JP3202006B2 - Piezoelectric element, method of manufacturing the same, ink jet head using the same, and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element, a method of manufacturing the same, an ink jet head using the piezoelectric element, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, printers using ink jet heads as printing devices for personal computers and the like have been widely used because of their good printing performance , easy handling, and low cost.

The ink jet head generates bubbles in the ink by thermal energy and discharges ink droplets by a pressure wave generated by the bubbles, the ink jet head suctions and discharges ink droplets by electrostatic force, and vibrations such as a piezoelectric element. There are various systems, such as those using pressure waves generated by a child.

In general, a device using a piezoelectric element is provided, for example, with an ink supply chamber communicating with an ink discharge port, a pressure chamber communicating with the ink supply chamber, and a pressure chamber.
It is composed of a diaphragm or the like to which a piezoelectric element is joined.
Conventionally, the direction of ink ejection and the direction of vibration of the piezoelectric element are the same. In such a configuration, when a predetermined voltage is applied to the piezoelectric element, the piezoelectric element expands and contracts, causing the piezoelectric element and the diaphragm to vibrate in a drum-like shape, compressing the ink in the pressure chamber, and thereby causing the ink ejection port , Ink droplets are ejected. 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 ink jet
Possible to achieve high resolution and high speed printing using a collector head of multi-nozzle head structure finer has been tried.
The miniaturization of the ink jet head, miniaturization of the piezoelectric elements for supplying ink has been demanded strongly. In order to reduce the size of the piezoelectric element, a method is possible in which the thickness of the piezoelectric body is reduced, a flexural vibration is generated using a diaphragm, and ink is ejected. However, the amount of displacement of the piezoelectric body itself with respect to the voltage is very small. Therefore, when the piezoelectric element is miniaturized, sufficient stress or vibration is not generated due to a decrease in piezoelectricity, and ink cannot be ejected. Therefore, small size, high resolution having a multi-nozzle head, also developed a piezoelectric thin film material having sufficient piezoelectric properties in thin thickness in order to realize a high-speed printer, it is necessary to establish a method of manufacturing .

[0005]

However, a small piezoelectric element used for an actuator or a sensor and an ink jet head using the piezoelectric element have been realized by using a thin piezoelectric material as described above. Could not. In particular, in the case of a piezoelectric material of a sintered body that has been conventionally used, the element has been reduced in size by mechanical processing such as cutting. However, mechanical processing has a limitation in downsizing and causes deterioration of piezoelectric characteristics, It was difficult to achieve both miniaturization and high resolution.

The present invention solves the above-mentioned problems of the conventional piezoelectric element. By thinning a piezoelectric body or a vibration plate constituting the piezoelectric element, fine processing generally used in a semiconductor process can be performed. To develop a thin film material that has a large shape and a large piezoelectric property even if the film thickness is thinner, and to provide a structure in which the nozzle structure of the ink jet head realizes high-density multi-element and a manufacturing method thereof. It is intended for.

[0007]

According to the first aspect of the present invention, a common electrode and lead (Pb) are provided on the common electrode.
Zirconium (Zr), titanium (Ti) as a main component,
Consists of several layers with different zirconium compositions
Multilayer structure or zirconium composition changes continuously
Of Perovskite-Type Dielectric Thin Film with Growing Gradient Composition Structure
And an individual electrode laminated on the piezoelectric body.
And, and Pb of the piezoelectric, the composition ratio of Zr and Ti: P
b / (Zr + Ti) is greater than 1 and 1.3 or less.

With the above structure, a high-quality piezoelectric thin film is formed.
Therefore, the piezoelectric properties of the piezoelectric body are improved, the actuator can be driven at a low voltage, and the sensitivity of the sensor can be improved.

According to a second aspect of the present invention, the thickness of the piezoelectric body is 0.5 μm to 5 μm.

According to the above-described structure, the density can be increased by forming a thin film, and a small-sized and high-resolution piezoelectric element can be manufactured.

According to the third aspect of the present invention, on the substrate,
An individual electrode is formed, and lead (Pb), di-
Containing ruconium (Zr) and titanium (Ti) as main components,
Multi-layer structure consisting of several layers with different ruconium compositions
Or the composition of zirconium changes continuously.
Shaped piezoelectric material of perovskite type dielectric thin film with oblique composition structure
After forming a common electrode on the piezoelectric body,
With a piezoelectric element manufacturing method that removes all or part of the substrate
And the composition of Pb and Zr and Ti of the piezoelectric body.
Ratio: Pb / (Zr + Ti) is greater than 1 and 1.3 or less
It is characterized in that a lower piezoelectric body is formed .

