JPH0976505A - Inkjet head, method of manufacturing the same, and inkjet recording apparatus - Google Patents

Abstract

(57) Abstract: It is possible to prevent damage to a head and to provide a large number of electrodes of the same shape with good uniformity and little variation, and there is no mutual interference of electric fields between adjacent electrodes. (EN) Provided is an inkjet recording device capable of high-quality recording by forming a stable ink layer on the tip of a head. SOLUTION: In an inkjet recording apparatus for recording by aggregating a colorant component in an ink in which a colorant is dispersed in a solvent and flying it onto a recording medium, a recording medium 1
A convex electrode 102 having an ink guide groove 103 formed from the bottom portion to the tip portion is formed on the wall surface of the head substrate 101 facing the head substrate 101, and the ink 107 is supplied to the head substrate 101 while the convex electrode is formed. By applying a signal voltage to the electrode 102, the colorant component in the ink is conveyed toward the tip of the convex electrode 102 along the ink guide groove 103 and is made to fly from the tip to the recording medium 115.

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 for producing a recording by aggregating a colorant component in an ink having a colorant dispersed in a solvent and flying it on a recording medium, a method for producing the same, and an inkjet. Recording device

[0002]

2. Description of the Related Art In recent years, with the development of computer technology and the progress of information-oriented society, as one of the information output devices, liquid ink is mainly made into droplets, liquid columns, or mist to fly in the air. 2. Description of the Related Art Inkjet printers for recording characters, graphs, images, etc. on recording media such as recording paper have been actively developed. Inkjet printer features include:
Since ink is ejected for recording, it is basically non-contact and non-impact recording with less noise, and since it is direct recording using ink, it does not require complicated processing such as development and fixing like an electrophotographic printer. However, it is possible to record on plain paper, and since ink drops of color inks can be superposed, it is possible to relatively easily perform high-quality color recording.

There are various methods of ink jet printers, but a bubble jet method in which air bubbles are instantaneously generated by a heat generating resistance element and ink is ejected by the pressure of the air bubbles (Harimin et al., The Institute of Image Electronics Engineers of Japan, vol.11, 2 (19
82)) or a method in which an electric signal is converted into mechanical vibration using a piezoelectric element or an electrostrictive element to generate a pressure pulse, and ink is ejected by this pressure pulse (E.Stemme et.al., IEEE Tran.
s.ED20-1, p14 (1973)) is a typical example.

In each of these ink jet printers, ink nozzles are used. However, when the size of the ink nozzles is reduced by increasing the number of nozzles in order to increase the resolution, the ink nozzles will be liable to evaporate due to solvent evaporation. Clogging is likely to occur, which is a major cause of deterioration in reliability. For example, in the bubble jet method, bubbles generated by high-temperature vapor that is generated momentarily are used as a pressure source. However, solid matter may adhere to the nozzle wall due to thermal or chemical reaction due to high temperature between the nozzle and ink. Is a problem. Further, in the method using a piezoelectric element or an electrostrictive element, clogging easily occurs due to a complicated mechanism such as an ink path.

In recent years, there is an increasing need for printers with higher resolution, but it is difficult to form ink droplets having a diameter of 20 μm or less by the conventional bubble jet method, and only a minimum dot diameter of about 50 μm on the recording medium is possible. There was a drawback that it could not be obtained.

As a method for solving these problems, FIG.
A high voltage is applied between the thin film electrode and the counter electrode on the back surface of the recording paper as shown in Fig. 6, and the ink column (droplet) is drawn out from the thin slit by electrostatic attraction, or the charged color as shown in Fig. 6. There is a method (WO93 / 11866: PCT / AU92 / 00665) in which the density of a color material is increased and the ink is ejected using an ink containing a material component. The former is a slit-shaped nozzle that does not require a nozzle for each dot, and the latter is a nozzleless system, which can reduce the problem of clogging, and can stably generate and fly ink droplets with a minute particle size. Because it is possible
Higher resolution is possible.

