JP2001063068A - Ink-jet head and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a highly accurate ink supply path at a low cost by providing an ink-jet head with a nozzle hole and a groove serving as the ink supply path formed as the same member. SOLUTION: A nozzle plate 3 is bonded on the upper surface of a liquid room forming plate 1. In the nozzle plate 3, a nozzle hole 11 including a nozzle inlet part 11a communicating with a pressure room 6, and a fine groove 14 comprising an ink supply path 13 as a communication groove serving also as a fluid resistor part, communicating with the pressure room 6 and a common ink room 8, are formed. The nozzle hole 11 and the ink supply path 13 are formed as the same member. Thereby, since the ink supply path 13 serves as a fluid resistor so that the ink inflow to the common ink room 8 side can be restrained, ink droplet ejection can be carried out efficiently, and ink droplets can be jetted by all channels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and a method of manufacturing the same, and more particularly to an ink jet head having an ink supply path for supplying ink to a pressure chamber and a method of manufacturing the same.

[0002]

2. Description of the Related Art An ink jet head used in an image recording apparatus such as a printer, a facsimile or a copying apparatus or an ink jet recording apparatus used as an image forming apparatus includes a nozzle for ejecting ink droplets and a pressure chamber (a pressure chamber) communicating with the nozzle. A pressure chamber, a pressure chamber, a discharge chamber, a liquid chamber, an ink flow path, etc.) and an energy generating means for generating energy for pressurizing the ink in the pressure chamber. By doing so, the ink in the pressure chamber is pressurized to eject ink droplets from the nozzle holes, and an ink-on-demand type that ejects ink droplets only when recording is necessary is the mainstream.

Conventionally, as an energy generating means for generating energy for pressurizing ink in a pressure chamber, a diaphragm forming a wall surface of the pressure chamber is deformed by using a piezoelectric element to change the volume of the pressure chamber to eject ink droplets. (See JP-A-2-51734), or an ink droplet is ejected with a pressure generated by heating ink in a pressure chamber using a heating resistor to generate bubbles. Japanese Patent Application Laid-Open No. 61-59911 discloses a method in which a diaphragm forming a wall surface of a pressure chamber is deformed by electrostatic force so as to change the volume of the pressure chamber to eject ink droplets (Japanese Patent Application Laid-Open No. Hei 6-1994). -71882)
Etc. are known.

In these various ink jet heads, new ink is supplied to a pressure chamber from a common ink chamber (also referred to as a common ink flow path or a common liquid chamber) in accordance with the amount of ink consumed in the pressure chamber. An ink supply path for performing the operation. In this case, in order to efficiently use the pressure change in the pressure chamber for ejecting ink droplets, the ink supply path is formed as a fine hole or groove, and functions as a fluid resistance part that performs an ink backflow reducing action. Head downsizing,
With the increase in the number of nozzles, miniaturization of pressure chambers and ink supply paths is required.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. Hei 6-31914, for example, the S
An i-wafer and an Si wafer or borosilicate glass substrate having an arbitrary plane orientation are bonded together to form an (110) -oriented S wafer.
It is known that a pressure chamber is formed on an i-wafer, and a groove for forming a nozzle and an ink supply path is formed when a Si wafer having an arbitrary plane orientation and a Si wafer having a crystal plane orientation (110) are bonded to a borosilicate glass substrate. Have been.

Further, as disclosed in JP-A-6-305142, a first substrate on which an energy generator for discharging ink from a nozzle opening is disposed,
A second substrate disposed to face the first substrate, and an ink that forms an ink flow path together with the first substrate and the second substrate positioned between the first substrate and the second substrate. A device provided with a flow path forming member is also known.

[0007]

However, a groove for forming a nozzle and an ink supply path when bonded to a Si wafer having an arbitrary plane orientation or a Si wafer having a crystal plane orientation of (110) is formed on the above-mentioned Si wafer or borosilicate glass substrate. The material to be formed is limited in material and is limited to a groove-shaped nozzle, and has a problem that a water-repellent treatment or the like cannot be performed.