According to the above method, the same effect as the first aspect can be obtained.
can get.

[0013] In the invention according to claim 4, the perro
Piezoelectric material of buskite type dielectric thin film is formed by sputtering method.
And the target composition of the sputtering method is PZT and P
a mixture of bO and PZT and PbO
Ratio: PbO / (PZT + PbO) is 0.05 to 0.3
5 is characterized.

According to the above method, a stable piezoelectric high pressure
It becomes possible to manufacture an electric element.

According to a fifth aspect of the present invention, the piezoelectric material
The thickness is 0.5 μm to 5 μm .

With the above configuration, the density can be increased by forming a thin film.
Therefore, a small-sized and high-resolution piezoelectric element can be manufactured.

According to a sixth aspect of the present invention, the individual electrode is formed on the (100) plane of the MgO substrate.

According to the above method, a stable piezoelectric element having high piezoelectricity can be manufactured.

According to a seventh aspect of the present invention, the individual electrode is made of platinum.

According to the above method, the same effect as that of the first aspect is obtained, and the workability of platinum is good, so that the individualization of the upper electrode is facilitated. In the invention according to claim 8,
A piezoelectric element according to any one of claims 1 to 3, a vibration plate for discharging ink, and a common ink chamber component forming a pressure chamber.

According to the above-mentioned method, the piezoelectric characteristics of the piezoelectric body are improved, the ink can be driven at a low voltage, the density can be increased by forming a thin film, and a small-sized and high-resolution head can be manufactured.

In the ninth aspect of the present invention, an individual electrode is formed on a substrate, and lead (Pb), zirconium (Zr), titanium (Tr) is formed on the individual electrode by sputtering.
i) whose main components are different in zirconium composition
Multi-layer structure consisting of two layers or zirconium composition
Perovskite-Type Induction of Gradient Composition Structure with Continuously Changing Gravity
After forming a piezoelectric body of an electric thin film , further forming a common electrode on the piezoelectric body, forming a diaphragm on the common electrode, removing all or a part of the substrate, and forming an ink on the diaphragm. A method for manufacturing an ink jet head for forming a pressure chamber for containing a liquid, comprising:
And the composition ratio with Ti: Pb / (Zr + Ti) is greater than 1
It is characterized by the fact that it is not more than 1.3 .

[0023] By the above method, Ru obtained the same effects as claim 8.

In the tenth aspect of the present invention, an individual electrode is formed on a substrate, and lead (Pb), zirconium (Zr), titanium (Tr) is formed on the individual electrode by sputtering.
i) whose main components are different in zirconium composition
Multi-layer structure consisting of two layers or zirconium composition
Perovskite-Type Induction of Gradient Composition Structure with Continuously Changing Gravity
A piezoelectric body of an electric thin film was formed, a common electrode was further formed on the piezoelectric body, a diaphragm was formed on the common electrode, and a pressure chamber for containing an ink liquid was formed on the diaphragm. after a manufacturing method of the ink-jet head to remove all or part of the substrate, and Pb of the piezoelectric,
Composition ratio with Zr and Ti: Pb / (Zr + Ti) is 1
And 1.3 or less .

[0025] By the above method, to obtain the same effect as claim 9, even more if the diaphragm is not rigid in thin, cheap ink-jet head without damaging the diaphragm
It can be manufactured by setting.

[0026] In the invention of claim 11, wherein, the sputtering
Whether the target composition in the method is a mixture of PZT and PbO
And the composition ratio of PZT and PbO: PbO / (P
ZT + PbO) is 0.05 to 0.35 .

According to the above method, a stable piezoelectric element having high piezoelectricity can be manufactured.

In the twelfth aspect of the present invention, the piezoelectric body
Has a thickness of 0.5 μm to 5 μm .

According to the above method, a piezoelectric element is formed by forming a thin film.
High-density, compact, high-resolution actuators
It can be manufactured and can be manufactured stably. Claim 1
In the invention described in Item 3, the individual electrode is made of magnesium oxide.
(MgO) Formed on (100) plane of substrate
And By the above method, stable piezoelectric element with high piezoelectricity
It becomes possible to make a child. According to the invention of claim 14,
In this case, the individual electrodes are made of platinum.
According to the above method, the same effect as that of the eighth aspect is obtained, and the workability of platinum is good, so that individualization as the upper electrode is facilitated.

