JPH10337875A - Nozzle forming member, manufacture thereof and ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nozzle forming member having a high resistance to ink, enabling sure attainment of high component precision and being excellent in mass-production properties and cost reduction by forming a nozzle hole in an SUS base by etching. SOLUTION: A nozzle plate 33 is prepared by forming a nozzle hole 38 in an SUS base 61 such as SUS 304 by etching. As for the internal shape of the nozzle hole 38, the ink liquid chamber side thereof is shaped like a horn of a large diameter, while a nozzle opening 38a of a prescribed diameter is formed by a heterogeneous metal layer 62 laminated on the ink jet face side of the SUS base 61. Moreover, a surface treated film 47 having water repellency is formed on the surface side of the heterogeneous metal layer 62. The SUS base 61 has durability in regard to ionic ink and, by enhancing the anisotropy by an etching method, it is made possible to secure also component precision and to attain mass-production properties and cost reduction. By forming the internal shape of the nozzle hole 38 like the horn, besides, it is made possible to ensure the volume of an ink droplet and to improve a discharge velocity of the ink droplet.

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 using an electroforming method.

[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, it is possible to meet such demands for finer and higher precision of the discharge port, but a nozzle forming member made of a resin material is not used. Damage due to contact with the recording paper and cleaning of the nozzle surface is liable to occur. Especially, 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 process and an electroforming method, the photolithography process is composed of a number of individual processes as is well known, and the overall process 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, since a plating film is formed after patterning a resist pattern on the electroformed support substrate, dirt in a photolithography process, for example, a resist residue, a thermal oxide film on the exposed surface of the substrate due to heat treatment during the process, etc. 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.

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.

[0009]

In order to solve the above-mentioned problems, a nozzle forming member according to claim 1 has a structure in which a nozzle hole is formed in a SUS substrate by etching.

The nozzle forming member according to a second aspect of the present invention is the nozzle forming member according to the first aspect, wherein the inside of the nozzle hole is formed in a horn shape having a large diameter on the ink liquid chamber side, and a nozzle opening having a predetermined diameter is formed on the ink ejection surface side. .

According to a third aspect of the present invention, in the nozzle forming member according to the second aspect, a dissimilar metal is laminated on the ink ejection surface side of the SUS substrate, and the dissimilar metal portion forms the nozzle opening having the predetermined diameter. Configuration.

According to a fourth aspect of the present invention, in the nozzle forming member of the second aspect, any one of an inorganic oxide, a metal oxide, and a nitrogen compound is laminated on the ink ejection surface side of the SUS substrate. The nozzle opening having the predetermined diameter was formed of an inorganic oxide, a metal oxide, or a nitrogen compound.

According to a fifth aspect of the present invention, in the nozzle forming member according to the second aspect, an organic compound is laminated on the ink ejection surface side of the SUS substrate, and the laminated organic compound forms the nozzle opening having the predetermined diameter. Configuration.

According to a sixth aspect of the present invention, in the nozzle forming member according to any one of the first to fifth aspects, the nozzle opening having the predetermined diameter is formed by punching with a press pin.

According to a seventh aspect of the present invention, in the nozzle forming member according to any one of the first to sixth aspects, a water-repellent surface treatment film is formed on the ink jetting surface side.

According to an eighth aspect of the present invention, in the nozzle forming member according to the seventh aspect, an oxide or metal fine particle is mixed in the surface treatment film.

The nozzle forming member according to claim 9 is the nozzle forming member according to any one of claims 1 to 8, wherein
The surface of the US substrate on the ink liquid chamber side is Rmax = 0.3 to 5 μm
m was formed on the rough surface.

According to a tenth aspect of the present invention, in the method of manufacturing a nozzle forming member, after forming the inside of the nozzle hole on the SUS substrate by etching from the ink liquid chamber side, a nozzle opening having a predetermined diameter is formed by etching from the ink jetting surface side. Configuration.

According to a eleventh aspect of the present invention, in the method for manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, a dissimilar metal layer having an opening having a predetermined diameter on the ink ejection surface side of the SUS substrate. After forming any of an inorganic oxide layer, a metal oxide layer, a nitride compound layer, and an organic compound layer, the inside of the nozzle hole is formed by etching from the ink liquid chamber side, and then etching is performed from the ink ejection surface side. And through the opening and the inside.

