JP3379580B2 - Ink jet recording head, method of manufacturing the same, and ink jet recording apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a vibrating plate which constitutes a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets. The present invention relates to an inkjet recording head that ejects ink droplets by a method, a method for manufacturing the same, and an inkjet recording device.

[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 built by a precise and simple method such as a lithography method, but also the thickness of the piezoelectric element can be reduced. It has the advantage that it can be made thin and can be driven at high speed.

[0007]

However, in such an ink jet recording head, when a relatively large substrate having a diameter of about 6 to 12 inches is used as the substrate for forming the pressure generating chamber, Due to a problem such as handling, the thickness of the substrate has to be increased, and the depth of the pressure generating chamber is accordingly increased. Therefore, unless the thickness of the partition that divides each pressure generating chamber is increased, sufficient rigidity cannot be obtained, crosstalk occurs, and desired ejection characteristics cannot be obtained. Also,
If the thickness of the partition wall is increased, the nozzles cannot be arranged at a high arrangement density, so that there is a problem that high resolution printing quality cannot be achieved.

Further, in such an ink jet recording head, there are problems that the number of parts is large, the assembling process is complicated, the manufacturing efficiency is low, and the cost is high. Further, although high positional accuracy is required for assembling the parts, there are also problems that the positional accuracy is low and the yield is poor because many parts are bonded via an adhesive layer.

In view of the above circumstances, the present invention provides an ink jet recording head capable of preventing crosstalk, forming with high precision, and simplifying the manufacturing process, a method of manufacturing the same, and an ink jet recording apparatus. Is an issue.

[0010]

According to a first aspect of the present invention for solving the above-mentioned problems, a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is defined by a plurality of partition walls, and the pressure generating chamber. An ink jet recording head, comprising: a piezoelectric element that is provided in a region corresponding to the pressure generating chamber via a vibration plate that forms a part of the pressure generating chamber and that causes a pressure change in the pressure generating chamber. Is a substrate having a silicon layer made of single crystal silicon on at least both surfaces of the boron-doped polysilicon layer, the pressure generating chamber is formed in one silicon layer and the boron-doped polysilicon layer An ink introducing port communicating with the pressure generating chamber is formed in the other silicon layer on the one side. In the jet type recording head.

In the first aspect, since the pressure generating chamber is formed without penetrating the flow path forming substrate, the rigidity of the partition wall partitioning the pressure generating chamber is improved and crosstalk is suppressed.

According to a second aspect of the present invention, in the first aspect, the region of the other silicon layer facing the pressure generating chamber on the side of the boron-doped polysilicon layer is doped with boron. It is a characteristic inkjet recording head.

In the second aspect, the other silicon layer can be made to have etching selectivity, and the pressure generating chamber can be easily formed.

A third aspect of the present invention is the ink jet recording head according to the first or second aspect, characterized in that the silicon layer is made of single crystal silicon having a plane orientation (100).

In the third aspect, the pressure generating chamber can be formed relatively easily and highly accurately by etching.

According to a fourth aspect of the present invention, in any one of the first and second aspects, one of the silicon layers has a plane orientation (1
00) single crystal silicon, and the other silicon layer is made of single crystal silicon having a plane orientation (110).

In the fourth aspect, the pressure generating chamber can be formed relatively easily and highly accurately by etching.

A fifth aspect of the present invention is the ink jet recording head according to the first or second aspect, characterized in that the silicon layer is made of single crystal silicon having a plane orientation (110).

In the fifth aspect, the pressure generating chamber can be formed relatively easily and highly accurately by etching.

An inkjet printer according to the sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the thickness of the boron-doped polysilicon layer is in the range of 0.1 to 3.0 μm. On the recording head.

In the sixth aspect, the boron-doped polysilicon layer can be formed in a predetermined region relatively easily and reliably.

In a seventh aspect of the present invention according to any one of the first to sixth aspects, the one silicon layer has a communicating portion through which the ink introducing port communicates, and the communicating portion and the pressure generating chamber. And an ink supply path communicating with the ink-jet recording head.

