JP2003182070A - Liquid drop ejection head and its manufacturing method, ink cartridge, ink jet recorder, microactuator, micropump, optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a high ejection efficiency cannot be attained at a low cost. <P>SOLUTION: An insulating film 11 is formed on a diaphragm 10 and conductive structures are provided on the surface of the insulating film 11 while being isolated electrically from each other. A plurality of electrodes 14 having a width narrower on the fixed end part 14A side than on the free end part 14B side are provided. The diaphragm 10 is deformed by generating an electrostatic force between the electrodes 14 and 14. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a droplet discharge head and its manufacturing method, an ink cartridge, an ink jet recording apparatus, a micro actuator, a micro pump and an optical device.

[0002]

2. Description of the Related Art An ink jet head, which is a liquid drop ejection head used in an ink jet recording apparatus used as an image recording apparatus such as a printer, a facsimile, a copying machine or an image forming apparatus, has a single or a plurality of nozzle holes for ejecting ink droplets. And a discharge chamber (also referred to as an ink chamber, a liquid chamber, a pressurized liquid chamber, a pressure chamber, an ink flow path, etc.) communicating with the nozzle hole, and a pressure generation for generating a pressure for pressurizing the ink in the discharge chamber. And ejecting ink droplets from the nozzle holes by pressurizing the ink in the ejection chamber with the pressure generated by the pressure generating means.

As the droplet discharge head, for example, a droplet discharge head for discharging a liquid resist as droplets, DN
There is also a droplet discharge head that discharges the sample A as droplets, but in the following, an inkjet head will be mainly described. In addition, a microactuator, such as a micropump, that constitutes the actuator portion of the droplet discharge head,
It can also be applied to optical devices such as micro light modulation devices, micro switches (micro relays), actuators (optical switches) of multi-optical lenses, micro flow meters, pressure sensors, and the like.

By the way, as a droplet discharge head, an electromechanical conversion element such as a piezoelectric element is used as a pressure generating means to deform and displace a vibrating plate forming the wall surface of the discharge chamber to discharge ink droplets. Type, bubble type (thermal type) in which bubbles are generated by film boiling of ink and ink droplets are discharged by using an electrothermal conversion element such as a heating resistor arranged in the discharge, wall surface of discharge chamber There is an electrostatic type in which an ink droplet is ejected by deforming a vibration plate that forms an electrostatic force.

In recent years, a lead-free bubble type and an electrostatic type have been attracting attention due to environmental problems. In addition to lead-free, a plurality of electrostatic types have been proposed which have little influence on the environment from the viewpoint of low power consumption. ing.

In this electrostatic head, a vibrating plate is pushed to the ink chamber side to reduce the internal volume of the ink chamber, thereby driving the ink droplets by a pushing method.
It is a knock-out method that ejects ink droplets by deforming the vibration plate with the force in the outer direction of the ink chamber and returning the displacement of the vibration plate to the original inner volume from the state where the inner volume of the ink chamber is expanded. Some are driven.

As a push type electrostatic head, for example, as described in Japanese Patent Application Laid-Open No. 2-266943, ink is filled between a pair of electrodes, and one or both electrodes are filled. There is a type in which the ink acts as a vibrating plate, and when a voltage is applied between the electrodes, an electrostatic attractive force acts between the electrodes, and the electrodes (vibrating plate) are deformed, whereby the ink is pushed out and ejected. In addition, JP-A-200
As described in Japanese Patent Application Laid-Open No. 0-15805, a protrusion is provided on the surface of a diaphragm made of a silicon substrate, electrodes are formed on the protrusion, and a voltage is applied to the electrodes to act between the protrusions. There is also one that deforms the diaphragm by electrostatic force to eject ink.

As the pulling-out method, for example, Japanese Patent Laid-Open No. 6-7
As described in Japanese Patent No. 1882, a pair of electrodes is provided via an air gap, one electrode functions as a diaphragm, and ink is filled on the opposite side of the diaphragm to the opposing electrode. An ink chamber is formed, and by applying a voltage between the electrodes (between the vibrating plate and the electrode), an electrostatic attractive force acts between the electrodes, the electrodes (vibrating plate) are deformed, and when the voltage is removed, the vibrating plate becomes elastic. Some return to the original state and use the force to eject ink. In addition, JP-A-200
As described in JP-A-1-47624, a vibrating plate is provided on one side of electrode pairs formed in a comb shape and nested with each other, and electrostatic force attractive force is generated between the comb teeth by applying a voltage to the electrode pair. Is generated, the diaphragm is deformed by the displacement of the electrode, and the ink is ejected by the elastic force of the diaphragm when the voltage is cut off.

[0009]

However, in the droplet discharge head described in Japanese Patent Laid-Open No. 2-266943, since the ink is filled between the electrodes, the distance between the electrodes inevitably becomes large. Since the electrostatic force acting between the electrodes is inversely proportional to the square of the distance between the electrodes, there is a problem that the required voltage becomes very large as the distance between the electrodes increases. In this case, the voltage can be lowered to some extent depending on the dielectric constant of the ink, but it is not so effective because the distance between the electrodes has a great influence. In addition, the degree of freedom of the ink decreases because it is necessary to increase the dielectric constant of the ink or an electric field is applied to the ink. Therefore, the ink color, p
There is a problem that it is difficult to achieve high image quality because the physical properties of the ink such as H and viscosity are limited.

Further, in the droplet discharge head described in Japanese Patent Laid-Open No. 6-71882, since ink is not filled between the electrodes, there is less restriction on the ink and it is advantageous for high image quality. However, in order to reduce the voltage, the air gap between the electrodes must be made extremely small, and it is very difficult to form such a minute gap with high accuracy and with little variation, and the yield does not increase. There is such a problem. In addition, since it is a so-called pull-out method in which ink is ejected by the elastic force of the diaphragm, the diaphragm needs to have a rigidity sufficient to eject ink, and a voltage for attracting such a diaphragm with electrostatic force is applied. There is a problem that it becomes high.

Further, in the droplet discharge head described in the above-mentioned Japanese Patent Laid-Open No. 2001-47624, since the comb-teeth-shaped electrode is used, the displacement amount can be increased, but the generated force is very small, If an attempt is made to obtain the force required to eject ink, the voltage will become extremely high. Moreover, since the structure is complicated, it is difficult to manufacture, and the cost increases.

Further, in the droplet discharge head described in the above-mentioned Japanese Patent Laid-Open No. 2000-15805, a vibrating plate formed of a conductive silicon substrate is provided with a protrusion, and the protrusion is provided with a conductive member. Since the electrodes are formed, there is a problem in that the electrodes cannot be deformed because the electrostatic potential is not generated between the electrodes via the silicon diaphragm and the electrostatic potential is not generated.