According to a twelfth aspect of the present invention, in the method of manufacturing a nozzle forming member, after the inside of the nozzle hole is formed on the SUS substrate by etching from the ink liquid chamber side, a hole is formed by a press pin from the ink ejecting surface side. It was configured to form a nozzle opening having a diameter.

According to a thirteenth aspect of the present invention, in the method of manufacturing a nozzle forming member, after forming the inside of the nozzle hole on the SUS substrate by etching from the ink liquid chamber side, the hole having a diameter smaller than a predetermined diameter is etched by the ink jetting surface side. Then, the small-diameter hole is punched with a press pin to form a nozzle opening having a predetermined diameter.

According to a fourteenth 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 of the nozzle holes; and an energy generating means for pressurizing the ink in the ink liquid chamber. In the head, the nozzle forming member that forms the nozzle hole is the nozzle forming member according to any one of claims 1 to 9.

[0023]

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 the piezoelectric elements 17 (to be referred to as “driving units”) to which a driving pulse for applying ink to form droplets and fly is provided, and the driving units 17. 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 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 (d33).
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 a 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 via 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 formed 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 flying 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.

Then, the substrate 11 is supported and held on a spacer member (head holder) 50 as a head support member, and the head driving I
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.

The 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 ink droplet ejection, 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, details of the nozzle plate 33 will be described with reference to FIG. FIG. 4 is an enlarged sectional view of a main part of one nozzle hole portion of the nozzle plate 33. The nozzle plate 33 has a nozzle hole 38 formed by etching a SUS substrate 61 such as SUS304. This SUS
The internal shape of the nozzle hole 38 formed in the substrate 61 is a horn shape having a large diameter on the ink liquid chamber side, and a nozzle opening 38 a having a predetermined diameter is formed by a dissimilar metal layer 62 laminated on the ink ejection surface side of the SUS substrate 61. I have. Further, a surface treatment film 47 having water repellency is formed on the surface side of the dissimilar metal 62.

Here, as the SUS substrate 61, the ink jetting surface side surface 61a has a BA (bright annealing / reducing atmosphere rolling) finish, so that there is no abnormal reflection in the photolithography process for etching as described later. A highly accurate resist pattern can be formed. Also,
The surface 61b of the ink liquid chamber side has a surface roughness of about 0.5 to 3 μm by 2B (rolling in the air) finish, and the anchor effect at the time of joining the liquid chamber partition member 32 with the photosensitive resin layer 46 is improved. Obtainable. This ink liquid chamber side surface 61b
Can be roughened to a surface roughness of 0.5 to 3 μm by etching.

As described above, by forming a nozzle hole in a SUS substrate as a nozzle forming member by etching, the SUS substrate has durability against ionic ink, and component precision can be secured by increasing anisotropy by an etching method. Thus, mass productivity and cost reduction can be achieved. Also,
By making the inside shape of the nozzle hole into a horn shape, the pressure wave from the energy generating means can be concentrated toward the nozzle opening, the volume of the ink droplet can be secured, and the ink droplet discharge speed can be improved.

The dissimilar metals forming the dissimilar metal layer 62 include Au, Pt, Ni, W, Mo, Ru, Ni-Cr,
Ti or the like can be used. By forming the nozzle openings 38a of the nozzle holes 38 of the dissimilar metal layer 62, a highly accurate nozzle diameter on the ink ejection surface can be obtained. The thickness of the dissimilar metal layer 62 is preferably about 0.1 to 30 μm. If the thickness is less than 0.1 μm, it becomes difficult to secure a highly accurate nozzle opening diameter. If the thickness exceeds 30 μm, distortion, deformation, and the like are caused by internal stress (during film formation and after annealing for improving adhesion) due to dissimilar materials. Further, a minute deformation of the inner hole diameter (hole diameter) may occur due to the enlargement of the crystal.

Instead of the dissimilar metal layer 62, an inorganic oxide, a metal oxide,
One of the nitrogen compounds is laminated to form an inorganic oxide layer, a metal oxide layer, or a nitrogen compound layer, and the nozzle hole 3 is formed of the inorganic oxide layer, the metal oxide layer, or the nitrogen compound layer.
Eight nozzle openings 38a having a predetermined diameter can also be formed. Here, SiO ₂ , MgO or the like can be used as the inorganic oxide, and Al ₂ O ₅ ,
TiO ₂ , Ta ₂ O ₅ , RuO _{3 and the} like can be used, and as the nitrogen compound, Si ₃ N ₄ , SiON, BN, SiN and the like can be used. The thickness of the inorganic oxide layer, metal oxide layer, or nitrogen compound layer is preferably 0.1 to 5 μm. If the thickness is less than 0.1 μm, it is difficult to secure a highly accurate nozzle opening diameter, and if it exceeds 5 μm. When the internal stress deformation, strain and oxide crystal grains increase, minute deformation may be observed on the inner wall of the nozzle.

