JPH0768754A - Driving electrode forming method for ink jet device - Google Patents

Abstract

PURPOSE:To provide a method for forming a driving electrode of an ink jet device in which a driving electrode can be easily formed in a short time. CONSTITUTION:Inert gas 6 such as Ar, He, etc., is introduced to an ultrafine particle generating chamber 5 being in vacuum to evacuate in low vacuum (1-400Torr) in the chamber 5. Al is filled in an alumina crucible 7 installed in the chamber 5 and a heater 8 is wound, and the crucible 7 is heated by energizing to evaporate the Al. The evaporated Al vapor 9 is collided with the gas 6, cooled, and aggregated to generate ultrafine particles 10. The particles 10 are injected from a plurality of fine-diameter nozzles provided on a nozzle plate 13 due to a differential pressure between a film forming chamber 12 and the chamber 5 to form an Al thin film to become a driving electrode on a half region from an opening of a sidewall.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming drive electrodes for an ink jet device.

[0002]

2. Description of the Related Art Recently, a printer head using a piezoelectric ink jet has been proposed. This is to change the volume of the ink chamber by the dimensional displacement of the piezoelectric actuator so that the ink in the ink chamber is ejected when the volume decreases and the ink is introduced into the ink chamber when the volume increases. Then, a large number of such ink ejecting devices are arranged close to each other, and ink is ejected from the ink ejecting device at a predetermined position to form a desired character or image.

An example of such an ink ejecting device is shown in FIG. This will be specifically described below with reference to FIG. 5, which is a partial cross-sectional view of the array 41. The piezoelectric ceramic plate 1 having a plurality of side walls 3 and polarized in the direction of arrow 21 is joined to the lid 18. By doing so, a large number of parallel ink chambers 16 having a space between each other in the lateral direction are formed. The ink chamber 16 has a long and narrow rectangular cross section, and the side wall 3 extends over the entire length of the ink chamber 16. A drive electrode 4 for applying a drive voltage is formed in the lower half (or upper half) region of the surface of the side wall 3. The ink is a conductive material, or
The drive electrode 4 is used to improve reliability and durability.
A protective film (not shown) is produced from above.

The ink ejecting device 17 includes an ink chamber 16 and
An ejection port (not shown) communicating with one end of the ink chamber 16
And an ink supply portion (not shown) communicating with the other end of the ink chamber 16, and a piezoelectrically deformable side wall 3 forming the ink chamber 16.

The array 41 is provided with the electrical circuit shown in FIG. In this electric circuit, the drive electrodes 4a to 4h are separately connected to the LSI chip 31, and the clock line 32, the data line 33, the voltage line 34, and the ground line 35 are also connected to the LSI chip 31. The ink chambers 16a to 16c are divided into first and second groups which are not adjacent to each other, and are set to L by continuous clock pulses supplied from the clock line 32.
The SI chip 31 continuously drives the first and second groups. With the multi-bit word format data appearing on the data lines 33, the LSI chip 31 determines which of the ink chambers 16a-16c of each group should be activated,
The voltage V on the voltage line 34 is applied to the drive electrodes 4 of the ink chambers 16 of the selected group. This selected ink chamber 1
Both side walls 3 of 6 are deformed by the piezoelectric effect. At this time, the drive electrodes 4 of the ink chambers 16 of the same group which are not operated and the drive electrodes 4 of all the ink chambers 16 belonging to another group are grounded.

FIG. 6 shows a case where the channel 17b is selected according to predetermined print data.
The voltage V of the voltage line 34 is applied to the drive electrodes 4d and 4e in 6b.
Is applied to the other drive electrodes 4a, 4b, 4c, 4f, 4
g and 4h are grounded. Then, driving electric fields 25 and 26, which are orthogonal to the polarization direction, are generated in the portions of the side walls 3b and 3c where the driving electrodes 4 are formed, so that the side walls 3b and 3c are formed into a dogleg shape due to the deformation of the piezoelectric thickness sliding effect. 16b
Deforms toward the outside. Therefore, as the volume of the ink chamber 16b increases, the ink is replenished from the ink supply unit (not shown). In addition, the application of voltage is cut off and the side walls 3b,
When 3c returns to the original position, the volume of the ink chamber 16b decreases and the ink in the ink chamber 16b ejects the ink (not shown).
Is jetted through. Incidentally, for example, another channel 17c
When is selected, the side walls 3c and 3d are deformed and the ink in the ink chamber 16c is ejected.

