JPH11348285A - Ink jet recorder and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head having ejection nozzles which are formed in high density by a method wherein a piezoelectric material and a vibration plate forming a piezoelectric device is made to be a thin film so that fine processing which is regularly used in a semiconductor process can be used. SOLUTION: The ink jet recorder comprises an ink ejection nozzle, a pressure generating chamber 1 connected to an ink ejection nozzle 2 and a piezoelectric vibration section which consists of a piezoelectric membrane 5 having Pb, Ti and Zr and electrodes 6, 7 provided to both sides of the piezoelectric membrane 5 and is provided to a part of the pressure generating chamber 1. The piezoelectric membrane 5 consists of a first layer 8 and a second layer 9 each having a perovskite structure both of which are contacted with each other. The first layer 8 does not include Zr or the content of the Zr in the first layer 8 is less than that in the second layer 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head recording apparatus used in an ink jet recording apparatus and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, printers using an ink jet recording apparatus as a printing apparatus such as a personal computer have been widely used because of their good printing performance, easy handling and low cost. This ink jet recording apparatus includes a device that generates bubbles in ink by thermal energy and discharges ink droplets by pressure waves generated by the bubbles, a device that suctions and discharges ink droplets by electrostatic force, and a vibrator such as a piezoelectric element. There are various systems such as those using pressure waves.

In general, a device using a piezoelectric element includes, for example, a pressure chamber communicating with an ink supply chamber and an ink discharge port communicating with the pressure chamber, and a diaphragm having a piezoelectric element joined to the pressure chamber. It is provided and configured. In such a configuration, a predetermined voltage is applied to the piezoelectric element to expand and contract the piezoelectric element, thereby causing flexural vibration and compressing the ink in the pressure chamber, thereby discharging ink droplets from the ink discharge ports. At present, color ink jet recording apparatuses have become widespread, but there is a demand for improved printing performance, particularly for higher resolution and higher speed printing. Therefore, it has been attempted to realize high resolution and high speed printing using a multi-nozzle head structure in which an ink head is miniaturized. In order to miniaturize the ink head, it is necessary to reduce the size of a piezoelectric element for discharging ink.

[0004]

However, the method of forming the piezoelectric film of the piezoelectric element by forming a powder of PbO, ZrO2 and TiO2 into a sheet and then firing the sheet is adopted. For example, if the piezoelectric film
It was difficult to form a thin film having a thickness of 0 μm or less. For this reason, it was difficult to finely process the piezoelectric film, and it was difficult to reduce the size of the piezoelectric element. Further, as the thickness of the piezoelectric film formed by sintering the powder becomes thinner, the influence of the crystal grain boundaries cannot be ignored, and good piezoelectric characteristics cannot be obtained. As a result, the piezoelectric film formed by baking the powder has a problem that when the thickness is 15 μm or less, it is not possible to obtain sufficient piezoelectric characteristics for discharging ink. For this reason, it has not been possible to realize a small-sized ink head having characteristics necessary for sufficient ink ejection.

According to the present invention, a thin film material having a large piezoelectric property even if the film thickness is small is developed, and a piezoelectric material or a diaphragm constituting a piezoelectric element is thinned to obtain a thin film material generally used in a semiconductor process. It is an object of the present invention to provide a configuration capable of processing and realizing an inkjet head having discharge ports formed at high density, and a method of manufacturing the same.

[0006]

According to a first aspect of the present invention, there is provided a first ink jet head having a main body having an ink discharge port and a pressure chamber connected to the ink discharge port, and a piezoelectric film having Pb, Ti and Zr. And an electrode provided on both sides of the piezoelectric film, comprising: a piezoelectric vibrating portion provided in a part of the pressure chamber, wherein the piezoelectric vibrating portion bends and vibrates to discharge ink from an ink discharge port. Wherein the piezoelectric film includes a first layer having a perovskite structure containing Sr or Ba, and a second layer having a perovskite structure having Pb, Ti, and Zr formed so as to be in contact with the first layer. It is characterized by the following.

Thus, the first layer having a perovskite structure containing Sr or Ba and the second layer in contact with the first layer are provided.
By including the layer, the second layer containing Zr can be formed so as to be high quality, thin, and have a large piezoelectric constant. Thereby, the first inkjet head of the present invention can be made extremely small and lightweight.

A second ink jet head according to the present invention comprises a main body having an ink discharge port and a pressure chamber connected to the ink discharge port, a piezoelectric film having Pb, Ti and Zr, and a piezoelectric film having Pb, Ti and Zr. An ink jet head that includes an electrode provided on both sides and includes a piezoelectric vibrating part provided in a part of the pressure chamber, and discharges ink from an ink discharge port by bending and vibrating the piezoelectric vibrating part, The piezoelectric film includes a first layer and a second layer each having a perovskite structure and formed so as to be in contact with each other, and the Zr content of the first layer is compared with the Zr content of the second layer. It is characterized by being small.

As described above, by configuring the piezoelectric film to include the first layer and the second layer formed so as to be in contact with each other, the second layer containing a relatively large amount of Zr can be made of a high quality, thin, and thin. It can be formed to have a large piezoelectric constant. Thereby, the second inkjet head of the present invention can be made extremely small and lightweight.

A third ink jet head according to the present invention comprises a main body having an ink discharge port and a pressure chamber connected to the ink discharge port, a piezoelectric film having Pb, Ti and Zr, and a piezoelectric film having a piezoelectric film having Pb, Ti and Zr. An ink jet head that includes an electrode provided on both sides and includes a piezoelectric vibrating part provided in a part of the pressure chamber, and discharges ink from an ink discharge port by bending and vibrating the piezoelectric vibrating part, A first layer having a perovskite structure and having no Zr formed so as to be in contact with each other;
and a second layer having r.

As a result, a second layer having higher quality and a higher piezoelectric constant can be formed as compared with the second ink jet head.

In the second and third ink jet heads according to the present invention, it is preferable that the first layer contains La in order to easily form the first layer at a low temperature.

Further, in the first to third ink jet heads according to the present invention, in order to further increase the piezoelectric constant of the piezoelectric film, the Zr / Ti ratio in the second layer is 30/70.
It is preferable to set it to 70/30 or less.

In the first to third ink jet heads according to the present invention, it is more preferable that the piezoelectric film is a single crystal. Thereby, the inherent piezoelectric constant of the material constituting the piezoelectric film can be effectively used.

In the first to third ink jet heads according to the present invention, the piezoelectric film is preferably formed to a thickness of 10 μm or less, whereby the shape of the piezoelectric film can be finely processed.

In the first to third ink jet heads according to the present invention, the piezoelectric film has a thickness of 1 μm or more and 3 μm or more.
It is more preferable that the piezoelectric film is formed to have the following thickness, whereby the piezoelectric film can be finely processed, and a sufficient ink ejection force and a sufficient reliability of the piezoelectric film can be obtained.
In this case, the first layer is preferably formed to have a thickness of 50 nm or more and 100 nm or less.
A high-quality second layer can be formed, and the piezoelectric constant of the entire piezoelectric film does not decrease.

Further, in the first to third ink jet heads according to the present invention, since the piezoelectric vibrating section includes the vibration plate, the piezoelectric vibrating section can easily bend and vibrate. In this case, it is preferable that the diaphragm is made of at least one material selected from the group consisting of Ni, Cr, Al and oxides thereof, Si, Si oxide, and a high molecular organic substance.

Further, in the first to third ink jet heads according to the present invention, in the piezoelectric vibrating portion, a piezoelectric film different from the piezoelectric film and facing the piezoelectric film via the intermediate electrode layer between the electrodes. May be provided, and the two piezoelectric films may cause flexural vibration. If the two piezoelectric films are flexibly vibrated in this manner, a larger amplitude can be obtained as compared with the case where a diaphragm is used.

Further, in the first and third ink jet heads according to the present invention, the second layer of the piezoelectric film may be an antiferroelectric piezoelectric material containing Nb and Sn.

