JP2003118110A - Ink-jet recording head and ink-jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording head and an ink-jet recorder which can hold ink discharge characteristics good and can also uniform the characteristics. SOLUTION: The ink-jet recording head is provided with a channel formation substrate 10 where pressure generation chambers 12 communicating with nozzle openings are formed, and piezoelectric elements 300 set via a diaphragm to one face side of the channel formation substrate 10 for generating a pressure change to the interior of the pressure generation chambers 12. A plurality of connecting parts 100A are set on a common electrode 60 shared by the plurality of piezoelectric elements 300, to which an external wiring line connected to a driving circuit for driving the piezoelectric elements 300 is connected. Moreover, the plurality of these connecting parts 100A are connected by a wiring electrode 65 set on the common electrode 60. A resistance value of the common electrode 60 is substantially decreased accordingly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric element, in which a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets is composed of a vibrating plate, and a piezoelectric element is formed on the surface of the vibrating plate. The present invention relates to an inkjet recording head and an inkjet recording device that eject ink droplets by displacement.

[0002]

2. Description of the Related Art A part of a pressure generating chamber that communicates with a nozzle opening for ejecting ink droplets is composed of a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber to eject it from the nozzle opening. Two types of inkjet recording heads that eject ink droplets have been put into practical use: one that uses a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of a piezoelectric element, and one that uses a flexural vibration mode piezoelectric actuator. ing.

The former allows the volume of the pressure generating chamber to be changed by bringing the end face of the piezoelectric element into contact with the vibrating plate, and a head suitable for high-density printing can be manufactured. There is a problem in that the manufacturing process is complicated because a difficult process of matching the array pitch of the openings and cutting into comb teeth or a work of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required.

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

On the other hand, in order to eliminate the disadvantage of the latter 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 Laid-Open No. 5-286131. It has been proposed that the piezoelectric material layer is cut into a shape corresponding to the pressure generating chamber by a lithographic method and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

According to this, the work of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only the piezoelectric element can be densely formed by a precise and simple method such as a lithography method, but also the piezoelectric element. The advantage is that the thickness can be reduced and high speed driving is possible.

[0007]

However, in the ink jet recording head in which the piezoelectric elements are arranged in high density, when a large number of piezoelectric elements are simultaneously driven to eject a large number of ink droplets, a voltage drop occurs. As a result, the amount of displacement of the piezoelectric element becomes unstable and the ink ejection characteristics deteriorate.

Moreover, the applied voltage is likely to be lower as the piezoelectric element is located farther from the connection portion to which the external wiring is connected. For this reason, there is a problem that even if the piezoelectric elements are arranged side by side in a row, the ink ejection characteristics vary depending on the distance from the connection portion.

The electrode of the piezoelectric element formed of a thin film as described above has a relatively high resistance value due to its thin film thickness.
Such problems are particularly likely to occur.

In view of such circumstances, it is an object of the present invention to provide an ink jet type recording head and an ink jet type recording apparatus which can maintain good ink ejection characteristics and can make them uniform.

[0011]

According to a first aspect of the present invention for solving the above-mentioned problems, there is provided a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and one surface side of the flow path forming substrate. In order to drive the piezoelectric element on the common electrode common to a plurality of piezoelectric elements, in an ink jet recording head including a piezoelectric element that is provided via a vibration plate to generate a pressure change in the pressure generating chamber. An ink jet recording head having a plurality of connecting portions to which external wiring connected to the driving circuit is connected, and the plurality of connecting portions are connected by a wiring electrode provided on the common electrode. It is in.

In the first aspect, since the resistance value of the common electrode is substantially reduced by the wiring electrode, there is no voltage drop even if a large number of piezoelectric elements are driven at the same time.
Ink ejection characteristics are stable.

A second aspect of the present invention is the ink jet recording head according to the first aspect, characterized in that at least the common electrode constituting the piezoelectric element is formed by a thin film and a lithography method. It is in.

In the second aspect, the resistance value of the common electrode is relatively high, but the resistance value of the common electrode is effectively reduced by the wiring electrode.

A third aspect of the present invention is the ink jet recording head according to the first or second aspect, characterized in that the common electrode has a thickness of 0.5 μm or less.

