JP2012076449A - Droplet discharge head, ink cartridge, image forming apparatus, and method of manufacturing the droplet discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variations in discharge characteristics by enhancing rigidity of a fixed end portion of a vibration plate.SOLUTION: The droplet discharge head includes: a nozzle plate having a plurality of nozzle holes for discharging droplets; a vibration plate that vibrates; a partition wall provided between the nozzle plate and the vibration plate to partition a discharge chamber formed in conformation to each of the nozzle holes; and a pressure generation means which displaces and deforms, for each discharge chamber, the vibration plate to generate a pressure for pressurizing liquid in the discharge chamber. A laminated film is provided in an area facing the partition wall on the side opposite to the side provided with the partition wall of the vibration plate to enhance the rigidity of the vibration plate along the partition wall. The width of the laminated film is larger than the width of the partition wall.

Description

  The present invention relates to a droplet discharge head, an ink cartridge, an image forming apparatus, and a method for manufacturing a droplet discharge head.

  An inkjet recording apparatus used as an image forming apparatus (image recording apparatus) such as a printer, a facsimile machine, a copying apparatus, etc. has an extremely low noise during recording, can perform high-speed printing, has a high degree of freedom in ink, and is inexpensive. It has many advantages such as the ability to use paper. Among these, the ink-on-demand system that ejects ink droplets only when recording is required does not require collection of ink droplets that are not necessary for recording, and is now mainstream.

  Such an ink jet recording apparatus adds a nozzle that discharges ink droplets, a discharge chamber (also referred to as a pressurized liquid chamber, a pressure chamber, an ink flow path, and the like) that communicates with the nozzle, and ink in the discharge chamber. A droplet discharge head including pressure generating means for generating pressure to be pressed is mounted. The droplet discharge head discharges ink droplets from the nozzles by pressurizing the ink liquid in the discharge chamber with the pressure generated by the pressure generating means.

  The droplet discharge head uses a piezoelectric type that discharges ink droplets by deforming and displacing the diaphragm forming the wall surface of the discharge chamber using an electromechanical transducer element such as a piezoelectric element as a pressure generating means, There is known a bubble type (thermal type) in which bubbles are generated by boiling an ink film using an electrothermal conversion element such as a heating resistor disposed in a room and ink droplets are ejected. In addition, the piezoelectric type includes a longitudinal mode, a lateral mode (bend mode) type, and a shear mode type using shear deformation. Among them, in recent years, with the advance of semiconductor processes and micromachining technology, patterning technology has been established, and the configuration of an actuator that directly forms a discharge chamber and a piezoelectric element on a low-cost Si substrate has been studied.

  Here, among the above-described piezo-type droplet discharge heads, for example, in a lateral vibration (bend mode) type actuator formed by sequentially laminating a lower electrode, a piezoelectric material, and an upper electrode on a vibration plate, The diaphragm is less rigid than the other surfaces constituting the discharge chamber (large structural compliance). In addition, since the formation of ink droplets in the droplet discharge head using a diaphragm is due to the displacement of the diaphragm, the variation in the width of the diaphragm that affects the displacement of the diaphragm is an important factor that affects the ejection characteristics. It becomes. The variation in the width of the diaphragm is caused by the variation in the width of the discharge chamber when the discharge chamber is formed.

  Therefore, conventionally, since the processing accuracy of the pressure chamber is poor due to processing with a depth, a method of reducing the variation in the width of the diaphragm using a thin film material with high processing accuracy as a sacrificial layer is known (for example, , See Patent Document 1). Further, conventionally, a method is known in which a thick part and a thin part are formed on the diaphragm to ensure the rigidity of the diaphragm (for example, see Patent Document 2).

  Furthermore, a protective film is provided on the piezoelectric element formed on the diaphragm from the vicinity of the opposing region of the partition wall that partitions the pressure generating chamber, and the thickness of the protective film on the upper surface of the piezoelectric element is made thinner than the film thickness on the diaphragm. There are known methods for improving ejection characteristics and moisture resistance (see, for example, Patent Documents 3 and 4).