In addition, it is necessary to form a protrusion on the diaphragm and attach an electrode to this protrusion, and it is difficult to attach an electrode to the surface of such a three-dimensional fine structure, and the electrode is not formed well. There is a problem that a part is formed or variation occurs, stable manufacturing cannot be performed, and yield is low. Furthermore, in order to reduce the voltage, it is necessary to narrow the gap between the protrusions, but it is difficult to form electrodes in such a narrow gap, and if electrodes are formed between the narrow protrusions, short-circuiting occurs. There is a defect that it will happen.

Further, it is not possible to form electrodes on the protrusions by a general method because it is difficult to perform resist coating and exposure in the photolithography process in a three-dimensional structure. Therefore, a special device is used. However, there is a problem that the cost increases due to the increase in manufacturing process and the lengthening of the manufacturing process.

The present invention has been made in view of the above problems, and is a low-cost droplet discharge head capable of high droplet discharge efficiency and high-quality printing, a method of manufacturing the same, and an ink in which the head is integrated. An object of the present invention is to provide a cartridge, an inkjet recording device capable of high-quality recording, a low-cost microactuator having a high driving efficiency, a micropump, and an optical device.

[0016]

In order to solve the above-mentioned problems, a droplet discharge head according to the present invention comprises a vibrating plate having a conductive structure electrically isolated from each other.
A plurality of electrodes whose fixed ends are narrower than the width of the free ends are provided, and the diaphragm is deformed by generating an electrostatic force between the electrodes.

Here, the width of the electrode is preferably changed continuously or stepwise. Further, it is preferable that the electrode is made of polysilicon. Furthermore, it is preferable that an insulating film is formed on the surface of the electrode. In this case, the insulating film on the electrode surface has a substantially uniform film thickness or a film thickness on the fixed end side smaller than that on the free end side. The insulating film is preferably a SiO ₂ film, a Si ₃ N ₄ film, a SiON film, or a SiOF film.
It is preferably one of the membranes.

An insulating film is preferably formed between the diaphragm and the electrode, and the insulating film is preferably a multilayer film. In this case, at least the electrode-side film of the multilayer film is made of silicon. It is preferably an oxide film or a silicon nitride film.

Furthermore, it is preferable that the electrodes are partially narrowed in the direction in which the electrodes are arranged. Further, it is preferable that the intervals between the plurality of electrodes are different in the direction in which the electrodes are arranged. In this case, the intervals between the plurality of electrodes are preferably narrower in the peripheral portion of the diaphragm than in the central portion of the diaphragm. Furthermore, it is preferable that a part of the electrode is formed by a selective CVD method or electroforming.

A method for manufacturing a droplet discharge head according to the present invention is a method for manufacturing a droplet discharge head according to the present invention in which the width of the electrodes is continuously changed, and the electrodes have a groove between the electrodes. It is formed by anisotropic etching.

A method of manufacturing a droplet discharge head according to the present invention is a method of manufacturing a droplet discharge head in which a width of an electrode changes stepwise, and a sacrificial layer is provided in a narrow portion of the electrode. In this state, the groove between the electrodes corresponding to the wide portion is anisotropically etched, and then the sacrificial layer in the narrow portion is removed by wet etching. In this case, it is preferable that the sacrifice layer is a silicon oxide film, and particularly the silicon oxide film is formed by a plasma CVD method.

The ink cartridge according to the present invention is one in which the droplet discharge head according to the present invention for discharging ink droplets and the ink tank for supplying ink to this droplet discharge head are integrated.

The ink jet recording apparatus according to the present invention is
The droplet discharge head according to the present invention for ejecting ink droplets or the ink cartridge according to the present invention is mounted on the tower.

The microactuator according to the present invention is
A microactuator for deforming a movable part, comprising a plurality of electrodes each having a fixed end portion having a width narrower than that of a free end portion, the movable portion being made of a conductive structure electrically isolated from each other. The movable part is deformed by generating an electrostatic force between the electrodes.

A micropump according to the present invention is a micropump that transports a liquid by deformation of a movable part, and includes the microactuator according to the present invention.

An optical device according to the present invention is an optical device that changes the reflection direction of light by displacement of a mirror formed in a movable part, and includes the microactuator according to the present invention.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of an inkjet head according to a first embodiment of a droplet discharge head of the present invention, and is shown in a partial sectional view. 2 is a cross-sectional explanatory view of the same head in the longitudinal direction of the diaphragm, FIG. 3 is a cross-sectional explanatory view of the same head in the lateral direction of the diaphragm, and FIG. 4 is a plan explanatory view showing an electrode arrangement pattern of the same head.

This ink jet head is of a side shooter type in which ink droplets are ejected from nozzle holes provided on the surface of the substrate, and three first, second and third ink jet heads having a structure described in detail below are provided. It has a laminated structure in which the substrates 1, 2 and 3 are stacked and joined, and a plurality of nozzle holes 4 for ejecting ink droplets, an ejection chamber 6 communicating with each nozzle hole 4, and a fluid resistance portion 7 in each ejection chamber 6. A common liquid chamber (common ink chamber) 8 for supplying ink via the same is formed.

The intermediate first substrate 1 is made of a silicon substrate and has a concave portion for forming the discharge chamber 6 having the bottom wall as the vibration plate 10 and a common liquid chamber for supplying ink to each discharge chamber 6. 8 has a recess for forming 8.

The vibrating plate 10 is formed of a high-concentration p-type impurity diffusion layer 10a obtained by doping a silicon substrate to be the first substrate 1 with a high-concentration p-type impurity such as high-concentration boron, and the discharge chamber 6 of the vibrating plate 10 is formed. An insulating film 11 composed of a multilayer film is provided on the surface opposite to the surface. The insulating film 11 is formed by sequentially stacking a silicon nitride film 11a and a silicon oxide film 11b on the surface of the high-concentration p-type impurity diffusion layer 10a.

Then, a plurality of electrodes 14 are formed on the surface of the silicon oxide film 11b forming the insulating film 11 at predetermined intervals, and the diaphragm 10 and each electrode 14 are electrically connected via the insulating film 11. And two electrodes adjacent to each other (each of which is relatively
They are called a and 14b. ) Are electrically isolated from each other.
The electrode 14 is formed of, for example, polysilicon or single crystal silicon. The vibrating plate 10 and the plurality of electrodes 14 constitute a microactuator according to the present invention that deforms the vibrating plate 10 that is a movable part.

Here, in each electrode 14, as shown in FIG. 3 and FIG. 5 described later, the width of the fixed end portion 14A fixed to the diaphragm 10 side in the lateral direction of the diaphragm is the free end portion 14B side. It is formed to be narrower continuously than that. That is, the groove shape between the electrodes 14, 14 is formed such that the groove width becomes wider as the groove becomes deeper (closer to the diaphragm 10 side).

