JP2001353869A - Ink jet recording head and its fabricating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head, and its fabricating method, in which rigidity of a barrier wall between pressure generating chambers is enhanced and the pressure generating chambers can be arranged at a high density. SOLUTION: The ink jet recording head comprises a channel forming substrate 1 formed by cutting a silicon single crystal substrate of (100) face orientation into a predetermined shape, a pressure generating chamber 2 formed on the surface side of the channel forming substrate 1 and containing ink being ejected from a nozzle opening, a diaphragm 5 constituting a part of an inner wall face sectioning the pressure generating chambers 2, and a piezoelectric film 12 for varying the ink pressure in the pressure generating chamber 2 by deforming the diaphragm 5. The pressure generating chamber 2 is formed by subjecting the surface of the silicon single crystal substrate to anisotropic wet etching and the inner wall face sectioning the pressure generating chambers 2 is defined by the (111) face 6 of the silicon single crystal substrate exposed by anisotropic wet etching and the inner face 7 of the diaphragm 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type in which a vibrating plate constituting a part of an inner wall surface of a pressure generating chamber is vibrated to pressurize ink in the pressure generating chamber and discharge ink droplets from nozzle openings. The present invention relates to a recording head and a method for manufacturing the recording head.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass the nozzle opening. 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 end face of a piezoelectric element is brought into contact with a diaphragm to change the volume of a pressure generating chamber by expansion and contraction of the piezoelectric element, and a recording head suitable for high-density printing can be manufactured. On the other hand, it is necessary to perform a difficult process of cutting the piezoelectric elements into a comb-tooth shape in accordance with the arrangement pitch of the nozzle openings, and a work of positioning and fixing the cut piezoelectric elements in the pressure generating chamber, which complicates the manufacturing process. There is a problem that there is.

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, Japanese Patent Application Laid-Open No. 5-286131 discloses an example of a recording head for solving the above-mentioned disadvantages of the ink jet recording head in the flexural vibration mode. It is proposed that a uniform piezoelectric material layer be formed by film forming technology over the entire area, and this piezoelectric material layer be cut into a shape corresponding to the pressure generation chambers by lithography to form piezoelectric elements so that each pressure generation chamber is independent. Have been.

According to this, the operation of attaching the piezoelectric element to the vibration plate becomes unnecessary, and not only can the piezoelectric element be manufactured by a precise and simple method called lithography, but also the thickness of the piezoelectric element can be reduced. This has the advantage that the thickness can be reduced and high-speed driving can be performed. In addition, in such an ink jet recording head, the pressure generation chamber is formed by penetrating in the thickness direction by etching from the opposite side of the substrate from the piezoelectric element. It can be easily installed at a high density.

In manufacturing the above-mentioned conventional ink jet recording head, after a thin film actuator including a piezoelectric element is formed on the surface of a silicon single crystal substrate having a (110) plane orientation, a pressure generating chamber is formed in the silicon single crystal substrate. It was formed to penetrate from the back surface.

[0008]

However, in the above-described conventional ink jet recording head, a relatively large silicon single crystal substrate having a diameter of, for example, about 6 to 12 inches is used as the silicon single crystal substrate for forming the pressure generating chamber. In this case, the thickness of the substrate must be increased due to problems such as handling, and the depth of the pressure generating chamber also increases accordingly.

Therefore, unless the thickness of the partition walls for partitioning the pressure generating chambers is increased, sufficient rigidity cannot be obtained, crosstalk occurs, and desired discharge characteristics cannot be obtained. In addition, when the wall thickness is increased, the nozzles cannot be arranged with a high arrangement density, so that there is a problem that high-resolution printing quality cannot be achieved.

The present invention has been made in consideration of the above circumstances, and has as its object to improve the rigidity of a partition between pressure generating chambers and to arrange the pressure generating chambers at high density. And a method for manufacturing the same.

[0011]

In order to solve the above-mentioned problems, an ink jet recording head according to the present invention comprises:
00) A flow path forming substrate formed by cutting a silicon single crystal substrate having a plane orientation into a predetermined shape and including a front surface and a back surface, and ink formed on the front surface side of the flow path forming substrate and discharged from a nozzle opening A pressure generating chamber for accommodating the pressure generating chamber, a diaphragm constituting a part of an inner wall surface defining the pressure generating chamber, and a piezoelectric element that deforms the diaphragm to change the pressure of ink in the pressure generating chamber. The pressure generating chamber is formed by anisotropic wet etching of the front surface of the silicon single crystal substrate including the front surface and the back surface, and the inner wall surface defining the pressure generating chamber has the anisotropic Is formed by the (111) plane of the silicon single crystal substrate exposed by the wet etching and the inner surface of the diaphragm.

[0012] Preferably, the vibrating plate includes a first film including an inner surface of the vibrating plate constituting a part of an inner wall surface of the pressure generating chamber, and a second film formed on the first film. Having a supply hole for supplying an etching solution to the surface of the silicon single crystal substrate when forming the pressure generating chamber, wherein the first film is formed by the second film. The supply hole is closed.

Preferably, the supply hole is formed in a region facing the pressure generating chamber.

[0014] Preferably, a protective layer having an opening in a region facing the pressure generating chamber is provided on the flow path forming substrate, and the pressure generating chamber is provided through the opening of the protective layer. The flow path forming substrate is formed by etching.

Preferably, the protective layer is a polycrystalline silicon film or a silicon nitride film doped with boron.

Preferably, the supply hole is provided outside a region facing the pressure generating chamber, and
A space communicating with the supply hole is defined between the membrane and the protective layer.