  However, in the method of Patent Document 1 described above, a recess after removing the sacrificial layer remains at the diaphragm end portion of the pressure chamber, and bubbles tend to accumulate in this space. For this reason, the ejection characteristics of the ink droplets are deteriorated by the bubbles in the pressure chamber. Further, in the method of Patent Document 2 described above, since the thick part and the thin part are formed on the diaphragm, the number of steps increases, and the cost may increase. Further, since the thick part of the diaphragm is joined to the drive means having high rigidity, the rigidity of the whole diaphragm is not affected by the shape of the fixed end part of the diaphragm.

  Further, in the methods of Patent Documents 3 and 4 described above, a protective film is provided on the piezoelectric element of the diaphragm and in the vicinity of the opposing area of the partition wall, and the piezoelectric element and the protective film are provided in the opposing area where the pressure generating chamber of the diaphragm is formed. Since the film is formed, the thickness of the facing region where the pressure generation chamber of the diaphragm is formed is thicker than the thickness of the region facing the partition wall of the diaphragm. Therefore, the variation in the processing of the pressure generation chamber described above affects the variation in the width of the diaphragm, and the discharge characteristics are affected.

  The present invention has been made in view of the above-described problems, and improves the rigidity of the fixed end of the diaphragm and reduces the variation in ejection characteristics, a droplet ejection head, an ink cartridge, an image forming apparatus, and a droplet ejection An object is to provide a method for manufacturing a head.

  In order to achieve the above object, the present invention provides a nozzle plate having a plurality of nozzle holes for discharging droplets, a vibration plate that can vibrate, and the nozzle hole between the nozzle plate and the vibration plate. Liquid droplet ejection comprising partition walls partitioning the ejection chambers formed corresponding to each, and pressure generating means for generating pressure for displacing and deforming the diaphragm to pressurize the liquid in the ejection chambers for each ejection chamber A laminated film that increases rigidity of the diaphragm along the partition wall in a region facing the partition wall on the opposite side of the diaphragm on the side where the partition wall is provided, and the width of the stacked film Is wider than the width of the partition wall.

  The present invention also provides an ink cartridge in which the above-described droplet discharge head and an ink tank that supplies ink to the droplet discharge head are integrated.

  According to another aspect of the present invention, there is provided an image forming apparatus including the above-described droplet discharge head.

  Further, the present invention provides a nozzle plate having a plurality of nozzle holes for discharging droplets, a vibrating plate capable of vibrating, and formed between the nozzle plate and the vibrating plate corresponding to each of the nozzle holes. A liquid for manufacturing a droplet discharge head, comprising: a partition wall that partitions the discharged discharge chamber; and a pressure generating means that generates a pressure to pressurize the liquid in the discharge chamber for each discharge chamber by displacing and deforming the diaphragm. In a method for manufacturing a droplet discharge head, a laminated film that increases rigidity of the diaphragm along the partition wall in a region facing the partition wall on a side opposite to the side on which the partition wall of the diaphragm is provided, It is characterized by comprising a laminated film forming step of forming wider than the width of the partition wall.

  According to the present invention, it is possible to increase the rigidity of the fixed end portion of the diaphragm and reduce the variation in discharge characteristics.

