the piezoelectric element. Using the electromechanical conversion element manufacturing apparatus 10 (FIG. 2) shown in the first embodiment, the corona electrode 11 was changed in order and the experiment was performed. As a comparative example of the evaluation, the same experiment was performed when one tungsten wire was used as the corona electrode.

[Sample 1]
The corona electrode 11-1 of Sample 1 is as shown in FIG.
That is, as described above, the corona electrode 11-1 has a structure in which a plurality of needle electrodes 30 are arranged in the surface direction as the tip protrusions 110 on the facing surface facing the electromechanical conversion element 20, and the needle The electrode 30 was configured such that the tip position on the side facing the electro-mechanical conversion element 20 was aligned. The needle electrode 30 was disposed in a manner perpendicular to the upper surface of the electro-mechanical conversion element 20 and the tip thereof facing the electro-mechanical conversion element 20.

The needle electrode 30 was a φ2 mm tungsten needle, the tip was processed into an R30 μm needle shape, and the processed tungsten needle electrodes 30 were bundled into φ160 mm. The electrode density was set to 25 needles / cm ² .

[Sample 2]
The corona electrode 11-2 of Sample 2 is as shown in FIG.
That is, the corona electrode 11-2 has a plurality of plate-like electrode plates 31 perpendicular to the opposing surface as the tip protrusions 110 on the opposing surface facing the electro-mechanical conversion element 20, and the electrode plates 31 are connected to the corona electrode. They were arranged parallel to each other in the in-plane direction (YY direction) of 11-2. As the electrode plate 31, a tungsten electrode plate having a plate thickness of 1 mm and a width of 0.5 mm was used. Saw blade electrodes 32 having a saw blade shape were formed at a pitch of 2 mm on the side of the electrode plate 31 facing the electromechanical conversion element 20. The electrode plate 31 was formed by stacking the tip portions of the saw-tooth electrode 32 between the adjacent electrode plates 31 while being alternately shifted by 1 mm.
The tip position of the saw blade electrode 32 on the side facing the electro-mechanical conversion element 20 is configured to be uniform, and the top surface of the electro-mechanical conversion element 20 and the tip face of the saw blade electrode 32 are arranged in a parallel positional relationship. .
The electrode density was a saw blade electrode: 50 / cm ² .

[Sample 3]
The corona electrode 11-3 of Sample 3 is as shown in FIG.
That is, the corona electrode 11-3 includes a flat plate 33 arranged so as to face the electromechanical conversion element 20, and a plurality of needle electrodes 34 arranged perpendicularly to the flat plate 33 with a space therebetween. The unit 110 is provided. As the flat plate 33, an electrode plate having a thickness of 1 mm or less formed in the size of the corona electrode 11 is used, and φ2 mm tungsten needle electrodes 34 are inserted into needle holes (not shown) at a pitch of 3 mm. The electrode density was set to 11 tungsten needles / cm ² . The needle electrode 34 is arranged in such a manner that it is orthogonal to the upper surface of the electro-mechanical conversion element 20 and has a tip facing the electro-mechanical conversion element 20, and the tip position on the side facing the electro-mechanical conversion element 20 is aligned. did. The flat plate 33 was provided with a φ0.8 mm through hole 35 through which gas flows from above between the needle electrodes. As the gas, a gas of 20% oxygen / 80% nitrogen was used.

[Production of piezoelectric element]
Next, the piezoelectric element 20 to be placed on the stage main body 130 was produced.
First, a thermal oxide film (film thickness 1 μm) is formed on a 6-inch silicon wafer 17. In this example, single crystal silicon having a (100) plane orientation was mainly used.

  As an adhesion film for the first electrode, a titanium film (thickness: 30 nm) was formed using a sputtering apparatus. The film forming temperature was 350 ° C. Note that the sputtering apparatus is provided with a plurality of targets for one chamber.

  Next, thermal oxidation is performed at 750 ° C. using RTA (Rapid Thermal Annealing), and subsequently a platinum film (thickness: 100 nm) is formed as a metal film and a SrRuO film (thickness: 60 nm) is formed as an oxide film by sputtering. The substrate was heated at 550 ° C. during the sputtering film formation.

  Next, a solution adjusted to Pb: Zr: Ti = 114: 53: 47 is prepared as an electro-mechanical conversion film, and the film is formed by spin coating.

For the synthesis of a specific precursor coating solution, lead acetate trihydrate, isopropoxide titanium and isopropoxide zirconium were used as starting materials. The crystal water of lead acetate was dehydrated after dissolving in methoxyethanol. These starting materials were weighed so that the lead amount would be excessive with respect to the stoichiometric composition of Pb (Zr _0.53 , Ti _0.47 ) O ₃ . This is to prevent so-called crystallinity degradation due to lead loss during heat treatment.

  Next, an alcohol exchange reaction and an esterification reaction were allowed to proceed in a container in which isopropoxide titanium and isopropoxide zirconium were dissolved in methoxyethanol.

