JP2002210965A - Nozzle plate, ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle plate which can be bonded well to a channel forming substrate, and an ink jet recording head and an ink jet recorder in which pressure generating chambers can be arranged at a high density while preventing crosstalk. SOLUTION: The nozzle plate 20 is bonded, through adhesive, to a silicon single crystal substrate 10 having a plurality of nozzle openings 21 for ejecting liquid drops and in which channels communicating with the nozzle openings 21 are formed. The nozzle plate 20 is bonded well to the channel forming substrate 10 by providing a plurality of recesses 23 in a region serving as a plane being bonded to the channel forming substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate, and a piezoelectric element is provided through the vibrating plate to displace the piezoelectric element. The present invention relates to a nozzle plate, an ink jet recording head, and an ink jet recording apparatus used for an ink jet recording head or the like for ejecting ink droplets according to the present invention.

[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 through the nozzle opening. Two types of ink jet recording heads that eject ink droplets have been commercialized, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and the other using a flexural vibration mode piezoelectric actuator. ing.

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 by a film forming technique over the entire surface of the diaphragm 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]

However, in such an ink jet recording head, since the pressure generating chambers are formed to penetrate the flow path forming substrate, when the arrangement density of the pressure generating chambers is increased, the pressure generating chambers will not generate pressure. There is a problem that the thickness of the partition wall that partitions the chamber becomes thin, and crosstalk occurs between adjacent pressure generating chambers.

In such an ink jet recording head, a nozzle plate having a plurality of nozzle openings for discharging ink droplets is used, and a flow path is formed so that the nozzle openings communicate with the pressure generating chamber. The substrate and the nozzle plate are joined by an adhesive or the like. For this reason,
If the pressure generating chambers are arranged at a high density, the bonding area between the nozzle plate and the flow path forming substrate is reduced, and there is a possibility that the adhesive may excessively flow into the pressure generating chamber.

The present invention has been made in view of the above circumstances, and has been developed in view of the above circumstances.
It is another object of the present invention to provide an ink jet recording head and an ink jet recording apparatus in which pressure generating chambers can be arranged at high density and crosstalk can be prevented.

[0009]

According to a first aspect of the present invention, there is provided a liquid crystal display comprising a single crystal silicon substrate, a plurality of nozzle openings for discharging droplets, and a flow passage communicating with the nozzle openings. In a nozzle plate bonded to a flow path forming substrate on which a passage is formed via an adhesive, a plurality of concave portions are provided in a region serving as an adhesive surface with the flow path forming substrate. Nozzle plate.

In the first aspect, when the nozzle plate and the flow path forming substrate are bonded to each other, useless adhesive flows into the concave portion, so that flow into the flow path is prevented.

According to a second aspect of the present invention, there is provided the nozzle plate according to the first aspect, wherein the concave portion is provided in a region facing a peripheral edge of the flow path.

According to the second aspect, it is possible to more reliably prevent the adhesive from flowing into the flow path.

According to a third aspect of the present invention, in the first or second aspect, a part in the thickness direction is provided in a region corresponding to the nozzle opening on a surface opposite to a bonding surface with the flow path forming substrate. A nozzle plate having a crater portion or a slit portion removed.

In the third aspect, the ink droplet is ejected from the nozzle opening through the crater or the slit,
The periphery of the nozzle opening is protected.

A fourth aspect of the present invention is the nozzle plate according to the third aspect, wherein the concave portion and the crater portion or the slit portion are formed in the same step.

In the fourth aspect, the manufacturing process is simplified, and the concave portion can be formed relatively easily.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the main surface of the single crystal silicon substrate is (1).
00) Orientation, wherein the recess is formed by anisotropic etching.

In the fifth aspect, the depth of the concave portion can be easily controlled, and the concave portion can be formed easily and with high precision.

According to a sixth aspect of the present invention, there is provided a nozzle plate having a nozzle opening, a flow path forming substrate defining a pressure generation chamber communicating with the nozzle opening, and a pressure of the flow path forming substrate. In an ink jet recording head including a lower electrode provided in a region corresponding to a generation chamber via a vibration plate, a piezoelectric element including a piezoelectric layer and an upper electrode, the nozzle plate and the flow path forming substrate are bonded to each other. The ink jet recording head is characterized in that the nozzle plate has a plurality of recesses in a region corresponding to the adhesive on a bonding surface with the flow path forming substrate.