1 is an exploded perspective view of a droplet discharge head according to a first embodiment of the present invention. It is sectional drawing which cut | disconnected the droplet discharge head shown in FIG. 1 by XX '. It is an expanded sectional view of a droplet discharge head. It is a figure which shows the process of the manufacturing method of the droplet discharge head which concerns on 1st Embodiment of this invention. It is sectional drawing of the droplet discharge head which concerns on 2nd Embodiment of this invention. It is a figure which shows the process of the manufacturing method of the droplet discharge head which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the droplet discharge head which concerns on 3rd Embodiment of this invention. It is a schematic diagram at the time of seeing the liquid chamber board | substrate which concerns on 4th Embodiment of this invention from the protective substrate side. It is sectional drawing which cut | disconnected FIG. 8 along AA '. It is a figure which shows the process of the manufacturing method of the droplet discharge head which concerns on 4th Embodiment of this invention. It is sectional drawing which cut | disconnected FIG. 8 along BB '. It is sectional drawing which cut | disconnected FIG. 8 along CC '. It is a figure which shows the process of the manufacturing method of the droplet discharge head which concerns on 5th Embodiment of this invention. It is a perspective view of a head integrated ink cartridge concerning a 6th embodiment of the present invention. It is a perspective view of the inkjet recording device which concerns on 7th Embodiment of this invention. It is a side view of the inkjet recording device which concerns on 7th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

<First Embodiment: Droplet Discharge Head>
FIG. 1 is an exploded perspective view of a droplet discharge head according to the first embodiment of the present invention. A part of the droplet discharge head 1 is shown in a sectional view. The droplet discharge head 1 according to the first embodiment uses the actuator according to the present invention, and shows an example of a side shooter system that discharges ink droplets from nozzle holes provided on the surface of the substrate. It is.

  As shown in FIG. 1, the droplet discharge head 1 has a laminated structure in which three substrates, which are a nozzle substrate 10, a liquid chamber substrate 20, and a protective substrate 30, are stacked.

  The nozzle substrate 10 has a plurality of nozzle holes 11 for ejecting ink droplets. The liquid chamber substrate 20 is formed corresponding to the vibration plate 21 that can vibrate, the discharge holes 22 that store the ink liquid, the partition walls 23 that partition the discharge chambers 22, and the vibration plate 21. An actuator 24 serving as a pressure generating unit including a piezoelectric element that applies pressure to the ink liquid in the discharge chamber 22, a fluid resistance portion 25 communicating with the discharge chamber 22, and a common liquid chamber 26 are provided.

  The protective substrate 30 includes a protective space 31 that protects the actuator 24, a column 32 that supports the partition wall 23, and an ink supply hole 33.

  Next, the droplet discharge head 1 according to the first embodiment will be described more specifically with reference to FIG. FIG. 2 is a cross-sectional view of the droplet discharge head shown in FIG. 1 cut along XX ′. Here, only two discharge chambers are shown for convenience. FIG. 2 also shows ink droplets 12 and recording paper 13.

  As shown in FIG. 2, the vibration plate 21 is configured by a three-layered film including, for example, a silicon oxide film 21-1, a polysilicon 21-2, and a silicon oxide film 21-3. As will be described later, an SOI (Silicon on Insulator) substrate in which a silicon oxide film 21-1 and a polysilicon 21-2 are bonded to a silicon substrate is used as the silicon oxide film 21-1 and the polysilicon 21-2. Used.

  Further, the upper surface of the silicon oxide film 21-3 (the surface on the side of the protective substrate 30 shown in FIG. 2) is made of, for example, a platinum film that becomes a unimorph type thin film piezoelectric element that displaces and deforms the diaphragm 21 by piezoelectric displacement. A lower electrode 40, a piezoelectric material 41 made of PZT (lead zirconate titanate), and an upper electrode 42 made of a platinum film are formed.

  The actuator 24 as the pressure generating means has a multilayer structure formed on the diaphragm 21 as described above. The actuator 24 is formed in a region facing the discharge chamber 22. Further, the actuator 24 has a lower electrode 40 and an upper electrode so as to cover the side surfaces of the piezoelectric material 41 and the upper electrode 42 shown in FIG. 2 and the upper surface of the upper electrode 42 (the surface on the protective substrate 30 side shown in FIG. 2). An interlayer insulating film 43 disposed between the layers 42 and the wiring material and a passivation film 44 for protecting the wiring material are formed.