Preferably, the pressure generating chamber is formed in an elongated shape, and the supply hole is formed of a slit formed along a longitudinal direction of the pressure generating chamber.

Preferably, the supply hole comprises a plurality of small holes formed in a region corresponding to a region where the pressure generating chamber is formed.

Preferably, a lower electrode film is formed on the second film, and a piezoelectric film constituting the piezoelectric element is formed on the lower electrode film.

Preferably, the second film constitutes a lower electrode film of the piezoelectric element, and a piezoelectric film constituting the piezoelectric element is formed directly on the second film.

[0021] Preferably, the first film is a silicon oxide film, a silicon nitride film or a zirconium oxide film.

Preferably, the second film is any one of a silicon oxide film, a silicon nitride film, and a zirconium oxide film, or a laminated film in which any one of the films is laminated.

Preferably, an inner surface of the diaphragm, which forms a part of an inner wall surface of the pressure generating chamber, has a convex shape toward the piezoelectric element, and the inner surface of the diaphragm has a convex shape. The vibrating plate has a convex shape corresponding to the shape toward the direction of the piezoelectric element.

Preferably, a reservoir for storing ink to be supplied to the pressure generating chamber is formed on the back side of the flow path forming substrate.

Preferably, the apparatus further comprises a nozzle plate having the nozzle openings, the nozzle plate being joined to the front surface side of the flow path forming substrate.

[0026] Preferably, a communication hole communicating the nozzle opening of the nozzle plate with the pressure generating chamber is formed in the diaphragm.

According to the present invention, there is provided an ink jet recording head which pressurizes ink in the pressure generating chamber and discharges ink droplets from nozzle openings by vibrating a diaphragm constituting a part of the inner wall surface of the pressure generating chamber. Forming a polycrystalline silicon film on the front surface of a silicon single crystal substrate having a (100) plane orientation including a front surface and a back surface;
A step of diffusing boron near the inner surfaces of the polycrystalline silicon film and the silicon single crystal substrate, leaving a region to be the pressure generating chamber; and forming a first film on the polycrystalline silicon film. Forming a supply hole for supplying an etchant to a portion where the pressure generation chamber is formed in the first film, and supplying an etchant to the portion where the pressure generation chamber is formed via the supply hole; According to the pattern of the undoped portion of the polycrystalline silicon film etched by the isotropic wet etching, the surface of the silicon single crystal substrate is etched by the anisotropic wet etching to form the pressure generating chamber. And a step of forming a second film on the first film and closing the supply hole.

According to the present invention, there is provided an ink jet recording head which pressurizes ink in the pressure generating chamber and discharges ink droplets from nozzle openings by vibrating a diaphragm constituting a part of an inner wall surface of the pressure generating chamber. In the manufacturing method, a step of forming a polycrystalline silicon film on the front surface of a silicon single crystal substrate having a (100) plane orientation including a front surface and a rear surface, and removing the polycrystalline silicon film while leaving a region serving as the pressure generating chamber Forming a polycrystalline silicon film having a predetermined pattern, forming a first film on the polycrystalline silicon film having the predetermined pattern and the surface of the silicon single crystal substrate, and forming the pressure generating chamber. Forming a supply hole for supplying an etchant to a portion to be formed in the first film, and supplying the etchant to a portion where the pressure generating chamber is to be formed via the supply hole. Then, the surface of the silicon single crystal substrate is etched by anisotropic wet etching by the predetermined pattern of the polycrystalline silicon film etched by the isotropic wet etching, thereby forming the pressure generating chamber. Forming a second film on the first film and closing the supply hole.

According to the present invention, there is provided an ink jet recording head which pressurizes ink in the pressure generating chamber and discharges ink droplets from nozzle openings by vibrating a diaphragm constituting a part of the inner wall surface of the pressure generating chamber. Forming a protective layer on the front surface of the flow path forming substrate having a (100) plane orientation including a front surface and a back surface, and forming an opening in a region of the protective layer to be the pressure generating chamber; Forming a sacrificial layer on the protective layer and patterning the sacrificial layer to leave at least a region covering the opening as a residual portion; forming a first film on the sacrificial layer; Forming a supply hole communicating with a peripheral portion of the sacrificial layer formed on the layer; and supplying an etchant through the supply hole to remove the sacrificial layer and to form the protective layer. Forming the pressure generating chamber by anisotropically etching the flow path forming substrate from the front side according to the predetermined pattern; and forming a second film on the first film to close the supply hole. And a process.

Preferably, in the step of patterning the sacrificial layer, a groove is formed around an opening of the protective layer.

Preferably, the pressure generating chamber is formed in an elongated shape, and the supply hole is formed of a slit formed along the longitudinal direction of the pressure generating chamber.

Preferably, the supply hole comprises a plurality of small holes formed in a region corresponding to a region where the pressure generating chamber is formed.

Preferably, after the supply holes are closed by the second film, a lower electrode film is formed on the second film, and a piezoelectric film and an upper electrode film are formed on the lower electrode film. Forming in a predetermined pattern.

Preferably, the second film is a lower electrode film, and after the supply hole is closed by the second film,
The method further includes forming a piezoelectric film and an upper electrode film directly on the second film in a predetermined pattern.

Preferably, the method further includes a step of forming a reservoir for storing ink to be supplied to the pressure generating chamber by wet etching before forming the lower electrode film.

Preferably, the reservoir is formed on the back side of the silicon single crystal substrate.

