JPH10211705A - Electromechanical transducing element, production thereof, and ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable low temp. baking by mixing a granular electromechanical transducing material preliminarily granulated so as to have a desired particle size with sol and gel-like metal alkoide. SOLUTION: An electromechanical transducing material is primarily baked to obtain single crystals of the granular electromechanical transducing material and, after the single crystals are ground, one kind of a metal alkoxide compd. is dispersed in a gelled solvent or a plurality of metal alkoxide compds. are mixed to be dispersed therein and a sol and gel mixture containing a granular piezoelectric material is dehydrated and dried and an org. binder is added to this mixture to adjust the viscosity thereof to adjust the mixture to proper viscosity. This mixture is molded into an objective shape by using a screen printing method or a green sheet method and this molded mixture is sintered at 300-900 deg.C (baked at low temp) to obtain an electromechanical transducing element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electromechanical transducer, a method for manufacturing the same, and an ink jet head.

[0002]

2. Description of the Related Art Conventionally, an electric signal is converted into a mechanical displacement,
Alternatively, an electromechanical transducer that converts mechanical displacement into an electric signal is an actuator element of an inkjet head,
Sound generators such as motors, capacitors, memories, microphones and speakers, or various sensors such as acceleration sensors, pressure sensors, vibration sensors, angular velocity sensors, and other vibration bodies,
It is used for many applications such as oscillators. In this specification, mechanical displacement is used to include displacement, stress, vibration, and the like.

[0003] An ink jet head using such an electromechanical transducer includes, for example, a plurality of ejection ports (nozzles) for ejecting ink droplets, an ink liquid chamber to which the nozzles communicate, and one wall surface of the ink liquid chamber. An electromechanical transducer such as a piezoelectric element that deforms a portion is provided, and by driving the electromechanical transducer, the volume of the ink liquid chamber is changed to eject ink droplets from a nozzle (piezo actuator type). I have.

[0004] As an ink jet recording apparatus using this ink jet head, a serial recording is carried out in which the ink jet head is mounted on a carriage and the carriage is scanned in the main scanning direction and the image receiving material is conveyed in the sub scanning direction to perform required recording. There is a scanning type recording apparatus or a line type recording apparatus using a line type inkjet head having a plurality of nozzles arranged in a row in the main scanning direction and having a length corresponding to, for example, an A4 width. This ink jet recording apparatus is widely used as various recording apparatuses such as a printer, a facsimile, a copying machine, a plotter and the like because of easy colorization.

As a conventional electromechanical transducer, a thin ceramic substrate, an electrode provided on the ceramic substrate, and a piezoelectric / electrostrictive layer are disclosed in, for example, Japanese Patent Application Laid-Open No. 5-29675. A piezoelectric / electrostrictive operating portion, wherein the piezoelectric / electrostrictive operating portion is formed by a film forming method, and the ceramic substrate is selected from the group consisting of yttrium oxide, ytterbium oxide, cerium oxide, calcium oxide and magnesium oxide. There is known a material formed of a material containing zirconium oxide as a main component, in which a crystal phase is stabilized by containing one compound.

In order to manufacture such an electromechanical transducer, a raw material such as a ferroelectric powder is weighed, mixed and dried, and then subjected to primary firing at 850 ° C. to 950 ° C., followed by pulverization. After drying and addition of a binder, mixing and cold pressing are performed to form a predetermined product shape, for example, the shape of a piezoelectric element for an ink jet head, and then the high-pressure necessary for growing the ferroelectric powder into a single crystal is obtained. By performing secondary firing at a temperature (generally 1100 ° C. to 1450 ° C.), an electromechanical transducer having a predetermined shape is obtained.

Alternatively, as described in JP-A-5-29675, a film is formed on a zirconia oxide substrate by using a paste or slurry mainly composed of ceramic particles of a piezoelectric / electrostrictive material. From 900 ° C to 1400
A method of firing at ℃ is also known. When a multi-nozzle head is obtained as an ink jet head, a piezoelectric element formed in a predetermined shape is divided by forming a slit using a dicing saw or the like.

The formation of the electromechanical transducer by firing at a high temperature as described above is disclosed in Japanese Unexamined Patent Publication No. 5-2709.
12, JP-A-7-156384, JP-A-7-156384
-1052, JP-A-6-218929, JP-A-6-206317, JP-A-6-336012
And JP-A-6-122197.

[0009]

As described above, in the conventional electromechanical transducer, the primary fired powder is heated at 850 ° C. to 1 ° C.
Baked at 000 ° C., formed into a desired shape using a binder or the like, and then subjected to secondary calcination at a high temperature of about 1300 ° C. to 1450 ° C. to grow ferroelectric material crystals. The crystal size of the material is small and the firing temperature is extremely high, resulting in an increase in cost.

In addition, since the conventional electromechanical transducer has a high firing temperature, for example, when the electromechanical transducer is integrally formed on a substrate to form an ink jet head, the substrate itself is also fired at a high temperature. Zirconia oxide or the like must be used, which can withstand the temperature, and the cost is increasing. Therefore, the cost of an inkjet recording apparatus using an inkjet head using an electromechanical transducer as an actuator element (energy generating means) is increasing. Furthermore, when manufacturing a line type ink jet head, it is difficult to obtain an ink jet recording apparatus which is low in yield, low in cost, and capable of high speed recording.

The present invention has been made in view of the above points, and has as its object to reduce the cost of an electromechanical transducer and an inkjet head using the electromechanical transducer by enabling low-temperature firing. .

[0012]

According to an aspect of the present invention, there is provided an electromechanical transducer for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal. In this device, the electromechanical conversion device was formed by mixing a granulated electromechanical conversion material, which was previously granulated to a desired particle size, into a sol-gel-like metal alkoxide and firing it.

According to a second aspect of the present invention, there is provided an electromechanical transducer for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal. The granulated electromechanical conversion material was mixed into an organometallic complex, sol-geled, and fired.