In the third aspect, the resistance value of the common electrode is relatively high, but the resistance value of the common electrode is effectively reduced by the wiring electrode.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the wiring electrode is provided on a peripheral wall on a side opposite to a side where the individual electrode of the piezoelectric element of the pressure generating chamber is drawn out. The inkjet recording head is characterized in that the pressure generating chambers are extended along the juxtaposed direction.

In the fourth aspect, the wiring electrode can be formed relatively easily on the common electrode without increasing the size of the head.

A fifth aspect of the present invention is the ink jet recording head according to the fourth aspect, characterized in that the wiring electrode is provided so as to straddle one longitudinal end of the pressure generating chamber. .

In the fifth aspect, it is possible to prevent the stress caused by driving the piezoelectric element from being concentrated on the longitudinal end portion of the pressure generating chamber.

According to a sixth aspect of the present invention, in the fifth aspect, in the region of the wiring electrode facing the pressure generating chamber, a concave portion is formed on the longitudinal end side of the pressure generating chamber, the wiring electrode being removed. An inkjet recording head characterized by having:

In the sixth aspect, the stress applied to the longitudinal end portion of the pressure generating chamber is effectively dispersed by driving the piezoelectric element.

According to a seventh aspect of the present invention, in the sixth aspect, at least a part of the recess is formed with a width wider than the width of the pressure generating chamber, and the end face of the recess and the pressure generating chamber are formed. The inkjet recording head is characterized in that the angle formed with the end face in the width direction is 90 ° or more.

In the seventh aspect, the stress applied to the longitudinal end portion of the pressure generating chamber is effectively dispersed by driving the piezoelectric element.

An eighth aspect of the present invention is the ink jet recording head according to the sixth or seventh aspect, characterized in that the end surface of the recess is substantially circular.

According to the eighth aspect, the stress applied to the longitudinal end portion of the pressure generating chamber can be more effectively dispersed by driving the piezoelectric element.

A ninth aspect of the present invention is characterized in that, in the eighth aspect, the end surface of the piezoelectric element on the side of the wiring electrode is formed in a substantially circular shape which is concentric with the end surface of the recess. Inkjet type recording head.

In the ninth aspect, the rigidity of the vibrating plate at one longitudinal end of the pressure generating chamber is made uniform.

A tenth aspect of the present invention is the ink jet method according to any one of the first to ninth aspects, characterized in that the wiring electrode is formed of a metal having a smaller specific resistance than the common electrode. It is on the recording head.

In the tenth aspect, the resistance of the common electrode is surely reduced, and the occurrence of voltage drop is more reliably prevented.

An eleventh aspect of the present invention is the ink jet recording head according to any one of the first to tenth aspects, characterized in that the thickness of the wiring electrode is 1 μm or more.

In the eleventh aspect, the resistance of the common electrode is surely reduced, and the occurrence of voltage drop is more reliably prevented.

In a twelfth aspect of the present invention, in any one of the first to eleventh aspects, the pressure generating chamber is formed in a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed and formed. The inkjet recording head is characterized by being formed by a lithography method.

In the twelfth aspect, it is possible to manufacture a large number of ink jet recording heads having high density nozzle openings and relatively easily.

A thirteenth aspect of the present invention is an ink jet recording apparatus including the ink jet recording head according to any one of the first to twelfth aspects.

In the thirteenth aspect, it is possible to realize an ink jet recording apparatus with stable ink ejection characteristics and improved reliability.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view of FIG.

As shown in the figure, the flow path forming substrate 10 is a silicon single crystal substrate having a plane orientation (110) in this embodiment. The flow path forming substrate 10 is usually 150 to 3
A thickness of about 00 μm is used, preferably 18
The thickness is preferably about 0 to 280 μm, more preferably about 220 μm. This is because the array 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 provided with an elastic film 50 having a thickness of 1 to 2 μm and 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 to form a silicon single crystal substrate.
The pressure generating chambers 12 partitioned by the plurality of partition walls 11 are arranged side by side in the width direction, and the pressure generating chambers are communicated with the reservoir portion 31 of the reservoir forming substrate 30 described later through the through holes 51 on the outside in the longitudinal direction. A communication portion 13 that forms a part of the reservoir 110 that serves as a common ink chamber of 12 is formed, and is communicated with one end portion of each pressure generation chamber 12 in the longitudinal direction via an ink supply passage 14.

