JP2001322275A - Ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change an ejection quantity of ink without changing a size of an ink jet head by each specification and to improve the stability in the manufacturing, the driving performance and the durability. SOLUTION: A first piezoelectric material substrate 2 and a second piezoelectric material substrate 3 are stacked with a first adhesive layer 4 therebetween and an ink channel 5 is formed by being partitioned by a first partition wall 2a of the first piezoelectric material substrate 2 and a second partition wall 3a of the second piezoelectric material substrate 3. Electrodes 6 are provided to the first partition wall 2a and the second partition wall 3a. The second piezoelectric material substrate 3 and a cover substrate 7 are stacked with a second adhesive layer 8 therebetween, thereby forming the ink jet head 1 wherein a voltage is applied to the electrode 6 to deform the ink channel 5 so that the ink is ejected therefrom. The length of the first partition wall 2a in the stacking direction and the length of the partition wall of the second partition wall 3a in the stack direction are different with each other. The thickness of each of the first adhesive layer 4 and the second adhesive layer 8 is not greater than 10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head for discharging ink by applying a voltage to an electrode to deform an ink channel.

[0002]

2. Description of the Related Art In an ink jet head, a first piezoelectric material substrate and a second piezoelectric material substrate are laminated, and a first partition of the first piezoelectric material substrate and a second piezoelectric material substrate are provided. An ink channel is defined by the second partition wall, electrodes are provided on the first partition wall and the second partition wall, a cover substrate is laminated on the second piezoelectric material substrate, and a voltage is applied to the electrodes to form the ink channel. Is deformed to eject ink.

[0003]

Although such an ink jet head is provided in a printing apparatus or the like, it may be necessary to change the ink discharge amount without changing the size of the ink jet head depending on the specification.

[0004] Further, the ink jet head has a structure in which a first piezoelectric material substrate and a second piezoelectric material substrate are laminated, and further, a cover substrate is laminated on the second piezoelectric material substrate. Therefore, the production stability of the inkjet head may vary depending on the characteristics of the adhesive layer.

In addition, the ink-jet head charges and discharges a capacitor for driving. At this time, most of the energy is generated as Joule heat in a circuit, a part is generated by an electrode of an actuator, and a part is generated by a drive IC. These heats may change the properties of the adhesive layer.

Further, since the ink in the ink channel comes into contact with the adhesive layer, the driving performance of the ink jet head may change or the durability may differ depending on the characteristics of the adhesive layer.

The present invention has been made in view of the above point, and it is possible to change the ink discharge amount without changing the size of the ink jet head depending on the specification.
It is another object of the present invention to provide an ink jet head having improved production stability, drive performance and durability.

[0008]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to the first aspect of the present invention, there is provided a method wherein “a substrate is polarized in a thickness direction of a substrate and a first piezoelectric material substrate and a second piezoelectric material substrate are opposed to each other in the polarization direction. Laminating with an adhesive layer interposed therebetween, an ink channel is partitioned by a first partition of the first piezoelectric material substrate and a second partition of the second piezoelectric material substrate, and the first partition and the An ink jet head for applying a voltage to an electrode provided on a second partition to deform the ink channel to discharge ink, wherein the length of the first partition in the stacking direction and the length of the second partition in the stacking direction are different. An ink jet head characterized in that the length is different from the length. ].

According to the first aspect of the present invention, the length of the first partition for partitioning the ink channel in the stacking direction and the length of the second partition are determined.
By making the length of the partition walls different from the length in the stacking direction,
The ink ejection amount can be freely changed with a simple structure without changing the size of the inkjet head.

According to a second aspect of the present invention, there is provided a method as described below, wherein "the first piezoelectric material substrate and the second piezoelectric material substrate which are polarized in the thickness direction of the substrate and face each other in the polarization direction. The first adhesive layer is interposed and laminated, and an ink channel is defined by a first partition of the first piezoelectric material substrate and a second partition of the second piezoelectric material substrate. An electrode is provided on the partition wall and the second partition wall, a second adhesive layer is interposed between the second piezoelectric material substrate and the cover substrate, and the ink channel is formed by applying a voltage to the electrode. An ink jet head for discharging ink by being deformed, wherein the thickness of the first adhesive layer and the second adhesive layer is 10 μm or less. ].