According to a third aspect of the present invention, in the electromechanical conversion element according to the first or second aspect, the granular electromechanical conversion material has a particle size of 0.1 to 20 μm.

According to a fourth aspect of the present invention, there is provided an electromechanical transducer for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal. After the granulated electromechanical conversion material was mixed and dispersed in a sol-gel-like metal alkoxide, this was fired at a temperature not exceeding 900 ° C.

According to a fifth aspect of the present invention, there is provided a method for manufacturing an electromechanical transducer for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal. After mixing the granulated electromechanical conversion material obtained by granulation into an organometallic complex, forming this into a sol-gel form and forming a thin film on the surface of the granulated electromechanical conversion material,
This was fired at a temperature not exceeding 900 ° C.

According to a sixth aspect of the present invention, in the method for manufacturing an electromechanical conversion element according to the fifth aspect, after forming a thin film on the surface of the granular electromechanical conversion material, excess sol-gel is removed. Then, this was fired at a temperature not exceeding 900 ° C.

According to a seventh aspect of the present invention, there is provided a method of manufacturing an electromechanical conversion element according to any one of the fourth to sixth aspects, wherein the granular electromechanical conversion material has a particle size of 0.1 to 20 μm. Was used.

The method of manufacturing an electromechanical transducer according to claim 8 is the method of manufacturing an electromechanical transducer according to any one of claims 4 to 7, wherein the granular electromechanical conversion material having the sol-gel at the interface is used as it is. A configuration was adopted in which a binder was added to form a pattern into a desired shape, followed by firing.

According to a ninth aspect of the present invention, there is provided an ink jet head for pressurizing ink in a pressurized liquid chamber by displacement of an electromechanical transducer to discharge ink droplets from a discharge port. The electromechanical conversion element for deforming the diaphragm portion to pressurize the pressurized liquid chamber is manufactured by the manufacturing method of claim 8.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of an electromechanical transducer to which the present invention is applied, and FIG. 2 is a schematic sectional view of a state where the electromechanical transducer is provided on a substrate.

The electromechanical transducer 1 is obtained by mixing and dispersing a granular electromechanical transducer material 2 which has been granulated to a desired particle size in a sol-gel metal alkoxide, and dispersing the sol-gel metal alkoxide into an interparticle thin film. The boundary layer 3 is formed into a predetermined shape and fired. In this case, the granulated electromechanical conversion material 2 which has been granulated to a desired particle size in advance is mixed with the organometallic complex to adjust the pH and the like to form a sol-gel.
The thin film formed on the surface may be formed into a predetermined shape as the thin film grain boundary layer 3 and then fired.

The electromechanical transducer 1 is arranged on a substrate 4 as shown in FIG. 2 and provided with electrodes 5 and 5 on both upper and lower surfaces, and contracts and shrinks by applying a voltage between the electrodes 5 and 5. An extension displacement can occur.

Here, since the electromechanical conversion element 1 has the granulated electromechanical conversion material 2 granulated in advance to a desired particle size, the temperature does not exceed 900 ° C. (hereinafter, referred to as “low temperature”).
That. ). If the effects of the present invention due to the possibility of low-temperature firing can be obtained in a smaller range, the firing can be performed at a temperature higher than the lower temperature, that is, at a temperature higher than 900 ° C., for example, about 1300 ° C. as in the conventional case.

The particle size of the granular electromechanical conversion material 2 is 0.1 μm to 20 μm for obtaining a required displacement amount, for example, when used as an actuator element of an ink jet head.
μm is preferred.

As the electromechanical conversion material for forming the granular electromechanical conversion material 2, a ferroelectric material or an antiferroelectric material can be used. PbZrO ₃ · PbTiO ₃ (lead zirconate titanate) as a ferroelectric material
(PZT) system, lead magnesium niobate (PMN) system,
Examples include materials such as lead nickel niobate (PNN), lead manganese niobate, lead antimony stannate, lead zinc niobate, and lead titanate. Examples of the antiferroelectric material include PbLaZrSnTiO ₃ (PLZST) -based and PbNbZrSnTiO ₃ (PNZST) -based materials. These antiferroelectric materials can obtain about twice the amount of displacement as compared with ferroelectric materials.

The metal alkoxide used to form the grain boundary layer 3 is Ti, Si, Al, Pb, Zr, Zn, S
One or a mixture of a plurality of alkoxide compounds such as n can be used, and a gel can be formed with pure water, hydrochloric acid, ammonia, or organic acid. The organometallic complex used to form the grain boundary layer 3 includes:
TEOS (tetraethyl orthosilicate), TMO
S (tetramethyl orthosilicate) and the like can be mentioned, and a metal alkoxide is also included.

The granular electromechanical conversion material 2 preferably has a smooth surface. In order to smooth the surface of the granular electromechanical conversion material 2, a surface modification treatment is performed. For example, a granular electromechanical conversion material of 0.5 to 20 μm is refined by a wet method (ball mill, ZrO 2). Thereby, the same series of fine particles in the amorphous state are generated. This is because alcoholic solvents and acetic acid and mineral acids (HCl,
This is because the addition of a small amount of HNO ₃ ) activates the surface of uncrystallized fine particles on the surface of the granular electromechanical conversion material or the surface of the particles pulverized by a ball mill. By gelling and amorphizing the powder, it becomes possible to form these powders, screen-print them, and fire them at a low temperature.

Since the electromechanical transducer 1 can be fired at a low temperature, the substrate 4 does not need to be a substrate that can withstand high-temperature firing such as zirconium oxide.
Glass, quartz plate, alumina, steatite and the like can also be used as the substrate. Further, when the piezoelectric element (PZT) is used as an actuator element of an ink jet head, the firing temperature is low, so that the sintering shrinkage of the piezoelectric body (PZT) is small,
Since the internal stress on the substrate is reduced, for example, 100
It is also easy to obtain a multi-element group with high positional accuracy by dividing at a density of ~ 400 dpi. Further, as a material of the electrode 5, Pt-Ru, P
While an expensive and high melting point material such as e-Pa is required, an inexpensive material such as Ag-Pd can be used.

