JPH1158747A - Nozzle forming member, production method thereof, and ink-jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the ink resistance, ensure a high part accuracy, and achieve the mass-productivity and a low cost by forming a nozzle hole by chemical etching. SOLUTION: A nozzle forming member 60 can be obtained by forming resist patterns 63, 64 having openings 63a, 64a with the same opening size on both sides of a SUS substrate 61, penetrating the SUS substrate 61 by spraying or chemical etching, such as shower etching, or the like, from the both sides so as to form a nozzle hole 62, and peeling off the resist patterns 63, 64. As the etchant, a hydrochrolic acid liquid such as FeCl2 , or the like, is used. By forming the nozzle hole 62 by chemical etching, a nozzle forming member with a large area can be produced with a high mass-productivity at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a nozzle forming member, a method of manufacturing the same, and an ink jet head.

[0002]

2. Description of the Related Art In an ink jet recording apparatus used as an image forming apparatus such as a printer, a facsimile, a copying apparatus, etc., a plurality of nozzles for discharging ink droplets, an ink liquid chamber communicating with each nozzle, and an ink liquid in each ink liquid chamber are provided. Using an ink jet head having an energy generating means such as an electromechanical transducer or an electrothermal transducer for generating energy for discharging ink droplets from the nozzles by applying pressure to the head, the energy generating means of the head converts print data into print data. By driving in accordance with this, an ink droplet is ejected from a required nozzle to record an image.

[0003] Such an ink jet head is structurally an edge shooter type in which ink droplets are ejected from the end face side of a stack of head constituent members, and a side shooter type in which a substantially circular nozzle is formed in a nozzle forming member. And can be broadly divided into A conventional side shooter type ink jet head is disclosed in, for example,
As described in JP-A-55099, a diaphragm having a diaphragm is laminated on a piezoelectric element, and an ink liquid chamber and a liquid chamber which are pressurized by the piezoelectric element via the diaphragm on the diaphragm. There is known a configuration in which a flow path forming member that forms an ink supply path for supplying ink to the nozzles is laminated, and a nozzle forming member in which a nozzle hole is formed on the flow path forming member is further laminated.

[0004] Here, as a nozzle forming member and a method of manufacturing the same, Japanese Patent Application Laid-Open No. 1-108056 and Japanese Patent Application Laid-Open
No. 12,1842, etc., a plate made of an organic resin material having nozzle holes formed by an excimer laser, or Japanese Patent Application Laid-Open No. 63-3963.
As described in Japanese Patent Application Laid-Open No. HEI 8-139939, a resist pattern corresponding to the nozzle hole diameter is formed on an electroformed support substrate using a photosensitive resin material such as a dry film resist. There is a method of forming a nozzle plate by depositing a metal material such as nickel by electroforming using the method described above, and a method of forming a nozzle hole by pressing.

[0005]

By the way, in various recording apparatuses such as an ink jet recording apparatus, higher and higher resolutions are required, and accordingly, in an ink jet head, a nozzle of a nozzle forming member is also required. There is a demand for smaller diameter (finer) and higher precision holes.

As the above-mentioned conventional nozzle forming member which processes a resin plate using an excimer laser (or a carbon dioxide laser), it is possible to meet such demands for finer discharge ports and higher precision. 1. Due to the small one shot area, the nozzle hole diameter varies in continuous production, and the input side and output side have different shapes, and re-adhesion due to abrasion occurs.
Further, the nozzle forming member made of a resin material is easily damaged by contact with the recording paper and cleaning of the nozzle surface.
In particular, even if a water-repellent treatment is performed, its durability and reliability are not sufficient.

Further, in a method of manufacturing a nozzle forming member by combining a photolithography step and an electroforming method, the photolithography process is composed of a number of steps as is well known, and the entire processing time is long. Usually, a large number of components are imposed on a single board to mount a large number of components to reduce the cost of each component.
In a component such as a multi-nozzle head, in which a large number of channels are integrally formed, the size of one component becomes large and the number of impositions is reduced, so that the scale effect cannot be sufficiently obtained and cost reduction cannot be achieved. Further, in the electroforming method, N
i Particles and shape defects, dust, current density distribution, pH and its fluctuation, generation of crystallinity and shape defects due to additives, etc.
It is difficult to fix the conditions, and it is difficult to stably obtain a high quality nozzle forming member.