Preferably, after the piezoelectric film and the upper electrode film are formed, a communication hole communicating the nozzle opening and the pressure generating chamber includes the first film and the second film. The method further includes a step of forming the vibration plate.

[0038] Preferably, the first film is a silicon oxide film, a silicon nitride film or a zirconium oxide film.

Preferably, the second film is any one of a silicon oxide film, a silicon nitride film, and a zirconium oxide film, or a laminated film in which any one of the films is laminated.

Preferably, after forming the communication hole, the silicon single crystal substrate is cut into a predetermined shape to form a flow path forming substrate, and the silicon single crystal substrate is formed on the flow path forming substrate. And a step of joining a nozzle plate having the nozzle openings to the front side of the silicon single crystal substrate after or before cutting.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording head according to a first embodiment of the present invention and a method for manufacturing the same will be described with reference to the drawings.

FIG. 1 is an enlarged longitudinal sectional view showing one pressure generating chamber of the ink jet recording head according to the present embodiment and its periphery. As shown in FIG. 1, (10
0) A pressure generating chamber 2 is formed on the surface side of a flow path forming substrate 1 formed by cutting a silicon single crystal substrate having a plane orientation into a predetermined shape.

The pressure generating chamber 2 is formed by anisotropic wet etching on the surface of the silicon single crystal substrate before cutting into the flow path forming substrate 1. A polycrystalline silicon film 3 doped with boron is formed on the surface of the flow path forming substrate 1 except for a region where the pressure generating chamber 2 is formed. The upper space 4 of the pressure generating chamber 2 is a hole formed by removing a polycrystalline silicon film not doped with boron by isotropic etching. A substantially flat diaphragm 5 is formed on the upper surface of the polycrystalline silicon film 3 and above the pressure generating chamber 2 so as to cover the pressure generating chamber 2. The inner wall surface of the pressure generating chamber 2 is formed by the (111) plane 6 of the silicon single crystal substrate exposed by anisotropic wet etching and the inner surface 7 of the diaphragm 5.

The vibration plate 5 has a silicon nitride film (first film) 8 including the inner surface 7, a zirconium oxide film (second film) 9 laminated on the silicon nitride film 8, and laminated on the upper surface thereof. And the lower electrode film 11. The silicon nitride film 8 has a supply hole 10 for supplying an etchant to the surface of the silicon single crystal substrate when forming the pressure generating chamber 2, and the supply hole 10 is closed by the zirconium oxide film 9. Have been.

The lower electrode film 11 is formed on the zirconium oxide film 9.
On the lower electrode film 11, a piezoelectric film 12 constituting a piezoelectric element is formed in a predetermined pattern. An upper electrode film 13 is formed on the piezoelectric film 12.

Note that the first film made of the silicon nitride film 8 may be a silicon oxide film or a zirconium oxide film instead of the silicon nitride film. Further, the second film made of the zirconium oxide film 9 may be a silicon oxide film or a silicon nitride film instead of the zirconium oxide film, or may be made of one of a silicon oxide film, a silicon nitride film, and a zirconium oxide film. By forming the second film by a conductive film instead of the zirconium oxide film 9, the lower electrode film 11 shown in FIG. Can be used as the lower electrode film. Thereby, the manufacturing process can be simplified.

FIG. 2 is a longitudinal sectional view showing a state in which a nozzle plate 15 having nozzle openings 14 is joined to the front surface side of the flow path forming substrate 1 shown in FIG. A concave portion 16 is formed on the inner surface side of the nozzle plate 15, and the piezoelectric film 12 and the upper electrode film 13 are accommodated in the concave portion 16. The diaphragm 5 has a communication hole 17 that communicates the nozzle opening 14 of the nozzle plate 15 with the pressure generating chamber 2. A reservoir 18 for storing ink to be supplied to the pressure generating chamber 2 is formed on the back side of the flow path forming substrate 1.

Next, the method for manufacturing the ink jet recording head according to the present embodiment will be explained with reference to the drawings.

First, as shown in FIG.
0) The polycrystalline silicon film 3 is formed on the surface of the silicon single crystal substrate 20 having the plane orientation. Next, as shown in FIG. 3B, a silicon oxide film (SiO ₂ ) 21 is formed in a region to be the pressure generating chamber 2 (see FIG. 1), and the pressure generating chamber is formed using the silicon oxide film 21 as a mask. 2 is diffused in the vicinity of the polycrystalline silicon film 3 and the inner surface of the silicon single crystal substrate 20 except for the region where
Form 2 After the boron diffusion step, the silicon oxide film 21 is removed as shown in FIG.
As shown in (d), a silicon nitride film (first film) 8 having excellent etching resistance is formed on the polycrystalline silicon film 3, and a resist film 23 is formed on the silicon nitride film 8. Holes 24 are formed in the resist film 23 at positions corresponding to the supply holes 10 (see FIG. 1). By etching using the holes 24 of the resist film 23, the supply holes 10 are formed in the silicon nitride film 8 as shown in FIG.

Next, an etching solution (for example, KOH) is supplied to a portion where the pressure generating chamber 2 is to be formed through the supply hole 10. Then, as shown in FIG. 4B, first, the undoped portion of the entire polycrystalline silicon film 3 where boron is not doped is removed by isotropic wet etching. Subsequently, the pressure generating chamber 2 is formed by etching the surface of the silicon single crystal substrate 20 by anisotropic wet etching according to the removed pattern of the polycrystalline silicon film 3 in the undoped portion.

