JP2002096476A - Piezoelectric element unit and its manufacturing method, and ink-jet head using piezoelectric element unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an piezoelectric element unit which improves mounting density of the piezoelectric element obtained by a hydrothermal synthesis method and is capable of demonstrating high quality and sufficient performance. SOLUTION: A plurality of almost tabular piezoelectric element 1 are formed by the hydrothermal synthesis method on a titanium material layer 4 formed on a surface of an upright plate parts 3 almost perpendicular to a surface of a substrate 2 so that each surface of the elements is arranged in a almost parallel position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a piezoelectric element unit and an ink jet head using the same.
In particular, the present invention relates to a piezoelectric element unit using a piezoelectric element formed using a hydrothermal method, a method for manufacturing the same, and an ink jet head using the piezoelectric element unit.

[0002]

2. Description of the Related Art Conventionally, a piezoelectric element unit using a piezoelectric element has been frequently used for a head of an ink jet printer (hereinafter, referred to as an ink jet head). As such a piezoelectric element, for example, a ceramic mainly containing lead zirconate titanate (Pb (Zr, Ti) O ₃ , hereinafter referred to as PZT) is preferably used.

The above-described piezoelectric element made of PZT is generally manufactured as a plate-shaped or lump-shaped sintered body, and cut and polished according to a required size. However, ceramics such as PZT are very hard and brittle, causing a problem that processing is difficult. Specifically, in order to use it for an application requiring a small piezoelectric element such as the above-mentioned ink jet head, P
It is necessary to cut and polish ZT to a very small size. However, if PZT is made to be too small, breakage will occur during polishing or bonding, and the yield of piezoelectric elements will decrease, resulting in higher costs. Will do. therefore,
Usually, PZT is often used with a size (length of one side) of 1 mm or more and a thickness of 100 μm or more.

[0004] As a method of manufacturing a piezoelectric element made of PZT, in addition to the method of manufacturing the above-described sintered body, a chemical vapor deposition (chemical vapor deposition) method is used.
ion method, hereinafter referred to as a CVD method), or a physical vapor deposition method (physical vapor deposition).
The method is referred to as a PVD method or a sol-gel method.

However, all of these methods lack practicality. Specifically, the CVD method has problems such as an increase in the scale of manufacturing equipment, difficulty in controlling the composition of PZT, and an expensive raw material. In the PVD method, thermal strain is generated by raising the temperature of the substrate, and the PZT quality is reduced based on the thermal strain.
However, there are problems such as generation of oxygen defects, difficulty in controlling the composition of PZT, and slow PZT growth time. In the sol-gel method, when printing and firing a grain sheet on a base material in a desired shape, there is a problem such as a change in composition due to the firing, shrinkage of the sheet, etc., and the quality of PZT is reduced. There is a point.

In recent years, a method called a hydrothermal method (or a hydrothermal synthesis method) has attracted attention as a method of manufacturing a fine piezoelectric element by PZT. This hydrothermal method specifically includes a lead ion (Pb ^{2+ and} others) and a zirconium ion (Zr
PH 14 containing ²⁺ other) and titanium ions (Ti ⁴⁺ other)
This is a method in which a PZT layer is formed on the surface of a titanium substrate by immersing the titanium substrate in the above-mentioned strongly alkaline processing liquid and subjecting the substrate to pressure and heat treatment. In this hydrothermal method, an autoclave (pressure cooker / pressure cooker) can be used as a production facility, so there is no need to prepare a large-scale and high-cost facility, and a fine layer can be formed in a shorter time. In addition, there is an advantage that layers of various shapes can be formed by changing the shape of the titanium substrate.

As a technique for manufacturing a piezoelectric element made of PZT by using the above-mentioned hydrothermal method, for example, International Publication WO97 / 03834 or JP-A-8
And the technology disclosed in US Pat.

In the technology disclosed above, lead nitrate (P
b (NO ₃ ) ₂ ) aqueous solution, zirconium oxychloride (Z
rOCl ₂ · 8H ₂ O) aqueous solution of titanium tetrachloride (TiC
l ₄ ) The substrate is immersed in a reaction solution prepared by mixing an aqueous solution and an aqueous potassium hydroxide solution, and subjected to hydrothermal treatment at 150 ° C.

In the technique disclosed in the above, the substrate is immersed in a treatment solution prepared by mixing an aqueous solution of lead nitrate, an aqueous solution of zirconium oxychloride, an aqueous solution of titanium tetrachloride, and an aqueous solution of potassium hydroxide, and the PZT nucleus is firstly autoclaved. After the formation, a treatment liquid having the same composition but a different composition is prepared, and the PZT layer is formed in an autoclave using the treatment liquid.

[0010]

However, any of the above-mentioned techniques based on the hydrothermal method have problems in using them for manufacturing a piezoelectric element unit used for an ink jet head or the like.

According to the above-mentioned hydrothermal method, a fine element shape, particularly a layered shape can be efficiently formed, so that a fine PZT piezoelectric element can be produced, but the obtained piezoelectric element has a low piezoelectric constant. There is a disadvantage in that the efficiency is reduced to a fraction of that of a PZT piezoelectric element obtained by sintering, and the efficiency of the piezoelectric element is low. Therefore, when the PZT piezoelectric element used in the ink jet head is downsized and a higher density mounting arrangement is attempted, sufficient efficiency of the piezoelectric element (conversion efficiency) is low, so that sufficient ejection energy cannot be obtained. Piezoelectric elements cannot be put to practical use. Therefore, in order to manufacture a piezoelectric element unit, it is necessary to increase the mounting density of PZT piezoelectric elements obtained by a hydrothermal method.

However, in the piezoelectric element unit manufactured by any of the above techniques, the P
Only the piezoelectric element made of ZT is formed. for that reason,
Since the PZT piezoelectric elements are arranged on the same plane, the mounting density is limited, and the pitch between the PZT piezoelectric elements is reduced, which causes problems such as crosstalk and leakage. Therefore, any of the above techniques has a problem that a PZT piezoelectric element unit having sufficient performance cannot be manufactured.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a piezoelectric element manufactured by a hydrothermal method arranged in parallel with each other so that a sufficient area of the piezoelectric element can be obtained even in high-density mounting. , And stable ejection is realized. An object of the present invention is to provide a piezoelectric element unit capable of exhibiting higher quality and sufficient performance by effectively using a hydrothermal method capable of efficiently producing a fine piezoelectric element although the piezoelectric element constant is reduced. Another object of the present invention is to provide an inkjet head using the piezoelectric element unit and a method of manufacturing the same.

[0014]

In order to solve the above-mentioned problems, a piezoelectric element unit according to the present invention is a piezoelectric element unit comprising a plurality of substantially flat piezoelectric elements, wherein the plurality of piezoelectric elements are Are formed by a hydrothermal method and are arranged in parallel so that their surfaces have a substantially parallel positional relationship.

According to the above structure, the substantially flat piezoelectric element formed by the hydrothermal method is not laminated (or formed so as to be attached) on a flat substrate surface as in the related art, but is flat. Are arranged in parallel in a state of standing substantially upright on the surface of the substrate.

A piezoelectric element manufactured by a hydrothermal method has an advantage that a fine element shape, particularly a layered shape, can be efficiently formed, but it has an advantage over a piezoelectric element manufactured by sintering. Since the piezoelectric constant (piezoelectric element constant) is small, there is a disadvantage that the efficiency as a piezoelectric element is poor. For example, when the piezoelectric element is made of lead zirconate titanate (hereinafter referred to as P
When the piezoelectric element is made of a ceramic material whose main component is ZT), the piezoelectric constant of the piezoelectric element formed by the hydrothermal method is several times smaller than that of the piezoelectric element obtained by sintering.