Further, since a plating film is formed after patterning a resist pattern on the electroformed support substrate, contamination in a photolithography process, for example, a resist residue, a thermal oxide film on an exposed surface of the substrate due to heat treatment during the process, etc. are formed. As a result, film defects such as a non-uniform layer of the plating film growth and pinholes are liable to occur, the yield is reduced, and the inspection cost is increased. As described above, it is difficult to reduce the cost in terms of the occurrence of pinhole defects due to contamination in the photolithography process and the thermal oxide film.

In the case of using a press, the number of press pins is about 1 to 5 and the durability is limited to 20 to 50 shots, so that the cost is increased and the multi-nozzle cannot be used. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a high ink resistance, high component accuracy, high productivity and low cost, a nozzle forming member, a method of manufacturing the same, and an ink jet head. The purpose is to provide.

[0011]

According to a first aspect of the present invention, there is provided a nozzle forming member having a nozzle hole for discharging ink droplets, wherein the nozzle hole is formed by chemical etching. Configuration.

According to a second aspect of the present invention, in the nozzle forming member of the first aspect, the nozzle hole is formed by anisotropic etching.

According to a third aspect of the present invention, in the nozzle forming member according to the first or second aspect, the inside of the nozzle hole has a nozzle opening having a large diameter on the ink liquid chamber side and a predetermined diameter on the ink jetting surface side. Configuration.

According to a fourth aspect of the present invention, in the nozzle forming member according to any one of the first to third aspects, a nozzle opening having a predetermined diameter is formed by press working on the ink ejection surface side of the nozzle hole. And

According to a fifth aspect of the present invention, in the nozzle forming member according to any one of the first to fourth aspects, the surface property of the ink jetting surface is set to a roughness of Rmax = 0.01 to 1 μm. .

According to a sixth aspect of the present invention, there is provided a method of manufacturing a nozzle forming member.
In the method for manufacturing a nozzle forming member having a nozzle hole for discharging ink droplets, the nozzle hole is formed by performing anisotropic etching on the substrate using both chemical etching and an electric field.

According to a seventh aspect of the present invention, there is provided an ink jet head having a plurality of nozzle holes for discharging ink droplets, an ink liquid chamber communicating with each nozzle hole, and an energy generating means for pressurizing the ink in the ink liquid chamber. In the head, the nozzle forming member for forming the nozzle hole is the nozzle forming member according to any one of claims 1 to 5.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an ink jet head to which the present invention is applied, FIG. 2 is an enlarged cross-sectional view of a main part of the head in a direction orthogonal to a channel direction (nozzle arrangement direction), and FIG. It is an expanded sectional view.

This ink jet head includes a drive unit 1, a liquid chamber unit 2, and a head cover 3. The drive unit 1 has a plurality of laminated piezoelectric elements 12 as energy generating elements arranged in two rows on a ceramic substrate, for example, an insulating substrate 11 such as barium titanate, alumina, or forsterite, and joined. The frame member (support) 13 made of resin, ceramic, or the like surrounding the periphery of each of the two rows of piezoelectric elements 12 is bonded to the adhesive 1.
4 joined together.

The plurality of piezoelectric elements 12 are provided between piezoelectric elements 17 (to be referred to as "driving units") to which driving pulses for applying ink to form droplets and fly. A piezoelectric element (hereinafter, referred to as a “non-driving unit”) serving as a liquid chamber support member that is located and receives a driving pulse and simply fixes the liquid chamber unit 2 to the substrate 11.
... are alternately configured.

Here, as the piezoelectric element 12, a laminated piezoelectric element having ten or more layers is used. This laminated piezoelectric element has a thickness of 10 to 50 μm / 1, for example, as shown in FIG.
Layer of lead zirconate titanate (PZT) 20 and a thickness of several μ
An internal electrode 21 made of silver / paradium (AgPd) of m / 1 layer is alternately laminated, but the material used for the piezoelectric element is not limited to the above, and other electromechanical conversion elements may be used. Can also.