According to the second aspect of the invention, the thickness of the first adhesive layer and the second adhesive layer is 10 μm or less, and the first adhesive layer and the second adhesive layer are provided on the ink channel side. It can be firmly bonded without protruding.

According to a third aspect of the present invention, there is provided the method as described above, wherein the first adhesive layer and the second adhesive layer have a thermal expansion coefficient of 100 ppm.
3. The inkjet head according to claim 2, wherein the ratio is not more than / deg. ].

According to the third aspect of the present invention, the first adhesive layer and the second adhesive layer have a coefficient of thermal expansion of 100 ppm / d.
EG or less, and heat is generated by driving the ink jet head 1, but the expansion is small due to the influence of the heat, and the driving performance is not impaired.

According to a fourth aspect of the present invention, there is provided the ink jet head according to the second aspect, wherein the first adhesive layer and the second adhesive layer have a hardness of 60 degrees or more. ].

According to the fourth aspect of the present invention, the hardness of the first adhesive layer and the second adhesive layer is 60 degrees or more, and the durability of the ink jet head is improved.

According to a fifth aspect of the present invention, there is provided a method as set forth above, wherein the first adhesive layer and the second adhesive layer have a tensile shear strength of 10N.
The inkjet head according to claim 2, characterized in that at / mm ² or more. ].

According to the fifth aspect of the present invention, the first adhesive layer and the second adhesive layer have a tensile shear strength of 10 N / m.
m ² or more, and the durability of the inkjet head is improved.

According to a sixth aspect of the invention, there is provided an ink jet head according to the second aspect, wherein the first and second adhesive layers have a water absorption of 5% or less. ].

According to the sixth aspect of the present invention, the first and second adhesive layers have a water absorption of 5% or less, and the adhesive strength does not decrease even if they come into contact with ink. The durability is improved.

According to a seventh aspect of the invention, there is provided an ink jet head according to the second aspect, wherein the first and second adhesive layers have an oil absorption of 5% or less. ].

According to the seventh aspect of the present invention, the first and second adhesive layers have an oil absorption of 5% or less, and the adhesive strength does not decrease even if they come into contact with ink. The durability is improved.

According to an eighth aspect of the present invention, there is provided an ink jet head according to the second aspect, wherein the first adhesive layer and the second adhesive layer are two-part epoxy resins. ].

According to the invention described in claim 8, the first adhesive layer and the second adhesive layer are two-part epoxy resins,
It can be firmly bonded in a short time, and productivity and durability are improved.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the ink jet head according to the present invention will be described, but embodiments of the present invention are not limited thereto.

FIG. 1 shows an ink jet head. 2 to 4 show the manufacture of the ink jet head, FIG. 2 shows a lamination of a first piezoelectric material substrate and a second piezoelectric material substrate, and FIG. 3 shows the formation of an ink channel. FIG. 4 is a diagram showing a configuration of an ink jet head in which a cover substrate is laminated.

The ink jet head 1 according to this embodiment
Are a first piezoelectric material substrate 2 and a second piezoelectric material substrate 3
Are laminated with a first adhesive layer 4 interposed therebetween (FIG. 2).
Grooves are formed in the laminated first piezoelectric material substrate 2 and second piezoelectric material substrate 3 at predetermined intervals from the second piezoelectric material substrate 3 side. First partition 2
a and the second partition 3a of the second piezoelectric material substrate 3 define the ink channel 5 (FIG. 3).

Electrodes 6 are provided on the first partition 2a and the second partition 3a by vapor deposition, and are laminated between the second piezoelectric material substrate 3 and the cover substrate 7 with a second adhesive layer 8 interposed therebetween. (FIG. 4). An ink supply port 7 a for supplying ink to the ink channel 5 is formed in the cover substrate 7. A nozzle plate 9 having a nozzle hole 9 a is provided at an end of the first piezoelectric material substrate 2, the second piezoelectric material substrate 3, and the cover substrate 7.

A wiring pattern 20 is provided on the second piezoelectric material substrate 3 so as to be connected to the electrode 6. A wiring 21 is connected to the wiring pattern 20, and a voltage is applied from the wiring 21 to the electrodes 6 provided on the first partition 2 a and the second partition 3 a to deform the ink channel 5 and discharge ink. Has become.

