JP4284913B2 - Ink jet head, manufacturing method thereof, and ink jet recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inkjet head, a manufacturing method thereof, and an inkjet recording apparatus.
[0002]
[Prior art]
An ink jet head of an ink jet recording apparatus includes a pressure chamber part having a pressure chamber for storing ink liquid, and a ferroelectric element that is an actuator unit for ejecting ink droplets from the pressure chamber. The ferroelectric element includes a ferroelectric film, and an individual electrode and a common electrode that apply a voltage to the ferroelectric film to contract and expand, and the pressure effect of the ferroelectric film is caused by the piezoelectric effect of the ferroelectric film. The ink droplets are ejected from the nozzle holes by changing the volume.
[0003]
In order to stabilize the ejection characteristics of ink droplets ejected from a large number of nozzle holes, it is necessary to suppress variations in the displacement characteristics and resonance characteristics of the ferroelectric elements.
[0004]
Japanese Unexamined Patent Publication No. 2000-301715 discloses a technique for preventing a bonding material from adhering to a displacement portion of a diaphragm in an ink jet in which a head main body portion and an actuator portion are bonded. The structure is such that an intermediate layer provided with a window portion that exposes the displacement portion of the vibration plate to the pressure chamber is formed on the surface of the vibration plate on the head main body side, and the partition wall between the intermediate layer and the main body portion is an electrodeposition layer. The intermediate layer is made of copper, and its thickness is set to 5 μm so that the protruding portion of the bonding material does not adhere to the displacement portion of the diaphragm.
[0005]
[Problems to be solved by the invention]
However, according to the above-described technique, since it is necessary to newly provide an intermediate layer, the number of man-hours at the time of manufacturing increases, leading to a decrease in productivity and an increase in manufacturing cost.
[0006]
Further, when the diaphragm and the partition wall of the pressure chamber are directly joined without providing such an intermediate layer, the applied bonding material is less than the adhesive surface of the partition wall constituting the pressure chamber, and the end surface thereof. May not be bonded or may be bonded to the end face. As a result, the displacement characteristics and the resonance characteristics vary, the ink ejection efficiency deteriorates, and a highly reliable ink jet head cannot be obtained.
[0007]
SUMMARY An advantage of some aspects of the invention is that it provides a technique related to an ink jet head having excellent ink ejection efficiency.
[0008]
[Means for Solving the Problems]
To solve this problem, the ink-jet head of the present invention, a plurality of partition walls forming the pressure chamber, a diaphragm fixed on the partition wall by means of a bonding material so as to cover the pressure chambers, the vibration a ferroelectric film formed on the plate, strong is formed on the dielectric film, and an individual electrode for displacing the ferroelectric film in the direction of changing the volume of the pressure chamber, Young the bonding material The rate is set to 1.0 × E + 8 to 1.0 × E + 10 N / m ² , and the bonding material is configured to protrude inside the formation range of the ferroelectric film along the plane of the diaphragm in the pressure chamber. It is a thing.
[0009]
As a result, it is possible to obtain an ink jet head excellent in ink ejection efficiency by uniformizing the displacement characteristics and resonance characteristics between a plurality of ferroelectric elements.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention includes a plurality of partition walls forming the pressure chamber, a diaphragm fixed on the partition wall by means of a bonding material so as to cover the pressure chambers, on the vibrating plate a ferroelectric film formed on the intensity is formed on the dielectric film, and an individual electrode for displacing the ferroelectric film in the direction of changing the volume of the pressure chamber, the Young's modulus of the bonding material 1 0.0 × E + 8 to 1.0 × E + 10 N / m ² and an ink jet head configured so that the bonding material protrudes inside the formation range of the ferroelectric film along the plane of the diaphragm in the pressure chamber. Thus, the displacement characteristics and resonance characteristics between the plurality of ferroelectric elements are made uniform, and an ink jet head having excellent ink ejection efficiency can be obtained.
[0011]
The invention according to claim 2 of the present invention is the ink jet head according to claim 1, wherein the protruding width of the bonding material in the direction along the plane of the diaphragm is 5 μm or more, and a plurality of ferroelectric materials It has an effect that the displacement characteristic and the resonance characteristic between the elements are made uniform and an ink jet head having excellent ink ejection efficiency can be obtained.