In the seventh aspect, ink is supplied from the ink introduction port to the pressure generating chamber via the communication section and the ink supply passage.

An eighth aspect of the present invention is the ink-jet recording according to the seventh aspect, characterized in that the ink communication passage is provided on the boron-doped polysilicon layer side of the one silicon layer. On the head.

In the eighth aspect, since the flow path resistance is reduced, the ink is more reliably supplied to the pressure generating chamber.

A ninth aspect of the present invention is the reservoir of the seventh or eighth aspect, wherein the communicating portion is provided in a direction in which the pressure generating chambers are arranged in parallel and supplies ink to the pressure generating chambers. The inkjet recording head is characterized by forming at least a part thereof.

In the ninth aspect, ink is supplied to each pressure generating chamber from the reservoir including the communicating portion.

In a tenth aspect of the present invention, in any one of the first to ninth aspects, the ink introducing port is provided in a direction in which the pressure generating chambers are arranged side by side, and ink is supplied to the pressure generating chambers. An inkjet recording head is characterized in that it constitutes at least a part of a supply reservoir.

In the tenth aspect, ink is supplied to each pressure generating chamber from the reservoir including the ink inlet.

According to an eleventh aspect of the present invention, in the third or fourth aspect, the side surface in the width direction of the pressure generating chamber is an inclined surface which is inclined so that the width becomes narrower toward the piezoelectric element side. It is a characteristic inkjet recording head.

In the eleventh aspect, the angle between the bottom surface of the pressure generating chamber and the side surface in the width direction is an obtuse angle, and the flow path resistance in the pressure generating chamber is suppressed.

In a twelfth aspect of the present invention according to 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 comprising 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 type recording apparatus which improves the ink ejection performance of the head and has a high density.

According to a fourteenth aspect of the present invention, a pressure generating chamber is formed in the flow path forming substrate, and a lower electrode, a piezoelectric layer and an upper electrode are formed on one side of the flow path forming substrate via a vibration plate. In the method for manufacturing an ink jet recording head for forming a piezoelectric element, a silicon single crystal substrate is provided on both surfaces of a polysilicon layer having etching selectivity by doping with boron other than the region where the pressure generating chamber is formed. A step of forming the flow channel forming substrate having a silicon layer made of, and sequentially stacking and patterning the lower electrode, the piezoelectric layer, and the upper electrode on one silicon layer side of the flow channel forming substrate via a vibration plate. And forming the piezoelectric element, and etching the other silicon layer of the flow path forming substrate until it reaches the polysilicon layer to form an ink inlet, Patterning the polysilicon layer in a region to be the pressure generating chamber via an inlet, and etching the one silicon layer using the polysilicon layer as a mask to form the pressure generating chamber. And a method for manufacturing an ink jet recording head.

In the fourteenth aspect, the flow path forming substrate can be selectively etched through the ink introduction port to form the pressure generating chamber relatively easily. Further, since the pressure generating chamber and the like can be formed by etching from the surface of the flow path forming substrate on the side opposite to the piezoelectric element, the protection of the piezoelectric layer is improved and the work efficiency is improved.

According to a fifteenth aspect of the present invention, in the step of forming the flow path forming substrate according to the fourteenth aspect, a bonding surface side of the other silicon layer with the polysilicon layer is formed.
A method of manufacturing an ink jet recording head, comprising a step of doping boron at least in a surface layer of a region facing the pressure generating chamber.

In the fifteenth aspect, when one silicon layer is etched through the ink inlet, the other silicon layer is not etched and the pressure generating chamber can be formed relatively easily. it can.

[0040]

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

(First Embodiment) FIG. 1 is an exploded perspective view showing an ink jet recording head according to a first embodiment of the present invention, and FIG. 2 is a longitudinal direction of one pressure generating chamber of the ink jet recording head. It is a figure which shows a cross-section.

As shown in the figure, the flow path forming substrate 10 comprises a polysilicon layer 18 and first and second silicon layers 12A and 12B provided on both surfaces of the polysilicon layer 18.