[0008] Further, since the ink supply path is formed by the substrate for forming the pressure chamber, the number of laminated components increases and the configuration becomes complicated. Further, since the ink supply path also needs to be formed with high precision because it also serves as a fluid resistance, if the ink supply path is formed in a member forming the pressure chamber, the ink supply path is formed with high precision including the pressure chamber portion. Need to increase costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an ink jet head which can be manufactured at a low cost with a high-precision ink supply path and has a simple structure, and a method of manufacturing the same.

[0010]

In order to solve the above-mentioned problems, an ink jet head according to the present invention has a structure in which a nozzle hole and a groove forming an ink supply path are formed in the same member.

Further, the ink jet head according to the present invention has a configuration in which a plurality of ink supply paths are formed for one pressure chamber.

Further, the ink jet head according to the present invention has a structure in which a groove not communicating with the pressure chamber and the common ink chamber is formed on the side of the ink supply path.

Furthermore, in the ink jet head according to the present invention, a groove forming an ink supply path is formed in a member forming a nozzle, and a plurality of ink supply paths are formed for one pressure chamber. Alternatively, a groove that does not communicate with the pressure chamber and the common ink chamber is formed on the side of the ink supply path.

Here, when forming a groove for forming an ink supply path in a member for forming a nozzle, it is preferable that the width of the groove for forming the ink supply path is twice or less the depth of the nozzle.

The method of manufacturing an ink jet head according to the present invention is a method of manufacturing an ink jet head in which a groove for forming an ink supply path is formed in a member for forming a nozzle. To form
After exposing the first photosensitive organic film through a first mask, a second photosensitive organic film is formed on the first photosensitive organic film, and the second photosensitive organic film is After exposing through the second mask, the first and second photosensitive organic films are developed to form a laminated organic film pattern corresponding to a portion where a nozzle and a groove are to be formed. A metal film is formed thereon by electroforming. In this case, it is preferable to form a water-repellent layer on the surface after forming the metal film.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory sectional view of a piezo type inkjet head according to a first embodiment of the present invention, and FIG. 2 is an explanatory plan view showing the nozzle plate of FIG. 1 in a transparent state.

This ink jet head includes a liquid chamber forming plate 1, a vibration plate 2, a nozzle plate 3, and a laminated piezoelectric element 4. The liquid chamber forming plate 1 is provided with a through hole 7 forming a pressure chamber 6 and a through hole 9 forming a common ink chamber 8. A vibration plate 2 forming a wall surface of a pressure chamber 6 is provided on a lower surface of the liquid chamber forming plate 1, and a piezoelectric element 4 is provided on an outer surface of the vibration plate 2 to constitute an actuator unit.

A nozzle plate 3 is joined to the upper surface of the liquid chamber forming plate 1. The nozzle plate 3 has a nozzle hole 11 including a nozzle inlet 11 a communicating with the pressure chamber 6, and a common ink chamber. 8 and a narrow groove 14 which forms an ink supply path 13 which is a communication groove also serving as a fluid resistance portion communicating with the ink supply path 8.

In the ink jet head configured as described above, when a driving voltage is applied to the piezoelectric element 4, the piezoelectric element 4 is displaced in the stacking direction, and the diaphragm 2 is deformed and displaced toward the pressure chamber 6, and the pressure is reduced. The internal volume of the chamber 6 decreases,
The pressure in the pressure chamber 6 increases, and ink droplets are ejected from the nozzle holes 11. At this time, the ink in the pressure chamber 6 attempts to flow into the common ink chamber 8 through the ink supply path 13, but the ink supply path 13 becomes a fluid resistance, so that the ink flow into the common ink chamber 8 is suppressed. Therefore, efficient ink droplet ejection can be performed.

Then, with the end of the ink droplet ejection, the ink pressure in the pressure chamber 6 is reduced, and a negative pressure is generated in the pressure chamber 6 due to the inertia of the ink flow and the discharge process of the driving voltage, and the ink filling process is started. Then, the pressure chamber 13 is filled with ink from the common ink chamber 6 through the ink supply path 13. Then, the vibration of the ink meniscus surface near the outlet of the nozzle hole 11 is attenuated, and if the state returns to a steady state to some extent, the operation shifts to the next ink droplet ejection operation.

Here, in this ink-jet head, as described above, the narrow groove 14 for forming the ink supply path 13 is formed in the nozzle plate 3 which is a member for forming the nozzle hole 11, so that any of them is used. The nozzle hole 11 and the ink supply path 13 that require high precision because they greatly affect the ejection characteristics can be formed by the same member, and a low-cost and high-precision ink supply path can be obtained.