As described above, the inorganic oxide layer, the metal oxide layer,
Alternatively, by forming a nozzle opening 38a having a predetermined diameter of the nozzle hole 38 with a nitrogen compound layer, a water-repellent surface treatment film 47 is formed without forming a local battery, having high abrasion resistance, and a fine porous surface. The agent can be easily filled and adhered, and the adhesion and durability can be improved.

In place of the dissimilar metal layer 62, an organic compound may be laminated on the ink jetting surface of the SUS substrate 61, and a nozzle opening 38a having a predetermined diameter of the nozzle hole 38 may be formed by the organic compound layer. it can. As the organic compound, an organic resin such as polyimide, parylene, or a liquid crystal polymer resin can be used. The thickness of the organic compound is preferably from 0.3 to 20 μm. If the thickness is less than 0.3 μm, it becomes difficult to secure a highly accurate nozzle opening diameter.
If m is exceeded, the deformation of the nozzle may be increased due to the influence of the thermosetting shrinkage of the organic resin, and the decrease in Young's modulus cannot be ignored.

By forming the nozzle opening 38a having a predetermined diameter of the nozzle hole 38 with the organic compound layer in this manner, a highly accurate nozzle diameter on the ink jetting surface can be obtained, and deformation of the nozzle plate due to film stress can be prevented. Can be suppressed.

The surface treatment film 47 is made of PTFE, FEP, P
It is formed of a fluororesin such as FA. Surface treatment film 47
By forming, the ink droplet shape and flying characteristics are stabilized, and high quality image quality can be obtained. This surface treatment film 47
The wiping resistance (abrasion resistance) can be improved by mixing fine particles of fine particles of oxide or metal. Fine particles include calcium fluoride, CaF ₂ , SiO ₂ , S
Oxide fine particles such as i ₃ N ₄ , MgO, Al ₂ O 3, Ni, Mn,
Fine metal particles such as W and Mo can be used, and the fine particle diameter is about 0.3 to 1.5 μm.
It is preferable to secure the adhesion to one or different metal layers 62 (including other inorganic oxide layers, metal oxide layers, etc.) and to improve the wear resistance.

Next, a first example of a method for manufacturing a nozzle forming member using the above SUS substrate will be described with reference to FIG. FIG. 3 is an enlarged explanatory view of a main part for explaining one nozzle hole portion of the nozzle forming member. First, a resist is applied to the ink ejection surface side and the ink liquid chamber side of the SUS substrate 61 as shown in FIG. A resist pattern 71 having an opening 71a corresponding to a predetermined nozzle diameter (nozzle opening diameter, for example, 10 to 50 μm) is provided on the ink ejection surface side of the SUS substrate 61, and a required nozzle diameter (for example, 30 to 200 μm) is provided on the ink liquid chamber side. A resist pattern 72 having an opening 72a corresponding to ()) is formed. Note that positional accuracy can be ensured by simultaneously exposing the resist on both sides.

Thereafter, as shown in FIG. 7B, the SUS substrate 61 is etched by spray etching from the side of the ink liquid chamber where the allowable value of the dimensional accuracy is large.
To form For etching the SUS substrate 61, usually,
The oxidation-reduction reaction by the addition of hydrochloric acid of iron chloride is used. However, since this is an isotropic etching, the dipping method (D
According to the ipping method or shower etching, it is difficult to obtain a highly accurate pattern shape due to the progress of the side edge.
Therefore, by performing spray etching to increase the anisotropy, it is possible to obtain a high-precision nozzle hole with little side edge.

This spray etching is performed by spraying a FeCl ₃ -based etchant from the central nozzle hole 74a and spraying N ₂ or air from the peripheral nozzle hole 74b using a spray etching nozzle 74 as shown in FIG. be able to. The ion replacement ratio of the reactive species between the etchant and the SUS substrate is increased by the injection force of N2 or air, so that etching can be performed with a quick reaction and a small side etch amount.