The piezoelectric material of the first piezoelectric material substrate 2 and the second piezoelectric material substrate 3 is not particularly limited as long as it causes a stress change when a voltage is applied, and known materials are used. A substrate made of an organic material may be used, but a substrate made of a piezoelectric nonmetal material is preferable.As the substrate made of this piezoelectric nonmetal material, for example, a ceramic substrate formed through a process such as molding and firing, Alternatively, there is a substrate formed without the need for molding and firing. Examples of the organic material include an organic polymer and a hybrid material of an organic polymer and an inorganic substance.

As a ceramic substrate, PZT (Pb
There are ZrO ₃ -PbTiO ₃ and PZT with a third component added, and Pb (Mg _1/2 Nb _2/3 ) O ₃ and Pb (M
n _1/3 Sb _2/3 ) O ₃ , Pb (Co _1/3 Nb _2/3 ) O _{3 and the} like, and further, BaTiO ₃ , ZnO, LiNbO ₃ , LiT
It can be formed using aO ₃ or the like.

The substrate formed without the need for molding and firing can be formed, for example, by the Solgel method, coating of a laminated substrate, or the like. According to the Solgel method, a sol is converted into a homogeneous solution having a predetermined chemical composition, water,
It is adjusted by adding an acid or an alkali to cause a chemical change such as hydrolysis. Further, by performing a treatment such as evaporation or cooling of the solvent, a sol in which a precursor of fine particles of a desired composition or a non-metallic inorganic fine particle is dispersed is prepared and can be used as a substrate. A compound having a uniform chemical composition can be obtained, including the addition of a small amount of a different element, and a water-soluble metal salt or metal alkoxide such as sodium silicate is generally used as a starting material. A compound represented by the formula M (OR) n, in which the OR group has a strong basic property, is easily hydrolyzed, and changes into a metal oxide or a hydrate thereof through a condensation process like an organic polymer. .

As a method of coating a laminated substrate, there is a method of vapor deposition from a vapor phase. A method of forming a ceramic substrate from a vapor phase includes a vapor deposition method by physical means and a production method by a chemical reaction of the vapor phase or the substrate surface. The physical vapor deposition method (PVD) is further subdivided into a vacuum vapor deposition method, a sputtering method, an ion plating method, and the like, and the chemical method is a gas phase chemical reaction method (CVD) and a plasma CVD method. There are laws. Vacuum evaporation as physical vapor deposition (PVD) is a method in which a target substance is heated and evaporated in a vacuum, and the vapor is deposited on a substrate. Sputtering is a method in which high-energy particles are applied to a target substance (target). This method utilizes the sputtering phenomenon, in which atoms and molecules on the target surface exchange momentum with the colliding particles, and are repelled from the surface. Further, the ion plating method is a method of performing deposition in an ionized gas atmosphere. Further, in the CVD method, a compound containing atoms, molecules or ions constituting the film is made into a gaseous phase, and then guided to a reaction section with an appropriate carrier gas, and the film is reacted or deposited on a heated substrate to form a film. Forming
In the plasma CVD method, a gas phase is generated by plasma energy, and a film is deposited by a gas phase chemical reaction in a relatively low temperature range from 400 ° C. to 500 ° C.

The material of the cover substrate 7 is not particularly limited.
Although a substrate made of an organic material may be used, a substrate made of a non-piezoelectric non-metallic material is preferable. As a substrate made of this non-piezoelectric non-metallic material, alumina, aluminum nitride,
It is preferable to be selected from at least one of zirconia, silicon, silicon nitride, silicon carbide, and quartz.

This non-piezoelectric material substrate includes, for example, a ceramic substrate formed by steps such as molding and firing, and a substrate formed without the need for forming and firing. As a ceramic substrate formed by
For example, Al ₂ O ₃ , SiO ₂ , a mixture thereof, a mixed melt thereof, ZrO ₂ , BeO, AeN, SiC or the like can be used. Examples of the organic material include an organic polymer and a hybrid material of an organic polymer and an organic substance.

As the metal that forms the electrode 6, gold, silver, aluminum, palladium, nickel, tantalum, and titanium can be used.
Aluminum is good and is formed by plating, vapor deposition and sputtering.