On the other hand, according to the above configuration, the substantially flat piezoelectric elements formed by the hydrothermal method are arranged in parallel in a state of being substantially erected on a flat substrate surface. Compared to the conventional configuration where the element is directly attached to the substrate,
The mounting density of the piezoelectric element can be improved. As a result, it is possible to sufficiently cover the disadvantages of the piezoelectric element formed by the hydrothermal method by improving the mounting density,
A high-performance piezoelectric element unit can be obtained.

In the hydrothermal method, polarization occurs in PZT during film formation, so that the polarization treatment conventionally performed in oil near the Curie point (300 ° C.) after PZT baking becomes unnecessary. Therefore, the manufacturing process of the piezoelectric element made of the ceramic material containing PZT as a main component is simplified, and the stress on the PZT piezoelectric element due to the thermal stress at the time of the polarization treatment can be prevented.

Preferably, the piezoelectric element unit has a plurality of upright portions formed substantially perpendicular to the surface of the substrate, and the piezoelectric element is more preferably formed on the surface of the upright portion.

According to the above arrangement, the cross section of the unit substrate composed of the substrate and the plurality of upright portions is comb-shaped.
The configuration in which the surfaces of the substantially flat piezoelectric elements are arranged in parallel so as to have a substantially parallel positional relationship can be integrated into one piezoelectric element unit in a stable state. Therefore, the structure of the piezoelectric element unit having a high mounting density can be further stabilized.

The expression that the piezoelectric element is formed on the surface of the upright portion means that the surface of the upright portion is made of titanium or a titanium-containing layer containing titanium formed in a predetermined shape. This means that the piezoelectric element is selectively formed by the method.

In the piezoelectric element unit according to the present invention, it is more preferable that the end of the piezoelectric element is formed so as to be located inside the end of the upright plate portion with an interval.

According to the above configuration, the surface area of the piezoelectric element is slightly smaller than the surface area of the upright portion. An upright portion of the piezoelectric element unit is sandwiched between a substrate and a top plate, and a piezoelectric element is formed on a surface of the upright portion, and an end of the piezoelectric element is an end of the upright portion. It is located inside at an interval from. That is, the piezoelectric element is formed on the surface of the standing plate portion so as to be separated from the substrate and the top plate sandwiching the standing plate portion. That is, since the piezoelectric element is not directly in contact with the substrate and the top plate forming the upper and lower surfaces of the piezoelectric element unit, it is not fixed to the substrate and the top plate. Therefore, it is possible to reduce the leakage between the piezoelectric elements via the substrate and the like, and to suppress the propagation of the stress from the piezoelectric element to the substrate and the top plate, thereby reducing the crosstalk caused by the stress propagation. can do.

The position where the end of the piezoelectric element is formed may be appropriately set so as to reduce crosstalk between the piezoelectric elements due to leakage and stress propagation, and there is no particular limitation. A position where the distance between the end of the vertical plate and the end of the standing plate portion is constant is more preferable. That is, it is more preferable that the end of the piezoelectric element is formed so as to be located inside at an interval from the end of the standing plate.

In the piezoelectric element unit of the present invention, it is more preferable that the surface of the piezoelectric element is flattened.

According to the above configuration, since the PZT or the like is produced by crystal growth in the hydrothermal method, irregularities are formed on the surface of the obtained PZT piezoelectric element. Therefore, by flattening the surface of the piezoelectric element, the piezoelectric element can be balanced.

The piezoelectric element may further have a coat layer for flattening the surface. Thereby, the surface of the PZT piezoelectric element having unevenness can be flattened using the coat layer having good workability.
Therefore, it is possible to omit the flattening process of the piezoelectric element or to significantly reduce the time required for the flattening process.

As the above-mentioned coat layer, it is preferable to use PZT using a sol-gel method, an organic material or an inorganic material. This makes it possible to manufacture the coat layer that is the outermost surface of the piezoelectric element with good workability so as to have a desired surface roughness.

It is more preferable that the piezoelectric element unit has a configuration in which the piezoelectric element is formed on the opposite surface of the adjacent standing plate portion, and a space is formed between the piezoelectric elements.

According to the above configuration, one air chamber is formed by forming a space between the pair of piezoelectric elements formed on the opposing surfaces of the adjacent standing plate portions. Therefore, the piezoelectric effect of the piezoelectric element is exerted outward from the air chamber. For example, if the piezoelectric element unit according to the present invention is used for an ink jet head, by providing an ink pressurizing chamber between the air chambers, it is possible to avoid direct contact between the ink and the piezoelectric element. . This facilitates protection of the piezoelectric elements, facilitates insulation between the piezoelectric elements, and prevents crosstalk.

In order to solve the above-mentioned problems, a piezoelectric element unit according to the present invention is a piezoelectric element unit having a plurality of piezoelectric elements arranged, wherein the plurality of piezoelectric elements have a length in a primary direction by a hydrothermal method. , And are arranged in parallel so that their longitudinal directions are substantially parallel to each other.

According to the above structure, the substantially cylindrical piezoelectric element formed by the hydrothermal method is not laminated (or formed so as to be attached) on a flat substrate surface as in the related art. By being laminated (or formed to be attached) on the surface of the cylindrical support member, they are arranged in parallel in a state of forming a substantially cylindrical piezoelectric element.

That is, since the surface having a large area is curved into a substantially cylindrical state, the mounting density of the piezoelectric element can be further improved as compared with the conventional configuration in which a substantially flat piezoelectric element is directly attached to a substrate. it can. As a result, it is possible to obtain a high-performance piezoelectric element unit that sufficiently covers the disadvantages (poor efficiency of the piezoelectric element) of the piezoelectric element manufactured by the hydrothermal method by improving the mounting density.

Since the piezoelectric element itself has a substantially cylindrical shape, for example, when the piezoelectric element unit according to the present invention is used as an ink jet head, the ejection efficiency and the rigidity can be increased.

In the present invention, "having a length in the primary direction" means having a shape extending in one direction, for example, a rod-like shape.

An ink jet head according to the present invention is characterized by using the above-described piezoelectric element unit according to the present invention to solve the above problems.

According to the above structure, as described above, it is possible to obtain an ink jet head using a high-performance piezoelectric element unit that sufficiently covers the disadvantages of the piezoelectric element manufactured by the hydrothermal method by improving the mounting density. it can. Therefore, an ink jet head using the piezoelectric element can be made very high quality and low cost.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
In order to solve the above problems, a titanium material layer forming step of forming a plurality of titanium material layers made of titanium or a material containing titanium in a predetermined shape on a substrate made of a material not containing titanium, A piezoelectric element forming step of selectively forming a plurality of substantially flat piezoelectric elements made of a ceramic material containing lead zirconate titanate (PZT) as a main component by a hydrothermal method; A piezoelectric element arranging step of arranging the piezoelectric elements in parallel so that their surfaces have a substantially parallel positional relationship.

According to the above configuration, the piezoelectric element (hereinafter, referred to as P) made of a ceramic material mainly composed of PZT having a substantially flat plate shape is used.
A ZT piezoelectric element) is collectively formed on one substrate, and then the PZT piezoelectric elements are arranged in parallel such that the surfaces of the PZT piezoelectric elements are in a substantially parallel positional relationship to form a piezoelectric element unit. For this reason, the mass productivity of the PZT piezoelectric element is improved.
In addition, since a plurality of piezoelectric elements are collectively formed on one substrate, it is possible to greatly reduce the clearance between the piezoelectric elements when forming the piezoelectric elements, and to increase the resolution when forming the piezoelectric elements. That is, high resolution can be achieved.

In the method of manufacturing the piezoelectric element unit, in the piezoelectric element arranging step, a supporting member for supporting the piezoelectric elements with the piezoelectric elements facing each other is used, and after fixing the piezoelectric elements with the piezoelectric elements facing each other, Preferably, the support member is removed.

According to the above configuration, each piezoelectric element can be fixed and handled with the piezoelectric elements facing each other. Before the small piezoelectric elements are assembled together, they have problems such as low strength and lack of handleability, resulting in poor workability and workability. Therefore, by using the support member, problems of workability and workability can be solved, and the piezoelectric element unit according to the present invention can be efficiently manufactured.