As described above, the electromechanical conversion element is obtained by mixing the granulated electromechanical conversion material previously granulated to a desired particle size into the sol-gel-like metal alkoxide, and firing the resultant. A desired product can be obtained at a temperature (low-temperature firing), a substrate and an electrode material having low heat resistance can be used, and temperature control in a device manufacturing process can be easily performed, and the cost of the element can be reduced. However, for example, it is possible to reduce the cost of an ink jet head using this element and an ink jet recording apparatus equipped with this head, and it is possible to easily manufacture a multi-element head having a density of 50 to 400 dpi. Ink-jet heads can be manufactured easily and at low cost.

Also, the temperature does not exceed 900 ° C. by obtaining the electromechanical conversion element by mixing a granulated electromechanical conversion material previously granulated to a desired particle size into an organometallic complex, forming a sol-gel, and firing the mixture. Since a desired product can be obtained at the firing temperature (low-temperature firing), the same function and effect as described above can be obtained.

Next, a method for manufacturing an electromechanical transducer according to the present invention will be described with reference to FIGS. First, a production method using a metal alkoxide will be described.
As shown in FIG. 3, an electromechanical conversion material such as a ferroelectric material and an antiferroelectric material (here, a piezoelectric material is used).
The raw materials are weighed, mixed with a ball mill or a mortar, dried, then soft-pressed at 0.05 to 05 t / cm ² , and subjected to primary firing at 1300 to 1450 ° C. By this process, a single crystal of the granular piezoelectric material of 2 to 5 μm is obtained. This particle size depends on the degree of soft pressing before primary firing.

Then, the fired product is subjected to Et in a ball mill.
The crushed granular piezoelectric material is mixed with one or more of alkoxide compounds such as Ti, Si, Al, Pb, Zr, Zn, and Sn, and purified water, hydrochloric acid, ammonia, Disperse in a solvent gelled with an organic acid solvent.

The sol-gel mixture containing the granular piezoelectric material is dehydrated and dried (at this point, a slurry is formed), and the PV is formed.
A and starch, vinyl acetate, polyethylene glycol,
Add an organic binder such as paraffin, wax, etc., adjust the viscosity to an appropriate viscosity, and form it into the desired shape using screen printing or green sheet method.
The piezoelectric element is obtained by sintering (low temperature firing) at 900 ° C.

In this case, a heating rate of 5 ° C./min or less is preferable until dehydration during heating, desorption and decomposition of the organic material, and further dehydration, oxidation and fixation of the gel component elements start. If the rate of temperature rise is too high, the degree of occurrence of cracks increases.

Further, as shown in FIG. 4, the gelled product is dried and solidified by a vacuum dehydration method or the like, and then pulverized, and press-molded at 0.5 to 1 t / cm ² to obtain a desired shape. Molded, at a temperature not exceeding 900 ° C, preferably 300 ° C
The piezoelectric element can also be obtained by firing at a low temperature of about 800 ° C.

By sintering at such a low temperature,
Heat shrinkage, deformation and distortion due to sintering
It is smaller than 50 ° C sintering, so that a highly accurate shape can be obtained, and even when slitting with a dicing saw or the like to divide into a large number of piezoelectric elements, processing with small chipping can be performed. Become
Yield also improves.

Further, by combining the sol-gel method and the low-temperature baking, it is possible to form a large-area, long-shape pattern, etc., which has been impossible in the past. That is, conventionally, an element sintered at 1300 to 1450 ° C. is bonded and bonded to a substrate. In this case, even if a printing method is used, an expensive stabilized zirconia substrate having a sintering temperature of 1600 to 1800 ° C. must be used. Not only, but also the positional accuracy when bonding,
Even with a zirconia substrate, deformation or distortion occurs when sintering a piezoelectric material at 1300 to 1400 ° C., so that it was impossible to form a pattern having an area of 30 mm × 10 mm or more.
On the other hand, since the piezoelectric characteristics can be obtained by firing at a low temperature of 300 to 900 ° C., it is possible to form a large-area, high-precision pattern at a high density of 100 to 400 dpi.

Next, a manufacturing method using an organometallic complex will be described. As shown in FIG. 5, in the same manner as described above, a single crystal of a granular piezoelectric material having a size of 2 to 5 μm is obtained by primary firing. To TEOS (tetraethylorthosilicate), TMOS (tetramethylorthosilicate),
It is added and dispersed in a solvent containing an organometallic complex such as a metal alkoxide or a mixture thereof. As the solvent, an organic solvent having a function such as carboxylic acid, alcohol, glycol, and ketone is used.

Then, pure water or hydrochloric acid solution (0.001 to
0.1 mol%), ammonia liquid (0.01-0.1 mol%), organic acid (formic acid) (0.001-0.1 mol%), etc. Thus, a sol-gel film is uniformly formed from the organometallic complex.

Therefore, the sol-gel mixture containing the granular piezoelectric material is dehydrated and dried (at this point, a slurry is formed), and an organic binder such as PVA, starch, vinyl acetate, polyethylene glycol, paraffin, or wax is added, and the viscosity is increased. The piezoelectric element is adjusted by adjusting the viscosity to an appropriate value, forming the desired shape using screen printing or a green sheet method, and then sintering (low-temperature firing) at 300 to 900 ° C.

As described above, gelation is performed after dispersing the solvent. If the gelation rate or the porosity is small at the time of dehydration or separation of the organic material, cracks may occur. Therefore, the porosity of the metal hydroxide is improved and the shrinkage during sintering is fixed. Al-Si, Si-
It is preferable to use a mixed component such as Ti or Si-Mg-Ti.

If the metal element of the organometallic complex is excessive with respect to the weight of the piezoelectric material, hair cracks and cracks are likely to occur, and deformation and strain due to shrinkage increase.
The metal element of the organometallic complex is 8% by weight of the piezoelectric material
Is preferably within a range not exceeding.

