JPH1178015A - Ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a contact part against crack, breakage, or the like, due to concentration of stress without sacrifice of displacement efficiency. SOLUTION: The ink jet recording head comprises a plurality of pressure generation chambers 12 communicating with a nozzle opening, and a piezoelectric element 300 including at least a lower electrode 60, a piezoelectric layer 70, and an upper electrode 80 formed in a region corresponding to the pressure generation chamber 12a. Displacement of a piezoelectric actuator is increased by locating the joint of the piezoelectric element 300 and a lead electrode 100 for applying a voltage to the piezoelectric element 300 in a region facing a channel communicating with the pressure generation chamber 12 except the region facing the pressure generation chamber 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element formed in a part of a pressure generating chamber communicating with a nozzle opening for discharging an ink drop via a vibration plate, and the ink drop is discharged by displacement of the piezoelectric element. The present invention relates to an ink jet recording head and an ink jet recording apparatus.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass the nozzle opening. There are two types of ink jet recording heads that eject ink droplets, one using a longitudinal vibration mode piezoelectric actuator in which the piezoelectric element expands and contracts in the axial direction, and the other using a flexural vibration mode piezoelectric actuator in which the piezoelectric element bends. Has been put to practical use.

In the former method, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric element into contact with the diaphragm, so that a head suitable for high-density printing can be manufactured. There is a problem in that a difficult process of cutting into a comb shape in accordance with the arrangement pitch of the openings and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required, and the manufacturing process is complicated.

On the other hand, in the latter, a piezoelectric element can be formed on a diaphragm by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of a pressure generating chamber and firing the green sheet. In addition, there is a problem that a certain area is required due to the use of flexural vibration, and that high-density arrangement is difficult.

On the other hand, in order to solve the latter disadvantage of the recording head, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which the piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by a lithography method, and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

[0006] According to this, the operation of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only can the piezoelectric element be manufactured by a precise and simple method such as lithography, but also the thickness of the piezoelectric element can be reduced. There is an advantage that it can be made thin and can be driven at high speed. In this case, the piezoelectric actuator corresponding to each pressure generating chamber can be driven by providing at least only the upper electrode for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the vibration plate.

In a recording head using such a flexural mode piezoelectric actuator, lead electrodes for supplying a voltage for driving the piezoelectric actuator corresponding to each pressure generating chamber are provided corresponding to each pressure generating chamber. Have been.

[0008]

However, as described above, the connection between the piezoelectric element and the lead electrode (hereinafter referred to as a contact) corresponding to each pressure generating chamber generates a large stress due to the driving of the piezoelectric actuator. There is a problem that it is easy to cause cracks and breakage.

In the contact portion, the displacement due to the application of the voltage is smaller than that of the other portion because the lead electrode is connected. Nevertheless, the compliance is not smaller than that of the other portion. In addition, there is a problem that the ejection speed is reduced and the driving voltage is increased.

These problems are particularly problematic when the piezoelectric material layer is formed by a film forming technique. That is, the piezoelectric material layer formed by the film forming technique is extremely thin, and has lower rigidity than that of a piezoelectric element attached.

In view of such circumstances, the present invention provides an ink jet type recording head and an ink jet type recording apparatus which can prevent cracks, breakage, etc. due to stress concentration at a contact portion and prevent a reduction in displacement efficiency of the contact portion. The task is to provide.

[0012]

According to a first aspect of the present invention, there is provided a fuel cell system comprising: a plurality of pressure generating chambers communicating with a nozzle opening; and at least a lower electrode and a piezoelectric body provided in a region corresponding to the pressure generating chamber. In an ink jet recording head in which a piezoelectric element including a layer and an upper electrode is formed, a connecting portion between a lead electrode for applying a voltage to the piezoelectric element and the piezoelectric element is different from a region other than a region facing the pressure generating chamber. An ink jet recording head is provided in a region facing a flow path communicating with a pressure generating chamber.

In the first aspect, since the connection between the lead electrode and the piezoelectric element is formed in a region other than the region facing the pressure generating chamber, the displacement of the piezoelectric actuator can be increased.

According to a second aspect of the present invention, in the first aspect, a narrow portion having at least one of a width and a depth smaller than the pressure generating chamber is connected to an end of the pressure generating chamber far from the nozzle opening. And a communication portion communicating with the pressure generating chamber through the narrow portion, wherein a connection portion between the piezoelectric element and the lead electrode is provided in a region facing the communication portion. And an ink jet recording head.