In the method of manufacturing the piezoelectric element unit, in the piezoelectric element arranging step, the piezoelectric element is arranged on the surface of the standing plate portion and fixed and supported, and then the standing plate portion is substantially flattened by a diffusion bonding method. It is more preferable that a plurality of such substrates be erected and integrated on the surface of a simple substrate.

According to the above configuration, the diffusion bonding method is used to
A unit substrate having a comb-shaped cross section can be formed. Therefore, the rigidity of the piezoelectric element unit obtained by stably arranging the configurations of the flat plate-shaped piezoelectric elements arranged in parallel so that their respective surfaces have a substantially parallel positional relationship can be made extremely high. Moreover, by performing the diffusion bonding method, annealing is performed in parallel with the piezoelectric element made of PZT, so that the performance of the piezoelectric element is improved. As a result, for example, when the piezoelectric element unit is used for an inkjet head, the ejection performance can be improved by a synergistic effect.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
In order to solve the above problems, the surface of each upright portion of the unit substrate having a plurality of upright portions formed substantially perpendicular to the surface of the substantially flat substrate, made of a material not containing titanium,
A step of forming a plurality of titanium material layers made of titanium or a material containing titanium in a predetermined shape, a step of forming a titanium material layer on the surface of the upright portion, and forming a zirconate titanate on the surface of the upright portion by a hydrothermal method. A vertical plate portion piezoelectric element forming step of selectively forming a plurality of substantially flat piezoelectric elements made of a ceramic material containing lead (PZT) as a main component.

According to the above configuration, the substantially flat piezoelectric element is formed on the surface of the standing plate portion of the unit substrate having a comb-shaped cross section, so that the unit substrate on which the piezoelectric element is formed is formed. Can be directly used as one unit. Therefore, the step of arranging a plurality of piezoelectric elements in parallel can be omitted, and the manufacturing steps of the piezoelectric element unit can be simplified. Further, since the unit substrate has a structure having a plurality of standing portions, the structure of the piezoelectric element unit can be further stabilized. In particular, when the piezoelectric element unit according to the present invention is used for an ink jet head, the rigidity of the ink pressurizing chamber can be improved, and a head having a high ejection frequency can be obtained.

In the step of forming the surface titanium material layer on the standing plate portion, the end of the titanium material layer is formed so as to be located inside the end portion of the standing plate portion at an interval. Is more preferred.

According to the above configuration, the surface area of the piezoelectric element formed on the titanium material layer is slightly smaller than the surface area of the standing plate portion. Since it is not in direct contact with the top plate, it is not fixed to the substrate and the top plate. Therefore, a high-quality piezoelectric element unit free from problems such as crosstalk and leakage can be manufactured.

The position where the end of the titanium material layer is formed may be appropriately set so as to reduce crosstalk due to leakage between the piezoelectric elements and stress propagation, and there is no particular limitation. A position where the distance between the end of the element and the end of the upright portion is constant is more preferable. That is, it is more preferable that the end portion of the titanium material layer is formed so as to be located inside at an interval from the end portion of the standing plate portion.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
In order to solve the above-mentioned problem, a support member made of titanium-free material and formed on a substantially cylindrical support member having a length in the primary direction, a titanium material layer made of titanium or a material containing titanium is provided. Layer forming step and lead zirconate titanate (PZT) on the titanium material layer by hydrothermal method
A support member piezoelectric element forming step of selectively forming a substantially flat piezoelectric element made of a ceramic material containing as a main component,
A support member removing step of obtaining the substantially cylindrical piezoelectric element by removing the support member, and a substantially cylindrical piezoelectric element in which a plurality of the substantially cylindrical piezoelectric elements are arranged in parallel so that their longitudinal directions are substantially parallel to each other. And an arrangement step.

According to the above configuration, a substantially tubular piezoelectric element made of PZT, which cannot be manufactured by the conventional sintering method, can be easily manufactured by taking advantage of the hydrothermal method. Moreover, since these tubular PZT piezoelectric elements have a length in the primary direction, they are arranged so that their longitudinal directions are substantially parallel to each other, thereby further improving the mounting density of the PZT piezoelectric elements. Can be. Further, since the piezoelectric element itself has a substantially cylindrical shape, for example, when the piezoelectric element unit according to the present invention is used as an ink jet head, a piezoelectric element having high ejection efficiency and high rigidity can be obtained.

The method of manufacturing the piezoelectric element unit may further include a step of flattening the surface of the piezoelectric element by cutting with a diamond cutting tool.

By cutting with a diamond cutting tool, it is possible to greatly shorten the processing time as compared with other processing methods, and to efficiently perform flat processing even on coarse grain boundaries. Become.

The method for manufacturing the piezoelectric element unit further includes a step of providing a coat layer for flattening the surface of the piezoelectric element on the surface of the first layer mainly composed of PZT formed by a hydrothermal method. May be. Thereby, the surface of the PZT piezoelectric element having unevenness can be flattened using the coat layer having good workability. Therefore,
It is possible to greatly reduce the time required for the flattening process of the piezoelectric element or to omit the machining process.

As the above-mentioned coat layer, for example, PZT using a sol-gel method, an organic material or an inorganic material can be used. This makes it possible to manufacture the coat layer that is the outermost surface of the piezoelectric element with good workability so as to have a desired surface roughness.

Incidentally, the high-density multi-channel array / pulse drop applying apparatus disclosed in Japanese Patent Publication No. 6-6375 is apparently similar in structure to the piezoelectric element unit in the present invention. However, since the piezoelectric element of the high-density multi-channel array / pulse drop applying apparatus is a bulk element manufactured by sintering, it can be formed only in a columnar shape and cannot be formed in a fine flat plate shape. The ejection principle of the device is to use the shear mode distortion of the piezoelectric element, whereas the piezoelectric element unit of the present invention uses the bending mode distortion, so that both are different in principle. .

A bulk piezoelectric element cannot be manufactured by the hydrothermal method, and the manufactured piezoelectric element cannot be used for a high-resolution ink jet head as in the present invention. Further, the present invention, since the flat piezoelectric element obtained by the hydrothermal method is integrated and erected with the upright portion, it is possible to realize a sufficient mounting density of the piezoelectric element, It is fundamentally different from the technology in the publication.

[0057]

FIG. 1 shows an embodiment of the present invention.
This will be described below with reference to FIG.

The piezoelectric element unit according to the present invention comprises a lead zirconate titanate (PZT:
A piezoelectric element made of a ceramic material containing Pb (Zr, Ti) O ₃ ) as a main component is mounted at a high density. As shown in FIG.
Are arranged in parallel so that their surfaces have a substantially parallel positional relationship. Specifically, as the unit substrate serving as a substrate of the piezoelectric element unit, a unit substrate including a substrate 2 and a plurality of upright portions 3 formed substantially perpendicular to the surface of the substrate 2 is used. Then, a titanium material layer 4 is formed on the surface of the standing portion 3 of the unit substrate, and the PZT piezoelectric element 1 is formed on the surface of the titanium material layer 4. In addition, as the ceramic material for the piezoelectric element, barium titanate (BaTiO ₃ ), strontium titanate (Sr
TiO ₃ ) or the like can be used.

The PZT piezoelectric element 1 manufactured by the hydrothermal method has an advantage that a fine element shape, particularly a layered shape, can be efficiently formed, but a PZT obtained by sintering.
There is a disadvantage that the piezoelectric element constant (piezoelectric constant) is a fraction of that of a T piezoelectric element, and the efficiency of the piezoelectric element is low. Therefore, in order to obtain a piezoelectric element unit having sufficient performance using the PZT piezoelectric element 1 formed by the hydrothermal method, the PZT piezoelectric element 1 on the unit substrate is required.
It is necessary to improve the mounting density of the device.