Conventionally, the drive electrode 4 is, for example, disclosed in Japanese Patent Laid-Open No. 2-1.
It is formed by the method disclosed in Japanese Patent No. 50355. According to the method described in this publication, first, a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity is subjected to a polarization treatment in a polarization direction, and the diamond cutting disks are rotated or parallel to each other by a laser or the like. The piezoelectric ceramic plate 1 for forming the ink chamber 16 is manufactured by cutting a plurality of grooves 2 (FIG. 7) having the same width. Next, the drive electrode 4 is formed on the side wall 3 by a vacuum vapor deposition method. At this time, as shown in FIG. 7, by inclining the piezoelectric ceramic plate 1 with respect to the evaporation source 19 by an angle ψ, the side wall 3 has a shadow effect so that the drive electrode is formed only in a necessary region on the side of the opening of the side wall 3. 4 is formed, and then the conductive thin film on the crown 15 of the side wall 3 is removed to form the drive electrode 4.

[0008]

However, in the conventional method of forming drive electrodes on the side wall 3 of the ink ejecting apparatus 17 of this type as described in the above publication,
Vacuum deposition is performed using the shadow effect of the side wall 3, but the metal particles evaporated from the evaporation source 19 fly radially, so the distance between the evaporation source 19 and the side wall 3 forming the drive electrode 4 is increased. Since it is necessary to take advantage of the straightness of the vapor-deposited metal to vaporize only part of the metal particles vaporized from the vaporization source 19 on the side wall 3, there is a problem that the formation speed of the drive electrode 4 is slow. It was

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a method of forming a drive electrode for an ink ejecting apparatus which can easily form a drive electrode in a short time.

[0010]

In order to achieve this object, according to claim 1 of the present invention, at least a part is a piezoelectric portion, a side wall forming an ink chamber, and a drive electrode formed on the piezoelectric portion. In the method of forming a drive electrode for an ink ejecting apparatus, which includes: and deforms the side wall by applying a voltage to the drive electrode to eject ink from the ink chamber, conductive ultrafine particles are generated in the ultrafine particle generation chamber. The first step,
In the film forming chamber, the conductive ultrafine particles are sprayed onto the side wall by a differential pressure between the ultrafine particle generating chamber and the film forming chamber to form the drive electrode.

In the second aspect, the conductive ultrafine particles are A
It is characterized in that a metal such as 1, Ni, Cr or the like, or a conductive material such as a NiCr alloy is evaporated, and the vapor is cooled and agglomerated by colliding with an inert gas such as Ar or He to be generated. .

According to a third aspect of the present invention, the pressure difference between the ultrafine particle generating chamber and the film forming chamber is 3 Kg / cm ² or more.

In claim 4, following the second step,
A third step of generating insulating ultrafine particles in the ultrafine particle generating chamber, and a fourth step of spraying the insulating ultrafine particles to the drive electrode to form a protective film of the drive electrode in the film forming chamber. It consists of and.

[0014]

In the method of forming a drive electrode for an ink jet device of the present invention having the above structure, conductive ultrafine particles are produced in the ultrafine particle producing chamber in the first step, and in the second step,
In the film forming chamber, the conductive ultrafine particles are sprayed onto the side wall by the pressure difference between the ultrafine particle generating chamber and the film forming chamber to form the drive electrode.

[0015]

Embodiments of the present invention will now be described with reference to FIGS.
This will be described in detail with reference to FIG. It should be noted that the same parts as those of the conventional example described above and the equivalent parts will be described with the same reference numerals.