[0013]
Invention of Claim 3 of this invention is an ink jet head whose joining material is an acrylic resin or an epoxy resin in the invention as described in any one of Claims 1-2 , and uses these resin materials. As a result, the variation in the amount of displacement of the diaphragm can be made relatively small, so that the displacement characteristics and resonance characteristics between the plurality of ferroelectric elements are made uniform, and an ink jet head having excellent ink ejection efficiency can be obtained. Has the effect of becoming possible.
[0014]
The invention according to claim 4 of the present invention is the ink jet head according to any one of claims 1 to 3 , wherein the diaphragm also serves as an electrode , and a plurality of ferroelectric elements are arranged between each other. The displacement characteristics and resonance characteristics of the ink jet are made uniform, and it is possible to obtain an ink jet head having excellent ink ejection efficiency.
[0015]
The invention according to claim 5 of the present invention is an ink jet recording apparatus including the ink jet head according to any one of claims 1 to 4 , and can perform high quality printing by stable ink ejection. It has the effect of becoming possible.
[0018]
According to a sixth aspect of the present invention, a diaphragm is bonded to a plurality of partition walls forming a pressure chamber via a bonding material so as to cover the pressure chamber, and the partition wall and the diaphragm are mutually attached. A method of manufacturing an ink-jet head by applying a pressing force in a pressure-contacting direction so that the bonding material protrudes inside the formation range of the ferroelectric film along the plane of the diaphragm in the pressure chamber , When the bonding material is applied to the partition wall or the diaphragm at a position corresponding to the partition wall , the bonding material is raised at the end of the application region corresponding to each pressure chamber in a state of being raised from the region other than the end. This is a method of manufacturing an ink-jet head that coats and can reliably protrude the bonding material and bond / fix the head, so that the displacement characteristics and resonance characteristics between multiple ferroelectric elements are made uniform. Ink with excellent ink ejection efficiency It has the effect that it is possible to obtain the jet head.
[0019]
Hereinafter, embodiments of the present invention will be described with reference to FIGS. In these drawings, the same members are denoted by the same reference numerals, and redundant description is omitted.
[0020]
FIG. 1 is a perspective view showing an overall schematic configuration of an inkjet recording apparatus using a ferroelectric element according to an embodiment of the present invention, and FIG. 2 shows an overall configuration of an inkjet head in the inkjet recording apparatus of FIG. 3 is a perspective view showing the main part of FIG. 2, FIG. 4 is a cross-sectional view showing the ink jet head of FIG. 2, and FIG. 5 is a diagram showing the relationship between the protruding width of the bonding material and the displacement amount of the ferroelectric element. FIG. 6 shows the resonance characteristics when the Young's modulus of the bonding material is 1.0 × E + 7 N / m ² and the protruding width in the direction along the plane of the diaphragm / common electrode is +10 μm, and the Young's modulus of the bonding material. Is a graph showing resonance characteristics when the protrusion width in the direction along the plane of the diaphragm / common electrode is +10 μm with 1.0 × E + 8 N / m ² , FIG. 7 is an inkjet according to one embodiment of the present invention Continuous head manufacturing method FIG. 8 is a cross-sectional view showing the shape of the bonding material applied in the manufacturing process of the inkjet head according to the embodiment of the present invention, and FIG. 9 shows an example of the dimensions of the raised portion of the bonding material in FIG. FIG. 10 is an explanatory view, and FIG. 10 is a cross-sectional view showing the application shape of the bonding material in the manufacturing process of the ink jet head according to the embodiment of the present invention.
[0021]
An ink jet recording apparatus 40 shown in FIG. 1 includes an ink jet head 41 of the present invention that performs recording using the piezoelectric effect of a ferroelectric element, and ink droplets ejected from the ink jet head 41 are recorded on a recording medium 42 such as paper. Is recorded on the recording medium 42. The inkjet head 41 is mounted on a carriage 44 provided on a carriage shaft 43 arranged in the main scanning direction X, and reciprocates in the main scanning direction X as the carriage 44 reciprocates along the carriage shaft 43. Move. Further, the ink jet recording apparatus 40 includes a plurality of rollers (moving means) 45 for moving the recording medium 42 in the sub scanning direction Y substantially perpendicular to the width direction of the ink jet head 41 (that is, the main scanning direction X). .