The internal electrodes 21 of each piezoelectric element 12 are left and right end electrodes 22 and 23 made of AgPd every other layer (the opposing surfaces of the two piezoelectric element rows are end electrodes 22 and the non-opposing surfaces are end electrodes. 23). On the other hand, as shown in FIG.
Each pattern of the common electrode 24 and the individual electrode 25 is provided by Au plating, AgPt paste printing, AgPd paste printing, or the like.

The opposite end face electrodes 22 of each row of the piezoelectric elements 12 are connected to the common electrode 24 via a conductive adhesive 26.
On the other hand, the non-opposing end surface electrodes 23 of the piezoelectric elements 12 in each row are connected to the individual electrodes 25 via the conductive adhesive 26 in the same manner. Thereby, the driving unit 17
When a drive voltage is applied to the drive unit 17, an electric field is generated in the stacking direction, and the driving unit 17 is displaced in the stacking direction (d 33).
Direction displacement) occurs. As shown in FIG. 2, the common electrode 24 has a hole 13a formed in the frame member 13.
By filling the inside with the conductive adhesive 26, the pattern connected to each piezoelectric element is conducted.

On the other hand, the liquid chamber unit 2 includes a diaphragm 31 having a multilayer structure composed of a laminate of metal thin films and a liquid chamber partition member having a two-layer structure composed of a photosensitive resin layer composed of dry film resist (DFR). 32 and a nozzle plate 33, which is a nozzle forming member, are sequentially laminated and formed by heat fusion. By each of these members, one piezoelectric element 12
(Driving unit 17), a diaphragm 34 corresponding to the one piezoelectric element 12, a pressurized liquid chamber 35 pressurized through each diaphragm 34, and both sides of the pressurized liquid chamber 35. Common liquid chambers 36, 36 for introducing ink to be supplied to the pressurized liquid chamber 35, and the pressurized liquid chamber 35 and the common liquid chambers 36, 36.
Ink supply paths 37, 37 communicating with the pressure liquid chamber 35.
One channel is formed by the nozzle 38 communicating with the nozzle, and a plurality of channels are provided in two rows.

The diaphragm 31 is made of a nickel plating film having a two-layer structure, and is formed integrally with the diaphragm portion 34 corresponding to the driving portion 17 and at the center of the diaphragm portion 34 for joining with the driving portion 17. Corresponding to the island-shaped convex portion 40, the partition wall portion 41 which becomes a beam to be joined to the non-driving portion 18 and makes each channel (nozzle) independent, the peripheral thick portion 42 to be joined to the frame member 13, and the common liquid chamber 36. Elastic part (hereinafter referred to as "damper part") that absorbs the pressure of
43 are formed. Here, the thickness of the diaphragm portion 34 and the damper portion 43 is defined as the thickness of the first layer (first layer plating film), and the island-shaped convex portion 40, the partition wall portion 41, and the peripheral thick portion 42 are provided.
Is the thickness obtained by adding the thickness of the first layer and the thickness of the second layer (second-layer plating film).

The liquid chamber partition member 32 is formed by applying a dry film resist on the diaphragm 31 side in advance, exposing it using a required mask, and developing it to form a first liquid chamber pattern.
The photosensitive resin layer 45 and the second photosensitive resin layer 46 on which a dry film resist is applied in advance on the nozzle plate 33 side, exposed using a required mask, and developed to form a predetermined liquid chamber pattern are heated. It is joined by crimping.

The nozzle plate 33 has a large number of nozzle holes 38 which are fine discharge ports for ejecting ink droplets. Internal shape (inner shape) of this nozzle hole 38
Is formed in a horn shape. In addition, this nozzle hole 3
The diameter of 8 is about 10 to 5 on the ink drop outlet side (ink ejection surface).
It is set in the range of 0 μm.

As shown in FIG. 1, a water-repellent surface treatment film 47 is formed on the ink jetting surface (nozzle surface side) of the nozzle plate 33. The periphery of the nozzle plate 33 is a non-water-repellent surface 48 on which no water-repellent film is formed.

The drive unit 1 and the liquid chamber unit 2
After processing and assembling separately, the vibration plate 31 of the liquid chamber unit 2 and the piezoelectric element 12 and the frame member 13 of the drive unit 1 are joined with an adhesive 49.

The substrate 11 is supported and held on a spacer member (head holder) 50 serving as a head support member.
C and the electrodes 24 and 25 connected to the piezoelectric elements 12 (drive unit 17) of the drive unit 1
They are connected via PC cables 51,51.