In the embodiment of the present invention, as shown in FIG. 4, the length of the first partition wall 2a and the second partition wall 3a in the laminating direction of the ink channel 5 is h, and the lamination of the first partition wall 2a is h. The length of the second partition 3a in the stacking direction is b, the width of the ink channel 5 is Wc, the width of the first partition 2a and the second partition 3a is Ww, Assuming that the thickness of the first adhesive layer 4 is ds and the thickness of the second adhesive layer 8 is dc, Examples 1 and 2 were configured as follows.

Example 1 The length h of the ink channel 5 in the stacking direction was 310 μm, the length a of the first partition 2a in the stacking direction was 150 μm, the length b of the second partition 3a in the stacking direction was 160 μm, and The width Wc of the channel 5 is 80 μm, the width Ww of the first partition 2 a and the second partition 3 a is 60 μm, and the thickness ds of the first adhesive layer 4.
Was set to 3 μm, and the thickness dc of the second adhesive layer 8 was set to 3 μm.

Example 2 The length h of the ink channel 5 in the stacking direction was 360 μm, the length a of the first partition 2a in the stacking direction was 200 μm, and the length b of the second partition 3a in the stacking direction was 160 μm. The width Wc of the ink channel 5, the first partition 2a and the second partition 3a
, The thickness ds of the first adhesive layer 4 and the second adhesive layer 8
Was the same as in Example 1.

As described above, the length a in the stacking direction of the first partition 2a for partitioning the ink channel 5 and the second partition 3a
Is different from the length b in the stacking direction of the ink jet head, it is possible to freely change the ink discharge amount with a simple structure without changing the size of the inkjet head 1.
The length a of the first partition 2a in the stacking direction and the second partition 3a
The length b in the stacking direction is such that when a = b, the electromechanical deformation of the maximum efficiency is not necessarily given, but when a> b, the displacement amount of the first partition 2a that moves hardly increases and the efficiency improves. In addition, when a <b, the amount of displacement of the second partition 3a, which is easy to move, is increased, and the efficiency is improved.

Also, in the embodiment of the present invention, the thickness ds, dc of the first adhesive layer 4 and the second adhesive layer 8 is 10 μm or less, preferably 5 μm or less. Thus, the first adhesive layer 4 and the second adhesive layer 8 can be firmly bonded without protruding.

The inkjet head 1 charges and discharges a capacitor for driving. At this time, most of the energy is converted into Joule heat in a circuit, and part of the energy
A part of the heat is generated by the drive IC (not shown), and the heat may change the characteristics of the adhesive layer. In this embodiment, however, the thermal expansion coefficients of the first adhesive layer 4 and the second adhesive layer 8 are different. Is not more than 100 ppm / deg, preferably 50p / deg.
pm / deg or less, whereby heat is generated by driving the ink-jet head 1. However, the heat is less likely to expand and the driving performance is not impaired.

Further, the first adhesive layer 4 and the second adhesive layer 8
Is not less than 60 degrees, and preferably not less than 80 degrees, so that the first piezoelectric material substrate 2, the second piezoelectric material substrate 3, and the cover substrate 7 are not displaced. Durability is improved.

Further, the first adhesive layer 4 and the second adhesive layer 8
Has a tensile shear strength of 10 N / mm ^TwoOver and preferred
Or 20 N / mm^TwoThis is the first pressure.
Electrically conductive material substrate 2, second piezoelectric material substrate 3, cover substrate
7 is strong and the inkjet head 1 is durable.
The performance is improved.

The first adhesive layer 4 and the second adhesive layer 8
Has a water absorption of 5% or less, and preferably 2% or less, so that even if it touches the ink, it absorbs little water and the durability is improved without lowering the adhesive strength.

The first adhesive layer 4 and the second adhesive layer 8
Has an oil absorption of 5% or less, and preferably 2% or less. Even if the ink comes into contact with the ink, the oil is less absorbed and the durability is improved without lowering the adhesive strength.

Further, the first adhesive layer 4 and the second adhesive layer 8
However, since it is a two-part epoxy resin, it can be firmly adhered in a short time, and productivity and durability are improved.

