JP3114808B2 - Ink jet recording head and ink jet recording apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure generating chamber which communicates with a nozzle opening for discharging ink droplets, which is constituted by a vibrating plate, and a piezoelectric element is provided through the vibrating plate to displace the piezoelectric element. TECHNICAL FIELD The present invention relates to an ink jet recording head and an ink jet recording apparatus for ejecting ink droplets by means of a printer.

[0002]

2. Description of the Related Art A part of a pressure generating chamber communicating with a nozzle opening for discharging ink droplets is constituted by a vibrating plate, and the vibrating plate is deformed by a piezoelectric element to pressurize the ink in the pressure generating chamber to pass the nozzle opening. Two types of ink jet recording heads that eject ink droplets have been commercialized, one using a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element, and the other using a flexural vibration mode piezoelectric actuator. ing.

[0003] In the former, the volume of the pressure generating chamber can be changed by bringing the end face of the piezoelectric element into contact with the diaphragm, and a head suitable for high-density printing can be manufactured. There is a problem in that a difficult process of cutting into a comb shape in accordance with the arrangement pitch of the openings and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are required, and the manufacturing process is complicated.

On the other hand, in the latter, a piezoelectric element can be formed on a diaphragm by a relatively simple process of sticking a green sheet of a piezoelectric material according to the shape of a pressure generating chamber and firing the green sheet. In addition, there is a problem that a certain area is required due to the use of flexural vibration, and that high-density arrangement is difficult.

On the other hand, in order to solve the latter disadvantage of the recording head, a uniform piezoelectric material layer is formed by a film forming technique over the entire surface of the diaphragm as disclosed in Japanese Patent Application Laid-Open No. 5-286131. A proposal has been made in which the piezoelectric material layer is cut into a shape corresponding to the pressure generating chambers by a lithography method, and a piezoelectric element is formed so as to be independent for each pressure generating chamber.

[0006] According to this, the operation of attaching the piezoelectric element to the diaphragm becomes unnecessary, and not only can the piezoelectric element be manufactured by a precise and simple method such as lithography, but also the thickness of the piezoelectric element can be reduced. There is an advantage that it can be made thin and can be driven at high speed.

Further, in this case, the piezoelectric element corresponding to each pressure generating chamber can be driven by providing at least only the upper electrode for each pressure generating chamber while the piezoelectric material layer is provided on the entire surface of the vibration plate. However, due to the problem of the amount of displacement per unit drive voltage and the stress applied to the piezoelectric layer at the part facing the pressure generating chamber and the part straddling the outside, the piezoelectric active part consisting of the piezoelectric layer and the upper electrode is pressurized. It is desirable to form so as not to go out of the generation chamber.

Therefore, the piezoelectric element corresponding to each pressure generating chamber is covered with an insulating layer, and a window (hereinafter, referred to as a window) for forming a connection portion with a lead electrode for supplying a voltage for driving each piezoelectric element to the insulating layer. , A contact hole) is provided corresponding to each pressure generating chamber, and a connection portion between each piezoelectric element and a lead electrode is formed in the contact hole.

[0009]

However, in a structure in which a contact hole is provided for connecting the upper electrode and the lead electrode, the entire thickness of the portion where the contact hole is provided becomes large, and the displacement characteristics are reduced. Problem.

In the above-described ink jet recording head, a structure has been proposed in which the diaphragms at portions corresponding to both sides of the piezoelectric element are made thin in order to improve the displacement efficiency by driving the piezoelectric element. If the displacement is made large in this way, the tendency of breakage such as cracks to occur particularly near the contact hole is promoted.

Further, these problems tend to occur particularly when the piezoelectric material layer is formed by a film forming technique. Because
This is because the rigidity of the piezoelectric material layer formed by the film formation technique is lower than that of a piezoelectric material layer attached thereto because the piezoelectric material layer is extremely thin.

In view of such circumstances, it is an object of the present invention to provide an ink jet type recording head and an ink jet type recording apparatus which prevent breakage of a piezoelectric layer at a boundary between a pressure generating chamber and a peripheral wall. .

[0013]

According to a first aspect of the present invention, there is provided a pressure generating chamber communicating with a nozzle opening, and a pressure generating chamber provided in a region corresponding to the pressure generating chamber via an insulating layer. In an ink jet recording head including a lower electrode, a piezoelectric layer provided on the lower electrode, and a piezoelectric element including an upper electrode provided on the surface of the piezoelectric layer, the piezoelectric element is disposed in the pressure generating chamber. Substantially in opposing areas
And a continuous piezoelectric active part
Having said piezoelectric layer but substantially not driven
The inkjet recording head has a body non-active portion, and the piezoelectric layer has crystals preferentially oriented.

In the first aspect, the piezoelectric layer is formed of a thin film
As a result, the crystal is preferentially oriented , and the displacement at the boundary between the pressure generating chamber and the peripheral wall is suppressed by the piezoelectric inactive portion when the piezoelectric active portion is driven. Peeling,
Cracks are prevented from occurring.

[0015]

[0016]

According to a second aspect of the present invention, there is provided the ink jet recording head according to the first aspect, wherein the piezoelectric layer has a columnar crystal.

In the second aspect, as a result of the piezoelectric layer being formed in the thin film process, the crystals are columnar.

According to a third aspect of the present invention, in the first or second aspect, the piezoelectric inactive portion extends from an area facing the pressure generating chamber to an area outside the pressure generating chamber. In the ink jet recording head.

In the third aspect, the upper electrode or the lead electrode of the piezoelectric active portion can be extended to the outside of the region facing the pressure generating chamber without forming a contact hole, so that the wiring can be relatively easily performed. Can be formed.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the piezoelectric inactive portion is formed by removing the lower electrode, and the piezoelectric inactive portion is formed through the piezoelectric inactive portion. An ink jet recording head is characterized in that an upper electrode or a lead electrode connected to the upper electrode is extended to a peripheral wall of the pressure generating chamber.

According to the fourth aspect, the upper electrode or the lead electrode of the piezoelectric active portion can be extended to the outside of the region facing the pressure generating chamber without forming a contact hole, and the displacement of the diaphragm can be reduced. Can be improved.

According to a fifth aspect of the present invention, in any one of the first to third aspects, the end of the upper electrode is located inside the end of the lower electrode, and And the piezoelectric layer is provided on the lower electrode protruding outward from the end of the upper electrode to constitute the piezoelectric non-active portion and to the outside of the end of the lower electrode. The present invention also provides an ink jet recording head, wherein the piezoelectric layer is provided.

In the fifth aspect, the distance between the end of the piezoelectric active portion and the end of the lower electrode can be increased, and dielectric breakdown due to electric field concentration at the longitudinal end of the piezoelectric active portion can be prevented. Is done.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the piezoelectric inactive portion is provided continuously at one longitudinal end of the piezoelectric active portion. An ink jet recording head is characterized in that:

According to the sixth aspect, peeling, cracking, and the like at the longitudinal end of the piezoelectric active portion are prevented.

According to a seventh aspect of the present invention, in the sixth aspect, the width of at least a portion of the non-active portion of the piezoelectric body which crosses the boundary between the end of the pressure generating chamber and the peripheral wall is set to the width of the piezoelectric active portion. An ink jet recording head characterized in that the width is smaller than the width of the portion.

In the seventh aspect, the displacement characteristics in the region facing the boundary between the pressure generating chamber and the peripheral wall are improved.

According to an eighth aspect of the present invention, in the sixth aspect, the width of at least a portion of the piezoelectric inactive portion near a boundary between an end of the pressure generation chamber and a peripheral wall is set to be smaller than the pressure generation chamber. Ink jet recording heads characterized by being wider than the width of the ink jet recording head.

In the eighth aspect, the rigidity of the vibrating plate near the end of the pressure generating chamber is kept high, and the vibrating plate is prevented from being broken by driving the piezoelectric active unit.

According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the piezoelectric active portion is provided in a region facing a boundary between the piezoelectric active portion and the piezoelectric inactive portion. An ink jet recording head is provided with a displacement suppressing layer for suppressing displacement of the recording head.

In the ninth aspect, the displacement at the end of the piezoelectric active portion is suppressed, and the diaphragm is prevented from being broken by driving the piezoelectric active portion.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the lower electrode extends to the partition on both sides in the width direction of the pressure generating chamber and a region facing the adjacent pressure generating chamber. An ink jet recording head is provided continuously.

In the tenth aspect, the rigidity of the diaphragm at both ends in the width direction of the pressure generating chamber is maintained high, and the durability of the diaphragm is improved.

According to an eleventh aspect of the present invention, in any one of the first to ninth aspects, both ends in the width direction of the lower electrode are located in the pressure generating chamber together with both ends in the width direction of the piezoelectric layer. And the other end of the piezoelectric body non-active portion is opposite to the one end in the longitudinal direction and extends from the other end to the peripheral wall of the pressure generating chamber. In the head.

In the eleventh aspect, the distance between the end of the piezoelectric active part and the end of the lower electrode can be increased, and dielectric breakdown due to electric field concentration at the longitudinal end of the piezoelectric active part can be prevented. Is done.

According to a twelfth aspect of the present invention, in any one of the first to tenth aspects, a region facing the pressure generating chamber other than the piezoelectric inactive portion is covered by the lower electrode. The feature is the ink jet recording head.

In the twelfth aspect, since there is no end of the lower electrode around the upper electrode patterned in the pressure generating chamber, discharge does not easily occur, and dielectric breakdown of the piezoelectric layer is prevented.

According to a thirteenth aspect of the present invention, in any one of the third to twelfth aspects, the width of the lower electrode below the piezoelectric inactive portion is removed from the width of the pressure generating chamber. Is also narrow in the ink jet recording head.

In the thirteenth aspect, dielectric breakdown of the piezoelectric layer is prevented without reducing the rigidity near the end of the pressure generating chamber.

According to a fourteenth aspect of the present invention, in the twelfth aspect, the piezoelectric inactive portion is provided on at least one peripheral wall in a width direction of the pressure generating chamber from a substantially central portion in a longitudinal direction of the pressure generating chamber. The ink jet type recording head is characterized by being extended.

In the fourteenth aspect, a voltage can be applied to the central portion in the longitudinal direction of the piezoelectric active portion, and the driving loss of the piezoelectric active portion can be suppressed.

According to a fifteenth aspect of the present invention, in any one of the twelfth to fourteenth aspects, the portion from which the lower electrode is removed under the piezoelectric inactive portion has a substantially circular shape. The feature is the ink jet recording head.

In the fifteenth aspect, the electric field applied between the upper electrode and the lower electrode at the boundary between the end of the pressure generating chamber and the peripheral wall is more widely dispersed, and dielectric breakdown of the piezoelectric layer is prevented. You.

According to a sixteenth aspect of the present invention, in any one of the twelfth to fifteenth aspects, the direction in which the edge of the upper electrode crosses from above the lower electrode to above the lower electrode removing portion, and Are inconsistent with the direction in which they extend on the peripheral wall.

In the sixteenth aspect, the electric field applied between the upper electrode and the lower electrode at the boundary between the end of the pressure generating chamber and the peripheral wall is reliably dispersed, and the dielectric breakdown of the piezoelectric layer is reliably prevented. Is prevented.