Further, in the first to third ink jet heads according to the present invention, the first layer is a layer in which the Zr concentration is distributed so as to increase continuously in the thickness direction, and May be configured to be in contact with the second layer on one surface having a high Zr concentration.

In the first to third ink jet heads according to the present invention, it is preferable that the electrode layers formed on both sides of the piezoelectric film are formed of Pt or Au.
Thus, when the piezoelectric film is finely processed by, for example, etching, the electrodes can be prevented from being damaged by the etchant.

In the first to third ink-jet heads according to the present invention, the main body has a plurality of ink discharge ports and a plurality of pressure chambers provided respectively corresponding to the respective ink discharge ports. By separately providing at least one of the electrodes provided on both sides of the film so as to correspond to the pressure chamber, it is possible to configure an ink jet head having a piezoelectric vibrating portion corresponding to each pressure chamber. With such a configuration, an ink jet head in which a plurality of ink ejection ports are formed at a very high density can be manufactured. In this case, even if the piezoelectric film is separately provided so as to correspond to the pressure chamber, and one electrode is formed on each of the separated piezoelectric films, the ink jet head similarly having the ejection ports formed at a high density Can be produced. As described above, when the piezoelectric films are formed separately so as to correspond to the respective pressure chambers, it is preferable that the width of each piezoelectric film is smaller than the width of the pressure chamber. In the case where the piezoelectric films are formed separately, a resin having low rigidity that does not hinder expansion and contraction of the piezoelectric films may be filled between the separated piezoelectric films.
Thereby, the reliability of the head can be increased.

Further, in the first to third ink jet heads according to the present invention, the piezoelectric vibrating portion has a peripheral portion which is elastic with the peripheral portion of the pressure chamber via a resin layer having a thickness of 3 μm or less. May be joined together,
It is possible to prevent distortion from being applied to the piezoelectric vibrating portion during bonding, and to increase the production yield and reliability.

Preferably, the peripheral portion of the piezoelectric vibrating portion is joined to the peripheral portion of the pressure chamber via a pedestal made of ceramic, metal, or resin, so that the joining portion is separated from the piezoelectric vibrating portion. Therefore, the piezoelectric vibrating portion can be vibrated stably.

Further, the method of manufacturing an ink jet head according to the present invention is characterized in that a main body having an ink discharge port and a pressure chamber connected to the ink discharge port and having an opening formed in a part thereof is formed, and the opening is closed. And a piezoelectric vibrating section provided on the substrate, wherein a first layer having a perovskite structure containing Pb and Ti is formed on a substrate, and Zr, Pb and Ti are formed on the first layer. Forming a piezoelectric layer including a first layer and a second layer by forming a second layer having a perovskite structure including: a piezoelectric vibrating section having a piezoelectric film on a substrate. A first step of bonding the peripheral portion of the opening of the main body to the peripheral portion of the piezoelectric vibrating portion, and a third step of removing the substrate after the bonding. , The first layer does not contain Zr. Z As or compared to the second layer
It is characterized in that it is formed so as to reduce the amount of r.

According to the present manufacturing method, the second layer containing a relatively large amount of Zr can be formed to have good quality, be thin, and have a large piezoelectric constant. Thus, according to the manufacturing method of the present invention, an extremely small and lightweight inkjet head can be manufactured.

In the manufacturing method according to the present invention, it is preferable to form the first layer and the second layer by a sputtering method or a CVD method in order to form the layers accurately and with good quality.

In the manufacturing method according to the present invention, M
By using the gO substrate, the first layer of the single crystal and the second layer
Layers can be formed. In this case, in the third step, the substrate can be removed by etching using phosphoric acid.

In the manufacturing method according to the present invention, a silicon substrate or a glass substrate can be used as the substrate, and thus, it can be manufactured at a lower cost than when an MgO substrate is used. In this case, in the third step, the substrate can be removed by etching using a hydrofluoric acid-based solution or a potassium hydroxide solution.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) An ink jet head 100 according to Embodiment 1 of the present invention has a thin and large piezoelectric constant formed by using a so-called thin film forming method such as sputtering, which has been conventionally difficult. It is constituted by using a piezoelectric film, and is characterized in that it is extremely small in size and can be formed with a narrow interval between ink discharge ports as compared with the conventional ink jet head.

FIG. 1A is a perspective view of an ink jet head 100 according to the first embodiment of the present invention.
FIG. 2B is a cross-sectional view taken along line AA ′ of FIG.

This ink jet head 100 has the structure shown in FIG.
(A) As shown in (b), a plurality of discharge ports 2, pressure chambers 1 provided for each of the discharge ports 2, and a piezoelectric element 3 provided in each of the pressure chambers 1 are provided. It is configured as follows.

In the ink jet head 100, the discharge ports 2 are formed at predetermined intervals on the side surface of the main body 50, and the pressure chambers 1 are formed so as to correspond to the discharge ports 2, respectively.
0. The pressure chamber 1 corresponding to each ejection port 2 is provided with an ink flow path 2 formed in the main body 50.
a. Openings 51 are formed on the upper surface of the main body 50 so as to correspond to the respective pressure chambers 1.
Further, a diaphragm 4 is formed on the upper surface of the main body 50 so as to cover the opening 51, and the piezoelectric element 3 is located on the diaphragm 4 so as to be located on each opening 51 corresponding to each pressure chamber 1. Provided.

The piezoelectric element 3 is, as shown in FIG.
Electrodes 6 of platinum each having a thickness of 0.1 μm
And 7 and a piezoelectric film 5 having a thickness of 3 μm formed between the electrodes 6 and 7, and is provided on the diaphragm 4. Here, the diaphragm 4 is formed of a SiO ₂ layer having a thickness of 2 μm at a vibrating portion. As described above, the piezoelectric vibrating portion 30 is formed by the piezoelectric element 3 and the piezoelectric plate 4.

By using a perovskite-type PZT thin film material, which is an oxide composed of lead, titanium and zirconium, as the material of the piezoelectric film 5, good vibration can be achieved even at a low voltage. In this specification, the term “PZT” refers to a piezoelectric material represented by the general formula Pb (Zr _x Ti _1-x ) O ₃ containing Pb, Zr and Ti. The composition of this PZT thin film is Pb (Zr
It has been revealed that the sintered body exhibits the maximum piezoelectricity in the case of _0.53 Ti _0.47 ) O ₃ . However, it is not easy to form a thin film of this composition directly on the electrode.

Accordingly, in the first embodiment, as shown in FIG. 3, the piezoelectric film 5 is composed of two layers, and the first layer 8 is PtTiO ₃ containing no Zr or PLT in which lanthanum is added to PbTiO _3. Is formed, and Pb (Zr
By forming a layer having a composition of _0.53 Ti _0.47 ) O3,
A high quality piezoelectric thin film (piezoelectric film 5) having good piezoelectric characteristics was formed. That is, the present invention forms PbTiO ₃ containing no Zr or PLT in which lanthanum is added to PbTiO ₃ as a first layer, and forms Pb (Zr _0.53
The present invention was completed by finding that a high-quality piezoelectric thin film having good piezoelectric characteristics can be formed by forming a layer having a composition of Ti _0.47 ) O ₃ .

Hereinafter, the piezoelectric film 5 having two layers will be described.
This will be described in detail. As mentioned above, PZT has good pressure
With electrical characteristics and Zr / Ti ratio of about 50/50
Is known to have a very high piezoelectric coefficient
You. However, PZT is not suitable for sputtering or CVD.
It is difficult to form a good film using the thin film forming method.
That is, as the ratio of Zr to Ti increases, the tendency becomes
Notable. According to our study, the cause is thin film type
During the formation process, the oxide of Zr is adsorbed on the substrate surface,
It is clear that this is to inhibit the film growth after
Was. The tendency is that a PZT film is grown on a Pt electrode.
It is clear that it is even more pronounced when trying to
Was. However, PbTiO_ThreeOr PbTiO_ThreeTo L
a was added to about 10 mol% to lower the crystallization temperature.
(Pb, La) TiO_Three(Hereinafter simply referred to as PLT)
When PZT is grown using a thin film forming method,
Creates a good PZT film without depositing r-oxide
can do. Also, PbTiO_ThreeAnd PLT
A thin film forming method having a perovskite structure similar to PZT
Can be formed relatively easily also on the Pt electrode using
It is a film that can be cut. For this first layer, the basic conditions
Must have a perovskite-type structure.
bTiO_ThreeSrTiO besides PLT_Three, BaTiO _Three
According to our studies, SrRuO3 and others are also effective.
Has been proven. This first layer has the same R as that of PZT.
It can be formed using F sputtering equipment,
By using a sputtering device that can attach
The formation of layer 8 and second layer 9 can proceed in a series of steps.
You.