In the second aspect, since the connection portion with the lead electrode is formed at a position facing the communication portion that is in communication with the pressure generating chamber via the narrow portion, deformation at the connection portion is prevented. There is almost no breakage of the piezoelectric layer and the like near the connection part, and there is no influence of the displacement reduction by the connection part.

According to a third aspect of the present invention, in the second aspect, the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the upper electrode is provided for each region facing the pressure generating chamber. The pressure generating chamber is formed independently and narrower than the width thereof, and is connected to a portion provided in a region facing the communication portion via a narrow lead portion provided in a portion facing the narrow portion. The ink jet recording head is characterized in that the ink jet recording head is formed.

In the third aspect, even when a voltage is applied through the lead electrode, stress is not concentrated on the piezoelectric layer in the narrow portion and the communicating portion, and the piezoelectric layer and the like are prevented from being broken.
The pressure generating chamber can be effectively displaced.

According to a fourth aspect of the present invention, in the second aspect, the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the upper electrode is provided for each region facing the pressure generating chamber. The pressure generating chamber is formed independently and narrower than the width thereof, and is connected to a portion provided in a region facing the communication portion via a narrow lead portion provided in a portion facing the narrow portion. Wherein the piezoelectric layer is formed in the pressure generating chamber so as to correspond to the upper electrode, and extends with substantially the same width to a region corresponding to the narrow portion and the communication portion. An ink jet recording head is characterized in that:

In the fourth aspect, since the piezoelectric layer is provided up to the position facing the outside of the flow path in the region facing the narrow portion, the boundary portion between the narrow portion and the pressure generating chamber and the communicating portion is particularly provided. Therefore, the displacement of the piezoelectric layer can be further suppressed, and the breakage of the piezoelectric layer can be further prevented.

According to a fifth aspect of the present invention, in the second aspect, the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the piezoelectric layer and the upper electrode are connected to the pressure generating chamber. Each of the opposing regions is independently formed to be narrower than the width of the pressure generating chamber, and is provided in a region opposing the communication portion via a narrow lead portion provided in a portion opposing the narrow portion. An ink jet recording head is formed so as to be continuous with a portion.

In the fifth aspect, the piezoelectric layer is provided so as to face the pressure generating chamber, the narrow portion, and the communication portion. However, even when a voltage is applied through the lead electrode, the piezoelectric layer is formed in the narrow portion and the communication portion. Can hardly be displaced, and can effectively displace the pressure generating chamber.

According to a sixth aspect of the present invention, in any one of the third to fifth aspects, the lead portion which is formed to be narrow, the portion of the region facing the pressure generating chamber, and the communicating portion are opposed to each other. In the ink jet type recording head, a boundary portion with a region to be formed is formed in an R shape.

In the sixth aspect, since the boundary between both ends of the lead portion is formed in an R shape, cracks and the like are further less likely to occur.

According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the communication portion is connected to a common flow path communicating with each of the pressure generating chambers through the narrow portion. An ink jet recording head is characterized in that:

According to the seventh aspect, it is possible to prevent the vibration near the connection portion due to the application of the voltage from the lead electrode, and to further suppress the occurrence of cracks in the piezoelectric element.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the insulator having a window on an upper surface of the upper electrode at least at a portion corresponding to the connection portion with the lead electrode. An ink jet recording head, wherein a layer is formed.

In the eighth aspect, by providing the insulator layer, insulation between the upper electrode and the lower electrode and isolation from the atmosphere can be ensured.

A ninth aspect of the present invention is the ink jet recording head according to the eighth aspect, wherein the insulator layer is formed of an organic material such as silicon oxide, silicon nitride, or polyimide. It is in.

In the ninth aspect, for example, an insulator layer can be easily formed by a film forming step and a lithography step.

According to a tenth aspect of the present invention, in the first to ninth aspects, the piezoelectric element is formed on an elastic film formed on a flow path forming substrate defining the pressure generating chamber. An ink jet recording head is characterized in that:

In the tenth aspect, the elastic film is deformed by the piezoelectric element, and the pressure in the pressure generating chamber changes.

According to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the pressure generation chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation. An ink jet recording head is formed by a lithography method.

In the eleventh aspect, an ink jet recording head having high-density nozzle openings can be manufactured in a large amount and relatively easily.

According to a twelfth aspect of the present invention, there is provided an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to eleventh aspects.