Next, as shown in FIG. 4C, a zirconium oxide film (second film) 9 is formed on the silicon nitride film 8, and the supply holes 10 are closed. Note that as a method for forming the second film, thermal oxidation, chemical vapor deposition (CVD), sputtering, or the like can be used. Next, as shown in FIG. 4D, a lower electrode film 11 is formed on the zirconium oxide film 9.

Next, as shown in FIG. 5A, a piezoelectric film 12 serving as a piezoelectric element is formed on the lower electrode film 11, and an upper electrode film 13 is formed on the piezoelectric film 12. . here,
Silicon nitride film 8, zirconium oxide film 9, and lower electrode film 11
Since the vibrating plate 5 is formed in a plate shape, the piezoelectric film 12 can be formed to a desired film thickness by a spin coating technique.

Then, as shown in FIG. 5B, a silicon oxide film 25 is formed on the upper electrode film 13 above the pressure generating chamber 2 in a predetermined pattern. By etching using the silicon oxide film 25 having the predetermined pattern as a mask, the piezoelectric film 12 and the upper electrode film 13 are processed into a predetermined pattern as shown in FIG.

The supply hole 10 may be a slit formed along the longitudinal direction at the center in the width direction of the pressure generating chamber 2 as shown in FIG.
As shown in (b), a plurality of parallel slits can be formed along the longitudinal direction. The position where the slit is formed may be inside or outside the area where the piezoelectric film 12 is projected. In addition, as shown in FIG. 6C, the supply holes 10 can be formed as a plurality of small holes formed in the region where the pressure generating chamber 2 is formed. The size and shape of the slits and small holes constituting the supply holes 10 are set so that they can be filled with the second film made of the zirconium oxide film 9.

When the second film is formed of a conductive material to form a lower electrode film, after the supply holes 10 are closed by the second film 9 (FIG. 4C), the lower electrode film 11 is formed. The step of forming (FIG. 4D) is omitted, and the piezoelectric film 12 is formed directly on the second film 9.

After forming the pressure generating chamber 2 and before forming the lower electrode film 11 (or the second film also serving as the lower electrode film), the reservoir 18 for storing the ink to be supplied to the pressure generating chamber 2 is formed. (See FIG. 2) can be formed on the back surface side of the silicon single crystal substrate 20 by wet etching. Alternatively, the pressure generating chamber 2 and the reservoir 18 can be formed in the same step. By forming the reservoir 18 by wet etching before forming the piezoelectric film 12, it is not necessary to protect the piezoelectric film 12 from an etchant.

After the piezoelectric film 12 and the upper electrode film 13 are formed, the nozzle opening 14 (see FIG. 2) and the pressure generating chamber 2 are formed.
The communication hole 17 (see FIGS. 2 and 6) for communicating the
Can also be formed. Then, after forming the communication hole 17, the silicon single crystal substrate 20 is cut into a predetermined shape to form the flow path forming substrate 1 (see FIG. 1).
Plate 1 having nozzle openings 14 on the front side of
5 are joined. Alternatively, the silicon single crystal substrate 20 and the nozzle plate 15 may be joined and then cut into a predetermined shape.

As described above, according to this embodiment,
Since the pressure generation chambers 2 are formed by anisotropic etching on the surface of the silicon single crystal substrate 20 having the (100) plane orientation, the thickness of the partition wall between the pressure generation chambers 2 can be sufficiently ensured. Even when the thickness of the substrate 20 is increased, the rigidity of the partition walls can be maintained sufficiently high, and a high-density nozzle arrangement can be realized. Further, the pressure generating chamber can be accurately formed by a simple process.

When the pressure generating chamber 2 is formed by wet etching, it is not necessary to protect the piezoelectric film 12 from an etching solution because the piezoelectric film 12 has not been formed yet.

Next, an ink jet recording head and a method of manufacturing the same according to a second embodiment of the present invention will be described with reference to the drawings. Note that the present embodiment is a partial modification of the configuration of the above-described first embodiment. Hereinafter, portions different from the first embodiment will be described.

FIG. 7 is an enlarged longitudinal sectional view showing one pressure generating chamber of the ink jet type recording head according to the present embodiment and its periphery. As in the first embodiment, FIG.
A pressure generating chamber 2 is formed on a surface side of a flow path forming substrate 1 formed by cutting a silicon single crystal substrate having a (100) plane orientation into a predetermined shape.

In this embodiment, the inner surface 7 of the vibration plate 5 forming a part of the inner wall surface of the pressure generating chamber 2 has a convex shape toward the direction of the piezoelectric film 12. The diaphragm 5 has a convex shape toward the piezoelectric film 12 corresponding to the convex shape of the inner surface of the diaphragm 5. The space 30 formed by the convex inner surface 7 is formed by injecting an etchant from the supply hole 10 and wet-etching the polycrystalline silicon film.

Further, the ink jet recording head according to the present embodiment does not include a portion corresponding to the boron-doped polycrystalline silicon film 3 (see FIG. 1) in the first embodiment. This corresponds to the space 30
This determines the etching shape of the pressure generating chamber 2.

Next, the method for manufacturing the ink jet recording head according to the present embodiment will be explained with reference to the drawings.

First, as shown in FIG. 8A,
A polycrystalline silicon film 30 is formed on the surface of a silicon single crystal substrate 20 having a (100) plane orientation. Next, as shown in FIG. 8B, a silicon oxide film (SiO ₂ ) 31 is formed in a region to be the pressure generating chamber 2 (see FIG. 7), and the silicon oxide film 31 is etched by using the silicon oxide film 31 as a mask. The crystalline silicon film 30 is removed, and a polycrystalline silicon film 30 having a predetermined pattern is formed as shown in FIG.