[0030]

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

Embodiment 1 FIG. 1 is a cross-sectional view of an ink-jet head using a piezoelectric element according to Embodiment 1 of the present invention as viewed from the side.

In FIG. 1, an ink jet head using a piezoelectric element according to the present embodiment has a pressure chamber 6 for accommodating ink, a discharge port 8 for discharging ink, and a pressure communicating with the discharge port 8 to apply pressure to the pressure chamber 6. The piezoelectric element 4 includes a piezoelectric element 4 to be applied and a vibration plate 5 that vibrates with the piezoelectric element 4.
The piezoelectric element 4 includes a common electrode 3, a piezoelectric body 2, and an individual electrode 1, and is stacked on the diaphragm 5 in this order. Pressure chamber 6
Is formed from the vibration plate 5 and the common ink chamber component 7.
FIG. 1 is a cross-sectional view, in which a plurality of pressure chambers 6 separated by partition walls are arranged in a direction perpendicular to this cross section. Are lined up similarly.

The piezoelectric body 2 is a perovskite type PZT thin film, and the individual electrode 1 and the common electrode 3 are for applying a voltage to the piezoelectric body 2 and can be made of a conductive material, and in particular, at least partially. It is preferable to use platinum or gold.

The diaphragm 5 is for contracting and expanding the volume of the pressure chamber 6, and is made of nickel, chromium, or aluminum metal, or a metal oxide, silicon oxide, ceramics, or a polymer organic material. .

The common ink chamber component 7 supplies ink to the pressure chamber 5
And discharges ink from the discharge port 8, and is made of a metal material such as SUS, photosensitive glass or resin.

FIG. 2 is a diagram showing a manufacturing process of the ink jet head. The manufacturing process of the inkjet head will be described with reference to FIG. FIG. 2A: Substrate 20 made of MgO, Si, SUS, etc.
A platinum individual electrode 1 is formed thereon by rf sputtering. FIG. 2B: On the individual electrode 1 by rf sputtering,
The PZT thin film piezoelectric body 2 is formed. FIG. 2C: The common electrode 3 is formed on the piezoelectric body 2 by the rf sputtering method. At this stage, the piezoelectric element 4 is formed. FIG. 2D: The diaphragm 5 is formed along the adjacent surface of the common electrode 3. The method of forming the diaphragm 5 includes a sputtering method, a vacuum evaporation method, a plating method, a spin coating method, a joining method, and the like. FIG. 2E: The substrate 20 is removed by etching using an acidic solution. FIG. 2 (f): Finally, the diaphragm 5 and the simplified common ink chamber component 7 are joined.

Here, in FIG.
When the piezoelectric body 2 is manufactured by forming the individual electrode 1 made of platinum on the (100) plane of the MgO substrate 20 using MgO, it is possible to manufacture the stable piezoelectric element 4 having high piezoelectricity. . Although the rf sputtering method is used here, a piezoelectric thin film having good crystallinity can be formed by MOCVD or spin coating using a sol-gel solution.

Next, a manufacturing method for manufacturing an ink jet head even when the diaphragm is thin and has no rigidity will be described with reference to FIG. Steps (a) to (d) in FIG.
The steps up to this are the same as in the manufacturing method of FIG. In FIG. 3E, the common ink chamber component 7 is joined to the vibration plate 5. Then, FIG.
In (f), the substrate 20 is removed by etching using an acidic solution. With this manufacturing method, the rigidity is ensured by the common ink chamber component 7, so that even when the diaphragm 5 is thin and has no rigidity,
An ink jet head can be manufactured without damaging the diaphragm 5.

Next, the experimental results will be described. The structure of the produced inkjet head is as follows.
The thickness of the diaphragm 5 between the pressure chamber 6 and the piezoelectric element 4 is 2.9.
At μm, a chromium material was used. Also, common ink chamber parts 7
Used a SUS material having a thickness of 300 μm. As for the piezoelectric element 4, platinum having a thickness of 0.1 μm was used for both the individual electrode 1 and the common electrode 3. The method of manufacturing the ink jet head was the same as that of FIG. 3 because the diaphragm 5 was thin and had no rigidity. However,
The individual electrode 1 was formed on the (100) plane of the MgO substrate.

Using the above configuration, the thickness of the piezoelectric body 2 and P
A change in piezoelectric constant: d31 (unit: pC / N) representing piezoelectric characteristics when the composition ratio of b / (Zr + Ti) was changed was determined.