According to a seventeenth aspect of the present invention, in any one of the first to sixteenth aspects, the width of the lower electrode in a portion facing the vicinity of the end of the piezoelectric active portion on the side of the piezoelectric inactive portion is provided. However, in the ink jet recording head, the width is narrower than the width of other portions.

In the seventeenth aspect, dielectric breakdown between the electrodes is prevented at a portion where the piezoelectric layer and the upper electrode extend from the region of the pressure generating chamber to the outside of the region.

According to an eighteenth aspect of the present invention, in the seventeenth aspect, the width of at least the tip of the narrow portion of the lower electrode is smaller than the width of the piezoelectric layer and the upper electrode of the piezoelectric non-active portion. An ink jet recording head is characterized in that:

In the eighteenth aspect, at least the distal end of the narrow portion is covered with the piezoelectric layer, and is reliably insulated from the upper electrode.

According to a nineteenth aspect of the present invention, in the seventeenth aspect, the entire width of the narrow portion of the lower electrode is smaller than the piezoelectric layer and the upper electrode of the piezoelectric non-active portion. Ink-jet recording head.

In the nineteenth aspect, the entire narrow portion is covered with the piezoelectric layer, and the narrow portion of the lower electrode is reliably insulated from the upper electrode.

According to a twentieth aspect of the present invention, in the seventeenth aspect, the width of the narrow portion of the lower electrode is wider than the width of the piezoelectric layer and the upper electrode of the piezoelectric inactive portion, and The distance between the width direction end face of the narrow portion and the width direction end face of the upper electrode is 10
μm or less .

In the twentieth aspect, by setting the distance between the lower electrode and the upper electrode within a predetermined distance, discharge between the two electrodes is prevented.

According to a twenty-first aspect of the present invention, in any one of the third to twentieth aspects, the lower part of the piezoelectric layer is provided below the piezoelectric layer in a region opposed to a boundary between the pressure generating chamber and the peripheral wall. The electrode is provided with a discontinuous lower electrode that is discontinuous, and is provided in an ink jet recording head.

In the twenty-first aspect, the rigidity of the diaphragm at the portion where the piezoelectric layer and the upper electrode are drawn out to the region outside the pressure generating chamber is maintained high, and the diaphragm and the piezoelectric layer at this portion are prevented from being broken. Is done.

According to a twenty-second aspect of the present invention, in the ink-jet recording head according to the twenty-first aspect, the discontinuous lower electrode is provided so as to cover at least an edge of the pressure generating chamber. is there.

In the twenty-second aspect, the rigidity of the diaphragm near the end of the pressure generating chamber is reliably maintained high, and the durability is improved.

According to a twenty-third aspect of the present invention, a twenty-first or a twenty-second aspect is provided.
In the aspect, the discontinuous lower electrode is provided near the longitudinal end of the pressure generating chamber of the lower electrode, and is connected to the lower electrode by a lower electrode removing portion extending in the direction in which the pressure generating chambers are juxtaposed. An ink jet recording head characterized by being continuous.

In the twenty-third aspect, the distance between the discontinuous lower electrode and the lower electrode can be reduced, and the rigidity of the diaphragm is kept higher.

According to a twenty-fourth aspect of the present invention, in the ink-jet recording head according to any one of the twenty-first to twenty- third aspects, the discontinuous lower electrode is not electrically connected to any of them. is there.

In the twenty-fourth aspect, the discontinuous lower electrode and the lower electrode are reliably insulated.

According to a twenty-fifth aspect of the present invention, in any one of the twenty-first to twenty- third aspects, the discontinuous lower electrode is connected to a resistor such that a charging time constant is larger than a driving pulse. An ink jet recording head is characterized in that:

In the twenty-fifth aspect, the discontinuous lower electrode is reliably insulated from the lower electrode, and the discontinuous lower electrode is prevented from having an excessive potential.

According to a twenty-sixth aspect of the present invention, in any one of the twenty-first to twenty- fifth aspects, the discontinuous lower electrode is connected to the discontinuous lower electrode on the peripheral wall of the opposite side to the lower electrode. An ink jet recording head is characterized in that a wiring lower electrode that is continuous and one end of which is connected to an external wiring is provided for each of the piezoelectric elements.

In the twenty-sixth aspect, the wiring can be easily and efficiently extracted from the piezoelectric active portion.

According to a twenty-seventh aspect of the present invention, in any one of the twenty-first to twenty- third aspects, the discontinuous lower electrode is separated for each of the piezoelectric active portions in a width direction of the pressure generating chamber. And a lead electrode connected to the upper electrode of each of the piezoelectric active portions or a lead electrode connected to the upper electrode.

In the twenty-seventh aspect, the rigidity of the diaphragm at the portion where the piezoelectric layer and the upper electrode are drawn out of the region outside the pressure generating chamber is kept high, and the wiring can be efficiently drawn out.

According to a twenty-eighth aspect of the present invention, in the ink-jet recording head according to the twenty-seventh aspect, each of the discontinuous lower electrodes and the lower electrodes has an interval capable of insulating each other. .

In the twenty-eighth aspect, each of the piezoelectric active portions is reliably driven, and the ejection characteristics are well maintained.

The twenty-ninth aspect of the present invention is directed to a twenty-seventh or a twenty-eighth aspect.
In the aspect, between the adjacent discontinuous lower electrodes,
An ink jet recording head having an intermediate electrode not connected to any of them.

In the twenty-ninth aspect, the removal of the lower electrode film can be minimized, and the rigidity of the diaphragm can be maintained more reliably.

According to a thirtieth aspect of the present invention, in any one of the twenty-first to twenty-ninth aspects, the piezoelectric layer remains in at least a part of the lower electrode film removed portion other than a region corresponding to the piezoelectric element. An ink jet recording head is characterized in that:

In the thirtieth aspect, the discontinuous portion and the lower electrode are reliably insulated, and the reliability can be improved.

[0075] 31 embodiment of the present invention, in the 1 to 30 any of the aspects of, in the pressure generating chamber on both sides in the width direction of the partition wall is the residual portion composed of the same layer as the lower electrode An ink jet recording head is provided.

In the thirty-first aspect, since the area for removing the lower electrode is reduced, the piezoelectric layer is formed with a substantially uniform film thickness on the patterned lower electrode.

According to a thirty-second aspect of the present invention, in the thirty- first aspect, a discontinuous lower electrode that is discontinuous to the lower electrode is provided outside an end of the lower electrode of the piezoelectric active portion. ,
In the ink jet type recording head, the residual portion continuously extends from the discontinuous lower electrode.

In the thirty-second aspect, the distance between the lower electrode constituting the piezoelectric element and the remaining portion can be reduced, and the piezoelectric layer is more reliably formed with a uniform film thickness.

A thirty-third aspect of the present invention is the ink jet recording head according to the thirty-first aspect, wherein the residual portion is provided continuously with the lower electrode constituting the piezoelectric element. .

In the thirty-third aspect, the distance between the lower electrode and the residual portion constituting the piezoelectric element can be made relatively small, and the piezoelectric layer is formed with a uniform thickness.

According to a thirty-fourth aspect of the present invention, in any one of the thirty-first to thirty- third aspects, the distance between the width-direction end face of the lower electrode and the width-direction end face of the remaining portion is larger than the thickness of the piezoelectric layer. The width of the lower electrode is smaller than the width of the lower electrode.

In the thirty-fourth aspect, the thickness of the piezoelectric layer in the width direction becomes substantially uniform, and the piezoelectric characteristics do not deteriorate.

A thirty-fifth aspect of the present invention is the liquid crystal display device according to any one of the thirty-first to thirty- fourth aspects, wherein the lower electrode extends in the longitudinal direction of the piezoelectric layer near an end of the pressure generating chamber extending to the peripheral wall. An end is present, and the distance until the lower electrode extending outward from the end becomes wider is wider than the thickness of the piezoelectric layer and smaller than the width of the lower electrode. Ink-jet recording head.

In the thirty-fifth aspect, the thickness of the piezoelectric layer near the longitudinal end of the pressure generating chamber becomes uniform, and even if the piezoelectric layer is patterned, the lower electrode below the piezoelectric layer does not become thin. .

According to a thirty-sixth aspect of the present invention, in any one of the thirty-first to thirty- fifth aspects, the width of the residual portion is at least 50% of the width of the partition wall between the adjacent pressure generating chambers. Ink-jet recording head.

In the thirty-sixth aspect, by forming the remaining portion with a predetermined width, the thickness of the piezoelectric layer is more reliably formed with a uniform thickness.

[0087] In a thirty-seventh aspect of the present invention, in any one of the thirty-sixth to thirty-sixth aspects, the lower electrode and the remaining portion are preferably
An ink jet recording head is formed in a region having a width of 50% or more of a region corresponding to a plurality of the pressure generating chambers arranged in parallel and partition walls on both sides in the width direction thereof.

In the thirty-seventh aspect, the thickness of the piezoelectric layer is reliably made uniform by setting the lower electrode and the remaining portion to predetermined sizes.

A thirty- eighth aspect of the present invention is the liquid crystal display device according to any one of the thirty-first to thirty- seventh aspects, wherein the lower electrode and the remaining portion are:
5 of the total area of the flow path forming substrate in which the pressure generating chamber is formed
An ink jet recording head is formed in an area of 0% or more.

In the thirty-eighth aspect, by setting the lower electrode and the remaining portion to predetermined sizes, the thickness of the piezoelectric layer is reliably made uniform.

[0091] 39 embodiment of the present invention, in any one of the embodiments of the 1 to 38, wherein the crystal structure of the piezoelectric layer is substantially the same as the insulating layer on the on the lower electrode In the ink jet recording head.

In the thirty-ninth aspect, the crystal state of the piezoelectric layer formed on the insulating layer is the same as the crystal state of the piezoelectric layer formed on the lower electrode. No extraordinary stresses occur at the boundaries.

A fortieth aspect of the present invention is the ink jet recording head according to the thirty-ninth aspect, wherein a crystal seed serving as a nucleus of a crystal of the piezoelectric layer is formed on a surface of the insulating layer. It is in.

In the fortieth aspect, the crystal structure of the piezoelectric layer is oriented in one direction by the crystal seeds and is formed substantially uniformly, thereby preventing the occurrence of cracks and the like.

A forty-first aspect of the present invention is the ink jet recording head according to the forty-fourth aspect, wherein the crystal seeds are formed in an island shape.

In the forty-first aspect, the crystal of the piezoelectric layer grows from the island-like crystal seed.

A forty-second aspect of the present invention is the ink-jet recording apparatus according to any one of the third to forty-first aspects, wherein a second insulating layer is provided outside an end of the lower electrode. In the recording head.

In the forty-second aspect, the thickness of the piezoelectric layer near the end of the lower electrode does not become thin, and dielectric breakdown due to electric field concentration of the piezoelectric layer is prevented.

A forty-third aspect of the present invention is the ink jet recording head according to the forty- second aspect, wherein the second insulating layer has substantially the same thickness as the lower electrode.

In the forty-third aspect, a step between the lower electrode and the second insulating layer is small, and a piezoelectric layer having a substantially uniform film thickness can be formed thereon.

The forty-fourth aspect of the present invention relates to the forty- second or forty-third.
In the above aspect, the second insulating layer is made of an insulating material different from the insulating layer.