Conventionally, as shown in FIG. 14, a substantially plate-shaped piezoelectric element 101 made of PZT has been formed so as to be attached (laminated) to the surface of a flat substrate 102. But,
In the present invention, as shown in FIG.
Are arranged side by side in a state of standing substantially upright on the surface of the flat substrate 2. As a result, the mounting density of the PZT piezoelectric element 1 can be sufficiently improved as compared with the conventional configuration (FIG. 14), so that the high efficiency of the PZT piezoelectric element 1 is sufficiently covered. A piezoelectric element unit can be obtained.

In this embodiment, a case where the piezoelectric element unit according to the present invention is applied to an ink jet head will be described.

[Embodiment 1] As shown in FIG. 3, in this embodiment, the piezoelectric element unit is applied to an ink jet head. At this time, the end of the PZT piezoelectric element 1 is It is preferable that the piezoelectric element 1 made of PZT is formed on the surface of the titanium material layer 4 formed on the surface of the standing plate portion 3 so as to be arranged at a position on the inside of the end plate at a fixed interval.

In the ink jet head shown in FIGS. 3 and 4, a vertical plate portion 3 is formed substantially perpendicular to the substrate 2, and a PZT piezoelectric element 1 is formed on the surface of the vertical plate portion 3. A nozzle port 5 for discharging ink and an ink reservoir (not shown) are formed on the substrate 2, and the top plate 7 (nozzle) is opposed to the unit substrate via the PZT piezoelectric element 1 and the upright plate 3. Plate). Therefore, the space between the plurality of upright portions 3 sandwiched between the substrate 2 and the top plate 7 forms the ink pressurizing chamber 8 in the ink jet head. And PZ
A surface electrode 9 is formed on the surface of the piezoelectric element 1 made of T.

FIG. 4 is a sectional view of the ink jet head as viewed from the nozzle port 5 side. As shown in FIG.
Since the standing plate portion 3 stands upright, the unit substrate has a comb-shaped cross section, and the space formed between the standing plate portions 3 becomes the ink pressurizing chamber 8. A surface electrode 9 is formed on the surface of the piezoelectric element 1 made of PZT, and a titanium material layer 4 is formed between the piezoelectric element 1 made of PZT and the standing plate portion 3. It becomes the back electrode. The standing plate portion 3 has an elastic structure, and the titanium material layer 4
The standing plate portion 3, the surface electrode 9, and the PZT piezoelectric element 1 constitute a piezoelectric operating portion 10. Note that lead wires (not shown) and the like are connected to the titanium material layer 4 and the surface electrode 9. Further, the space between the adjacent standing plate portions 3 is the ink pressurizing chamber 8.
Therefore, the titanium material layer 4, the PZT piezoelectric element 1, and the surface electrode 9 provided on the surface of the standing plate portion 3 are prevented from directly contacting the ink in the ink pressurizing chamber 8. An insulating layer 11 covering the piezoelectric element 1 and the surface electrode 9 is formed. By forming the insulating layer 11, an effect of preventing leakage between the PZT piezoelectric elements 1 is further obtained.

The piezoelectric element unit according to the present invention configured as described above operates in the bending mode. Specifically, for example, the PZT of an ink jet head (piezoelectric element unit) having a structure as shown in FIGS.
The titanium material layer 4 and the surface electrode 9 are
When a predetermined voltage is applied through the
The piezoelectric element 1 made of T contracts and the piezoelectric element 1 made of PZT bends, and the upright plate 3 also bends accordingly.
The ink pressurizing chamber 8 between them is narrowed. As a result, the volume of the ink pressurizing chamber 8 rapidly decreases, so that ink droplets are ejected from the nozzle port 5.

The PZT piezoelectric element 1 is a substantially flat PZT element formed by a hydrothermal method, and its shape and thickness are not limited. It is set appropriately. However, the surface area of the PZT piezoelectric element 1 is slightly smaller than the surface area of the standing plate portion 3. That is, the ends of the PZT piezoelectric element 1 are spaced apart from the surfaces of the substrate 2 and the top plate 7 by a predetermined distance. This is to reduce the occurrence of a leak or the like between the PZT piezoelectric elements 1 via the substrate 2, the top plate 7, and the like.

Further, since the surface area of the piezoelectric element 1 made of PZT is slightly smaller than the surface area of the upright portion 3, the piezoelectric element 1 made of PZT is directly provided on the upper and lower surfaces (substrate 2 and top plate 7) of the ink jet unit. You will not be in contact. Therefore, the ends of the PZT piezoelectric element 1 are not fixed to the substrate 2 and the top plate 7. As a result, P
Crosstalk due to stress propagation from the ZT piezoelectric element 1 can be reduced.

The surface electrode 9 is not particularly limited as long as it constitutes the piezoelectric operating portion 10 together with the PZT piezoelectric element 1 and the standing plate portion 3, but usually aluminum or the like is preferably used. Further, the titanium material layer 4 is made of a material containing titanium or only titanium, and is not particularly limited as long as it functions as an electrode. Although the size and thickness of the surface electrode 9 and the titanium material layer 4 are not particularly limited, for example, the titanium material layer 4 may have a thickness of about 0.1 μm. Surface electrode 9
The method for forming the titanium material layer 4 is not particularly limited. For example, an aluminum vapor deposition method is preferably used for forming the surface electrode 9, and a sputtering method is preferably used for forming the titanium material layer 4. As described above, the PZT piezoelectric element 1
Can be formed corresponding to the shape of.

The material of the insulating layer 11 is not particularly limited as long as it can exert an insulating effect, but a polyimide insulating film or the like is preferably used. As a method for forming the polyimide insulating film, a printing method or the like is used. Insulating layer 1
The film thickness of 1 is not particularly limited as long as it is appropriately set so as to exhibit an insulating effect.

Further, a platinum (Pt) film may be formed between the standing plate portion 3 and the titanium material layer 4 in order to improve the adhesion of the PZT piezoelectric element 1 to the standing plate portion 3. As a method for forming the platinum film, a sputtering method is preferably used, but it is not particularly limited. Further, the thickness of the platinum film may be appropriately set, and is not particularly limited.

The upright portion 3 may be formed integrally with the substrate 2 as a single body, or may be formed separately from the substrate 2. That is, the standing plate portion 3 may be formed by processing the substrate 2, or the standing plate portion 3 may be formed separately from the substrate 2. For example, in the unit substrate shown in FIG. 1, a vertical plate portion 3 is formed by subjecting a substrate 2 made of an elastic material to groove processing. Alternatively, as will be described later, the upright portion 3 is separately formed using a material similar to the substrate 2 or a material that can be bonded to the substrate 2, and the upright portion 3 is formed later.
May be joined to the substrate 2 to form a unit substrate.

That is, as shown in FIG. 4, the substrate 2 used in the present invention may have a plurality of upright portions 3 so that at least its cross section has a comb shape. With the configuration including the plurality of upright portions 3, the configuration in which the flat-plate-shaped piezoelectric elements 1 made of PZT are arranged in parallel can be stably combined into one unit. Therefore, the structure of the piezoelectric element unit having a high mounting density of the PZT piezoelectric element 1 can be further stabilized. In particular, in a configuration where the standing plate portion 3 and the substrate 2 are integrated, the rigidity of the entire inkjet head as a piezoelectric element unit is improved. As a result, the ejection performance of the inkjet head can be improved.

It is preferable that the material of the standing plate portion 3 and the substrate 2 does not contain titanium. However, the shape and size of the standing plate portion 3 and the substrate 2 are not particularly limited as long as they can be used as a piezoelectric element unit (inkjet head).
In the present invention, the PZT piezoelectric element 1 is formed by a hydrothermal method. However, as described later, in the hydrothermal method, PZT is selectively formed at a certain position on the titanium surface. That is, it is not preferable that titanium is contained in the standing plate portion 3 or the substrate 2 because PZT cannot be selectively formed.
As a preferable material of the standing plate portion 3 and the substrate 2, specifically, nickel (Ni) or the like is given.
For example, it may be about 50 μm.