In the sixth aspect, when the nozzle plate and the flow path forming substrate are bonded to each other, useless adhesive flows into the concave portion, so that flow into the pressure generating chamber is prevented, and characteristic deterioration due to bonding is prevented. it can.

According to a seventh aspect of the present invention, in the sixth aspect, the concave portion is provided in a region of the nozzle plate facing a periphery of the pressure generating chamber. It is in.

According to the seventh aspect, it is possible to more reliably prevent the adhesive from flowing into the pressure generating chamber.

An eighth aspect of the present invention is the ink jet recording head according to the sixth or seventh aspect, wherein the nozzle plate is made of a silicon single crystal substrate.

According to the eighth aspect, the nozzle opening and the concave portion can be formed easily and with high precision.

According to a ninth aspect of the present invention, in the eighth aspect, the main surface of the silicon single crystal substrate has a (100) orientation, and the concave portion is formed by anisotropic etching. Ink-jet recording head.

According to the ninth aspect, the depth of the concave portion can be easily controlled, and the concave portion can be formed easily and with high precision.

According to a tenth aspect of the present invention, in any one of the sixth to ninth aspects, the nozzle plate is provided in an area corresponding to the nozzle opening on a surface opposite to a bonding surface with the flow path forming substrate. And a crater portion or a slit portion which is partially removed in the thickness direction.

In the tenth aspect, the ink droplet is discharged from the nozzle opening through the crater or the slit to protect the peripheral edge of the nozzle opening.

According to an eleventh aspect of the present invention, in the tenth aspect, the concave portion of the nozzle plate and the crater portion or the slit portion are formed in the same step. In the head.

In the eleventh aspect, the manufacturing process is simplified, and the concave portion can be formed relatively easily.

A twelfth aspect of the present invention is the ink jet recording head according to any one of the sixth to eleventh aspects, wherein the piezoelectric layer has crystals preferentially oriented.

In the twelfth aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystals are preferentially oriented.

A thirteenth aspect of the present invention is the ink jet recording head according to the twelfth aspect, wherein the piezoelectric layer has a columnar crystal.

In the thirteenth aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystal has a columnar shape.

According to a fourteenth aspect of the present invention, in any one of the sixth to thirteenth aspects, the piezoelectric layer has a thickness of 0.5 to 0.5.
An ink jet recording head having a thickness of 3 μm.

In the fourteenth aspect, since the thickness of the piezoelectric layer is relatively small, high-density patterning is possible.

According to a fifteenth aspect of the present invention, in any one of the sixth to fourteenth aspects, the arrangement density of the pressure generating chambers is 20.
The ink jet recording head is characterized by having a resolution of 0 dpi or more.

In the fifteenth aspect, since the pressure generating chambers are arranged at high density, high-speed and high-quality printing can be realized.

According to a sixteenth aspect of the present invention, in any one of the sixth to fifteenth aspects, the flow path forming substrate has a thickness of 10
An ink jet recording head having a thickness of 0 μm or less.

In the sixteenth aspect, even if the pressure generating chambers are arranged at high density, the rigidity of the partition between the pressure generating chambers is maintained, and crosstalk is prevented.

According to a seventeenth aspect of the present invention, in any one of the sixth to sixteenth aspects, the flow path forming substrate is polished after forming the pressure generating chamber to have a predetermined thickness. The feature is the ink jet recording head.

In the seventeenth aspect, since the passage-forming substrate is polished after the formation of the pressure generating chamber, the handling of the passage-forming substrate is easy, and the thickness of the passage-forming substrate can be easily reduced.

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

In the eighteenth aspect, the pressure generating chamber can be formed relatively easily with high precision and high density.

According to a nineteenth aspect of the present invention, there is provided an ink jet recording apparatus including the ink jet recording head according to any one of the sixth to eighteenth aspects.

According to the nineteenth aspect, an ink jet recording apparatus capable of high-speed and high-quality printing can be realized.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail 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 plan view and a sectional view of FIG.

As shown in the figure, the flow path forming substrate 10 is formed of a silicon single crystal substrate having a plane orientation (110) in this embodiment. One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with an elastic film 50 having a thickness of 1 to 2 μm and made of silicon dioxide formed in advance by thermal oxidation.