Here, the anisotropic etching is performed by utilizing the difference in the etching rate of the silicon single crystal substrate. For example, in this embodiment, the silicon single crystal substrate is set to K.
When it is dipped in an alkaline solution such as OH, it is gradually eroded and the first (111) plane perpendicular to the (110) plane and the first (111) plane
Forms an angle of about 70 degrees with the (111) plane of
A second (111) plane that makes an angle of about 35 degrees with the (0) plane appears, and the etching rate of the (111) plane is about 1/180 of the etching rate of the (110) plane. Is done using. By such anisotropic etching, it is possible to perform precision machining based on the depth machining of the parallelogram shape formed by the two first (111) planes and the two diagonal second (111) planes. The pressure generating chambers 12 can be arranged in high density.

In the present 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. The pressure generating chamber 12 is provided in the flow path forming substrate 1
It is formed by etching through almost 0 to reach the elastic film 50. Here, the elastic film 50 is
The amount of the alkaline solution that etches the silicon single crystal substrate is extremely small. Further, each ink supply passage 14 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and keeps the flow resistance of the ink flowing into the pressure generation chamber 12 constant. That is, the ink supply path 14 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). The half etching is performed by adjusting the etching time.

On the opening side of the flow path forming substrate 10,
A nozzle plate 20 having a nozzle opening 21 that communicates with the pressure generating chamber 12 on the side opposite to the ink supply path 14 is fixed via an adhesive or a heat-welding film. The nozzle plate 20 has a thickness of, for example, 0.1 to 1
mm, a coefficient of linear expansion of 300 ° C. or less, for example, 2.5 to
It is made of glass ceramics of 4.5 [× 10 ⁻⁶ / ° C.] or rust-free steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 with one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. Further, the nozzle plate 20 is used as the flow path forming substrate 10.
It may be made of a material having substantially the same thermal expansion coefficient. In this case, since the flow path forming substrate 10 and the nozzle plate 20 have substantially the same deformation due to heat, they can be easily joined using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12 that applies the ink droplet ejection pressure to the ink and the size of the nozzle opening 21 that ejects the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink drops per inch, it is necessary to accurately form the nozzle openings 21 with a diameter of several tens of μm.

On the other hand, a thickness of, for example, about 0.2 μm is formed on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10.
The lower electrode film 60, the piezoelectric layer 70 having a thickness of, for example, about 1 μm, and the upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated in a process described below to form the piezoelectric element 30.
Configures 0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 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 layer 70 are patterned for each pressure generating chamber 12. Further, here, a portion which is composed of one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the lower electrode film 60 is the common electrode of the piezoelectric element 300, and the upper electrode film 80 is the individual electrode of the piezoelectric element 300.
There is no problem in reversing this due to the driving circuit and wiring.
In any case, the piezoelectric active portion is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by the driving of the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

Here, as shown in FIG. 3, the piezoelectric element 30
Each upper electrode film 80, which is an individual electrode of 0, extends from the vicinity of the end opposite to the ink supply path 14 to the vicinity of the end of the flow path forming substrate 10, for example, from gold (Au) or the like. The lead electrode 90 is connected, and the vicinity of the end portion of the lead electrode 90 is a connection portion 100 to which an external wiring (not shown) connected to a drive circuit for driving the piezoelectric element 300 is connected.

The lower electrode film 60, which is the common electrode of the piezoelectric element 300, is continuously extended in the direction in which the pressure generating chambers 12 are arranged in parallel, and is patterned near one end of the piezoelectric element 300. . That is, the lower electrode film 60 is continuously provided in the area other than the area where the lead electrode 90 extends. In addition, the pressure generating chamber 12 of the lower electrode film 60
100 A of connection parts to which external wiring is connected are respectively provided in the vicinity of the end portions in the parallel arrangement direction.

In this embodiment, the wiring electrode 65 made of a conductive material is provided on the lower electrode film 60 via the peripheral wall of the pressure generating chamber 12 opposite to the side from which the lead electrode 90 is drawn out. Of the wiring electrode 65
Both ends of each of them are connection parts 100A. That is, each connection portion 100A of the lower electrode film 60 is connected to the wiring electrode 6
It is electrically connected by 5.

The material of the wiring electrode 65 is not particularly limited, but it is preferable to use a metal having a relatively small specific resistance such as gold (Au), copper (Cu), aluminum (Al), and the like. It is desirable to use a metal whose specific resistance is smaller than that of the lower electrode film 60.