In the forty-fourth aspect, the second insulating layer exhibits a function irrespective of the type of insulating material.

A forty- fifth aspect of the present invention is the ink jet printer according to any one of the third to forty-first aspects, wherein a thick film portion is provided on the insulating layer outside an end of the lower electrode. In the recording head.

In the forty-fifth aspect, since the thickness of the piezoelectric layer near the end of the lower electrode does not become thin, dielectric breakdown due to electric field concentration of the piezoelectric layer can be prevented.

A forty-sixth aspect of the present invention is the ink jet recording head according to the forty-fifth aspect, wherein the thick film portion has substantially the same thickness as the lower electrode.

In the forty-sixth aspect, a step between the lower electrode and the thick film portion is small, and a piezoelectric layer having a substantially uniform film thickness can be formed thereon.

A forty-seventh aspect of the present invention is the liquid crystal display device according to any one of the third to forty-first aspects, wherein a thickness of the lower electrode is gradually reduced toward an outside of the piezoelectric active portion at an end of the lower electrode. An ink jet type recording head is provided with a gradually decreasing film thickness portion.

In the forty-seventh aspect, since the gradually decreasing thickness is provided at the end of the lower electrode, the thickness of the piezoelectric layer formed near the end of the lower electrode does not become thin. In addition, dielectric breakdown near the end of the piezoelectric active portion is prevented.

[0109] 48th aspect of the present invention, in the embodiment of the 47th, the film AtsuSusumu calamus is characterized in that the thickness of the lower electrode is a continuously sloped surface that Susumusho In the ink jet recording head.

In the forty-eighth aspect, since the piezoelectric layer is formed along the inclined surface of the gradually decreasing thickness, the thickness of the piezoelectric layer at the end of the piezoelectric active portion does not become thin.

[0111] 49 embodiment of the present invention, in the embodiment of the 47th, the film AtsuSusumu calamus is ink jet recording head thickness of the lower electrode is characterized in that it Susumusho stepwise It is in.

In the forty-ninth aspect, the piezoelectric layer is formed along the shape of the portion having a gradually decreasing thickness, and has substantially the same thickness as the other portions.

[0113] The 50 aspect of the present invention, in the embodiment of the 47th, the film AtsuSusumu calamus is characterized in that the thickness of the lower electrode is continuously an inclined curved surface Susumusho In the ink jet recording head.

In the fiftieth aspect, the piezoelectric layer is formed along the shape of the tapered portion and has a thickness substantially the same as the other portions.

[0115] 51 embodiment of the present invention, in any one of the embodiments of the 47-50, the thickness of the piezoelectric layer formed on the film thickness Susumusho part, than the thickness of the other portion The ink jet recording head is characterized in that it is also thick.

In the fifty-first aspect, there is no electric field concentration in the piezoelectric layer near the end of the piezoelectric active portion, and dielectric breakdown is prevented.

According to a fifty-second aspect of the present invention, in any one of the sixth to fifty-first aspects, the structure near the one end of the piezoelectric active portion is also provided on the other end side. In the recording head.

In the fifty-second aspect, similarly to the one end of the piezoelectric active portion, the other end is prevented from being broken.

According to a fifty-third aspect of the present invention, in any one of the sixth to the fifty-first aspects, the other end of the piezoelectric active portion is formed by an end of the piezoelectric layer and the upper electrode. An end of the piezoelectric active portion is covered with a discontinuous piezoelectric layer that is discontinuous from the piezoelectric layer.

In the fifty-third aspect, the end of the piezoelectric active portion is protected by the discontinuous piezoelectric layer, and peeling of the piezoelectric layer and the upper electrode is prevented.

According to a fifty-fourth aspect of the present invention, in any one of the sixth to fifty-first aspects, the other end of the piezoelectric active portion is formed by an end of the piezoelectric layer and the upper electrode. An end of the piezoelectric active part is fixed by an adhesive in an ink jet recording head.

In the fifty-fourth aspect, the end of the piezoelectric active portion is fixed, and peeling of the piezoelectric layer and the upper electrode is prevented.

In a fifty-fifth aspect of the present invention, in any one of the first to fifty-fourth aspects, the pressure generating chamber is formed in a silicon single crystal substrate by anisotropic etching, and the lower electrode,
An ink jet recording head is characterized in that each of the piezoelectric layer and the upper electrode is formed by film formation and lithography.

In the fifty-fifth aspect, an ink jet recording head having high-density nozzle openings can be manufactured relatively easily in large quantities.

A fifty-sixth aspect of the present invention is directed to an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to fifty-fifth aspects.

According to the fifty-sixth aspect, an ink jet recording head having improved head reliability can be realized.

[0127]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.

(Embodiment 1) FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view thereof and a longitudinal section of one pressure generating chamber. FIG.

As shown in the figure, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation of (110) in this embodiment. As the flow path forming substrate 10, usually 150 to 3
A thickness of about 00 μm is used.
Those having a thickness of about 0 to 280 μm, more preferably about 220 μm are suitable. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall between the adjacent pressure generating chambers.

One surface of the flow path forming substrate 10 is an opening surface, and the other surface is formed with an elastic film 50 of 1-2 μm in thickness made of silicon dioxide previously formed by thermal oxidation.

On the other hand, the opening surface of the flow path forming substrate 10 is anisotropically etched on a silicon single crystal substrate,
A nozzle opening 11 and a pressure generating chamber 12 are formed.

Here, in the anisotropic etching, when a silicon single crystal substrate is immersed in an alkaline solution such as potassium hydroxide, the substrate is gradually eroded and the first (1) plane perpendicular to the (110) plane is etched.
An (11) plane and a second (111) plane which forms an angle of about 70 degrees with the first (111) plane and forms an angle of about 35 degrees with the (110) plane appear, and (110) This is performed by utilizing the property that the etching rate of the (111) plane is about 1/180 compared to the etching rate of the plane. By such anisotropic etching, precision processing can be performed based on the depth processing of a parallelogram formed by two first (111) planes and two oblique second (111) planes. , The pressure generating chambers 12 can be arranged at a high density.

In this embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane, and the short side is formed by the second (111) plane. The pressure generating chamber 12 is provided on the flow path forming substrate 1.
It is formed by etching until it reaches the elastic film 50 almost through 0. The amount of the elastic film 50 that is attacked by the alkaline solution for etching the silicon single crystal substrate is extremely small.

On the other hand, each nozzle opening 11 communicating with one end of each pressure generating chamber 12 is formed narrower and shallower than the pressure generating chamber 12. That is, the nozzle opening 11 is formed by partially etching (half-etching) the silicon single crystal substrate in the thickness direction. In addition,
Half etching is performed by adjusting the etching time.

Here, the size of the pressure generating chamber 12 for applying the ink droplet ejection pressure to the ink and the size of the nozzle opening 11 for ejecting the ink droplet depend on the amount of the ejected ink droplet, the ejection speed, and the ejection frequency. Optimized. For example,
When recording 360 ink droplets per inch, the nozzle openings 11 need to be formed with a groove width of several tens of μm with high accuracy.

Each pressure generating chamber 12 and a common ink chamber 31 described later are connected to each pressure generating chamber 1 of the sealing plate 20 described later.
The ink is supplied from a common ink chamber 31 through the ink supply communication port 21 formed at a position corresponding to one end of the pressure generation chamber 12. Distributed to

The sealing plate 20 has, for example, a thickness of 0.1 to 1 mm and a linear expansion coefficient of 300.degree. , For example, 2.5-4.5 [× 10 ⁻⁶ / ° C.]. In addition, the ink supply communication port 21
Each of the pressure generating chambers 1 is, as shown in FIGS.
It may be one slit hole 21A crossing the vicinity of the second ink supply side end or a plurality of slit holes 21B. The sealing plate 20 is provided on one side with the flow path forming substrate 10.
, And also serves as a reinforcing plate for protecting the silicon single crystal substrate from impacts and external forces. Also, sealing plate 2
0 forms one wall surface of the common ink chamber 31 on the other surface.

The common ink chamber forming substrate 30 forms the peripheral wall of the common ink chamber 31, and is formed by punching a stainless steel plate having an appropriate thickness according to the number of nozzles and the ink droplet ejection frequency. . In the present embodiment, the thickness of the common ink chamber forming substrate 30 is 0.2 mm.

The ink chamber side plate 40 is made of a stainless steel substrate, and one surface of the ink chamber side plate 40 constitutes one wall surface of the common ink chamber 31. In the ink chamber side plate 40, a thin wall 41 is formed by forming a concave portion 40a by half etching on a part of the other surface, and an ink introduction port 42 for receiving ink supply from the outside is punched and formed. ing. The thin wall 41 is for absorbing pressure generated at the time of ink droplet ejection toward the side opposite to the nozzle opening 11, and is unnecessary for the other pressure generating chambers 12 via the common ink chamber 31. Prevents positive or negative pressure from being applied.
In the present embodiment, the ink chamber side plate 40 is made 0.2 mm in consideration of rigidity required at the time of connection between the ink introduction port 42 and an external ink supply means, and a part of the thickness is 0.02 mm.
The thickness of the ink chamber side plate 40 may be 0.02 mm from the beginning in order to omit the formation of the thin wall 41 by half etching.

On the other hand, the thickness of the elastic film 50 on the side opposite to the opening surface of the flow path forming substrate 10 is, for example, about 0.5 μm.
A lower electrode film 60, a piezoelectric film 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.1 μm are formed by lamination in a process to be described later.
0. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80. Generally, one of the electrodes of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric film 70 are patterned for each pressure generating chamber 12. Here, a portion which is constituted by one of the patterned electrodes and the piezoelectric film 70 and in which a piezoelectric strain is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion 320. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. In any case, the piezoelectric active portion is formed for each pressure generating chamber. Also, here
The combination of the piezoelectric element 300 and the vibration plate whose displacement is generated by driving the piezoelectric element 300 is referred to as a piezoelectric actuator.

Here, a process for forming the piezoelectric film 70 and the like on the flow path forming substrate 10 made of a silicon single crystal substrate will be described with reference to FIGS. 4 and 6 are cross-sectional views in the width direction of the pressure generating chamber 12, and FIG.
Is a longitudinal sectional view of the pressure generating chamber 12. FIG.

First, as shown in FIG. 4 (a), a wafer of a silicon single crystal
Thermal oxidation is performed in a diffusion furnace at 0 ° C. to form an elastic film 50 made of silicon dioxide.

Next, as shown in FIG. 4B, a lower electrode film 60 is formed by sputtering. As a material of the lower electrode film 60, platinum or the like is preferable. This is because a piezoelectric film 70 described later, which is formed by a sputtering method or a sol-gel method,
After film formation, 600 to 10 in an air atmosphere or an oxygen atmosphere
This is because it is necessary to perform crystallization by firing at a temperature of about 00 ° C. That is, the material of the lower electrode film 60 must be able to maintain conductivity under such a high temperature and oxidizing atmosphere. In particular, when the piezoelectric film 70 is made of lead zirconate titanate (PZT), It is desirable that the change in conductivity due to the diffusion of lead oxide is small, and for these reasons, platinum is preferred.