That is, if the ink supply path is too small, the fluid resistance increases, so that when the ink droplets are ejected at a high frequency, the replenishment of the pressure chamber with the ink becomes insufficient.
Conversely, if the ink supply path is too large, the fluid resistance decreases, and the amount of ink flowing back to the common ink chamber side increases when the diaphragm is deformed and displaced to reduce the pressure chamber volume. The ink amount of the droplet decreases, and the ejection efficiency decreases. Therefore, the ink supply path is required to have a particularly high accuracy, and if the ink supply path is formed in the member for forming the pressure chamber, sufficient accuracy cannot be obtained. And the cost is increased.

Next, a method of manufacturing the ink jet head according to the present invention will be described with reference to FIG. First, as shown in FIG. 3A, on a conductive substrate 20 which is an electroformed support substrate having at least a good surface conductivity, such as a metal plate of stainless steel or a glass plate having a surface coated with a metal film. Then, a first photosensitive organic film 21 such as a negative resist or a dry film resist is formed. The thickness of the organic film is determined corresponding to the height of the ink supply path 13 to be finally formed.

Next, as shown in FIG. 2B, a nozzle entrance portion of the first photosensitive organic film 21 is passed through a first mask member 23 by using a contact type exposure device or a reduction exposure device. Then, the portions 21a and 21b where the ink supply path narrow grooves are formed are exposed. Here, the pattern shape of the nozzle portion is preferably a pattern that is equal to or slightly larger than the final nozzle. Further, the pattern corresponding to the narrow groove for the ink supply path is selected in consideration of the fluid resistance in the ink supply path, the bubble discharge property, and the like in accordance with the thickness of the first photosensitive organic film 21.

Next, as shown in FIG. 1C, a second photosensitive organic film 22 is formed on the first photosensitive organic film 21. Then, as shown in FIG. 4D, a portion 22a of the second photosensitive organic film 22 where the nozzle is formed is formed through the second mask member 24 using a contact type exposure device or a reduction exposure device. Is exposed. Here, the pattern shape to be exposed has the same shape as the nozzle to be finally formed.

Next, as shown in FIG.
After the second exposure step, the first photosensitive organic film 21 and the second
Are simultaneously developed to form an organic film pattern 25 corresponding to the nozzle and the ink supply path. Thereafter, as shown in FIG. 1F, a metal film 26 such as Ni or Ni--Co alloy is formed on the conductive substrate 20 along the organic film pattern 25 by electroforming.

Then, the formed metal film 26 is peeled from the conductive substrate 20 and the organic film pattern 25 is removed.
As shown in FIG. 1G, a nozzle plate 3 in which a nozzle hole 11 and a narrow groove 14 serving as an ink supply path 13 are integrally formed is obtained.

Another method for obtaining such a shape is as follows.
For example, there is laser processing. By using a resin film as the material of the nozzle plate and processing with excimer laser, highly accurate grooves and holes can be formed and equivalent shapes can be obtained, but it is preferable that the nozzle plate has high rigidity Therefore, in terms of obtaining a metal nozzle plate, it is preferable to produce the nozzle plate by the above-described electroforming method.

Although the case where a negative resist is used is described here, a nozzle plate having a similar shape can be manufactured by using a positive resist by changing a mask member and exposure conditions. can do.

After the electroformed metal is deposited on the conductive substrate 20 as shown in FIG. 3 (f), it is continuously formed by eutectoid plating containing fine particles of fluorine resin such as PTFE. A water-repellent layer can be formed on the surface of the metal film 26 (the surface serving as the nozzle surface of the nozzle plate). Thereby, the ink droplet ejection characteristics are improved.

In the case where the narrow groove 14 serving as the groove-shaped ink supply path 13 shown in FIG. 2 is formed by the above-described electroforming method, if the width of the groove 14 is too large with respect to the electroformed film thickness,
In some cases, a groove having a good shape cannot be formed. That is,
FIG. 4 shows a cross section in the groove short side direction of the ink supply path forming portion. In general, since the organic film pattern 25 is not a good conductor, the metal film 26 is formed by electroforming as shown in FIG. It grows so as to protrude on the film pattern 25.