However, in the heads of these electrostatic ink jet printers, as shown in FIGS. 5 and 6, the tips of the electrode arrays 42 and 52 are projected or almost contacted with the end surfaces of the head substrates 41 and 51. Since it is provided, there is a drawback that recording paper or the like is easily damaged by contact with the electrode array in the printer assembly. Further, from the viewpoint of the head manufacturing method, there is a problem in processing accuracy, uniformity, and yield because it is not possible to use high-precision manufacturing technology such as that found in semiconductor manufacturing processes, such as stepper exposure technology. In particular, since the radius of curvature of the tip of the head is appropriately small and cannot be manufactured uniformly, it is necessary to apply a high voltage to the tip of the head, which hinders low voltage driving, and also causes non-uniformity in shape. I had a problem of abnormal discharge.

Further, in order for the ink to be concentrated and aggregated at the tip of the head to fly, it is necessary that the ink layer is stably formed at the tip of the head due to capillarity or the like. It was difficult to stably form the ink layer at the tip of the head formed in step 1 because the effect of gravity was not equivalent at the tip of the head.

[0009]

As described above, in the conventional ink jet printer head for ejecting the color material component in the liquid ink by the electrostatic force, the electrode array is located on the end face of the head substrate. In the assembly, recording paper etc. is likely to be damaged by contact with the electrode array in the assembly, and it is not possible to use high-precision manufacturing technology found in the semiconductor manufacturing process in head manufacturing, so processing accuracy, uniformity and yield are improved. There was a problem. Especially,
Since the radius of curvature of the tip of the head is reasonably small and it is not possible to make it uniform, it is necessary to apply a high voltage to the head tip, which hinders low-voltage drive, and at the same time causes abnormalities due to shape non-uniformity. There is a problem of discharge, and further, in order for ink to concentrate and coagulate at the tip of the head to fly, it is necessary that the ink layer is stably formed at the tip of the head due to capillarity, etc. However, there is a problem that it is difficult to stably form the ink layer because the influence of gravity is not equivalent at the head tip.

The present invention has been made to solve the above-mentioned problems, and prevents damage to the head when ink-jet recording is performed by aggregating the colorant components in the ink by electrostatic force and causing the components to fly to the recording medium. In addition, it is possible to provide a large number of heads of the same shape with good uniformity and little variation, and a stable ink layer is formed at the head tip to enable high-quality recording, and high integration is easy. It is an object of the present invention to provide an inkjet head, a method of manufacturing the inkjet head, and an inkjet recording apparatus that have high productivity.

[0011]

In order to solve the above problems, the ink jet head according to the present invention causes the colorant component in the ink in which the colorant is dispersed in the solvent to aggregate and fly onto the recording medium. An inkjet head used in an inkjet recording apparatus for recording by:
A head substrate provided to face the recording medium, a convex electrode provided on the head substrate and having a groove formed in the wall surface from the bottom to the tip, and at least the convex electrode on the head substrate. Ink supply means for supplying the ink is provided in the vicinity.

The method of manufacturing an ink jet head according to the present invention comprises the steps of forming a recess on the first main surface of the first substrate, and forming an etching stopper layer on the first main surface including the recess. , A step of forming at least one streak-shaped convex portion along the depth direction of the concave portion on the etching stopper layer in the concave portion, and forming an electrode layer on the etching stopper layer so as to fill the concave portion of the etching stopper layer. The step of forming, the step of providing the second substrate on this electrode layer, the step of removing the first substrate, and the step of removing the etching stop layer and the convex portion to expose the electrode layer to deal with the convex portion And a step of forming a convex electrode having a groove.