Next, as shown in FIGS. 4 (c) and 5,
The lower electrode film 60 is patterned to form an entire pattern, and is extended from a region facing the pressure generating chamber 12 to a region on the peripheral wall in a region corresponding to the vicinity of one longitudinal end of each pressure generating chamber 12. The lower electrode film 61 for wiring is formed.

Next, as shown in FIG. 4D, a piezoelectric film 70 is formed. The crystal of the piezoelectric film 70 is preferably oriented. For example, in the present embodiment, a so-called sol-gel method is used in which a so-called sol in which a metal organic substance is dissolved and dispersed in a catalyst is applied, dried and gelled, and further fired at a high temperature to obtain a piezoelectric film 70 made of a metal oxide. To form a piezoelectric film 70 in which crystals are oriented. As a material of the piezoelectric film 70, a lead zirconate titanate-based material is suitable when used in an ink jet recording head. The method for forming the piezoelectric film 70 is not particularly limited, and may be, for example, a sputtering method.

After forming a precursor film of lead zirconate titanate by a sol-gel method or a sputtering method,
A method of growing crystals at a low temperature by a high-pressure treatment method in an alkaline aqueous solution may be used.

In any case, unlike the bulk piezoelectric, the piezoelectric film 70 thus formed has a preferentially oriented crystal, and in the present embodiment, the piezoelectric film 70 has a crystal orientation. It is formed in a column shape. Note that the preferential orientation refers to a state in which a crystal orientation direction is not disordered and a specific crystal plane is oriented in a substantially constant direction. In addition, a crystal having a columnar thin film refers to a state in which substantially columnar crystals are gathered in a plane direction with their central axes substantially aligned in the thickness direction to form a thin film. Of course, it may be a thin film formed of preferentially oriented granular crystals. The thickness of the piezoelectric film manufactured in the thin film process is generally 0.5 to 5 μm.

Next, as shown in FIG. 4E, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a material having high conductivity, and can use many metals such as aluminum, gold, nickel, and platinum, and a conductive oxide. In the present embodiment, platinum is formed by sputtering.

Thereafter, as shown in FIG. 6A, only the piezoelectric film 70 and the upper electrode film 80 are etched to pattern the piezoelectric active portion 320. The above is the film forming process. After forming the film in this manner, FIG.
As shown in (b), the silicon single crystal substrate is anisotropically etched with the above-described alkali solution to form the pressure generating chamber 12 and the like.

FIG. 7 shows a plan view and a cross section of a main part of the ink jet recording head thus formed.

As shown in FIG. 7, the lower electrode film 60 constituting the piezoelectric element 300 has a plurality of pressure generating chambers 12 arranged in parallel.
The end portion of the lower electrode film 60 is an end portion of the piezoelectric active portion 320. In the region facing the vicinity of the end of the other end in the longitudinal direction of the pressure generating chamber 12, the piezoelectric element of the piezoelectric element is discontinuous with the lower electrode film 60 from the region facing the pressure generating chamber 12 to the peripheral wall. A wiring lower electrode film 61 used as a wiring is provided for each pressure generating chamber 12.

Here, the lower electrode film 60 and the wiring lower electrode film 6
It is preferable that the interval of 1 and the interval between the lower electrode films 61 for wiring are formed to be narrow enough to maintain at least their respective insulation strengths.

On the other hand, the piezoelectric film 70 and the upper electrode film 80
In this embodiment, the upper electrode film 80 and the lower electrode film for wiring are provided in a region facing the pressure generating chamber 12, and one end thereof is extended to the lower electrode film 61 for wiring. 61 are connected. The shape of the lower electrode film 61 for wiring is not particularly limited.
As shown in (1), it is preferable that the pressure generating chamber 12 is formed so as to cover at least the edge portion thereof. Accordingly, the rigidity of the diaphragm is kept high, and the occurrence of cracks in the diaphragm can be prevented.

In such a configuration, the piezoelectric film 70 and the upper electrode film 80 existing on the lower electrode film 60 are
The piezoelectric film 70 and the upper electrode film 80 are provided continuously from the longitudinal end of the piezoelectric active portion 320 on the region where the lower electrode film 60 is removed and on the lower electrode film 61 for wiring.
Is a piezoelectric inactive portion 330 having a piezoelectric film but not being substantially driven.

Therefore, the boundary between the pressure generating chamber 12 and the peripheral wall is the piezoelectric non-active section 330 which is not driven by the application of the voltage to the piezoelectric active section 320. Film 70 at the longitudinal end of the piezoelectric film 70
There is no danger of peeling, etc., and generation of cracks due to repeated displacement. Further, since the piezoelectric film 70 and the upper electrode film 80 are extended to above the wiring lower electrode film 61, it is not necessary to form a contact hole. That is, the upper electrode film 80
It is not necessary to form an insulator film on which a contact hole is provided. Therefore, a decrease in displacement due to the thickness of the insulator film of the piezoelectric active portion 32 is eliminated. In addition, the number of manufacturing steps can be reduced, and costs can be reduced.

A number of chips are simultaneously formed on one wafer by a series of film formation and anisotropic etching of the piezoelectric active section 320 and the pressure generating chamber 12 described above.
After the process is completed, the substrate is divided into each of the flow path forming substrates 10 having one chip size as shown in FIG. Further, the divided flow path forming substrate 10 is divided into a sealing plate 20 and a common ink chamber forming substrate 3.
0 and the ink chamber side plate 40 are sequentially bonded and integrated to form an ink jet recording head.

The ink jet head thus configured takes in ink from an ink inlet 42 connected to external ink supply means (not shown),
After filling the interior from 1 to the nozzle opening 11 with ink, a voltage is applied between the upper electrode film 80 and the lower electrode film 60 according to a recording signal from an external drive circuit (not shown), By bending and deforming the lower electrode film 60 and the piezoelectric film 70, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 11.

In the present embodiment, the piezoelectric film 70 and the upper electrode film 80 are formed in the region facing the pressure generating chamber 12, but the invention is not limited to this. For example, the region facing the peripheral wall may be formed. It may be extended to. Needless to say, the same effect as described above can be obtained by such a configuration.

In the above-described example, the piezoelectric inactive portion 3
Although 30 was formed by removing the lower electrode film 60,
The present invention is not limited to this. For example, the piezoelectric film 70 and the upper electrode film 8
Alternatively, the piezoelectric film 70 may be formed by providing a low dielectric insulating layer between 0 and 0, or may be formed by partially doping the piezoelectric film 70 to make it inactive.

(Embodiment 2) FIG. 9 is a sectional view of a main part of an ink jet recording head according to Embodiment 2.

The present embodiment is another example of the wiring method of the piezoelectric active portion 320. As shown in FIG. 9, the lower electrode film 61 for wiring is not provided in the region facing the pressure generating chamber 12. ,
It is the same as Embodiment 1 except that it is provided on the peripheral wall.

Of course, even in such a configuration, the same effect as in the first embodiment can be obtained.

In the above embodiment, the lower electrode film 60
The lower electrode film 61 for wiring is provided on the outer side of the substrate. However, the present invention is not limited to this. For example, as shown in FIG. A lead electrode 100 that is connected and extends to the end of the substrate may be separately provided.

The piezoelectric film 7 forming the piezoelectric inactive portion 330 extending from the end of the pressure generating chamber 12 to the peripheral wall.
0 and the upper electrode film 80 are not particularly limited.
As shown in FIG. 11, it is preferable that a wide portion 331 wider than the pressure generating chamber 12 near the end of the pressure generating chamber 12 covers the end of the pressure generating chamber 12. Thereby, the rigidity of the diaphragm near the end of the pressure generating chamber 12 is kept high, and the occurrence of cracks in the diaphragm can be prevented.

(Embodiment 3) FIG. 12 is a plan view and a cross-sectional view of a main part of an ink jet recording head according to Embodiment 3.

In the present embodiment, as shown in FIG. 12, the lower electrode film 60 is not provided on the lower side of the piezoelectric inactive portion 330 in the region facing the boundary between the end of the pressure generating chamber 12 and the peripheral wall. This is an example in which a continuous discontinuous lower electrode 62 is provided. That is, in the vicinity of the end of the pressure generating chamber 12 on the side where the piezoelectric film 70 and the upper electrode film 80 are extended, the lower electrode film removing portion 340 from which the lower electrode film 60 is removed is provided, for example, in the present embodiment. In the present embodiment, a narrow groove is provided along the shape of the pressure generating chamber 12 in the direction in which the pressure generating chambers 12 are arranged.
Embodiment 2 differs from Embodiment 2 in that the lower electrode film at the boundary between the end of the pressure generating chamber 12 and the peripheral wall is a discontinuous lower electrode film 62 that is discontinuous with the lower electrode film 60 of the piezoelectric active section 320. The same is true.

Here, the lower electrode film 60 and the discontinuous lower electrode film 6
It is necessary that the width of the lower electrode film removing part 340 that separates the lower electrode film 2 be at least as wide as the insulation strength between the lower electrode film 60 and the discontinuous lower electrode film 62 can be maintained. It is preferable to maintain rigidity.

In such a configuration, the discontinuous lower electrode film 62 becomes a floating electrode which is not electrically connected to any other components, and the piezoelectric film 70 and the upper electrode film 80 existing on the lower electrode film 60. Constitute the piezoelectric active portion 320 which is a substantial driving portion, and the piezoelectric film 70 and the upper electrode film 80 on the discontinuous lower electrode film 62 are not strongly driven.

Therefore, the boundary between the pressure generating chamber 12 and the peripheral wall is not strongly driven by the application of the voltage to the piezoelectric active portion 320, and the diaphragm at the longitudinal end of the pressure generating chamber 12 is not vibrated. Has high rigidity, and it is possible to prevent breakage of the diaphragm or the piezoelectric film 70 at this portion.

In this embodiment, the discontinuous lower electrode film 6
2 is formed over the direction in which the plurality of pressure generating chambers 12 are arranged in parallel, but is not limited to this. For example, as shown in FIG. Is also good. Accordingly, the piezoelectric film 70 and the upper electrode film 80 on the discontinuous lower electrode 61 become the piezoelectric non-active portion 330 in which the piezoelectric film 70 and the upper electrode film 80 are not completely driven. Can be prevented.

In this embodiment, the discontinuous lower electrode film 6
2 is a floating electrode that is not electrically connected to other parts, but is not limited to this. For example,
It may be connected to the electrode layer via a resistor having a predetermined resistance value so that the charging time constant is larger than the drive pulse of the piezoelectric active section 320.

(Embodiment 4) FIG. 14 is a plan view of an essential part of an ink jet recording head according to Embodiment 4. FIG.

In this embodiment, as shown in FIG. 14, an intermediate electrode film 63 which is separated by a lower electrode film removing portion 340 and is not connected to any other is provided between each lower electrode film 61 for wiring. The configuration is the same as that of the first embodiment except for the presence.

With such a configuration, the width of the lower electrode film removing portion 340 that separates each lower electrode film 61 for wiring can be reduced. That is, since the intermediate electrode film 63 is provided between the lower electrode films 61 for wiring, even if the width of the lower electrode film removing portion 340 is reduced, the insulation strength thereof can be reliably maintained. Thereby, the rigidity of the diaphragm is further increased, and similarly to the above-described embodiment, it is possible to prevent the diaphragm from being broken or the piezoelectric film 70 from being broken at the boundary between the pressure generating chamber 12 and the peripheral wall.