To form such an electrode shape, for example, a silicon nitride film 11a and a silicon oxide film 11b are sequentially formed on a silicon substrate having a (110) plane orientation in which a high concentration boron diffusion layer 10a is formed, and then silicon oxide is formed. After forming a polysilicon film serving as an electrode material on the surface of the film 11b, SF ₆ ,
Grooves between the electrodes are formed by dry etching using HBr and O ₂ gas. As a result, the etching shape is the electrode 1
As the groove between 4 and 14 becomes deeper (closer to the diaphragm 10 side), the groove width becomes wider and becomes an inverse taper shape, and as shown in FIG. 3, an electrode 14 is formed which becomes narrower toward the fixed end 14A side. be able to.

FIG. 4 shows an example of the electrode arrangement pattern for one diaphragm when viewed from the electrode 14 side of the first substrate 1. As shown in the figure, a driving voltage (a voltage having a different potential) that causes a potential difference from each other is applied from a driving circuit (here, shown as a transmission circuit) 15 to the electrodes 14a and 14b that are electrically separated from each other. It is supposed to be done.

Further, a spacer 12 which is a layer or a structural body made of the same material as the electrode 14 is provided on the electrode 1 in a region other than the vibrating plate 10.
It is formed on the substantially same plane as the surface forming 4. The spacer 12 can be formed simultaneously with the electrode 14, and can be formed by not removing the electrode material other than the vibrating plate region.

By providing such a spacer 12, the electrode 14 which is a minute structure can be protected in the process before the first substrate 1 is bonded to the second substrate 2, and the wafer transfer and Therefore, defects due to breakage of the electrode 14 during the process can be reduced.

The second substrate 2 bonded to the lower surface of the first substrate 1 is a protective substrate for protecting the electrode 14 from external impacts and dust, and for reinforcing the strength of the first substrate 1. Is. A substrate made of glass, metal, silicon, resin, or the like is used as the second substrate 2, and a concave portion 16 having a depth of, for example, 1 mm is formed on the substrate 2 at a position corresponding to each diaphragm 10. There is. However, it is not always necessary to form the concave portion 16 for each diaphragm 10, and it is also possible to form a concave portion that surrounds the diaphragm arrangement or a concave portion that is joined only to the edge of the chip.

The third substrate bonded to the upper surface of the first substrate 1
For the substrate 3, for example, a nickel substrate having a thickness of 50 μm is used, and a fluid resistance portion for communicating the nozzle hole 4, the common liquid chamber 8 and the discharge chamber 6 with the surface portion of the third substrate 3 so as to communicate with the discharge chamber 6, respectively. 7 is provided, and an ink supply port 9 is provided so as to communicate with the common liquid chamber 8.

The operation of the ink jet head thus configured will be described. For example, in the configuration of FIG.
When a pulse potential of 0V to 40V is applied to 4a by the oscillating circuit 15, the surface of the electrode 14a is positively charged, and as shown in FIG. 5, it is statically charged between adjacent electrodes 14b to which the pulse potential is not applied. Electric power is generated, electrostatic attraction works, the free ends of the electrodes 14 (the fixed end on the diaphragm 10 side) attract each other, and the electrodes 14 are displaced.
The displacement of the free end of the electrode causes the diaphragm 10, which is the fixed end of the electrode 14, to bend upward. As a result, the pressure in the ejection chamber 6 rapidly increases, and the ink droplets 22 are ejected from the nozzle holes 4 toward the recording paper 23 as shown in FIG.

When the potential of the electrode 14a returns to 0V, the potential difference between the electrode 14b and the electrode 14b disappears, and the vibration plate 10
Restores the original state. When the vibration plate 10 is restored, ink is replenished from the common liquid chamber 8 into the ejection chamber 6 through the fluid resistance portion 7. That is, in this embodiment, the ink droplets are ejected by the pushing method.

Here, the force F acting between the electrodes is calculated by the following (1)
As shown in the formula, it increases in inverse proportion to the square of the inter-electrode distance d. In order to drive at a low voltage, the electrode 14a and the electrode 1
It is important to form a narrow gap between the electrodes 4b, that is, a groove between the electrodes 14.

[0042]

[Equation 1]

In the equation (1), F: force acting between electrodes, ε: permittivity, S: area of facing surfaces of electrodes, d:
Distance between electrodes, V: applied voltage.

As described above, in this ink jet head, the electrodes 14 that are electrically separated and independent from each other are provided on one surface of the vibration plate 10 through the insulating film 11.
By applying a voltage that causes a potential difference between the four opposing electrodes 14a and 14b, an electrostatic attractive force is generated between the adjacent electrodes 14a and 14b, and a slight displacement of the electrode 14 causes the diaphragm 10 to move. A large displacement can be obtained, the droplet ejection efficiency is improved, and high image quality recording is possible.

In the microactuator of this head, the sectional shape of the electrode 14 is set to the fixed end portion 14A.
Since the width is smaller than that of the free end portion 14B, the electrode fixing space occupying the surface of the vibration plate 10 (more accurately, the surface of the insulating film 11 in this case) is reduced, and the vibration plate 1 is reduced.
The bendable region of 0 increases, that is, the rigidity of the diaphragm can be suppressed from increasing by providing the electrode 14,
Moreover, the gap where the electrostatic attraction between the electrodes 14, 14 acts can be narrowed, and efficient driving can be performed at a lower voltage.

Further, in the microactuator of this head, the structure itself provided on the diaphragm 10 is the electrode 1
Since it works as 4, there is no need for a difficult step of forming an electrode on a silicon structure by a method such as film formation as in the past, and it is possible to reduce the cost. It is also possible to reduce defects such as a short circuit caused by forming electrodes at narrow intervals. Furthermore, there is no need for a step of separating the electrodes into comb-like shapes after forming the electrodes on the structure, and thus cost reduction and mass production are easy.

Further, the diaphragm 10 and the electrode 14 are made of the insulating film 1.
Since it is electrically separated by 1 or the like, even if a voltage is applied to the electrodes as in the conventional case, all the electrodes are at the same potential via the vibrating plate and malfunction does not occur. The generated voltage does not leak to the diaphragm 10 side, and the voltage can be efficiently applied to the electrode 14. In this case, as an example of electrically separating the vibration plate 10 and the electrode 14, by forming the insulating film 11 between the vibration plate 10 and the electrode 14, it is possible to easily insulate the liquid discharge head with high reliability. Can be obtained. If the diaphragm itself is made of an insulating material, the insulating film may not be provided.

By forming a multilayer film as this insulating film,
As will be described later, a film having a high selectivity in the processing of the electrode material can be used as a base of the electrode material, and the selection range of the process can be widened, and the manufacturing can be performed at low cost and with high reliability.

In this case, by using the silicon oxide film as the insulating film on the electrode side, it is possible to obtain a highly reliable droplet discharge head having a good insulating property and a high breakdown voltage. Also, in the process by anisotropic dry etching when polysilicon is used as the electrode material, the silicon oxide film has a slow etching speed (high selection ratio), so the process margin is widened and a highly reliable droplet discharge head is manufactured. It becomes possible to do.