[0022]
FIG. 2 shows the overall configuration of the inkjet head 41 according to the embodiment of the present invention, and FIG. 3 shows the configuration of the main part thereof. 2 and 3, A is a pressure chamber component, and the pressure chamber opening 1 is formed. B is an actuator portion arranged to cover the upper end opening surface of the pressure chamber opening 1, and C is an ink liquid flow path component arranged to cover the lower end opening surface of the pressure chamber opening 1. The pressure chamber opening 1 of the pressure chamber part A is partitioned by an actuator part B and an ink liquid flow path part C positioned above and below to become a pressure chamber 2. In the actuator part B, an individual electrode (second electrode) 3 located above the pressure chamber 2 is arranged. These pressure chambers 2 and individual electrodes 3 are arranged in a staggered manner as can be seen from FIG. The ink liquid flow path component C includes a common liquid chamber 5 shared between the pressure chambers 2 arranged in the ink liquid supply direction, a supply port 6 that communicates the common liquid chamber 5 with the pressure chamber 2, An ink flow path 7 through which the ink liquid flows is formed. D is a nozzle plate, in which a nozzle hole 8 communicating with the ink flow path 7 is formed. In FIG. 2, E is an IC chip, which supplies a voltage to a large number of individual electrodes 3 via bonding wires BW.
[0023]
Next, the structure of the actuator part B is demonstrated based on FIG.
[0024]
In FIG. 4, the pressure chamber part A having the pressure chambers 2 arranged in the orthogonal direction is drawn for reference.
[0025]
The actuator section includes a plurality of partition walls 2a forming the pressure chamber 2, a diaphragm / common electrode (vibration plate or first electrode) 11 fixed on the partition wall 2a so as to cover the pressure chamber 2, vibrations A ferroelectric film 10 formed on the plate / common electrode 11 and an individual electrode (second electrode) 3 formed on the ferroelectric film 10 are provided. The individual electrode 3 and the diaphragm / common electrode 11 displace the ferroelectric film 10 in cooperation with each other in the direction in which the volume of the pressure chamber 2 is changed.
[0026]
The diaphragm / common electrode 11 is fixed to the partition wall 2a via a bonding material 14 made of, for example, an acrylic resin or an epoxy resin. The bonding material 14 protrudes into the pressure chamber 2 as shown in the figure. The protruding width of the bonding material 14 is 5 μm or more in the direction along the plane of the diaphragm / common electrode 11. The Young's modulus is 1.0 × E + 8 to 1.0 × E + 10 N / m ² .
[0027]
Here, the relationship between the protrusion width of the bonding material 14 and the amount of displacement of the ferroelectric element is shown in FIG.
[0028]
As shown in FIG. 5, it can be seen that the amount of displacement is stable when a bonding material having a small Young's modulus is used and the protrusion width is 5 μm or more. Then, the greater the Young's modulus of the bonding material, the greater the variation in displacement, or the displacement variation increases when the protrusion width is 5 μm or less, particularly when the protrusion width is − (minus). Therefore, from FIG. 5, when the protruding width of the bonding material 14 in the direction along the plane of the diaphragm / common electrode 11 is 5 μm or more and the Young's modulus of the bonding material 14 is 1.0 × E + 10 N / m ² or less. It can be seen that the displacement of the ferroelectric element is stable.
[0029]
FIG. 6 shows resonance characteristics (FIG. 6A) when the Young's modulus of the bonding material is 1.0 × E + 7 N / m ² and the protrusion width in the direction along the plane of the diaphragm / common electrode is +10 μm. FIG. 6B shows resonance characteristics when the Young's modulus of the bonding material is 1.0 × E + 8 N / m ² and the protrusion width in the direction along the plane of the diaphragm / common electrode is +10 μm.
[0030]
In the case shown in FIG. 6A, that is, when the Young's modulus of the bonding material is small, the resonance varies, and in the case shown in FIG. 6B, that is, when the Young's modulus of the bonding material is large, the resonance does not vary. . Therefore, it can be seen that the Young's modulus of the bonding material is desirably 1.0 × E + 8 N / m ² or more from the viewpoint of resonance characteristics.