In the above embodiment, the lower electrode film 60
And lower electrode film removing section 340 between lower electrode film 61 for wiring
Are formed with a width that can maintain the insulation strength between each lower electrode film 60 and the lower electrode film 61 for wiring.
As shown in FIG. 15, for example, the upper electrode film 80 is removed at a portion where dielectric breakdown is likely to occur, such as on both sides in the width direction of the piezoelectric active portion 320, and the piezoelectric film 70 that is not substantially driven is left. An inactive portion 350 may be provided.
Thereby, the insulation strength can be more reliably maintained. Note that, of course, if the piezoelectric film 70 is not driven,
Needless to say, the upper electrode film 80 need not be removed.

(Embodiment 5) FIG. 16 is a plan view and a cross-sectional view of a main part of an ink jet recording head according to Embodiment 5.

In the present embodiment, as shown in FIG. 16, instead of providing the lower electrode film 61 for wiring, the piezoelectric
The piezoelectric film 70 and the upper electrode film 80 which are 30 extend from the region facing the pressure generating chamber 12 to the peripheral wall, and although not shown, near the end, for example, external wiring such as a flexible cable and the upper electrode The film 80 is directly connected. Further, the lower electrode film 60 is basically provided in a region facing the pressure generating chamber 12 and the piezoelectric inactive portion 3
The third embodiment is the same as the first embodiment except that it extends from the end opposite to 30 to the peripheral wall of the pressure generating chamber 12 and serves as a common electrode for each piezoelectric element 300.

With such a configuration, the same effects as those of the above-described embodiment can be obtained. Also, the lower electrode film 60
And the upper electrode film 80 are extended from the longitudinal end of the pressure generating chamber 12 to the peripheral wall in the opposite direction, so that the lower electrode film 60 and the upper electrode film 80 can be easily wired without short-circuiting. Can be pulled out.

Further, as in the present embodiment, the piezoelectric film 70
Is formed continuously from the pressure generating chamber 12 to the peripheral wall, it is preferable that the crystal structure of the piezoelectric film 70 is the same on the lower electrode film 60 and on the elastic film 50. Therefore, it is preferable to form the piezoelectric film 70 as follows.

That is, as shown in FIG. 17A, before the piezoelectric film 70 is formed, the lower electrode film 60 and the elastic film 50 are formed.
After a crystal seed 75 made of titanium or titanium oxide is formed in an island shape by sputtering, an amorphous piezoelectric precursor layer 71 is formed as shown in FIG. As shown in (c), the piezoelectric film 70 is crystallized by firing.

When the method of forming crystal seeds 75 is used, the elastic film 50 is selected from materials having good adhesion to the piezoelectric film 70, for example, constituent elements of the piezoelectric film 70. Oxides or nitrides of at least one element,
For example, it is preferably formed of zirconium oxide or the like.

Here, when forming the piezoelectric film 70 on the lower electrode film 60 such as platinum, a technique of forming a crystal seed and orienting the crystal in substantially one direction has been previously filed. However, in a special structure in which the piezoelectric film 70 is formed after the lower electrode film 60 is patterned as in the present embodiment, even if a crystal seed is previously formed on the lower electrode film 60, On the film 50, there is a problem that the crystal structure is different and cracks are easily generated. Therefore, in the present embodiment, the crystal structure of the piezoelectric film 70 on the lower electrode film 60 and the elastic film 50 is made substantially the same by forming the crystal seed 75 also on the elastic film 50, thereby generating cracks and Prevent the generation of abnormal stress. The elastic film 50
The upper crystal seed may be formed simultaneously after patterning the lower electrode film 60, or may be separately formed only on the elastic film 50 after forming the crystal seed on the lower electrode film 60 and further patterning the same. Good. In the case where the crystal seeds are separately formed, the crystal seeds may be formed in a film shape instead of an island shape.

(Embodiment 6) FIG. 18 is a plan view of a main part of an ink jet recording head according to Embodiment 6.

In the present embodiment, as shown in FIG. 18, a piezoelectric non-active portion 330 is provided in a region facing the peripheral wall in the width direction of the pressure generating chamber 12 from a substantially central portion of the piezoelectric active portion 320. Except for this, the configuration is the same as that of the fifth embodiment.

With such a configuration, in addition to the same effects as those of the above-described embodiment, the current flowing to the piezoelectric film 70 near the connecting portion between the piezoelectric active portion 320 and the piezoelectric non-active portion 330 can be obtained. Concentration can be suppressed, and breakage of the piezoelectric film 70 and the like can be prevented.

(Embodiment 7) FIG. 19 is a plan view of a main part of an ink jet recording head according to Embodiment 7. FIG.

In this embodiment, as shown in FIG. 19, the width of the piezoelectric non-active portion 330, which is narrower than the width of the piezoelectric active portion 320, is formed in a region facing the longitudinal end of the pressure generating chamber 12. The fifth embodiment is the same as the fifth embodiment except that the portion 332 is formed.

In such a configuration, since the regulation of the displacement of the diaphragm at the end of the pressure generating chamber 12 is eased, the displacement of the diaphragm by driving the piezoelectric active portion 320 at this end is improved. can do.

In this embodiment, the piezoelectric non-active portion 3
Although the upper electrode film 80 and the piezoelectric film 70 of 30 are formed to be narrow, the present invention is not limited to this.
Only 0 may be formed narrow.

(Eighth Embodiment) FIG. 20 is a plan view and a sectional view of a main part of an ink jet recording head according to an eighth embodiment.

In this embodiment, as shown in FIG. 20, near the end of the pressure generating chamber 12, the piezoelectric active portion 320
Lower electrode film 60 at the boundary with the piezoelectric inactive portion 330
In the figure, both sides in the width direction of the pressure generating chamber 12 are removed to form a narrow portion 64 which is narrower than other portions. In the present embodiment, the narrow portion 64 is formed to be narrower than the width of the piezoelectric film 70 in a region facing the pressure generating chamber 12, and both end surfaces in the width direction are covered with the piezoelectric film 70. Except for this, it is the same as the first embodiment.

With such a configuration, the upper electrode film 80 and the lower electrode film 60 are surely formed near the end of the lower electrode film 60 of the pressure generating chamber 12, that is, at the end of the piezoelectric active portion 320. And no discharge occurs between them. Therefore, dielectric breakdown of the piezoelectric film 70 can be prevented.

(Embodiment 9) FIGS. 21A and 21B are a plan view and a sectional view of a main part of an ink jet recording head according to Embodiment 9. FIG.

In the present embodiment, as shown in FIG. 21, the narrow portion 64 of the lower electrode film 60 is formed in the region facing the pressure generating chamber 12, but is smaller than the width of the piezoelectric film 70. Embodiment 8 is the same as Embodiment 8 except that the piezoelectric film 70 and the upper electrode film 80 are formed to have a wide width and extend to the peripheral wall via the narrow portion 64 to form the piezoelectric inactive portion 330. is there.

Here, as shown by a graph generally called a Paschen curve, it is known that no discharge occurs between the electrodes if the distance between the electrodes is equal to or less than a certain value. For example, in the present embodiment, the distance between the width direction end face of the narrow portion 64 and the width direction end face of the upper electrode film 80 may be about 10 μm or less, and in the present embodiment, these distances are about 7 μm. I did it.

Therefore, even in such a configuration, similarly to the eighth embodiment, discharge between the upper electrode film 80 and the lower electrode film 60 at the longitudinal end of the pressure generating chamber 12 is prevented.
The dielectric breakdown of the piezoelectric film 70 is suppressed.

In the present embodiment, the narrow portion 64 is provided in the region facing the pressure generating chamber 12. However, the present invention is not limited to this, and the narrow portion 64 is provided between the upper electrode film 80 and the lower electrode film 60. Any distance that does not cause discharge is sufficient.
As shown in (c), the narrow portion 64 may be extended to the widthwise peripheral wall of the pressure generating chamber 12.

(Embodiment 10) FIG.
1 is a plan view of an ink jet recording head according to the first embodiment.

In this embodiment, as shown in FIG. 22, the narrow portion 64 of the lower electrode film 60 has a substantially trapezoidal shape in which the width gradually decreases toward the distal end, and at least the distal end has the pressure generating chamber 1.
Embodiment 8 is the same as Embodiment 8 except that the piezoelectric film 70 is covered in the region opposed to 2.

As a result, at the end of the lower electrode film 60, the piezoelectric film 70 is easily thinned, and the electric field is easily concentrated, so that the dielectric breakdown of the piezoelectric film 70 is particularly likely to occur. Since the lower electrode film 60 and the upper electrode film 80 are insulated from each other by being covered by the piezoelectric film 70, no discharge occurs between them, and the dielectric breakdown of the piezoelectric film 70 can be prevented. it can.

(Embodiment 11) FIG.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 23, the piezoelectric film 70 and the upper electrode film 80 have a narrower width than the piezoelectric active portion 320 and face the peripheral wall from one longitudinal end of the pressure generating chamber 12. Piezoelectric body non-active portion 3 continuously extended to the region
The upper electrode film 80 is connected to the external wiring near the end. On the other hand, the lower electrode film 60 is basically formed so as to cover the region facing each pressure generating chamber 12, but the region where the piezoelectric film 70 and the upper electrode film 80 extend, that is, the piezoelectric material Embodiment 1 Except that the region where the inactive portion 330 extends is the lower electrode film removing portion 340 removed with a width smaller than the width of the pressure generating chamber 12.
Is the same as

Here, the portion where the piezoelectric film 70 and the upper electrode film 80 extend on the peripheral wall from the end of the pressure generating chamber 12 and the lower electrode film removing portion 340 are formed by the edge of the upper electrode film 80. A direction crossing from above the lower electrode film 60 to above the lower electrode removing portion 340;
It is preferable that the direction in which the upper electrode film 80 extends on the peripheral wall does not match. That is, it is preferable that the angle between the direction of the current flowing in the portion where the upper electrode film 80 crosses the lower electrode film 60 and the direction of the current flowing in the extended upper electrode film 80 be large. In the embodiment, the angle of the direction of the current flowing through these portions is about 90 °.

As described above, in the present embodiment, the lower electrode film 60 of the piezoelectric active portion 320 where the piezoelectric film 70 and the upper electrode film 80 extend to the peripheral wall is removed to remove the lower electrode film removing portion. In addition to 340, the other region facing the pressure generating chamber 12 was covered with the lower electrode film 60. As a result, there is no end of the lower electrode film 60 around the upper electrode film 80 constituting the piezoelectric active portion 320, and discharge does not easily occur.
Further, in the extending portion of the piezoelectric film 70 and the upper electrode film 80,
The direction of the current flowing in the portion where the upper electrode film 80 crosses the lower electrode film 60 does not match the direction of the current flowing in the extended upper electrode film 80.
The current flowing into the piezoelectric active portion 320 from the lower electrode film 60
Is spread and dispersed at the intersections with the head, thereby preventing dielectric breakdown of the piezoelectric film 70 due to electric field concentration or the like, and improving the durability and reliability of the head.