In such a configuration, the resistance value of the lower electrode film 60 can be substantially reduced by the wiring electrode 65, and a voltage drop will not occur even if a large number of piezoelectric elements are driven at the same time. Therefore, it is possible to always eject ink droplets of a predetermined size, and it is possible to always maintain good print quality.

Further, such a wiring electrode 65 is preferably extended so as to straddle the longitudinal end portion of the pressure generating chamber 12, as shown in FIG. Thereby, when the piezoelectric element 300 is driven, it is possible to prevent stress from concentrating in the vicinity of the end portion in the longitudinal direction of the pressure generating chamber 12. Therefore, due to repeated driving of the piezoelectric element 300, cracks or the like do not occur in the diaphragm, and durability and reliability can be improved.

Further, as shown in FIG. 5A, it is preferable that a recess 66 is formed by removing a part of the wiring electrode 65 in the region of the wiring electrode 65 facing the pressure generating chamber 12. Further, it is preferable that the recess 66 is formed such that the width of the end face of the wiring electrode 65 is wider than that of the pressure generating chamber 12, and the angle θ formed between the end face of the recess 66 and the width direction end face of the pressure generating chamber 12. Is preferably 90 ° or more.

The shape of the recess 66 is not particularly limited, but it is preferable that the end surface has a substantially circular shape. In addition, when the end surface of the concave portion 66 has a substantially circular shape, as shown in FIG.
As shown in (b), it is preferable that the end surface 300a of the piezoelectric element 300 on the wiring electrode 65 side has a circular shape that is substantially concentric with the end surface of the recess 66.

By forming the wiring electrode 65 and the piezoelectric element 300 in such a shape, the stress applied to the vicinity of the end of the pressure generating chamber 12 due to the driving of the piezoelectric element 300 is dispersed without being partially concentrated. Therefore, it is possible to more reliably prevent the vibration plate from being broken.

The piezoelectric element 300 of the flow path forming substrate 10
On the side, a reservoir portion 31 that constitutes at least a part of a reservoir 110 that serves as a common ink chamber for each pressure generation chamber 12
The reservoir forming substrate 30 having the is bonded. In the present embodiment, the reservoir portion 31 is formed through the reservoir forming substrate 30 in the thickness direction and across the width of the pressure generating chamber 12, and is a through hole provided through the elastic film 50. A reservoir 110, which is connected to the communication portion 13 of the flow path forming substrate 10 via 51 and serves as a common ink chamber for each pressure generating chamber 12, is configured.

As the reservoir forming substrate 30, it is preferable to use a material having substantially the same coefficient of thermal expansion as that of the passage forming substrate 10, for example, glass or a ceramic material. It was formed using a silicon single crystal substrate of the same material.

In addition, the piezoelectric element 3 of the reservoir forming substrate 30
In a region facing 00, a piezoelectric element holding portion 32 that can seal the space is provided in a state where a space that does not hinder the movement of the piezoelectric element 300 is secured, and the piezoelectric element 300 includes the piezoelectric element holding portion 32. It is sealed inside.

The reservoir forming substrate 30 has a compliance substrate 4 including a sealing film 41 and a fixing plate 42.
0 is joined. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm).
Etc.). The area of the fixing plate 42 facing the reservoir 110 is the opening 4 completely removed in the thickness direction.
Therefore, the one surface of the reservoir 110 is sealed only by the sealing film 41 having flexibility, and is a flexible portion 33 that can be deformed by a change in internal pressure.

The ink jet recording head according to the present embodiment as described above takes in ink from an external ink supply means (not shown), and the nozzle opening 2 from the reservoir 110.
After filling the inside with ink up to 1, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12 via the external wiring in accordance with a recording signal from a drive circuit (not shown). Is applied to the elastic film 50 and the lower electrode film 60.
By flexurally deforming the piezoelectric layer 70, the pressure inside each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

An example of the method of manufacturing the ink jet recording head of this embodiment will be described below with reference to FIGS. 6 and 7. 6 and 7 are sectional views showing a part of the pressure generating chamber 12 in the longitudinal direction.

First, as shown in FIG. 6A, about 110 wafers of a silicon single crystal substrate to be the flow path forming substrate 10 are prepared.
An elastic film 50 made of silicon dioxide is formed by thermal oxidation in a 0 ° C. diffusion furnace.