In the flow path forming substrate 10, pressure generating chambers 12 divided by a plurality of partition walls 11 are anisotropically etched on a silicon single crystal substrate, and are arranged in parallel in the width direction. The array density of the pressure generating chambers 12 is preferably 200 or more per inch, that is, 200 dpi or more. For example, in this embodiment, 360
dpi. On the outside in the longitudinal direction, there is formed a communication part 13 which forms a part of a reservoir 100 which communicates with a reservoir part of a reservoir forming substrate which will be described later and serves as a common ink chamber of each pressure generation chamber 12. Each of the generating chambers 12 communicates with one longitudinal end of the generating chamber 12 via an ink supply path 14.

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 A second (1) which forms an angle of about 70 degrees with the (111) plane and forms an angle of about 35 degrees with the (110) plane.
11) plane, and the etching rate of the (111) plane is about 1/1 compared to the etching rate of the (110) plane.
This is performed using the property of being 80.
By such anisotropic etching, two first (11
Precision processing can be performed based on depth processing of a parallelogram formed by the 1) plane and two oblique second (111) planes, and the pressure generating chambers 12 can be arranged at high density. it can.

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. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. Here, the elastic film 50 is
The amount attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small. Each of the ink supply passages 14 communicating with one end of each of the pressure generating chambers 12 is formed shallower than the pressure generating chambers 12 and maintains a constant flow resistance of the ink flowing into the pressure generating chambers 12. That is, the ink supply path 14 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. Note that the half etching is performed by adjusting the etching time.

The thickness of the flow path forming substrate 10 may be selected in accordance with the arrangement density of the pressure generating chambers 12. For example, if the arrangement density is about 180 dpi, the flow path formation substrate 10 may be formed. The thickness of the substrate 10 may be about 220 μm.
In the case of arranging at a relatively high density of 0 dpi or more, it is preferable that the thickness of the flow path forming substrate 10 be relatively thin, 100 μm or less. This is because the arrangement density can be increased while maintaining the rigidity of the partition 11 between the adjacent pressure generating chambers 12.

On the other side of the flow path forming substrate 10,
A nozzle plate 20 provided with a nozzle opening 21 communicating with the pressure supply chamber 12 on the side opposite to the ink supply path 14 is joined by an adhesive. The nozzle plate 20 of the present invention is made of a silicon single crystal substrate having a plane orientation (100), and the nozzle openings 21 are formed by dry-etching this silicon single crystal substrate. In addition,
In the present embodiment, the nozzle opening 21 includes a nozzle portion 21a from which ink droplets are ejected, and a nozzle communication portion 21b formed with a larger diameter than the nozzle portion 21a and communicating the nozzle portion 21a and the pressure generating chamber 12. .

Here, the nozzle portion 2 of the nozzle opening 21
The size of 1a and the size of the pressure generating chamber 12 are optimized according to the amount of ink droplets to be ejected, the ejection speed, the ejection frequency, and the like. For example, when recording 360 ink droplets per inch, the nozzle portion 21a needs to be formed with a diameter of several tens μm with high accuracy.

Further, FIG.
As shown in (a), a crater portion 22 having a part removed in a thickness direction is provided in a region corresponding to a row of nozzle openings 21 on a surface opposite to a bonding surface with the flow path forming substrate 10. The peripheral portion of the nozzle opening 21 is protected by the crater portion 22. In the present embodiment, the crater portions 22 are provided continuously corresponding to the plurality of nozzle openings 21, and the nozzle portions 21 a of the respective nozzle openings 21 are opened in the crater portion 22.

In this embodiment, the nozzle plate 2
Although the crater portion 22 is formed by removing a part of the region corresponding to the row of the nozzle openings 21 in the thickness direction at 0,
Without being limited to this, for example, as shown in FIG.
A slit 24 may be provided in which a part of the nozzle plate 20 in the thickness direction is continuously removed up to the end.

In this embodiment, the crater portion 22 is provided continuously in a region corresponding to the row of the nozzle openings 21. Of course, as shown in FIG. It may be provided individually for each.

Further, the nozzle plate 20 of the present embodiment
A plurality of recesses 23 are provided along the periphery of each pressure generating chamber 12 in a portion that is bonded to the flow path forming substrate 10, for example, in a region corresponding to the periphery of the pressure generating chamber 12. By providing such a concave portion 23, as described later in detail,
When the nozzle plate 20 and the flow path forming substrate 10 are bonded to each other with an adhesive, useless adhesive flows into the concave portion 23, thereby preventing the adhesive from excessively flowing into the pressure generating chamber 12. Can be.