Next, a method of manufacturing the piezoelectric element unit (inkjet head) having the above-described configuration will be described.

The method of manufacturing the piezoelectric element unit having the above structure can be roughly classified into (I) a method in which the substrate 2 and the standing plate portion 3 are integrated from the beginning, and (II) a method in which the substrate 2 is And a manufacturing method in the case where the standing plate portion 3 is erected.

First, a method of manufacturing the piezoelectric element unit (I) will be described with reference to FIG. in this way,
Since the substrate 2 and the upright portion 3 are integrated from the beginning,
A piezoelectric element unit can be formed by forming a titanium material layer 4 on a predetermined portion of the standing plate portion 3 and then forming a PZT layer, that is, a PZT piezoelectric element 1 by a hydrothermal method.

Here, the hydrothermal method will be described in detail. First, a strongly alkaline treatment liquid containing lead (Pb), zirconium (Zr) and titanium (Ti) having a pH of 14 or more is prepared. If the substrate is immersed and subjected to heat and pressure treatment, PZT is selectively formed only on the portion of the Ti surface. At this time, polarization occurs in a direction perpendicular to the surface of the substrate, that is, in the PZT film forming direction, so that the polarization processing conventionally performed after the piezoelectric element unit is formed can be omitted.

In the method (I) for manufacturing a piezoelectric element unit, first, a unit substrate made of an elastic material and provided with a plurality of standing plates 3 in advance is prepared (FIG. 5A and FIG. 1).
reference). Such a unit substrate, as described above,
For example, it can be easily formed by groove processing for forming a predetermined groove on a flat substrate. Of course, other methods may be used. Although a specific method of the groove processing is not particularly limited, for example, a mechanical processing or an etching method is used.

Next, as shown in FIG. 5A, the unit substrate having the plurality of upright portions 3 formed as described above is made of titanium or a material containing titanium where PZT is to be formed. The titanium material layer 4 is formed. As the method for forming the titanium material layer 4 at this time, the above-described sputtering method is suitably used.

In the step of forming the titanium material layer 4, it is preferable that the end of the titanium material layer 4 is arranged at a position inside the end of the standing plate portion 3 by a predetermined distance. According to this, since the surface area of the titanium material layer 4 is smaller than the surface area of the upright portion 3, the PZT piezoelectric element 1 selectively formed on the titanium material layer 4 also has the upper surface of the piezoelectric element unit and It is formed so as to be at a certain distance from the lower surface. Therefore, a high-quality piezoelectric element unit free from problems such as crosstalk and leakage can be manufactured.

Next, as shown in FIG. 5B, a PZT piezoelectric element 1 composed of a PZT layer is selectively formed on the titanium material layer 4 on the surface of the upright portion 3 by a hydrothermal method. . As a specific method of the hydrothermal method, a known method is used. For example, International and published WO97 / 03834 discloses, as disclosed in JP-A-8-306980, lead nitrate (Pb (NO _{3) 2)} aqueous solution of zirconium oxychloride (ZrOCl ₂ · 8H ₂ O) solution The unit substrate is immersed in a strongly alkaline reaction solution prepared by mixing an aqueous solution of titanium tetrachloride (TiCl ₄ ) and an aqueous solution of potassium hydroxide, and is subjected to hydrothermal treatment by an autoclave. The conditions of the autoclave for performing the above hydrothermal treatment and other conditions are not particularly limited.

As shown in FIG. 5 (c), a surface electrode 9 is further applied to each of the substantially flat PZT-made piezoelectric elements 1 made of a ceramic material containing PZT as a main component. Form. The method of forming the surface electrode 9 is not particularly limited, and examples thereof include a method of forming an electrode by oblique deposition. Like the PZT piezoelectric element 1, the surface electrode 9 is also formed such that its ends are separated from the substrate 2 and the top plate 7. Therefore, as shown in FIG. 5C and the like, it is preferable that the surface electrode 9 is formed to be smaller than the surface area of the piezoelectric element 1 made of PZT.

In the method (I), the PZT piezoelectric element 1 is formed on the unit substrate having the standing plate portion 3 at a time. It can be used as one piezoelectric element unit. Therefore, the manufacturing process of the piezoelectric element unit can be simplified. Also, since the original unit substrate has a structure having a plurality of upright portions 3,
The structure of the piezoelectric element unit using the unit substrate can be further stabilized. In particular, when the piezoelectric element unit is used for an ink jet head, the rigidity of the ink pressurizing chamber 8 can be improved, so that an ink jet head having a high ejection frequency can be obtained.

Next, a method of manufacturing the piezoelectric element unit (II) will be described with reference to FIG. in this way,
Since the substrate 2 and the plurality of upright portions 3 are separate bodies, first, after the titanium material layer 4 is formed, the upright portion 3 on which the PZT layer is formed by the hydrothermal method is obtained. Standing plate 4 is attached to substrate 2
To form a unit substrate, and a piezoelectric element unit is formed using the unit substrate. Specifically, first, as shown in FIG. 6A, a shape to be the standing plate portion 3 is formed on an elastic substrate 15 made of nickel or the like. In FIG. 6A, a substantially rectangular upright portion 3 is connected to the main frame. Then, a titanium material layer 4 is formed in a predetermined shape at a portion where PZT is to be formed.

Then, as shown in FIG. 6B, a PZT layer, that is, a PZT piezoelectric element 1 is selectively formed on the titanium material layer 4 by a hydrothermal method. Thereafter, after forming a surface electrode 9 (not shown), as shown in FIG. 6C, the standing plate portion 3 on which the titanium material layer 4, the PZT piezoelectric element 1, and the surface electrode 9 are formed is removed from the main frame. Separate and make the upright portion 3 alone. Next, as shown in FIG. 6D, the standing plate portion 3 is erected on the substrate 2 so that the plurality of PZT piezoelectric elements 1 have a mutually parallel positional relationship. The standing plates 3 are arranged in parallel.

Here, as shown in FIG. 6E, when the upright portions 3 are juxtaposed on the substrate 2, the upright portions 3 and the substrate 2 are integrated using a diffusion bonding method. Is preferred. Diffusion bonding is a method in which a metal-based material is brought into close contact with a bonding surface and heated to near the softening point of the material in a vacuum or reducing atmosphere, such as in a vacuum furnace or hydrogen furnace, to cause diffusion of atoms through the bonding surface. It is a joining method. In the diffusion bonding method, since the strength of the bonding portion between the standing plate portion 3 and the substrate 2 can be further improved, the rigidity of the piezoelectric element unit can be made extremely high.

The diffusion bonding method described above can be applied not only to the case of the same kind of metal but also to the bonding between different kinds of metals. Therefore, even if the substrate 2 and the upright portion 3 are made of different materials, they may be joined with sufficient strength in some cases. Therefore, the degree of freedom in manufacturing the piezoelectric element unit can be improved.

Further, in parallel with the implementation of the diffusion bonding method, P
Annealing (annealing) for ZT piezoelectric element 1
It can be performed. Since the performance of the PZT piezoelectric element 1 made of a ceramic material containing PZT as a main component is improved by annealing, when the piezoelectric element unit is used for an ink jet head, for example, the ejection performance can be improved by the synergistic effect. .

In the method (II), one elastic substrate 1
In order to form the piezoelectric element unit after forming the PZT piezoelectric element 1 at a time using
The mass productivity is improved. Moreover, since a plurality of PZT piezoelectric elements 1 are formed on one elastic substrate 15, PZT
When the piezoelectric element 1 is formed, the clearance between the PZT piezoelectric elements 1 can be greatly reduced, and there is an advantage that the PZT piezoelectric element 1 can be formed with high resolution.

