JP2913862B2 - Piezoelectric actuator element for pulse droplet deposition device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a piezoelectric actuator device and its manufacturing method of pulse droplet deposition apparatus, producing a pulse drop inkjet printer piezoelectric actuator element head utilizing shear deformation of the piezoelectric element and more specifically It is about the method.

[0002]

2. Description of the Related Art Conventionally, a structure of a piezoelectric actuator element for a pulse ink jet printer head utilizing a shear deformation of a piezoelectric element and a method of manufacturing the piezoelectric actuator element are disclosed in Japanese Patent Application Laid-Open No. Sho 63/1988.
No. 247051. FIG. 6 shows a configuration example of the pulse droplet deposition device and the piezoelectric actuator element. In this pulse droplet applying apparatus, a driving electrode is formed on a droplet ejecting nozzle plate 42 having a large number of ink ejecting holes 41, a large number of ink grooves 43 (pressure chambers) to which the nozzle plate 42 is connected, and side wall surfaces 44. And a liquid supply mechanism (not shown) for replenishing ink.

When an electric field is applied to the drive electrode, the above-described pulse droplet deposition apparatus causes the piezoelectric material to undergo shear deformation, and the ink grooves 43 are formed.
Causes a change in volume. As a result, the ink grooves 43
The inside liquid pressure changes, and ink is ejected from the ejection holes of the nozzle plate 41. As a method of manufacturing a piezoelectric actuator element having a plurality of ink grooves 43, a method of forming ink grooves using a diamond cutter blade, a laser, or the like on a piezoelectric material plate or a piezoelectric material plate bonded to a substrate is used. A method was presented. When such a piezoelectric actuator element is applied as an actuator of an ink jet printer head, it is necessary to form a large number of ink grooves with high precision in order to improve the degree of integration of ink jet nozzles. Further, in order to effectively utilize the shear deformation of the piezoelectric material, it was necessary to make the height dimension larger than the width dimension of the piezoelectric material wall. (In other words, it was necessary to form a deep ink groove.)

[0004]

However, in the above-described method of forming ink grooves using a diamond cutter blade, a laser, or the like, when deep ink grooves effective for shear deformation of a piezoelectric material are processed, It is extremely inefficient as a manufacturing method, the yield by processing is poor, and it is difficult to satisfy the requirements in terms of dimensions and pitch accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a high degree of integration of ink grooves and a piezoelectric material for an ink jet printer head having a piezoelectric material wall shape capable of effectively utilizing the shear deformation of the piezoelectric material. It is an object to present a method for manufacturing an actuator element at low cost.

[0006]

In order to achieve this object, a manufacturing method according to the present invention is directed to a pulse droplet deposition apparatus comprising a plurality of ink grooves, a piezoelectric material, and a drive electrode for applying an electric field to the piezoelectric material. at a manufacturing method of use piezoelectric actuator element, the resin material and the piezoelectric material is molded out morphism using the composite material is the main component in a number of walls and the walls made of a composite material
Forming a piezoelectric actuator element having a plurality of ink channels, a step of polarizing the piezoelectric actuator element, on both sides of each wall, conductive perpendicular to the polarization direction
Forming a drive electrode for forming a field .

Preferably, drive electrodes on both sides of each wall
Is formed after the polarization step.

More preferably, the piezoelectric actuator
Process of degreasing the resin component from the data element and sintering the piezoelectric material
including.

Further , the present invention provides a method for manufacturing a plurality of ink grooves and piezoelectric materials.
Material and a drive electrode for applying an electric field to the piezoelectric material.
Piezo actuator element for pulse drop deposition device
Te, before Symbol piezoelectric actuator elements, the resin material and the piezoelectric material
Between composite walls, where the main component is the composite material
A plurality of ink grooves, wherein the driving electrode is formed of the composite material
Formed on both sides of a wall made of steel, with a higher Young's modulus than the wall
It is characterized by the fact that it is made of a material.