As shown in FIG. 6, as described above, a thin film made of an organometallic complex is formed on the surface of the granular piezoelectric element by gelation by hydrolysis as described above, and then excess gel (pure water or pH adjusted solvent) is used. Organometallic complex gel) is removed by washing,
A process of leaving a thin film of the gel material only on the surface of the granular piezoelectric material can be performed. Excess gel can be removed by a precipitation method, a filtration method, a centrifugation method, or the like.

As described above, by removing the excess organometallic complex gel from the sol-gel mixture containing the granular piezoelectric material, the thin film serving as the grain boundary bonding layer becomes about 100 to 2,000 angstroms. As a result, a large displacement can be obtained with a small driving voltage when driving the piezoelectric element, deformation and distortion due to sintering are almost eliminated, and a highly accurate 100 to 400 dpi pattern can be easily obtained.

Next, the ink jet head according to the present invention will be described with reference to FIG. First, FIG. 7 is an external perspective view showing an example of an ink jet head according to the present invention, FIG. 8 is an enlarged sectional view of a main part of FIG. 7, and FIG. 9 is a perspective view of a nozzle plate of the head.

This ink jet head has one or more common ink flow paths (common liquid chambers), a liquid chamber plate 11 for forming a plurality of pressurized liquid chambers, and discharge ports (nozzles and orifices) communicating with the pressurized liquid chambers. Nozzle plate 12 that forms an ink supply path that connects the common ink flow path and the pressurized liquid chamber
And a plurality of piezoelectric elements 13 composed of electromechanical transducers provided corresponding to each pressurized liquid chamber of the liquid chamber plate 11.

The liquid chamber plate 11, as shown in FIG.
A plurality of recesses 11 a forming a plurality of pressurized liquid chambers 15, and a common ink flow path separated by the plurality of pressurized liquid chambers 15 and the partition 16 to supply ink to each pressurized liquid chamber 15. 1
7 are formed. Pressurized liquid chamber 15
The upper partition wall varies depending on the material.
A piezoelectric element 13 is provided on the outer surface of the diaphragm 18 as a deformable diaphragm 18 having a thickness of 0 μm. The common ink flow path 17 has an ink supply hole 19 through which ink from the outside flows.

On the outer surface of the liquid chamber plate 11, as shown in FIG. 7, a common electrode pattern 22 connected to one electrode 21 of all the piezoelectric elements 13 in each row is formed, and the other of the piezoelectric elements 13 is formed. And the individual electrode patterns 24 individually connected to the electrodes 23. Here, the individual electrode pattern 24 and the other electrode 23 of the piezoelectric element 13 are connected by wire bonding, conductive bonding, FPC, or the like. GND is connected to the common electrode pattern 22 connected to the piezoelectric element 13 or a voltage of several tens of volts is applied, and several tens of volts are selectively applied to the individual electrode pattern 24.
Is applied. Further, an ink supply pipe 25 for supplying ink from the outside through the ink supply hole 19 is attached to the common ink flow path 17 of the liquid chamber plate 11.

As shown in FIGS. 8 and 9, a discharge port 27 facing the pressurized liquid chamber 15 and an introduction port 27a of the discharge port 27 are formed in the nozzle plate 12, and the partition wall of the liquid chamber plate 11 is formed. An ink supply path 28 for supplying ink from the common ink flow path 17 to the pressurized liquid chamber 15 is formed corresponding to the ink path 16.

Here, the liquid chamber plate 11 including the diaphragm portion 18 is formed by firing a ceramic member formed by molding, and as described above, a desired particle size (0.1 to 20 μm) is previously formed thereon. The granulated electromechanical conversion material (granular piezoelectric material) formed by granulation is mixed and dispersed in a sol-gel-like metal alkoxide and then calcined at a low temperature, or granulated electromechanically formed in advance to a desired particle size (0.1 to 20 μm). An electromechanical transducer (piezoelectric element 13) is formed by mixing a conversion material (particulate piezoelectric material) into an organometallic complex, forming this into a sol-gel form, forming a thin film on the surface of the particulate electromechanical transducer material, and firing at a low temperature. doing.

Examples of the ceramic material used for the liquid chamber plate 11 include ceramics such as alumina, zirconia, silicon nitride, alumina nitride, and silicon carbide which have been conventionally used. Zirconia is suitable in terms of mass productivity and cost. Further, as described above, the piezoelectric element 13 of the present invention uses an electromechanical conversion element in which a metal oxide is added to a fine single crystal of a ferroelectric material which has been grown to a predetermined particle size in advance and a low temperature firing is performed. Therefore, the following ceramic materials can be used.

That is, as a glass ceramic composite material, SiO ₂ (quartz) + lead borosilicate, SiO ₂ (quartz)
+ Alumino magnesium borosilicate, forsterite + lead borosilicate, alumina + lead borosilicate, cordierite + lead borosilicate, alumina + alumino-calcium borosilicate, alumina, CaZrO ₃ + lead borosilicate, alumina + Borosilicate glass, alumina +
Glass etc. can be mentioned.

Examples of the crystallized glass-based material include cordierite / β spougemen and cordierite Z.
or the like can be mentioned _{nO · MgO · Al 2 O 3} · SiO 2. Further, as a ceramic material, BnSn (BO
₃ ) ₂ , Al ₂ O ₃ .CaO.SiO, MgO.B ₂ O ₃ , Ba
O.SiO ₂ .Al ₂ O ₃ .CaO.B ₂ O ₃ type.

These composite ceramic materials are:
The sintering temperature is as low as 700 ° C to 1000 ° C.
Compared to using ceramic materials over 0 ° C,
Cost and mass productivity are improved, and deformation and residual stress due to heat are reduced.