Next, an ink jet head according to the second embodiment will be described with reference to FIGS. 6 and 7. 6 is a cross-sectional explanatory view of the same head taken along the lateral direction of the diaphragm, and FIG. 7 is an enlarged explanatory view of the electrode portion of the same head. In this embodiment, the electrode 14 is formed in a shape in which the width gradually increases (here, one step) from the fixed end portion 14A side toward the free end portion 14B side.

In addition, the insulating film 11 of the vibration plate 10 has a silicon oxide film 11b on the surface of the high concentration p-type impurity diffusion layer 10a.
And the silicon nitride film 11a are sequentially laminated and formed (in the reverse order of the first embodiment).

By thus forming the cross-sectional shape of the electrode 14 so that the width of the fixed end portion 14A is narrower than that of the free end portion 14B, as described above, the surface of the diaphragm 10 (more precisely, the insulating film 11 in this case). The electrode fixing space occupying the surface) becomes small, and the flexible region of the diaphragm 10 increases, that is,
By providing the electrode 14, it is possible to suppress the rigidity of the diaphragm from increasing, and it is possible to narrow the gap where the electrostatic attractive force acts between the electrodes 14 and 14 to perform efficient driving at a lower voltage. be able to.

Further, by using the silicon nitride film as the insulating film on the electrode side, it is possible to obtain a droplet discharge head having good insulation properties, high breakdown voltage, and high reliability. Further, since the selectivity with respect to the HF aqueous solution is high, a process margin is widened and a highly reliable droplet discharge head can be manufactured.

Therefore, the manufacturing process of the head according to the second embodiment will be described with reference to FIGS. First, as shown in FIG. 8A, a silicon substrate 41 serving as the first substrate 1 having a (110) plane orientation in which a high-concentration boron diffusion layer 10a is formed by doping high-concentration boron to a predetermined depth.
A silicon oxide film 11b and a silicon nitride film 11a are formed thereon to a thickness of 200 nm, and a silicon oxide film 42 serving as a sacrifice layer is formed to a thickness of 2.0 μm on the surface of the silicon nitride film 11a by a CVD method.

Then, as shown in FIG. 7B, the electrode 14 is formed on the silicon oxide film 42, which is a sacrificial layer, by litho etching.
After forming the groove 42a corresponding to the width on the fixed end portion 14A side, a polysilicon 43 as an electrode material is deposited to a thickness of 1.0 μm as shown in FIG. At this time, the groove 4
The inside of 2a is filled with polysilicon 43.

Further, as shown in FIG. 9D, a groove 43a for separating the polysilicon 43 on the silicon oxide film 42 is formed by litho etching.

After that, as shown in FIG. 9A, the silicon oxide film 42 is removed by wet etching using an HF aqueous solution, and as shown in FIG. Direct bonding with silicon substrate). Then, as shown in FIG. 3C, a liquid chamber (discharge chamber) 6 is formed in the silicon substrate 41 by using an anisotropic etching method using KOH. At this time, the high-concentration boron diffusion layer 10a serves as an etch stop layer, and the diaphragm 10 is formed.

By doing so, it is possible to reduce the thickness of the electrode material while keeping the height of the electrode 14 the same as that of the first embodiment, and it is necessary to perform high aspect etching by the dry etching method. Instead, the groove width on the diaphragm 10 side can be widened (the electrode width is narrowed) while keeping the distance between the electrodes that generate the electrostatic force small, so that the rigidity of the diaphragm 10 can be reduced, A head capable of deforming a diaphragm with a lower voltage can be obtained.

The conditions such as the film thickness of various films are not limited to the above examples. Further, the electrode material may be a metal formed by a sputtering method or a high temperature sputtering method, or the electrode may be formed by an electroforming method. Further, only the portions of the electrode portion facing each other through the narrow groove may be formed by the selective CVD method. Furthermore, the insulating film 11 between the first substrate 1 and the electrode 14 is not limited to the two-layer structure of SiN / SiO ₂ , and the number of layers may be a multi-layer structure of three or more layers.

In the above manufacturing process, when removing the sacrificial layer,
HF is used to enable highly selective sacrificial layer etching.
A silicon nitride film having a slow etching speed with respect to an aqueous solution is formed on the electrode side. As a result, the etching time can be sufficiently secured, the sacrifice layer can be surely removed, and defects such as etching residue can be eliminated.

Next, a different example of the ink jet head according to the third embodiment of the present invention will be described with reference to FIGS. Each figure is an enlarged explanatory view of the electrode portion of the same head. In this embodiment, the insulating film 21 is formed on the surface of the electrode 14 of the head of the second embodiment, particularly in the narrow groove portion between the electrodes to further narrow the groove interval for generating an electrostatic force to reduce the effective gap. There is.

That is, for example, a silicon oxide film (with a dielectric constant of about 3.8) is formed on the electrode surface with an electrode interval of 0.5 μm.
When formed with a thickness of 2 μm, the effective gap g is expressed by the following equation (2).

[0063]

[Equation 2]

That is, by forming the insulating film 21,
The gap can be reduced to about 2/5. As described above, the force acting between the electrodes 14 and 14 can be increased as the effective gap is smaller, and the electrostatic force acting between the electrodes 14 and 14 is inversely proportional to the square of the effective gap. Therefore, by forming a thermal oxide film to reduce the execution gap, the force can be increased or the drive voltage can be lowered. There is a limit to the processing of the electrodes to form a narrow gap, and when a groove is formed by dry etching, it is 0.5.
The limit is about μm. By forming an insulating film on the electrode surface, an effective gap smaller than this limit value can be formed and the driving voltage can be lowered.

Further, in order to reduce the driving voltage, it is necessary to reduce the interval between the electrodes 14. However, when the electrodes 14 are formed with such a minute interval, even a small dust will remain on the electrode 14. Will cause a short circuit,
It may cause a malfunction, and since the intervals are very small, even if minute water droplets are generated on the surface of the electrode 14 due to the humidity of the air, it causes a short circuit.

Therefore, by providing the insulating film 21 on the surface of the electrodes 14, the malfunction due to the short circuit between the electrodes 14 can be reduced. Further, discharge may occur between the electrodes 14 when a voltage is applied, which may cause a malfunction. By providing the insulating film 26, the breakdown voltage can be improved, and highly reliable droplet discharge can be achieved. The head is obtained.

Here, the insulating film 21 formed on the surface of the electrode
May be a thermal oxide film or an oxide film formed by a CVD method. The thermal oxide film has good film quality, but it can be formed only when the electrode material is silicon or polysilicon.
Since the film is formed by consuming the electrode material, the effect of reducing the effective gap becomes larger when the insulating film is formed by the CVD method. Furthermore, the effect is further enhanced by using an insulating film having a higher dielectric constant.