It is highly preferable that the surface of the PZT piezoelectric element 1 is flattened. In the hydrothermal method, PZT is produced by crystal growth, so that the surface of the piezoelectric element 1 made of PZT has irregularities due to the grain boundaries of the grown crystal and has a rough surface. Therefore, the PZT piezoelectric element 1 is made uniform by flattening the surface.

The flattening method at this time is not particularly limited, but as shown in FIG. 7, the surface of the PZT piezoelectric element 1 on the titanium material layer 4 formed on the surface of the upright plate 3 is used. Is very preferable in that the surface is flattened by cutting with a diamond tool. The cutting method using a diamond bite is used for fine processing using a precision face lathe, a precision milling machine, or the like, and can easily and surely process the surface of the PZT piezoelectric element 1 and can greatly reduce the processing time. . In addition, the use of a diamond bite enables efficient flattening of a coarse grain boundary.

Further, when the PZT piezoelectric element 1 is formed by the hydrothermal method, crystal growth by the hydrothermal method and cutting of the surface by a diamond bite are repeated until a PZT having a predetermined thickness is formed. Good. As a result, PZT having a predetermined thickness can be obtained in a flat plate shape.

[Second Embodiment] In the first embodiment, the upright portion 3 having the surface on which the piezoelectric element 1 made of PZT is formed is used.
Was repeatedly arranged in the same state. Here, the side on which the PZT piezoelectric element 1 is formed and the side on which the PZT piezoelectric element 1 is not formed are the front side and the back side, respectively, and the adjacent upright sections 3 are sequentially upright 3a and upright sections. 3b, standing plate 3
In the first embodiment, assuming that the standing plate portion 3d faces the front side of the standing plate portion 3a, the back side of the adjacent standing plate portion 3b faces the standing plate portion 3b. Part 3
The configuration was such that the back side of the c was opposed.

In the second embodiment of the ink jet head using the piezoelectric element unit according to the present invention, as shown in FIG. 8, the back sides of the adjacent standing plates 23a and 23b face each other, and the adjacent standing plates 23a and 23b face each other. The PZT piezoelectric elements 21 are arranged side by side such that the front sides of 23b and 23c face each other. The configuration of the substrate 22, the nozzle port 26, the surface electrode 29, and other components are the same as those of the inkjet head according to the first embodiment, and a detailed description thereof will be omitted.

As shown in FIG. 8, in the present embodiment, the back sides of the adjacent standing plates 23a and 23b and 23c and 23d face each other, and the front sides of the adjacent standing plates 23b and 23c face each other. And each of the PZT piezoelectric elements 2
1 are arranged side by side. In other words, a space is formed between the PZT piezoelectric elements 21 with the surfaces of the adjacent PZT piezoelectric elements 21 facing each other.

In such a juxtaposition of the PZT piezoelectric elements 21, a pair of piezoelectric elements 23b and 23c sandwiched between the substrate 22 and the top plate 27 form one air chamber 30 with a space therebetween. Will do. On the other hand, the substrate 22 and the top plate 27
Between the piezoelectric elements 23a and 23b and 2
The space between 3c and 23d is an ink pressurizing chamber 28. Therefore, the piezoelectric effect of the piezoelectric elements 23b and 23c is exerted outward from the air chamber 30, so that the piezoelectric elements 23b and 23c in the air chamber 30 are not in direct contact with the ink and the ink pressurizing chamber 28 is not in contact with the ink. Can be narrowed. Therefore, the PZT piezoelectric element 21 can be protected without forming the insulating layer 11 as in the first embodiment, and crosstalk can be prevented.

Here, in the manufacturing method of (II) in which the standing plate portion 23 is erected on the substrate 22 later, for example, as shown in FIG.
As shown in (1), it is preferable to use a support member that supports a state in which the piezoelectric elements are arranged side by side. In FIG. 9, a core (supporting member) 40 made of, for example, aluminum is provided between the back sides of the respective piezoelectric elements, and a PZT piezoelectric element 21 is arranged outside the cores 40.

In such a configuration, first, a nickel layer serving as the standing plate portion 23 is formed on the surface of an aluminum core 40 by plating or the like, a titanium material layer 24 is formed by sputtering, and PZT is formed by a hydrothermal method. Is formed, it is possible to form the PZT piezoelectric element 21 in a stable juxtaposed state. Then, a surface electrode 29 is formed on the piezoelectric element 21 made of PZT. The aluminum core 40 is easily dissolved by an alkaline solution. That is, if aluminum is exposed during hydrothermal film formation, the aluminum is dissolved in a strongly alkaline reaction solution, so that the core 40 is pretreated with nickel or titanium so that there is no exposed aluminum. Cover. The aluminum core 40 can be removed with an alkaline solution by exposing the aluminum by ion milling, mechanical polishing, or the like.
It has no effect on the piezoelectric element unit, which is the final product.

In particular, the small PZT piezoelectric elements 21 are inferior in workability and workability due to problems such as low strength and lack of handling property before being assembled together. Therefore, by using a support member such as the core 40, the problems of workability and workability are solved.
The piezoelectric element unit according to the present invention can be manufactured efficiently.

[Third Embodiment] In the first and second embodiments, the flat piezoelectric elements are arranged side by side. In the third embodiment, the piezoelectric elements are stacked on a flat unit substrate surface as in the conventional case. Do (or form to stick)
Instead, as shown in FIG. 10, a substantially cylindrical piezoelectric element 51 made of PZT is formed and arranged in parallel.

More specifically, a cylindrical (circular) piezoelectric element 51 made of PZT is formed using an aluminum core (support member) 60 in the same manner as in the second embodiment. That is, as shown in FIG. 10, a substantially cylindrical core 60 made of aluminum and having a length in the primary direction is prepared, and the diaphragm 53 corresponding to the standing plate portion 3 made of nickel or the like is provided on the surface thereof.
Is formed by plating or the like. After a titanium material layer 54 is formed at a predetermined portion of the diaphragm 53, the titanium material layer 54 is selectively formed on the titanium material layer 54 by a hydrothermal method.
The ZT piezoelectric element 51 is formed. Further, a surface electrode 59 is formed on the piezoelectric element 51 made of PZT.

Thereafter, the core 60 is removed with an alkaline solution or the like to obtain a substantially cylindrical PZT piezoelectric element 51 with electrodes, and the PZT piezoelectric elements 51 are set so that their longitudinal directions are substantially parallel to each other. A plurality of piezoelectric elements are arranged in parallel to form a piezoelectric element unit.

In this method, taking advantage of the advantage of the hydrothermal method,
Substantially cylindrical PZ that could not be manufactured by the conventional sintering method
The T piezoelectric element 51 can be easily manufactured. Moreover, since these cylindrical PZT piezoelectric elements 51 have a length in the primary direction, by disposing them so that their longitudinal directions are substantially parallel to each other, the mounting density of the PZT piezoelectric elements 51 is further improved. Can be done. Furthermore, since the PZT piezoelectric element 51 itself has a substantially cylindrical shape, when the piezoelectric element unit according to the present invention is used as an ink jet head, a piezoelectric element having high ejection efficiency and high rigidity can be obtained.

[Embodiment 4] As shown in FIG. 11, a PZT piezoelectric element 1 on a titanium material layer 4 formed on the surface of an upright portion 3 is made of a hydrothermal PZT formed by a hydrothermal method. Tier 1
a and a sol-gel method PZ formed by a sol-gel method
And a T layer 1b. By spin-coating the hydrothermal PZT layer 1a with the sol-gel PZT layer 1b,
Workability during the flattening process can be improved. That is, the sol-gel method P formed by spin coating
The unevenness remaining on the surface of the ZT layer 1b is flattened by diamond polishing or diamond cutting, but the sol-gel method PZT layer 1b requires much more machining than the hydrothermal method PZT layer 1a. Easy. Therefore, workability in flattening is greatly improved. Note that the above-described machining is unnecessary if the unevenness remaining on the surface of the sol-gel method PZT layer 1b is within a desired roughness range.