The results are shown in (Table 1).

[0042]

[Table 1]

As can be seen from Table 1, the piezoelectric constant is 10
A high value exceeding 0 is exhibited when (Condition 1) the composition ratio of Pb / (Zr + Ti) exceeds 1 and is 1.3 or less, and (Condition 2) when the film thickness of the piezoelectric material is 0. 5 μm or more and 5.0 μm
It is the following time. In addition, an ejection experiment was actually performed using ink, and it was confirmed that the ink was ejected favorably.

Therefore, since the piezoelectric element 4 manufactured under the above conditions 1 and 2 has high piezoelectric characteristics of the piezoelectric body 2, it can be driven at a low voltage as an actuator, and the sensitivity as a sensor can be improved. When the piezoelectric element 4 is used as an ink jet head, in addition to being able to be driven at a low voltage, a high density can be achieved by forming a thin film, and a small and high resolution can be achieved, so that a beautiful image is output. An inkjet head can be manufactured.

The sputtering method is used to manufacture the piezoelectric body 2, the target composition is a mixture of PZT and PbO, and the target composition ratio of PZT and PbO: PbO / (PZT + PbO) is 0. , 05-0.3
Setting to 5 is desirable because the thickness of the piezoelectric body 2 can be easily reduced to 10 μm or less and the composition ratio of Pb / (Zr + Ti) can be easily increased to more than 1 and 1.3 or less.

Although the common electrode 3 and the diaphragm 5 are separately provided here, the diaphragm 5 may also serve as the common electrode 3 when the diaphragm 5 is made of a conductive material. This simplifies the configuration.

(Embodiment 2) The difference from Embodiment 1 is that the piezoelectric body 2 has a multilayer structure composed of several layers having different compositions of zirconium.

FIG. 4 shows a two-layer structure. 4 is a perovskite-type PZT thin film containing Pb, Zr, and Ti as main components. The piezoelectric body 2-b is
Obtained by adding lanthanum to the PbTiO ₃ or PbTiO ₃ containing no of Zr, a thickness of about 0.01 [mu] m. As described above, first, the piezoelectric body 2-b is placed on the individual electrode 1.
Is formed, a high-quality piezoelectric thin film can be stably formed by forming the piezoelectric body 2-a thereon.

Although the piezoelectric body 2 has a two-layer structure here, the same effect can be obtained with a multilayer structure having three or more layers or a gradient composition structure in which the composition of zirconium changes continuously. .

[0050]

As described above, according to the present invention, lead (P)
b), mainly composed of zirconium (Zr) and titanium (Ti)
And some layers with different zirconium composition
Multi-layer structure, or continuous zirconium composition
Perovskite-Type Dielectric Thin Film with Gradient Composition
A is, the composition ratio of the Pb of the piezoelectric, and Zr and Ti: Pb / By (Zr + Ti) is to form a piezoelectric is larger and 1.3 or less than 1, the high-quality piezoelectric
Facilitates thin film formation and improves the piezoelectric properties of the piezoelectric body
However, the actuator can be driven at low voltage.
As a result, the sensitivity of the sensor can be improved, the density can be increased by forming a thin film , and the resolution can be reduced. Therefore, it is possible to manufacture an ink jet head that outputs a beautiful image.

[Brief description of the drawings]

Cross-sectional view of Louis inkjet head put to the first embodiment of the present invention; FIG

FIGS. 2A to 2F are manufacturing process diagrams of an inkjet head according to Embodiment 1 of the present invention.

FIGS. 3A to 3F are manufacturing process diagrams of an inkjet head according to Embodiment 1 of the present invention.

FIG. 4 is a cross-sectional view illustrating a configuration of an inkjet head according to Embodiment 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Individual electrode 2 Piezoelectric body 3 Common electrode 4 Piezoelectric element 5 Vibration plate 6 Pressure chamber 7 Common ink chamber part 8 Discharge port

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01L 41/22 (56) References JP-A-62-241870 (JP, A) JP-A-62-241823 (JP, A) JP-A-62-162623 (JP, A) JP-A-47-27396 (JP, A) JP-A-10-235864 (JP, A) JP-A-2-108545 (JP, A) JP-A-1-273373 ( JP, A) JP-A-10-286953 (JP, A) JP-A-8-116103 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 41/08

Claims (14)