According to the twelfth aspect, it is possible to realize an ink jet recording apparatus in which the driving efficiency of the head is improved and the ink can be discharged satisfactorily.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention.
FIG. 2 is a plan view of FIG. 1 and a diagram showing a cross-sectional structure of one of the pressure generating chambers in a longitudinal direction.

As shown in the figure, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with a 1-2 μm-thick elastic film 50 made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
A nozzle opening 11, a pressure generating chamber 12, a narrow portion 13, and a communication portion 14 are formed.

Here, in the anisotropic etching, when the silicon single crystal substrate is immersed in an alkaline solution such as KOH, the substrate is gradually eroded, and the first (111) plane perpendicular to the (110) plane and the first (111) plane The second (11) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
1) plane appears, and the etching rate of the (111) plane is about 1/18 as compared with the etching rate of the (110) plane.
This is performed using the property of being 0. By such anisotropic etching, two first (111)
Precision machining can be performed based on depth machining of a parallelogram formed by two second (111) surfaces and diagonals, and the pressure generating chambers 12 can be arranged at high density.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. Each narrow portion 13 communicating with the pressure generating chamber 12 on the side opposite to the nozzle opening 11 is a pressure generating chamber 1.
2, and the communication portions 14 communicating with the narrow portions 13 have substantially the same width as the pressure generating chamber 12. The pressure generating chamber 12, the narrow portion 13, and the communication portion 14 pass through the flow path forming substrate 10 substantially, and
And these are formed by etching in the same step. The elastic film 50 is not affected by an alkaline solution for etching the silicon single crystal substrate.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed to be narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11
Is formed by etching (half-etching) the silicon single crystal substrate halfway in the thickness direction. Note that the half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 that applies the ink droplet discharge pressure to the ink, the size of the nozzle opening 11 that discharges the ink droplet, and the size of the narrow portion 13 that controls the flow of ink into and out of the pressure generating chamber 12 are described. The size is optimized according to the amount of the ink droplet to be ejected, the ejection speed, and the ejection frequency. For example, when recording 360 ink droplets per inch, the nozzle opening 11 and the narrow portion 13 need to be formed with a groove width of several tens of μm with high accuracy. In the present embodiment, the depth of the narrow portion 13 is the same as the depth of the pressure generating chamber 12 and the like. However, for example, the depth may be reduced by half etching similarly to the nozzle opening 11.

The communication section 14 is a relay chamber for connecting a common ink chamber 31 described later and the pressure generating chamber 12 through the narrow section 13, and an ink supply section for the sealing plate 20 described later. The communication ports 21 correspond to each other, and the ink is supplied from the common ink chamber 31 through the ink supply communication ports 21 and distributed to the pressure generating chambers 12. In the present embodiment, the communication section 14 is provided for each of the pressure generation chambers 12, but may be a common flow path that communicates with all the pressure generation chambers 12 via the narrow section 13. In this case, Alternatively, the communicating portion may function as a common ink chamber described later.

The sealing plate 20 is connected to the ink supply communication port 2 described above.
1 is perforated, the thickness is, for example, 0.1 to 1 mm, the linear expansion coefficient is 300 ° C. or less, for example, 2.5 to 4.5 [×
10 ⁻⁶ / ° C.]. In addition, as shown in FIGS. 3A and 3B, the ink supply communication port 21 has one slit hole 21 traversing each communication port 14.
A or a plurality of slit holes 21B. The sealing plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. In addition, the sealing plate 20
The other surface forms one wall surface of the common ink chamber 31.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness according to the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and one surface thereof constitutes one wall of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10, for example, a thickness of about 0.5 μm
A lower electrode film 60, a piezoelectric film 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are formed by lamination in a process to be described later.
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also, here
The combination of the piezoelectric element 300 and the vibration plate whose displacement is generated by driving the piezoelectric element 300 is referred to as a piezoelectric actuator. In the example described above, the elastic film 50 and the lower electrode film 6
Although 0 functions as a diaphragm, the lower electrode film may also serve as an elastic film.

Here, a process for forming the piezoelectric film 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIGS.

As shown in FIG. 4A, first, a silicon single crystal substrate wafer serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, a lower electrode film 60 is formed by sputtering. Pt or the like is preferable as the material of the lower electrode film 60. This is because a piezoelectric film 70 described later, which is formed by a sputtering method or a sol-gel method,
After film formation, 600 to 10 in an air atmosphere or an oxygen atmosphere
This is because it is necessary to perform crystallization by firing at a temperature of about 00 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere. In particular, when PZT is used for the piezoelectric film 70, the conductivity of the material by diffusion of PbO is increased. It is desirable that there is little change in sex, and Pt is preferred for these reasons.