In one of the silicon layers forming the flow path forming substrate 10, that is, the first silicon layer 12A in the present embodiment, for example, a pressure generating chamber partitioned by a plurality of partition walls 13 by anisotropic etching. 14 are juxtaposed in the width direction. Further, a reservoir 15 serving as a common ink chamber of each pressure generating chamber 14 is formed at one longitudinal end of each pressure generating chamber 14, and one longitudinal end of each pressure generating chamber 14 and an ink supply path 16 are formed. Communicate with each other. The ink supply passage 16 is for controlling the inflow and outflow of the ink in the pressure generation chamber 14, and is formed to be narrower and shallower than the pressure generation chamber 14 in the present embodiment.

The other silicon layer, in the present embodiment, the second silicon layer 12B is connected to the reservoir 15 communicating with the pressure generating chamber 14 by penetrating the second silicon layer 12B in the thickness direction. An ink introduction port 17 for introducing ink is formed. Further, boron is doped in a region facing the pressure generating chamber 14, the reservoir 15 and the ink supply passage 16 on the side of the surface to be joined to the polysilicon layer 18 and except for a portion where the ink inlet 17 is communicated. A boron-doped silicon layer 12a is formed.

The ink inlet 17 may form a part of the reservoir 15. Further, in the present embodiment, the ink introduction port 17 communicates with the reservoir 15, but the present invention is not limited to this. For example, the reservoir 15 is not provided in the second silicon layer 12B, and pressure is generated in the ink introduction port 17. The ink introduction port 17 may also serve as a reservoir by directly communicating with the chamber 14.

In this embodiment, the first and second silicon layers 12A and 12B constituting the flow path forming substrate 10 are each made of a silicon single crystal substrate having a plane orientation (100). Therefore, the width direction side surface 14 of the pressure generating chamber 14 is
a is an inclined surface that inclines so that the width becomes narrower toward the piezoelectric element 300 side, and the flow path resistance in the pressure generating chamber 14 is suppressed.

On the other hand, these first and second silicon layers 1
In the present embodiment, in the polysilicon layer 18 sandwiched between 2A and 12B, a boron-doped polysilicon layer 18a doped with boron in a predetermined region is formed, and the boron-doped polysilicon layer 18a forms a first layer.
Etching selectivity of the pressure generating chamber 14 formed in the silicon layer 12A is provided. That is, substantially only the boron-doped polysilicon layer 18a is sandwiched between the first and second silicon layers 12A and 12B. A silicon oxide layer may be provided between the polysilicon layer 18 and the first silicon layer 12A, which makes it possible to obtain highly accurate etching selectivity of the polysilicon layer 18.

The surfaces of the first and second silicon layers 12A and 12B forming the flow path forming substrate 10 are formed by previously thermally oxidizing the first and second silicon layers 12A and 12B. Protective films 55A and 55B are respectively formed, and the protective film 55B is used for the ink introduction port 17
It is used as a mask when forming the like.
An elastic film 50 made of, for example, zirconium oxide is formed on the protective film 55A.
0 constitutes one wall surface of the pressure generating chamber 14 by its one surface.

On the elastic film 50, a lower electrode film 60 having a thickness of, for example, about 0.5 μm and a thickness of, for example, about 1 μm are provided.
The piezoelectric layer 70 and the upper electrode film 80 having a thickness of, for example, about 0.1 μm are laminated and formed in a process described later to form the piezoelectric element 300. Here, the piezoelectric element 300
Indicates 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 used.
Is patterned for each pressure generating chamber 14. 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 used as the common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as the individual electrode of the piezoelectric element 300, but there is no problem even if this is reversed due to the convenience of the drive 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 elastic film that is displaced by the driving of the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

Further, the piezoelectric element 300 of the flow path forming substrate 10
On the other hand, in the present embodiment, the piezoelectric element holding portion capable of sealing the space on the elastic film 50 and the lower electrode film 60 in a region facing the piezoelectric device 300 while ensuring a space that does not hinder its movement. A sealing plate 20 having 21 is joined.