  Next, these solutions were mixed to prepare a PZT precursor solution. The PZT precursor solution was 0.5 mol / l. Using this solution, a film was formed by spin coating. After the film formation, the film was dried at 120 ° C. and thermally decomposed at 500 ° C. After thermal decomposition treatment of the third layer, crystallization heat treatment (temperature: 750 ° C.) was performed by RTA (rapid heat treatment). At this time, the film thickness of PZT was 240 nm. This process was performed a total of 8 times (24 layers) to obtain a PZT film thickness of about 2 μm.

  Next, an SrRuO film (film thickness: 40 nm) was formed as an oxide film as a second electrode, and a Pt film (film thickness: 125 nm) was formed as a metal film by sputtering. Thereafter, a photoresist made by Tokyo Ohka Co., Ltd. (TSMR8800) is formed by spin coating, a resist pattern is formed by ordinary photolithography, and then the pattern shown in FIG. 11 is produced using an ICP etching apparatus (manufactured by Samco). did.

Next, as the first insulating protective film, an Al ₂ O ₃ film having a thickness of 50 nm was formed using an ALD (Atomic Layer Deposition) method. At this time, TMA (Sigma Aldrich) was used for Al as the raw material, and O3 generated by an ozone generator was used for O, and the film formation was advanced.

Thereafter, as shown in FIG. 11, contact hole portions were formed by etching. Thereafter, AL is sputtered as the third and fourth electrodes, patterned by etching, and Si ₃ N ₄ is deposited as a second insulating film to a thickness of 500 nm by plasma CVD. The electro-mechanical transducer 20 (piezoelectric) Element 20) was produced. At this time, 25 piezoelectric elements 20 were arranged in an area of 30 mm × 10 mm square in a 6-inch silicon wafer.

[Polarization treatment]
Using the corona electrode of the comparative example and the corona electrodes of Samples 1 to 3, polarization treatment was performed on the piezoelectric element 20 manufactured by the electro-mechanical transducer manufacturing apparatus.

  Since the piezoelectric element 20 used in this example uses a PZT film as the electro-mechanical conversion film, the heating temperature of the stage main body 130 during the polarization treatment is increased to 120 ° C. and up to 160 ° C. Compared with the case of raising. FIG. 16 shows the polarization amount difference (average value) of each piezoelectric element 20 after the polarization treatment.

In one corona wire electrode (comparative example), the average difference in the amount of polarization when the corona polarization treatment was performed at a heating temperature of 120 ° C. of the stage 13 was 7.0 μc / cm ^2. The average polarization amount difference during the corona polarization treatment was 9.0 μc / cm ² . Therefore, it can be seen that depolarization occurs due to the effect of both being maintained at a high temperature after the corona polarization treatment. In particular, depolarization becomes more remarkable as the temperature increases (160 ° C.).

In samples 1 to 3, the corona polarization treatment was performed under the condition where the stage 13 was heated at 120 ° C., and as a result, the average polarization amount difference was 3.0 μc / cm ² in all cases. Moreover, as a result of corona polarization treatment under the condition of the heating temperature of the stage 13 of 160 ° C., an average polarization amount difference of 2.0 μc / cm ² was obtained in all cases. Since the difference in polarization amount is considered to be good if it is 5.0 μc / cm ² or less, it can be seen that very accurate polarization processing is performed. In particular, the higher the temperature (160 ° C.), the lower the difference in polarization, which can be said to be a preferable polarization treatment method.
This is because the in-plane surface corona polarization process can reduce the variation of the in-plane polarization process, so that the substrate heating effect can be further reduced as a difference in polarization amount obtained without cracks. Conceivable.

  Therefore, when an electro-mechanical conversion element is manufactured using the corona electrodes of Samples 1 to 3 described above, it can be seen that a corona polarization process with little variation in polarization can be performed without damaging the substrate or the base film. It was.

  Incidentally, although illustration is omitted, when the electro-mechanical conversion element manufacturing apparatus shown in the second and third embodiments is further applied and the electro-mechanical conversion element manufacturing method is performed, a more stable piezoelectric element is obtained. It has also been confirmed that the element 20 can be manufactured.

  The embodiments of the present invention have been described in detail with reference to the drawings. In addition, said description is for understanding embodiment and does not limit the range of embodiment. Furthermore, the above embodiments are not mutually exclusive. Therefore, it is intended to combine the elements of different embodiments as long as no contradiction arises, and various modifications and changes are possible within the scope of the technical gist of the disclosure disclosed in the claims. .