[0010]

According to the manufacturing method of the present invention, a composite piezoelectric material composed of a resin material having excellent moldability and a piezoelectric material having a large piezoelectric constant is used as a material for forming the piezoelectric actuator element, thereby having a practical level of piezoelectric characteristics. In addition, a piezoelectric material having excellent moldability can be used as a material for a piezoelectric actuator element. Since a high-precision injection molding method that effectively utilizes the moldability of the resin material having excellent moldability can be applied, a plurality of ink grooves can be formed with high dimensional and pitch accuracy without using machining means such as machining or laser machining. Can be formed. Further, the use of the injection molding method can greatly reduce the manufacturing time.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In the present embodiment, polycarbonate, which is an engineering plastic, was selected as the resin material of the composite piezoelectric material, focusing on moldability, heat resistance, and strength. Other engineering plastic materials such as polyacetal and nylon can be selected as needed. Large piezoelectric constant d ₁₅ is the piezoelectric material, chose a low electric field intensity can be polarized piezoelectric ceramic material (Tokin Ltd. N-10). The sintered body of the piezoelectric ceramic was pulverized using a pulverizer to obtain a powder having an average particle size of about 6 μm. After 70 vol% of the piezoelectric ceramic powder and 30 vol% of the total of polycarbonate, plasticizer and lubricant were dry-mixed, the mixture was heated and kneaded using a pressure kneader and pelletized using a pelletizer. Injection molding was performed using the pelletized composite piezoelectric material. FIG. 1 schematically shows an in-line screw type injection molding machine. The injection molding machine includes a heater 12 for heating, a screw 13, a cylinder 14, a hydraulic motor 15, and a hydraulic cylinder 16, and the pelletized composite piezoelectric material 2 supplied from the hopper 17 is supplied to the nozzle 11. Melts. When the screw 13 rotates and moves, the molten composite piezoelectric material is injected from the nozzle 11 into the cavity formed by the injection molds 1a and 1b by the set injection pressure. FIG. 2 shows the piezoelectric actuator element 3 for an ink jet printer head molded in a cavity formed by the injection molds 1a and 1b. FIG. 3 shows a state where the piezoelectric actuator element 3 for an ink jet printer head molded in the cavity formed by the injection molds 1a and 1b is released from the injection molds 1a and 1b. Molded piezoelectric actuator element 3 for inkjet printer head
Has a number of parallel walls of composite piezoelectric material and a number of parallel ink channels (ink channels, pressure chambers) formed between the parallel walls. FIG. 4 shows a step of polarizing the piezoelectric actuator element 3. The formed piezoelectric actuator element 3 includes a polarizing jig 21a,
A DC electric field is applied at 21b. When an electric field as shown in FIG. 4 is applied, the polarization direction 4 of the piezoelectric actuator element 3 becomes the thickness direction. FIG. 5 shows a piezoelectric actuator element for an ink jet printer head on which a drive electrode and a protective film are formed. A drive electrode 7 made of nickel is formed by sputtering on the side surface of a plurality of parallelly arranged composite piezoelectric material walls 5 of the polarized piezoelectric actuator element 3.
Thereafter, a protective film of alumina 8 (other ceramics having a large Young's modulus and high corrosion resistance may be formed) is formed on the side surface of the wall 5 of the composite piezoelectric material and the bottom surface of the ink groove 6. The thus obtained piezoelectric actuator element for an ink jet printer head formed of the composite piezoelectric material of the present example has a width of 0.2 mm within an outer dimension of 16 × 16 × 1 mm.
A wall composed of 49 composite piezoelectric materials having a height of 0.5 mm and a length of 16 mm arranged in parallel and a wall of the composite piezoelectric material adjacent thereto are formed in parallel with a width of 0.1 mm, a depth of 0.5 mm and a length of 16 mm. It has 48 ink grooves. When an electric field is applied to the drive electrode formed on the side surface of the wall of the composite piezoelectric material, the wall of the composite piezoelectric material undergoes shear deformation because the direction of the applied electric field is orthogonal to the polarization direction. Due to this deformation, the volume of the ink groove changes, and the liquid pressure of the ink in the ink groove changes.
The ink groove operates as a kind of pressure chamber, and ink ejection occurs.