  Further, in the region (position) opposite to the partition wall 23 on the side opposite to the side where the partition wall 23 is provided with respect to the diaphragm 21, an interlayer insulation that is the same insulating film as the interlayer insulating film 43 is formed along the partition wall 23. A laminated film 47 including a film 45 and a passivation film 46 that is the same silicon nitride film as the passivation film 44 is formed. Here, the width of the laminated film 47 is formed wider than the width of the partition wall 23. For example, a silicon oxide film or the like may be used for the interlayer insulating film 45, and a silicon nitride film or the like may be used for the passivation film 46, for example.

  The nozzle substrate 10 shown in FIG. 2 is a nickel substrate formed by, for example, a nickel high-speed electroforming method, and has a thickness of about 30 [μm]. A nozzle hole 11 communicating with the discharge chamber 22 is formed in the surface portion of the nozzle substrate 10. The protective substrate 30 is formed with a protective space 31 for protecting the actuator 24 including the piezoelectric element and preventing displacement, and a pillar 32 for supporting the partition wall 23 in order to increase the rigidity of the partition wall 23.

<Operation of Droplet Discharge Head 1>
Next, the operation of the droplet discharge head 1 configured as shown in FIGS. 1 and 2 will be described. The ink liquid is supplied into each discharge chamber 22 from the ink supply hole 33 via the common liquid chamber 26. A pulse voltage having a predetermined pulse width is applied between the lower electrode 40 and the upper electrode 42 of the piezoelectric element in a state where the discharge chamber 22 is filled with ink.

  As a result, the piezoelectric element that is deformed in the transverse vibration mode contracts, and the entire diaphragm 21 that is in close contact with the piezoelectric element is deformed into a convex shape toward the discharge chamber 22. The volume in the discharge chamber 22 decreases and the pressure in the discharge chamber 22 rapidly increases, so that the ink droplets 12 are discharged from the nozzle holes 11 toward the recording paper 13. As described above, by continuously applying the pulse voltage in accordance with the pressure fluctuation period in the discharge chamber 22, it is possible to discharge the ink droplets 12 continuously from the nozzle holes 11.

<Laminated film 47 provided in the area opposite to the partition wall 23>
Next, the laminated film 47 provided in the area | region facing the partition 23 of the diaphragm 21 is demonstrated using FIG. FIG. 3 shows an enlarged cross-sectional view of the droplet discharge head. 3A shows an enlarged cross-sectional view of a conventional droplet discharge head, and FIG. 3B shows an enlarged cross-sectional view of the droplet discharge head according to the first embodiment.

  The discharge chamber 22 shown in FIGS. 3A and 3B is formed by a process of etching a silicon substrate at a depth of about 50 to 100 [μm] as will be described later. In this step, the variation in the pattern width becomes very large, so that the width of the discharge chamber 22 partitioned by the partition wall 23 varies.

  For example, in the conventional diaphragm 21 shown in FIG. 3A, the width of the discharge chamber 22 is the width L of the diaphragm 21. Therefore, as described above, when the width of the discharge chamber 22 varies, the width L of the diaphragm 21 varies. Further, the variation in the width L of the diaphragm 21 causes the rigidity of the diaphragm 21 to vary.

  On the other hand, in the first embodiment shown in FIG. 3B, the diaphragm 21 is disposed along the partition wall 23 in a region facing the partition wall 23 on the side opposite to the side where the partition wall 23 of the diaphragm 21 is provided. An interlayer insulating film 45 and a passivation film 46 are formed as a laminated film 47 that increases rigidity. Further, the width Ws of the laminated film 47 is wider than the width Wc of the partition wall 23.