Nozzle openings 22 communicating with the respective pressure generating chambers 14 are bored in the sealing plate 20 and also serve as nozzle plates. Further, the nozzle opening 22 and the pressure generating chamber 14 are communicated with each other via a nozzle communication hole 51 provided by removing the elastic film 50 and the lower electrode film 60. A protective film made of an insulating material may be provided on at least the surface of the lower electrode film 60 on the inner surface of the nozzle communication hole 51. This surely prevents dielectric breakdown due to ink.

The size of the pressure generating chamber 14 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 22 for ejecting the ink droplet are optimal depending on the amount of the ejected ink droplet, the ejection speed and the ejection frequency. Be converted. For example, 1
When recording 360 ink droplets per inch, it is necessary to accurately form the nozzle opening 22 with a diameter of several tens of μm.

Here, the manufacturing process of the ink jet recording head of the present embodiment, particularly the process of forming the pressure generating chamber 14 and the like in the flow path forming substrate 10 and the piezoelectric element 300 in the region corresponding to this pressure generating chamber 14. The forming process will be described. 3 to 5 are cross-sectional views of the pressure generating chamber 14 in the longitudinal direction.

First, the flow path forming substrate 10 having the first and second silicon layers is formed on both surfaces of the polysilicon layer 18.

More specifically, as shown in FIG. 3A, first, the second silicon layer 12B is formed using a mask such as an oxide film.
In a region facing the pressure generating chamber 14, the reservoir 15 and the ink supply passage 16 on the surface layer of the above, and excluding a portion communicating with the ink inlet 17, boron is doped with boron at a depth of about 1 μm, for example. The silicon layer 12a is formed. It should be noted that a boron-doped silicon layer may be provided on the entire surface of the flow path forming substrate 10 except at least a portion where the ink introduction port 17 communicates.

Next, as shown in FIG. 3B, a polysilicon layer 18 having a thickness of about 0.1 to 3 μm is formed on the second silicon layer 12B, and a pressure is generated in the polysilicon layer 18. A boron-doped silicon layer 18a is formed by doping boron in a portion other than a region to be the chamber 14, the reservoir 15, and the ink supply path 16, and a polysilicon layer 180 is formed.
To have etching selectivity.

Next, as shown in FIG. 3C, the flow path forming substrate 10 is formed by adhering a first silicon layer 12A having a thickness of, for example, about 50 μm on the polysilicon layer 18. To be done.

The method of adhering the polysilicon layer 18 and the first silicon layer 12A is not particularly limited. For example, the first silicon layer 12A is adsorbed on the polysilicon layer 18 and the temperature is about 1200.degree. It can be bonded by annealing at a high temperature. In addition, after the first silicon layer 12A is bonded, the first silicon layer 12A
May be polished to a predetermined thickness.

Next, as shown in FIG. 3D, the surface of the flow channel forming substrate 10 thus formed, that is, the first and second silicon layers 12 constituting the flow channel forming substrate 10.
The surfaces of A and 12B are thermally oxidized in a diffusion furnace at about 1100 ° C. to form protective films 55A and 55B made of silicon dioxide.

Next, as shown in FIG. 4A, the protective film 5
An elastic film 50 is formed on 5A. For example, in the present embodiment, after forming the zirconium layer on the protective film 55A,
An elastic film 50 made of zirconium oxide was obtained by thermal oxidation in a diffusion furnace at 1200 ° C.

Next, the piezoelectric element 300 is formed on the elastic film 50 in the region to be each pressure generating chamber 14.

In the process of forming the piezoelectric element 300,
First, as shown in FIG. 4B, the lower electrode film 60 is formed on the elastic film 50 by sputtering. This lower electrode film 60
Platinum, iridium, and the like are suitable as the material. 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 lower electrode film 60
The material must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. Especially, when lead titanate zirconate titanate (PZT) is used as the piezoelectric layer 70, the diffusion of lead oxide. It is desirable that there is little change in conductivity due to, and for these reasons, platinum and iridium are preferable.

Next, as shown in FIG. 4C, the piezoelectric layer 70 is formed. 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. Was formed using. As the material of the piezoelectric layer 70, a PZT-based material is suitable when it is used in an inkjet recording head. The method of forming the piezoelectric layer 70 is not particularly limited, and may be formed by a spin coating method such as a sputtering method or a MOD method (organic metal thermal coating decomposition method).