In the present invention, instead of such a multilayer structure, Zn-free PbTiO _{3 is} converted to Pb (Zr _0.5 Ti
_0.5 ) The same effect can be obtained by using the piezoelectric film 5 using the first layer having a composition gradient continuously changed to a composition near O ₃ .

Hereinafter, a method of manufacturing the ink jet head according to the first embodiment will be described with reference to FIG.

In this manufacturing method, first, a 2 cm square (10
On the upper surface of the single-crystal MgO substrate 10 having the 0) plane as the upper surface, a single-crystal Pt electrode film is oriented and formed to a thickness of 0.1 μm (step S1 in FIG. 5A).

Next, the Pt electrode film is patterned into individual electrodes 11 by dry etching (using Ar ions in a vacuum) so as to correspond to each pressure chamber (step of FIG. 5A). S2 and FIG. 4).

Next, an initial layer made of PbTiO ₃ (first layer)
Layer) is formed to a thickness of about 0.01 μm (Step S3 in FIG. 5A).

Then, a PZT thin film is formed on the initial layer to a thickness of about 3 μm by sputtering (step S4 in FIG. 5A).

In steps S3 and S4, the substrate is grown at a temperature of 500 to 600 ° C. to grow a film.

As described above, in the present manufacturing method, PZ
Before forming the T thin film, PbTiO _ThreeThe initial layer consisting of
As it is formed, it is excellent in crystallinity with less deviation of composition
Forming a single-crystal PZT thin film oriented along the c-axis;
Can be. PZT is the highest piezoelectric coefficient in the c-axis direction.
Having.

Next, the PZT thin film (including the initial layer) is patterned by etching using a strongly acidic solution.
It is separated into individual piezoelectric films 12 so as to correspond to each pressure chamber (step S5 in FIG. 5A and FIG. 4).

Next, a common electrode 13 is formed on each piezoelectric film 12 (Step S6 in FIG. 5A and FIG. 4). As shown in FIG. 4, the common electrode may be an individual electrode for each piezoelectric film 12 or may be a continuous electrode over a plurality of piezoelectric films 12.

Next, ₂ μm of SiO ₂ was formed on the common electrode 13.
The diaphragm 4 is formed by forming the vibrating plate 4 to a thickness of FIG.
(A) Step S7). Although not shown in FIG. 4, before forming the vibration plate 4, the vibration plate 4 is formed by embedding resin on both sides of the piezoelectric film 12 and flattening the surface on which the vibration plate 4 is formed.

After forming the above layers on the MgO substrate,
A main body made of stainless steel in which a pressure chamber and an ink flow path are previously formed is joined using an adhesive. Thereby, a pressure chamber and an ink flow path are formed on the diaphragm (FIG. 5).
(A) Step S8). The adhesive used here preferably has a relatively high hardness so as not to absorb the piezoelectric vibration.

Next, the MgO substrate is finally removed with an acidic solution (Step S9 in FIG. 5A). The MgO substrate 10 can be stably dissolved without damaging the piezoelectric film by using a phosphoric acid solution as the acidic solution.

Further, an ink jet head according to the first embodiment is manufactured by attaching a member having, for example, 10 μm diameter discharge ports formed at predetermined intervals to the side surface of the main body.

In the manufacturing method described with reference to FIG. 5A, the piezoelectric film and the individual electrodes 11 are patterned before forming the common electrode 13, but the present invention is not limited to this. 5 (b), the common electrode 13 is formed and Mg
After the O substrate 10 is etched, the piezoelectric film and the Pt individual electrode may be patterned.

According to the manufacturing method described above, a thin piezoelectric film having good piezoelectric characteristics can be formed, and the thin piezoelectric film can be applied to an extremely small pressure chamber by applying the fine processing technology used for manufacturing a semiconductor. Thus, an ink jet head having ejection ports formed at a high density can be manufactured.

For example, in order to manufacture a nozzle head having a density of 150 dpi, the width of the pressure chamber is usually 100 μm.
The partition between adjacent pressure chambers is set to about 66 μm. However, if the thickness of the PZT thin film is set to 5 μm or less, it is possible to process the PZT thin film to a width of 50 μm or less. Can be processed to a size corresponding to a pressure chamber having a width of 100 μm. In addition, 20 μm
It is difficult to process a conventional piezoelectric film having the above thickness into a 50 μm-wide piezoelectric film. In the first embodiment,
Since it is possible to process the piezoelectric film to a width of 20 μm or less, considering the processable shape of the piezoelectric film,
It is also possible to make nozzle heads having a density of 0 dpi or higher. FIG. 6 is a front view of a nozzle head manufactured by this method and having discharge ports (nozzles) formed at a density of 200 dpi. Further, since the width of the pressure chamber can be reduced, the resonance frequency of the pressure chamber can be increased, and there is an advantage that the pressure chamber can be driven at a higher frequency. Further, being able to drive at this high frequency means that the response to the applied voltage can be made faster, which means that it is possible to finely control the ink ejection amount, and thereby it is possible to improve the gradation. it can. The width of the pressure chamber is set to 100 μm (that is, 150 μm).
Assuming dpi), the resonance frequency is about 1 MHz.

Further, the ink discharge performance is generally represented by the product of the deflection amount Y and the generated pressure P. This value is represented by the following equation, where t is the piezoelectric film thickness, d31 is the piezoelectric constant, and V is the voltage. Since it is represented by (1), there is also an advantage that the applied voltage can be reduced when the film thickness is small.

Y · P = k · d312 · V2 / t Equation (1) According to the above method, PZ having a Zr / Ti ratio of 50/50
The T thin film is 10 μm wide and 1 m long corresponding to each pressure chamber 1.
The relationship between the applied voltage and the maximum deflection of the diaphragm 4 was measured using a sample patterned to a size of m. FIG. 7 shows the result. It is understood from FIG. 7 that when the applied voltage is increased, the diaphragm can generate a displacement of about 2 μm with respect to the deflection of 30 V. It was confirmed that an ink jet head having a high ink discharging ability can be manufactured by utilizing the good piezoelectric characteristics.

As described above, in the ink jet head of the first embodiment, the piezoelectric film 5 is constituted by the first layer of perovskite type not containing Zr and the second layer made of PZT containing Zr. It is formed by processing a thin piezoelectric film having excellent piezoelectric characteristics. As a result, a fine piezoelectric film 5 having excellent piezoelectric characteristics can be formed, so that an ink jet head having an ink ejection port which is extremely small and has a high density formed as compared with the conventional ink jet head can be obtained. Can be provided.

In the above description, specific materials and numerals have been appropriately described, but the present invention is not limited to the numerals described above.

With respect to the first layer (initial layer) in the piezoelectric film, as described above, the first layer 8 is a layer for forming the second layer 9 having good crystallinity, and has piezoelectricity. The function as a film is exclusively performed by the second layer 9. Therefore,
The thickness of the first layer 8 is preferably as small as possible so long as the function of forming a favorable second layer is not reduced so that the piezoelectric characteristics of the entire piezoelectric film 5 are not deteriorated. We have confirmed that when a sputtering apparatus having good film thickness controllability is used, even if the first layer 8 is 5 nm or less, its function can be sufficiently exhibited. However, when the Pt electrode is covered evenly and the management in the manufacturing process is taken into consideration, 50n is considered.
It is preferable to set in the range of m to 100 nm. When the thickness is set in this range, the piezoelectric characteristics of the entire piezoelectric film 5 can be substantially prevented from lowering, and the effect of forming the second layer of good quality can be sufficiently achieved. In addition, the piezoelectric film 5 is formed. It is possible to reduce an increase in the process management burden in the process. In the first embodiment, the first layer 8 is a PbTiO ₃ layer having a thickness of 0.1 μm, and the second layer 9 is a PZT layer having a composition of 2.9 μm Pb (Zr _0.53 Ti _0.47 ) O _3. By doing so, it has been confirmed that an ink jet head having a sufficient ink discharge capability can be manufactured even at a low voltage.