Further, since the nozzle plate 20 is formed of the same material as that of the flow path forming substrate 10, the nozzle plate 20 may not be warped in a heating step at the time of bonding to the flow path forming substrate 10 or a heating step of a subsequent step at the time of mounting. No reaction occurs, and no cracks occur in the flow path forming substrate 10 or the nozzle plate 20. In addition, since the nozzle plate 20 is made of a silicon single crystal substrate, the positioning between the concave portion 23 and the pressure generating chamber 12 can be easily and accurately performed by infrared reflection from the nozzle plate 20 side.

The method of forming such a nozzle plate 20 is not particularly limited, but can be formed, for example, by the following steps.

First, as shown in FIG. 4A, one side of a silicon single crystal substrate 200 serving as a nozzle plate is
For example, a mask 210 having an opening 210a of a predetermined shape is provided in a region to be the nozzle opening 21 made of silicon oxide, and dry etching is performed through the mask 210 to form an etching hole 21c. Next, FIG.
As shown in (b), after the mask 210 is half-etched, the silicon single crystal substrate 200 is further dry-etched to form the nozzle openings 21 including the nozzle portions 21a and the nozzle communication portions 21b. In the present embodiment, each of the nozzle portion 21a and the nozzle communication portion 21b is formed by dry etching. However, the present invention is not limited to this, and the nozzle communication portion 21b may be formed by wet etching.

Next, as shown in FIG. 4C, a mask 211 having an opening 211a in a region where the crater portion 22 is formed is provided on the other surface of the silicon single crystal substrate 200, and the silicon single crystal substrate 200 is formed. On one side of
A mask 212 having an opening 212a is provided in a region where the recess 23 is formed. Next, as shown in FIG. 4D, the silicon single crystal substrate 200 is
Is anisotropically etched (half-etched) to form a crater portion 22 having a predetermined depth. Thereby, the crater portion 22 and the nozzle portion 21a of the nozzle opening 21 are formed.
Communicates with At the same time, the silicon single crystal substrate 200 is anisotropically etched through the mask 212 to form the concave portions 23 together with the crater portions 22.

Here, in this embodiment, the nozzle plate 20 is made of a silicon single crystal substrate having a plane orientation (100), and the opening area of each recess 23 is relatively small. Therefore, when the silicon single crystal substrate 200 is anisotropically etched, the (111) plane of the silicon single crystal substrate is exposed and the etching is automatically stopped.
3 can be easily and accurately formed. Note that the depth of the crater portion 22 may be adjusted according to the etching time.

The crater portion 22 and the recess 2
3 can be formed in the same step by simultaneously anisotropically etching the silicon single crystal substrate 200 from both sides. Therefore, the concave portion 23 can be formed relatively easily without increasing the number of manufacturing steps.

In this embodiment, the nozzle plate 2
Although the crater portion 22 communicating with the nozzle portion 21a of the nozzle opening 21 is provided at 0, the crater portion 22 may not be provided. In this case, when the concave portion 23 is formed by etching one surface of the silicon single crystal substrate 200 serving as a nozzle plate, the entire surface of the other surface is simultaneously etched to open the nozzle portion 21a.

On the other hand, the lower electrode film 60 having a thickness of, for example, about 0.2 μm and the piezoelectric film having a thickness of, for example, about 0.5 to 3 μm are formed on the elastic film 50 provided on the flow path forming substrate 10. Body layer 7
0 and an upper electrode film 80 having a thickness of, for example, about 0.1 μm,
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. In general, 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 of the pressure generating chambers 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric layer 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 diaphragm whose displacement is generated by driving the piezoelectric element 300 is referred to as a piezoelectric actuator.

Here, the method of manufacturing such an ink jet recording head is not particularly limited, but one example thereof will be described below with reference to FIGS. 4 and 5 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction.

First, as shown in FIG. 5 (a), a silicon single crystal
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide. It is preferable that the silicon single crystal substrate wafer be as thin as possible.
Since an extremely thin one is difficult to handle, in this embodiment, a thickness of about 200 to 220 μm is used.