Furthermore, after forming a lead zirconate titanate precursor film by a sol-gel method, a sputtering method, a MOD 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. Good.

Next, as shown in FIG. 4D, 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. 5A, only the piezoelectric layer 70 and the upper electrode film 80 are etched to pattern the piezoelectric element 300. Further, in this embodiment,
At the same time, the lower electrode film 60 and the elastic film 50 are patterned to form a nozzle communication hole 51 that communicates the pressure generating chamber 14 with the nozzle opening 22, and the protective film 55B is patterned to a region corresponding to the ink introduction port 17. The through hole 56 is formed.

Next, as shown in FIG. 5B, the piezoelectric element 300 is formed on the surface of the lower electrode film 60 with an etching protection film 90 made of, for example, fluororesin. The etching protection film 90 is for preventing the piezoelectric layer 70 and the like from being destroyed when the pressure generating chamber 14 and the like, which will be described later, are etched.

Next, as shown in FIG. 5C, the protective film 5
The ink introduction port 17 is formed by anisotropically etching the second silicon layer 12B using 5B as a mask, for example, wet etching with an alkaline solution such as KOH. Then, the polysilicon layer 18 is patterned through the ink introduction port 17.

Here, as described above, the polysilicon layer 18 is a boron-doped polysilicon layer 18a in which a predetermined portion is doped with boron, and only the polysilicon layer 18 is selectively removed by etching. Only the boron-doped polysilicon layer 18a remains without being removed. That is, only the regions to be the pressure generating chamber 14, the reservoir 15 and the ink supply passage 16 are removed to form the penetrating portion 19 and the first silicon layer 12A is exposed. Also,
As described above, the polysilicon layer 18 is completely removed during the etching, and only the boron-doped polysilicon layer 18a remains, so that the flow path forming substrate 10 substantially includes the boron-doped polysilicon layer 18a and the first and second boron-doped polysilicon layers 18a. It will be composed of the second silicon layers 12A and 12B.

Then, as shown in FIG. 5D, the boron-doped polysilicon layer 18 constituting the flow path forming substrate 10 is formed.
The pressure generation chamber 14, the reservoir 15 and the ink supply path 16 are formed by anisotropically etching the first silicon layer 12A through the ink introduction port 17 using a as a mask. At the same time, in the present embodiment, the pressure generating chamber 14
Also, the protective film 55A in the region facing the reservoir 15 is removed by etching.

When the pressure generating chamber 14 and the like are formed by etching the first silicon layer 12A, the surface of the second silicon layer 12B on the boron-doped polysilicon layer 18a side also comes into contact with the etchant. As described above, the region of the second silicon layer 12B facing the pressure generating chamber 14 and the like is not etched because it is the boron-doped silicon layer 12a.

Here, the first silicon layer 1 of the present embodiment
Since 2A is made of a silicon single crystal substrate having a plane orientation (100) as described above, as shown in FIG. 6A, when the boron-doped polysilicon layer 18a is used as a mask for etching, the pressure generating chamber 14 and the reservoir are formed. The inner side surface that defines 15 and the ink supply path 16 is formed of the (111) plane. That is, these inner side surfaces are formed as inclined surfaces that are inclined so that the width becomes narrower toward the elastic film 50 side. For this reason,
As shown in FIG. 6B, the pressure generating chamber 14 and the reservoir 15 formed with a relatively wide width are etched until they reach the protective film 55A and the etching is stopped by the protective film 55A. The ink supply path 16 formed with a narrower width is formed shallower than the pressure generating chamber 14 because etching stops at the position where the inner side surfaces intersect each other.

Through the steps as described above, the pressure generating chamber 14 and the piezoelectric element 300 are formed, and thereafter, the piezoelectric element 30.
The etching protection film 90 provided on the surface of the film 0, etc. is removed, and the sealing plate 20 is provided on the side of the piezoelectric element 300 of the flow path forming substrate 10.
To form an ink jet recording head (see FIG. 2).
reference).