Next, as shown in FIG. 6B, the lower electrode film 60 is formed on the entire surface of the elastic film 50 by sputtering, and then the lower electrode film 60 is patterned to form an overall pattern. Platinum (Pt) or the like is suitable as a material for the lower electrode film 60. This is because the piezoelectric layer 70 described later, which is formed by the sputtering method or the sol-gel method, needs to be crystallized by baking at a temperature of about 600 to 1000 ° C. in the air atmosphere or the oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain the conductivity under such a high temperature and oxidizing atmosphere, and especially when lead zirconate titanate (PZT) is used as the piezoelectric layer 70. It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and platinum is preferable for these reasons.

Next, as shown in FIG. 6C, the piezoelectric layer 70 is formed. The piezoelectric layer 70 preferably has crystals oriented. For example, in the present embodiment, a so-called sol-gel method is used in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried, gelled, and fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. To form a piezoelectric layer 70 in which crystals are oriented. As a material for the piezoelectric layer 70, a lead zirconate titanate-based material is suitable for use in an inkjet recording head. The method for forming the piezoelectric layer 70 is not particularly limited, and may be formed by, for example, a sputtering method.

Further, after forming a precursor film of lead zirconate titanate by a sol-gel method or a sputtering method,
A method of growing crystals at a low temperature by a high-pressure treatment method in an alkaline aqueous solution may be used.

In any case, in the piezoelectric layer 70 thus formed, the crystals are preferentially oriented unlike the bulk piezoelectric body, and in the present embodiment, the piezoelectric layer 70 has the crystals. It has a columnar shape. Note that the preferential orientation means that the crystal orientation direction is not disordered, and a specific crystal plane is oriented in a substantially constant direction. Further, a thin film having a columnar crystal means a state in which crystals having a substantially columnar body are aggregated in a plane direction with the central axes substantially aligned with the thickness direction to form a thin film. Of course, it may be a thin film formed of preferentially oriented granular crystals. The thickness of the piezoelectric layer manufactured in the thin film process is generally 0.2 to 5 μm.

Next, as shown in FIG. 6D, the upper electrode film 80 is formed. The upper electrode film 80 may be made of a material having high conductivity, and many metals such as aluminum, gold, nickel and platinum, and a conductive oxide can be used. In this embodiment, platinum is deposited by sputtering.

Next, as shown in FIG. 7A, only the piezoelectric layer 70 and the upper electrode film 80 are etched to remove the piezoelectric element 3.
00 patterning is performed.

Next, as shown in FIG. 7B, the lead electrode 90 is formed. For example, in the present embodiment, gold (A
A film to be the lead electrode 90 made of u) or the like is formed over the entire surface of the flow path forming substrate 10, and then this film is patterned for each piezoelectric element 300 to form each lead electrode 90.

Next, as shown in FIG. 7C, the wiring electrode 65 is formed on the lower electrode film 60. That is, the wiring electrode 65 is formed on the entire surface of the flow path forming substrate 10 and then etched to form a predetermined pattern. This wiring electrode 65
Is preferably formed of a metal having a smaller specific resistance than that of the lower electrode film 60 as described above, and examples thereof include gold, copper, and aluminum. In this embodiment, gold is formed by sputtering.

The above is the film forming process. After the film formation is performed in this way, anisotropic etching of the silicon single crystal substrate is performed using the above-described alkaline solution, and
As shown in (d), the pressure generating chamber 12, the communication portion 13, the ink supply passage 14, and the like are formed, and then the lower electrode film 60 and the elastic film 50 are penetrated to form a through hole 51.

In practice, a large number of chips are simultaneously formed on one wafer by the above-described series of film formation and anisotropic etching, and after the process, one chip size as shown in FIG. The flow path forming substrate 10 is divided. Then, the reservoir forming substrate 30 and the compliance substrate 40 are sequentially adhered to and integrated with the divided flow path forming substrate 10 to form an ink jet recording head.

(Other Embodiments) Although one embodiment of the present invention has been described above, the configuration of the present invention is not limited to the above.

For example, in the above-described embodiment, the connecting portion 100A of the lower electrode film 60 which is the common electrode is provided at two places, but the number of connecting portions is not particularly limited, and of course, it may be provided at three or more places. You may

Further, for example, in the above-described embodiment, the vicinity of the end portion of the lead electrode 90 is the connection portion 100 of the upper electrode film 80 which is the individual electrode of the piezoelectric element 300, but the connection of the lower electrode film 60. Similar to the portion 100A, for example, a connection layer made of the same layer as the wiring electrode 65 may be provided in a region of the lead electrode 90 which becomes the connection portion 100.