  Therefore, in the first embodiment, the fixed end portion of the diaphragm 21 is determined (defined) by the laminated film 47. That is, the width M of the diaphragm 21 is determined (defined) by the width Ws of the laminated film 47 formed at the fixed end of the diaphragm 21. Further, the rigidity of the fixed end portion of the diaphragm 21 can be increased by the width Ws of the laminated film 47. The laminated film 47 may include any one or both of the interlayer insulating film 45 and the passivation film 46.

  In the first embodiment, the width of the low-rigidity portion of the vibration plate 21 is reduced by patterning the thin film material of the laminated film 47 with higher accuracy (small variation) than the variation in pattern width in the process of forming the discharge chamber 22. It becomes possible to decide (normative). As a result, in the first embodiment, the rigidity of the diaphragm 21 is less affected by variations in the width of the discharge chamber 22 than in FIG. 3A, and the discharge characteristics when ink droplets are discharged are stabilized. Can be achieved.

  If the insulating film used for the laminated film 47 is a film having a high Young's modulus, a thinner film has the effect of increasing the rigidity of the diaphragm fixed end. Therefore, the laminated film 47 is made of, for example, a highly rigid alumina film, SiC or Ir. If a conductive film such as Ta is used, a higher effect can be obtained.

<Method for Manufacturing Droplet Discharge Head 1>
Next, a manufacturing method of the droplet discharge head according to the first embodiment will be described with reference to FIG. FIG. 4 shows steps of a method for manufacturing a droplet discharge head according to the first embodiment of the present invention. In the first embodiment, an actuator is created by depositing a diaphragm material and a piezoelectric element material on a silicon substrate 110.

As shown in FIG. 4A, a silicon oxide film 21-1 made of silicon oxide (SiO ₂ ) as an insulating film is formed on one surface of a <100> silicon substrate 110 having a thickness of about 400 [μm]. An SOI substrate in which about 0.2 [μm] and about 2.0 [μm] of polysilicon 21-2 which is a material for forming the diaphragm 21 are used is used. A silicon oxide film 27 is formed on the opposite surface of the silicon substrate 110.

Next, by forming a silicon oxide film 21-3 of about 0.3 [μm] made of silicon oxide (SiO ₂ ) on the surface of the SOI substrate by a pyro oxidation method, the diaphragm 21 is formed. Form.

  Next, as shown in FIG. 4B, a platinum (Pt) layer to be the lower electrode 40 of the piezoelectric element is formed on the silicon oxide film 21-3 by sputtering to a thickness of about 0.2 [μm]. Further, a piezoelectric material 41 made of lead zirconate titanate (PZT) is formed by sputtering to a thickness of about 2 [μm], and a platinum (Pt) layer serving as the upper electrode 42 is formed thereon by sputtering to a thickness of about 0.1 [μm]. μm] is formed.

  Next, as shown in FIG. 4C, the upper electrode 42 and the piezoelectric material 41 are patterned by a lithoetch method. Thereby, a piezoelectric element is formed in a region facing the discharge chamber 22 of the vibration plate 21. Next, an insulating film to be an interlayer insulating film 43 is formed by plasma CVD so as to cover the lower electrode 40, the patterned piezoelectric material 41, and the upper electrode 42, and wiring contact is formed by lithoetching. A via hole is formed for removing the hole.

  Next, after forming a wiring pattern made of an aluminum material, as shown in FIG. 4D, a silicon nitride film, for example, serving as a passivation film 44 for protecting the aluminum wiring is formed on the insulating film to be the interlayer insulating film 43 by plasma CVD. About 0.8 [μm] is formed by the method. Thereafter, the insulating film and the silicon nitride film formed between the portion where the actuator 24 is formed simultaneously with the pad opening and the opposing region of the diaphragm 21 where the partition wall 23 is formed are removed by a lithoetch method.

  As a result, the interlayer insulating film 43 and the passivation film 44 that cover the piezoelectric material 41 and the upper electrode 42 are formed in the portion where the actuator 24 is formed. A laminated film 47 including an interlayer insulating film 45 and a passivation film 46 for increasing the rigidity of the diaphragm 21 is formed in a facing region of the diaphragm 23 on the side opposite to the side where the partition wall 23 of the diaphragm 21 is formed.