Next, a polycrystalline silicon film 3 having a predetermined pattern is formed.
A silicon nitride film (first film) 8 having excellent etching resistance is formed on the silicon nitride film 8 and the surface of the silicon single crystal substrate 20, and a resist film 23 is formed on the silicon nitride film 8. Holes 24 are formed in the resist film 23 at positions corresponding to the supply holes 10 (see FIG. 7). By the etching using the holes 24 of the resist film 23, the supply holes 10 are formed in the silicon nitride film 8 as shown in FIG.

Next, an etching solution (for example, KOH) is supplied to a portion where the pressure generating chamber 2 is to be formed through the supply hole 10. Then, as shown in FIG. 9C, first, the polycrystalline silicon film 30 is subjected to isotropic wet etching.
Is removed. Subsequently, the removed polycrystalline silicon film 3
With the pattern of 0, the surface of the silicon single crystal substrate 20 is etched by anisotropic wet etching to form the pressure generating chamber 2.

Next, as shown in FIG. 9D, a zirconium oxide film (second film) 9 is formed on the silicon nitride film 8, and the supply holes 10 are closed. Note that as a method for forming the second film, thermal oxidation, chemical vapor deposition (CVD), sputtering, or the like can be used. Next, as shown in FIG. 10A, a lower electrode film 11 is formed on the zirconium oxide film 9.

Next, as shown in FIG. 10B, a piezoelectric film 12 is formed on the lower electrode film 11 and the piezoelectric film 12 is formed.
An upper electrode film 13 is formed thereon. Then, as shown in FIG. 10C, a silicon oxide film 25 is formed on the upper electrode film 13 at a position above the pressure generating chamber 2 in a predetermined pattern. By etching using the silicon oxide film 25 of the predetermined pattern as a mask, as shown in FIG.
2 and the upper electrode film 13 are processed into a predetermined pattern.

When the second film is formed of a conductive material in place of the zirconium oxide film 9 and the second film is used as the lower electrode film, the supply hole 10 is closed by the second film (FIG. 9).
(D)), a step of forming the lower electrode film 11 (FIG. 10)
(A) is omitted, and the piezoelectric film 12 is formed directly on the second film.

After the pressure generating chamber 2 is formed, before forming the lower electrode film 11 (or the second film also serving as the lower electrode film), the reservoir 18 for storing the ink to be supplied to the pressure generating chamber 2 is formed. (See FIG. 2) can be formed on the back surface side of the silicon single crystal substrate 20 by wet etching. Alternatively, the pressure generating chamber 2 and the reservoir 18 can be formed in the same step. By forming the reservoir 18 by wet etching before forming the piezoelectric film 12, it is not necessary to protect the piezoelectric film 12 from an etchant.

After the piezoelectric film 12 and the upper electrode film 13 are formed, the nozzle opening 14 (see FIG. 2) and the pressure generating chamber 2 are formed.
The communication hole 17 (see FIGS. 2 and 6) for communicating the
Can also be formed. After forming the communication hole 17, the silicon single crystal substrate 20 is cut into a predetermined shape to form the flow path forming substrate 1 (see FIG. 7).
Plate 1 having nozzle openings 14 on the front side of
5 are joined.

As described above, according to this embodiment, similarly to the first embodiment, the pressure generating chamber 2 is formed by anisotropic etching on the surface of the silicon single crystal substrate 20 having the (100) plane orientation. So that the pressure generating chamber 2
It is possible to ensure a sufficient thickness of the partition between them, and even if the thickness of the substrate 20 is increased, the rigidity of the partition can be maintained sufficiently high, and a high-density nozzle arrangement can be achieved. Further, the pressure generating chamber can be accurately formed by a simple process.

When the pressure generating chamber 2 is formed by wet etching, since the piezoelectric film 12 has not been formed yet, it is not necessary to protect the piezoelectric film 12 from an etching solution.

Further, in this embodiment, the pressure generating chamber 2 is formed by wet etching using the space of the predetermined pattern formed by removing the polycrystalline silicon film 30 formed in the predetermined pattern. In addition, the boron doping step (FIG. 3B) required in the manufacturing process of the above-described first embodiment can be omitted.

Next, an ink jet recording head and a method of manufacturing the same according to a third embodiment of the present invention will be described with reference to the drawings. Note that the present embodiment is a partial modification of the configuration of the above-described first embodiment. Hereinafter, portions different from the first embodiment will be described. In addition, FIG.
FIG. 2 is an enlarged longitudinal sectional view showing one pressure generating chamber of the ink jet type recording head according to the embodiment and its surroundings.

As shown in FIG. 11, in the ink jet recording head of this embodiment, an opening 19 a is formed on the surface of the flow path forming substrate 20 in a region facing the pressure generating chamber 2, for example, made of silicon nitride. Is provided.

The supply hole 10 is provided in a region of the first film 8 which faces the peripheral portion of the pressure generating chamber 2. It is the same as the first embodiment except that a space 33 communicating with the supply hole 10 is defined between the membrane 8.

As will be described in detail later, the space 33 is formed by injecting an etchant from the supply hole 10 and removing the sacrificial layer by wet etching.

Hereinafter, the method for manufacturing the ink jet recording head according to the present embodiment will be explained with reference to the drawings.

First, as shown in FIG.
0) The protective layer 19 is formed on the surface of the flow path forming substrate 10 having the plane orientation. Next, as shown in FIG.
The region to be the pressure generating chamber 2 is removed by, for example, etching using a predetermined mask pattern to form an opening 19a.