Further, for example, in the above-described embodiment, the thin film type ink jet recording head manufactured by applying the film formation and the lithographic process is taken as an example. However, the present invention is not limited to this. The present invention can also be applied to a thick film type ink jet recording head formed by a method such as attaching a green sheet.

The ink jet recording head of each of these embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. Figure 8
It is a schematic diagram showing an example of the ink jet type recording device.

As shown in FIG. 8, the recording head units 1A and 1B having the ink jet recording head are detachably provided with the cartridges 2A and 2B constituting the ink supply means.
The carriage 3 on which B is mounted is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B are, for example,
The black ink composition and the color ink composition are respectively discharged.

The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the carriage 3 having the recording head units 1A and 1B mounted thereon follows the carriage shaft 5. Be moved. On the other hand, a platen 8 is provided on the apparatus body 4 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a feed roller (not shown), is conveyed onto the platen 8. It is like this.

[0080]

As described above, according to the present invention, the wiring electrode provided on the common electrode can substantially reduce the resistance value of the common electrode. Therefore, even if a large number of piezoelectric elements are driven at the same time, a voltage drop does not occur, and stable ink ejection characteristics can always be obtained.

[Brief description of drawings]

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

FIG. 2 is a sectional view of the ink jet recording head according to the first embodiment of the invention.

FIG. 3 is a plan view showing a wiring pattern of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a plan view showing a modification of the wiring pattern of the ink jet recording head according to the first embodiment of the invention.

FIG. 5 is a main part plan view showing a modified example of the wiring pattern of the ink jet recording head according to the first embodiment of the invention.

FIG. 6 is a cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

FIG. 7 is a cross-sectional view showing the manufacturing process of the inkjet recording head according to the first embodiment of the invention.

FIG. 8 is a schematic diagram of an inkjet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

10 Flow path forming substrate 12 Pressure generation chamber 20 nozzle plate 21 nozzle opening 30 Reservoir forming substrate 40 compliance board 60 Lower electrode film 65 wiring electrode 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 100,100A connection 110 reservoir 300 Piezoelectric element

Claims (13)

[Claims] 1. A flow passage forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, and a pressure change is generated in the pressure generating chamber provided on one surface side of the flow passage forming substrate via a vibration plate. In an ink jet recording head including a piezoelectric element, a plurality of connecting portions to which an external wiring connected to a drive circuit for driving the piezoelectric element is connected are provided on a common electrode common to the plurality of piezoelectric elements. An ink jet recording head characterized in that the plurality of connecting portions are connected by a wiring electrode provided on the common electrode. 2. The ink jet recording head according to claim 1, wherein at least the common electrode forming the piezoelectric element is formed by a thin film and a lithography method. 3. The ink jet recording head according to claim 1, wherein the common electrode has a film thickness of 0.5 μm or less. 4. The pressure generating chamber according to claim 1, wherein the wiring electrode is provided on a peripheral wall of the pressure generating chamber opposite to a side where the individual electrode of the piezoelectric element is pulled out. An ink jet recording head, which is characterized by being extended along the line. 5. The ink jet recording head according to claim 4, wherein the wiring electrode is provided so as to straddle one longitudinal end of the pressure generating chamber. 6. The inkjet according to claim 5, wherein the wiring electrode has a recess in the region facing the pressure generating chamber, the concave portion having the wiring electrode removed on the longitudinal end side of the pressure generating chamber. Recording head. 7. The method according to claim 6, wherein at least a part of the recess is formed to have a width wider than a width of the pressure generating chamber,
Further, the ink jet recording head is characterized in that an angle formed by an end face of the recess and an end face in the width direction of the pressure generating chamber is 90 ° or more. 8. The ink jet recording head according to claim 6, wherein the end surface of the recess has a substantially circular shape. 9. The ink jet recording head according to claim 8, wherein the end surface of the piezoelectric element on the side of the wiring electrode is formed in a substantially circular shape that is concentric with the end surface of the recess. 10. The ink jet recording head according to claim 1, wherein the wiring electrode is formed of a metal having a specific resistance smaller than that of the common electrode. 11. The ink jet recording head according to claim 1, wherein the wiring electrode has a thickness of 1 μm or more. 12. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed in a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and a lithography method. An ink jet recording head characterized by being present. 13. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.