A nozzle cover (head cover) 3
Is formed in a box shape to cover the peripheral portion of the nozzle plate 33 and the side surface of the head. An opening is formed corresponding to the water-repellent surface 47 of the nozzle plate 33, and is left at the peripheral portion of the nozzle plate 33. The non-water-repellent surface 48 is adhesively bonded with an adhesive. Further, in order to supply ink from an ink cartridge (not shown) to the liquid chamber, the ink supply holes 52 are provided in the spacer member 50, the substrate 11, the frame member 13 and the vibration plate 31, respectively.
To 55 are provided.

In the ink jet head configured as described above, by applying a drive waveform (pulse voltage of 10 to 50 V) to the drive unit 17 in accordance with the recording signal, a displacement in the stacking direction occurs in the drive unit 17, Diaphragm 31
The pressurized liquid chamber 35 is pressurized via the diaphragm portion 34 of the above, and the pressure is increased, and ink droplets are ejected from the nozzle holes 38. At this time, ink flows also in the direction of the ink supply passages 37, 37 leading from the pressurized liquid chamber 35 to the common liquid chamber 36. However, by reducing the cross-sectional area of the ink supply passages 37, 37, the fluid resistance portion is reduced. Function to reduce the flow of ink toward the common liquid chambers 36, 36, thereby preventing a drop in ink ejection efficiency.

Then, with the end of the ejection of the ink droplets, the ink pressure in the pressurized liquid chamber 35 decreases, and a negative pressure is generated in the pressurized liquid chamber 34 due to the inertia of the ink flow and the discharge process of the drive pulse. To the ink filling process. At this time, the ink supplied from the ink tank flows into the common liquid chambers 36, 36, and from the common liquid chambers 36, 36 to the ink supply paths 37, 3.
After that, it is filled into the pressurized liquid chamber 35. Then, when the vibration of the ink meniscus surface near the outlet of the nozzle hole 38 is attenuated and returned to the vicinity of the outlet of the nozzle hole 38 due to surface tension (refill) and a stable state is reached, the next ink droplet ejection operation is started.

Next, the nozzle forming member and its manufacturing method will be described with reference to FIGS. FIG. 4 is a cross-sectional view showing a first embodiment of the nozzle forming member according to the present invention, and FIG. The nozzle forming member 60 of this embodiment is made of a SUS substrate 6 such as SUS304 having a thickness of about 80 to 100 μm.
In FIG. 1, a nozzle hole 62 is formed by isotropic etching.

As shown in FIG. 5A, the nozzle forming member 60 forms resist patterns 63 and 64 having openings 63a and 64a having the same opening diameter (for example, φ20 to 60 μm) on both surfaces of the SUS substrate 61. As shown in FIG. 3B, the nozzle pattern 62 is formed by performing chemical etching such as spraying or shower etching from both sides of the SUS substrate 61 to penetrate the SUS substrate 61 to form a nozzle hole 62. Then, as shown in FIG. By peeling, the nozzle forming member 60 is obtained. Note that an acid solution of hydrochloric acid such as FeCL2 is used as an etchant.

By forming the nozzle holes by chemical etching as described above, a large-area nozzle forming member can be manufactured with high mass productivity, and the cost can be reduced. Although a SUS substrate is used here, another metal substrate that can be etched can also be used.

Next, FIG. 6 is a sectional view showing a second embodiment of the nozzle forming member according to the present invention, and FIG. 7 is an explanatory diagram for explaining a method of manufacturing the nozzle forming member of the same embodiment. In the nozzle forming member 66 of this embodiment, a nozzle hole 62 is formed on a SUS substrate 61 such as SUS304 having a thickness of about 80 to 100 μm by anisotropic etching.

As shown in FIG. 7A, the nozzle forming member 66 forms resist patterns 63 and 64 having openings 63a and 64a having the same opening diameter (for example, φ20 to 60 μm) on both surfaces of the SUS substrate 61. As shown in FIG. 3B, a nozzle hole 67 is formed by performing chemical etching such as spraying or shower etching from both sides of the SUS substrate 61 to penetrate the SUS substrate 61.