Also, for example, as shown in FIG. 24, the displacement suppression for suppressing the displacement of the piezoelectric active part 320 is provided on the upper electrode film 80 at the boundary between the piezoelectric active part 320 and the piezoelectric non-active part 330. A layer 110 may be provided. Accordingly, vibration at the end of the piezoelectric active part 320 can be suppressed, and the occurrence of cracks in the diaphragm due to driving of the piezoelectric active part 320 can be prevented. Further, the displacement suppressing layer 110 can be easily formed from, for example, the same material as that of the lead electrode 100 described above.

In the present embodiment, the lower electrode film 60 corresponding to the piezoelectric film 70 and the upper electrode film 80 is substantially rectangularly removed to form the lower electrode film removing portion 340. However, the present invention is not limited to this. For example, as shown in FIG. 25A, a substantially circular or substantially elliptical lower electrode film removing section 340 may be provided in a region facing the pressure generating chamber 12. Also,
In this case, the base portions of the piezoelectric film 70 and the upper electrode film 80 extending with a width smaller than that of the piezoelectric active portion 320 may be further removed to the inside of the piezoelectric active portion 320. Accordingly, the angle between the direction of the current flowing in the portion where the upper electrode film 80 crosses the lower electrode film 60 and the direction of the current flowing in the extended upper electrode film 80 increases, that is, the angle of the extended upper electrode film 80 increases. The direction in which the current flowing from the film 80 into the piezoelectric active portion 320 spreads increases, and the electric field applied between the upper electrode film 80 and the lower electrode film 60 is further dispersed.

For example, as shown in FIG. 25B, the shape of the lower electrode film removing portion 340 is made substantially semicircular, and the width of the longitudinal end of the piezoelectric active portion 320 is gradually reduced. Alternatively, the lower electrode film 60 and the upper electrode film 80 may intersect at the arc portion of the lower electrode film removing part 340. Even with such a configuration, the angle between the direction of the current flowing in the portion where the upper electrode film 80 crosses the lower electrode film 60 and the direction of the current flowing in the extended upper electrode film 80 increases. Therefore, similarly to the above, the electric field applied between the lower electrode film 60 and the upper electrode film 80 is dispersed.

As described above, the shapes of the lower electrode film removing portion 340 and the extending portions of the piezoelectric film 70 and the upper electrode film 80 are not particularly limited, but the current flowing through the extending portion of the upper electrode film 80 is not limited. And the direction of the current flowing in the portion crossing the lower electrode film 60 is preferably 5 ° to 180 °.

(Embodiment 12) FIG. 26 shows Embodiment 12 of the present invention.
FIG. 2 is a plan view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 26, the lower electrode film 60 is removed at a substantially central portion in the longitudinal direction on the peripheral walls on both sides in the width direction of the pressure generating chamber 12 to form a lower electrode film removing portion 340. That is, the piezoelectric film 70 and the upper electrode film 80 extend from the substantially central portion in the longitudinal direction of the piezoelectric active portion 320 to the lower electrode film removing portion 34.
The piezoelectric non-active portion 33 is extended to the peripheral wall through
It is 0. Also, the upper electrode film 8 extending on the peripheral wall
Embodiment 11 is the same as Embodiment 11 except that 0 is connected to an external wiring via the lead electrode 100.

Thus, the piezoelectric film 70 and the upper electrode film 8
By extending 0 from the center of the pressure generating chamber 12 in the width direction, the drive loss of the piezoelectric active section 320 can be suppressed, the rise can be made faster, and the ink ejection characteristics can be improved. Further, it is needless to say that the same effect as that of the eleventh embodiment can be obtained.

(Embodiment 13) FIG.
FIG. 2 is a plan view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 27, the piezoelectric film 70 and the upper electrode film 80 of the piezoelectric active portion 320 extend from both sides in the width direction of the pressure generating chamber 12 to the peripheral wall. Embodiment 1 except for the inactive unit 330
Same as 1.

According to such a configuration, Embodiment 11
The same effect can be obtained. In addition, since the piezoelectric film 70 and the upper electrode film 80 extend from both sides of the pressure generating chamber 12 on the peripheral wall, the drive loss of the piezoelectric active portion 320 can be further suppressed, and the ink ejection characteristics can be improved. Can be improved.

(Embodiment 14) FIG.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 28, an example in which a residual portion 65 made of the same layer as the lower electrode film 60 is provided on the partition wall of the pressure generating chamber 12 is used. The remaining portion 65 is provided continuously with the lower electrode film 60 of the piezoelectric active portion 320 in the longitudinal direction of the pressure generating chamber 12. That is, by providing the lower electrode film removing portion 340 in which the lower electrode film 60 is removed in a region facing the boundary with the partition on both sides in the width direction of the pressure generating chamber 12, the residual portion 65 is formed in a region facing the partition. The configuration is the same as that of the fifth embodiment except for the above.

Here, the distance h ₁ between the side surface of the lower electrode film 60 in the width direction and the side surface of the remaining portion 65 in the width direction, and the side surface of the longitudinal end of the piezoelectric film 70 and the peripheral wall. It is preferable that the interval h ₂ until the extended lower electrode film 60 becomes wider is wider than the thickness of the piezoelectric film 70 and narrower than the width of the lower electrode film 60.

Further, the width of the remaining portion 65 is 50 times the width of the partition wall.
% Or more, more preferably 80% or more.
% Or more. Further, it is preferable that the lower electrode film 60 or the remaining portion 65 is formed in at least 50% or more of a region facing the plurality of pressure generating chambers 12 arranged in parallel and partitions on both sides in the width direction.

In the present embodiment, near the end of the pressure generating chamber 12 on the side where the piezoelectric film 70 and the upper electrode film 80 extend, the lower electrode film 60 extends in the direction in which the pressure generating chamber 12 is juxtaposed. The lower electrode film on the peripheral wall of the pressure generating chamber 12 is discontinuous with the lower electrode film 60 constituting the piezoelectric active portion 320. A continuous lower electrode film 62 is formed. The discontinuous lower electrode film 6
2, a piezoelectric film 70 and an upper electrode film 80 are extended to form a piezoelectric non-active portion 330. Although not shown, the upper electrode film 80 and an external wiring are connected near an end thereof. .

With such a configuration, the same effect as in the above-described embodiment can be obtained. Further, in the present embodiment,
Since the remaining portions 65 are preferably provided in the regions facing the partition walls on both sides in the width direction of the pressure generating chamber 12 under the above-described conditions, the region where the lower electrode film 60 is removed is very small, and the patterning is performed. The piezoelectric film 70 on the lower electrode film 60
Is formed, the film thickness of the piezoelectric film 70 is substantially uniform overall, and the film thickness of the piezoelectric film 70 is not locally reduced.

The distance between the side surface of the longitudinal end of the piezoelectric film 70 and the width of the lower electrode film 60 extending on the peripheral wall is relatively small, so that the pressure generating chamber 12 The thickness of the piezoelectric film 70 becomes uniform even near the longitudinal end. Accordingly, even when the piezoelectric film 70 near the end on the side from which the lower electrode film 60 is drawn out of the pressure generating chamber 12 is etched by an etching method having no selectivity such as ion milling, the lower side of the piezoelectric film 70 is also used. The lower electrode film 60 is not removed at the same time, and the film thickness is not reduced. Therefore, the rigidity of the lower electrode film 60 near the end of the pressure generating chamber 12 is not reduced, and the durability is improved. Such an effect is particularly remarkable when the piezoelectric film 70 is formed by the spin coating method such as the sol-gel method as described above.
It may be formed by a method D (organic metal thermal coating decomposition method) or the like.

(Embodiment 15) FIG.
FIG. 2 is a plan view of a main part of an ink jet recording head according to the first embodiment.

In this embodiment, as shown in FIG. 29, the remaining portion 65 provided on the partition wall in the width direction of the pressure generating chamber 12 is provided.
However, the present embodiment is the same as Embodiment 14 except that the lower electrode film 60 constituting the piezoelectric active portion 320 is provided continuously with the discontinuous lower electrode film 62.

With such a structure, the piezoelectric film 70
Can be obtained, and the same effect as that of the fourteenth embodiment can be obtained.

(Embodiment 16) FIG.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

As shown in FIG. 30, in the present embodiment, an end of the lower electrode film 60 which is a boundary between the piezoelectric active portion 320 and the piezoelectric non-active portion 330 is provided outside the piezoelectric active portion 320. The thickness of the lower electrode film 60 gradually decreases.
This embodiment is the same as the first embodiment except that is provided.
The shape of the tapered portion 66 is not particularly limited. For example, in this embodiment, the thickness of the lower electrode film 60 is an inclined surface where the film thickness is continuously reduced.

As described above, in the present embodiment, the thickness of the lower electrode film 60 which is the end of the piezoelectric active portion 320 is gradually reduced toward the outside of the piezoelectric active portion 320. A small portion 66 is provided. Thereby, the piezoelectric film 70
Is formed along the shape of the lower electrode film 60 including the tapered portion 66, and the overall film thickness becomes substantially uniform. That is, the thickness of the piezoelectric film 70 at the end of the lower electrode film 60 does not become thin, and dielectric breakdown due to electric field concentration of the piezoelectric film 70 near the end of the piezoelectric active part 320 is formed. be able to.

In the present embodiment, the tapered portion 66 is formed as an inclined surface whose thickness is gradually reduced. However, the present invention is not limited to this. For example, as shown in FIG. like,
The film thickness gradually decreasing portion 66A may be configured such that the film thickness is intermittently reduced so that the cross section has a substantially stepped shape. The method of forming such a thinned portion 66A is not particularly limited. For example, a resist is applied on the lower electrode film 60 a plurality of times to form a region which becomes the thinned portion 66A of the lower electrode film 60. After forming a resist film having a step-like shape substantially the same as the tapered portion 66A, the lower electrode film 60 can be formed by patterning.

For example, as shown in FIG. 31 (b), the cross section may be a tapered portion 66B having an inclined curved surface. There is no particular limitation on the method of forming such a thinned portion 66B. For example, a region on the elastic film 50 where the lower electrode film 60 is not formed and a region to be the thinned portion 66B are covered with a mask. The lower electrode film 60 is formed by vapor deposition. That is, the lower electrode film 6
0 is formed in a part of the area covered by the mask so as to extend from the gap of the mask and has a gradually decreasing thickness 66 having a cross-sectionally curved surface.
B. Further, as described above, after forming a resist film having substantially the same shape as the gradually decreasing thickness portion 66B on the lower electrode film 60, as described above,
The lower electrode film 60 can be formed by patterning.

(Embodiment 17) FIG.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

This embodiment is an example in which an insulating film made of an insulating material is provided outside the lower electrode film 60 in the longitudinal direction. That is, in the present embodiment, as shown in FIG. 32, the piezoelectric active portion 32 including the lower electrode film 60, the piezoelectric film 70, and the upper electrode film 80 is formed on the elastic film 50 in a region facing the pressure generating chamber 12.
0 is formed outside the end of the lower electrode film 60 which is a boundary between the piezoelectric active portion 320 and the piezoelectric non-active portion 330. Is formed. The material of the insulating film 55 is not particularly limited, and may be, for example, an insulating material different from that of the elastic film 50.