Further, after the sol-gel method PZT layer 1b is flattened, a heat treatment is performed at a high temperature in order to obtain desired characteristics with uniform crystal orientation. At this time, in order to prevent the polarization of the hydrothermally-processed PZT layer 1a from disappearing, the heat treatment is performed using PZT.
Below the Curie point, specifically 100-200 ° C
Perform within the range.

It should be noted that the sol-gel method PZ
After flattening the surface of the T layer 1b, PZT is again
By performing film formation, a multilayer piezoelectric body having a desired thickness as the PZT piezoelectric element 1 can be obtained with good workability.

[Embodiment 5] In this embodiment, after a coat layer made of an organic material or an inorganic material is formed, the coat layer is flattened. In flattening the ink pressurizing chamber 8 for the purpose of preventing air bubble trapping or the like, as shown in FIG. Coat. Alternatively, an inorganic material may be used instead of the organic material. In this case, for example, Si
Coating is performed by applying and drying an O ₂ solution. The material used for the coating is not particularly limited as long as it can coat the surface of the PZT piezoelectric element 1, but is preferably a material having good workability. By using a material with good workability, the surface of the coat layer 70 can be machined and flattened with good workability. The PZT piezoelectric element 1 formed by the hydrothermal method is formed on the titanium material layer 4 formed on the surface of the standing plate portion 3.

[Embodiment 6] In this embodiment, as shown in FIG. 13, a titanium material is used for the upright portion 3 of a unit substrate having a comb-tooth structure composed of the substrate 2 and the upright portion 3. The layer 4 is formed, and the PZT piezoelectric element 1 is formed thereon. The PZT piezoelectric element 1 is formed by coating the surface of the hydrothermal PZT layer 1a with the sol-gel PZT layer 1b by dipping. Sol-gel method PZT layer 1b coated on the surface of hydrothermal method PZT layer 1a
Has better workability when performing mechanical processing related to flattening than the hydrothermal PZT layer 1a, so that the flattening process can be performed with good workability. Then, by performing a heat treatment after the planarization treatment, the PZT crystal orientation of the sol-gel method PZT layer 1b can be made uniform.

[0109]

As described above, the piezoelectric element unit according to the present invention has a structure in which a plurality of piezoelectric elements are formed by a hydrothermal method and are arranged in parallel so that their surfaces have a substantially parallel positional relationship. It is.

Therefore, since the piezoelectric elements are arranged in parallel in a state of standing substantially upright on the flat substrate surface, the mounting density of the piezoelectric elements can be improved. Thereby, it is possible to sufficiently cover the disadvantages of the piezoelectric element formed by the hydrothermal method by improving the mounting density, and it is possible to obtain a high-performance piezoelectric element unit.

As described above, the piezoelectric element unit of the present invention has a plurality of upright portions formed substantially perpendicular to the surface of the substrate, and the piezoelectric element is formed on the surface of the upright portion. Configuration.

Therefore, it is possible to further stabilize the structure of the piezoelectric element unit having a high mounting density, and it is possible to obtain a high-performance piezoelectric element unit.

As described above, the piezoelectric element unit according to the present invention is configured such that the end of the piezoelectric element is located inside the end of the standing plate portion with a space therebetween.

Therefore, the piezoelectric element does not directly contact the substrate and the top plate forming the upper and lower surfaces of the piezoelectric element unit, and is not fixed to the substrate and the top plate. This allows
There is an effect that leakage and crosstalk between piezoelectric elements can be reduced.

As described above, the piezoelectric element unit of the present invention has a configuration in which the surface of the piezoelectric element is flattened.

Therefore, there is an effect that the piezoelectric elements can be balanced.

As described above, the piezoelectric element unit of the present invention has a configuration in which a space is formed between piezoelectric elements.

Therefore, for example, when the piezoelectric element unit according to the present invention is used for an ink jet head,
It becomes easy to protect the piezoelectric element. Thereby, there is an effect that crosstalk between the piezoelectric elements can be prevented.

As described above, in the piezoelectric element unit of the present invention, the piezoelectric element in which a plurality of piezoelectric elements are arranged is formed in a substantially cylindrical shape having a length in the primary direction by a hydrothermal method, Are arranged in parallel so that are substantially parallel to each other.

Therefore, since the surface of the piezoelectric element becomes substantially cylindrical, the mounting density of the piezoelectric element can be further improved. This produces an effect that a high-performance piezoelectric element unit can be obtained.

As described above, the ink jet head of the present invention has a configuration using the above-described piezoelectric element unit of the present invention.

Therefore, it is possible to obtain an ink jet head using a high-performance piezoelectric element unit that sufficiently covers the disadvantages of the piezoelectric element manufactured by the hydrothermal method by improving the mounting density. Thereby, there is an effect that the quality and cost of the inkjet head can be reduced.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
As described above, a titanium material layer forming step of forming a plurality of titanium material layers in a predetermined shape, and a piezoelectric element forming step of selectively forming a plurality of substantially flat piezoelectric elements on the titanium material layer by a hydrothermal method. And a piezoelectric element arranging step of arranging the plurality of piezoelectric elements in parallel so that their surfaces have a substantially parallel positional relationship.

Therefore, the piezoelectric elements can be collectively formed on the same surface of the substrate, and the mass productivity of the piezoelectric elements is improved. This produces an effect that the piezoelectric element unit can be manufactured efficiently.

The method for manufacturing the piezoelectric element unit of the present invention is as follows.
As described above, in the piezoelectric element arranging step, the supporting member is used, and after fixing each piezoelectric element in a state of facing each other, the supporting member is removed.

Therefore, it is possible to fix and handle the piezoelectric elements in a state where they face each other. This allows
There is an effect that the piezoelectric element unit can be manufactured efficiently.

The method of manufacturing the piezoelectric element unit according to the present invention comprises:
As described above, a plurality of standing plates are erected on the surface of the substrate using the diffusion bonding method and integrated.

Therefore, the rigidity of the piezoelectric element unit including the standing plate portion and the substrate can be extremely increased by diffusion bonding, and annealing (annealing) can be performed on the piezoelectric element. As a result, the performance of the piezoelectric element is improved. For example, when the piezoelectric element unit is used for an ink jet head, an effect of improving the ink ejection performance can be obtained.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
As described above, a standing plate in which a plurality of titanium material layers are formed in a predetermined shape on each standing plate surface of a unit substrate having a plurality of standing plates formed substantially perpendicular to the surface of a substantially flat substrate. The method includes a step of forming a partial surface titanium material layer and a step of forming a plurality of piezoelectric elements on the titanium material layer on the surface of the standing plate.

Therefore, the unit substrate on which the piezoelectric element is formed can be used as it is as one unit. Thereby, the step of arranging a plurality of piezoelectric elements in parallel can be omitted, and the effect of simplifying the manufacturing steps of the piezoelectric element unit can be achieved.

The method for manufacturing a piezoelectric element unit according to the present invention comprises:
As described above, a support member titanium material layer forming step of forming a titanium material layer on a substantially cylindrical support member having a length in the primary direction, and a piezoelectric element is selected on the titanium material layer by a hydrothermal method. Forming a supporting member piezoelectric element, forming the supporting member, removing the supporting member to obtain a substantially cylindrical piezoelectric element, and forming the substantially cylindrical piezoelectric element such that their longitudinal directions are substantially parallel to each other. And a step of arranging a plurality of substantially cylindrical piezoelectric elements in parallel.

Therefore, a substantially tubular PZT piezoelectric element can be easily manufactured, and the mounting density of the PZT piezoelectric element can be further improved. Accordingly, for example, when the piezoelectric element unit according to the present invention is used for an ink jet head, an effect that an ink jet head having high ejection efficiency and high rigidity can be obtained can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B show a schematic configuration of a piezoelectric element unit according to the present invention, in which FIG. 1A is a perspective view of a unit substrate, and FIG. 1B is a perspective view of the piezoelectric element unit.