Next, as shown in FIG. 12C, a sacrificial layer 90 made of, for example, polysilicon is formed on the protective layer 19, and is etched by using, for example, a predetermined mask pattern. , Opening 1 of protective layer 19
The area covering 9a is left as a residual portion 91. In the present embodiment, the region other than the remaining portion 91 is completely removed.

Next, as shown in FIG. 12D, a silicon nitride film (first film) 8 having excellent etching resistance is formed on the remaining portion 91 of the sacrificial layer 90 and on the surface of the flow path forming substrate 20. Is formed on the silicon nitride film 8 in the same manner as in the above-described embodiment.
The supply holes 10 are formed using a resist film or the like. Specifically, the supply hole 10 is formed in a region of the silicon nitride film 8 corresponding to the outside of the region to be the pressure generating chamber 2.

Next, an etching solution (for example, KOH) is supplied to a portion where the pressure generating chamber 2 is to be formed through the supply hole 10. Then, as shown in FIG. 12E, first, the residual portion 91 of the sacrificial layer 90 is removed by isotropic wet etching, and a space 33 is formed. As a result, the opening 19a of the protective layer 19 is formed. Is exposed. Subsequently, the surface of the flow path forming substrate 10 is etched by anisotropic wet etching through the opening 19a, and
Is formed.

Next, as shown in FIG. 12F, a zirconium oxide film (second film) 9 is formed on the silicon nitride film 8, and the supply holes 10 are closed. Note that as a method for forming the second film, thermal oxidation, chemical vapor deposition (CVD), sputtering, or the like can be used.

Thereafter, similarly to the above-described embodiment, a lower electrode film 11, a piezoelectric film 12, and an upper electrode film 13 are sequentially formed on the zirconium oxide film 9 and patterned to form a piezoelectric element. I do.

In this embodiment, as in the above-described embodiment, the thickness of the partition wall between the pressure generating chambers 2 can be sufficiently ensured, and the thickness of the flow path forming substrate 10 is increased. Even in this case, the rigidity of the partition wall can be maintained sufficiently high, and a high-density nozzle arrangement can be realized. Further, the pressure generating chamber can be accurately formed by a simple process.

In this embodiment, finally, the sacrificial layer 9 is formed.
0 is completely removed, but the present invention is not limited to this. For example, as shown in FIG. 13, a residual portion 92 that is not removed when the residual portion 91 is etched in a region outside the space portion 33. May be left. In the case of such a configuration, when patterning the sacrificial layer 90, a groove is formed over the periphery of the opening 19a to form the residual portion 91.
It is sufficient to completely separate the residual portion 92 from the residual portion 92.

FIG. 14 is a perspective view showing a schematic configuration of an ink jet recording apparatus equipped with the ink jet recording heads according to the first to third embodiments. FIG.
Reference numeral 41 denotes a carriage.
An ink jet recording head (not shown) according to the first or second embodiment is provided on the lower surface side of the ink jet recording head. The carriage 41 is configured to be reciprocated in the axial direction of the platen 45 by being guided by a guide member 44 via a timing belt 43 driven by a carriage motor 42. Here, the carriage 41 is formed of a thermoplastic resin.

The carriage 41 is provided with a black ink cartridge 47 as an ink storage section for supplying ink to the recording head and a color ink cartridge 48 in a detachable manner. The carriage 41 typically has a filtering mechanism for filtering the ink from the cartridges 47 and 48, and the filtered ink is supplied to the recording head.

A capping means 49 is disposed at a home position (right side in the figure) which is a non-printing area of the recording apparatus.
When the recording head mounted on the recording head 1 moves to the home position, the nozzle forming surface of the recording head can be sealed. A pump unit 50 for applying a negative pressure to the internal space of the capping unit 49 is disposed below the capping unit 49.

In the vicinity of the printing area side of the capping means 49, a wiping means 51 provided with an elastic plate such as rubber is arranged so as to be able to advance and retreat in a horizontal direction, for example, with respect to the movement locus of the recording head. When reciprocating to the capping means 49 side, the nozzle forming surface of the recording head can be wiped as necessary.

[0093]

As described above, according to the present invention, (1)
00) Since the pressure generating chamber is formed by anisotropic etching on the surface of the silicon single crystal substrate having the plane orientation, the thickness of the partition wall between the pressure generating chambers can be sufficiently ensured, and the thickness of the substrate can be increased. Even when the number of nozzles increases, the rigidity of the partition walls can be maintained sufficiently high, and a high-density nozzle arrangement can be realized. Further, the pressure generating chamber can be accurately formed by a simple process.

When the pressure generating chamber is formed by wet etching, there is no need to protect the piezoelectric film from the etchant because the piezoelectric film has not been formed yet.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view showing one pressure generating chamber and its periphery of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which a nozzle plate having nozzle openings is joined to the front surface side of the flow path forming substrate 1 shown in FIG.

FIG. 3 is a diagram showing a manufacturing process of the ink jet recording head according to the first embodiment of the present invention.

FIG. 4 is a view showing a manufacturing process of the ink jet recording head according to the first embodiment of the present invention, following FIG. 3;

FIG. 5 is a view showing a manufacturing step of the ink jet recording head according to the first embodiment of the present invention, following FIG. 4;

FIG. 6 is a view showing various forms of supply holes of the ink jet recording head according to the first embodiment of the present invention.