[0013] The ink jet recording apparatus according to the present invention comprises:
An ink jet recording apparatus for recording by aggregating a colorant component in an ink in which a colorant is dispersed in a solvent and flying it onto a recording medium, wherein a head substrate provided facing the recording medium, A convex electrode having a groove formed from the bottom to the tip is formed on the wall surface, ink is supplied to at least the vicinity of the convex electrode on the head substrate, and at least the coloring agent component in the ink is at least It is characterized in that the recording medium is transported along the groove toward the leading end so as to fly toward the recording medium from the leading end.

More specifically, the ink jet recording apparatus according to the present invention is provided with a head substrate which faces the recording medium, and a head substrate which is provided on the head substrate and is formed on the wall surface from the bottom to the tip. A convex electrode having a groove, an ink supply means for supplying ink to at least the vicinity of the convex electrode on the head substrate, and at least a coloring agent component in the ink supplied on the head substrate by the ink supply means. Voltage applying means for applying to the convex electrode a voltage according to an image signal to fly from the tip of the electrode to the recording medium.

More specifically, the ink jet recording apparatus according to the present invention performs ink jet recording by aggregating the colorant components in the ink in which the colorant charged to a predetermined polarity is dispersed and flying on the recording medium. In a recording device, a head substrate provided to face a recording medium, a convex electrode provided on the head substrate and having a groove formed in a wall surface thereof from a bottom portion to a tip portion, and a head substrate Of the ink, the ink supplying means supplying ink to at least the vicinity of the convex electrode, and at least the colorant component in the ink supplied onto the head substrate by the ink supplying means flies from the tip of the convex electrode toward the recording medium. A voltage applying unit that applies a voltage corresponding to an image signal having the same polarity as the charging polarity of the coloring material to the convex electrode.

In the present invention, the shape of the convex electrode may be, for example, a quadrangular pyramid, a cone, or a spindle shape, or a Mexican pyramid in which the tip of the quadrangular pyramid is cut off. It is not necessary that the tip of the electrode is sharp, as long as the tip of the electrode is stably wet with the ink and the electric field for the aggregation and flight of the ink can be sufficiently applied. Further, the cross-sectional shape of the groove formed in the convex electrode can be variously selected, such as a hemispherical shape, a trapezoidal shape, and a V shape, as long as the ink is sufficiently supplied to the tip of the convex electrode due to the capillary phenomenon. it can. The width of the groove is preferably 0.1 μm or more on average.

On the other hand, the layer forming the stripe-shaped convex portion is preferably made of resist, glass, or a head conductive material and a metal capable of being selectively etched. Further, as the etching stop layer, for example, when a silicon single crystal substrate is used as the first substrate, the surface including the inside of the recess may be formed by thermal oxidation,
Alternatively, it may be formed by another method. In particular, the use of the thermal oxidation method is preferable because the process consistency with a general semiconductor manufacturing process and the like and the simplification of the process can be achieved.

As described above, in the present invention, the ink jet head is constructed by forming the convex electrode having the groove formed from the bottom portion to the tip portion on the wall surface on the head substrate, and at least the convex electrode on the head substrate is formed. To perform recording by supplying ink in which a colorant is dispersed in a solvent near the electrode and causing at least the colorant component in the ink to fly over the head substrate, that is, from the main surface of the substrate toward the recording medium. Damage to the head tip of a head assembly such as a conventional inkjet head having a head formed on the end surface of the head substrate is prevented.

Further, since the convex electrode, which is the head tip, is provided on the surface of the head substrate, a highly accurate semiconductor processing process which cannot be used in the conventional technique of providing the head tip on the end surface of the head substrate is performed. The manufacturing method used facilitates realization of a multi-head such as a line head in which a large number of convex electrodes having the same shape are formed with good uniformity and little variation. In particular, according to the method of manufacturing an inkjet head of the present invention, since the radius of curvature of the head tip can be made appropriately small and uniform, it is not necessary to apply a high voltage to the head tip, and at the same time low voltage driving is possible, It is possible to prevent abnormal discharge due to non-uniform shape.