In this case, since the horizontal protrusion amount a of the metal film 26 is substantially equal to the height height h of the metal film 26, the narrow groove 14 serving as an ink supply path is completely formed as shown in FIG. In order to obtain a shape, when the width of the organic film pattern 25 is w, it is necessary that w <2 × h. Here, since the height h of the metal film 26 in the height direction corresponds to the depth of the nozzle, the width of the ink supply path needs to be twice or less the depth of the nozzle.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, a plurality of ink supply paths 13 (here, two ink supply paths) are provided for one pressure chamber 6.
Provided.

That is, since the ink supply path 13 functions as a fluid resistance section, when the width of the ink supply path 13 becomes narrow, the fluid resistance becomes large and the ink supply during continuous recording becomes insufficient. By providing a plurality of ink supply paths in one pressure chamber, shortage of ink supply can be avoided, and stable ink droplet ejection can be performed. In particular,
When the narrow groove for the ink supply path is formed in the nozzle plate, since the width of the narrow groove for the ink supply path is limited as described above,
By forming a plurality of narrow grooves, the effective groove width can be increased.

In addition, when a structure is provided in which a plurality of ink supply paths are provided, the second photosensitive organic film 2 described above is formed.
2 can be made thinner, so that a wider range of materials can be selected. Further, since the unevenness of the nozzle plate surface can be reduced, the cleaning property of the nozzle surface is improved.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, side grooves 15, 15 not communicating with the pressure chamber 6 and the common ink chamber 8 are formed together with the narrow groove 14 for the ink supply path.

That is, when the nozzle plate 3 is joined to the liquid chamber forming member 1, bonding is the most common method. At this time, if a large amount of the adhesive runs out to the ink supply path side, the fluid resistance changes and the ink supply performance changes. Or worst case clogging. Particularly, since the narrow groove for the ink supply path is formed in the nozzle plate, when the ink supply path is formed in the liquid chamber forming member 1 in the past, the problem of the protrusion of the adhesive at the time of joining, which was not a problem, became a problem.

Therefore, by forming a side groove on the side of the narrow groove for the ink supply path, the adhesive flowing from the joint is absorbed by the side groove 15 and the flow into the narrow groove 14 for the ink supply path is reduced. Further, since the width of the bonding margin around the ink supply path is reduced, the pressure at the time of bonding effectively acts on the bonding portion, and the sealing property is improved.

Hereinafter, more specific embodiments of the present invention will be described. (Example 1) First, a liquid chamber forming plate 1 in which through holes 7 and 9 were formed in a diaphragm 2 made of a polyimide film having a thickness of 5 μm by etching a stainless plate having a thickness of 100 μm using an epoxy-based adhesive. Joined. At this time, the opening of the through hole 7 of the liquid chamber forming plate 1 was a substantially rectangular shape having a length of 2 mm and a width of 200 μm. The nozzle plate 3 is formed by integrally forming a nozzle hole 11 and a thin groove 14 for an ink supply path as a communication groove by an electroforming method, and is epoxy-bonded to a laminated member of the vibration plate 2 and the liquid chamber forming plate 1. Bonded with the agent. Thereafter, the multilayer piezoelectric element 4 was joined to the outer surface of the vibration plate 2 to assemble an ink jet head.

The nozzle plate 3 was manufactured by electroforming according to the method shown in FIG. First, a negative resist was spin-coated on a stainless steel plate as a conductive substrate 20 having a mirror-finished surface, and prebaked to form a resist layer as a first photosensitive organic film 21 having a thickness of 30 μm. .

Subsequently, exposure is performed using a glass mask patterned with Cr as a first mask 23 in a state in which the glass mask is brought into close contact with the resist layer surface, and areas 21a and 21b corresponding to the nozzle section and the narrow groove for the ink supply path are exposed. did. here,
The nozzle portion was a round pattern having a diameter of 50 μm, and the narrow groove portion for the ink supply path was a slit pattern having a width of 30 μm.