In the present invention, the thickness of the second layer 9 made of PZT is not particularly limited. Is preferably set to 10 μm or less. Further, the piezoelectric film 5 is patterned into a predetermined shape corresponding to each pressure chamber after the film formation. However, considering that it is necessary to further narrow the interval between the discharge ports 2 in the future, the accuracy corresponding to the patterning is required. In order to achieve good patterning, the thickness of the piezoelectric film 5 is more preferably set to 5 μm or less. The thickness of the piezoelectric film 5 is set to 0.5 in consideration of the strength of the film and the generated stress.
It is preferable to set it to μm or more. According to our study, it is most preferable to set the thickness of the piezoelectric film 5 in a range of 1 to 3 μm. By setting the thickness in this range, the ink can fly stably and the reliability of the film is kept constant. It has been confirmed that the above can be maintained.

In the first embodiment, the main body 50 is formed by using stainless steel (SUS). However, the present invention is not limited to this, and is constituted by a photosensitive organic polymer material, photosensitive glass, silicon, and the like. Is also good.

The diaphragm 4 can be easily finely processed by using a thin film process such as a sputtering method. In Embodiment 1, the material is silicon oxide SiO _2.
However, the present invention is not limited to this, and metals such as nickel, chromium, and aluminum can be used. These metals could also be easily formed by sputtering, vacuum evaporation and plating, and good vibration characteristics could be obtained as with SiO ₂ . Further, even if alumina was used for the diaphragm 4, the same effect as that of SiO ₂ could be obtained, and it could be easily formed by the sputtering method. In addition, a polyimide resin can be used for the diaphragm 4, and the polyimide resin can be easily formed by spin coating, and its microfabrication is easy, which is suitable for a diaphragm of an ink jet recording apparatus. Material.

Even if the vibration plate 4 is formed using the above-mentioned materials, there is no deterioration such as generation of a crack during the vibration, and vibrations sufficient to discharge the ink can be generated. The same vibration characteristics can be obtained even if an oxide of each metal is used as the material of the diaphragm 4. Further, the use of photosensitive polyimide as the diaphragm 4 facilitates the manufacture of the element.

In the above configuration, the diaphragm 4 facing the pressure chamber 1 is a 2 μm thick SiO ₂ layer, and the second layer 9 of the piezoelectric film 5 is composed of Pb (Zr _0.5 Ti _0.5 ) O ₃ In the case of using the PZT thin film having a thickness of 3 μm and the electrodes 6 and 7 made of platinum having a thickness of 0.1 μm, good flexural vibration could be generated even at a voltage of 50 V or less. However, in the present invention, the thickness of the diaphragm 4 is not limited to the above-mentioned 2 μm, but takes into account the piezoelectric characteristics and thickness of the piezoelectric film 5, the inherent vibration characteristics of the material constituting the diaphragm 4, and the like. Is set as appropriate.

In the present invention, the piezoelectric films 5 and 12 made of a lead-based dielectric layer having a perovskite structure are formed with good crystallinity by using platinum, gold or ruthenium oxide as the electrode 11 on the MgO substrate 10. We were able to. Even if the piezoelectric films 5 and 12 formed on the electrodes made of any material are used, a plurality of the piezoelectric films 5 and 12 with small characteristic variations can be formed, and the variation of the ink ejection capability among the elements can be reduced. be able to.

In the fine processing of a PZT thin film, a strong acid solution such as hydrofluoric acid or nitric acid is used.
By using gold or ruthenium oxide, corrosion of the electrode material can be prevented, and the device can be manufactured stably. Further, PZT used as a piezoelectric material of the second layer constituting the piezoelectric films 5 and 12 has a Z
P having an r / Ti ratio in the range of 30/70 to 70/30
It is preferable to use a ZT layer. In the present invention, as the piezoelectric material that can be used as the second layer, in addition to the above-described PZT, for example, Pb _0.99 Nb
_0.02 [(Zr _0.6 Sn _0.4 ) _1-y Ti _y ] _0.98 O ₃ (0.060 ≦ y
≦ 0.065), and a piezoelectric material containing an element other than Pb, Ti, and Zr can be used. In addition, Pb _0.99
Nb _0.02 [(Zr _0.6 Sn _0.4 ) _1-y Ti _y ] _0.98 O ₃ (0.060 ≦
(y ≦ 0.065) is an antiferroelectric material, but may be used. FIG. 8 shows the relationship between the applied voltage and the maximum displacement of the diaphragm 4 in this case. In this case, a phase transition from an antiferroelectric substance to a ferroelectric substance occurred at a voltage of 15 V, so that a discontinuous displacement characteristic was exhibited, and a displacement of about 0.8 μm occurred at 20 V. When a voltage of 20 V or more was applied, a substantially constant displacement could be generated, and the variation in the ink ejection amount could be reduced. Furthermore, Pb _0.99 Nb _0.02 [(Z
r _0.6 Sn _0.4 ) _1-y Ti _y ] _0.98 O ₃ (0.060 ≦ y ≦ 0.065)
With the antiferroelectric thin film having the following composition, a piezoelectric element having stable ink ejection ability was able to be formed even with a polycrystalline thin film.

In the first embodiment, PbTiO ₃ containing no Zr or PLT in which lanthanum is added to PbTiO ₃ is formed as the first layer 8, and Pb is formed as the second layer 9.
Although an example in which a layer having a composition of (Zr _0.53 Ti _0.47 ) O ₃ is formed is shown as the most preferable example, the present invention is not limited to this. As the piezoelectric material of the first layer (initial layer) constituting the piezoelectric films 5 and 12, a PZT layer made of Pb (Zr _x Ti _1-x ) O ₃ set to x <0.3 or a La layer is further added to the layer. And a second layer having 0.7 ≧ x
Even if it is formed using a PZT layer made of Pb (Zr _x Ti _1-x ) O ₃ set to ≧ 0.3, a second layer having good crystallinity and a relatively large piezoelectric constant is formed. Can be.
In this case, it is preferable to use, as the first layer, a PZT layer made of Pb (Zr _x Ti _1-x ) O _{3 where} x <0.2 or a layer further containing La.

(Embodiment 2) FIGS. 9 and 10 are views for explaining a method of manufacturing an ink jet head according to Embodiment 2 of the present invention. The manufacturing method according to the second embodiment is substantially the same as the manufacturing method described in the first embodiment except that a Si substrate is used instead of the MgO substrate.

In this manufacturing method, first, as shown in FIGS.
A layer was formed, and a piezoelectric film 12 made of a lead-based dielectric layer was formed as a piezoelectric material on the individual electrode 11 by a sputtering method. Here, as in the first embodiment, the piezoelectric film 12 made of a lead-based dielectric layer is formed by forming a first layer made of a lead-based dielectric not containing Zr and then forming a second layer made of PZT containing Zr. It is formed by forming. The piezoelectric film 12 configured as described above is a polycrystalline body, and has a Z layer as a first layer.
After forming a first layer made of a lead-based dielectric containing no r,
Since the second layer made of PZT containing Zr is formed,
The second layer having extremely good piezoelectric characteristics can be formed. By forming a PZT-based polycrystalline layer with a thickness of 3 μm as the piezoelectric film 12, good piezoelectricity could be obtained. As a method of forming the piezoelectric film 12, a piezoelectric thin film having good crystallinity could be formed by MOCVD or spin coating using a sol-gel solution instead of the above-described sputtering method. Next, a Pt layer serving as the common electrode 13 is formed on the piezoelectric film 12. In the case of using a spin coating method using a sol-gel solution, first, a sol-gel solution containing no Zr as a first layer is coated, and a sol-gel solution containing Zr as a second layer is formed to a predetermined thickness. After coating, firing is performed to form the piezoelectric film 12. As described above, similarly to the sputtering method, the piezoelectric film 12 as a polycrystalline layer can be formed.