In this embodiment, after patterning the lower electrode film 60, an insulating film 55 is formed outside one end in the longitudinal direction, and a piezoelectric film 70 and an upper electrode film 80 are formed and patterned on the insulating film 55. Thus, the piezoelectric active part 320 and the piezoelectric non-active part 330 are formed. Accordingly, the thickness of the piezoelectric film 70 does not become thin at the end of the lower electrode film 60, and dielectric breakdown due to electric field concentration of the piezoelectric film 70 at this portion can be prevented. Further, even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

(Embodiment 18) FIG. 33 shows Embodiment 18 of the present invention.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 33, instead of the insulating film 55, the outer portion of the lower electrode film 60, which is the boundary between the piezoelectric active portion 320 and the piezoelectric non-active portion 330, is provided. The thickness of the elastic film 50 is thicker than other portions, for example,
This embodiment is the same as the seventeenth embodiment except that a thick film portion 50a thicker than the thickness of the lower electrode film 60 is provided.

In the present embodiment, after the elastic film 50 is patterned to form the thick film portion 50a at a predetermined position, the piezoelectric film 70 and the upper electrode film 80 are formed and patterned to form the piezoelectric active portion 320 and The piezoelectric inactive portion 330 is formed. As a result, the thickness of the piezoelectric film 70 in a region corresponding to the end of the lower electrode film 60 does not become thinner than other portions, and dielectric breakdown due to electric field concentration of the piezoelectric film 70 in this portion is formed. can do. Also, in such a configuration, the same effect as in the above-described embodiment can be obtained.

(Embodiment 19) FIG. 34 shows Embodiment 19 of the present invention.
1A and 1B are a plan view and a sectional view of a main part of an ink jet recording head according to the first embodiment.

In the present embodiment, as shown in FIG. 34, the end of the upper electrode film 80 is formed inside the end of the lower electrode film 60. It is the end of the body active part 320. Further, for example, in the present embodiment, the end of the piezoelectric film 70 is located at substantially the same position as the end of the lower electrode film 60 and also on the lower electrode film 60 protruding outward from the end of the upper electrode film 80. The piezoelectric film 70 is formed, and this portion serves as a piezoelectric non-active portion 330 that is not substantially driven.

In the present embodiment, the lower electrode film removing portion 340 between the lower electrode film 60 and the lower electrode film 61 for wiring, in which the lower electrode film 60 is removed, has a piezoelectric film in this embodiment. 7
0 remains without being removed, and the lower electrode film 60 and the lead electrode 100 are insulated.

As described above, in the present embodiment, the piezoelectric active portion 320 is provided on the outer side of the end of the lead electrode 100 on the lead-out side.
For example, by removing the upper electrode film 80, the piezoelectric inactive portion 330 is continuously provided. Thus, the distance between the end of the upper electrode film 80, which is the end of the piezoelectric active portion 320, and the end of the lower electrode film 60 can be increased. Therefore, even when a voltage is applied to the piezoelectric body active portion 320, the electric field strength at the end of the piezoelectric body active portion 320 does not increase, and dielectric breakdown of the piezoelectric film 70 can be prevented. Further, since the thickness of the piezoelectric film 70 of the piezoelectric active portion 320 becomes uniform, the piezoelectric characteristics are improved. Note that, with such a configuration, the same effect as in the above-described embodiment can be obtained.

(Other Embodiments) The embodiments of the present invention have been described above, but the basic structure of the ink jet recording head is not limited to the above.

For example, in each of the embodiments described above, the end of the lower electrode film 60 is used as the end of the piezoelectric active portion 320, and the piezoelectric film 70 and the upper electrode film 80 thereover are extended to the outside. And the piezoelectric inactive portion 330 is provided.
0 is prevented, but the other end is an end of the piezoelectric active portion 320 by patterning the piezoelectric film 70 and the upper electrode film 80 in the pressure generating chamber 12. . Such an end portion corresponds to the piezoelectric film 70 and the upper electrode film 80.
The piezoelectric active portion 320 may be fixed by, for example, an adhesive or covered with a discontinuous piezoelectric film that is discontinuous with the piezoelectric film 70 of the piezoelectric element 300. May be protected to improve durability.

For example, in addition to the sealing plate 20 described above,
The common ink chamber forming substrate 30 may be made of glass ceramic, and further, the thin film 41 may be made of glass ceramic as a separate member, and the material, structure, and the like can be freely changed.

In the above-described embodiment, the nozzle openings are formed on the end surface of the flow path forming substrate 10. However, the nozzle openings may be formed so as to project in a direction perpendicular to the surface.

FIG. 35 is an exploded perspective view of the embodiment configured as described above, and FIG. 36 is a cross-sectional view of the flow path thereof. In this embodiment, the nozzle opening 11 is formed in the nozzle substrate 120 opposite to the piezoelectric element, and the nozzle communication port 22 that connects the nozzle opening 11 and the pressure generating chamber 12 is formed with the sealing plate 20 and the common ink chamber. It is arranged so as to penetrate the formation substrate 30, the thin plate 41A, and the ink chamber side plate 40A.

In this embodiment, the thin plate 41
A is basically the same as the above-described embodiment except that the ink chamber side plate 40A and the ink chamber side plate 40A are separate members, and the opening is formed in the ink chamber side plate 40A. Is omitted.

Here, also in this embodiment, similarly to the above-described embodiment, since the voltage can be applied to the piezoelectric active portion without passing through the contact hole, the displacement efficiency of the elastic film can be improved. it can.

Of course, it goes without saying that the above-described embodiments can be further combined with each other to achieve further effects.

In each of the embodiments described above, a thin-film type ink jet recording head which can be manufactured by applying a film forming and lithography process is described as an example.
Of course, the present invention is not limited to this. For example, a structure in which substrates are laminated to form a pressure generating chamber, or a structure in which a green sheet is attached or a piezoelectric film is formed by screen printing, or a crystal formed by a hydrothermal method or the like The present invention can be applied to ink jet recording heads of various structures, such as those that form a piezoelectric film by growth.

As described above, the present invention can be applied to ink-jet recording heads having various structures, as long as the gist of the present invention is not contradicted.

The ink jet recording head of each of the embodiments constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge and the like, and is mounted on an ink jet recording apparatus. FIG.
FIG. 2 is a schematic diagram illustrating an example of the ink jet recording apparatus.

As shown in FIG. 37, the recording head units 1A and 1B having the ink jet recording heads
Cartridges 2A and 2B constituting ink supply means are detachably provided. A carriage 3 on which the recording head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. I have. The recording head units 1A and 1B are, for example,
Each of them ejects a black ink composition and a color ink composition.

Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears (not shown) and the timing belt 7, so that the carriage 3 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. Moved. On the other hand, the apparatus main body 4 is provided with a platen 8 along the carriage 3. The platen 8 can be rotated by a driving force of a paper feed motor (not shown), and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller, is wound around the platen 8 and conveyed. It has become so.

[0253]

As described above, according to the present invention,
Continuously from the piezoelectric active portion, by providing a piezoelectric non-active portion having a piezoelectric film but not substantially driven, it is possible to apply a voltage to the piezoelectric active portion without forming a contact hole, Since the piezoelectric active portion can be provided in a region facing the pressure generating chamber, displacement characteristics and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink jet recording head according to a first embodiment of the present invention.

FIG. 2 is a plan view and a cross-sectional view of the inkjet recording head according to the first embodiment of the present invention, showing the same.

FIG. 3 is a perspective view showing a modification of the sealing plate of FIG. 1;

FIG. 4 is a cross-sectional view illustrating a thin-film manufacturing process according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a thin-film manufacturing process according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a thin-film manufacturing process according to the first embodiment of the present invention.

FIGS. 7A and 7B are a plan view and a cross-sectional view illustrating a main part of the inkjet recording head according to the first embodiment of the invention.

FIG. 8 is a plan view showing a modified example of the ink jet recording head according to the first embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a main part of an ink jet recording head according to a second embodiment of the invention.

FIG. 10 is a cross-sectional view illustrating a modification of the ink jet recording head according to Embodiment 2 of the present invention.

FIG. 11 is a plan view showing a modification of the ink jet recording head according to the second embodiment of the present invention.

12A and 12B are a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to Embodiment 3 of the present invention.

FIG. 13 is a plan view showing a modification of the ink jet recording head according to Embodiment 3 of the present invention.

FIG. 14 is a plan view showing a main part of an ink jet recording head according to Embodiment 4 of the present invention.

15A and 15B are a plan view and a cross-sectional view illustrating a modified example of the ink jet recording head according to Embodiment 4 of the present invention.

FIG. 16 is a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to a fifth embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a step of manufacturing the ink jet recording head according to Embodiment 5 of the present invention.

FIG. 18 is a plan view illustrating a main part of an ink jet recording head according to a sixth embodiment of the invention.

FIG. 19 is a plan view showing a main part of an ink jet recording head according to Embodiment 7 of the present invention.

FIG. 20 is a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to Embodiment 8 of the present invention.

FIGS. 21A and 21B are a plan view and a sectional view showing a main part of an ink jet recording head according to Embodiment 9 of the present invention.

FIG. 22 is a plan view showing a main part of an ink jet recording head according to Embodiment 10 of the present invention.

FIG. 23 is a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to Embodiment 11 of the present invention.

FIG. 24 is a plan view showing a modification of the ink jet recording head according to Embodiment 11 of the present invention.

FIG. 25 is a plan view showing a modification of the ink jet recording head according to Embodiment 11 of the present invention.

FIG. 26 is a plan view showing a main part of an ink jet recording head according to Embodiment 12 of the present invention.

FIG. 27 is a plan view showing a main part of an ink jet recording head according to Embodiment 13 of the present invention.

FIG. 28 is a plan view and a cross-sectional view illustrating a main part of an inkjet recording head according to Embodiment 14 of the present invention.

FIG. 29 is a plan view showing a main part of an ink jet recording head according to Embodiment 15 of the present invention.

30A and 30B are a plan view and a cross-sectional view illustrating a main part of an ink jet recording head according to Embodiment 16 of the invention.

FIG. 31 is a sectional view showing a modification of the ink jet recording head according to Embodiment 16 of the present invention.

FIGS. 32A and 32B are a plan view and a cross-sectional view illustrating a main part of an ink jet recording head according to Embodiment 17 of the invention.

FIG. 33 is a plan view and a cross-sectional view showing a main part of an inkjet recording head according to Embodiment 18 of the present invention.

34A and 34B are a plan view and a cross-sectional view illustrating a main part of an ink jet recording head according to Embodiment 19 of the invention.

FIG. 35 is an exploded perspective view of an ink jet recording head according to another embodiment of the present invention.

FIG. 36 is a sectional view showing an ink jet recording head according to another embodiment of the present invention.