Next, as shown in FIG. 4C, a piezoelectric film 70 is formed. The piezoelectric film 70 can be formed by a sputtering method, but in the present embodiment, a so-called sol in which a metal organic substance is dissolved and dispersed in a solvent is applied, dried, gelled, and further baked at a high temperature. A so-called sol-gel method for obtaining a piezoelectric film 70 made of a metal oxide is used. As a material for the piezoelectric film 70, a lead zirconate titanate (PZT) -based material is suitable when used in an ink jet recording head.

Next, as shown in FIG. 4D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and many metals such as Al, Au, Ni, and Pt, and a conductive oxide can be used. In the present embodiment, P
t is formed by sputtering.

Next, as shown in FIG. 4E, a piezoelectric element is provided for each of the pressure generating chambers 12.
The upper electrode film 80 and the piezoelectric film 70 are patterned. FIG. 4E shows a case where the piezoelectric film 70 is patterned with the same pattern as the upper electrode film 80. However, as described above, the piezoelectric film 70 does not necessarily need to be patterned. This is because, when a voltage is applied using the pattern of the upper electrode film 80 as an individual electrode, an electric field is applied only between each upper electrode film 80 and the lower electrode film 60 which is a common electrode. This has no effect. However, in this case, it is necessary to apply a large voltage to obtain the same excluded volume. Therefore, it is preferable to pattern the piezoelectric film 70 as well. Thereafter, the lower electrode film 60 is patterned to remove unnecessary portions.

Next, as shown in FIG. 5A, an insulator layer 90 is formed so as to cover the periphery of the upper electrode film 80 and the side surfaces of the piezoelectric film 70. Suitable materials for the insulator layer 90 are as described above, but in the present embodiment, a negative photosensitive polyimide is used.

Next, as shown in FIG. 5B, a window 90a is formed in a portion facing each communication portion 14 by patterning the insulator layer 90. The window 90a is for connecting a lead electrode 100 described later and the upper electrode film 80.

Next, for example, a lead electrode 100 is formed by depositing a conductor such as Cr-Au on the entire surface and then patterning it.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 5C, the silicon single crystal substrate is anisotropically etched with the above-described alkali solution to form the pressure generating chamber 12 and the like. In addition,
The series of film formation and anisotropic etching described above
A large number of chips are simultaneously formed on one wafer, and after completion of the process, the wafer is divided into flow path forming substrates 10 having one chip size as shown in FIG. Further, the divided flow path forming substrate 10 is sequentially adhered and integrated with the sealing plate 20, the common ink chamber forming substrate 30, and the ink chamber side plate 40 to form an ink jet recording head.

The ink-jet head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown), fills the interior from the common ink chamber 31 to the nozzle opening 11 with ink, and then fills the interior with ink (not shown). According to a recording signal from an external drive circuit, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 via the lead electrode 100, and the elastic film 50, the lower electrode film 60, and the left electric film 70 are connected. The pressure generating chamber 1 is deformed by bending.
The pressure in 2 increases, and ink droplets are ejected from nozzle opening 11.

Here, the lead electrode 1 in this embodiment is
FIG. 6 shows a positional relationship between the pressure generating chamber 12 and a contact portion, which is a connecting portion between the second electrode 00 and the upper electrode film 80.

As shown in FIG. 6, in this embodiment, the piezoelectric film 70 and the upper electrode film 80 are patterned so as to substantially correspond to the shapes of the pressure generating chamber 12, the narrow portion 13, and the communication portion 14. Each of the piezoelectric elements 300 includes a driving section 320 located on the pressure generating chamber 12, a lead section 321 located on the narrow section 13, and a contact forming section 322 located on the communication section 14. 322
A window 90a of the insulator layer 90 is formed thereon, and the window 90a
The inside is connected to the lead electrode 100. That is, the contact forming portion 322 that forms the connection portion with the lead electrode 100 is formed at a position facing the communication portion 14 that does not face the pressure generating chamber 12.

Accordingly, a connection portion with the lead electrode 100 is not formed at a position facing the pressure generating chamber 12, but is formed in a region facing the flow path communicating with the pressure generating chamber 12. In addition, the displacement of the drive unit 320 corresponding to the pressure generating chamber 12 increases, the volume excluded in the pressure generating chamber 12 increases, and there is no fear of cracking, breakage, or the like due to driving.