In particular, among the above, SiO ₂ (quartz) + lead borosilicate type, SiO ₂ (quartz) + alumino magnesium borosilicate type, cordierite / β spougemen type,
The cordierite-based _{ZnO · MgO · Al 2 O 3} · SiO 2, the thermal expansion coefficient of ^{(2~4) × 10 -6 / ℃} , so close to the value of the thermal expansion coefficient of the electromechanical transducer, firing It is more effective in reducing deformation, warpage, and residual stress.

Further, when these composite ceramic materials are used, the conductors of Ag, Au, Pt, and Cu can be simultaneously fired, and the patterning of the electrodes on the electromechanical transducer becomes easy. Among these conductors, Ag, Au,
Pt, AgPd, and PtPd have sufficient heat resistance up to 900 ° C., and can easily form a surface pattern and a multilayered inner layer pattern.

In this ink jet head, by applying a pulsed voltage to the piezoelectric element 13, the thickness direction is expanded by the unimorph structure with the diaphragm portion 18, the surface direction is contracted, and the pressure of the diaphragm portion 18 is increased. Deformation in the direction of the liquid chamber 15 occurs, and the ink in the pressurized liquid chamber 15 is pressurized in a pulsed manner to discharge ink droplets from the discharge port 27.

As described above, in this ink jet head, the diaphragm forming the wall surface of the pressurized liquid chamber is formed of the ceramic material, and the diaphragm is deformed to pressurize the pressurized liquid chamber. Since the piezoelectric element as a mechanical conversion element was formed by adding a metal oxide to a fine crystal single crystal of a ferroelectric material previously grown to a predetermined particle size and firing it, the electromechanical conversion element was formed on the diaphragm. It can be configured integrally, the configuration is simple, small,
Since the cost can be reduced and the electromechanical transducer can be fired at a low temperature, there is little deformation and residual stress after firing, and an actuator with high accuracy, high displacement efficiency and a thin diaphragm can be constructed, and high integration can be achieved. You can get a head.

Then, after firing a ceramic member formed by molding a part or the whole of the pressurized liquid chamber including the diaphragm, an electromechanical conversion element is fired thereon to form various ceramic materials. A low-cost head that can be used and has excellent mass productivity can be obtained.

In particular, the head in which the liquid chamber plate is formed using a ceramic material which can be fired at a low temperature and then fired to form electrodes and electromechanical transducers at positions corresponding to the pressurized liquid chamber, It can be fired at a lower temperature than before, making it easier to secure the accuracy of the diaphragm, improving the yield and lowering the cost, and further reducing the thickness of the diaphragm to allow for displacement. Efficiency is further improved, and high head performance is obtained.

Next, another embodiment of the ink jet head according to the present invention will be described with reference to FIG. This ink jet head is formed by firing an electromechanical transducer on a ceramic member obtained by stacking and firing at least a sheet-like ceramic material having a minimum thickness of a diaphragm portion.

That is, the liquid chamber forming member 31 corresponding to the above-described liquid chamber plate 11 has a sheet 31A made of a ceramic material having a thickness of the diaphragm portion 18 and a thickness that forms the ink supply holes 19 together with the sheet 31A. The sheet 31B and the sheets 31C and 31D forming the partition walls such as the pressurized liquid chamber 15 and the common ink flow path 17 are formed of a ceramic member which is laminated and fired, and is formed on the diaphragm 18 of the liquid chamber forming member 31. The piezoelectric element 13 as an electromechanical conversion element is formed by firing at a low temperature.

As the ceramic material used for the liquid chamber forming member 31, the ceramic material described in the above embodiment can be used. The diaphragm portion 18 has a thickness of about 5 to 20 μm although it varies depending on the size and shape, and is a very thin structure as a ceramic plate. The ejection characteristics of the head, particularly the variation of the ink droplet ejection speed and the ink droplet mass, are within a certain range. It is necessary that the accuracy of the thickness is about 0.5 to 2 μm in order to keep the thickness within this range. Can be obtained.

As described above, by firing and forming a low-temperature sinterable electromechanical conversion element on a ceramic member obtained by stacking and firing a sheet-like ceramic material having a minimum thickness of the diaphragm portion, various types of materials can be obtained. A ceramic material can be selected, a highly accurate thin plate diaphragm can be obtained, and a high displacement efficiency and a high integration head can be obtained.

In this embodiment, the sheet 31A
May be formed from a metal material, and the sheets 31B to 31D may be formed from a rigid material and joined to form a liquid chamber forming member. Here, the metal materials used are molybdenum Mo, ruthenium Ru, and high melting point metal materials.
Titanium Ti, tungsten W and the like are suitable. The joining of the metal material and the ceramic material of the laminated and fired sheets 31B to 31D can be easily performed by applying a technique to non-eutectic joining in which Au is interposed and joined. In this case, after all the sheets 31A to 31D are joined, an electromechanical transducer corresponding to the pressurized liquid chamber can be formed, or the sheet 31A can be formed after the electromechanical transducer is formed on the sheet 31A. 31B-31D can also be joined. This bonding can be performed by adhesive bonding or the like, and the pressurized liquid chamber can be easily formed.

Next, another embodiment of the ink jet head according to the present invention will be described with reference to FIGS. 11 is a sectional view of a main part of the ink jet head, FIG. 12 is a sectional view of one member constituting a liquid chamber of the head, and FIG. 13 is a sectional view of another member constituting a liquid chamber of the head. In this embodiment, at least the diaphragm portion is formed of a member that can be formed by etching, and this member is etched to form the diaphragm portion, and then the electromechanical conversion element is formed by firing, or at least the diaphragm portion is etched. After forming the electromechanical conversion element on a formable member by firing, the member is etched to form a diaphragm portion.

That is, as shown in FIG.
The member 41 made of a crystalline silicon substrate is etched using an etching solution KOH, for example, at 40% and 80 to 90 ° C. At this time, a SiO2 film is formed in advance on the upper and lower portions that are not etched, and the concave portion 41a is formed by etching using the SiO2 film as a mask, thereby forming the diaphragm portion 18. The piezoelectric element 13, the electrodes 21, 23, and the electrode patterns 22, 24 are formed on the member 41 after or before the etching in the same manner as in the above embodiment.