Here, by connecting a cathode in the etchant and applying an electric current of about 0.5 to 1 A / dm ² to form an electric field, chemical etching such as spraying or shower etching is usually performed to thereby reduce the electric field. .
SUS304 etch rate of 5 to 2 μm / min is 1
５5 μm / min, a pattern having strong anisotropic etching, and the nozzle hole 67 can be formed in a straight shape.

Thereafter, as shown in FIG. 3C, the resist pattern is peeled off, whereby the nozzle forming member 66 is obtained.

As shown in FIG. 4, it is difficult to form the nozzle hole in a straight shape by the isotropic etching, as shown in FIG. It can be straight.

Next, FIG. 8 is a sectional view showing a third embodiment of the nozzle forming member according to the present invention, and FIG. 9 is an explanatory diagram for explaining a method of manufacturing the nozzle forming member of the same embodiment. The nozzle forming member 71 of this embodiment has a nozzle hole 72 having a large diameter on the ink liquid chamber side and a predetermined diameter opening 72a on the ink jetting surface side by chemical etching on a SUS substrate 61 such as SUS304 having a thickness of about 80 to 100 μm. Is formed.

As shown in FIG. 9A, the nozzle forming member 71 forms a resist pattern 73 having a small-diameter opening 73a on the ink jetting surface side of the SUS substrate 61 and a large-diameter resist pattern on the ink liquid chamber surface side. A resist pattern 74 having an opening 74a is formed, and as shown in FIG.
After performing chemical etching (in this case, isotropic etching) by spraying or shower etching from both surfaces of No. 1 to penetrate and form a nozzle hole 72, a resist pattern is formed as shown in FIG. By peeling, the nozzle forming member 71 is obtained.

When a photograph is taken with the depth of focus adjusted to the plane of FIG. 8 of the nozzle forming member 71, the shape shown in FIG. 10 is obtained.
When the photograph was taken with the depth of focus adjusted to the plane of, it was confirmed that the shape was as shown in FIG.

By forming a nozzle hole having a large diameter on the ink liquid chamber side and an opening having a predetermined diameter on the ink jetting surface side, pressure waves can be concentrated on the nozzle opening.
A highly energy efficient nozzle forming member can be obtained.

Here, although isotropic etching is performed, anisotropic etching is performed in combination with an electric field as described above, so that a large-diameter opening (ink liquid chamber side) is moved to a small-diameter opening (ink ink). It is possible to form a nozzle hole having a straight taper toward the ejection surface side).

Next, FIG. 12 is a sectional view showing a fourth embodiment of the nozzle forming member according to the present invention, and FIG. 13 is an explanatory diagram for explaining a method of manufacturing the nozzle forming member of the same embodiment. The nozzle forming member 75 of this embodiment has a thickness of 80 to 100 μm.
An opening 76a having a predetermined diameter is formed by press working on the ink jetting surface side of a SUS substrate 61 such as SUS304 having a diameter of about m, and a nozzle hole 76 having a large diameter is formed by isotropic etching on the ink liquid chamber side. I have.

This nozzle forming member 75 is shown in FIG.
As shown in (1), the ink ejection surface side of a SUS substrate 61 having a thickness of, for example, 100 μm is covered with a resist pattern 77, and a resist pattern 78 having a large-diameter (for example, φ150 μm) opening 78 a is formed on the ink liquid chamber side. After the hole 79 is formed to a required depth (for example, 70 to 80 μm) by performing isotropic etching from the ink liquid chamber side as shown in FIG. A die 80 having a hole of a predetermined diameter is disposed on the ejection surface side, and a portion not penetrated by etching is punched from the ink liquid chamber side through a hole 79 by a press pin (punch) 81 to open a nozzle opening 76a. Form.

By forming the nozzle opening on the nozzle ejection surface side by press working in this way, a highly accurate nozzle hole can be formed. Since the portion formed by the press working is thinned by the etching, the wear of the press pin is reduced, and a highly accurate nozzle hole can be obtained with good mass productivity.

Next, FIG. 14 is a cross-sectional view showing a fifth embodiment of the nozzle forming member according to the present invention, and FIG. 15 is an explanatory diagram for explaining a method of manufacturing the nozzle forming member of the same embodiment. As the nozzle plate 33 of the ink jet head, a nozzle plate having a surface treatment film formed on the nozzle forming member according to the fifth embodiment is used. The nozzle forming member 85 of this embodiment is made of SUS3 having a thickness of about 80 to 100 μm.
An opening 86a having a predetermined diameter is formed by press working on the ink jetting surface side of the SUS substrate 61 such as the SUS substrate 04, and a nozzle hole 86 having a large diameter opening on the ink liquid chamber side by anisotropic etching.