In order for the colorant components in the ink to aggregate and fly, it is necessary that the ink layer is stably formed at the tip of the head due to capillarity, and the colorant components aggregate. In order to fly, the ink layer needs to be stably formed at the tip of the head due to capillarity or the like, but in the present invention, the wall surface of the convex electrode, which is the tip of the head, extends from the bottom to the tip. Since the groove is formed in this way, it is possible to stably form an ink layer that reaches this tip sufficiently, and it is possible to realize an ink jet recording apparatus with high performance and high resolution.

Further, in the method of manufacturing an ink jet head according to the present invention, the etching stopper layer and the streak-shaped layer formed along the accurate shape of the recess and the inner surface of the recess formed by photolithography, anisotropic etching or the like. Since the head is formed by using the convex portion as a prototype and filling the electrode layer with the convex portion, it is possible to form the convex electrode shape including the concave groove with high accuracy and in a fine pattern. it can. If the etching stop layer is an insulating layer formed by a thermal oxidation method, the tip of the first concave portion is sharpened due to the growth action of the thermal oxide insulating layer formed in the first concave portion into the first concave portion. Therefore, sharpen the tip of the head,
Moreover, a uniform shape can be obtained. According to the inkjet head manufactured in this manner, ink ejection performance and reliability are significantly improved.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to an embodiment of the present invention. In the figure, a head substrate 101 is an insulating substrate such as a glass substrate, and a convex electrode 102 and its extraction electrode 104 are formed on the head substrate 101. Here, the convex electrode 102 is provided with an ink guide groove 103 formed on the wall surface from the bottom to the tip. The end of the lead electrode 103 opposite to the side connected to the convex electrode 102 is exposed to the outside. An upper cover 106 having an ink droplet ejection port 105 at a position corresponding to the convex electrode 102 is arranged above the head substrate 101.

FIG. 2 is an enlarged view showing a part of FIG. 1 in the case where a multi-head such as a line head is constructed.
A plurality of convex electrodes 102 are provided on the head substrate 101 along the main scanning direction X. Further, as shown in the figure, in this embodiment, the shape of the convex electrode 102 is a pyramid shape, and the tip thereof is sharp. The ink guide groove 10 is formed on each wall surface of the pyramid of the convex electrode 102.
3 are formed. Also, in this example, the ink guide groove 1
03 has a narrower shape as it approaches the tip from the bottom.

The ink 107 used in this embodiment is, for example, a colloidal dispersion of a positively chargeable coloring agent together with a charge control material and a binder in an insulating solvent of 10 ⁸ Ωcm or more. The agent is assumed to be positively charged. The ink 107 is supplied onto the head substrate 101 from an ink supply port 110 via an ink flow path 109 by an ink recirculation mechanism 108 including an ink tank and a pump.

Ink 1 supplied on the head substrate 101
07 flows on the surface of the head substrate 101 along the sub-scanning direction Y (relative movement direction of the recording medium), and a part of the convex electrode 1
Reach 02. Ink 10 reaching the convex electrode 102
7 rises by the capillary phenomenon along the ink guide groove 103 formed on the wall surface of the convex electrode 102, and reaches the tip of the convex electrode 102, which is the flight point of the ink droplet. Of the ink 107 supplied on the head substrate 104, the ink that has not reached the convex electrodes 102 is the ink recovery port 11
It is collected by the reflux mechanism 108 from 1 through the ink flow path 109.

The above-mentioned head substrate 101, the convex electrode 102 having the ink guide groove 103, the lead electrode 104,
An ink jet head is composed of an upper cover 106 having an ink droplet ejection hole 105, an ink recirculation mechanism 108, and an ink flow path 109 having an ink ejection port 110 and an ink ejection port 111.

A drive circuit 112 is provided on the extraction electrode 104.
And the DC bias power supply 113 is connected in series. The drive circuit 112 generates a signal pulse voltage with a positive polarity of, for example, 200 V that is turned on / off in accordance with an image signal to be recorded, and this is superimposed on a bias voltage of, for example, DC 1 kV supplied from the DC bias power source 113, and the extraction electrode. It is applied to the convex electrode 102 via 103.