As the member 41, a glass member or an etchable ceramic material can be used instead of the silicon substrate. For example, SiO ₂ (quartz) + lead borosilicate, SiO ₂ + aluminum magnesium borosilicate, forsterite + lead borosilicate, and the like can be used. HF, NH ₄ F
· HF, or the like is used _{HNO 3 · H 3 PO 4 ·} HF.

Further, as the member 41, for example, 50 to 500
One having a thickness of μm can be used. By etching this member to form a diaphragm,
The thickness of the diaphragm can be formed with a high precision of 5 to 20 μm.

On the other hand, in order to obtain a common liquid chamber volume by being inserted between the member 41 and the nozzle plate, as shown in FIG. 13, similarly to the member 41, a silicon substrate, a glass member, a ceramic member or the like is used. The member 42 is etched to form a hole 42a for forming the pressurized liquid chamber 15, a hole 42b for forming the common ink flow path 17, and a groove 42c for forming the ink supply hole 19. I do.
The member 41 is not always necessary when a structure in which a common liquid chamber is separately provided outside is employed.

Then, the member 41 of FIG. 12 and the member 42 of FIG. 13 are joined as shown in FIG. 11, and the nozzle plate 12 is joined thereto. In this case, if the members 41 and 42 are both silicon substrates, they are joined using an adhesive or a dry film resist (DFR). If one is a silicon substrate and the other is a glass substrate, anodic bonding is suitable. The anodic bonding is performed by applying an electric field of 0.2 to 0.3 KV / mm between the glass surface and the silicon substrate and a 300 to 400 KV / mm.
It is joined by heat of ° C. and can be easily applied to joining members having good flatness.

As described above, the diaphragm forming the wall surface of the pressurized liquid chamber is formed by a member that can be formed by etching, and the electric machine for deforming the diaphragm and pressurizing the pressurized liquid chamber is used. The conversion element is formed by adding a metal oxide to a fine crystal single crystal of a ferroelectric material which has been grown to a predetermined particle size in advance and firing the same, thereby forming a high-precision diaphragm portion with good mass productivity. As a result, the actuator can be reduced in size and cost, and an actuator with high accuracy, high displacement efficiency and a thin diaphragm can be formed, and a highly integrated head can be obtained.

Next, still another embodiment of the ink jet head according to the present invention will be described with reference to FIGS. 14 is a cross-sectional view of the head, FIG. 15 is a cross-sectional view of one member constituting the liquid chamber of the head, FIG. 16 is a plan view of the member of FIG. 15, and FIG. 18 is a cross-sectional view taken along line CC of FIG.

Also in this embodiment, at least the diaphragm portion is constituted by a member which can be formed by etching, the member is etched to form the diaphragm portion, and then the electromechanical conversion element is formed by firing, or at least the diaphragm portion is formed. Is formed by firing an electromechanical conversion element on a member that can be formed by etching, and then the diaphragm is formed by etching the same member.

In this ink jet head, a member 51 in which the piezoelectric element 13 is formed on the diaphragm 18 and an ink flow path forming member 52 are joined to serve as the pressurized liquid chamber 15, the common ink flow path 17, and the fluid resistance section. This is an edge shooter type head which forms an ink supply path 28 and a discharge port 27 and discharges ink droplets from an end face of a member 52.

That is, as shown in FIGS. 15 and 16, the diaphragm portion 18 is formed by etching the member 51 made of a silicon substrate, a glass substrate, an etchable ceramic material or the like to form a concave portion 51a. After etching or before etching, this member 51
The piezoelectric element 13, the electrodes 21 and 23, and the electrode patterns 22 and 24 are formed on the member 51 in the same manner as in the above embodiment.

On the other hand, as shown in FIG. 17 and FIG.
11) A member 52 made of a crystalline silicon substrate is etched to form a concave portion 52a serving as a pressurized liquid chamber 17, a concave portion 52b serving as a common ink channel 17, a groove portion 52c serving as an ink supply passage 28, and a discharge port 27. The grooves 52d are respectively formed. In this case, when the depth of the common liquid chamber (concave section 52b) is 100 μm and the depth of the pressurized liquid chamber section (concave section 52a) is about 50 μm, the etching mask and the etching step are performed in two steps. become.

The member 51 thus formed is
The inkjet head is formed by joining the and the member 52. Even with such a configuration, the same operation and effect as those of the above embodiment can be obtained.

Next, an example of a serial scan type ink jet recording apparatus provided with an ink jet head according to the present invention will be described with reference to FIGS. FIG. 19 is a schematic plan view of the ink jet recording apparatus, and FIG. 20 is a schematic side view of the recording apparatus.

This ink jet recording apparatus includes a front guide 62 provided between left and right main scanning frames 61,61.
The carriage 4 is slidably mounted on the guide shaft 63, a recording head 65 comprising an ink jet head according to the present invention is mounted on the lower surface of the carriage 64, and an ink cartridge 66 is detachably provided on the upper surface. The recording head 65 has a plurality of inkjet heads that respectively eject ink for yellow (Y), magenta (M), cyan (C), and black (Kb) arranged in the main scanning direction.

Then, the left and right main scanning frames 61, 61
A main scanning drive motor 6 is mounted on a substantially L-shaped stay 67 provided therebetween.
8, a belt 71 is stretched between a motor pulley 69 attached to the rotation shaft of the main scanning drive motor 68 and a side pulley 70 attached to the stay 7, and the carriage 64 is attached to the carriage 71 as shown in FIG. The main scanning drive motor 68 is rotationally driven by being fixed to the belt 71 by a belt clamp 72, so that the carriage 64 scans in the direction indicated by the arrow D in FIG. 19 (main scanning direction). The side pulley 70 is attached so as to be able to move slightly in the main scanning direction, and tension is applied to the belt 71 by a tension spring 73.