After the SUS substrate 61 is etched from the ink liquid chamber side by a predetermined thickness or more (preferably 70% or more of the total thickness) from the ink liquid chamber side, ink is ejected as shown in FIG. Etching is performed from the surface side to penetrate the etching hole 73. In this case, etching from the ink liquid chamber side can be performed simultaneously with etching from the ink ejection surface side.

Next, by removing the resist patterns 71 and 72 on the SUS substrate 61 as shown in FIG. 4D, the SUS substrate 61 having the nozzle holes 38 formed in the etching holes 73 can be obtained.

As described above, by forming the nozzle holes by etching using the SUS substrate, a nozzle forming member having high-precision nozzle holes can be manufactured at low cost. In this case, since the large-diameter ink liquid chamber side of the nozzle hole has a large allowable value of the dimensional accuracy, etching is started from the ink liquid chamber side of the SUS substrate to etch a predetermined thickness (preferably 70% or more). By forming a nozzle opening by performing etching from the ink jetting surface side together with etching from the ink liquid chamber side or independently, a highly accurate nozzle opening (accuracy of ± 2% or less is required). Can be formed.

Next, a second example of a method for manufacturing a nozzle plate using a SUS substrate will be described with reference to FIGS. In addition, both figures are main part enlarged explanatory views for explaining one nozzle hole portion of the nozzle plate. First, as shown in FIG. 7A, a resist is applied to the ink ejection surface side and the ink liquid chamber side of the SUS substrate 61, and the resist is subjected to simultaneous double-sided exposure using a predetermined exposure mask, and then developed.
A high-precision resist pattern 75 having the same diameter as a predetermined nozzle diameter (nozzle opening diameter) is formed on the ink jetting surface side of the SUS substrate 61, and the same as the first example corresponding to the required nozzle diameter on the ink liquid chamber side Then, a resist pattern 72 having an opening 72a is formed.

Thereafter, Au, Pt, Ni, W, Mo, and R are applied to the ink jetting surface of the SUS substrate 61 as shown in FIG.
A metal material such as u, Ni-Cr, or Ti is sputter-deposited by a lift-off method to form a heterogeneous metal layer 62 having a thickness of 0.1 to 30 μm. Then, the resist pattern 75 corresponding to the nozzle opening is removed, and the nozzle opening 38a is formed by the dissimilar metal layer 62.

It is also possible to form a nozzle opening 38a having a predetermined diameter by depositing a dissimilar metal material on the front surface of the ink ejection surface of the SUS substrate 61 and then etching the dissimilar metal layer with a dedicated etchant using a photolithography process. .

Next, as in the first example, the SUS substrate 61 is etched by spray etching from the ink liquid chamber side where the allowable value of the dimensional accuracy is large, as shown in FIG. After etching 70% or more of the thickness of the SUS substrate 61, etching is performed from the ink ejection surface side using the dissimilar metal layer 62 as a mask, so that the etching hole 73 penetrates the nozzle opening 38a.

Then, by removing the resist pattern 75 on the SUS substrate 61 as shown in FIG. 9E, the SUS substrate 61 having the nozzle holes 38 in which the nozzle openings 38a are formed in the dissimilar metal layer 62 is obtained. be able to.

Next, as shown in FIG.
A negative photosensitive resin film (dry film resist) 76 is laminated from the ink liquid chamber surface of the SUS substrate 61 on which the substrate 8 is formed, and heated and pressed to fill the nozzle holes 38 and protrude toward the ink ejection surface side. Extruded part 7
6a is formed. The amount of the protruding portion 76a protruding from the ink ejection surface is set to be larger than the thickness of the water-repellent treatment film 47 to be formed. Here, the water-repellent surface treatment film 47 is used.
Is set to 1 to 10 μm, so that the thickness exceeds 10 μm.

Therefore, the protruding portion 76a is heated again to soften it, so as to have a shape slightly larger than the nozzle opening diameter as shown in FIG.
After the nozzle opening 38a is securely covered with the edge portion, the nozzle opening 38a is exposed to ultraviolet (UV) light from the ink liquid chamber side using the SUS substrate 61 as a mask, and is cured. As shown in FIG. The masking member 77 has a convex portion 77a protruding from the inside of the hole 38 toward the ink ejection surface.