That is, the ink 10 is formed on the convex electrode 102.
A voltage having the same polarity as the charging polarity of the coloring material in 7 is applied.
Therefore, the aggregated colorant component in the ink 107 that has reached the tip of the convex electrode 102 is electrostatically repulsive, and thus the head substrate 1
The ink droplets 114 are ejected in a direction substantially perpendicular to the surface 01. The ejected ink droplets 114 pass through the ink droplet ejection holes 105 provided in the upper cover 106, and are directed toward the recording paper 115, which is a recording medium that is arranged to face the head substrate 101 via the upper cover 106. hand,
Counter electrode 1 provided on the back surface of the recording paper 115 and having a ground potential
The recording paper 115 is pulled by 16 and flies.
To reach the top. As a result, an image is recorded on the recording paper 115.

As described above, in the ink jet recording apparatus of this embodiment, the recording paper 11 is used in the ink jet head.
5 can be provided on the main surface of the head substrate 101 instead of the end surface of the head substrate 101, which is the head end of the head, so that the convex electrode 102 is unlikely to be damaged due to contact with the recording paper 115. .

Further, since the ink guide groove 103 is provided on the wall surface of the convex electrode 102, the ink is guided to the tip of the convex electrode 102 by a capillary phenomenon or the like,
The ink layer is easily and stably formed, and a high-performance and high-quality inkjet recording device can be realized.

Incidentally, a part or the whole of the surface of the convex electrode 102 may be covered with an insulating layer while maintaining the groove shape of the ink guide groove 103. In short, an electric field sufficient for the ink 107 to be aggregated and fly. It is sufficient that it can be applied to the ink 107. Further, the coloring material in the ink 107 may be negatively charged, and in that case, the extraction electrode 10 is used.
The polarity of the voltage applied to the convex electrode 102 via 4 may be made negative.

Next, a method of manufacturing the ink jet head according to this embodiment will be described. FIG. 3 is a cross-sectional view showing the manufacturing process of the inkjet head, and particularly shows the forming process of one convex electrode 102 and one ink reservoir 105. In the case of a multi-head, FIG.
Cross section orthogonal to the main scanning direction X, that is, the sub-scanning direction Y
The cross section of FIG.

First, on the first main surface side of the Si single crystal substrate 201, for example, a concave portion having an inverted pyramid shape corresponding to the shape of the convex electrode 102 is formed. As a method of forming such a recess, for example, anisotropic etching of a Si single crystal substrate can be used. That is, first, as shown in FIG. 3A, a SiO ₂ thermal oxide layer 2 having a thickness of 0.1 μm is formed on a p-type (100) crystal plane orientation Si single crystal substrate 201.
02 is formed by a dry oxidation method, and a resist 2 is formed thereon.
03 is applied by a spin coating method. Next, FIG.
As shown in (b), using a stepper, for example, 10 μm
After patterning by exposure, development, etc., so as to obtain the square-shaped opening 204 having a square shape, the SiO ₂ thermal oxide layer 202 is etched with a NH ₄ F / HF mixed solution.
Then, after removing the remaining resist, for example, 30 wt
% KOH aqueous solution is used to perform anisotropic etching to form an inverted pyramidal recess 205 having a depth of 7.1 μm on the Si single crystal substrate 201 as shown in FIG. 3C.

Next, using a mixed solution of NH ₄ F and HF,
After the SiO ₂ oxide layer 202 is once removed, as shown in FIG. 3D, the Si single crystal substrate 201 including the inside of the recess 205 is included.
The SiO ₂ thermally-oxidized insulating layer is formed on the upper surface of the etching stopper layer 2 so that the concave portion 205 has a recessed shape along the inner surface thereof.
It is formed as 06. In this embodiment, the etching stop layer 206 made of a SiO ₂ thermal oxidation insulating layer has a thickness of 0.3.
It was formed by the Wet oxidation method so as to have a thickness of about μm. In this case, the etching layer 206 has a structure in which the central portion in the depth direction of the recess 205 swells on the inner surface of the recess 205 as shown in FIG. The tip of the convex electrode 102 can be sharpened. As a result, it is possible to enhance the effect of electric field concentration on the tip of the convex electrode 102 and promote high resolution and low voltage driving.