On the other hand, a platen 76 is rotatably mounted between the left and right sub-scanning frames 75, 75, and the transport rollers 7 pressed against the peripheral surface of the platen 76 as shown in FIG.
7 and 78, and a paper pan 79 for guiding the paper along the peripheral surface of the platen 76. Then, a paper feed tray 81 set on the lower front side of the recording apparatus
The sheet 84 as the recording medium loaded on the ascending tray 83 urged by the ascending spring 82 is fed out one by one by the sheet feeding roller 85 and the corner claw 86 of the sheet feeding tray 81, and is fed along the sheet feeding guide 87. The guide is guided to the peripheral surface of the platen 86.

A paper guide 88 serving as a paper guide is disposed near the paper exit of the platen 76 so as to face the carriage 4, and the paper 84 sent out from the platen 76 is pressed near the entrance of the paper guide 88. A paper press 89 is provided, and a paper discharge roller 91 and a spur roller 9 for discharging paper 84 to a paper discharge tray 90 are provided near the exit.
2 are arranged.

Further, as shown in FIG. 19, a sub-scanning drive motor 94 is mounted on a sub-frame 93 mounted on the main scanning frame 61, a motor gear 95 is mounted on the rotation shaft of the sub-scanning drive motor 94, and an idler gear is mounted on the motor gear 95. 96, and an idler gear 97 integrated with the idler gear 96 is engaged with a platen gear 98 attached to an end of the platen 76, and a sub-scanning drive motor 94
Is transmitted to the platen 76 and also to various rollers and rollers, and by rotating the sub-scanning drive motor 94, the platen 76 and the various rollers and rollers rotate to move the paper 84 on the paper guide 88 on the paper guide 88. The sheet is conveyed in the direction E (sub-scanning direction).

With such a configuration, the recording head 65
While moving the (carriage 64) in the main scanning direction, the paper 84 is transported in the sub-scanning direction, and the recording head 65 is moved.
A required image is recorded on the paper 84 by ejecting ink droplets from the nozzles.

As described above, the provision of the ink jet head according to the present invention makes it possible to obtain an ink jet recording apparatus capable of high-density, high-speed recording. Further, since the electromechanical transducer used in the present invention can be fired at a low temperature, it can be easily applied to a line type ink jet head in which nozzles are arranged in a line, and a high integration density ink jet head can be manufactured at low cost. It is possible to obtain a low-cost line-type inkjet recording apparatus that can be manufactured and that can perform high-density and high-speed recording.

Note that the electromechanical transducer according to the present invention comprises:
Not only can it be used as the actuator element of the ink jet head described in the above embodiments, but also other, a motor, a capacitor, a memory, a microphone, a sounding body such as a speaker, or an acceleration sensor, a pressure sensor,
It can be used for various applications such as various sensors such as a vibration sensor and an angular velocity sensor, as well as a vibrating body and an oscillating body. Further, the configurations of the above-described inkjet head and inkjet recording apparatus are not limited to those of the above-described embodiment.

[0089]

As described above, according to the electromechanical transducer of the first aspect, the electromechanical transducer is a sol-gel-like metal alkoxide formed of a granular electromechanical transducer formed in advance to a desired particle size. In this case, a desired element can be obtained at a firing temperature (low temperature firing) not exceeding 900 ° C., an element with less distortion can be obtained, and a substrate or electrode material having low heat resistance can be obtained. Not only can the device be used at low cost, but also the cost of, for example, an ink jet head using the device and an ink jet recording apparatus equipped with the head can be reduced.
A multi-element head having a density of about 400 dpi can be easily manufactured, and in particular, a line type ink jet head can be easily manufactured at low cost.

According to the electromechanical transducer of the second aspect, the electromechanical transducer is prepared by mixing a granulated electromechanical transducer material, which has been granulated to a desired particle size, into an organometallic complex and firing it into a sol-gel form. Therefore, a desired element can be obtained at a firing temperature (low-temperature firing) not exceeding 900 ° C., an element with less distortion can be obtained, and a substrate or an electrode material having low heat resistance can be used. In addition to lowering the cost, it is possible to reduce the cost of, for example, an ink jet head using this element or an ink jet recording apparatus equipped with this head, and to easily manufacture a multi-element head having a density of 50 to 400 dpi. In particular, it is possible to easily and inexpensively manufacture a line type ink jet head.

According to the electromechanical transducer of the third aspect, since the electromechanical transducer of the first or second aspect is configured such that the particle size of the granular electromechanical transducer is 0.1 to 20 μm, A large amount of elements can be obtained.

According to the method of manufacturing an electromechanical transducer of claim 4, a particulate electromechanical transducer material granulated in advance to a desired particle size is mixed and dispersed in a sol-gel-like metal alkoxide and then heated to 900 ° C. Since the baking is performed at a temperature not exceeding, a device with less distortion can be obtained, a substrate and an electrode material having low heat resistance can be used, and not only can the cost of the device be reduced, but also, for example, the use of this device can be reduced. The cost of the ink jet head and the ink jet recording apparatus equipped with this head can be reduced, and a multi-element head having a density of 50 to 400 dpi can be easily manufactured. Moreover, it can be performed at low cost.

According to the method of manufacturing an electromechanical conversion element of the present invention, the electromechanical conversion material granulated in advance to a desired particle size is mixed into an organometallic complex, and the mixture is formed into a sol-gel form to form the electromechanical conversion element. Since a thin film is formed on the surface of the mechanical conversion material and then fired at a temperature not exceeding 900 ° C., a gel film is uniformly formed on the grain boundaries of the crystalline electromechanical conversion material, and the low temperature firing is performed. The bonding force of the element is improved, an element having a high degree of sintering and less distortion can be obtained, and a substrate or an electrode material having a low heat resistance can be used. This not only reduces the cost of the element but also reduces the cost of the element. The cost of the ink jet head used and the ink jet recording apparatus equipped with this head can be reduced, and a multi-element head having a density of 50 to 400 dpi can be easily manufactured. The fabrication of the head will be able to be performed in easily and cost.