In this state, the perfluorosilane coupling agent and the P
Fine particles of TFE (polytetrafluoroethylene) and F
To a mixture of EP (tetrafluoroethylene-hexafluoropropylene copolymer) and PFA (tetrafluoroethylene-perfluoroalkylvinyl copolymer) with fine particles of a thermoplastic polyfluoro compound, calcium fluoride,
Oxide fine particles such as CaF ₂ , SiO ₂ , Si ₃ N ₄ , MgO, and Al ₂ O ₃ or metal fine particles such as Ni, Mn, W, and Mo (fine particle diameter: about 0.3 to 1.5 μm) are added. The resulting mixture was applied as a thin film having a thickness of 1 to 10 μm,
By performing a heat treatment at 350 ° C. for one hour, a surface treatment film 47 is formed as shown in FIG. 4D, and the masking member 77 is removed to obtain the nozzle plate 33.

Here, the perfluorosilane coupling agent is added to the surface treatment material in order to increase the adhesion strength, and the addition amount is preferably 1 to 20% by weight. As the perfluorosilane coupling agent, specifically, AY
43-158E (trade name, manufactured by Toray), KBM7103,
KBM-7803 (all trade names, manufactured by Shin-Etsu Silicone), TSL8233 (trade name, manufactured by Toshiba Silicone) and the like can be mentioned.

Specific examples of PTFE, FEP, and PFA include fluororesin products such as polyflon, neophoron, and rubron (all trade names, manufactured by Daikin Industries, Ltd.). From these fluororesin product groups, 99-80% by weight of a fine particle component is added and mixed, and the ink jetting surface is coated with 1-5 μm by a thin film forming method, and then dried at 80 ° C. for 30 minutes in a pre-bake, and dried.
The surface treatment film 47 is obtained by aging at 0 to 300 ° C. for 1 hour.

After the surface treatment film 47 is formed as described above, the side of the ink liquid chamber of the SUS substrate 61 of the nozzle plate 33 is subjected to an acid treatment (etching treatment) using an iron chloride solution, a mineral acid solution or the like. By applying, Rmax 0.3-5μ
The surface is roughened to about m to improve the bonding strength with the liquid chamber partition member.

In this second example, instead of the dissimilar metal layer, an inorganic oxide layer such as SiO ₂ or MgO, or Al ₂ O ₅ , TiO ₂ , Ta ₂ O ₅ , RuO _3, etc. A metal oxide layer, a nitride compound layer such as Si ₃ N ₄ , SiON, BN, or SiN, or an organic compound layer such as polyimide or parylene can also be formed.

Here, as the polyimide used for forming the organic compound layer, there may be mentioned, for example, Photonis (trade name, manufactured by Toray) and Lithocoat PI-400 (trade name, manufactured by Ube Industries) having a photosensitive group. These can secure a highly accurate nozzle opening diameter by a direct photolithography process. In addition, a polyimide varnish coat film can be formed, but the process becomes complicated.
Further, parylene is deposited and formed at low pressure under heating, but a predetermined nozzle opening diameter can be obtained by a lift-off method.

Next, a third example of a method for manufacturing a nozzle forming member using a SUS substrate will be described with reference to FIG.
In the third example, a horn-shaped etching hole 73 was formed from the ink liquid chamber side of the SUS substrate 61 as shown in FIG. 9A in the same manner as in FIGS. 5A to 5D described above. Thereafter, as shown in FIG. 3 (b), a press pin having a predetermined nozzle opening diameter is used to form a press hole in a thin portion remaining after etching to form a nozzle opening.

Next, a fourth example of a method for manufacturing a nozzle forming member using a SUS substrate will be described with reference to FIG. In the fourth example, a horn-shaped etching hole 73 is formed from the ink liquid chamber side of the SUS substrate 61 as shown in FIG. 10A in the same manner as in FIGS. 5A to 5D described above. Further, as shown in FIG. 3B, the etching hole 73a having a diameter slightly smaller than a predetermined nozzle opening diameter from the ink ejection side.
Then, as shown in FIG. 3C, a press hole is formed in the etching hole 73a by using a press pin having a predetermined nozzle opening diameter to form a nozzle opening.

When a nozzle opening is formed by performing a punching process with a press pin as described above, by forming an etching hole having a slightly smaller diameter in advance, the internal stress at the time of pressing is reduced and the internal deformation is extremely reduced. Can be reduced.

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.

[0071]

As described above, according to the nozzle forming member of the first aspect, since the nozzle hole is formed by etching in the SUS substrate, durability against ionic ink is obtained, and the etching method is used. By increasing the anisotropy, component accuracy can be secured, and mass productivity and cost reduction can be achieved.