In the series of film formation and anisotropic etching steps described above, a large number of chips are formed on one wafer at the same time, and after the process is completed, one chip as shown in FIG. The chip forming flow path forming substrate 10 is divided. Then, it is fixed to a holder (not shown) or the like, mounted on a carriage, and incorporated in an inkjet recording apparatus.

In addition, the ink jet recording head of this embodiment manufactured in this way takes ink from the external ink supply means (not shown) into the reservoir 15 through the ink introduction port 17, and reaches the nozzle opening 22 from the reservoir 15. After filling the inside with ink up to and including the piezoelectric element 300 corresponding to the pressure generating chamber 14, that is, the lower electrode film 60 and the upper electrode film 80, according to the recording signal output via an external drive circuit (not shown). By applying a voltage between the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 to deform them, the pressure inside each pressure generating chamber 14 increases, and ink droplets are ejected from the nozzle openings 22.

In the ink jet recording head of this embodiment as described above, the ink inlet 17 and the pressure generating chamber 14 and the like can be collectively formed by etching, and the manufacturing efficiency is improved. Further, since the pressure generating chamber 14 and the like are formed through the ink introduction port 17 provided on the opposite side of the flow path forming substrate 10 from the piezoelectric element 300, the piezoelectric layer 70 and the like are adversely affected during etching. Can be prevented.

Further, in this embodiment, since the first and second silicon layers 12A and 12B are made of a silicon single crystal substrate having a plane orientation (100), the inner surfaces of the pressure generating chamber 14, the reservoir 15 and the ink supply passage 16 are formed. Since the (111) plane having a relatively slow etching rate appears on the surface, it is possible to accurately form the ink supply path. Therefore, the flow path resistance of the ink supplied to the pressure generating chamber 14 can be controlled with high accuracy.

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

For example, in the above-described embodiment, the first and second silicon layers 12A, 1 constituting the flow path forming substrate 10 are formed.
2B is made of a silicon single crystal substrate having a plane orientation (100), but is not limited thereto, and for example, a plane orientation (1
00) and a plane orientation (110) silicon single crystal substrate, or a plane orientation (110) silicon single crystal substrate. Of course, even with such a configuration, the same effect as described above can be obtained.

The first and second silicon layers 12A,
When 12B is made of a silicon single crystal substrate having a plane orientation (110), the inner surfaces of the pressure generating chamber 14, the reservoir 15 and the ink supply passage 16 are, as shown in FIG.
It is formed on a surface substantially perpendicular to the surface of the flow path forming substrate 10. Further, in the case of this configuration, the flow path resistance of the ink supply path 16 can be controlled by adjusting the width thereof, for example.

Further, for example, in the above-described embodiment, the nozzle opening 22 is formed in the direction perpendicular to the surface of the recording head, but the present invention is not limited to this, and for example, the nozzle opening 22 is formed on the end surface of the recording head. May be formed.

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 and, for example, 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 provided with the cartridges 2A and 2B constituting the ink supply means detachably, and the recording head units 1A and 1B are detachable.
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.

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 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 wound around the platen 8. It is designed to be transported.

[0086]

As described above, according to the present invention, since the pressure generating chamber is formed through the ink introducing port provided on the side opposite to the piezoelectric element of the flow path forming substrate, the ink introducing port and the pressure The generation chamber and the like can be collectively formed by etching, which improves the manufacturing efficiency and can prevent the piezoelectric layer and the like from being adversely affected during etching. Also, the rigidity of the flow path forming substrate is increased, and crosstalk can be prevented.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an inkjet 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 cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

FIG. 4 is a cross-sectional view showing the manufacturing process of the inkjet recording head according to the first embodiment of the invention.

FIG. 5 is a cross-sectional view showing the manufacturing process of the ink jet recording head according to the first embodiment of the invention.