Then, as shown in FIG. 3 (e), the recess 2 is formed.
On the inner surface of 05, a streak-shaped convex portion 207 is formed by vapor deposition using glass, for example. Next, the convex electrode 102 and the extraction electrode 10 are formed on the etching stop layer 206 made of the SiO ₂ thermal oxidation insulating layer and the streak-shaped convex portion 207.
For example, a molybdenum layer, a tantalum layer, or a chromium layer is formed as the electrode layer 208 to be 4 so as to fill the recess 205. In this embodiment, a molybdenum layer is formed as the electrode layer 208 by a sputtering method so as to have a thickness of 5 μm. At this time, sputtering is performed using a mask so that the electrode layer 208 is selectively formed substantially in the portions that will become the individual electrodes 102 and the extraction electrodes 104 in the sub-scanning direction. Depending on the material and conductivity of the electrode layer 208, the wettability with ink may be taken into consideration, and the IT
It may be formed by stacking conductive layers such as an O layer.

When it is required to make the shape of the convex electrode 102 large, that is, when the size or depth of the opening of the concave portion 205 becomes large, the electrode layer 208 is formed sufficiently thick to form the concave portion. It may be difficult to completely fill the inner part 205. In such a case, the electrode layer 20
And a concave portion 205 is formed by forming a core material layer made of another single material or a plurality of materials from the first main surface side of the Si single crystal substrate 201 on
Fill the inside.

Next, as shown in FIG. 3F, a Pyrex glass substrate 209 is formed on the electrode layer 208 so as to extend over the electrode layers 208, by using, for example, an electrostatic bonding method, to form a Si single crystal substrate 201. Adhesion is performed so as to interpose the electrode layer 208.
Then, the Pyrex glass substrate 209 is used as the head substrate 101 as it is, or a relatively thick glass substrate is adhered thereto to form the head substrate 101.

The electrode layer 208 is sufficiently thick,
When sufficient strength as a structural material can be obtained, as shown in FIG.
It is possible to omit the step (g) and directly bond the electrode layer 208 to the head substrate 101.

Next, as shown in FIG. 3 (g), the Si single crystal substrate 201 is removed by etching with a mixed aqueous solution of ethylenediamine, pyrocatechol and pyrazine, and then the thermal oxide layer and the streak-shaped convex glass are removed with NH _4. It is removed using various mixed acids such as F / HF or an HF aqueous solution. As a result, as shown in FIG. 3G, a concave groove 210 is formed in the electrode layer 208, and the pyramidal convex electrode 10 having the ink guide groove 103 as shown in FIGS. 1 and 2 is formed.
2 is formed.

As described above, the ink jet head according to the embodiment has the concave portion 20 formed by anisotropic etching.
After forming an etching layer 206 made of a SiO ₂ thermal oxidation insulating layer on the Si single crystal substrate 201 having No. 5, the concave electrode 205 is filled with the electrode layer 208 to form the convex electrode 102. Therefore, the convex electrode 102 having excellent uniformity and reproducibility can be formed according to the shape of the concave portion 205.

Further, the concave portion 20 is formed by anisotropic etching.
Since the shape reproducibility of No. 5 and the growth action of the SiO ₂ thermally-oxidized insulating layer serving as the etching stop layer 206 in the recess 205 can make the bottom of the recess 205 into a well-pointed inverted pyramid shape, It is possible to stably form the convex electrode 102 having a significantly enhanced electric field concentration effect on the electrode. As a result, unlike the prior art, it is not necessary to apply a high voltage to the convex electrode 102 that is the tip of the head, it is possible to drive at a low voltage, and at the same time, it is possible to prevent abnormal discharge due to shape nonuniformity. It will be possible. In addition, since the thermal oxidation method has good process compatibility with general semiconductor manufacturing processes,
It is also possible to simplify the process.