The thickness of the insulating film 21 is shown in FIG.
As shown in FIG. 0, the surface of the electrode 14 may have a substantially uniform film thickness, or, as shown in FIG. 11, a non-uniform film thickness that is thin on the fixed end 14A side and thick on the free end 14B side. Can also be By forming a thick film on the free end portion 14B side as in the example shown in FIG.
Vibrating plate 10 that largely acts on the bending moment acting on
The effective gap of the groove portion on the side of the free end portion 14B away from can be reduced, and the diaphragm can be more efficiently deformed.

Next, an ink jet head according to the fourth embodiment of the present invention will be described with reference to FIG. In addition, this figure is an explanatory plan view of an electrode pattern of an electrode portion of the head. In this embodiment, the electrode 14 is formed in a shape in which the width is partially narrowed in the direction in which the electrodes are arranged. That is, the recesses 25 are partially formed in the electrodes 14 to partially widen the groove intervals between the electrodes.

With this structure, when the high aspect etching is performed by dry etching in the head of the first embodiment, etching ions and radicals are easily supplied to the portion to be etched, and the head of the second embodiment is changed. In the head, when the sacrificial layer silicon oxide film is wet-etched, the etching liquid is easily supplied to the portion to be etched.

As a result, the etching time can be shortened, the resist pattern can be thinned, and the process margin can be widened. Further, it is possible to eliminate a short circuit between electrodes due to insufficient etching and an etching residue of the sacrificial layer.

Next, an ink jet head according to the fifth embodiment of the present invention will be described with reference to FIG. In addition, this figure is an explanatory plan view of an electrode pattern of an electrode portion of the head. In this embodiment, the plurality of electrodes 14, 14
The intervals between the electrodes are different from each other in the direction in which the electrodes are arranged. Here, the interval between the plurality of electrodes 14, 14 is narrower in the peripheral portion of the diaphragm 10 than in the central portion of the diaphragm 10, that is, the diaphragm 10.
The distance between the electrodes 14 increases from the peripheral portion toward the center.

With this structure, a large electrostatic force is exerted between the electrodes in the peripheral portion of the diaphragm having a narrower gap than the central portion of the diaphragm, so that the vibration of the entire diaphragm 10 is initially vibrated. The periphery of the plate 10 begins to deform,
As a result, the diaphragm 10 is sequentially deformed from the peripheral portion to the central portion, such as the intermediate portion where the gap becomes narrower, and then the central portion. That is, the vibrating plate 10 operates like a whip, and efficient ink pressurization is possible.

If the gaps between all electrodes are the same,
The same force acts on all the gap portions, but due to the processing variations, the vibration plate randomly operates on the plurality of droplet discharge portions. By configuring as in this embodiment, it is possible to perform stable diaphragm operation in the entire head, and it is possible to perform stable ink droplet ejection.

Next, the ink cartridge according to the present invention will be described with reference to FIG. This ink cartridge 100 is one in which the inkjet head 101 of any of the above-described embodiments having a nozzle hole 101 and the like and an ink tank 102 that supplies ink to the inkjet head 101 are integrated.

As described above, in the case of the head integrated with the ink tank, the cost reduction and reliability of the head immediately lead to the cost reduction and reliability of the entire ink cartridge, so that the cost reduction and the high reliability are achieved as described above. By improving the performance and reducing manufacturing defects, the yield and reliability of the ink cartridge can be improved, and the cost of the head-integrated ink cartridge can be reduced.

Next, an example of an ink jet recording apparatus equipped with the ink jet head or ink cartridge according to the present invention will be described with reference to FIGS. 15 and 16. 15 is a perspective explanatory view of the same recording apparatus, and FIG. 16 is a side view of a mechanical section of the same recording apparatus.

This ink jet recording apparatus has a carriage movable in the main scanning direction inside the recording apparatus main body 111, a recording head including the ink jet head according to the present invention mounted on the carriage, an ink cartridge for supplying ink to the recording head, and the like. Printing mechanism section 11 composed of
A sheet feeding cassette (or a sheet feeding tray) 114 capable of accommodating a large number of sheets 113 from the front side can be detachably attached to the lower portion of the apparatus main body 111 for accommodating 2 or the like. The manual feed tray 115 for manually feeding the paper 113 can be opened and closed, the paper 113 fed from the paper feed cassette 114 or the manual feed tray 115 is taken in, and a desired image is recorded by the printing mechanism unit 112. After that, the output tray 1 mounted on the rear side
The paper is discharged to 16.

The printing mechanism 112 slides the carriage 123 in the main scanning direction (the direction perpendicular to the paper surface in FIG. 16) by the main guide rod 121 and the sub guide rod 122, which are guide members that are horizontally mounted on the left and right side plates (not shown). The carriage 123 is freely held, and yellow (Y), cyan (C),
A head 124, which is an ink jet head that is a droplet ejection head according to the present invention that ejects ink droplets of each color of magenta (M) and black (Bk), is arranged in a direction in which a plurality of ink ejection ports intersects the main scanning direction. , The ink droplet ejection direction is downward. Also, the carriage 123
Each ink cartridge 125 for supplying each color ink to the head 124 is replaceably mounted. The head-integrated ink cartridge according to the present invention can be mounted.

The ink cartridge 125 has an upper atmosphere port communicating with the atmosphere, a lower supply port for supplying ink to the ink jet head, and a porous body filled with ink in the interior. The ink supplied to the inkjet head is maintained at a slight negative pressure by the capillary force of.

Further, although the heads 124 of the respective colors are used here as the recording head, a single head having nozzles for ejecting ink droplets of the respective colors may be used.

Here, the carriage 123 is slidably fitted to the main guide rod 121 on the rear side (downstream side in the sheet conveying direction) and slidably mounted on the sub guide rod 122 on the front side (upstream side in the sheet conveying direction). It is placed in. Then, in order to move and scan the carriage 123 in the main scanning direction, a timing belt 130 is stretched between the drive pulley 128 and the driven pulley 129 which are rotationally driven by the main scanning motor 127, and the timing belt 130 is mounted on the carriage 123. The carriage 123 is reciprocally driven by the forward and reverse rotations of the main scanning motor 127.

On the other hand, in order to convey the paper 113 set in the paper feed cassette 114 to the lower side of the head 124, the paper feed roller 131 and the friction pad 132 for separately feeding the paper 113 from the paper feed cassette 114, and the paper 11 are provided.
Guide member 133 for guiding the sheet 3 and the fed sheet 11
A conveyance roller 134 that reverses and conveys 3 is provided, a conveyance roller 135 that is pressed against the peripheral surface of the conveyance roller 134, and a leading end roller 136 that defines the feed angle of the paper 113 from the conveyance roller 134. Conveyor roller 1
The sub-scanning motor 137 is rotationally driven through a gear train.

Then, a print receiving member 139, which is a paper guide member for guiding the paper 113 sent out from the carrying roller 134 below the recording head 124, corresponding to the movement range of the carriage 123 in the main scanning direction is provided. There is. A transport roller 141 and a spur 142 that are driven to rotate in order to send out the paper 113 in the paper discharge direction are provided on the downstream side of the print receiving member 139 in the paper transport direction, and further, the paper 113 is sent to the paper discharge tray 116. Roller 143 and spur 1
44, and guide members 145 and 146 that form the paper discharge path
And are arranged.