As shown in FIG. 15A, the nozzle forming member 85 is, for example, 100 μm as shown in FIG.
The SUS substrate 61 having a thickness of m is coated with a resist pattern 87 on the ink ejection surface side, and a large diameter (for example, φ1
Resist pattern 88 having opening 88a of 50 μm)
After forming a hole 89 to a required depth (for example, 70 to 80 μm) by performing anisotropic etching from the ink liquid chamber side as shown in FIG. A die 8 having a hole of a predetermined diameter on the ink ejection surface side as shown in c)
0 and a press pin (punch) 8 from the ink liquid chamber side.
A portion which is not penetrated by etching through the hole 89 is perforated by 1 to form a nozzle opening 86a.

Here, the surface property of the nozzle forming member in each of the above embodiments will be described. When forming a nozzle hole by chemical etching using a metal substrate such as a SUS substrate, the surface smoothness is reduced when forming a photolithographic pattern. Surface roughness is less than Rmax = 1 μm, preferably Rmax
= 0.6 μm or less.

In this case, if the surface of the SUS substrate is rough as shown in FIG. 16, when the nozzle holes are formed by etching, φ2 μm to 3 μm as shown by arrows in FIG.
m particulate protrusions are generated at a plurality of locations, and the edge defects of the nozzle holes are likely to occur.

Therefore, the surface property of the SUS substrate is Rmax
= 0.01 to 1 μm. Rmax = 1
When the thickness exceeds μm, irregular reflection during exposure when forming a resist pattern is increased, resulting in pattern deformation. In addition, during chemical etching, there is a shape dependency (etch rate, uneven flow of etchant liquid) and deformation of the etching pattern. Is more likely to occur. A nozzle forming member having a high-precision nozzle hole in which the fluctuation of the process conditions of the surface in the photolithography process and the etching process is reduced, the nozzle edge defect is extremely reduced, and the ink ejection characteristics are stabilized by the above surface roughness. Can be obtained.

In the above embodiment, an example was described in which the present invention was applied to a piezo actuator type ink jet head using a piezoelectric element as an energy generating means and a nozzle forming member thereof, but other electromechanical conversion elements are used. The present invention can also be applied to an inkjet head and its nozzle forming member, a so-called bubble jet type inkjet head using a heating resistor, and its nozzle forming member. Also, a side shooter type ink jet head in which the opening direction of the nozzle is the same as the displacement direction of the piezoelectric element has been described, but an edge shooter type ink jet in which the nozzle opening direction is a direction orthogonal to the displacement direction of the piezoelectric element. The present invention can be applied to a head and a nozzle forming member thereof.

[0056]

As described above, according to the nozzle forming member of the first aspect, since the nozzle holes are formed by chemical etching, high ink resistance, high component accuracy can be ensured, and mass productivity is improved. Cost reduction can be achieved.

According to the nozzle forming member of the second aspect, since the nozzle hole is formed by anisotropic etching in the nozzle forming member of the first aspect, a straight nozzle hole can be formed. The accuracy of the ink ejection direction is increased.

According to the nozzle forming member of the third aspect, in the nozzle forming member of the first or second aspect, the inside of the nozzle hole has a nozzle opening having a large diameter on the ink liquid chamber side and a predetermined diameter on the ink jetting surface side. Accordingly, the pressure generated in the ink liquid chamber can be concentrated toward the nozzle opening, and the energy efficiency can be improved.

According to the nozzle forming member of the fourth aspect, in the nozzle forming member of any one of the first to third aspects,
Since a nozzle opening having a predetermined diameter is formed by press working on the ink ejection surface side of the nozzle hole, a nozzle hole having a highly accurate hole diameter can be formed.

According to the nozzle forming member of the fifth aspect, in the nozzle forming member of any one of the first to fourth aspects,
Since the surface property of the ink jetting surface side is made to have a roughness of Rmax = 0.01 to 1 μm, it is possible to suppress the fluctuation of the process condition of the surface in the etching process and to obtain a nozzle forming member having a stable ink jetting characteristic. Can be.