First, as shown in FIG. 1, the piezoelectric ceramic plate 1 is a lead zirconate titanate (P) having ferroelectricity.
It is a plate made of a ZT) -based ceramic material and polarized in the direction of arrow 21 and having a thickness of about 1 mm, and a plurality of parallel grooves 2 are formed by rotation of a diamond cutting disk or laser. The groove 2 has, for example, a rectangular cross section with a width of 90 μm and a height of 400 μm, and extends in a direction perpendicular to the paper surface with a length of about 10 mm. The pitch of the grooves 2 is a desired printing resolution, for example 170 μm. Next, using the device shown in FIG.
The drive electrode 4 is formed in a half area from the opening. Then, after forming a protective film (not shown) on the drive electrodes 4 as required, a lid 18 (FIG. 5) is adhered to the opening side of the groove 2 of the piezoelectric ceramic plate 1 so that they are laterally aligned with each other. A number of parallel ink chambers 16 (FIG. 5) are formed at intervals.

An example will be described below in which an Al film is coated as the drive electrode 4 on a region half the opening of the side wall 3.

As shown in FIG. 2, by introducing an inert gas 6 such as Ar or He into the ultrafine particle producing chamber 5 which has been evacuated by a vacuum pump, the inside of the ultrafine particle producing chamber 5 has a low vacuum (1 to 400 Torr). ). The alumina (Al ₂ O ₃ ) crucible 7 installed in the ultrafine particle generation chamber 5 has a particle size of 2 to 2
Put 5 mm Al particles. A heater 8 is wound around the alumina crucible 7, and the heater 8 is energized to heat the alumina crucible 7 to melt and evaporate the Al contained therein.

The evaporated Al vapor 9 collides with an inert gas 6 such as Ar and He introduced into the ultrafine particle generation chamber 5, is cooled and aggregated, and has a high purity of ultrafine particles having a particle size of 10 to 1000 angstroms. Generate 10. The ultrafine particles 10
Has a lower pressure than the ultrafine particle generation chamber 5 due to the transfer pipe 11,
That is, the film is introduced into the high-vacuum (about 10 ⁻⁴ to 10 ⁻⁷ Torr) film forming chamber 12, and due to the pressure difference between the film forming chamber 12 and the ultrafine particle forming chamber 5, the nozzle plate 13 as shown in FIG. A plurality of small-diameter nozzles 14 having an angle α are sprayed at high speed to form an Al thin film to be the drive electrode 4 in a half region from the opening of the side wall 3.

When forming this thin film, as shown in FIG. 4, the nozzle plate 13 is brought into contact with the crown 15 of the side wall 3, the diameter of the nozzle 14 is made equal to the width of the groove 90 μm, and the angle α is set to 24.2 °. Then, the Al thin film, that is, the drive electrode 4 can be formed only in a half region from the opening side of the side wall 3.
When the drive electrode 4 is formed in this manner, the top portion 1 of the side wall 3 is formed.
The Al ultra-fine particles 10 which is a conductive material do not adhere to 5 and the thin film removing step of the crown 15 as in the conventional case is not required. Further, if the pressure difference between the film forming chamber 12 and the ultrafine particle generating chamber 5 is 3 Kg / cm ² or more, the adhesive force is 500 Kg /
A good thin film having a cm ² or more and a density of 95% or more can be formed.

Further, when a protective film is required, after the drive electrode 4 is formed, O is added to the ultrafine particle generation chamber 5.
₂ and an inert gas 6 such as Ar or He: 1: 100 to 30:
By introducing the mixed gas at a pressure ratio of 100,
Al vapor 9 and O ₂ are caused to collide with each other to cause an oxidation reaction,
Ultrafine particles 10 of Al ₂ O ₃ are produced. Al ₂ generated
The O ₃ ultrafine particles 10 are fed to the film forming chamber 12 by the carrier tube 11 and sprayed from the nozzle 13 onto the side wall 3 on which the drive electrode 4 is formed to form an Al ₂ O ₃ film, and the Al ₂ O ₃ film is formed. It may be used as a protective film.

As described above, in this embodiment, the ultrafine particles 10 produced in the ultrafine particle producing chamber 5 are blown to the side wall 3 due to the pressure difference between the film forming chamber 12 and the ultrafine particle producing chamber 5. The ultrafine particles 10 are jetted at a high speed to form an Al thin film to be the drive electrode 4 on the side wall 3 in a short time.