Next, as shown in FIG. 5B, after the lower electrode film 60 is formed on the entire surface of the elastic film 50 by sputtering, the lower electrode film 60 is patterned to form an entire pattern. Preferable material for the lower electrode film 60 is platinum (Pt) or the like. This is because it is necessary to crystallize a piezoelectric layer 70 described later formed by a sputtering method or a sol-gel method by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric layer 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and for these reasons, platinum is preferred.

Next, as shown in FIG. 5C, a piezoelectric layer 70 is formed. In the piezoelectric layer 70, it is preferable that crystals are oriented. For example, in the present embodiment, a so-called sol-gel method in which a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst is applied and dried to form a gel, and then 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 when used in an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited, and may be, for example, a sputtering method.

Further, after forming a precursor film of lead zirconate titanate by a sol-gel method, a sputtering method or the like,
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, unlike the bulk piezoelectric, the piezoelectric layer 70 formed as described above has crystals preferentially oriented, and in the present embodiment, the piezoelectric layer 70 has It is formed in a column shape. Note that the preferential orientation refers to a state in which a crystal orientation direction is not disordered and a specific crystal plane is oriented in a substantially constant direction. In addition, a crystal having a columnar thin film refers to a state in which substantially columnar crystals are gathered in a plane direction with their central axes substantially aligned in 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. 5D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In the present embodiment, platinum is formed by sputtering.

Next, as shown in FIG. 6A, only the piezoelectric layer 70 and the upper electrode
00 patterning is performed.

Next, as shown in FIG. 6B, a lead electrode 90 is formed. Specifically, for example, a lead electrode 90 made of, for example, gold (Au) is formed over the entire surface of the flow path forming substrate 10 and is patterned for each piezoelectric element 300.

The above is the film forming process. After forming the film in this manner, anisotropic etching of the silicon single crystal substrate was performed using the above-described alkali solution, and FIG.
As shown in (c), the pressure generating chamber 12, the communication section 13, the ink supply path 14, and the like are formed.

Thereafter, as shown in FIG. 6D, the surface of the flow path forming substrate 10 on the side opposite to the piezoelectric element 300 is polished so that the flow path forming substrate 10 has a predetermined thickness. Then, the thickness was set to about 70 to 80 μm.

After the flow path forming substrate 10 has a predetermined thickness in this way, the nozzle plate 20 having the nozzle openings 21 formed thereon is joined to the flow path forming substrate 10 with an adhesive. At this time, in the present embodiment, since the plurality of recesses 23 are formed in the bonding portion of the nozzle plate 20 with the flow path forming substrate 10, as shown in FIG.
Flows into the concave portion 23, and the adhesive 25
2 does not flow excessively. Thereby, the flow path forming substrate 10 and the nozzle plate 20 can be satisfactorily joined, and the characteristic deterioration due to adhesion can be prevented. On the other hand, when the concave portion 23 is not provided in the nozzle plate 20, the adhesive 25 flows into the pressure generating chamber 12 excessively as shown in FIG. In particular, when the vibration is severe, the adhesive may flow into the diaphragm, and the characteristics may be deteriorated.

As described above, in this embodiment, the flow path forming substrate 10 is polished and thinned, and then the nozzle plate 20 having the concave portion 23 is bonded. Can be satisfactorily bonded, and the thickness of the flow path forming substrate 10 can be relatively easily reduced. As a result, it is possible to prevent the characteristic deterioration due to the adhesion and to improve the rigidity of the partition wall 11, so that the crosstalk can be prevented even if the pressure generating chambers 12 are arranged at a relatively high density. Therefore, it is possible to realize an ink jet recording head that realizes high-speed and high-quality printing.

The concave portion 23 may be formed at any position as long as it is an adhesive portion of the nozzle plate 20 to the flow path forming substrate 10, but as in the present embodiment, the pressure generating chamber 12 Is preferably formed along the periphery of (FIG. 1)
reference). As a result, the flow of the adhesive into the pressure generating chamber 12 can be effectively suppressed.

The piezoelectric element 300, the pressure generating chamber 12, and the like described above form a large number of chips on a single wafer simultaneously by a series of film formation and anisotropic etching. The flow path is divided for each flow path forming substrate 10 of one chip size as shown. Then, a reservoir forming substrate 30 and a compliance substrate 40, which will be described later, are sequentially bonded and integrated with the divided flow path forming substrate 10 to form an ink jet recording head.