[0031]
5 and 6 described above, in the present embodiment, as described above, the protruding width of the bonding material 14 is 5 μm or more in the direction along the plane of the diaphragm / common electrode 11, and the Young's modulus is 1.0 × E + 8 to 1.0 × E + 10 N / m ² .
[0032]
In the present embodiment, the first electrode and the diaphragm are integrated (the diaphragm also serves as the first electrode), but both may be formed separately. In that case, a diaphragm is fixed on the partition wall 2a, and the 1st electrode should just be formed on it.
[0033]
In the present embodiment, the individual electrode 3 is made of, for example, Pt (platinum), the ferroelectric film 10 is made of, for example, lead zirconate titanate (PZT), and the diaphragm / common electrode 11 is made of, for example, Cu (copper). Has been. The individual electrode 3 is formed to a thickness of 0.2 μm, for example, the ferroelectric film 10 is formed to a thickness of 3 μm, and the diaphragm / common electrode 11 is formed to a thickness of 5.5 μm, for example.
[0034]
In addition, the individual electrodes 3, the ferroelectric film 10, the diaphragm / common electrode 11 and the like can be formed by various known film forming methods, for example, a thick film method such as screen printing, a coating method such as dipping, a sputtering method, A CVD method, a vacuum deposition method, a sol-gel method, a thin film forming method such as plating, and the like can be appropriately employed, but are not limited thereto.
[0035]
In addition, between the films of the diaphragm / common electrode 11, the ferroelectric film 10, and the individual electrode 3 shown in the present embodiment, for the purpose of improving the bonding of each film, for example, other than these A layer may be interposed.
[0036]
Here, a manufacturing method of the ink jet head having the above-described configuration will be described with reference to FIG.
[0037]
7, first, for example, the individual electrode 3 is formed by epitaxial growth on the MgO substrate 15 (FIG. 7A), and the ferroelectric film 10 having a perovskite structure is formed on the individual electrode 3 (FIG. 7 ( b)), the diaphragm / common electrode 11 is formed on the ferroelectric film 10 (FIG. 7C). Note that when the diaphragm is provided separately from the first electrode, a diaphragm is further formed over the first electrode.
[0038]
Thereafter, the diaphragm / common electrode 11 is fixed to the partition wall 2a so that the bonding material 14 protrudes (FIG. 7D), and the MgO substrate 15 is removed by wet etching using, for example, phosphoric acid (FIG. 7D e)). Finally, when the individual electrode 3 and the ferroelectric film 10 are patterned into a predetermined shape (FIG. 7F), the ink jet head shown in FIG. 4 is obtained.
[0039]
Here, as shown in FIG. 8, if the bonding material 14 is applied to the partition wall 2a by the electrodeposition technique so that the application end portion thereof is raised (FIG. 8A), it is also used as a diaphragm. When the electrode 11 and the partition wall 2a are joined, the protruding portion of the joining material 14 protrudes into the pressure chamber (FIG. 8B), so that the joining material 14 can be easily formed. Note that the bonding material 14 has, for example, an application voltage of 8.5 V, a voltage application time of 60 SEC, and a conforming time of 20 SEC, as shown in FIG. The raised width can be about 30 μm. However, it is also possible to apply the bonding material 14 with the raised application end portion to the diaphragm / common electrode 11 side.
[0040]
Then, if the bonding material 14 is applied so that the application end portion is raised (FIG. 8A) (FIG. 8A), as shown in FIG. 10, the partition wall 2a and the diaphragm / common electrode 11 are formed. And a pressure in the direction in which they are pressed against each other, for example, about 7 kg / cm ^{2 is} applied to cause the bonding material 14 to protrude into the pressure chamber 2, and the viscosity of the bonding material 14 decreases while the pressing force is applied, and this bonding material. The 1st heat processing which heats for about 60 minutes-120 minutes at the temperature (for example, 80 degreeC) in which hardening of 14 does not generate | occur | produce are performed. After the first heat treatment, cooling is performed at room temperature for 30 minutes, for example. After cooling, a second heat treatment is performed by heating for about 120 minutes at a temperature (for example, 180 ° C.) at which the bonding material is cured with the pressing force removed, thereby forming an ink jet head. The temperature rise time in the second heat treatment is, for example, 240 minutes, and the temperature drop time is, for example, 60 minutes.