Next, a negative resist layer serving as the second photosensitive organic film 22 is formed again on the resist layer serving as the first photosensitive organic film 21 to a thickness of 30 μm, and an opening pattern having the same shape as the nozzle is formed. Only the nozzle portion was exposed using the second mask 24 having the following. In this embodiment, the nozzle portion was exposed in a circular pattern having a diameter of 30 μm. Thereafter, the organic layer pattern 25 as shown in FIG. 3E was formed on the stainless steel plate by developing the resist layer.

Then, the stainless steel plate was placed in an electroforming tank, and a 50 μm thick Ni layer was formed as a metal film 26 along the organic film pattern 25. After this film formation, subsequently, a thickness of 2 μm was formed by eutectoid plating of Ni and PTFE.
Was formed on the Ni layer. Thereafter, the Ni layer was peeled off from the stainless steel plate, the organic film pattern 25 was removed, and the nozzle plate 3 having the water-repellent layer was obtained by washing.

As a result, it was confirmed that a nozzle plate having a desired shape was obtained, and the dimensions of the nozzle holes 11 and the narrow grooves 14 for the ink supply path were formed with high accuracy of about ± 1 μm with respect to the target dimensions. did it.

Then, an ink jet head was assembled using the nozzle plate 3 and the ejection was evaluated.
It has been found that there is a problem that the ink droplets are not ejected from about 10% of the nozzle holes 11 among the nozzles arranged in a plurality.

Therefore, when the ink jet head was disassembled and its cause was investigated, it was found that the ink supply passage 13 of the non-ejection channel was filled with the adhesive.
Therefore, when the amount of the adhesive at the time of joining the nozzle plates is reduced or an adhesive having a small amount of protrusion is used, ink can be ejected from all the channels.

For comparison, the width of the slit pattern of the ink supply path of the first mask used for the first exposure was set to 60 μm (a width exceeding twice the nozzle depth), and the nozzle plate was made as before. No. 3 was manufactured and its evaluation was performed. As a result, no Ni film was formed on the upper part of the ink supply path.
It could not be used as an inkjet head part.

(Embodiment 2) In Embodiment 1 described above, ink droplets can be ejected from all channels by reducing the amount of adhesive at the time of nozzle plate bonding, but the allowable margin for the bonding conditions is limited. It will be very severe. Therefore, in order to solve the problem of clogging of the ink supply path 13 due to the adhesive, the side grooves 15 are formed on both sides of the ink supply path 13 as shown in FIG. The side groove opening pattern was added to both sides of the slit pattern corresponding to the ink supply path 13 of the first mask used in (1).

The length of the side groove opening pattern is shorter than that of the ink supply path pattern so that the pressure chamber 6 and the common ink chamber 8 do not leak directly when the head is finally assembled.

Example 1 using such a first mask
The nozzle plate 3 having the ink supply path narrow groove 14 having a width of 30 μm was manufactured in the same process as described above, and an ink jet head was assembled.

As a result, even when the clogged adhesive was used in Example 1, ink droplets could be ejected in all channels without clogging the ink supply path 13.

(Embodiment 3) When the frequency characteristics of ink ejection were evaluated using the ink jet head of Embodiment 2 described above, a phenomenon that ink droplets were not ejected in a high frequency region appeared. Therefore, in order to improve the frequency characteristics, the ink supply of the first mask used in FIG. 3B is performed so that two ink supply paths 14 are arranged per channel as shown in FIG. 5 after the electroforming step. The slit pattern corresponding to the path 13 was changed, the nozzle plate 3 was formed in the same process as in Example 2, and the ink jet head was assembled.

Using this ink jet head, the frequency characteristics of ink ejection were evaluated. As a result, good characteristics could be obtained without driving the ink to non-ejection even when driven in a high frequency range.

Next, another ink jet head according to the present invention will be described with reference to FIGS. 7 is an exploded perspective view of the electrostatic ink jet head to which the present invention is applied, FIG. 8 is a top view showing the head in a transparent state, and FIG. 9 is a schematic cross section along the long side direction of the liquid chamber of the head. FIG. 10 is a schematic cross-sectional view along the short side direction of the liquid chamber of the head.

This ink jet head includes a vibration plate / liquid chamber substrate 31, an electrode substrate 33 provided below the vibration plate / liquid chamber substrate 31, and a nozzle plate 34 provided above the vibration plate / liquid chamber substrate 31. And a plurality of nozzles 35, each nozzle 35
A liquid chamber (ejection chamber) 36 which is an ink flow path which communicates with the ink chamber, a common ink chamber 38 which communicates with the liquid chamber 36 via an ink supply path 37 which is a fluid resistance part, and the like are formed.