In order for the ink droplets to aggregate and fly, it is necessary that an ink layer is stably formed at the tip of the convex electrode 102, which is the tip of the head, by capillarity or the like. Since the concave-shaped ink guide groove 103 is formed on the wall surface of the electrode 102, the ink on the head substrate 102 climbs to the tip of the convex electrode 102 due to the capillary phenomenon, and the ink layer can be stably formed at the tip. Therefore, the ink ejection performance and reliability can be significantly improved.

In the above embodiment, the ink guide groove 103 is provided on the wide wall surface of the pyramidal convex electrode 102. However, as shown in FIG. 4A, the ink guide groove 103 is formed at the position where the ridge line of the pyramid is formed. 103 may be formed. Further, the shape of the convex electrode 102 does not have to be a pyramid shape, but may be a cone shape as shown in FIG. 4B, for example, and the ink guide groove 103 may be formed on the wall surface of this cone.

[0044]

As described above, according to the present invention, the convex electrode having the groove formed on the wall surface from the bottom to the tip is formed on the head substrate, and at least the convex electrode on the head substrate is formed. The ink is supplied in the vicinity of the electrode, and at least the colorant component in the ink is conveyed toward at least the tip portion along at least the ink guide groove and is ejected from the tip portion toward the recording medium to perform recording. Therefore, damage to the head tip of a head assembly such as a conventional inkjet head having a head formed on the end surface of the head substrate is prevented.

Further, in the present invention, since the convex electrode that is the tip of the head is provided on the surface of the head substrate, the convex electrode that is the tip of the head is provided on the end face of the head substrate, so that it cannot be used conventionally. By the manufacturing method using the highly accurate semiconductor processing process, it is easy to realize a multi-head in which a large number of convex electrodes having the same shape with good uniformity and less variation are formed. In particular, according to the method of manufacturing an inkjet head of the present invention, since the radius of curvature of the head tip can be made appropriately small and uniform, it is not necessary to apply a high voltage to the head tip, and at the same time low voltage driving is possible, It is possible to prevent abnormal discharge due to non-uniform shape.

Further, in order for the coloring agent components in the ink to aggregate and fly as ink droplets, it is necessary that a stable ink layer is formed at the tip of the convex electrode. Since there is an ink guide groove on the wall of the electrode, the ink can be reliably supplied to the tip of the convex electrode due to the capillary phenomenon, and the ink layer can be stably formed. A recording device can be realized.

Further, according to the method of manufacturing the ink jet head of the present invention, the etching stopper layer and the streak formed along the accurate shape of the recess and the inner surface of the recess formed by photolithography, anisotropic etching, etc. Since the head is created by using the convex portions of as a prototype and filling the electrode layer with the convex portions, it is necessary to form the convex electrode shape including the concave groove with high accuracy and finely. You can Further, when the etching stop layer is an insulating layer formed by a thermal oxidation method, the thermal oxidation insulating layer formed in the first recess is allowed to grow in the first recess due to the growth action in the first recess.
Since the tip of the concave portion is sharpened, the head tip can be made sharp and uniform. According to the inkjet head manufactured in this manner, ink ejection performance and reliability are significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a main part of the inkjet head according to the embodiment.

FIG. 3 is a process cross-sectional view for explaining the method of manufacturing the inkjet head according to the embodiment.

FIG. 4 is a diagram showing a configuration of convex electrodes in an inkjet head according to another embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a main part of an inkjet head according to a first conventional example.

FIG. 6 is a perspective view showing a configuration of a main part of an inkjet head according to a second conventional example.