At the time of recording, by driving the recording head 124 in accordance with the image signal while moving the carriage 123, ink is ejected onto the stopped paper 113 to record one line, and the paper 113 is moved by a predetermined amount. After transportation, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the paper 113 reaches the recording area, the recording operation is ended and the paper 113 is ejected. In this case, the head 12
In the ink jet head according to the present invention, which composes No. 4, the controllability of ink droplet ejection is improved and the characteristic variation is suppressed, so that an image with high image quality can be stably recorded.

A recovery device 147 for recovering the ejection failure of the head 124 is arranged at a position outside the recording area on the right end side of the carriage 123 in the moving direction. The recovery device 147 has a cap means, a suction means, and a cleaning means. The carriage 123 is moved to the recovery device 147 side while the printing is on standby, the head 124 is capped by the capping means, and the ejection port portion is kept wet to prevent ejection failure due to ink drying.
Also, by ejecting ink that is not related to recording during recording, etc., the ink viscosity of all ejection ports is made constant,
Maintains stable discharge performance.

When a discharge failure occurs, the discharge port (nozzle) of the head 124 is sealed by capping means,
Bubbles and the like are sucked out together with the ink from the discharge port by the suction means through the tube, and the ink and dust adhering to the surface of the discharge port are removed by the cleaning means to recover the discharge failure. Further, the sucked ink is discharged to a waste ink reservoir (not shown) installed in the lower portion of the main body, and is absorbed and held by an ink absorber inside the waste ink reservoir.

As described above, in this ink jet recording apparatus, since the ink jet head or the ink cartridge embodying the present invention is mounted, there is no ink droplet ejection failure due to defective driving of the diaphragm, and stable ink droplet ejection characteristics are obtained. As a result, the image quality is improved. Further, since a head that can be driven at a low voltage is mounted, the power consumption of the entire inkjet recording device can be reduced.

Next, the micropump according to the present invention will be described with reference to FIG. It should be noted that the figure is a cross-sectional explanatory view of the main parts of the micropump. This micropump has a laminated structure in which a flow path substrate 201 and a protective substrate 202 are overlapped and bonded to each other. A flow path 203 through which a fluid flows is formed in the flow path substrate 201, and one wall surface of the flow path 203 is formed. A deformable movable plate 204 (corresponding to a vibration plate of the head) to be formed is provided, and the protective substrate 202 of the movable plate 204 is provided.
The portion that is not joined and fixed with is a movable portion 205.

An insulating film 206 is formed on the movable portion 205.
A plurality of electrodes 207 (having the same configuration as the electrodes 14 of the head according to the second embodiment) are provided on the outer surface side through the vias with a predetermined space therebetween. The protective substrate 202 is the second substrate 2 of the head.
It has a function similar to that of the above, and forms a recess 208 for disposing the electrode 207. Here, the protective substrate 202 has the concave portion 208 formed by providing the spacer portion 209 on the flat plate substrate.

Explaining the operating principle of this micropump, as described above, the electrostatic attraction force is generated between the electrodes 207 by applying the pulse potential to the plurality of electrodes 207 every other one. It deforms to the flow path 203 side. Here, by sequentially driving the movable part 205 from the right side in the drawing, the fluid in the flow path 203 flows in the direction of the arrow, and the fluid can be transported.

In this embodiment, the example in which a plurality of movable parts are provided is shown, but the number of movable parts may be one. Also, one or more valves between moving parts to increase transport efficiency,
For example, a check valve may be provided.

Next, an embodiment of the optical device according to the present invention will be described with reference to FIG. The figure is a schematic configuration diagram of the device. In this optical device, a deformable mirror 301 and a protective substrate 302 are overlapped and bonded to each other, and a portion of the mirror 301 which is not bonded and fixed to the protective substrate 302 is a movable part 305. A plurality of electrodes 307 (having the same structure as the electrode 14 of the head of the second embodiment) are provided on the outer surface side of the movable portion 305 via the insulating film 306 at predetermined intervals. The protective substrate 302 has a function similar to that of the second substrate 2 of the head, and the concave portion 30 for disposing the electrode 307.
8 forming. Here, the protective substrate 302 has a recess 308 formed by providing a spacer portion 309 on a flat plate substrate. A dielectric multilayer film or a metal film may be formed on the surface of the mirror 301 to increase the reflectance.

The principle of this optical device will be described. A plurality of electrodes 307 provided on the movable portion 305 of the mirror 301.
To every other pulse potential,
Since an electrostatic attraction force is generated between the electrodes 307, the movable part 30
5 is transformed into a convex shape to form a convex mirror. Therefore, the light from the light source 310 passes through the lens 311 and the mirror 301.
When the mirror 301 is not driven,
The light is reflected at the same angle as the incident angle, but when the movable portion 305 is driven by the mirror 301, the movable portion 305 serves as a convex mirror, so that the reflected light becomes divergent light. Thereby, an optical modulation device can be realized.

Therefore, an example in which this optical device is applied will be described with reference to FIGS. 19 and 20. In this example, the above-mentioned optical devices are two-dimensionally arranged and the movable portion 305 of each mirror is independently driven.
Although a 4 × 4 array is shown here, more arrays are possible. The electrodes 307 are separated in a grid pattern on the surface of the movable portion 305 (the electrode 14 can be separated in a grid pattern in the same manner as the electrode 305 in the embodiment of the droplet discharge head). .

Therefore, as in the case of FIG. 18, the light from the light source 310 passes through the lens 311 and the mirror 301.
The light that is applied to the area where the mirror 301 is not driven enters the projection lens 312. On the other hand, a voltage is applied to the electrode 307 to move the movable portion 30 of the mirror 301.
Since the portion where 5 is deformed is a convex mirror, light diverges and hardly enters the projection lens 312. The light incident on the projection lens 312 is projected on a screen (not shown) or the like, and an image can be displayed on the screen.

In the embodiments of these micropumps and optical devices, the actuator having the same structure as the ink jet head according to the second embodiment is used, but with the ink jet heads according to the first and third embodiments and thereafter. An actuator having a similar structure can be used.

In the above embodiment, an example in which the liquid droplet ejection head is applied to an ink jet head has been described. However, as a liquid droplet ejection head other than the ink jet head, for example, a liquid droplet ejection for ejecting liquid resist as a liquid droplet. The present invention can also be applied to other droplet discharge heads such as a head and a droplet discharge head that discharges a DNA sample as droplets. The microactuator can be applied not only to micropumps and optical devices (light modulation devices) but also to microswitches (microrelays), multi-optical lens actuators (optical switches), microflowmeters, pressure sensors, etc. it can. Further, although the example in which the electrodes are provided on one side of the diaphragm has been described, the electrodes may be provided on both sides.