According to the method of manufacturing a nozzle forming member of the sixth aspect, in the method of manufacturing a nozzle forming member having a nozzle hole for discharging ink droplets, the substrate is subjected to anisotropic etching by using both chemical etching and an electric field. Therefore, a straight nozzle hole can be easily formed by anisotropic etching.

According to a seventh aspect of the present invention, there is provided an ink jet head comprising a plurality of nozzle holes for discharging ink droplets, an ink liquid chamber communicating with each nozzle hole, and energy generating means for pressurizing the ink in the ink liquid chamber. In the ink jet head, the nozzle forming member for forming the nozzle hole is the nozzle forming member according to any one of claims 1 to 5, so that the ink jet head has low cost, high nozzle diameter accuracy, and ink resistance. Can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an inkjet head to which the present invention has been applied.

FIG. 2 is an enlarged sectional view of a main part of the head in a direction orthogonal to a channel direction.

FIG. 3 is an enlarged sectional view of a main part of the head in a channel direction.

FIG. 4 is a sectional view showing a first embodiment of a nozzle forming member according to the present invention.

FIG. 5 is an explanatory diagram for explaining the method for manufacturing the nozzle forming member of the embodiment.

FIG. 6 is a sectional view showing a second embodiment of the nozzle forming member according to the present invention.

FIG. 7 is an explanatory view for explaining the method for manufacturing the nozzle forming member of the embodiment.

FIG. 8 is a sectional view showing a third embodiment of the nozzle forming member according to the present invention.

FIG. 9 is an explanatory view for explaining the method for manufacturing the nozzle forming member of the embodiment.

FIG. 10 is an explanatory diagram illustrating a state when a photograph is taken with the depth of focus adjusted to the plane of FIG. 8;

11 is an explanatory diagram illustrating a state when a photograph is taken with the depth of focus adjusted to the plane of FIG. 8;

FIG. 12 is a sectional view showing a fourth embodiment of the nozzle forming member according to the present invention.

FIG. 13 is an explanatory diagram which is used for describing the method for manufacturing the nozzle forming member of the embodiment.

FIG. 14 is a sectional view showing a fourth embodiment of the nozzle forming member according to the present invention.

FIG. 15 is an explanatory view serving to explain a method of manufacturing the nozzle forming member of the embodiment.

FIG. 16 is an explanatory diagram for explaining the relationship between the surface roughness of a substrate and edge droop;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive unit, 2 ... Liquid chamber unit, 12 ... Piezoelectric element, 33 ... Nozzle plate, 38 ... Nozzle hole, 38a ...
Nozzle openings, 60, 66, 71, 75, 85 ... Nozzle forming member, 61 ... SUS substrate, 62, 67, 72, 76,
86 ... nozzle holes, 72a, 76a, 86a ... nozzle openings.

Claims (7)

[Claims] 1. A nozzle forming member having a nozzle hole for discharging ink droplets, wherein the nozzle hole is formed by chemical etching. 2. The nozzle forming member according to claim 1, wherein said nozzle hole is formed by anisotropic etching. 3. The nozzle forming member according to claim 1, wherein the inside of the nozzle hole has a large diameter on an ink liquid chamber side,
A nozzle forming member having a nozzle opening having a predetermined diameter on an ink ejection surface side. 4. The nozzle forming member according to claim 1, wherein a nozzle opening having a predetermined diameter is formed by press working on the ink ejection surface side of the nozzle hole. 5. The nozzle forming member according to claim 1, wherein a surface property of the ink jetting surface is Rmax.
= Nozzle forming member characterized by having a roughness of 0.01 to 1 µm. 6. A method for manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, wherein the nozzle hole is formed by performing anisotropic etching on a substrate using both chemical etching and an electric field. A method for manufacturing a nozzle forming member. 7. A plurality of nozzle holes for discharging ink droplets,
6. An ink jet head comprising: an ink liquid chamber in which each nozzle hole communicates; and an energy generating means for pressurizing the ink in the ink liquid chamber, wherein the nozzle forming member forming the nozzle hole is any one of claims 1 to 5. An ink jet head characterized in that it is a nozzle forming member.