The vibration plate 4 was formed on the common electrode 13 with a material made of SiO ₂ by sputtering. Next, after a main body having the pressure chamber 1 formed of a photosensitive resin is provided on the vibration plate 4, the silicon substrate 15 is finally removed by etching with a hydrofluoric acid solution or a potassium hydroxide solution. The pressure chamber 1 is formed in the main body by dividing it with photosensitive glass or photosensitive resin so as to correspond to each discharge port. In FIG. 10, the individual electrodes 11 are patterned before the formation of the piezoelectric film 12, but may be patterned after the silicon substrate 15 is etched. Further, in FIG. 10, the piezoelectric film 12 is patterned before forming the common electrode 13, but after the silicon substrate 15 is removed by etching, the piezoelectric film 12 is patterned so as to be divided into the respective pressure chambers 1. You may. According to the manufacturing method shown in the present embodiment,
It is possible to use a silicon substrate 15 which is cheaper than the MgO substrate 10 and easily obtains a single-crystal substrate having a large area. The material can be formed. In addition, it becomes easy to increase the number of elements produced by very high-precision microfabrication by applying the silicon microfabrication technology that has been established up to now. The ink jet head manufactured by the above-described method can have the same configuration as that of FIG. 6 and the nozzles have a density of 200 dpi. Further, it is also possible to manufacture an ink jet head having high-density nozzles. In manufacturing an ink jet head having this configuration, an ink jet head having a similar multi-element configuration can be manufactured by using a glass substrate instead of using the silicon substrate 15. In this case, by etching the glass substrate using a hydrofluoric acid-based solution, a multi-element inkjet head having the same configuration as in FIG. 6 could be formed.

By using ruthenium oxide in addition to platinum as the individual electrode 11, the piezoelectric film 12 having a perovskite structure could be formed with good crystallinity. As a result, the piezoelectric film can have good characteristics, and an ink jet head having a small variation in ink discharge capability among the elements can be produced even when the number of elements is increased. The piezoelectric film 12 used as a piezoelectric material is made of Zr / T
With a PZT layer having an i-ratio in the range of 30/70 to 70/30, an inkjet head having even better piezoelectric characteristics and a high ink-discharging ability could be obtained. Further, as the piezoelectric film 12, Pb _0.99 Nb _0.02 [(Zr _0.6 Sn
_0.4 ) _1-y Ti _y ] _{0.98 When} using an antiferroelectric thin film having a composition of O ₃ (0.060 ≦ y ≦ 0.065), a stable response to voltage application can be obtained, and the ink ejection amount Was reduced.

Further, in addition to silicon oxide SiO ₂ , metals such as nickel and aluminum can be easily formed by sputtering, vacuum deposition and plating as a material of the diaphragm 4, and have good vibration characteristics similar to SiO _2. I got it. Also, oxides such as alumina can be used in the form of SiO ₂
The same effect as described above can be obtained, and the film can be easily formed by the sputtering method. In addition, a high molecular organic material such as a polyimide resin can be easily formed by a spin coating method, and the processing thereof is also easy, so that the material is suitable for a diaphragm of an ink jet head.

(Embodiment 3) FIGS. 11 and 12 are diagrams illustrating a method of manufacturing an ink jet head according to Embodiment 3 of the present invention.

[0075] In this manufacturing method, first, as shown in FIG. 11, 12, SiO ₂ film thickness 2μm on the silicon substrate 15
Is formed by sputtering or thermal oxidation of a silicon substrate. Further, a Pt layer serving as the common electrode 13 is formed thereon. The piezoelectric film 12 made of a lead-based dielectric was formed on the common electrode 13 by rf sputtering. Here, the piezoelectric film 12 is formed similarly to the first embodiment.
It is formed by forming a first layer made of a lead-based dielectric not containing Zr and then forming a second layer made of PZT containing Zr. Piezoelectric film 12 configured as above
Is a polycrystalline, but after forming a first layer made of a lead-based dielectric not containing Zr as a first layer, a PZ containing Zr is formed.
Since the second layer made of T is formed, the second layer having extremely good piezoelectric characteristics can be formed. By forming a PZT-based polycrystalline layer having a thickness of 3 μm as the piezoelectric film 12, excellent piezoelectric characteristics could be obtained. As a method of forming the piezoelectric film 12, a piezoelectric thin film having good crystallinity was able to be formed even by MOCVD or spin coating using a sol-gel solution. Next, a Pt layer serving as the individual electrode 11 is formed on the piezoelectric film 12. The individual electrodes 11 were finely processed by ion etching so as to be separated into portions corresponding to the respective pressure chambers 1. When the vibration plate 4 is an insulator, the individual electrodes 11 may be formed on the vibration plate 4 and the common electrode 13 may be formed on the piezoelectric film 12.

Next, the silicon substrate 15 is partially removed by etching with a hydrofluoric acid solution or a potassium hydroxide solution.
A part of the silicon substrate 15 was used as a structural member of the pressure chamber 1. Before forming the common electrode 13, the piezoelectric film 12 was patterned so as to have a divided shape corresponding to each pressure chamber 1. In this method, since the pressure chamber 1 is formed using a part of the substrate on which the piezoelectric element is formed, the process can be simplified, and a fine element can be formed by using a silicon fine processing technique. The ink jet head manufactured by the above method can have the same configuration as that of FIG. 6, and the nozzles can be formed at a density of 200 dpi or more. In the manufacture of the inkjet head having this configuration, the silicon substrate 1
In addition to using No. 5, an inkjet head having a similar multi-element configuration could be manufactured using a cheaper glass substrate. In this case, by etching the glass substrate 13 using a hydrofluoric acid-based solution, a multi-element inkjet head having the same configuration as in FIG. 6 could be formed.

By using ruthenium oxide in addition to platinum as the individual electrode 11, the piezoelectric film 12 having a perovskite structure could be formed with good crystallinity. As a result, the piezoelectric film can have good characteristics, and an ink jet head having a small variation in ink discharge capability among the elements can be produced even when the number of elements is increased. The piezoelectric film 12 used as a piezoelectric material is made of Zr / T
With a PZT layer having an i-ratio in the range of 30/70 to 70/30, an inkjet head having even better piezoelectric characteristics and a high ink-discharging ability could be obtained. Further, as the piezoelectric film 12, Pb _0.99 Nb _0.02 [(Zr _0.6 Sn
_0.4 ) _1-y Ti _y ] _0.98 O ₃ (0.060 ≦ y ≦ 0.065)
When an antiferroelectric thin film having the following composition was used, a stable response to voltage application could be obtained, and variations in the ink ejection amount could be reduced. Pb _0.99
Nb _0.02 [(Zr _0.6 Sn _0.4 ) _1-y Ti _y ] _0.98 O ₃ (0.0
With the antiferroelectric thin film having the composition of 60 ≦ y ≦ 0.065), a piezoelectric element having a stable ink ejection ability was able to be formed even with a polycrystalline thin film.

Further, as the material of the vibration plate 4, in addition to silicon oxide SiO ₂ , metals such as nickel and aluminum can be easily formed by sputtering, vacuum deposition and plating, and have good vibration characteristics similar to SiO _2. I got it. Also, the same effect as SiO ₂ can be obtained with alumina, and it was easily formed by the sputtering method. In addition, a polyimide resin can be easily formed by spin coating, and its processing is also easy.
The material was suitable for a diaphragm of an inkjet head.