[0099]

As described above, according to the droplet discharge head of the present invention, the vibrating plate is made of a conductive structure that is electrically insulated and separated from each other, and the fixed end is the free end. Since a plurality of electrodes having a width narrower than that of the side are provided and the vibrating plate is deformed by generating an electrostatic force between the electrodes, it is possible to obtain a head capable of high-quality printing at low cost with high droplet ejection efficiency. In addition, the electrode interval can be narrowed while suppressing the rigidity of the diaphragm from increasing, and low voltage driving can be achieved.

Here, since the width of the electrode changes continuously or stepwise, it is possible to prevent the electrode space on the diaphragm side from being reduced and the rigidity of the diaphragm to be increased, and the free end portion to be suppressed. The electrode spacing on the side can be narrowed, and low voltage driving can be achieved.

Further, since the electrodes are made of polysilicon, uniform and low-resistance electrodes can be easily formed.
A highly reliable head with less variation can be obtained at low cost.

Furthermore, by forming an insulating film on the surface of the electrodes, the effective gap between the electrodes can be reduced,
In addition to being able to drive at a lower voltage, malfunctions due to electrode shorts can be reduced, and the breakdown voltage is also improved.
Improves reliability. In this case, the insulating film on the electrode surface can be easily formed by making the film thickness substantially uniform, and by making the film thickness on the fixed end side smaller than the film thickness on the free end side, the vibration plate can be formed. An increase in the electrode space on the side can be suppressed, and efficient driving can be performed.

Further, the insulating film is a SiO ₂ film, Si ₃ N
₄ film, SiON film, or SiOF film, which is commonly used in semiconductor manufacturing.
It is possible to form a uniform and stable film by forming a film by the method, and it is also possible to form a stable film by forming a film by the plasma CVD method which is also commonly used in semiconductor manufacturing. It is possible to manufacture a stable head at low cost.

Further, since the insulating film is formed between the diaphragm and the electrode, even if the diaphragm is conductive, the voltage applied to the electrode does not leak to the diaphragm side and the driving can be performed. Therefore, the voltage can be efficiently applied to the electrodes. By making this insulating film a multilayer film, the material selectivity in the processing of the electrode material becomes high, and a film with a high etching selectivity can be used as the base material for the electrode material, which widens the selection range of the process and is inexpensive. It is possible to manufacture a highly reliable head.

In this case, since at least the electrode-side film of the multilayer film is made of a silicon oxide film, the silicon oxide film has a good insulating property and a high withstand voltage, so that the reliability is improved and the electrode material is made of polysilicon. In the processing by anisotropic dry etching when using, the silicon oxide film has a slow etching speed (high selection ratio), so that a process margin is widened and a highly reliable head can be manufactured. In addition, since at least the electrode side film of the multilayer film is a silicon nitride film, the silicon nitride film also has good insulation and high withstand voltage, so that the reliability is improved, and the sacrifice in the manufacturing method according to the present invention is improved. Since the selectivity is high with respect to the HF aqueous solution used for layer removal, the process margin is widened and a highly reliable head can be manufactured.

Furthermore, since the electrodes are partially narrowed in the direction in which the electrodes are arranged, it is possible to eliminate short-circuiting between the electrodes and etching residue of the sacrificial layer due to insufficient etching, thereby improving the yield. It is possible to manufacture a highly reliable head.

Further, since the intervals between the plurality of electrodes are different depending on the direction in which the electrodes are arranged, the operation of the diaphragm can be controlled to be constant regardless of processing variations, and efficient driving can be performed. In this case, since the vibrating plate peripheral portion is narrower than the vibrating plate central portion in the interval between the plurality of electrodes, the vibrating plate can be deformed from the vibrating plate peripheral portion toward the central portion, and thus can be efficiently deformed.

Furthermore, by forming part of the electrodes by the selective CVD method or electroforming, low resistance electrodes can be uniformly formed at low cost, and the cost of the head can be reduced.

According to the method of manufacturing a droplet discharge head according to the present invention, the method of manufacturing a droplet discharge head according to the present invention in which the width of the electrodes is continuously changed, wherein the electrodes are between the electrodes. Since the groove is formed by anisotropic etching, it is possible to form an electrode having a variable width at low cost.

According to the method of manufacturing a droplet discharge head of the present invention, a method of manufacturing a droplet discharge head in which the width of an electrode changes stepwise, wherein the electrode is a sacrificial layer in a narrow portion. After anisotropic etching of the groove between the electrodes corresponding to the wide portion with the provision, the sacrifice layer of the narrow portion is removed by wet etching, so that high aspect etching is not required. The electrodes can be formed, and it is possible to prevent a reduction in yield such as a short circuit caused by a processing defect having a narrow electrode interval.

In this case, by using a silicon oxide film for the sacrificial layer, the uniformity in the wafer surface is good, and a uniform electrode shape can be formed. Further, even when the sacrifice layer is removed, it is possible to easily reduce the electrode shape by wet etching. Can be removed at cost. Especially, the silicon oxide film is plasma C
The cost can be reduced by forming the film by the VD method.

According to the ink cartridge of the present invention, since the droplet discharge head according to the present invention for discharging ink droplets and the ink tank for supplying ink to the droplet discharge head are integrated, manufacturing defects are reduced. The cost can be reduced.

According to the ink jet recording apparatus of the present invention, since the liquid droplet ejection head or the ink cartridge of the present invention is mounted as an ink jet head for ejecting ink droplets, the cost of the apparatus can be reduced.

The microactuator according to the present invention is a microactuator for deforming a movable part, which is composed of a conductive structure electrically insulated and separated from each other in the movable part, and the fixed end is a free end. Since a plurality of electrodes having a width narrower than that of the part side are provided and the movable part is deformed by generating an electrostatic force between the electrodes, an actuator with high operation efficiency can be obtained at low cost, and moreover,
The electrode spacing can be narrowed while suppressing the increase in the rigidity of the diaphragm, and low voltage driving can be achieved.

According to the micropump of the present invention, which is a micropump that transports a liquid by deformation of a movable part, and is equipped with the microactuator of the present invention, it is possible to achieve a small size and low power consumption. The cost can be reduced.

According to the optical device of the present invention, the optical device changes the reflection direction of light by the displacement of the mirror formed in the movable part, and is equipped with the microactuator of the present invention. It is possible to reduce power consumption and cost.

[Brief description of drawings]

FIG. 1 is an exploded perspective view illustrating an inkjet head according to a first embodiment of a droplet discharge head of the invention.

FIG. 2 is a cross-sectional explanatory view of the same head in the diaphragm longitudinal direction.

FIG. 3 is an enlarged cross-sectional explanatory view of a main part of the head in a lateral direction of a diaphragm.

FIG. 4 is an explanatory plan view for explaining an electrode arrangement pattern of the head.

FIG. 5 is an enlarged cross-sectional explanatory view of an essential part for explaining the operation of the head.