[0048]

As described above, according to the first aspect of the present invention, the length of the first partition that partitions the ink channel in the stacking direction and the length of the second partition in the stacking direction are set to different lengths. By doing so, it is possible to freely change the ink ejection amount with a simple structure without changing the size of the ink jet head.

According to the second aspect of the present invention, the thickness of the first adhesive layer and the second adhesive layer is 10 μm or less, and the first adhesive layer and the second adhesive layer protrude toward the ink channel side. It can be firmly bonded without any.

According to the third aspect of the present invention, the first adhesive layer and the second adhesive layer have a thermal expansion coefficient of 100 ppm / deg.
In the following, heat is generated by driving the ink-jet head 1, but the heat is less likely to expand due to the influence of the heat, and the driving performance is not impaired.

According to the fourth aspect of the invention, the hardness of the first adhesive layer and the second adhesive layer is 60 degrees or more, and the durability of the ink jet head is improved.

According to the fifth aspect of the present invention, the first adhesive layer and the second adhesive layer have a tensile shear strength of 10 N / mm ^2.
As described above, the durability of the inkjet head is improved.

According to the present invention, the first adhesive layer and the second adhesive layer have a water absorption of 5% or less, so that even if they come into contact with ink, the adhesive strength is not reduced and the durability is low. Is improved.

According to the seventh aspect of the present invention, the first and second adhesive layers have an oil absorption of 5% or less, so that even if they come into contact with ink, the adhesive strength is not reduced and the durability is low. Is improved.

According to the present invention, the first adhesive layer and the second adhesive layer are two-part epoxy resins, can be firmly adhered in a short time, and have high productivity and durability. Is improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an inkjet head.

FIG. 2 is a diagram illustrating lamination of a first piezoelectric material substrate and a second piezoelectric material substrate.

FIG. 3 is a diagram illustrating formation of an ink channel.

FIG. 4 is a diagram illustrating a configuration of an inkjet head in which cover substrates are stacked.

[Explanation of symbols]

 Reference Signs List 1 inkjet head 2 first piezoelectric material substrate 2a first partition 3 second piezoelectric material substrate 3a second partition 4 first adhesive layer 5 ink channel 6 electrode 7 cover substrate 8 second adhesive layer

Claims (8)

[Claims] A first piezoelectric material substrate and a second piezoelectric material substrate which are polarized in a thickness direction of the substrate and are opposed to each other in the polarization direction; An ink channel defined by a first partition of the first piezoelectric material substrate and a second partition of the second piezoelectric material substrate, and electrodes provided on the first and second partitions. An ink jet head that applies a voltage to the ink channel to discharge the ink by deforming the ink channel, wherein the length of the first partition in the stacking direction and the length of the second partition in the stacking direction are set to different lengths. An ink jet head, characterized in that: 2. A first adhesive layer is interposed between a first piezoelectric material substrate and a second piezoelectric material substrate which are polarized in the thickness direction of the substrate and are opposed to each other in the polarization direction. The first partition wall of the first piezoelectric material substrate and the second partition wall.
An ink channel is defined by the second partition of the piezoelectric material substrate, electrodes are provided on the first partition and the second partition, and a second electrode is provided between the second piezoelectric material substrate and the cover substrate. An ink jet head that is stacked with an adhesive layer interposed therebetween, applies a voltage to the electrode, deforms the ink channel, and discharges ink. The thickness of the first adhesive layer and the second adhesive layer is 10μ
m or less. 3. The ink jet head according to claim 2, wherein the first adhesive layer and the second adhesive layer have a coefficient of thermal expansion of 100 ppm / deg or less. 4. The ink jet head according to claim 2, wherein the first and second adhesive layers have a hardness of 60 degrees or more. 5. The ink jet head according to claim 2, wherein the first adhesive layer and the second adhesive layer have a tensile shear strength of 10 N / mm ² or more. 6. The ink jet head according to claim 2, wherein the first adhesive layer and the second adhesive layer have a water absorption of 5% or less. 7. The ink jet head according to claim 2, wherein said first adhesive layer and said second adhesive layer have an oil absorption of 5% or less. 8. An ink jet head according to claim 2, wherein said first adhesive layer and said second adhesive layer are two-part epoxy resins.