The vibrating plate / liquid chamber substrate 31 has a liquid chamber 36, a vibrating plate 40 serving as a bottom of the liquid chamber 36, a concave portion forming a partition 41 separating the liquid chambers 36, and a concave portion forming a common ink chamber 38. And so on. Such a vibration plate / liquid chamber substrate 31 diffuses an impurity such as boron to a thickness (depth) serving as a vibration plate in a silicon substrate, for example, and performs anisotropic etching using this impurity diffusion layer as an etching stop layer. It is obtained by forming a concave portion or the like that becomes the liquid chamber 36.

A concave portion 44 is formed in the electrode substrate 33,
A predetermined gap 46 is provided between the diaphragm 40 and the bottom surface of the concave portion 44.
The electrode 45 and the vibrating plate 40 form an actuator unit that displaces the vibrating plate 45 to change the internal volume of the liquid chamber 36.
SiO ₂ is provided on the electrode 45 of the electrode substrate 33 to prevent the electrode 45 from being damaged by contact with the vibration plate 40.
And the like. The electrode 45 is extended to near the end of the electrode substrate 43 to form an electrode pad portion 45a for connecting to an external drive circuit via a connection means.

The electrode substrate 33 is formed by forming a concave portion 44 by etching with a HF aqueous solution or the like on a glass substrate or a Si substrate having a thermal oxide film 33a formed on the surface thereof. Is formed by depositing an electrode material having a desired thickness to a desired thickness by a deposition technique such as sputtering, CVD, or vapor deposition, and then forming and etching a photoresist to form an electrode 45 only in the concave portion 44. . The electrode substrate 33 and the diaphragm / liquid chamber substrate 31 are joined by a process such as anodic joining or direct joining.

The nozzle plate 34 has a nozzle 35 and a liquid chamber 36.
And a common ink chamber 38, a groove portion serving as an ink supply path 37, and an ink tank connection port 49 for connection to an ink tank outside the head (not shown) are also formed. The nozzle plate 34 is formed from a Ni plating film by an electroforming method in the same manner as the above-described ink jet head, and a plating film is formed on the nozzle surface (surface in the ejection direction) to secure water repellency with ink. Alternatively, a water-repellent film is formed by a known method such as a water-repellent coating.

In this ink jet head, the diaphragm is charged by applying a drive voltage between the diaphragm 40 and the electrode 45 (one is a common electrode and the other is an individual electrode), and the diaphragm is charged by electrostatic force. The diaphragm 40 is deformed to the electrode 45 side, and subsequently, the electric charge between the diaphragm 40 and the electrode 45 is discharged, whereby the diaphragm 40 is deformed to return to the liquid chamber 3.
The change in the internal volume (volume) / pressure of 6 causes ink droplets to be ejected from the nozzles 35 and ink to be replenished from the common ink chamber 38 through the ink supply path 37. In this case, it can be driven by either a non-contact driving method in which the diaphragm 40 does not contact the electrode 45 or a contact driving method in which the diaphragm 40 contacts the electrode 45.

By forming the ink supply path in the nozzle plate as described above, it becomes possible to form the diaphragm / liquid chamber substrate including the liquid chamber which does not require the same precision as the ink supply path by anisotropic etching. Cost can be reduced.

As described above, according to the ink jet head of the present invention, since the nozzle hole and the groove forming the ink supply path are formed in the same member, the ink which requires high precision processing is required. The communication groove as the supply path and the nozzle hole can be integrally formed in the same component, and a head with a simple configuration can be obtained at low cost. Improvement can be easily achieved.

Further, according to the ink jet head of the present invention, since a plurality of ink supply paths are formed for one pressure chamber, the ability to supply ink to the pressure chamber is improved.

Further, according to the ink jet head of the present invention, since the groove which is not communicated with the pressure chamber and the common ink chamber is formed on the side of the ink supply path, the ink supply path at the time of adhesive bonding is formed. Clogging can be prevented.