Further, since the contact formation portion 322 having the connection portion with the lead electrode 100 is formed at a position facing the communication portion 14 having a relatively small area, the contact formation portion 322 itself is hardly displaced. There is no danger of cracking or breakage of the contact forming portion 322.

Further, by providing the contact forming portion 322 at a position facing the communication portion 14, the compliance is almost eliminated, and the pressure by the piezoelectric element 300 can be effectively used for ink ejection.

However, stress tends to concentrate particularly on the boundary between the both ends of the lead portion 321 and the drive portion 320 and the contact formation portion 322. 7 to 9 may be adopted.

That is, as shown in FIG.
0 is patterned so as to substantially correspond to the shape of the pressure generating chamber 12, the narrow portion 13 and the communication portion 14 as described above. Alternatively, patterning may be performed to have the same width as the portion facing the communication portion 14. This way,
Since the piezoelectric film 70 covers the outside of the ink flow path at the narrow portion 13, the pressure generating chamber 12 and the communication portion 14
Cracks at the boundary with the portion facing the surface are less likely to occur.

As shown in FIG. 8, an outer edge portion 3 which is a boundary portion between the lead portion 321 of the piezoelectric film 70 and the upper electrode film 80 and the drive portion 320 and the contact formation portion 322 is formed.
23 may have an R shape. This makes it more difficult for cracks to occur at the boundary.

Further, the communication portions 14 separately formed corresponding to the respective pressure generating chambers 12 in the above-described embodiment may be a common communication portion 14A as shown in FIG. In this case, since the restraining force of the contact formation portion 322 is reduced, vibration can be further suppressed, and cracks and the like at the boundary with the lead portion 321 are further less likely to occur.

It goes without saying that the configurations shown in FIGS. 7 to 9 may be appropriately combined and used.

(Other Embodiments) One embodiment of the present invention has been described above, but the basic configuration of the ink jet recording head is not limited to the above.

For example, in addition to the sealing plate 20, the common ink chamber forming plate 30 may be made of glass ceramic, and the thin wall 41 may be made of glass ceramic as a separate member. Changes are free.

In the above-described embodiment, the nozzle opening 11 is formed on the end surface of the flow path forming substrate 10, but a nozzle opening protruding in a direction perpendicular to the surface may be formed.

FIG. 10 is an exploded perspective view of the embodiment configured as described above, and FIG. 11 is a cross-sectional view of the flow path. In this embodiment, the nozzle opening 11 is formed in the nozzle substrate 120 opposite to the piezoelectric element, and the nozzle communication port 22 that connects the nozzle opening 11 and the pressure generating chamber 12 is formed with the sealing plate 20 and the common ink chamber. It is arranged so as to penetrate the forming plate 30, the thin plate 41A, and the ink chamber side plate 40A.

In the present embodiment, the thin plate 41
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40A. Is omitted.

Here, also in this embodiment, the window 90a of the insulator layer 90 is formed at a position facing the communication portion 14, and a connection portion with the lead electrode 100 is formed through the window 90a. . Therefore, since a connection portion with the lead electrode 100 is not formed in a region facing the pressure generating chamber 12, the same effect as in the above-described embodiment can be obtained.

In each of the embodiments described above, a thin-film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example. However, the present invention is not limited to this. Various types of ink-jet type, such as one that forms a pressure generating chamber by laminating substrates, one that forms a piezoelectric film by pasting a green sheet or screen printing, or one that forms a piezoelectric film by crystal growth The present invention can be applied to a recording head.

Further, the example in which the insulator layer is provided between the piezoelectric element and the lead electrode has been described. However, the present invention is not limited to this. For example, the insulator layer is not provided and each upper electrode is anisotropically conductive. The film may be thermally welded, and the anisotropic conductive film may be connected to a lead electrode, or may be connected using various bonding techniques such as wire bonding.

As described above, according to the present invention, in any case, the connecting portion between the piezoelectric element and the lead electrode is provided outside the region facing the pressure generating chamber and in the region facing the flow path communicating with the pressure generating chamber. Thereby, the effects of the present invention can be achieved,
The present invention can be applied to ink jet recording heads having various structures, as long as the purpose is not contradicted.

The ink jet recording head of each of the embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge and the like, and is mounted on an ink jet recording apparatus. FIG.
FIG. 1 is a schematic view showing an example of the ink jet recording apparatus.

As shown in FIG. 12, recording head units 1A and 1B having an ink jet recording head are
Cartridges 2A and 2B constituting ink supply means are provided detachably, and a carriage 3 on which the recording head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. I have. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, the apparatus main body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is wound around the platen 8. It is designed to be transported.