(Embodiment 4) FIG. 13 (a) is a perspective view of an ink jet head 200 according to Embodiment 4 of the present invention, and FIG. 13 (b) is a sectional view taken along line CC 'of FIG. FIG. FIG. 14 is a cross-sectional view taken along line DD ′ of FIG.

The ink jet head 200 has a main body 250 having a plurality of discharge ports 202, pressure chambers 201 provided corresponding to the respective discharge ports 202, and a vibration provided on the upper surface of the main body 250. The plate 204 and the diaphragm 20
4 and a piezoelectric element 203 provided on the same.

In the main body 250, the discharge ports 202 are formed at predetermined intervals on the lower surface of the main body 250, and
1 is a main body 2 so as to correspond to the discharge ports 202, respectively.
50 are formed side by side. Each ejection port 202 and the corresponding pressure chamber 201 are connected via an ink flow path 202 a formed in the main body 250. Note that the main body 250 is made of a highly rigid material such as resin, glass, stainless steel, ceramic, and silicon.

The piezoelectric element 203 is, as shown in FIG.
A common electrode 208 formed on the vibration plate 204, a piezoelectric body 205 formed on the common electrode 208 at a predetermined interval corresponding to each pressure chamber 201, and an individual electrode provided on each piezoelectric body 205 209 and adjacent piezoelectric bodies 5
A filler made of a polyimide resin is embedded between them. Here, the piezoelectric body 205 forms PtTiO ₃ containing no Zr or PLT in which lanthanum is added to PbTiO ₃ , as in the first embodiment,
As the second layer 9, a layer having a composition of Pb (Zr _0.53 Ti _0.47 ) O ₃ was formed to a thickness of about 3 μm. As a result, as in the first embodiment, a piezoelectric body 205 having good piezoelectric characteristics is formed.

The vibration plate 204 is made of a 2 μm-thick alumina layer formed by a sputtering method.
8 and the individual electrodes 209 were each formed of a 0.1 μm Pt layer. As a material of the diaphragm 204, in addition to alumina, Ni, Cr, Ti, Al, Zr can be used. Regardless of which material is used, adhesion and vibration characteristics with the piezoelectric body 205 and the electrode material can be improved. Are better. Also,
In the present invention, an oxide of Ni, Cr, Ti, Al, Zr,
Further, a silicon oxide and a resin material can be used. The thickness of the vibration plate 204 is preferably equal to or less than the thickness of the piezoelectric body 205 in order to obtain good ink ejection performance.

The piezoelectric body 205 is preferably formed such that the width of the piezoelectric body 205 is smaller than the width of the corresponding pressure chamber. However, the present invention is not limited to this. By using one unseparated piezoelectric film and forming the individual electrode 209 corresponding to each pressure chamber 201, each pressure chamber among the piezoelectric layers is formed. The ink may be ejected by vibrating only the portion corresponding to.

The filler 210 buried between the adjacent piezoelectric members 205 is not limited to the above-described polyimide resin, but may be any material having a relatively low rigidity. By using a material having a relatively low rigidity as the filler as described above, the piezoelectric body can be vibrated without obstructing the expansion and contraction of the piezoelectric body 205 in the horizontal direction, so that the vibration characteristics are not deteriorated.

For example, when the width of the pressure chamber 201 is set to 70 μm and the width of the piezoelectric body 205 is formed to be slightly smaller than the width of the pressure chamber 201, a maximum of 50 nm can be changed by applying a voltage of 10V. did it.

As described above, in the fourth embodiment,
As in the first embodiment, the piezoelectric body 205 is formed using a thin film forming method such as sputtering as a double structure of the first layer and the second layer. Thus, good vibration characteristics could be obtained with a relatively simple configuration. This is the piezoelectric body 20
This is because a piezoelectric film having good crystallinity can be formed as No. 5, and a normal sintered body can be driven by applying a high voltage that causes dielectric breakdown. Further, as in the first embodiment, the piezoelectric body 205 can be made extremely thin, so that miniaturization is easy and 200 d
A head having a nozzle density of pi can be easily manufactured.

As a method of forming the piezoelectric body 205, other thin film forming methods such as a CVD method may be used in addition to the spin coating described above.

The thickness of the piezoelectric body 205 is 10 μm.
m or more, fine processing becomes difficult.
It is preferable that the thickness of 05 is set to 10 μm or less.

In the fourth embodiment, the piezoelectric body 205
As in Embodiment 1 or Embodiment 2, a substrate formed using an MgO substrate or a Si substrate is used.

That is, a single crystal MgO substrate cleaved such that the (100) plane appears on the surface is used as the substrate.
After forming an initial layer containing no Zr on the (100) plane of the MgO substrate, a general formula (Pb _1-x La _x ) is formed on the initial layer.
By forming the piezoelectric body represented by (Zr _1-y Ti _y ) O ₃ , a piezoelectric body oriented in the c-axis can be formed. As described above, by adding La to the piezoelectric body represented by the general formula Pb (Zr _{1 -y} Ti _y ) O ₃ , the crystallization temperature can be lowered and the piezoelectricity of the thin film piezoelectric body can be improved. Can be. Further, the single crystal (Pb _1-x La _x ) (Zr _1-y Ti _y ) O ₃ thus formed has a piezoelectric constant 1.5 times that of the polycrystal having the same composition. Obtainable. As a method of forming the piezoelectric body 205,
By using a sputtering method or a CVD method, a single-crystal film with good crystallinity can be formed at a high deposition rate of 1 μm or more per hour. Further, by using platinum or ruthenium oxide as an electrode material, a piezoelectric film can be grown while maintaining good interface characteristics. In addition, when platinum or ruthenium oxide is used as an electrode, it is also possible to use silicon or glass, which can be easily micro-processed, or a highly rigid stainless material, as well as MgO, as a substrate material, thereby reducing the head manufacturing cost. Can be.

Further, the general formula (Pb _1-x La _x ) (Zr _1-y
When a piezoelectric film represented by Ti _y ) O ₃ is formed on a platinum or ruthenium oxide electrode, the composition of the portion in contact with the electrode, particularly, y is set to 0.7 or more (the ratio of Zr is reduced). By doing so, deposition of an impurity layer such as an oxide of Zr on the electrode can be suppressed, and the piezoelectric body 205 having good crystallinity can be formed. Therefore, by forming the above-mentioned Zr-reduced initial layer immediately above the electrode and forming a few μm thick piezoelectric film having a large piezoelectric constant with y set to 0.7 or less on the initial layer, The piezoelectric body 205 having a high piezoelectric constant can be formed with good crystallinity.

Also, since the ink jet head of the present invention is formed using the thin piezoelectric member and the vibration plate as described above, it is necessary to pay attention to the adhesion between the main body in which the pressure chamber is formed and the vibration plate. is there. That is, when the partition wall of the main body and the diaphragm are joined with an adhesive, a large stress is applied to the thin piezoelectric member 205 due to shrinkage due to the curing of the adhesive, which may cause cracking or peeling. In addition, even if cracking or peeling does not occur, stable vibration is hindered.

Therefore, in the fourth embodiment, as shown in FIG. 16, a resin layer 212 having a film thickness of about 2 μm and a low rigidity is used.
It is preferable that the partition wall 207 of the main body and the diaphragm 204 are joined through the intermediary of the main body. The resin layer 212 is made of, for example, polyimide and can be formed by using a spin coating method or the like. In FIG. 16, what is denoted by reference numeral 213 is an adhesive.

As described above, the resin layer 2 made of polyimide
By providing 12, the shrinkage of the adhesive 213 causes
It is possible to prevent stress from being applied to the piezoelectric body 205,
5 was able to be vibrated stably, and at the same time, damage and the like were prevented. In addition, the polyimide resin prevents the ink from directly contacting the vibration plate, so that the life can be improved. The thickness of the resin layer 212 is preferably 3 μm or less, and if the thickness is 3 μm or more, the vibration of the diaphragm is absorbed by the resin layer, and the ink ejection performance is effectively deteriorated.

