JPH06206317A - Production of ink jet head - Google Patents

Abstract

PURPOSE:To provide an ink jet head production method for greatly reducing the head production cost and preventing inclusion of impurities in an electrode layer and a piezoelectric layer with respect to an ink jet head production method for making recording by delivering ink drops. CONSTITUTION:Firstly, a lower electrode layer 2 is printed on a surface of a vibrating plate 1, which is so disposed as to face a pressure chamber for applying a delivery pressure to ink liquid contained in the pressure chamber. After that, the lower electrode layer 2 is heated and calcined. Next, a piezoelectric layer 4 is printed on a surface of the lower electrode layer 2, thereafter being heated and calcined. Furthermore, an upper electrode layer 5 is printed on a surface of the piezoelectric layer 4, thereafter being heated and calcined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an ink jet head for recording by ejecting ink droplets.

The ink jet recording system has features such as a simple structure, easy colorization, and no noise, and is expected as the mainstream of future recording systems.

[0003]

2. Description of the Related Art In order to eject ink droplets from an ink jet head, a vibrating plate provided facing the pressure chamber is vibrated to apply an ejection pressure to the ink in the pressure chamber.

Generally, a piezoelectric element vibrates the diaphragm, and the piezoelectric element is provided in close contact with the surface of the diaphragm corresponding to the position of the pressure chamber. In the past, such a piezoelectric element was formed in a size corresponding to a pressure chamber by sandwiching a piezoelectric body with electrodes in a sandwich shape, and was bonded to the surface of each vibration plate one by one.

[0005]

However, since it is necessary to attach the same number of piezoelectric elements to the ink jet head as the number of ink discharge nozzles, it is very time-consuming to attach each piezoelectric element to the diaphragm. , Increases the manufacturing cost of the head.

Therefore, it is conceivable that the lower electrode layer, the piezoelectric layer, and the upper electrode layer are sequentially formed by printing on the surface of the vibration plate, and then heated and baked to directly form the piezoelectric element on the vibration plate.

However, when the piezoelectric layer and the electrode layer are heated and fired at the same time, mass transfer occurs between the piezoelectric layer and the electrode layer, and impurities are mixed into each layer to impair the respective characteristics. Will end up.

Therefore, an object of the present invention is to provide a method for manufacturing an ink jet head which can significantly reduce the manufacturing cost of the head and which does not cause impurities to be mixed in the electrode layer and the piezoelectric layer.

[0009]

In order to achieve the above-mentioned object, the method of manufacturing an ink jet head of the present invention is shown in FIG.
As shown in FIG. 1, first, the lower electrode layer 2 is printed on the surface of the vibration plate 1 provided facing the pressure chamber 3 in order to apply the discharge pressure to the ink liquid contained in the pressure chamber 3,
After heating and baking, printing the piezoelectric layer 4 on the surface of the lower electrode layer 2, heating and baking, printing the upper electrode layer 5 on the surface of the piezoelectric layer 4, and then heating , Firing.

The heating and firing temperature of the upper electrode layer 5 is not higher than the heating and firing temperature of the piezoelectric layer 4, and the heating and firing temperature of the piezoelectric layer 4 is not higher than the heating and firing temperature of the lower electrode layer 2. Good to have.

[0011]

The lower electrode layer 2 is first printed and fired on the surface of the vibration plate 1, and then the piezoelectric layer 4 is printed and fired on the surface, and the upper electrode layer 5 is applied on the surface of the piezoelectric layer 4 after firing. Is printed and fired.

In this way, for each layer, the next layer is printed and fired after printing and firing, so that mass transfer between the layers can be suppressed. Then, by setting the heating and firing temperature of the layer to be printed and fired later to be equal to or lower than the heating and firing temperature of the layer to be printed and fired first, the mass transfer between the respective layers can be more completely suppressed.

[0013]

Embodiments will be described with reference to the drawings. Figure 2
1 schematically shows an apparatus for screen-printing an electrode layer and a piezoelectric layer on the vibration plate 1, 51 is a screen on which a print pattern is formed, and 52 is a squeegee.

As the vibrating plate 1, a silicon single crystal wafer is used here, and it is not melted by heat treatment at a high temperature up to about 1200 ° C. and no distortion is generated. In addition,
An aluminum oxide plate or the like may be used as the vibration plate.

Here, first, the lower electrode layer 2 is uniformly screen-printed on a wide area of the surface of the diaphragm 1. FIG. 3 shows such a state. For example, a conductive paste prepared by mixing silver and palladium powder, a binder for binding them and an organic solvent is applied onto the screen 51, and is moved while pressing the squeegee 52. As a result, the lower electrode layer 2 is printed on the surface of the diaphragm 1.

Then, after drying this, it is heated and baked in the atmosphere at 1000 ° C. for 2 hours in an electric furnace. As a result of observing the surface, the pores (air bubbles) in the electrode layer 2 were observed by heating at a temperature of 1000 to 1100 ° C. for 1 hour or more.
Is reduced and mass transfer is suppressed.

A platinum paste may be used as the conductive paste, and in this case, the firing temperature is 1200 to 140 depending on the melting point of platinum higher than silver and palladium.
It is recommended to set it to 0 ° C.

Next, as shown in FIG. 4, the piezoelectric layer 4 is formed on the surface of the lower electrode layer 2 by using a screen 54 on which a print pattern matching the position and shape of the pressure chamber 3 described later is formed. Screen print.