FIG. 6 is an explanatory cross-sectional view of a main part of the inkjet head according to the second embodiment, taken along the lateral direction of the diaphragm.

FIG. 7 is an enlarged explanatory diagram of an electrode portion of the head.

FIG. 8 is an explanatory diagram illustrating an example of a manufacturing process of the head.

FIG. 9 is an explanatory diagram illustrating a step following FIG.

FIG. 10 is an enlarged explanatory view of an electrode portion for explaining an example of the inkjet head according to the third embodiment.

FIG. 11 is an enlarged explanatory view of an electrode portion for explaining another example of the inkjet head according to the embodiment.

FIG. 12 is an explanatory plan view of an electrode pattern for explaining an example of the inkjet head according to the fourth embodiment.

FIG. 13 is an explanatory plan view of an electrode pattern for explaining an example of the inkjet head according to the fifth embodiment.

FIG. 14 is a perspective explanatory view for explaining an ink cartridge according to the present invention.

FIG. 15 is a perspective explanatory view illustrating an example of an inkjet recording apparatus according to the present invention.

FIG. 16 is an explanatory diagram of a mechanical section of the recording apparatus.

FIG. 17 is a cross-sectional explanatory diagram illustrating an embodiment of a micropump according to the present invention.

FIG. 18 is a sectional explanatory view illustrating an embodiment of an optical device according to the present invention.

FIG. 19 is a perspective explanatory view illustrating an example of a light modulation device using the optical device.

FIG. 20 is a perspective view for explaining a main part of the optical modulation device.

[Explanation of symbols]

1 ... 1st substrate, 2 ... 2nd substrate, 3 ... Nozzle plate, 4 ... Nozzle hole, 6 ... Discharge chamber, 7 ... Fluid resistance part, 8 ... Common liquid chamber, 1
0 ... Vibration plate, 14 ... Electrode, 21 ... Insulating film, 100 ... Ink cartridge, 201 ... Flow path substrate, 203 ... Flow path, 2
05 ... Movable part, 207 ... Electrode, 301 ... Mirror, 30
5 ... Movable part, 307 ... Electrode.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 41/09 H01L 41/22 Z 41/22 (72) Inventor Koji Onishi 1-chome, Nakamagome, Ota-ku, Tokyo No. 3-6 Inside Ricoh Company (72) Inventor Kunihiro Yamanaka 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Kenichiro Hashimoto 1-3-6 Nakamagome, Ota-ku, Tokyo In stock company Ricoh (72) Inventor Makoto Tanaka 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh stock company (72) Inventor Tadashi Mimura 1-3-6 Nakamagome, Tokyo Ota-ku Ricoh company F-term (reference) 2C056 EA24 FA02 HA16 HA17 KC01 2C057 AF51 AF93 AG54 AG56 AG70 AP34 AP38 AP53 BA04 BA14 BA15

Claims (25)

[Claims] 1. A vibrating plate, comprising: a single or a plurality of nozzle holes for ejecting droplets; a discharge chamber communicating with each of the nozzle holes; and a vibration plate constituting at least one wall of the discharge chamber. In a droplet discharge head that applies pressure to a liquid to discharge droplets by deforming a plate, the vibrating plate is formed of a conductive structure that is electrically insulated and separated from each other, and a fixed end portion is a free end portion. A droplet discharge head characterized in that a plurality of electrodes having a width narrower than that of the side are provided, and the vibrating plate is deformed by generating an electrostatic force between the electrodes. 2. The droplet discharge head according to claim 1, wherein the width of the electrode is continuously changed. 3. The droplet discharge head according to claim 1, wherein the width of the electrode is changed stepwise. 4. The droplet discharge head according to claim 1, wherein the electrode is made of polysilicon. 5. The droplet discharge head according to claim 1, wherein an insulating film is formed on the surface of the electrode. 6. The droplet discharge head according to claim 5, wherein the insulating film on the surface of the electrode has a substantially uniform film thickness. 7. The droplet discharge head according to claim 5, wherein the insulating film on the electrode surface has a film thickness on the fixed end side smaller than that on the free end side. . 8. The droplet discharge head according to claim 5, wherein the insulating film is a SiO ₂ film or a Si ₃ film.
A droplet discharge head, which is one of an N ₄ film, a SiON film, and a SiOF film. 9. The droplet discharge head according to claim 1, wherein an insulating film is formed between the vibrating plate and the electrode. 10. The droplet discharge head according to claim 9, wherein the insulating film is a multilayer film. 11. The droplet discharge head according to claim 10, wherein at least an electrode side film of the multilayer film is a silicon oxide film or a silicon nitride film. 12. The droplet discharge head according to claim 1, wherein the electrode has a partially narrowed width in a direction in which the electrodes are arranged. 13. The droplet discharge head according to claim 1, wherein the plurality of electrodes have different intervals in the arrangement direction of the electrodes. 14. The droplet discharge head according to claim 13, wherein a distance between the plurality of electrodes is smaller in a peripheral portion of the diaphragm than in a central portion of the diaphragm. 15. The droplet discharge head according to claim 1, wherein a part of the electrode is formed by a selective CVD method. 16. The droplet discharge head according to claim 1, wherein the electrodes are formed by electroforming. 17. The method of manufacturing a droplet discharge head according to claim 2, wherein the electrode is formed by anisotropically etching a groove between the electrodes. Method. 18. The method of manufacturing a droplet discharge head according to claim 3, wherein the electrodes have a groove between the electrodes corresponding to the wide portion in a state where the sacrificial layer is provided in the narrow portion. A method of manufacturing a droplet discharge head, characterized in that the sacrifice layer in a narrow portion is removed by wet etching after anisotropic etching. 19. The method of manufacturing a droplet discharge head according to claim 16, wherein the sacrificial layer is a silicon oxide film. 20. The method of manufacturing a droplet discharge head according to claim 19, wherein the silicon oxide film is plasma CV.
A method of manufacturing a droplet discharge head, characterized in that a film is formed by the D method. 21. An ink cartridge in which a droplet discharge head that discharges an ink droplet and an ink tank that supplies ink to the droplet discharge head are integrated, wherein the droplet discharge head is any one of claims 1 to 16. An ink cartridge, which is the above-mentioned droplet discharge head. 22. In an inkjet recording apparatus equipped with an inkjet head for ejecting ink droplets, the inkjet head is the droplet ejection head according to any one of claims 1 to 16 or the ink cartridge according to claim 21. An ink jet recording apparatus characterized by the above. 23. A microactuator for deforming a movable part, wherein the movable part is composed of a conductive structure that is electrically insulated and separated from each other, and a fixed end portion is narrower than a free end portion side. A microactuator comprising a plurality of electrodes, wherein the movable portion is deformed by generating an electrostatic force between the electrodes. 24. A micropump for transporting a liquid by deformation of a movable part, comprising the microactuator according to claim 23. 25. An optical device for changing the reflection direction of light by displacing a mirror formed on a movable part,
An optical device comprising the microactuator according to claim 23.