When a composite piezoelectric material of a resin and a piezoelectric ceramic is used as the piezoelectric material, the compliance of the piezoelectric material wall may be increased, and matching with the compliance of the ink used may be reduced. As a method for solving this problem, in this embodiment, nickel having a higher Young's modulus than the composite piezoelectric material is used as a drive electrode on the side surface of the wall of the composite piezoelectric material, and an alumina ceramic layer having a higher Young's modulus is provided as a protective film. Apparently, the wall compliance of the composite piezoelectric material was reduced. Another problem when the composite piezoelectric material is used is a problem of the corrosion resistance of the resin material used to the ink. Although engineering plastics have some degree of corrosion resistance, when applied as piezoelectric actuator elements for ink jet printer heads, they generate heat when driven. Under these conditions, concerns about the corrosion resistance of engineering plastics remain. Therefore, a protective film made of alumina ceramic was provided not only on the side surface of the wall of the composite piezoelectric material but also on the bottom surface of the ink groove. Another application example of the manufacturing process of the present invention will be described below. Although the piezoelectric actuator element of the above embodiment is made of a resin material and a piezoelectric ceramic material, the piezoelectric actuator element can be made of a piezoelectric ceramic sintered body simply by applying the manufacturing process of the present invention. it can. The method uses a composite material of a resin material having excellent moldability and a piezoelectric ceramic powder as a raw material for molding in the same manner as in the above embodiment, and obtains an injection molded body having a plurality of ink grooves formed by a high precision injection molding method. . Thereafter, only the resin component in the injection molded body is degreased by heat treatment, and the obtained degreased body is sintered under the sintering conditions of a piezoelectric ceramic powder material using as a raw material. By using such a manufacturing process, a piezoelectric actuator element for an ink jet printer head having a plurality of ink grooves formed of a piezoelectric ceramic sintered body can be manufactured. As another application example, there is a method of manufacturing a piezoelectric actuator element using a polymer piezoelectric material represented by polyvinylidene fluoride, a copolymer of vinylidene fluoride and ethylene trifluoride, or the like. Also in this example, the manufacturing process of the above embodiment can be applied, and a piezoelectric actuator element for an ink jet printer head having a plurality of ink grooves formed of a piezoelectric polymer material can be manufactured.

[0014]

As is apparent from the above description, many
The piezoelectric actuator element for a pulse droplet deposition apparatus having a shape having a number of ink grooves is manufactured using a composite material in which a resin material excellent in moldability and a piezoelectric material are main components in the manufacturing process of the present invention, and the moldability of the resin material is improved. By using a high-precision molding method (such as a high-precision injection molding method) that utilizes, a plurality of ink grooves can be formed with high precision and high integration at low cost without performing groove processing by machining or laser processing. Mass production of the manufactured piezoelectric actuator element for the pulse droplet deposition apparatus.

Further , a composite material of a resin material and a piezoelectric material is used.
Problems with high wall compliance
The composite wall,
The problem can be solved by forming a drive electrode with high Young's modulus
Can be .

[Brief description of the drawings]

FIG. 1 is a view showing an injection molding process of the present embodiment.

FIG. 2 is a view showing an injection molding process of the present embodiment.

FIG. 3 is a diagram showing an injection molding process of the present embodiment.

FIG. 4 is a view showing a polarization step of the present embodiment.

FIG. 5 is a diagram illustrating a driving electrode and a protective film forming step of the present embodiment.

FIG. 6 is a configuration diagram of a pulse droplet deposition device and a piezoelectric actuator element.

[Explanation of symbols]

 2 Composite material 3 Piezoelectric actuator element 6 Ink groove 7 Drive electrode

Claims (5)

(57) [Claims] In a method of manufacturing a piezoelectric actuator element for a pulse droplet deposition apparatus, comprising a plurality of ink grooves, a piezoelectric material, and a drive electrode for applying an electric field to the piezoelectric material, a resin material and a piezoelectric material are mainly used. using the composite material which is a component
Forming a piezoelectric actuator element having morphism-molded to a composite material made of a number of walls and a large number of <br/> ink grooves in its walls, and a step of polarizing the piezoelectric actuator element, wherein each wall An electric field perpendicular to the polarization direction is formed on both sides.
Forming a drive electrode for forming the piezoelectric actuator element for a pulse droplet deposition apparatus. 2. The drive electrodes on both sides of each of the walls are polarized.
2. The method according to claim 1, wherein the forming is performed after the step.
A method for manufacturing a piezoelectric actuator element for a loose drop attaching device . 3. The drive electrode of claim 1, wherein the drive electrode comprises a wall of the composite material.
Characterized by a material having a higher Young's modulus than
The piezoelectric actuator element for a pulse droplet deposition device according to claim 2
Child manufacturing method . 4. The method according to claim 1, wherein the piezoelectric actuator element is made of a resin.
Degreasing and sintering of piezoelectric material
The piezoelectric actuator for a pulse droplet deposition device according to claim 1,
A method for manufacturing an eta element . 5. A plurality of ink grooves, a piezoelectric material, and the piezoelectric material.
With a pulse droplet consisting of a drive electrode for applying an electric field to the
In the piezoelectric actuator element for a mounting device, the piezoelectric actuator element is made of a resin material and a piezoelectric material.
Numerous walls made of composite material, the main component and numerous between the walls
The drive electrodes are formed on both side surfaces of the composite material wall.
It is, especially in that it consists of material Young's modulus higher than that wall
A piezoelectric actuator element for a pulse droplet deposition device .