As shown in FIG. 5, one diaphragm 1
Is a size for forming a large number of inkjet heads 10 together, and one of the inkjet heads 10 is
As shown in FIG. 6, which shows a portion A of FIG.
Is printed.

As the piezoelectric paste, for example, 0.5P
A mixture of NN-0.35PT-0.15PZ piezoelectric fine powder, ethyl cellulose as a binder for binding these powders, and terpineol as an organic solvent in a weight ratio of, for example, 100: 1/20 is used. . However, a material containing a PZT system and other third component may be used.

Then, after the piezoelectric layer 4 is printed and dried, it is heated in an atmosphere at 1000 ° C. for 2 hours in an electric furnace,
Bake. In this case, at a high temperature of 900 ° C. or higher, the piezoelectric layer 4 becomes dense and does not become brittle, and the densification is promoted by the firing time of 2 hours.

Next, as shown in FIG. 7, an upper electrode layer 5 is screen-printed on the surface of each piezoelectric layer 4 using the same conductive paste as that for the lower electrode layer 2, and after drying, it is dried in the atmosphere by an electric furnace. Medium, heated and baked at 1000 ° C. for 2 hours. However, for the upper electrode layer 5, gold or other conductive paste capable of firing at a low temperature may be used.

As a result of examination by X-ray diffraction (XRD), in the integrated firing of the electrode layer and the piezoelectric layer, as shown in FIG. 9, mass transfer between layers produces a piechlore phase having no piezoelectricity. On the other hand, in the sample of this example, as shown in FIG. 10, it was confirmed that the inter-layer mass transfer was suppressed and the piezoelectric perovskite phase was generated.

In FIG. 8, the vibrating plate 1 on which the electrode layers 2 and 5 and the piezoelectric layer 4 are directly printed and fired in this way is communicated with the ink flow path 6 to form the substrate 7 in which the pressure chamber 3 is formed. It shows a state of being joined to. 8 is a nozzle hole.

However, the vibration plate 1 and the substrate 7 may be bonded to each other before the electrode layers 2 and 5 and the piezoelectric layer 4 are fired.
The pressure chamber 3 and the ink flow path 6 may be formed integrally with the vibration plate 1.

In the ink jet head thus formed, the piezoelectric layer 4 is formed by filling the pressure chamber 3 with the ink liquid from the ink flow path 6 and applying a voltage between the upper and lower electrodes 2 and 5. Due to the deformation, the vibrating plate 1 vibrates and an ejection pressure is applied to the ink liquid in the pressure chamber 3, and the ink in the pressure chamber 3 is ejected as an ink droplet from the nozzle hole 8 for recording.

In the above embodiment, each layer 2,
Although the firing temperatures of 4 and 5 are set to 1000 ° C., for example, the firing temperature of the lower electrode layer 2 is 1100 ° C. and the piezoelectric layer 4 is
And the upper electrode layer 5 has a firing temperature of 1000.degree.
By setting the firing temperature of the portion to be heated and fired later to be lower than the firing temperature of the already fired portion so as to be 50 ° C., it is possible to more completely suppress the mass transfer between the layers,
As shown in FIG. 11, more perovskite phase is generated.

[0028]

According to the method of manufacturing an ink jet head of the present invention, since the piezoelectric layer is directly formed on the surface of the vibration plate by printing and firing, the number of assembling steps can be reduced and a significant cost reduction can be achieved. Moreover, for each layer of the electrode layer and the piezoelectric layer, the next layer is printed and fired after printing and firing, so that mass transfer between each layer is suppressed, impurities are not mixed in each layer, and the characteristics of each layer are impaired. It has an excellent effect.

By setting the firing temperature of the portion to be heated and fired later to be equal to or lower than the firing temperature of the already fired portion, the mass transfer between the layers can be suppressed more completely.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a perspective view showing a manufacturing process of an example.

FIG. 3 is a side view showing the manufacturing process of the example.

FIG. 4 is a side view showing the manufacturing process of the example.

FIG. 5 is a plan view of the diaphragm of the embodiment.

FIG. 6 is a partially enlarged plan view of the diaphragm of the embodiment.

FIG. 7 is a side view showing the manufacturing process of the example.

FIG. 8 is a partial side sectional view of the inkjet head of the embodiment.

FIG. 9 is an X-ray diffraction characteristic diagram when an electrode layer and a piezoelectric layer are integrally fired.

FIG. 10 is an X-ray diffraction characteristic diagram according to an example.

FIG. 11 is an X-ray diffraction characteristic diagram according to an example.

[Explanation of symbols]

 1 Vibration Plate 2 Lower Electrode Layer 3 Pressure Chamber 4 Piezoelectric Layer 5 Upper Electrode Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Nakazawa 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (2)

[Claims] 1. A lower electrode layer (1) is first formed on the surface of a vibration plate (1) provided facing the pressure chamber (3) in order to apply a discharge pressure to the ink liquid contained in the pressure chamber (3). After printing 2), heating and firing are performed. Next, after printing the piezoelectric layer (4) on the surface of the lower electrode layer (2), heating and firing are performed. On the surface, the upper electrode layer (5)
A method for manufacturing an inkjet head, which comprises heating and baking after printing. 2. The heating and firing temperature of the upper electrode layer (5) is not higher than the heating and firing temperature of the piezoelectric layer (4), and the heating and firing temperature of the piezoelectric layer (4) is the lower electrode layer ( The method for producing an inkjet head according to claim 1, wherein the heating temperature is 2) or less.