According to the method of manufacturing an electromechanical transducer of claim 6, in the method of manufacturing an electromechanical transducer of claim 5, after forming a thin film on the surface of the granular electromechanical conversion material, excess sol-gel is removed. Removed and then brought to 900 ° C
, So that a grain boundary layer of 100 to 2,000 angstroms can be formed on the surface of the granular electromechanical transducer, so that shrinkage deformation and distortion can be further reduced, and drive displacement can be reduced. It is possible to obtain a large amount of an element which can be driven at a low voltage.

According to the method of manufacturing an electromechanical transducer of claim 7, in the method of manufacturing an electromechanical transducer of any one of claims 4 to 6, the particle size of the granular electromechanical conversion material is 0.1. Since a structure having a thickness of about 20 μm is used, an element having a large displacement can be obtained.

According to the method of manufacturing an electromechanical transducer of claim 8, in the method of manufacturing an electromechanical transducer of any of claims 4 to 7, the granular electromechanical conversion material having the sol-gel at an interface is used. Since the composition is fired after being patterned into a desired shape as it is or by adding a binder, an element array group having a large area and a high precision pattern can be easily formed.

According to the ink jet head of the ninth aspect, in the ink jet head in which the ink in the pressurized liquid chamber is pressurized by the displacement of the electromechanical transducer to discharge the ink droplet from the discharge port, the wall surface of the pressurized liquid chamber is Since the electromechanical conversion element for deforming the formed diaphragm and pressurizing the pressurized liquid chamber is manufactured by the manufacturing method according to claim 8, the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electromechanical transducer according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a state where the electromechanical transducer is arranged on a substrate.

FIG. 3 is a flowchart showing an example of a method for manufacturing an electromechanical transducer using a metal alkoxide according to the present invention.

FIG. 4 is a flowchart showing another example of a method for manufacturing an electromechanical transducer using the same metal alkoxide.

FIG. 5 is a flowchart showing an example of a method for manufacturing an electromechanical transducer using the organometallic complex according to the present invention.

FIG. 6 is a flowchart showing another example of a method for manufacturing an electromechanical transducer using the same metal alkoxide.

FIG. 7 is an external perspective view showing an example of an inkjet head according to the present invention.

FIG. 8 is an enlarged sectional view of a main part of FIG. 7;

FIG. 9 is a perspective view of the nozzle plate of FIG. 8;

FIG. 10 is an enlarged sectional view of a main part showing another embodiment of the ink jet head according to the present invention.

FIG. 11 is an enlarged sectional view of a main part showing still another embodiment of the ink jet head according to the present invention.

FIG. 12 is a sectional view of one member constituting a liquid chamber of the head.

FIG. 13 is a sectional view of the other member constituting the liquid chamber of the head.

FIG. 14 is an enlarged sectional view of a main part showing still another embodiment of the ink jet head according to the present invention.

FIG. 15 is a sectional view of one member constituting a liquid chamber of the head.

FIG. 16 is a plan view of FIG.

FIG. 17 is a sectional view of the other member constituting the liquid chamber of the head.

18 is a sectional view taken along the line CC of FIG.

FIG. 19 is a plan view showing an example of an ink jet recording apparatus according to the present invention.

FIG. 20 is a side view of a main part of the recording apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electromechanical conversion element, 2 ... Granular electromechanical conversion material, 3
... grain boundary layer, 11 ... liquid chamber plate, 12 ... nozzle plate, 13 ... piezoelectric element, 15 ... pressurized liquid chamber, 17 ... common liquid chamber, 18 ... diaphragm part, 27 ... discharge port.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 41/26

Claims (9)

[Claims] 1. An electromechanical transducer for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal, wherein the electromechanical transducer is a granular electromechanical device which is granulated in advance to a desired particle size. An electromechanical conversion element characterized in that a conversion material is mixed with a sol-gel metal alkoxide and fired. 2. An electromechanical conversion element for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal. An electromechanical conversion element, wherein a conversion material is mixed with an organometallic complex to form a sol-gel and fired. 3. The electromechanical conversion element according to claim 1, wherein the particle size of the granular electromechanical conversion material is 0.1.
An electromechanical transducer having a thickness of from about 20 μm to about 20 μm. 4. A method of manufacturing an electromechanical conversion element for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal, comprising the steps of: A method for producing an electromechanical conversion element, comprising mixing and dispersing a metal alkoxide in a sol-gel state, followed by firing at a temperature not exceeding 900 ° C. 5. A method for manufacturing an electromechanical conversion element for converting an electric signal into a mechanical displacement or converting a mechanical displacement into an electric signal, comprising the steps of: Manufacturing an electromechanical conversion element, which is mixed with an organometallic complex, converted into a sol-gel form, forms a thin film on the surface of the granular electromechanical conversion material, and is fired at a temperature not exceeding 900 ° C. Method. 6. A method for manufacturing an electromechanical transducer according to claim 5, wherein after forming a thin film on the surface of the granular electromechanical transducer material, excess sol-gel is removed, and then a temperature not exceeding 900 ° C. A method for manufacturing an electromechanical transducer, wherein the method is performed by firing. 7. The method for manufacturing an electromechanical conversion element according to claim 4, wherein said granular electromechanical conversion material has a particle size of 0.1 to 20 μm. A method for manufacturing a mechanical conversion element. 8. The method for manufacturing an electromechanical conversion element according to claim 4, wherein the granular electromechanical conversion material having the sol-gel at the interface is used as it is or by adding a binder to a desired shape. A method for producing an electromechanical conversion element, comprising firing after patterning. 9. In an ink jet head that pressurizes ink in a pressurized liquid chamber by displacement of an electromechanical transducer and discharges ink droplets from a discharge port, a diaphragm portion forming a wall surface of the pressurized liquid chamber is deformed. 10. An ink jet head, wherein the electromechanical transducer for pressurizing the pressurized liquid chamber is manufactured by the manufacturing method according to claim 9.