  Next, as shown in FIG. 4E, recesses to be the discharge chamber 22, the fluid resistance portion 25, and the common liquid chamber 26 are formed on the opposite surface of the silicon substrate 110 by ICP dry etching. Thereby, the liquid chamber substrate 20 on which the actuator 24 and the laminated film 47 are formed is completed.

  Note that, as described above, the discharge chamber 22 formed by etching the silicon substrate 110 to a depth of about 50 to 100 [μm] has a very large dimensional variation, and thus the width of the discharge chamber 22 vibrates. In the structure having the width of the plate 21, the variation in the width of the discharge chamber 22 becomes the variation in the width of the vibration plate 21, and the variation in the width of the vibration plate 21 causes the variation in the rigidity of the vibration plate 21. However, in the first embodiment, the laminated film 47 including the interlayer insulating film 45 and the passivation film 46 is formed in a region facing the partition wall 23 with the vibration plate 21 interposed therebetween. The laminated film 47 is formed to have a width wider than that of the partition wall 23.

  In this way, a thin film with high dimensional controllability is formed at the end of the diaphragm 21 so as to protrude beyond the partition wall 23 toward the discharge chambers 22 on both sides, thereby varying the width of the discharge chamber 22. Even if this occurs, a structure in which the rigidity of the diaphragm 21 does not easily change can be achieved.

  Next, as shown in FIG. 4F, the nozzle substrate 10 manufactured by high-speed electroforming with a sulfamic acid bath is bonded to the discharge chamber 22 side of the liquid chamber substrate 20.

  Finally, as shown in FIG. 4G, a protective substrate 30 in which a concave protective space 31 is separately formed using a silicon substrate 110 by a litho-etching method is connected to the side on which the piezoelectric element of the liquid chamber substrate 20 is formed. Adhere to the surface. Further, the aluminum wiring portion connected to the upper electrode 42 and the lower electrode 40 of the piezoelectric element is connected to the drive circuit. Thereby, the droplet discharge head 1 according to the first embodiment is completed.

  The protective substrate 30 may be a <110> silicon substrate 110 processed by wet etching using an alkaline etching solution such as TMAH or KOH, or may be a substrate in which grooves are formed on a glass substrate by blasting. Further, the protective substrate 30 may be a molded part such as a resin mold or a metal injection mold.

  Further, when the drive circuit is integrally formed on the liquid chamber substrate 20 on which the actuator 24 is formed, the silicon oxide film formed by the pyro oxidation method described above is formed by the LOCOS oxidation method, and a region for forming the silicon oxide film is selected. Thus, the drive circuit can be formed over the same substrate.

  As described above, according to the first embodiment, it is possible to increase the rigidity of the fixed end portion of the diaphragm and reduce variations in discharge characteristics.

<Second Embodiment: Droplet Discharge Head>
Next, a liquid droplet ejection head according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 shows a cross-sectional view of a liquid droplet ejection head according to the second embodiment of the present invention.
The second embodiment is different from the first embodiment in the configuration of the laminated film 47 laminated in the region facing the partition wall 23 of the diaphragm 21. In the second embodiment, the laminated film 47 further includes a piezoelectric element. In addition, about another part, description is abbreviate | omitted using the same code | symbol.

  As shown in FIG. 5, a piezoelectric material 48 and an upper electrode 49 are laminated on the lower electrode 40 in a region facing the partition wall 23 on the opposite side of the diaphragm 21 from the side where the partition wall 23 is provided. A piezoelectric element is formed. An interlayer insulating film 45 and a passivation film 46 are stacked so as to cover the piezoelectric material 48 and the upper electrode 49 stacked on the lower electrode 40. The piezoelectric material 48 and the upper electrode 49 are made of the same material as the piezoelectric material 41 and the upper electrode 42 in the first embodiment.