[0083]

As described above, in the present invention,
By providing a connection between the lead electrode for applying a voltage to the piezoelectric element and the piezoelectric element in a region other than the region facing the pressure generating chamber, the displacement amount of the piezoelectric actuator can be increased. As a result, the excluded volume in the pressure generating chamber is increased, and since there is no connecting portion in the region facing the pressure generating chamber, there is an effect that there is no risk of cracking, breakage, and the like due to driving.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the inkjet recording head of FIG. 1;

FIG. 3 is a view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a diagram showing a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a thin film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a plan view showing a main part of the first embodiment of the present invention.

FIG. 7 is a main part plan view showing a modification of the first embodiment of the present invention.

FIG. 8 is a main part plan view showing a modification of the first embodiment of the present invention.

FIG. 9 is a main part plan view showing a modification of the first embodiment of the present invention.

FIG. 10 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 11 is a cross-sectional view showing an ink jet recording head according to another embodiment of the present invention.

FIG. 12 is a perspective view schematically showing an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flow path forming substrate 11 Nozzle opening 12 Pressure generating chamber 13 Narrow part 14 Communication part 50 Elastic film 60 Lower electrode film 70 Piezoelectric film 80 Upper electrode film 90 Insulator layer 90a Contact hole 100 Lead electrode 300 Piezoelectric element

Claims (12)

[Claims] A plurality of pressure generating chambers communicating with a nozzle opening, and at least a lower electrode in a region corresponding to the pressure generating chambers;
In an ink jet recording head in which a piezoelectric element including a piezoelectric layer and an upper electrode is formed, a connection between a lead electrode for applying a voltage to the piezoelectric element and the piezoelectric element is other than a region facing the pressure generating chamber. An ink jet recording head is provided in a region facing a flow path communicating with the pressure generating chamber. 2. The pressure generating chamber according to claim 1, wherein the pressure generating chamber communicates with an end of the pressure generating chamber far from the nozzle opening, and at least one of a width and a depth is smaller than the pressure generating chamber, and via the narrow part. An ink jet recording head, comprising: a communication portion that communicates with the pressure generating chamber; and a connection portion between the piezoelectric element and the lead electrode is provided in a region facing the communication portion. 3. The pressure generating chamber according to claim 2, wherein the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the upper electrode is narrower than the width of the pressure generating chamber for each region facing the pressure generating chamber. It is formed independently and is formed so as to be continuous with a portion provided in a region opposed to the communication portion via a narrow lead portion provided in a portion opposed to the narrow portion. Inkjet recording head. 4. The pressure generating chamber according to claim 2, wherein the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the upper electrode is narrower than the width of the pressure generating chamber for each region facing the pressure generating chamber. The piezoelectric element is formed independently and connected to a portion provided in a region opposed to the communication portion via a narrow lead portion provided in a portion opposed to the narrow portion. A body layer is formed corresponding to the upper electrode in a region opposed to the pressure generating chamber, and extends with substantially the same width to a region corresponding to the narrow portion and the communication portion. Ink jet recording head. 5. The pressure generating device according to claim 2, wherein the width of the narrow portion is formed narrower than that of the pressure generating chamber, and the piezoelectric layer and the upper electrode generate the pressure in each region facing the pressure generating chamber. It is formed so as to be independently smaller than the width of the chamber, and is formed so as to be continuous with a portion provided in a region facing the communication portion via a narrow lead portion provided in a portion facing the narrow portion. An ink jet recording head characterized in that: 6. A boundary portion between the lead portion formed narrow and a portion of a region facing the pressure generating chamber and a portion of a region facing the communication portion according to any one of claims 3 to 5. Is formed in an R shape. 7. The ink-jet type according to claim 2, wherein the communication portion comprises a common flow passage communicating with each of the pressure generating chambers via the narrow portion. Recording head. 8. The semiconductor device according to claim 1, wherein an insulating layer having a window is formed on an upper surface of the upper electrode at least in a portion corresponding to the connection portion with the lead electrode. Characteristic inkjet recording head. 9. The ink jet recording head according to claim 8, wherein said insulator layer is formed of an organic material such as silicon oxide, silicon nitride, or polyimide. 10. The piezoelectric device according to claim 1, wherein the piezoelectric element is formed on an elastic film formed on a flow path forming substrate that defines the pressure generating chamber. Ink jet recording head. 11. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and lithography. An ink jet recording head, comprising: 12. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.