According to the nozzle forming member of the second aspect, in the nozzle forming member of the first aspect, the inside of the nozzle hole is formed in a horn shape having a large diameter on the ink liquid chamber side and a nozzle having a predetermined diameter on the ink jetting surface side. Since the opening is formed, the pressure wave can be concentrated, the ink droplet ejection volume can be secured, and the ink droplet ejection speed can be improved.

According to the nozzle forming member of the third aspect, in the nozzle forming member of the second aspect, a dissimilar metal is laminated on the ink ejection surface side of the SUS substrate, and a nozzle opening having a predetermined diameter is formed in the dissimilar metal portion. With this configuration, high nozzle diameter accuracy can be ensured.

According to the nozzle forming member of the fourth aspect, in the nozzle forming member of the second aspect, any one of an inorganic oxide, a metal oxide, and a nitrogen compound is laminated on the ink jetting surface side of the SUS substrate. Inorganic oxides, metal oxides,
Since the nozzle opening with a predetermined diameter is formed with a nitrogen compound, high nozzle diameter accuracy can be secured, a local battery is not formed, abrasion resistance is high, adhesion when forming a surface treatment film,
Durability can be improved.

According to the nozzle forming member of the fifth aspect, in the nozzle forming member of the second aspect, an organic compound is laminated on the ink ejection surface side of the SUS substrate, and a nozzle opening having a predetermined diameter is formed by the laminated organic compound. Configuration
High nozzle diameter accuracy can be secured, and deformation due to film stress can be reduced.

According to the nozzle forming member of the sixth aspect, in the nozzle forming member of any one of the first to fifth aspects,
Since a nozzle opening having a predetermined diameter is formed by punching with a press pin, pin wear is small, mass productivity is improved, and nozzle diameter accuracy can be secured.

According to the nozzle forming member of the seventh aspect, in the nozzle forming member of any one of the first to sixth aspects,
Since the surface treatment film having water repellency is formed on the ink ejection surface side, good ink droplet ejection characteristics can be obtained.

According to the nozzle forming member of claim 8, in the nozzle forming member of claim 7, the surface treatment film has a structure in which fine particles of oxide or metal are mixed.
The wear resistance of the surface treatment film can be improved.

According to the nozzle forming member of the ninth aspect, in the nozzle forming member of the first aspect,
The surface of the SUS substrate on the ink liquid chamber side is Rmax = 0.3 to 5
Since the structure is formed on the rough surface of μm, the bonding strength with the member forming the ink liquid chamber can be improved.

According to the manufacturing method of the nozzle forming member of the tenth aspect, after forming the inside of the nozzle hole in the SUS substrate by etching from the ink liquid chamber side, the nozzle opening of a predetermined diameter is formed by etching from the ink jetting surface side. Since the nozzle forming member is formed, a nozzle forming member having high ink diameter accuracy can be manufactured with good mass productivity and at low cost.

According to the method of manufacturing a nozzle forming member according to the eleventh aspect, a dissimilar metal layer, an inorganic oxide layer, a metal oxide layer, a nitride compound layer, and an organic layer having an opening of a predetermined diameter on the ink ejection surface side of the SUS substrate. After forming any of the compound layers, the inside of the nozzle hole is formed by etching from the ink liquid chamber side, and then the nozzle is formed by etching from the ink jetting surface side to pass through the opening and the inside. With the configuration, a highly accurate nozzle diameter can be secured.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a nozzle forming member, wherein after forming the inside of a nozzle hole on a SUS substrate by etching from an ink liquid chamber side, a predetermined hole is formed by a press pin from an ink jetting surface side. Since the nozzle opening having a diameter is formed, a nozzle forming member having a small diameter, a small consumption of pins, good mass productivity, and a highly accurate nozzle diameter can be obtained.

According to the manufacturing method of the nozzle forming member of the thirteenth aspect, after the inside of the nozzle hole is formed on the SUS substrate by etching from the ink liquid chamber side, the diameter is smaller than the predetermined diameter by etching from the ink jetting surface side. A hole is formed, and a hole is formed with a press pin in this small-diameter hole to form a nozzle opening having a predetermined diameter.Therefore, pin consumption is small, deformation due to internal stress is small, and mass productivity is further improved. A nozzle forming member having a highly accurate nozzle diameter can be obtained. .