Further, in order to effectively exhibit the ink ejection performance and suppress variations in the ejection amount and the ejection speed of the ink, it is necessary to accurately control the amounts and thicknesses of the resin layer 212 and the adhesive 213. . FIG.
A 7 μm-thick alumina layer 2 is formed on a portion of the piezoelectric vibrating portion (composed of a piezoelectric element and a diaphragm) 230 to be bonded to a partition wall.
14 is formed. This alumina layer 214
After forming a film having a thickness of 7 μm on the piezoelectric vibrating part 230,
It is formed by wet etching with an acid, leaving a portion for the partition. As described above, by joining the partition wall 207 and the piezoelectric vibrating section 230 via the alumina layer 214, the pressure chamber 20 of the piezoelectric vibrating section 230 is joined.
It is possible to vibrate only in the portion located on the upper side, and it is possible to reduce variations in ink ejection amount and the like. In the present invention, instead of the alumina layer 214,
Highly rigid resins such as ceramics and epoxy resins made of various metal oxides, Cr and the like may be used. That is,
A material having good adhesion to the piezoelectric vibrating portion 230 and capable of fine processing can be used.

In the above piezoelectric vibrating section, the piezoelectric body 205 is
Although the configuration is made up of layers, the present invention is not limited to this, and may be made up of two layers of a piezoelectric body 205a and a piezoelectric body 205b as shown in FIG. In this case, the individual electrodes 209 are
The electrode 209a formed on the electrode 05a and the electrode 209b formed below the piezoelectric body 205b are divided into two parts. An intermediate electrode 211, which is a common ground electrode, is provided between the piezoelectric body 205a and the piezoelectric body 205b. Form. As described above, by configuring the piezoelectric body 205 with two layers of the piezoelectric bodies 205a and 205b, it is possible to obtain a displacement twice as large as the case where the piezoelectric body 205 is configured with one layer. The piezoelectric bodies 205a and 205b are respectively
It comprises an initial layer (first layer) and a second layer. In addition, in such a configuration, since the flexural vibration is generated by the piezoelectric bodies 205a and 205b, the diaphragm 204 that generates vibration in cooperation with the piezoelectric body becomes unnecessary in principle, and the piezoelectric body is protected from ink. For example, it is only necessary to form a resin layer of about 1 μm. In other words, in the configuration shown in FIG.
The piezoelectric vibrating section is constituted by providing two layers of the piezoelectric bodies 205a and 205b without providing the vibration plate.

(Embodiment 5) FIG. 18 is a partial sectional view showing the structure of an ink jet head according to Embodiment 5 of the present invention. The ink jet head of Embodiment 5 is manufactured by the following procedure. Is done.

First, a Pt layer serving as a common electrode 208 is formed on a single-crystal silicon substrate, and a film thickness 3 corresponding to each pressure chamber is formed on the common electrode 208 in the same manner as in the first embodiment.
A μm piezoelectric body 205 and individual electrodes 209 are formed. Then, on the individual electrode 209, a film thickness 2 that becomes the diaphragm 204a
To form an alumina layer. The space between the adjacent piezoelectric bodies 205 is filled with a filling resin 210 made of polyimide resin. Next, the silicon substrate is
(a silicon pedestal 15) corresponding to the partition wall that separates each pressure chamber from the polished silicon substrate.
Is etched using an alkaline solution such as a KOH aqueous solution, for example. Then, the partition of the main body in which the pressure chamber made of stainless steel, resin or glass is formed and the silicon pedestal 15 are opposed to each other and bonded to produce the ink jet head of the fifth embodiment shown in FIG. In the fifth embodiment, the width of the pressure chamber 201 is, for example,
It is set to 70 μm.

As described above, in the ink jet head according to the fifth embodiment, the silicon substrate is finely processed to form a pressure chamber using a part of the silicon substrate, and the bonding portion with the main body is separated from the piezoelectric body. Therefore, the deterioration of the vibration characteristics due to the influence of the bonding portion can be substantially eliminated. Therefore, in the ink jet head according to the fifth embodiment, variations in the ink ejection performance can be extremely reduced. In this embodiment, when the piezoelectric layer 205 is formed, an initial layer made of (Pb _0.95 La _0.05 ) TiO ₃ is formed. On the common electrode 208 made of Pt, a low substrate temperature of 500 ° C. It was confirmed that an initial layer having good crystallinity could be formed. The ability to form the initial layer at such a low temperature is extremely useful in practice.

In the fifth embodiment, quartz glass can be used as a substrate instead of a silicon substrate. When this quartz glass is used, etching with hydrofluoric acid can be used for fine processing of the substrate. The head can be manufactured at low cost. In addition, (1)
By using the MgO substrate oriented on the (00) plane,
As described in the first embodiment, the piezoelectric body 205 made of Pb (Zr _0.53 Ti _0.47 ) O ₃ oriented in the c-axis can be formed on the Pt electrode with the initial layer interposed therebetween. It is possible to obtain a piezoelectric constant about 1.5 times that of a piezoelectric body made of a polycrystalline thin film. Similarly, when an MgO substrate is used, the substrate is polished or etched to a thickness of about 0.1 mm, then processed as shown in FIG. 18, and that portion can be joined to the partition of the main body. .

(Embodiment 6) FIG. 19 shows Embodiment 6 of the present invention.
FIG. 3 is a perspective view illustrating a configuration of an inkjet head of FIG. The ink jet head according to the sixth embodiment includes a main body 350 formed by laminating four stainless steel plates 351, 352, 353, and 354, and a piezoelectric member provided to close a pressure chamber 301 formed in the main body 350. A vibrating portion (consisting of a piezoelectric element 303 and a vibrating plate 304). In addition,
In the main body 350, the ink discharge port 302 is
As shown in FIG. 5, the ink chambers 301 provided side by side in the width direction on the lower surface of the stainless steel plate 354 and separated by partition walls (not shown) are provided corresponding to the respective ink ejection ports 302. The piezoelectric element 303 includes a common electrode (not shown), a piezoelectric film 305, and an individual electrode 309. The individual electrode 309 is formed directly above each pressure chamber 301, and an individual electrode 309 corresponding to each pressure chamber 301 is provided. A piezoelectric element is configured. Here, the piezoelectric film 305 is configured similarly to the first to fifth embodiments.

In the sixth embodiment, the stainless steel plate 3
Although the main body 350 is formed using 51 to 354, the present invention is not limited to this, and the main body may be formed by laminating glass plates. Further, the main body having the structure shown in FIG. 19 may be formed using resin.

[0104]

As described in detail above, according to the present invention, a thin film having a large piezoelectric constant as compared with the conventional example can be formed by using a thin film forming method such as a sputtering method and a CVD method. Since it can be formed, fine processing of the piezoelectric film becomes possible, an ink ejection port is formed at high density, and a small head for an ink jet recording apparatus capable of high-speed response can be provided. Therefore, by using this small-sized inkjet head having ejection ports formed at high density, it is possible to realize an inkjet recording apparatus capable of high-speed printing at high resolution.

[Brief description of the drawings]

FIG. 1A is a perspective view illustrating a configuration of an inkjet head according to a first embodiment. FIG. 1B is a cross-sectional view taken along line AA ′ in FIG.

FIG. 2 is an enlarged partial cross-sectional view illustrating a piezoelectric vibrating portion of the inkjet head according to the first embodiment.

FIG. 3 is an enlarged partial cross-sectional view showing a piezoelectric film 5 in the ink jet head according to the first embodiment.

FIG. 4 is a cross-sectional view when a piezoelectric vibrating portion is formed on the MgO substrate 10 in the method of manufacturing the ink jet head according to the first embodiment.

5A is a process chart showing main steps of an example of a manufacturing method of the ink jet head according to the first embodiment. FIG. 5B is a process chart showing an example different from FIG.

FIG. 6 is a front view of the inkjet head according to the first embodiment.

FIG. 7 is a diagram illustrating a deflection amount of a diaphragm with respect to an applied voltage in an example of the inkjet head according to the first embodiment;

FIG. 8 is a diagram illustrating a deflection amount of a diaphragm with respect to an applied voltage in another example of the inkjet head according to the first embodiment.