FIG. 37 is a schematic view of an ink jet recording apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 flow path forming substrate 11 nozzle opening 12 pressure generating chamber 50 elastic film 60 lower electrode film 70 piezoelectric film 80 upper electrode film 300 piezoelectric element 320 piezoelectric active portion 330 piezoelectric non-active portion

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Soichi Moriya 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (56) References JP-A-9-286103 (JP, A) 8-127124 (JP, A) JP-A-10-181016 (JP, A) JP-A-9-239891 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16 B32B 7/02

Claims (56)

(57) [Claims] 1. A pressure generating chamber communicating with a nozzle opening, a lower electrode provided in a region corresponding to the pressure generating chamber via an insulating layer, a piezoelectric layer provided on the lower electrode, and the piezoelectric body An ink jet recording head comprising: a piezoelectric element comprising an upper electrode provided on the surface of a layer; wherein the piezoelectric element is provided in a region facing the pressure generating chamber.
From the piezoelectric active part to be a qualitative driving part and the piezoelectric active part
Having a continuous piezoelectric layer but not substantially driven
An ink jet recording head having a piezoelectric non-active portion, and wherein the piezoelectric layer has a crystal oriented preferentially. 2. The ink jet recording head according to claim 1, wherein the piezoelectric layer has a columnar crystal. 3. The ink jet recording head according to claim 1, wherein the piezoelectric inactive portion extends from an area facing the pressure generating chamber to an area outside the pressure generating chamber. 4. The piezoelectric inactive section according to claim 1, wherein the piezoelectric inactive portion is formed by removing the lower electrode, and is connected to the upper electrode or the upper electrode via the piezoelectric inactive portion. An ink-jet recording head, wherein the lead electrode extends to the peripheral wall of the pressure generating chamber. 5. The piezoelectric element according to claim 1, wherein an end of the upper electrode is located inside an end of the lower electrode and serves as an end of the piezoelectric active portion. The piezoelectric layer is provided on the lower electrode protruding outside from the end of the electrode to constitute the piezoelectric inactive portion, and the piezoelectric layer is provided outside the end of the lower electrode. An ink jet recording head characterized in that: 6. An ink jet recording head according to claim 1, wherein said piezoelectric non-active portion is continuously provided at one longitudinal end of said piezoelectric active portion. . 7. The piezoelectric active portion according to claim 6, wherein a width of at least a portion of the non-active portion of the piezoelectric body crossing a boundary between an end of the pressure generating chamber and a peripheral wall is smaller than a width of the active portion of the piezoelectric body. An ink jet recording head, characterized in that: 8. The pressure generating chamber according to claim 6, wherein a width of at least a portion of the piezoelectric inactive portion which crosses a boundary between an end of the pressure generating chamber and a peripheral wall is larger than a width of the pressure generating chamber. An ink jet recording head characterized by the following. 9. The displacement suppressing layer according to claim 1, wherein a displacement suppressing layer for suppressing displacement of the piezoelectric active portion is provided in a region facing a boundary between the piezoelectric active portion and the piezoelectric non-active portion. An ink jet recording head, comprising: 10. The pressure sensor according to claim 1, wherein the lower electrode is provided continuously up to the partition wall on both sides in the width direction of the pressure generating chamber and a region facing the adjacent pressure generating chamber. An ink jet recording head characterized by the following. 11. The piezoelectric device according to claim 1, wherein the lower electrode is provided such that both ends in the width direction are located in the pressure generating chamber together with both ends in the width direction of the piezoelectric layer. An ink jet recording head, which extends from the other end of the pressure generating chamber opposite to the one end in the longitudinal direction where the body non-active portion is provided to the peripheral wall of the pressure generating chamber. 12. An ink jet recording head according to claim 1, wherein a region other than said piezoelectric inactive portion facing said pressure generating chamber is covered by said lower electrode. 13. The ink-jet apparatus according to claim 3, wherein a width of the lower electrode below the piezoelectric inactive portion is smaller than a width of the pressure generating chamber. Type recording head. 14. The method according to claim 12, wherein the piezoelectric inactive portion extends from a substantially central portion in a longitudinal direction of the pressure generating chamber on at least one peripheral wall in a width direction of the pressure generating chamber. Characteristic inkjet recording head. 15. The method according to claim 12, wherein
An ink jet recording head, wherein a portion below the piezoelectric non-active portion from which the lower electrode is removed has a substantially circular shape. 16. In any one of claims 12 to 15,
An ink jet recording head, wherein a direction in which an edge of the upper electrode crosses from above the lower electrode to above the lower electrode removing portion does not coincide with a direction in which the upper electrode extends on a peripheral wall. 17. The width of the lower electrode in a portion of the piezoelectric active portion facing the vicinity of an end of the piezoelectric active portion on the side of the piezoelectric non-active portion, the width of the lower electrode being larger than the width of the other portion. An ink jet recording head having a narrow width. 18. The ink jet recording head according to claim 17, wherein the width of at least the front end of the narrow portion of the lower electrode is smaller than the width of the piezoelectric layer and the upper electrode of the piezoelectric non-active portion. . 19. The ink jet recording head according to claim 17, wherein the entire width of the narrow portion of the lower electrode is smaller than the piezoelectric layer of the piezoelectric non-active portion and the upper electrode. 20. The method according to claim 17, wherein the width of the narrow portion of the lower electrode is wider than the width of the piezoelectric layer and the upper electrode of the non-piezoelectric active portion, and the width direction end face of the narrow portion and the width of the lower electrode are different. An ink jet recording head, wherein the distance from the widthwise end surface of the upper electrode is 10 μm or less. 21. The piezoelectric element according to claim 3, wherein the lower electrode is discontinuous below the piezoelectric layer in a region opposed to a boundary between the pressure generating chamber and the peripheral wall. An ink jet recording head comprising a lower electrode. 22. The ink jet recording head according to claim 21, wherein the discontinuous lower electrode is provided so as to cover at least an edge of the pressure generating chamber. 23. The lower electrode according to claim 21, wherein the discontinuous lower electrode is provided near a longitudinal end of the pressure generating chamber of the lower electrode and extends in a direction in which the pressure generating chambers are juxtaposed. An ink jet recording head characterized in that some portions are discontinuous with the lower electrode. 24. The method according to claim 21, wherein
The inkjet recording head according to claim 1, wherein the discontinuous lower electrode is not electrically connected to any of the electrodes. 25. In any one of claims 21 to 23,
The inkjet recording head according to claim 1, wherein the discontinuous lower electrode is connected to a resistor such that a charging time constant is larger than a driving pulse. 26. In any one of claims 21 to 25,
On the peripheral wall of the discontinuous lower electrode opposite to the lower electrode, a wiring lower electrode that is discontinuous with the discontinuous lower electrode and has one end connected to an external wiring is provided for each of the piezoelectric elements. An ink jet recording head, which is provided. 27. The method according to claim 21, wherein
The discontinuous lower electrode is separated for each of the piezoelectric active portions in the width direction of the pressure generating chamber, and is connected to the upper electrode of each of the piezoelectric active portions or a lead electrode connected thereto. An ink jet recording head characterized in that: 28. The ink jet recording head according to claim 27, wherein each of the discontinuous lower electrodes and the lower electrodes have an interval capable of being insulated. 29. The ink jet recording head according to claim 27, wherein an intermediate electrode connected to none of the discontinuous lower electrodes is connected between the adjacent lower electrodes. 30. The method according to claim 21, wherein
An ink jet recording head, wherein the piezoelectric layer is left in at least a part of the lower electrode film removed part other than a region corresponding to the piezoelectric element. 31. The method according to claim 1, wherein a residual portion made of the same layer as the lower electrode is provided on the partition walls on both sides in the width direction of the pressure generating chamber. Inkjet recording head. 32. The piezoelectric active section according to claim 31, further comprising a discontinuous lower electrode provided outside the end of the lower electrode of the piezoelectric active section, the discontinuous lower electrode being discontinuous from the lower electrode. An ink jet recording head continuously extending from a lower electrode. 33. An ink jet recording head according to claim 31, wherein said remaining portion is provided continuously with said lower electrode constituting said piezoelectric element. 34. In any one of claims 31 to 33,
An ink jet recording head, wherein a distance between a width direction end face of the lower electrode and a width direction end face of the remaining portion is wider than a thickness of the piezoelectric layer and smaller than a width of the lower electrode. 35. In any one of claims 31 to 34,
A longitudinal end of the piezoelectric layer exists near an end of the pressure generating chamber in which the lower electrode extends to the peripheral wall, and the lower electrode extending outward from the end becomes wider. An ink-jet recording head, wherein the distance to the lower electrode is larger than the thickness of the piezoelectric layer and smaller than the width of the lower electrode. 36. In any one of claims 31 to 35,
The width of the remaining portion is 50% or more of the width of the partition wall between the adjacent pressure generating chambers. 37. In any one of claims 31 to 36,
The lower electrode and the residual portion are located in a region corresponding to the plurality of pressure generating chambers arranged in parallel and the partition walls on both sides in the width direction thereof.
An ink jet recording head formed in a region having a width of 0% or more. 38. In any one of claims 31 to 37,
An ink jet recording head according to claim 1, wherein said lower electrode and said remaining portion are formed in a region of 50% or more of the entire area of the flow path forming substrate in which said pressure generating chamber is formed. 39. The ink jet recording head according to claim 1, wherein the crystal structure of the piezoelectric layer is substantially the same as the crystal structure on the lower electrode and on the insulating layer. 40. The ink jet recording head according to claim 39, wherein a crystal seed serving as a nucleus of a crystal of the piezoelectric layer is formed on a surface of the insulating layer. 41. The ink jet recording head according to claim 40, wherein the crystal seeds are formed in an island shape. 42. The ink jet recording head according to claim 3, wherein a second insulating layer is provided outside an end of the lower electrode. 43. An ink jet recording head according to claim 42, wherein said second insulating layer has substantially the same thickness as said lower electrode. 44. The ink jet recording head according to claim 42, wherein the second insulating layer is made of an insulating material different from the insulating layer. 45. The ink jet recording head according to claim 3, wherein a thick film portion is provided on the insulating layer outside an end of the lower electrode. 46. The ink jet recording head according to claim 45, wherein the thick film portion has substantially the same film thickness as the lower electrode. 47. The thin film taper according to claim 3, wherein an end portion of the lower electrode is provided with a tapered portion in which the thickness of the lower electrode is gradually reduced toward the outside of the piezoelectric active portion. An ink jet recording head characterized by being used. 48. The ink jet recording head according to claim 47, wherein the tapered portion has an inclined surface in which the film thickness of the lower electrode is gradually reduced. 49. The ink jet recording head according to claim 47, wherein the thickness of the lower electrode is gradually reduced in a stepwise manner in the tapered portion. 50. The ink jet recording head according to claim 47, wherein the tapered portion has an inclined curved surface in which the thickness of the lower electrode is gradually reduced. 51. The method according to claim 47, wherein
The thickness of the piezoelectric layer formed on the tapered portion,
An ink jet recording head characterized in that it is thicker than other portions. 52. An ink jet recording head according to claim 6, wherein a structure near the one end of the piezoelectric active portion is also provided on the other end side. 53. The piezoelectric active part according to claim 6, wherein the other end of the piezoelectric active part is formed by an end of the piezoelectric layer and the upper electrode, and the other end of the piezoelectric active part is provided. Is covered by a discontinuous piezoelectric layer that is discontinuous from the piezoelectric layer. 54. The piezoelectric active part according to claim 6, wherein the other end of the piezoelectric active part is formed by an end of the piezoelectric layer and the upper electrode, and the other end of the piezoelectric active part is provided. Is an ink jet recording head fixed by an adhesive. 55. The pressure generating chamber according to claim 1, wherein the pressure generating chamber is formed on a silicon single crystal substrate by anisotropic etching, and each of the lower electrode, the piezoelectric layer, and the upper electrode is formed by film formation and lithography. An ink jet recording head formed by a method. 56. An ink jet recording apparatus comprising the ink jet recording head according to any one of claims 1 to 55.