DESCRIPTION OF SYMBOLS 10 Electro-mechanical conversion element manufacturing apparatus 11 (11-1, 11-2, 11-3) Corona electrode 12 Grid electrode 13 Stage 14 Corona electrode power supply 15 Grid electrode power supply 16 Ground wire 17 Silicon wafer 20 Electro-machine Conversion element (piezoelectric element)
21 Substrate 22 Base film 23 First electrode 24 Electro-mechanical conversion film 25 Second electrode 26 First insulating protective film 27 Contact hole 28 Third electrode 29 (Common electrode) Pad 30 Fourth electrode 31 (Individual Electrode) pad 32 second insulating protective film

JP 2006-203190 A

Claims (16)

An apparatus for manufacturing an electro-mechanical conversion element that performs polarization treatment on an electro-mechanical conversion element having a structure in which a first electrode, an electro-mechanical conversion film, and a second electrode are laminated on a substrate or a base film. There,
A corona electrode for generating a charge by corona discharge;
A stage on which the electromechanical conversion element is installed;
A grid electrode disposed between the corona electrode and the stage;
A heating mechanism for heating the electro-mechanical conversion element,
The corona electrode is an electrode having a planar shape and has a structure in which a plurality of pointed protrusions are formed on an opposing surface facing the electro-mechanical conversion element. Device manufacturing equipment. The corona electrode
On the facing surface facing the electro-mechanical conversion element, a plurality of needle electrodes are arranged in the surface direction,
2. The electro-mechanical conversion element manufacturing apparatus according to claim 1, wherein the plurality of needle electrodes have the same tip position on the side facing the electro-mechanical conversion element. The corona electrode
A plurality of plate-like electrode plates are arranged on the facing surface facing the electro-mechanical conversion element, perpendicular to the facing surface, and the electrode plates are arranged in parallel to each other,
The side of the electrode plate facing the electro-mechanical conversion element has a saw blade-shaped saw blade electrode, and the tip portions of the saw blade electrodes between adjacent electrode plates are staggered and the tip 2. The apparatus for producing an electromechanical conversion element according to claim 1, wherein the positions are uniform. The corona electrode
A flat plate arranged so as to face the electromechanical conversion element, and a plurality of needle electrodes arranged perpendicularly to the flat plate with a space therebetween,
The needle electrode has the same tip position on the side facing the electromechanical conversion element,
The electro-mechanical transducer manufacturing apparatus according to claim 1, wherein the flat plate is provided with a through hole between the needle electrodes.   The electro-mechanical conversion element manufacturing apparatus according to any one of claims 1 to 4, wherein the corona electrode is a positive electrode. The electro-mechanical conversion element manufacturing apparatus comprises:
The electro-mechanical conversion element manufacturing apparatus according to claim 1, further comprising a turning mechanism for turning the corona electrode.   The electro-mechanical conversion element manufacturing apparatus according to any one of claims 1 to 6, wherein the corona electrode is connected to a corona electrode power source having a voltage adjustment mechanism. The grid electrode is a planar electrode subjected to mesh processing,
The electro-mechanical transducer according to claim 1, wherein the stage is configured to be movable in a horizontal direction with respect to the grid electrode, and a moving distance of the stage is equal to or greater than a mesh pitch of the grid electrode. Manufacturing equipment. The stage is
A stage main body on which the electro-mechanical transducer is installed;
A stage heating unit provided with the heating mechanism;
Displacement means for displacing the distance between the stage main body and the stage heating unit;
The apparatus for manufacturing an electro-mechanical conversion element according to claim 1, wherein: Using the electro-mechanical transducer manufacturing apparatus according to any one of claims 1 to 7,
A method for producing an electro-mechanical transducer, comprising a polarization treatment step for performing polarization treatment on the electro-mechanical transducer. The stage of the electro-mechanical transducer manufacturing apparatus comprises:
A stage main body portion on which the electro-mechanical conversion element is installed, a stage heating portion provided with the heating mechanism, and a displacement means for displacing the distance between the stage main body portion and the stage heating portion,
In the polarization treatment step,
11. The method of manufacturing an electromechanical conversion element according to claim 10, wherein the displacement processing is performed while the distance between the stage heating unit and the stage main body is separated. The corona electrode of the electro-mechanical transducer manufacturing apparatus is
It is connected to a power supply for corona electrodes that has a voltage adjustment mechanism,
In the polarization treatment step,
12. The method of manufacturing an electro-mechanical conversion element according to claim 10, wherein the corona electrode power source changes a voltage applied to the corona electrode by the voltage adjusting mechanism. The grid electrode of the electro-mechanical transducer manufacturing apparatus is
It is a planar electrode with mesh processing,
The stage is configured to be movable in a horizontal direction with respect to the grid electrode,
In the polarization treatment step,
The electro-mechanical conversion element processing according to any one of claims 10 to 12, wherein the stage moves the electro-mechanical conversion element in a horizontal direction larger than a mesh pitch of the grid electrode. Method.   A piezoelectric element that has been subjected to polarization processing by the polarization processing device according to claim 1.   A droplet discharge head comprising the piezoelectric element according to claim 14.   An ink jet recording apparatus comprising the droplet discharge head according to claim 15.

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