FIG. 7 is an enlarged longitudinal sectional view showing one pressure generating chamber and its periphery of an ink jet recording head according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a manufacturing process of the ink jet recording head according to the second embodiment of the present invention.

FIG. 9 is a view showing a manufacturing step of the ink jet recording head according to the second embodiment of the present invention, following FIG. 8;

FIG. 10 is a view showing a manufacturing step of the ink jet recording head according to the second embodiment of the present invention, following FIG. 9;

FIG. 11 is an enlarged longitudinal sectional view showing one pressure generating chamber and its periphery of an ink jet recording head according to a third embodiment of the present invention.

FIG. 12 is a diagram showing a manufacturing process of the ink jet recording head according to the third embodiment of the present invention.

FIG. 13 is an enlarged longitudinal sectional view showing one pressure generating chamber and its periphery in a modified example of the ink jet recording head according to the third embodiment of the present invention.

FIG. 14 is a perspective view showing a schematic configuration of an ink jet recording apparatus equipped with the ink jet recording head according to the first to third embodiments of the present invention.

[Explanation of symbols]

 Reference Signs List 1 flow path forming substrate 2 pressure generating chamber 3 polycrystalline silicon film 4, 30 upper space of pressure generating chamber 5 diaphragm 6 (111) surface of silicon single crystal substrate 7 inner surface of diaphragm 8 silicon nitride film (first film) Reference Signs List 9 zirconium oxide film (second film) 10 supply hole 11 lower electrode film 12 piezoelectric film (piezoelectric element) 13 upper electrode film 14 nozzle opening 15 nozzle plate 17 communication hole 18 reservoir 20 silicon single crystal substrate 21, 31 silicon oxide film 22 Boron diffusion region

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tetsuji Takahashi 3-5-5 Yamato, Suwa-shi, Nagano F-term in Seiko Epson Corporation (reference) 2C057 AF33 AF68 AF93 AG14 AG53 AG55 AN01 AP02 AP14 AP33 AP34 AP51 AP52 AP53 AP56 AP79 AQ02 BA03 BA14

Claims (30)