FIG. 9 is a cross-sectional view when a piezoelectric vibrating portion is formed on a silicon substrate 15 in the method of manufacturing an ink jet head according to the second embodiment.

FIG. 10 is a process chart showing main steps of a method for manufacturing an ink jet head according to the second embodiment.

FIG. 11 is a partial cross-sectional view showing features of an ink jet head manufactured by the manufacturing method according to the third embodiment.

FIG. 12 is a process chart showing main steps of a method for manufacturing an ink jet head according to the third embodiment.

13A is a perspective view showing a configuration of an inkjet head according to a fourth embodiment. FIG. 13B is a cross-sectional view taken along line CC ′ of FIG.

FIG. 14 is a sectional view taken along line D-D ′ of FIG.

FIG. 15 is a partial cross-sectional view illustrating a configuration of a piezoelectric vibrating unit according to a modification of the fourth embodiment.

FIG. 16 is a partial cross-sectional view showing a preferred connection structure according to the fourth embodiment.

FIG. 17 is a partial cross-sectional view showing another preferred connection structure according to the fourth embodiment.

FIG. 18 is a partial cross-sectional view illustrating a configuration of an inkjet head according to a fifth embodiment.

FIG. 19 is a perspective view showing a configuration of an inkjet head according to a sixth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure chamber 2 Discharge port 3 Piezoelectric element 4 Vibration plate 5 Piezoelectric film 6, 7 Electrode 8 1st layer 9 2nd layer 30 Piezoelectric vibrating part 50 Main part

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoru Fujii 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (25)

[Claims] 1. A main body having an ink discharge port, a pressure chamber connected to the ink discharge port, a piezoelectric film containing lead, titanium, and zirconium, and electrodes provided on both sides of the piezoelectric film. A piezoelectric vibrating portion provided in a part of the pressure chamber, wherein the piezoelectric vibrating portion bends and vibrates to eject ink from an ink discharge port by causing ink to flexibly vibrate, wherein the piezoelectric film has
An ink jet head comprising: a first layer having a perovskite structure containing strontium or barium; and a second layer having a perovskite structure having lead, titanium, and zirconium formed so as to be in contact with the first layer. Recording device. 2. A main body having an ink discharge port, a pressure chamber connected to the ink discharge port, a piezoelectric film containing lead, titanium, and zirconium, and electrodes provided on both sides of the piezoelectric film. A piezoelectric vibrating portion provided in a part of the pressure chamber, wherein the piezoelectric vibrating portion bends and vibrates to eject ink from an ink discharge port by causing ink to flexibly vibrate, wherein the piezoelectric film has
It comprises a first layer and a second layer each having a perovskite structure and formed in contact with each other, wherein the content of zirconium in the first layer is smaller than the content of zirconium in the second layer. An ink jet head recording apparatus characterized in that the number is small. 3. A main body having an ink discharge port, a pressure chamber connected to the ink discharge port, a piezoelectric film containing lead, titanium, and zirconium, and electrodes provided on both sides of the piezoelectric film. A piezoelectric vibrating portion provided in a part of the pressure chamber, wherein the piezoelectric vibrating portion bends and vibrates to eject ink from an ink discharge port by causing ink to flexibly vibrate, wherein the piezoelectric film has
An ink jet head recording apparatus comprising: a first layer having no zirconium and a second layer having zirconium, each of which has a perovskite structure and is formed so as to be in contact with each other. 4. The method according to claim 2, wherein the first layer contains lanthanum.
Or the inkjet head recording device of 3. 5. The ink-jet head recording apparatus according to claim 1, wherein the zirconium / titanium ratio in the second layer is set to 30/70 or more and 70/30 or less. 6. The ink jet head recording apparatus according to claim 1, wherein the piezoelectric film is a single crystal. 7. The ink jet head recording apparatus according to claim 1, wherein the piezoelectric film has a thickness of 10 μm or less. 8. The ink jet head recording apparatus according to claim 7, wherein the piezoelectric film is formed to a thickness of 1 μm or more and 3 μm or less. 9. The ink-jet head recording apparatus according to claim 7, wherein the first layer has a thickness of 50 nm or more and 100 nm or less. 10. The ink jet head recording apparatus according to claim 1, wherein the piezoelectric vibrating section further includes a vibration plate, and the piezoelectric vibrating section flexibly vibrates. 11. The vibration plate is at least one selected from the group consisting of nickel, chromium, aluminum and their oxides, silicon, silicon oxide, and high molecular organic matter.
The ink jet head recording apparatus according to claim 10, which is made of one material. 12. A piezoelectric vibrating part, wherein a piezoelectric film, which is opposed to the piezoelectric film and is interposed between the electrodes via an intermediate electrode layer, is provided separately from the piezoelectric film, and the two piezoelectric films cause flexural vibration. Item 10. The inkjet head recording apparatus according to any one of Items 1 to 9. 13. The ink-jet head recording apparatus according to claim 1, wherein the second layer of the piezoelectric film contains niobium and tin and has antiferroelectricity. 14. The first layer, wherein the zirconium concentration is distributed so as to continuously increase in the thickness direction and is in contact with the second layer on one surface having a high zirconium concentration. 14. The ink jet head recording apparatus according to any one of the thirteenth aspect. 15. An electrode layer provided on both sides of a piezoelectric film,
The ink-jet head recording apparatus according to any one of claims 1 to 14, which is formed of platinum or gold. 16. The main body section has a plurality of ink ejection ports and a plurality of pressure chambers provided respectively corresponding to the respective ink ejection ports, and at least one of the electrodes provided on both sides of the piezoelectric film is provided. The ink jet head recording apparatus according to any one of claims 1 to 15, wherein a piezoelectric vibrating portion corresponding to each pressure chamber is configured by being provided separately so as to correspond to the pressure chamber. 17. The ink jet head recording apparatus according to claim 16, wherein a piezoelectric film is separately provided so as to correspond to the pressure chamber, and one electrode is formed on each of the separated piezoelectric films. 18. A resin having a low rigidity that does not hinder expansion and contraction of the piezoelectric film is filled between the separated piezoelectric films.
7. The ink jet head recording apparatus according to 6. 19. The piezoelectric vibrating portion according to claim 1, wherein a peripheral portion of the piezoelectric vibrating portion has elasticity with a peripheral portion of the pressure chamber via a resin layer having a thickness of 3 μm or less. 1
Item 6. An ink jet head recording apparatus according to item 1. 20. The piezoelectric vibrating portion according to claim 1, wherein a peripheral portion thereof is joined to a peripheral portion of the pressure chamber via a base made of ceramic, metal or resin.
Item 6. An ink jet head recording apparatus according to item 1. 21. A main body having an ink discharge port and a pressure chamber connected to the ink discharge port and partially having an opening, and a piezoelectric vibrating section provided to cover the opening. A method for manufacturing an ink jet head recording device comprising: forming a first layer having a perovskite structure containing lead and titanium on a substrate, and forming a perovskite structure containing zirconium, lead and titanium on the first layer. Forming a piezoelectric film including the first layer and the second layer by forming a second layer having the first layer, and forming a piezoelectric vibrating portion having the piezoelectric film on the substrate. When,
A second step of joining the peripheral portion of the opening of the body portion and a peripheral portion of the piezoelectric vibrating portion so as to face each other, and a third step of removing the substrate after the joining, wherein the first step includes: A method for manufacturing an ink-jet head recording apparatus, wherein the first layer is formed so as not to contain zirconium or to have a smaller amount of zirconium than the second layer. 22. The method according to claim 21, wherein the first layer and the second layer are formed by sputtering. 23. The method according to claim 21, wherein a magnesium oxide substrate is used as the substrate, and in the third step, the substrate is removed by etching using phosphoric acid. 24. The method according to claim 21, wherein a silicon substrate or a glass substrate is used as the substrate. 25. The method according to claim 24, wherein, in the third step, the substrate is removed by etching using a hydrofluoric acid-based solution or a potassium hydroxide solution.