[Explanation of symbols]

 101 ... Head substrate 102 ... Convex electrode 103 ... Ink guide groove 104 ... Extraction electrode 105 ... Ink droplet ejection hole 106 ... Top cover 107 ... Ink 108 ... Ink recirculation mechanism 109 ... Ink flow channel 110 ... Ink supply port 111 ... Ink recovery Hole 112 ... Driving circuit 113 ... Bias power supply 115 ... Recording paper 116 ... Counter electrode 201 ... Si single crystal substrate (first substrate) 202 ... Thermal oxidation layer 203 ... Resist 204 ... Rectangular opening 205 ... Recess 206 ... Etching stop layer 207 ... Streaky convex portion 208 ... Electrode layer 209 ... Glass Pyrex substrate (second substrate) 210 ... Groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruo Murakami 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Research and Development Center (72) Inventor Hideyuki Nakao Komukai-shiba, Kawasaki-shi, Kanagawa Town No. 1 Toshiba Corporation Research & Development Center

Claims (5)

[Claims] 1. An ink jet head used in an ink jet recording apparatus for recording by aggregating a colorant component in an ink in which a colorant is dispersed in a solvent and flying it onto a recording medium, which is opposed to the recording medium. A head substrate provided in the head substrate, and a convex electrode provided on the head substrate and having a groove formed in the wall surface from the bottom to the tip, and at least in the vicinity of the convex electrode on the head substrate. An inkjet head, comprising: an ink supply unit that supplies the ink. 2. A step of providing a recess on the first main surface of a first substrate, a step of forming an etching stopper layer on the first main surface including the recess, and the etching stopper layer in the recess. A step of forming at least one streak-shaped convex portion along the depth direction of the concave portion, and a step of forming an electrode layer on the etching stopper layer so as to fill the concave portion of the etching stopper layer; A step of providing a second substrate on the electrode layer, a step of removing the first substrate, and a step of removing the etching stop layer and the convex portion to expose the electrode layer to form a convex portion on the convex portion. And a step of forming a convex electrode having a corresponding groove. 3. An ink jet recording apparatus for recording by aggregating a colorant component in an ink in which a colorant is dispersed in a solvent and flying it onto a recording medium, wherein a head is provided facing the recording medium. A convex electrode having a groove formed on the wall surface from the bottom to the tip is formed on the substrate, and the ink is supplied to at least the vicinity of the convex electrode on the head substrate, 2. An ink jet recording apparatus, wherein at least the coloring agent component is conveyed along at least the groove toward the tip portion and is made to fly from the tip portion toward the recording medium. 4. An ink jet recording apparatus for recording by aggregating a colorant component in an ink in which a colorant is dispersed in a solvent and flying it onto a recording medium, a head substrate provided facing the recording medium. A convex electrode provided on the head substrate and having a groove formed on its wall surface from the bottom to the tip, and ink for supplying the ink to at least the vicinity of the convex electrode on the head substrate. A supply unit and a voltage according to an image signal for causing at least the colorant component in the ink supplied onto the head substrate by the ink supply unit to fly from the tip of the convex electrode toward the recording medium. An inkjet recording apparatus comprising: a voltage applying unit that applies a voltage to the convex electrode. 5. An ink jet recording apparatus for recording by causing a colorant component in an ink in which a colorant charged to a predetermined polarity is dispersed in a solvent to aggregate and fly onto a recording medium, facing the recording medium. A head substrate provided on the head substrate, a convex electrode having a groove formed on the wall surface of the head substrate from the bottom to the tip, and at least in the vicinity of the convex electrode on the head substrate. Ink supply means for supplying ink, and the color for causing at least the colorant component in the ink supplied on the head substrate by the ink supply means to fly from the tip of the convex electrode toward the recording medium. An ink jet recording apparatus comprising: a voltage applying unit that applies a voltage according to an image signal having the same polarity as the charging polarity of the agent to the convex electrode.