[Claims] 1. A flow path forming substrate formed by cutting a silicon single crystal substrate having a (100) plane orientation into a predetermined shape, including a front surface and a back surface, and a nozzle formed on the front surface side of the flow path forming substrate. A pressure generating chamber for accommodating ink ejected from the opening, a vibration plate constituting a part of an inner wall defining the pressure generation chamber, and changing the pressure of the ink in the pressure generation chamber by deforming the vibration plate The pressure generating chamber is formed by anisotropic wet etching of the front surface of the silicon single crystal substrate including the front surface and the back surface, and the inner wall surface that partitions the pressure generating chamber Is formed by the (111) plane of the silicon single crystal substrate exposed by the anisotropic wet etching and the inner surface of the diaphragm. The recording head. 2. The diaphragm according to claim 1, wherein the diaphragm includes a first film including an inner surface of the diaphragm that forms a part of an inner wall surface of the pressure generating chamber, and a first film formed on the first film. A supply hole for supplying an etchant to the surface of the silicon single crystal substrate when the pressure generating chamber is formed; An ink jet recording head, wherein the supply hole is closed by a film. 3. The ink jet recording head according to claim 2, wherein the supply hole is formed in a region facing the pressure generating chamber. 4. The pressure generation chamber according to claim 1, further comprising a protective layer having an opening in a region facing the pressure generation chamber, on the flow path forming substrate, An ink jet recording head formed by etching the flow path forming substrate through an opening in a protective layer. 5. The ink jet recording head according to claim 4, wherein the protective layer is a boron-doped polycrystalline silicon film or silicon nitride film. 6. The space according to claim 4, wherein the supply hole is provided outside a region facing the pressure generating chamber, and is provided between the first film and the protective layer and communicates with the supply hole. An ink jet recording head, wherein a part is defined. 7. The pressure generating chamber according to claim 2, wherein the pressure generating chamber is formed in an elongated shape, and the supply hole is formed of a slit formed along a longitudinal direction of the pressure generating chamber. An ink jet recording head characterized by the following. 8. An ink jet recording head according to claim 2, wherein said supply hole comprises a plurality of small holes formed in a region corresponding to a region where said pressure generating chamber is formed. . 9. The method according to claim 2, wherein a lower electrode film is formed on the second film, and a piezoelectric film constituting the piezoelectric element is formed on the lower electrode film. An ink jet recording head, characterized in that: 10. The piezoelectric device according to claim 2, wherein the second film constitutes a lower electrode film of the piezoelectric element, and a piezoelectric film constituting the piezoelectric element is formed directly on the second film. An ink jet recording head characterized in that: 11. The ink jet recording head according to claim 2, wherein the first film is a silicon oxide film, a silicon nitride film, or a zirconium oxide film. 12. The method according to claim 2, wherein the second film is any one of a silicon oxide film, a silicon nitride film, and a zirconium oxide film, or a laminated film in which any one of the silicon oxide film, the silicon nitride film, and the zirconium oxide film is laminated. Characteristic inkjet recording head. 13. The pressure generating chamber according to claim 1, wherein an inner surface of the vibration plate forming a part of an inner wall surface of the pressure generating chamber has a convex shape toward the direction of the piezoelectric element. An ink jet recording head, wherein the vibration plate has a convex shape toward the direction of the piezoelectric element corresponding to the convex shape of the inner surface of the vibration plate. 14. An ink jet recording apparatus according to claim 1, wherein a reservoir for storing ink to be supplied to said pressure generating chamber is formed on said back side of said flow path forming substrate. head. 15. The ink jet recording head according to claim 1, further comprising a nozzle plate having the nozzle opening, the nozzle plate being joined to the front surface side of the flow path forming substrate. 16. The ink jet recording head according to claim 15, wherein a communication hole for communicating the nozzle opening of the nozzle plate with the pressure generating chamber is formed in the vibration plate. 17. A method of manufacturing an ink jet type recording head in which a diaphragm constituting a part of an inner wall surface of a pressure generating chamber is vibrated to pressurize ink in the pressure generating chamber and discharge ink droplets from nozzle openings. Forming a polycrystalline silicon film on the front surface of a silicon single crystal substrate having a (100) plane orientation including a front surface and a back surface, and excluding a region serving as the pressure generating chamber, A step of diffusing boron near the inner surface of the silicon single crystal substrate, a step of forming a first film on the polycrystalline silicon film, and a supply hole for supplying an etchant to a portion where the pressure generating chamber is formed Forming the first film on the first film, and supplying an etchant to the portion where the pressure generating chamber is formed through the supply hole, thereby performing isotropic wet etching. A step of forming the pressure generating chamber by etching the surface of the silicon single crystal substrate by anisotropic wet etching according to a pattern of the undoped portion of the polycrystalline silicon film etched; Forming a second film and closing the supply hole. 18. A method for manufacturing an ink jet type recording head in which a diaphragm constituting a part of an inner wall surface of a pressure generating chamber is vibrated to pressurize ink in the pressure generating chamber and discharge ink droplets from nozzle openings. Forming a polycrystalline silicon film on the front surface of a silicon single crystal substrate having a (100) plane orientation including a front surface and a back surface, and removing the polycrystalline silicon film while leaving a region serving as the pressure generating chamber. A step of forming a polycrystalline silicon film having a predetermined pattern, a step of forming a first film on the polycrystalline silicon film having the predetermined pattern and the surface of the silicon single crystal substrate, and a portion for forming the pressure generating chamber Forming a supply hole for supplying an etchant to the first film, and supplying the etchant to the portion where the pressure generating chamber is to be formed via the supply hole. According to the predetermined pattern of the polycrystalline silicon film etched by the isotropic wet etching, the surface of the silicon single crystal substrate is etched by anisotropic wet etching to form the pressure generating chamber. And a step of forming a second film on the first film and closing the supply hole. 19. A method for manufacturing an ink jet type recording head in which a diaphragm constituting a part of an inner wall surface of a pressure generating chamber is vibrated to pressurize ink in the pressure generating chamber and discharge ink droplets from nozzle openings. Forming a protective layer on the front surface of the flow path forming substrate having a (100) orientation including a front surface and a rear surface, and forming an opening in a region of the protective layer to be the pressure generating chamber; Forming a sacrificial layer on the layer and patterning the sacrificial layer to leave at least a region covering the opening as a residual portion; forming a first film on the sacrificial layer; Forming a supply hole communicating with a peripheral portion of the sacrificial layer formed on the substrate; and supplying an etchant through the supply hole to remove the sacrificial layer and to form the protective layer. Forming the pressure generating chamber by anisotropically etching the flow path forming substrate from the front side according to a constant pattern, and forming a second film on the first film to close the supply hole. And a method of manufacturing an ink jet recording head. 20. The method according to claim 19, wherein in the step of patterning the sacrificial layer, a groove is formed around an opening of the protective layer. 21. The method according to claim 17, wherein
The method according to claim 1, wherein the pressure generating chamber is formed in an elongated shape, and the supply hole includes a slit formed along a longitudinal direction of the pressure generating chamber. 22. The method according to claim 17, wherein
The method according to claim 1, wherein the supply hole includes a plurality of small holes formed in a region corresponding to a region where the pressure generating chamber is formed. 23. The method according to claim 17, wherein
After the supply hole is closed by the second film, the second
Forming a lower electrode film on the film; and forming a piezoelectric film and an upper electrode film in a predetermined pattern on the lower electrode film. . 24. The method according to claim 17, wherein
The second film is a lower electrode film, and after closing the supply hole by the second film, the piezoelectric film and the upper electrode film are
A method for manufacturing an ink jet recording head, further comprising a step of directly forming a predetermined pattern on a film. 25. The method according to claim 23, further comprising, before forming the lower electrode film, forming a reservoir for storing the ink to be supplied to the pressure generating chamber by wet etching. Of producing an ink jet recording head. 26. The method according to claim 25, wherein the reservoir is formed on the back side of the silicon single crystal substrate. 27. The method according to claim 23, wherein
After the piezoelectric film and the upper electrode film are formed, a step of forming a communication hole communicating the nozzle opening and the pressure generating chamber in the diaphragm including the first film and the second film is further included. A method for manufacturing an ink jet recording head, comprising: 28. The method according to claim 17, wherein
The method according to claim 1, wherein the first film is a silicon oxide film, a silicon nitride film, or a zirconium oxide film. 29. The method according to claim 17, wherein
The method according to claim 1, wherein the second film is a silicon oxide film, a silicon nitride film, or a zirconium oxide film, or a laminated film in which any one of the silicon oxide film, the silicon nitride film, and the zirconium oxide film is laminated. 30. The method according to claim 17, wherein
After forming the communication hole, cutting the silicon single crystal substrate into a predetermined shape to form a flow path forming substrate, and before or after cutting the silicon single crystal substrate into the flow path forming substrate Bonding a nozzle plate having the nozzle openings to the front surface side of the silicon single crystal substrate.