(57) [Claims] 1. A common electrode and a lead (P) on the common electrode.
b), mainly composed of zirconium (Zr) and titanium (Ti)
And some layers with different zirconium composition
Multi-layer structure, or continuous zirconium composition
Perovskite-Type Dielectric Thin Film with Gradient Composition
The piezoelectric body, further wherein possess the individual electrode laminated on the piezoelectric body, and Pb of the piezoelectric, the composition ratio of Zr and Ti: Pb /
A piezoelectric element, wherein (Zr + Ti) is larger than 1 and 1.3 or less. 2. The piezoelectric element according to claim 1, wherein the thickness of the piezoelectric body is 0.5 μm to 5 μm. 3. An individual electrode is formed on a substrate.
Lead (Pb), zirconium (Zr), titanium
The main component is (Ti), and the composition of zirconium is different
Multi-layer structure consisting of several layers or zirconium
Perovskite with a graded composition structure whose composition changes continuously
After forming a piezoelectric body of a type dielectric thin film and further forming a common electrode on the piezoelectric body,
A method for manufacturing a piezoelectric element that removes all or a part
Thus, the composition ratio of Pb of the piezoelectric body to Zr and Ti: P
b / (Zr + Ti) is greater than 1 and 1.3 or less
Of manufacturing piezoelectric element characterized by forming a piezoelectric body
Law. 4. The piezoelectric film of the perovskite-type dielectric thin film.
A body is formed by a sputtering method, and a target of the sputtering method is formed.
The composition of the cut is from a mixture of PZT and lead oxide (PbO)
And the composition ratio of PZT and PbO: PbO / (PZO
4. The method according to claim 3 , wherein ( T + PbO) is 0.05 to 0.35 . 5. The method according to claim 1 , wherein the thickness of the piezoelectric body is 0.5 μm to 5 μm.
Method for manufacturing a piezoelectric element according to claim 3 or 4 further characterized in that there. 6. The individual electrode is made of magnesium oxide (MgO).
The method for manufacturing a piezoelectric element according to claim 3, wherein the piezoelectric element is formed on a (100) plane of a substrate. 7. The method according to claim 3, wherein the individual electrodes are made of platinum. 8. The method of claim 1 or 2 and the piezoelectric element described in the vibrating plate for ejecting ink, an ink jet head is characterized by comprising a common ink chamber parts forming a pressure chamber. 9. An individual electrode is formed on a substrate, and lead (Pb) and zirconium are formed on the individual electrode by a sputtering method.
(Zr), titanium (Ti) as a main component, zirconium
A multi-layer structure consisting of several layers with different compositions
Is a graded composition structure in which the composition of zirconium changes continuously
Forming a piezoelectric body of a perovskite type dielectric thin film , further forming a common electrode on the piezoelectric body, forming a diaphragm on the common electrode, removing all or a part of the substrate, the diaphragm A method for manufacturing an ink jet head for forming a pressure chamber for containing an ink liquid thereon,
Composition ratio of Pb of the piezoelectric body to Zr and Ti: Pb /
A method of manufacturing an ink jet head, wherein (Zr + Ti) is greater than 1 and 1.3 or less . 10. An individual electrode is formed on a substrate, and lead (Pb) and zirconium are formed on the individual electrode by a sputtering method.
(Zr), titanium (Ti) as a main component, zirconium
A multi-layer structure consisting of several layers with different compositions
Is a graded composition structure in which the composition of zirconium changes continuously
Pressure chamber for forming a perovskite-type dielectric thin film piezoelectric body , further forming a common electrode on the piezoelectric body, forming a diaphragm on the common electrode, and containing an ink liquid on the diaphragm Forming an ink jet head and removing all or part of the substrate, wherein the composition ratio of Pb of the piezoelectric body to Zr and Ti: P
b / (Zr + Ti) is greater than 1 and 1.3 or less
A method of manufacturing an ink jet head, characterized in that that. 11. The composition of a target for sputtering is PZ.
Consisting of a mixture of T and PbO, and PZT and PbO
Of PbO / (PZT + PbO) is 0.05 to
The method according to claim 9 , wherein the value is 0.35 . 12. The thickness of the piezoelectric body is 0.5 μm to 5 μm.
The method of manufacturing an ink jet head according to claim 9, wherein: 13. An individual electrode is made of magnesium oxide (Mg).
O) characterized by being formed on the (100) plane of the substrate
An inkjet according to any one of claims 9 to 12.
Head manufacturing method. 14. The individual electrode is made of platinum.
The ink jet according to any one of claims 9 to 13, wherein
Method of manufacturing a head.