  As described above, in the second embodiment, the piezoelectric material 48, the upper electrode 49, the interlayer insulating film 45, and the passivation film 46 are formed on the lower electrode 40 in the region facing the partition wall 23 of the diaphragm 21. A laminated film 50 is formed. Further, as shown in FIG. 5, the width of the laminated film 50 is formed wider than the width of the partition wall 23.

<Method for manufacturing droplet discharge head>
Next, a manufacturing method of the droplet discharge head according to the second embodiment will be described with reference to FIG. FIG. 6 shows steps of a method for manufacturing a droplet discharge head according to the second embodiment of the present invention.

  As shown in FIG. 6, in the second embodiment, the constituent materials are stacked through the same steps as in the first embodiment.

  As shown in FIG. 6B, a lower electrode 40, a piezoelectric material 41, and an upper electrode 42, which are piezoelectric elements, are formed on the vibration plate 21 formed on the silicon substrate 110 by film formation. As shown in C), the piezoelectric material 41 and the upper electrode 42 are patterned by a lithoetch method.

  Here, in the second embodiment, unlike the first embodiment, not only the region facing the discharge chamber 22 but also the region facing the partition wall 23 of the diaphragm 21, the piezoelectric material 41 and the upper electrode 42. Is patterned so as to remain.

  As a result, the patterned piezoelectric material 41 and the upper electrode 42 are formed in the region facing the discharge chamber 22 of the vibration plate 21, and the patterned piezoelectric material 41 is formed in the region facing the partition wall 23 of the vibration plate 21. A piezoelectric material 48 made of the above and an upper electrode 49 made of the upper electrode 42 are formed. Next, as in the first embodiment, an insulating film to be the interlayer insulating film 43 is formed.

  Next, as shown in FIG. 6D described above, as in the first embodiment, via holes are formed, and after wiring patterning, for example, a silicon nitride film or the like that becomes the passivation film 44 is formed, and the film formation is performed. The formed insulating film, silicon nitride film and the like are patterned.

  As a result, an interlayer insulating film 43 and a passivation film 44 are formed in a portion of the vibration plate 21 that becomes the actuator 24 in a region facing the discharge chamber 22. In addition, a laminated film 50 in which the piezoelectric material 48 and the upper electrode 49 are covered with the interlayer insulating film 45 and the passivation film 46 is formed in a region facing the partition wall 23 of the vibration plate 21.

  Next, as shown in FIG. 6 (E), as in the first embodiment, recesses to be the discharge chamber 22, the fluid resistance portion 25, and the common liquid chamber 26 are formed on the opposite surface of the silicon substrate 110 by ICP dry etching. To do. Thereby, the liquid chamber substrate 20 in which the actuator 24 and the laminated film 50 are formed is completed.

  Note that, as described above, the piezoelectric material formed on the lower electrode 40 is applied to the piezoelectric material 41 formed in the region facing the discharge chamber 22 of the vibration plate 21 and the region facing the partition wall 23 of the vibration plate 21. The piezoelectric material 48 is formed separately. The width of the piezoelectric material 48 is wider than the width of the partition wall 23.

  Therefore, in the second embodiment, similarly to the first embodiment, the variation in the dimensions of the discharge chamber 22 is very large, and even if the width of the vibration plate 21 is affected, the vibration plate 21 is fixed. A piezoelectric material 48 having high dimensional controllability and high rigidity is formed at the end. As a result, even when the width of the discharge chamber 22 varies, it is possible to make the structure in which the rigidity of the diaphragm 21 hardly changes. In addition to the piezoelectric material 48, the effect can be further enhanced by forming other laminated films.

  As shown in FIG. 6F, similarly to the first embodiment, the nozzle substrate 10 manufactured by high-speed electroforming with a sulfamic acid bath is bonded to the discharge chamber 22 side of the liquid chamber substrate 20.