That is, as shown in FIGS. 1 and 2, a reservoir section 31 constituting at least a part of the reservoir 100 is provided on the piezoelectric element 300 side of the flow path forming substrate 10 in which the pressure generating chambers 12 and the like are formed. The reservoir forming substrate 30 is joined. In the present embodiment, the reservoir portion 31 is formed so as to penetrate the reservoir forming substrate 30 in the thickness direction and to extend in the width direction of the pressure generating chamber 12. Then, the reservoir portion 31 is formed through the elastic film 50 and the lower electrode film 60 through a through hole 51 provided through the flow path forming substrate 10.
The reservoir 100 is configured to communicate with the communication portion 13 of the pressure generating chamber 12 and serve as a common ink chamber for each pressure generating chamber 12.

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 flow path forming substrate 10, such as glass or ceramic material. It was formed using a silicon single crystal substrate of the same material. As a result, as in the case of the nozzle plate 20 described above, even when bonding is performed at a high temperature using a thermosetting adhesive, both can be reliably bonded. Therefore, the manufacturing process can be simplified.

Further, the reservoir forming substrate 30 includes:
The compliance substrate 40 including the sealing film 41 and the fixing plate 42 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 31. Has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SU) having a thickness of 30 μm.
S) etc.). The reservoir 10 of the fixing plate 42
Since the region opposing to 0 is an opening 43 completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with the sealing film 41 having flexibility, and the internal pressure changes. Thus, the flexible portion 32 is deformable.

Further, an ink introduction port 35 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 substantially outside the central portion in the longitudinal direction of the reservoir 100. Further, the reservoir forming substrate 30 is provided with an ink introduction path 36 that communicates the ink introduction port 35 with the side wall of the reservoir 100.

On the other hand, the piezoelectric element 3 of the reservoir forming substrate 30
A piezoelectric element holding portion 33 that seals the space is provided in a region opposed to 00 while securing a space that does not hinder the movement of the piezoelectric element 300. At least the piezoelectric active portion 320 of the piezoelectric element 300 is sealed in the piezoelectric element holding portion 33 to prevent the piezoelectric element 300 from being destroyed due to an external environment such as moisture in the atmosphere.

The ink jet recording head thus constructed takes in ink from an ink inlet 35 connected to an external ink supply means (not shown), and fills the inside from the reservoir 100 to the nozzle opening 21 with ink. By applying a voltage between the upper electrode film 80 and the lower electrode film 60 in accordance with a recording signal from an external drive circuit (not shown), the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are flexibly deformed. Then, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle opening 21.

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

For example, in the above-described embodiment, a thin-film type ink jet recording head manufactured by applying a film forming and lithography process has been described 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 sticking.

In the above-described embodiment, an ink jet recording head having a flexural displacement type piezoelectric element has been described. For example, a vertical material having a structure in which a piezoelectric material and an electrode forming material are alternately sandwiched and laminated. The present invention can be applied to an ink jet recording head having a vibration mode piezoelectric element.

Further, the present invention is not limited to the above-described piezoelectric vibration type ink jet recording head, but may be applied to various types of ink jet recording heads such as a bubble jet (registered trademark) type ink jet recording head. Needless to say.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the gist of the present invention is not contradicted.

Further, the application of the nozzle plate of the present invention described in the above embodiment is not limited to the ink jet recording head, but can be applied to other liquid ejecting apparatuses which discharge droplets from nozzle openings. Needless to say.

The ink jet recording head of the above-described embodiment forms 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. FIG.
FIG. 2 is a schematic diagram illustrating an example of the ink jet recording apparatus.

As shown in FIG. 8, the recording head units 1A and 1B having ink jet recording heads are provided with detachable cartridges 2A and 2B constituting ink supply means.
The carriage 3 on which B is mounted is provided movably in the axial direction on a carriage shaft 5 attached to the apparatus main body 4. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

Then, 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 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 3. The platen 8 can be rotated by a driving force of a paper feed motor (not shown), and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller, is wound around the platen 8 and conveyed. It has become so.

[0098]

As described above, according to the present invention, a concave portion is provided on the joint surface of the nozzle plate with the flow path forming substrate so that an unnecessary adhesive flows into the concave portion when the nozzle plate is bonded to the flow path forming substrate. Therefore, it is possible to prevent the adhesive from flowing out into the ink flow path such as the pressure generating chamber communicating with the nozzle opening. Therefore, if such a nozzle plate is used in an ink jet recording head or the like, it is possible to prevent deterioration in characteristics due to adhesion and improve reliability.