[0041]
Note that after the first heat treatment, the second heat treatment may be performed without cooling.
[0042]
As described above, according to the present embodiment, the bonding material is protruded into the pressure chambers in at least the in-plane direction of the vibration plate in all the pressure chambers that eject ink, so that the plurality of ferroelectric elements can be connected to each other. Since the displacement characteristics and the resonance characteristics are made uniform, it is possible to obtain an ink jet head having excellent ink ejection efficiency.
[0043]
According to the ink jet recording apparatus provided with such an ink jet head, it is possible to perform high quality printing by stable ink ejection.
[0044]
【The invention's effect】
As described above, according to the present invention, by allowing the bonding material to protrude into the pressure chamber, the displacement characteristics and resonance characteristics between the plurality of ferroelectric elements are made uniform, so that the ink ejection efficiency is excellent. An effective effect that an ink jet head can be obtained is obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall schematic configuration of an ink jet recording apparatus using a ferroelectric element according to an embodiment of the present invention. FIG. 2 is an overall configuration of an ink jet head in the ink jet recording apparatus of FIG. FIG. 3 is a perspective view showing the main part of FIG. 2. FIG. 4 is a sectional view showing the ink jet head of FIG. 2. FIG. 5 is a relationship between the protruding width of the bonding material and the displacement amount of the ferroelectric element. FIG. 6 is a graph showing resonance characteristics when the Young's modulus of the bonding material is 1.0 × E + 7 N / m ² and the protrusion width in the direction along the plane of the diaphragm / common electrode is +10 μm, and the Young of the bonding material FIG. 7 is a graph showing resonance characteristics when the ratio is 1.0 × E + 8 N / m ² and the protrusion width in the direction along the plane of the diaphragm / common electrode is +10 μm. Inkjet head manufacturing method FIG. 8 is a cross-sectional view showing a coating shape of the bonding material in the manufacturing process of the ink jet head according to the embodiment of the present invention. FIG. 9 is an example of a dimension of a protruding portion of the bonding material in FIG. FIG. 10 is a cross-sectional view showing a bonding material application shape in the manufacturing process of the inkjet head according to an embodiment of the present invention.
2 Pressure chamber 2a Partition wall 3 Individual electrode (second electrode)
10 Ferroelectric film 11 Diaphragm / common electrode (diaphragm, first electrode)
14 Bonding material 41 Inkjet head 40 Inkjet recording apparatus

Claims (6)

A plurality of partition walls forming a pressure chamber;
A diaphragm fixed on the partition wall through a bonding material so as to cover the pressure chamber;
A ferroelectric film formed on the diaphragm ;
An individual electrode formed on the ferroelectric film and displacing the ferroelectric film in a direction to change the volume of the pressure chamber ;
The Young's modulus of the bonding material is 1.0 × E + 8 to 1.0 × E + 10 N / m ² ,
An inkjet head characterized in that, in the pressure chamber, the bonding material protrudes along the plane of the diaphragm to the inside of the formation range of the ferroelectric film . The inkjet head according to claim 1, wherein a protruding width of the bonding material in a direction along a plane of the diaphragm is 5 µm or more. The inkjet head according to claim 1 , wherein the bonding material is an acrylic resin or an epoxy resin. The inkjet head according to claim 1 , wherein the diaphragm also serves as an electrode . An ink jet recording apparatus comprising the ink jet head according to claim 1 . Adhering the diaphragm to the plurality of partition walls forming the pressure chamber via a bonding material so as to cover the pressure chamber,
A pressing force is applied in a direction in which the partition wall and the diaphragm are pressed against each other , and the bonding material is formed in the pressure chamber along the plane of the diaphragm in a range in which the ferroelectric film is formed. An inkjet head manufacturing method that protrudes to the inside ,
When the bonding material is applied to the partition wall or the diaphragm at a position corresponding to the partition wall ,
A method for manufacturing an ink jet head , comprising: applying the bonding material to an end portion of an application region corresponding to each pressure chamber in a state of being raised from a region other than the end portion .

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