FIG. 2 is a front view of the substrate showing a schematic positional relationship between the substrate and the piezoelectric element in the piezoelectric element unit according to the present invention.

FIG. 3 is a cross-sectional view illustrating a schematic configuration of a first inkjet head using a piezoelectric element unit according to the present invention.

FIG. 4 is a sectional view showing a schematic configuration of a first inkjet head using a piezoelectric element unit according to the present invention.

5A and 5B illustrate a method of manufacturing a piezoelectric element unit using a unit substrate in which a substrate and an upright portion are integrated from the beginning. FIG. 5A illustrates a titanium material layer on an upright portion. FIG. 3B is a front view of a unit substrate having a piezoelectric element formed on a titanium material layer, and FIG. 3C is a front view of a unit substrate having a piezoelectric element formed on a titanium material layer. It is a front view of a board.

FIG. 6 illustrates a method of manufacturing a piezoelectric element unit in a case where a substrate and an upright portion are separate bodies and a plurality of upright portions are erected on the substrate later. FIG. 4B is a plan view of an elastic substrate in which a shape serving as an upright portion is formed and a titanium material layer is formed in a portion where PZT is formed in the portion serving as the upright portion, and FIG. FIG. 4C is a plan view of an elastic substrate on which a titanium material layer, a piezoelectric element and a surface electrode (not shown) are formed, and a standing plate portion separated from a main frame of the elastic substrate; (D) is a front view of the substrate on which the upright portion is erected, and (e) is a front view of the substrate in which the upright portion and the substrate are integrated using the diffusion bonding method.

7A and 7B are diagrams for explaining a method of flattening the surface of a piezoelectric element formed by a hydrothermal method, and FIG. 7A illustrates a titanium material layer and a piezoelectric element formed by a hydrothermal method on the surface. It is a front view of an upright part, and (b) is a front view of the upright part in which a part of the piezoelectric element formed by the hydrothermal method was flattened by a diamond bite.

FIG. 8 is a front view showing a schematic configuration of a second inkjet head using the piezoelectric element unit according to the present invention.

FIG. 9 is a cross-sectional view of a core (supporting member) that supports a state where the piezoelectric elements are juxtaposed.

FIG. 10 is a sectional view showing a schematic configuration of a third inkjet head using the piezoelectric element unit according to the present invention.

FIG. 11 is a front view of a standing plate for explaining a method of flattening the surface of a piezoelectric element after forming a PZT layer by a sol-gel method.

FIG. 12 is a front view of an upright portion for explaining a method of flattening a coat layer after forming a coat layer of an organic material or an inorganic material.

FIG. 13 is a view showing a PZ formed by a sol-gel method on an upright portion of a unit substrate having a comb structure in which the substrate and the upright portion are integrated.
FIG. 3A is a view for explaining a method of flattening the surface of a piezoelectric element after forming a T layer, wherein FIG. 2A is a front view of a unit substrate before the surface of the piezoelectric element is flattened, and FIG. FIG. 4 is a front view of the unit substrate after the surface of the piezoelectric element has been flattened.

FIG. 14 is a front view showing a schematic positional relationship between a substrate and a piezoelectric element in a conventional piezoelectric element unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PZT piezoelectric element (piezoelectric element) 1a Hydrothermal PZT layer 1b Sol-gel method PZT layer 2 Substrate 3 Stand part 4 Titanium layer 9 Surface electrode 21 PZT piezoelectric element (piezoelectric element) 22 Substrate 23a cd standing part 24 titanium material layer 29 surface electrode 30 air chamber 40 core 51 piezoelectric element (piezoelectric element) made of PZT 53 diaphragm 54 titanium material layer 59 surface electrode 60 core 70 coat layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 41/187 H01L 41/18 101D 41/22 41/22 Z F term (Reference) 2C057 AF37 AF40 AF93 AG44 AG52 AG55 AP14 AP22 AP27 AP52 AP54 AP57 AP58 AQ06 BA02 BA03 BA14 4G031 AA11 AA12 AA32 BA10

Claims (12)

[Claims] 1. A piezoelectric element unit in which a plurality of substantially flat piezoelectric elements are arranged, wherein the plurality of piezoelectric elements are formed by a hydrothermal method so that their surfaces have a substantially parallel positional relationship. A piezoelectric element unit which is arranged in parallel. 2. The apparatus according to claim 1, further comprising a plurality of upright portions formed substantially perpendicular to the surface of the substrate, wherein the piezoelectric element is formed on the surface of the upright portion. Piezoelectric element unit. 3. The piezoelectric element unit according to claim 2, wherein an end of said piezoelectric element is formed inside and spaced apart from an end of said upright portion. 4. The piezoelectric element unit according to claim 1, wherein the surface of the piezoelectric element is flattened. 5. The piezoelectric element according to claim 2, wherein the piezoelectric element is formed on an opposing surface of the adjacent vertical plate portion, and a space is formed between the piezoelectric elements. The piezoelectric element unit according to the above. 6. A piezoelectric element unit in which a plurality of piezoelectric elements are arranged, wherein the plurality of piezoelectric elements are formed in a substantially cylindrical shape having a length in a primary direction by a hydrothermal method, and each of the plurality of piezoelectric elements has a substantially longitudinal direction. A piezoelectric element unit, which is arranged in parallel so as to be parallel. 7. An ink jet head comprising the piezoelectric element unit according to claim 1. Description: 8. On a substrate made of a material not containing titanium,
A titanium material layer forming step of forming a plurality of titanium material layers made of titanium or a material containing titanium in a predetermined shape; and forming a lead zirconate titanate (PZT) as a main component on the titanium material layer by a hydrothermal method. A piezoelectric element forming step of selectively forming a plurality of substantially plate-shaped piezoelectric elements made of a ceramic material; and a piezoelectric element arranging step of arranging the plurality of piezoelectric elements in parallel so that their surfaces have a substantially parallel positional relationship. And a method for manufacturing a piezoelectric element unit. 9. In the piezoelectric element arranging step, a supporting member for supporting each piezoelectric element in a state of facing each other is used, and after fixing each piezoelectric element in a state of facing each other, the supporting member is removed. The method for manufacturing a piezoelectric element unit according to claim 8, wherein: 10. In the piezoelectric element arranging step, after the piezoelectric elements are arranged on the surface of the standing plate portion and fixedly supported, the standing plate portion is formed on the surface of the substantially flat substrate by diffusion bonding. The method for manufacturing a piezoelectric element unit according to claim 8, wherein the piezoelectric element unit is provided and integrated. 11. A unit substrate having a plurality of upright portions formed substantially perpendicular to the surface of a substantially flat substrate and comprising titanium or titanium on a surface of each of the upright portions. A step of forming a plurality of titanium material layers made of a material in a predetermined shape on the surface of the upright plate portion, and forming a lead zirconate titanate (PZT) on the titanium material layer on the surface of the upright plate portion by hydrothermal method A vertical plate-shaped piezoelectric element forming step of selectively forming a plurality of substantially flat piezoelectric elements made of a ceramic material as a main component. 12. A support member titanium material layer forming step of forming a titanium material layer made of titanium or a titanium-containing material on a substantially cylindrical support member made of a material not containing titanium and having a length in the primary direction. A support member piezoelectric element forming step of selectively forming a substantially flat piezoelectric element made of a ceramic material containing lead zirconate titanate (PZT) as a main component on the titanium material layer by a hydrothermal method; A support member removing step of removing the support member to obtain a substantially cylindrical piezoelectric element, and a substantially cylindrical piezoelectric element arrangement in which a plurality of the substantially cylindrical piezoelectric elements are arranged in parallel so that their longitudinal directions are substantially parallel to each other. And a method for manufacturing a piezoelectric element unit.