Further, in the ink jet recording head of the present invention, the flow path forming substrate is polished to a predetermined thickness and then joined to the nozzle plate. Since the rigidity is improved, crosstalk can be prevented even if the pressure generating chambers are arranged at a relatively high density.

[Brief description of the drawings]

FIG. 1 is a 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.

FIG. 3 is a perspective view of a nozzle plate according to Embodiment 1 of the present invention.

FIG. 4 is a cross-sectional view illustrating a manufacturing process of the nozzle plate according to the first embodiment of the present invention.

FIG. 5 is a sectional view illustrating the method for manufacturing the ink jet recording head according to the first embodiment of the present invention.

FIG. 6 is a sectional view illustrating the method for manufacturing the ink jet recording head according to the first embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view showing a bonding step between the flow path forming substrate and the nozzle plate.

FIG. 8 is a schematic diagram of 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 Partition wall 12 Pressure generating chamber 20 Nozzle plate 21 Nozzle opening 22 Crater part 23 Depression 50 Elastic film 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 300 Piezoelectric element

Claims (19)

[Claims] 1. A substrate formed of a silicon single crystal substrate and having a plurality of nozzle openings for discharging liquid droplets, and bonded to a flow path forming substrate having a flow path communicating with the nozzle openings, via an adhesive. A nozzle plate, comprising: a plurality of recesses in a region to be a bonding surface with the flow path forming substrate. 2. The nozzle plate according to claim 1, wherein the recess is provided in a region facing a peripheral edge of the flow path. 3. The crater portion or the slit portion according to claim 1, wherein a portion in a thickness direction is removed in a region corresponding to the nozzle opening on a surface opposite to a bonding surface with the flow path forming substrate. A nozzle plate comprising: 4. The nozzle plate according to claim 3, wherein said concave portion and said crater portion or slit portion are formed in the same step. 5. The nozzle plate according to claim 1, wherein a main surface of the single crystal silicon substrate has a (100) orientation, and the concave portion is formed by anisotropic etching. . 6. A nozzle plate having a nozzle opening formed therein, a flow path forming substrate defining a pressure generating chamber communicating with the nozzle opening, and a region corresponding to the pressure generating chamber of the flow path forming substrate. In an ink jet recording head including a lower electrode provided via a diaphragm, a piezoelectric element including a piezoelectric layer and an upper electrode, the nozzle plate and the flow path forming substrate are joined via an adhesive, The ink jet recording head according to claim 1, wherein the nozzle plate has a plurality of concave portions in a region to be a bonding surface with the flow path forming substrate. 7. The ink jet recording head according to claim 6, wherein the recess is provided in a region of the nozzle plate facing a periphery of the pressure generating chamber. 8. An ink jet recording head according to claim 6, wherein said nozzle plate is made of a silicon single crystal substrate. 9. The ink jet recording head according to claim 8, wherein a main surface of the silicon single crystal substrate has a (100) orientation, and the concave portion is formed by anisotropic etching. 10. The nozzle plate according to claim 6, wherein a part of the nozzle plate in a thickness direction is formed in a region corresponding to the nozzle opening on a surface opposite to a bonding surface with the flow path forming substrate. An ink jet recording head having a removed crater portion or slit portion. 11. The ink jet recording head according to claim 10, wherein the concave portion of the nozzle plate and the crater portion or the slit portion are formed in the same step. 12. The ink jet recording head according to claim 6, wherein crystals of the piezoelectric layer are preferentially oriented. 13. The ink jet recording head according to claim 12, wherein the piezoelectric layer has a columnar crystal. 14. An ink jet recording head according to claim 6, wherein said piezoelectric layer has a thickness of 0.5 to 3 μm. 15. The ink jet recording head according to claim 6, wherein the array density of the pressure generating chambers is 200 dpi or more. 16. The ink jet recording head according to claim 6, wherein the thickness of the flow path forming substrate is 100 μm or less. 17. The ink jet recording head according to claim 6, wherein the flow path forming substrate is polished after forming the pressure generating chamber to have a predetermined thickness. 18. The pressure generating chamber according to claim 6, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer constituting the piezoelectric element is formed by film formation and lithography. An ink jet recording head, comprising: 19. An ink jet recording apparatus comprising the ink jet recording head according to claim 6. Description: