JP2002086722A - Ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording head and an ink jet recorder capable of increasing the number of nozzles and of eliminating crosstalk between pressurizing chambers. SOLUTION: This ink jet recording head comprises fluid passage forming substrates 10A, 10B formed of monocrystalline silicon in which the pressurizing chambers 12A, 12B communicating with the nozzles 21A, 21B are partitioned by a plurality of partition walls, piezoelectric elements 300A, 300B each consisting of a lower electrode 60, a piezoelectric layer 70 and an upper electrode 80 with a diaphragm 50 provided to one face side of each of the respective fluid passage forming substrates 10A, 10B and a nozzle plate 20 having the nozzles 21A, 21B which is bonded to the other face side of the fluid passage forming substrate 10A. The plurality of fluid passage forming substrates 10A, 10B each having the pressurizing chambers 12A, 12B, the diaphragms 50 and the piezoelectric elements 300A, 300B are laminated. An ink passage 19A for communicating the pressurizing chamber 12B provided to the other fluid passage forming substrate 10B with the nozzle 21B is provided to the fluid passage forming substrate 10A provided between the nozzle plate and the other fluid passage forming substrate 10B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate. Ink jet recording heads that eject droplets use a longitudinal vibration mode piezoelectric actuator in which piezoelectric elements expand and contract in the axial direction, and a flexural vibration mode piezoelectric actuator.
The types have been put to practical use.

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

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

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

This eliminates the need for attaching the piezoelectric element to the vibration plate, which not only allows the piezoelectric element to be manufactured by a precise and simple method such as lithography, but also reduces the thickness of the piezoelectric element. There is an advantage that it can be made thin and can be driven at high speed.

[0007]

In such an ink jet type recording head, when the pressure generating chambers are arranged at a high density, the rigidity of the partition walls becomes insufficient due to the reduced thickness of the partition walls between the pressure generating chambers. In addition, there is a problem that crosstalk occurs between the pressure generating chambers.

If the pressure generating chambers are arranged at intervals to prevent crosstalk in order to increase the number of nozzles, there is a problem that the area of the recording head becomes large.

On the other hand, in a piezoelectric actuator of the longitudinal vibration mode, a structure is considered in which a wide portion is provided on the diaphragm side of the pressure generating chamber, and the thickness of the partition wall is increased by reducing the width of the pressure generating chamber in other portions. However, in this case, there is a problem that work such as processing and bonding of a wide portion of the pressure generating chamber is required, and workability and accuracy are low.

In view of such circumstances, an object of the present invention is to provide an ink jet recording head and an ink jet recording apparatus in which the number of nozzles is increased and crosstalk between pressure generating chambers is prevented.

[0011]

According to a first aspect of the present invention, there is provided a flow path forming substrate made of single crystal silicon, wherein a pressure generating chamber communicating with a nozzle opening is defined by a plurality of partition walls. A piezoelectric element comprising a lower electrode, a piezoelectric layer and an upper electrode via a vibration plate on one side of the flow path forming substrate,
In an ink jet recording head comprising: a nozzle plate having the nozzle opening joined to the other surface side of the flow path forming substrate; a flow path forming substrate provided with the pressure generating chamber, the vibration plate, and the piezoelectric element Are laminated, and a flow path forming substrate disposed between the nozzle plate and another flow path forming substrate has a pressure generation chamber provided in the other flow path forming substrate and the nozzle opening. And an ink flow path communicating with the ink jet recording head.

According to the first aspect, the rigidity of the partition partitioning the pressure generating chamber is maintained, the crosstalk is suppressed, and the nozzle openings can be arranged at a high density.

According to a second aspect of the present invention, in the first aspect, the pressure generation chambers provided in each of the flow path forming substrates adjacent to each other are provided in regions not opposed to each other. Ink-jet recording head.

According to the second aspect, the pressure generating chambers can be arranged at a high density, and an ink flow path or the like that connects each pressure generating chamber with the nozzle opening can be easily formed.

According to a third aspect of the present invention, in the first or second aspect, the nozzle plate is provided with a plurality of rows of the nozzle openings, and the nozzle openings arranged in each row are stacked. And a pressure generating chamber provided on one of the flow path forming substrates.

In the third aspect, ink is ejected from the pressure generating chamber through the ink flow path for each row of nozzle openings.

According to a fourth aspect of the present invention, in the third aspect, the nozzle openings are provided at positions displaced in the direction in which the pressure generating chambers are arranged side by side in each of the rows. In the recording head.

In the fourth aspect, when the pressure generating chambers of the flow path forming substrates adjacent to each other are provided at positions not opposed to each other, the ink supply path for supplying ink to the ink flow paths and the pressure generating chambers and the like can be easily formed. Can be formed.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the movement of the piezoelectric element is provided to the flow path forming substrate provided on the piezoelectric element side of the adjacent flow path forming substrate. An ink jet recording head is provided with a piezoelectric element holding portion that secures a space that does not hinder the printing.

According to the fifth aspect, the flow path forming substrates can be easily laminated, and the breakage of the piezoelectric element due to the external environment can be prevented.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the flow path forming substrate other than the flow path forming substrate directly bonded to the nozzle plate includes the nozzle plate side. And a wiring connection hole for connecting an individual electrode of the piezoelectric element provided on the flow path forming substrate to an external wiring.

According to the sixth aspect, the individual wiring of the piezoelectric element can be easily and reliably taken out by the wiring connection hole.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, ink is supplied to the pressure generating chamber through the flow path forming substrate in communication with an end of the pressure generating chamber. An ink jet recording head is provided with an ink supply path.

In the seventh aspect, ink can be easily and reliably supplied to each pressure generating chamber by the ink supply path.

According to an eighth aspect of the present invention, in the seventh aspect, the ink supply path includes a reservoir of the pressure generating chamber provided in a direction in which the pressure generating chambers are arranged. Ink-jet recording head.

In the eighth aspect, the reservoir can be provided in the flow path forming substrate, and the ink from the reservoir can be reliably supplied to the pressure generating chamber even when a plurality of flow path forming substrates are stacked.

According to a ninth aspect of the present invention, in the seventh or eighth aspect, a flow path forming substrate on the nozzle plate side is provided on another flow path forming substrate other than directly bonded to the nozzle plate. And an ink supply port for communicating with the ink supply path.

In the ninth aspect, the ink can be reliably supplied to the pressure generating chamber via the ink supply path and the ink inlet.

A tenth aspect of the present invention is the ink jet recording head according to any one of the first to ninth aspects, wherein the piezoelectric element is formed by film formation and lithography.

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

An eleventh aspect of the present invention is directed to an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to tenth aspects.

According to the eleventh aspect, it is possible to realize an ink jet recording head having improved ink discharge characteristics of the head.

[0033]

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

(Embodiment 1) FIG. 1 is an exploded perspective view of an ink jet recording head according to Embodiment 1 of the present invention, FIG. 2 is a top view of a nozzle plate and respective flow path forming substrates, and FIG. FIG. 4 is a cross-sectional view taken along the line AA ′ and a cross-sectional view taken along the line BB ′ of FIG.
FIG. 3 is a cross-sectional view taken along the line CC ′ and a line DD ′ of FIG. 2.

As shown, in the present embodiment, the flow path forming substrates 10A and 10B are stacked in the thickness direction.

The flow path forming substrates 10A and 10B include:
A plurality of partition walls 11A and 11B which will be described in detail later.
The pressure generating chambers 12A and 12B defined in the piezoelectric element 3 are opposed to one side of each of the pressure generating chambers 12A and 12B.
00A and 300B are provided. Further, a nozzle plate 20 is joined to a surface of the flow path forming substrate 10A opposite to the piezoelectric element 300A.

The pressure generating chamber 12 of the flow path forming substrate 10B
B is provided in a position shifted in the width direction so as to be a region not facing the pressure generating chamber 12A of the flow path forming substrate 10A, that is, a region facing the partition 11A of the flow path forming substrate 10A. Further, the pressure generation chamber 12B is provided at a position shifted by a predetermined amount in the longitudinal direction with respect to the pressure generation chamber 12A, as will be described in detail later.

In the present embodiment, the flow path forming substrates 10A and 10B are made of a silicon single crystal substrate having a plane orientation (110), and one of the flow path forming substrates 10A and 10B is an opening surface, and the other is Has an elastic film 50 formed thereon.
The elastic film 50 includes a silicon dioxide film 51 formed on the flow path forming substrates 10A and 10B by thermal oxidation in advance, and a zirconium oxide film 52 formed thereon.

Here, the flow path forming substrate 10A to which the nozzle plate 20 is bonded will be described in detail.

The opening surface of the flow path forming substrate 10A is anisotropically etched to form pressure generating chambers 12A partitioned by a plurality of partition walls 11A and juxtaposed in the width direction, and one end of each pressure generating chamber 12A. An ink supply passage 14A for supplying ink from a reservoir (not shown) to each pressure generation chamber 12A and an ink supply passage 15A for communicating each pressure generation chamber 12A with each ink supply communication hole 14A. Have been. The elastic film 50 corresponding to each ink supply communication hole 14A is provided with an ink communication hole 16A for communicating a reservoir (not shown) with the ink supply communication hole 14A.

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

In this embodiment, the long side of each pressure generating chamber 12A is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12A is formed by etching until it reaches the elastic film 50 substantially through the flow path forming substrate 10A. Here, the elastic film 5
In the case of 0, the amount affected by the alkaline solution for etching the silicon single crystal substrate is extremely small. Each ink supply passage 15A communicating with one end of each pressure generating chamber 12A is formed shallower than the pressure generating chamber 12A.
The flow resistance of the ink flowing into A is kept constant.
That is, the ink supply path 15A etches the silicon single crystal substrate halfway in the thickness direction (half etching).
It is formed by doing. Note that the half etching is performed by adjusting the etching time.

In this embodiment, the pressure generating chamber 12A is formed such that the partition wall 11A has a width slightly larger than the width of the pressure generating chamber 12A. This is because the pressure generating chamber 12B provided in the flow path forming substrate 10B described later in detail.
Is sealed by the partition 11A of the flow path forming substrate 10A.

A nozzle plate 20 is fixed to the opening side of the flow path forming substrate 10A via an adhesive, a heat welding film or the like.

The nozzle plate 20 has a row of nozzle openings 21A communicating with each pressure generating chamber 12A corresponding to one end of each pressure generating chamber 12A, and a row of nozzle openings 21A corresponding to one end of each pressure generating chamber 12B, which will be described later. And a row of nozzle openings 21B that communicate with each other through a corresponding nozzle communication hole 19A.

The nozzle plate 20 has a thickness of, for example, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less.
For example, it is made of glass ceramics having a temperature of 2.5 to 4.5 [× 10 ⁻⁶ / ° C.] or non-rusting steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10A on one surface, and also serves as a reinforcing plate for protecting the silicon single crystal substrate from impact and external force. In addition, the nozzle plate 20
The flow path forming substrate 10A may be formed of a material having substantially the same thermal expansion coefficient. In this case, the flow path forming substrate 1
Since the deformation of the nozzle plate 20 due to heat is substantially the same as that of the nozzle plate 20A, the nozzle plate 20 can be easily joined using a thermosetting adhesive or the like.

Here, the size of the pressure generating chamber 12A for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 21A for ejecting the ink droplet are determined by the amount of the ejected ink droplet,
It is optimized according to the ejection speed and ejection frequency. For example, when recording 360 ink droplets per inch, the nozzle openings 21A need to be formed with a diameter of several tens of micrometers with high accuracy.

On the other hand, on the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10A, for example, the thickness is about 0.2 μm.
m, a piezoelectric layer 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm.
Are laminated by a process described later, and the piezoelectric element 3
00A. Here, the piezoelectric element 300A is
A portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one of the electrodes of the piezoelectric element 300A is used as a common electrode, and the other electrode and the piezoelectric layer 70 are used as a common electrode.
Are patterned for each pressure generating chamber 12A.
Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric layer 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300A and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300A. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Further, here, the piezoelectric element 300A and the elastic film 50 whose displacement is generated by driving the piezoelectric element 300A are collectively referred to as a piezoelectric actuator.

The upper electrode film 80, which is an individual electrode of the piezoelectric element 300A, is provided on a flow path forming substrate 10B described later via a lead electrode 90A extending from the upper electrode film 80 to the elastic film 50. The wiring connection hole 31B is connected to an external wiring (not shown).

The piezoelectric element 30 of the flow path forming substrate 10A
On the 0A side, in the present embodiment, on the elastic film 50, similarly to the above-described flow path forming substrate 10A, a size substantially equal to the pressure generating chamber 12A partitioned by the plurality of partition walls 11B and arranged in the width direction. Pressure generating chamber 12B and each pressure generating chamber 12B
Supply communication holes 14B corresponding to the pressure generation chambers 1
A flow path forming substrate 10B formed with an ink supply path 15B that connects the ink supply passage 2B and each ink supply communication hole 14B with a constant fluid resistance is joined.

The elastic film 50 corresponding to each ink supply communication hole 14B is provided with an ink communication hole 16B for communicating a reservoir (not shown) with the ink supply communication hole 14B. On the elastic film 50 on the side opposite to the surface, the piezoelectric element 300B including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80, and the piezoelectric element 30
There is provided a lead electrode 90B for connecting the upper electrode film 80, which is an individual electrode of 0B, to an external wiring.

The pressure generating chamber 12B of the flow path forming substrate 10B is located in a region not facing the pressure generating chamber 12A of the flow path forming substrate 10A, that is, the partition wall 1 of the flow path forming substrate 10A.
1A, the pressure generating chamber 12
B has its opening surface sealed with the surface of the flow path forming substrate 10A.

The pressure generating chamber 1 of the flow path forming substrate 10B
2B is provided at a position displaced from the pressure generating chamber 12A by a predetermined amount in the longitudinal direction. This is because, in the present embodiment, the pressure generating chamber 12B, the ink supply communication hole 14B, and the ink supply path 15B are formed to have substantially the same size as the pressure generation chamber 12A, the ink supply communication hole 14A, and the ink supply path 15A, respectively. A wiring connection hole 31B to be described later is connected to the flow path forming substrate 10B.
And the pressure generation chamber 12B, the ink supply communication hole 14B, and the ink supply path 15A cannot be provided across the wiring connection hole 31B. This is because it is necessary to displace the supply communication hole 14B in the longitudinal direction so as to be on the piezoelectric element 300A side of the wiring connection hole 31B.

The flow path forming substrate 10B has a region facing the piezoelectric element 300A, that is, the pressure generating chamber 12B.
The piezoelectric element holding portion 17B capable of sealing this space is provided on the bottom surface of the partition wall 11B that defines the above, with a space secured so as not to hinder the movement.

On the other hand, the passage forming substrate 10A is provided with a nozzle communication hole 19A for communicating one longitudinal end of the pressure generating chamber 12B of the passage forming substrate 10B with the nozzle opening 21B. The nozzle communication hole 19A is provided in the pressure generating chamber 12
A is provided outside the longitudinal end of A through the flow path forming substrate 10A by dry etching or the like.

Further, an ink inlet 3 for supplying ink from an external ink supply means in communication with each ink supply passage 14A of the flow path forming substrate 10A is provided in the flow path forming substrate 10B.
0B penetrates the flow path forming substrate 10B.

Further, in the flow path forming substrate 10B, a wiring connection hole 31B for connecting the lead electrode 90A of the flow path forming substrate 10A and the external wiring is provided through the flow path forming substrate 10B. In the present embodiment, the wiring connection hole 31 is used.
Although B is provided in the direction in which the lead electrodes 90A are arranged in parallel, that is, in the direction in which the piezoelectric elements 300A are arranged, a plurality of wiring connection holes may be provided corresponding to each lead electrode 90A. In this case, as described above, the ink supply passage 14B of the flow path forming substrate 10B and the ink supply path 1
Since 5B does not straddle the wire connection hole 31B, the pressure generating chamber 12B and the pressure generating chamber 12A can be provided at the same position in the longitudinal direction.

The ink jet recording head according to the present embodiment takes in ink from each of the ink introduction port 30B and the ink communication hole 16B connected to an external ink supply means (not shown).
After filling the inside with ink from A and 14B to the nozzle openings 21A and 21B, the pressure generating chambers 12A and 12B according to a recording signal from an external driving circuit (not shown).
A voltage is applied between the lower electrode film 60 and the upper electrode film 80 corresponding to the above, and the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed, so that each of the pressure generating chambers 12A and 12B is deformed. The internal pressure increases, and each pressure generating chamber 12
Ink droplets are ejected from nozzle openings 21A and 21B communicating with A and 12B, respectively.

Here, the manufacturing process of the ink jet recording head of this embodiment will be described. 6 and 7 are cross-sectional views of the pressure generating chambers 12A in the juxtaposition direction, and FIG. 8 is a longitudinal cross-sectional view of the pressure generating chambers 12A and 12B of the flow path forming substrates 10A and 10B. .

First, as shown in FIG. 6A, the elastic film 50 is formed on the flow path forming substrate 10A. Specifically, the wafer of the silicon single crystal substrate serving as the flow path forming substrate 10 is
Thermal oxidation is performed in a diffusion furnace at 100 ° C. to form a silicon dioxide film 51. Thereafter, a zirconium layer is formed on the silicon dioxide film 51, and thermally oxidized in a diffusion furnace at, for example, 500 to 1200 ° C. to form a zirconium oxide film 52.

Next, as shown in FIG. 6B, a lower electrode film 60 is formed over the entire surface of the flow path forming substrate 10A on the pressure generating chamber 12A side by sputtering, and is patterned into a predetermined shape.

Here, the lower electrode film 60 is provided on the elastic film 50 of the flow path forming substrate 10A in a later step.
B, the pressure generating chamber 1 of the flow path forming substrate 10B
2B, the lower electrode film 60 of the piezoelectric element 300B and the piezoelectric element 3
The lower electrode film 60A and the flow path forming substrate 1 are not short-circuited by ink filled in the pressure generating chamber 12B.
The lower electrode film 60 is formed by patterning only in the region corresponding to the piezoelectric element holding portion 17B of 0B.

The material of the lower electrode film 60 is as follows.
Platinum, iridium and the like are preferred. This is because a piezoelectric layer 70 described later formed by a sputtering method or a sol-gel method is formed.
Is from 600 to 600 ° C. in an air atmosphere or an oxygen atmosphere after film formation.
This is because it is necessary to perform crystallization by firing at a temperature of about 1000 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric layer 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to diffusion of lead oxide is small, and for these reasons, platinum and iridium are preferred.

Next, as shown in FIG. 6C, a piezoelectric layer 70 is formed. For example, in the present embodiment, a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied and dried to form a gel, and then fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. Formed by using As a material for the piezoelectric layer 70, a PZT-based material is suitable when used in an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited. For example, the piezoelectric layer 70 may be formed by a spin coating method such as a sputtering method or a MOD method (organic metal thermal coating decomposition method).

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

Next, as shown in FIG. 6D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In the present embodiment, platinum is formed by sputtering.

Next, as shown in FIG. 7A, only the piezoelectric layer 70 and the upper electrode film 80 are etched to pattern the piezoelectric element 300A.

Next, as shown in FIG. 7B, a lead electrode 90A is formed over the entire surface of the flow path forming substrate 10A, and is patterned for each piezoelectric element 300A.

The above is the film forming process. After forming the film in this manner, as shown in FIG. 8A, the silicon single crystal substrate is subjected to anisotropic etching using the above-described alkali solution to form the pressure generating chamber 12A, the ink supply passage 14A, and the ink. The supply path 15A is formed. Further, a nozzle communication hole 19A is formed in the flow path forming substrate 10A by dry etching or the like.

Thereafter, the nozzle plate 20 is joined to the opening side of the flow path forming substrate 10A, and
A of the piezoelectric element 300A side, in this embodiment, the elastic film 50
The flow path forming substrate 10B is bonded thereon.

The flow path forming substrate 10B has a piezoelectric element 300B, a pressure generating chamber 12B, an ink supply passage 14B, and an ink supply path 15B similarly to the flow path forming substrate 10A described above. That is, as shown in FIG. 8B, after the piezoelectric element 300B is formed on the flow path forming substrate 10B, the pressure generating chamber 12B, the ink supply passage 14B, and the ink supply path 15B are formed by anisotropic etching. As shown in FIG. 5B, the piezoelectric element holding portion 17
B, the ink inlet 30B and the wiring hole 31B were formed by dry etching or the like.

The pressure generating chamber 1 of the flow path forming substrate 10B
Since 2B is provided so as not to face the pressure generating chamber 12A of the flow path forming substrate 10A, that is, to face the partition wall 11A, the opening surface of the pressure generating chamber 12B is sealed by the flow path forming substrate 10A. . The method of joining the flow path forming substrate 10A and the flow path forming substrate 10B is not particularly limited, and examples thereof include anodic bonding and bonding with an adhesive.

In the ink jet recording head of the present embodiment as described above, the flow path forming substrate 10B and the pressure generating chamber 12B are formed on the surface of the flow path forming substrate 10A opposite to the nozzle plate 20. Since the joining is performed so as not to face the region 12A, the thickness of the partition walls 11A and 11B that define the pressure generating chambers 12A and 12B can be sufficiently secured, and crosstalk between the pressure generating chambers 12A and 12B can be prevented. The printing speed and the printing quality can be improved by increasing the nozzle numerical aperture without increasing the area of the ink jet recording head.

(Embodiment 2) In Embodiment 1 described above,
Although the ink jet recording head has a two-layer structure of the flow path forming substrates 10A and 10B, in the second embodiment, the flow path forming substrates are provided in three layers, and the respective flow path forming substrates are provided with reservoirs for supplying ink to the respective pressure generating chambers. This is an example.

FIGS. 9 and 10 are top views of the nozzle plate and each flow path forming substrate of the ink jet recording head according to the second embodiment. FIG. 11 is a cross-sectional view taken along the line EE ′ and a line FF ′. FIG.

As shown in the drawing, in the ink jet recording head of the present embodiment, on the piezoelectric element 300B side of the flow path forming substrate 10B, in this embodiment, on the elastic film 50, the area is opposed to the piezoelectric element 300B. A flow path forming substrate 10C having a piezoelectric element holding portion 17C capable of sealing this space is joined in a state where a space that does not hinder the movement is secured.

The flow path forming substrate 10C has a piezoelectric element 300C, a pressure generating chamber 12C, an ink flow path 15C, and a piezoelectric element holding section 17C, similarly to the flow path forming substrate 10B described above.
Are formed. The pressure generating chamber 12C is provided in a region that does not face the pressure generating chamber 12B, that is, in a region that faces the partition wall 11B.
Is sealed by. Thus, the pressure generating chamber 12C
The pressure generating chamber 12C and the pressure generating chamber 12
A is located at a position where it faces.

The flow path forming substrates 10A, 10B and 1
0C, each pressure generation chamber 1 is replaced with an ink supply communication passage.
Each of the ink supply paths 15A, 12B and 12C
A first reservoir portions 41A, 41B, and 41C that constitute a part of the reservoirs 40A, 40B, and 40C that supply ink by communicating through A, 15B, and 15C are respectively provided in parallel with the pressure generating chambers 12A, 12B, and 12C. It is provided as a long hole extending in the direction.

In the flow path forming substrate 10B, a wiring connection hole 31B for connecting the lead electrode 90A and the external wiring is provided.
A second reservoir section 42B is provided to communicate with the first reservoir section 41A and constitute a part of the reservoir 40A.

On the other hand, in the flow path forming substrate 10C, the wiring connection holes 3 communicating with the wiring connection holes 31B of the flow path forming substrate 10B are provided.
1C and the reservoir 40 in communication with the second reservoir 42B.
A third reservoir portion 42C constituting a part of A, a wiring connection hole 32C for connecting the lead electrode 90B and an external wiring,
A second reservoir 43C is provided, which communicates with the first reservoir 41B and forms a part of the reservoir 40B.

That is, the reservoir 40A composed of the first reservoir 41A, the second reservoir 42B and the third reservoir 42C, the reservoir 40B composed of the first reservoir 41B and the second reservoir 43C, and the first reservoir 41
The reservoir 40C made of C is formed of the flow path forming substrates 10A, 10C.
B and 10C.

Also, as described above, the reservoirs 40B and 40B
By providing C on the flow path forming substrates 10A, 10B and 10C, the lead electrodes 90A and 90B
It passes through the bottom of the reservoirs 41B and 41C. Therefore, in the present embodiment, a protective film such as an insulating film is provided on the lead electrodes 90A and 90B to protect the lead electrodes 90A and 90B. FIG. 11B shows an example in which a protective film 91A is provided on the lead electrode 90A.

On the other hand, nozzle communication holes 34A and 34B, which communicate one end of the pressure generating chamber 12C and the nozzle opening 21C, are provided in the flow path forming substrates 10A and 10B in the thickness direction, respectively.

In such a configuration, the pressure generating chamber 12
A, 12B, and 12C can be prevented from crosstalk, and the number of nozzles can be further increased without increasing the head area, thereby improving the printing speed and printing quality.

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

For example, in Embodiments 1 and 2 described above,
Although the flow path forming substrates 10A, 10B, and 10C are stacked in two or three layers, the present invention is not limited to this, as long as the flow path forming substrates are stacked in the same configuration as in each embodiment.

In the first embodiment, the pressure generating chamber 12A and the pressure generating chamber 12B are provided at positions shifted from each other in the width direction and the longitudinal direction. However, the present invention is not limited to this. The pressure generating chambers of the flow path forming substrate may be provided at the same position in the longitudinal direction and shifted in the width direction. In this case, the nozzle openings communicating with each pressure generating chamber are arranged in a line.

On the other hand, even when the positions of the pressure generating chambers 12A and 12B are arranged in the same manner as in the first embodiment, the positions of the nozzle openings in the arrangement direction are arranged in two rows instead of in a staggered manner depending on how the nozzle communication holes are provided. Can be arranged identically.

In the first and second embodiments described above, the pressure generation chambers of the flow path forming substrates that are stacked and adjacent to each other are formed so as not to face each other. However, the pressure generation chambers are formed shallow on the piezoelectric element side. By doing so, the piezoelectric element holding portion for holding the piezoelectric element can be provided on the side opposite to the pressure generating chamber, so that the pressure generating chambers of the flow path forming substrates adjacent to each other are provided in the region facing each other. Good.

When the pressure generating chambers of the adjacent flow path forming substrates are provided in areas facing each other, it is necessary to arrange the rows of nozzle openings at positions shifted in the longitudinal direction of the pressure generating chambers. Therefore, the number of rows of nozzle openings is equal to the number of stacked layers, and the arrangement of nozzle openings in each row is the same in terms of arrangement.

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

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

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

[0094]

As described above, in the present invention, a plurality of flow path forming substrates are laminated, and the pressure generating chamber provided on the piezoelectric element side flow path forming substrate is provided on the nozzle plate side flow path forming substrate. Since the nozzle communication hole communicating with the nozzle opening is formed, the thickness of the partition wall can be sufficiently secured, crosstalk between the pressure generating chambers can be prevented, and the area of the ink jet recording head does not increase. The printing speed and printing quality can be improved by increasing the nozzle numerical aperture.

[Brief description of the drawings]

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

FIG. 2 is a top view of a nozzle plate and each flow path forming substrate of the ink jet recording head according to the first embodiment of the present invention.

FIG. 3 is a bottom view of a nozzle plate and a flow path forming substrate of the ink jet recording head according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of the pressure generating chambers according to the first embodiment of the present invention in the direction in which the pressure generating chambers are arranged.

FIG. 5 is a longitudinal sectional view of each pressure generating chamber according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view in a direction in which pressure generating chambers are arranged in a manufacturing process of the ink jet recording head according to Embodiment 1 of the present invention.

FIG. 7 is a cross-sectional view in a direction in which pressure generating chambers are arranged, showing a manufacturing process of the ink jet recording head according to Embodiment 1 of the present invention.

FIG. 8 is a longitudinal sectional view of the pressure generating chamber showing a manufacturing process of the ink jet recording head according to the first embodiment of the present invention.

FIG. 9 is a top view of a nozzle plate and respective flow path forming substrates of an ink jet recording head according to Embodiment 2 of the present invention.

FIG. 10 is a top view of one flow path forming substrate of the ink jet recording head according to Embodiment 2 of the present invention.

FIG. 11 is a cross-sectional view in a side-by-side direction and a cross-sectional view in a longitudinal direction of a pressure generating chamber according to a second embodiment of the present invention.

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

[Explanation of symbols]

 10A, 10B, 10C Flow path forming substrate 11A, 11B, 11C Partition wall 12A, 12B, 12C Pressure generating chamber 14A, 14B Ink supply path 16A, 16B, 16C Ink communication hole 17B, 17C Piezoelectric element holding part 19A, 19B Nozzle communication hole Reference Signs List 20 nozzle plate 21A, 21B, 21C nozzle opening 30B ink inlet 31B, 31C, 32C wiring connection hole 34A, 34B nozzle communication hole 40A, 40B, 40C reservoir 41A, 41B, 41C first reservoir 42B, 43C second reservoir 42C Third reservoir section 50 Elastic film 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90A, 90B, 90C Lead electrode 91A Protective film 300A, 300B, 300C Piezoelectric element

Claims (11)

[Claims] 1. A flow path forming substrate formed of a single crystal silicon and having a pressure generating chamber defined by a plurality of partition walls and communicating with a nozzle opening, and a lower electrode disposed on one side of the flow path forming substrate via a diaphragm. An ink jet type recording head comprising: a piezoelectric element including a piezoelectric layer and an upper electrode; and a nozzle plate having the nozzle opening joined to the other surface of the flow path forming substrate. A plate and a plurality of flow path forming substrates provided with the piezoelectric elements are laminated, and the flow path forming substrate disposed between the nozzle plate and another flow path forming substrate includes the other flow path forming substrate. An ink jet recording head, comprising: an ink flow path that communicates a pressure generating chamber provided on a formation substrate with the nozzle opening. 2. The ink jet recording head according to claim 1, wherein the pressure generation chambers provided in each of the flow path forming substrates adjacent to each other are provided in regions not opposed to each other. 3. The nozzle plate according to claim 1, wherein the nozzle plate is provided with a plurality of rows of the nozzle openings.
The ink jet recording head according to claim 1, wherein the nozzle openings arranged in each row communicate with pressure generating chambers provided in any one of the stacked flow path forming substrates. 4. The method according to claim 3, wherein the nozzle opening comprises:
An ink jet recording head is provided at a position shifted in the direction in which the pressure generating chambers are arranged in each row. 5. The flow path forming substrate according to claim 1, wherein a space is provided in the flow path forming substrate provided on the piezoelectric element side of the adjacent flow path forming substrate so as not to hinder the movement of the piezoelectric element. An ink jet recording head having a piezoelectric element holding portion. 6. The flow path forming substrate according to claim 1, wherein the flow path forming substrate other than the flow path forming substrate directly bonded to the nozzle plate is provided on the flow path forming substrate on the nozzle plate side. A wiring connection hole for connecting the individual electrode of the piezoelectric element to an external wiring. 7. An ink supply path according to claim 1, wherein the flow path forming substrate is provided with an ink supply path that communicates with an end of the pressure generation chamber and supplies ink to the pressure generation chamber. An ink jet recording head. 8. The ink jet recording head according to claim 7, wherein the ink supply path includes a reservoir of the pressure generation chamber provided in a direction in which the pressure generation chambers are arranged. 9. The flow path forming substrate according to claim 7, wherein the other flow path forming substrate other than directly bonded to the nozzle plate includes:
An ink jet recording head, wherein an ink introduction port communicating with the ink supply path provided in the flow path forming substrate on the nozzle plate side is provided. 10. An ink jet recording head according to claim 1, wherein said piezoelectric element is formed by film formation and lithography. 11. An ink jet recording apparatus comprising the ink jet recording head according to claim 1.