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

FIG. 7 is a cross-sectional view showing an ink jet recording head according to another embodiment of the present 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 12A First silicon layer 12B Second silicon layer 13 partitions 14 Pressure generation chamber 15 Reservoir 16 ink supply path 17 Ink inlet 18 Polysilicon layer 18a Boron-doped polysilicon layer 20 sealing plate 21 Piezoelectric element holder 22 Nozzle opening 50 elastic membrane 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 300 Piezoelectric element

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Claims (15)

(57) [Claims] 1. A pressure generating chamber communicating with a nozzle opening is provided with a flow path forming substrate defined by a plurality of partition walls and a vibrating plate forming one surface of the pressure generating chamber to correspond to the pressure generating chamber. In an ink jet recording head provided with a piezoelectric element that is provided in a region to generate a pressure change in the pressure generating chamber, the flow path forming substrate has a silicon layer made of single crystal silicon on at least both surfaces of a boron-doped polysilicon layer. A substrate having, the pressure generating chamber is formed in one silicon layer and the boron-doped polysilicon layer and the other surface of the pressure generating chamber is formed of the other silicon layer,
An ink jet recording head, wherein an ink introduction port communicating with the pressure generating chamber is formed in the other silicon layer. 2. The ink jet recording head according to claim 1, wherein a region of the other silicon layer facing the pressure generating chamber on the side of the boron-doped polysilicon layer is doped with boron. 3. The ink jet recording head according to claim 1, wherein the silicon layer is made of single crystal silicon having a plane orientation (100). 4. The silicon layer according to claim 1, wherein one of the silicon layers is made of single crystal silicon having a plane orientation (100), and the other silicon layer is made of single crystal silicon having a plane orientation (110). An inkjet recording head characterized by: 5. The ink jet recording head according to claim 1, wherein the silicon layer is made of single crystal silicon having a plane orientation (110). 6. The film thickness of the boron-doped polysilicon layer according to claim 1, which is 0.1 to 3.0 μm.
Inkjet recording head characterized by being in the range of. 7. The communication section according to claim 1, wherein the one silicon layer is in communication with the ink introduction port, and an ink supply path is in communication between the communication section and the pressure generating chamber. An ink jet type recording head, further comprising: 8. The ink jet recording head according to claim 7, wherein the ink communication path is provided on the boron-doped polysilicon layer side of the one silicon layer. 9. The communication unit according to claim 7, wherein the communication portion constitutes at least a part of a reservoir that is provided in a direction in which the pressure generating chambers are arranged in parallel and supplies ink to the pressure generating chambers. Characteristic ink jet recording head. 10. The ink introducing port according to claim 1, wherein the ink introducing port is provided in at least a part of a reservoir that is provided in a direction in which the pressure generating chambers are arranged in parallel and supplies ink to the pressure generating chambers. An ink jet recording head characterized by being configured. 11. The ink jet recording head according to claim 3, wherein the side surface in the width direction of the pressure generating chamber is an inclined surface that is inclined so that the width becomes narrower toward the piezoelectric element side. 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. 14. An ink jet forming a pressure generating chamber in a flow path forming substrate and forming a piezoelectric element including a lower electrode, a piezoelectric layer and an upper electrode on one surface side of the flow path forming substrate via a vibrating plate. In a method of manufacturing a recording head, a silicon layer made of a silicon single crystal substrate is provided on both surfaces of a polysilicon layer having etching selectivity by doping with boron other than a region where the pressure generating chamber is formed. The step of forming a flow path forming substrate, and the lower electrode, the piezoelectric layer, and the upper electrode are sequentially laminated and patterned on one silicon layer side of the flow path forming substrate through a vibration plate to form the piezoelectric element. Step, and etching the other silicon layer of the flow path forming substrate until it reaches the polysilicon layer to form an ink inlet, and the pressure is applied through the ink inlet. And a step of patterning the polysilicon layer in a region to be a generation chamber and etching the one silicon layer using the polysilicon layer as a mask to form the pressure generation chamber. Manufacturing method. 15. The method according to claim 14, wherein in the step of forming the flow path forming substrate, at least a surface layer of a region facing the pressure generating chamber is on a bonding surface side of the other silicon layer with the polysilicon layer. A method for manufacturing an ink jet recording head, comprising a step of doping with boron.