In this embodiment, Al is used as the material of the drive electrode 4.
However, in the present invention, the drive electrode 4 can be formed without any problem as long as it is a conductive material such as a metal such as Ni or Cr or a NiCr alloy, and is appropriately selected depending on the corrosion resistance, the resistivity, the adhesion, and the like. Just select it.

A material having high adhesion, for example, a Cr film may be formed on the side wall 3 before a material having low adhesion, for example, a Ni film is formed. In this case, two crucibles 7 around which a heater 8 as an evaporation source is wound, one for Cr and one for Ni, are installed in the ultrafine particle generation chamber 5, and after a predetermined amount of Cr ultrafine particles are produced, Ultra fine particles may be produced.

As for the shape of the nozzle 14, any shape such as circular or rectangular may be used as long as a necessary pressure difference can be obtained between the ultrafine particle generating chamber 5 and the film forming chamber 12.
For example, the width 9 which is the same as the shape of the groove 2 as in this embodiment.
The shape may be 0 μm and length 10 mm.

[0026]

As is apparent from the above description, according to the method for forming a drive electrode of an ink jet apparatus of the present invention, conductive ultrafine particles are generated in the ultrafine particle generating chamber in the first step, and In the two steps, the conductive ultrafine particles are formed in the film forming chamber by the differential pressure between the ultrafine particle forming chamber and the film forming chamber, so that the drive electrodes are formed by spraying the side walls.
The ejection speed of the conductive ultrafine particles is high, the drive electrode can be efficiently formed in a short time, and thus the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an ink ejecting apparatus of the invention.

FIG. 2 is an explanatory diagram showing formation of drive electrodes of the ink ejecting apparatus of the invention.

FIG. 3 is a front view showing a nozzle portion of the drive electrode forming apparatus of the present invention.

FIG. 4 is an explanatory diagram showing drive electrode formation of the ink ejecting apparatus of the invention.

FIG. 5 is a cross-sectional view showing a part of an array of a conventional ink ejecting apparatus.

FIG. 6 is an explanatory diagram of an operation of a conventional ink ejecting apparatus.

FIG. 7 is an explanatory diagram showing a method of forming drive electrodes for an ink ejecting apparatus of a conventional example.

[Explanation of symbols]

 1 Piezoelectric Ceramics Plate 2 Groove 3 Sidewall 4 Drive Electrode 5 Ultrafine Particle Generation Chamber 6 Inert Gas 9 Metal Vapor 10 Ultrafine Particle Chamber 12 Film Formation Chamber 21 Polarization Direction 41 Ink Jet Device

Claims (4)

[Claims] 1. A piezoelectric portion, at least a part of which is provided, has a side wall forming an ink chamber, and a drive electrode formed on the piezoelectric portion. The side wall is deformed by applying a voltage to the drive electrode. In the method of forming a drive electrode for an ink ejecting apparatus that ejects ink from an ink chamber by a method, a first step of generating conductive ultrafine particles in an ultrafine particle generation chamber, A method of forming a drive electrode for an ink jet device, comprising: a second step of spraying the side wall to form the drive electrode by a pressure difference between the fine particle generation chamber and the film formation chamber. 2. The conductive ultrafine particles are made of Al, Ni, C.
evaporate metal such as r or conductive material such as NiCr alloy,
2. The method for forming a drive electrode of an ink jet apparatus according to claim 1, wherein the vapor is cooled and agglomerated by colliding with an inert gas such as Ar or He. 3. The method for forming a drive electrode of an ink jet apparatus according to claim 1, wherein the differential pressure between the ultrafine particle generation chamber and the film formation chamber is 3 Kg / cm ² or more. 4. A third step of producing insulating ultrafine particles in the ultrafine particle producing chamber subsequent to the second step, and the insulating ultrafine particles to the drive electrode in the film forming chamber. The method for forming a drive electrode of an ink ejecting apparatus according to claim 1, comprising a fourth step of spraying to form a protective film for the drive electrode.