Further, according to the ink jet head of the present invention, a groove forming an ink supply path is formed in a member forming a nozzle, and a plurality of ink supply paths are formed for one pressure chamber. In addition, since a groove that does not communicate with the pressure chamber and the common ink chamber is formed on the side of the ink supply path, a head having a simple structure can be obtained at low cost, and the reliability is improved.

When forming a groove for forming an ink supply path in a member for forming a nozzle, the width of the groove for forming the ink supply path is set to be twice or less the depth of the nozzle.
The reliability at the time of manufacturing the member forming the nozzle by the electroforming method is improved.

According to the method of manufacturing an ink-jet head according to the present invention, in the method of manufacturing an ink-jet head in which a groove for forming an ink supply path is formed in a member for forming a nozzle, the first photosensitive substrate is provided on the electroformed support substrate. After forming an organic film, exposing the first photosensitive organic film through a first mask, forming a second photosensitive organic film on the first photosensitive organic film, After exposing the photosensitive organic film through a second mask, the first and second photosensitive organic films are developed to form a laminated organic film pattern corresponding to a portion where a nozzle and a groove are to be formed, Next, since the metal film is formed on the electroformed support substrate by the electroforming method, the groove forming the nozzle and the ink supply path can be formed with high precision in the member forming the nozzle.

In this case, by forming a water-repellent layer on the surface after forming the metal film, the ink droplet ejection characteristics are improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional explanatory view of a piezo-type inkjet head according to a first embodiment of the present invention.

FIG. 2 is an explanatory plan view showing the nozzle plate of FIG. 1 in a transparent state;

FIG. 3 is an explanatory view illustrating a manufacturing process of a nozzle plate.

FIG. 4 is an explanatory diagram for explaining a relationship between an ink supply path pattern and a nozzle depth;

FIG. 5 is an explanatory plan view similar to FIG. 2, illustrating a second embodiment of the present invention;

FIG. 6 is an explanatory plan view similar to FIG. 2, illustrating a third embodiment of the present invention;

FIG. 7 is an exploded perspective view of the electrostatic inkjet head according to the present invention.

FIG. 8 is an explanatory top view showing the nozzle plate of the head in a transmission state;

FIG. 9 is a schematic cross-sectional explanatory view of the head along the liquid chamber long side direction.

FIG. 10 is a schematic cross-sectional explanatory view along the liquid chamber short side direction of the head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid chamber formation plate, 2 ... Vibration plate, 3 ... Nozzle plate, 4 ... Piezoelectric element, 6 ... Pressure chamber, 8 ... Common ink chamber, 11 ... Nozzle hole, 13 ... Ink supply path.

Claims (7)

[Claims] 1. A nozzle, a pressure chamber with which the nozzle communicates,
An ink jet head including a common ink chamber for supplying ink to a pressure chamber via an ink supply path, wherein the nozzle hole and the groove forming the ink supply path are formed in the same member. head. 2. A nozzle, a pressure chamber with which the nozzle communicates,
An ink jet head comprising a pressure chamber and a common ink chamber for supplying ink via an ink supply path, wherein a plurality of the ink supply paths are formed for one pressure chamber. 3. A nozzle, a pressure chamber with which the nozzle communicates,
In an inkjet head including a pressure chamber and a common ink chamber for supplying ink via an ink supply path, a groove not communicating with the pressure chamber and the common ink chamber is formed on a side of the ink supply path. Characteristic inkjet head. 4. The ink jet head according to claim 2, wherein a groove forming the ink supply path is formed in a member forming the nozzle. 5. The ink jet head according to claim 1, wherein a width of a groove forming the ink supply path is twice or less a depth of the nozzle. 6. A method for manufacturing an ink-jet head according to claim 1, wherein a first photosensitive organic film is formed on an electroformed support substrate. After exposing the photosensitive organic film through the first mask, a second photosensitive organic film is formed on the first photosensitive organic film, and the second photosensitive organic film is exposed to the second mask. After the exposure, the first and second photosensitive organic films are developed to form a laminated organic film pattern corresponding to the portions where the nozzles and grooves are to be formed. A method for manufacturing an ink jet head, comprising: forming a metal film on a substrate by electroforming. 7. The method for manufacturing an ink jet head according to claim 6, wherein a water-repellent layer is formed on the surface after forming the metal film.