According to the fourteenth 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. Since the nozzle forming member for forming the nozzle hole is the nozzle forming member according to any one of claims 1 to 9, 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 an enlarged sectional view of a main part of a nozzle plate of the head.

FIG. 5 is a schematic cross-sectional view illustrating a first example of a method for manufacturing a nozzle plate of the head.

FIG. 6 is a schematic sectional view illustrating a spray etching gun used in the manufacturing method.

FIG. 7 is a schematic cross-sectional view illustrating a second example of the method of manufacturing the nozzle plate of the head.

FIG. 8 is a schematic cross-sectional view continued from the first example of the manufacturing method.

FIG. 9 is a schematic cross-sectional view illustrating a third example of the method for manufacturing the nozzle plate of the head.

FIG. 10 shows a fourth method of manufacturing the nozzle plate of the head.
Schematic cross-sectional view explaining an example

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive unit, 2 ... Liquid chamber unit, 12 ... Piezoelectric element, 33 ... Nozzle plate, 38 ... Nozzle hole, 38a ...
Nozzle opening, 47: Surface treatment film, 61: SUS substrate, 6
2: Different metal layers.

Claims (14)

[Claims] 1. A nozzle forming member having a nozzle hole for discharging an ink droplet, wherein the nozzle hole is formed in a SUS substrate by etching. 2. The nozzle forming member according to claim 1, wherein the inside of the nozzle hole has a large diameter horn shape on the ink liquid chamber side, and has a nozzle opening of a predetermined diameter on the ink ejection surface side. A nozzle forming member characterized by the above-mentioned. 3. The nozzle forming member according to claim 2, wherein a dissimilar metal is laminated on the ink ejection surface side of the SUS substrate, and the dissimilar metal portion forms the nozzle opening having the predetermined diameter. Nozzle forming member. 4. The nozzle forming member according to claim 2, wherein any one of an inorganic oxide, a metal oxide, and a nitrogen compound is stacked on the ink ejection surface side of the SUS substrate, and the stacked inorganic oxide and metal oxide are stacked. A nozzle forming member, wherein the nozzle opening having the predetermined diameter is formed of a substance or a nitrogen compound. 5. The nozzle forming member according to claim 2, wherein an organic compound is laminated on the ink ejection surface side of the SUS substrate, and the laminated organic compound forms the nozzle opening having the predetermined diameter. Nozzle forming member. 6. The nozzle forming member according to claim 1, wherein the nozzle opening having a predetermined diameter is formed by punching with a press pin. . 7. The nozzle forming member according to claim 1, wherein a water-repellent surface treatment film is formed on the ink jetting surface side. 8. The nozzle forming member according to claim 7, wherein fine particles of an oxide or a metal are mixed in the surface treatment film. 9. The nozzle forming member according to claim 1, wherein the surface of the SUS substrate on the ink liquid chamber side is formed to have a rough surface of Rmax = 0.3 to 5 μm. Nozzle forming member. 10. A method of manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, wherein the inside of the nozzle hole is formed on a SUS substrate by etching from an ink liquid chamber side, and then etched from an ink ejection surface side. A method for manufacturing a nozzle forming member, wherein a nozzle opening having a predetermined diameter is formed. 11. A method for manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, comprising: a dissimilar metal layer, an inorganic oxide layer, a metal oxide layer having an opening having a predetermined diameter on the ink ejection surface side of the SUS substrate; After forming any one of the nitride compound layer and the organic compound layer, after forming the inside of the nozzle hole by etching from the ink liquid chamber side, etching is performed from the ink ejection surface side to pass through the opening and the inside. A method for manufacturing a nozzle forming member, comprising forming a nozzle hole. 12. A method of manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, wherein after forming the inside of the nozzle hole on a SUS substrate by etching from an ink liquid chamber side, a press pin is formed from an ink ejection surface side. And forming a nozzle opening having a predetermined diameter by drilling. 13. A method of manufacturing a nozzle forming member having a nozzle hole for discharging an ink droplet, wherein the inside of the nozzle hole is formed on a SUS substrate by etching from an ink liquid chamber side, and then etched from an ink jetting surface side. A method of manufacturing a nozzle forming member, comprising: forming a hole having a diameter smaller than a predetermined diameter; and forming a hole with a predetermined diameter by punching the hole having a small diameter with a press pin. 14. 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 ink in the ink liquid chamber. 10. An ink jet head, wherein a nozzle forming member for forming the nozzle is the nozzle forming member according to claim 1.