  Finally, as shown in FIG. 6G, similarly to the first embodiment, a protective substrate 30 in which a concave protective space 31 is separately formed using a silicon substrate 110 by a litho-etching method is formed on the liquid chamber substrate 20. Adhere to the surface on which the piezoelectric element is formed. In addition, an aluminum wiring portion connected to the upper electrode 42, the lower electrode 40, the upper electrode 49, and the like of the piezoelectric element is connected to the drive circuit. Thereby, the droplet discharge head according to the second embodiment is completed.

<Third Embodiment: Droplet Discharge Head>
Next, a droplet discharge head according to a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a view for explaining a droplet discharge head according to a third embodiment of the present invention. In the third embodiment, different driving voltages synchronized with the piezoelectric material 41 and the piezoelectric material 48 of the actuator 24 shown in FIG. 5 are applied to adjust the rigidity of the diaphragm 21.

  As shown in FIG. 7A, a driving pulse is applied to the piezoelectric material 41 in accordance with the timing of ejecting ink droplets during the operation period of ejecting ink droplets. Further, as shown in FIG. 7B, a DC bias synchronized with a drive pulse applied to the piezoelectric material 41 at the start of the operation of ejecting ink droplets is applied to the piezoelectric material 48.

  Thereby, when the piezoelectric material 41 operates, the piezoelectric material 48 can be expanded and contracted by a DC bias, and the tension of the diaphragm 21 can be adjusted. The ejection characteristics for ejecting ink droplets vary depending on slight rigidity variations of the diaphragm 21. Therefore, it is possible to adjust the tension of the diaphragm 21 by the magnitude of the DC bias applied to the piezoelectric material 48 to make the droplet discharge head characteristics uniform. Thus, a driving voltage is applied to the piezoelectric material 48 in accordance with the rigidity to be added.

  Specifically, by adjusting the DC bias applied to the piezoelectric material 48 in the inspection process after the completion of the droplet discharge head, it is possible to reduce the variation in the discharge characteristics of the droplet discharge head. Note that the DC bias applied to the piezoelectric material 48 always has a large cost merit because the control system can be simplified. On the other hand, in order to prevent dielectric breakdown of the piezoelectric material 48 due to DC bias, the piezoelectric material 41 may be applied only when a drive pulse according to image data is supplied.

  As described above, according to the third embodiment, it is possible to increase the rigidity of the fixed end portion of the diaphragm 21 and reduce the variation in the discharge characteristics. Further, by adjusting the rigidity of the fixed end portion of the vibration plate 21, it is possible to reduce the variation in the discharge characteristics.

<Fourth Embodiment: Droplet Discharge Head>
Next, a liquid droplet ejection head according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 8 shows a schematic view of the liquid chamber substrate according to the fourth embodiment of the present invention as viewed from the protective substrate side. FIG. 9 shows a cross-sectional view of FIG. 8 cut along AA ′.

  The fourth embodiment differs from the first embodiment described above in the shape (structure) of the laminated film 47 laminated in the region facing the partition wall 23 of the diaphragm 21.

  That is, as shown in FIG. 9, in the region opposite to the partition wall 23 of the diaphragm 21, as in the first embodiment, the interlayer insulating film 45-1 as the first insulator film and the first insulating film on the lower electrode 40. A laminated film 51 including a passivation film 46-1 as a second insulator film is formed. On the other hand, on the upper electrode 42 forming the piezoelectric element (on the side facing the piezoelectric body 41 of the upper electrode 42, that is, the surface on the protective substrate 30 side in FIG. 9), the interlayer insulating film 43 used in the first embodiment. The passivation film 44 is removed.

  Further, the interlayer insulating film 45-1 extends (extends) so as to cover the predetermined regions of the side surfaces of the piezoelectric material 41 and the upper electrode 42 and the upper surface of the upper electrode 42 (the surface on the side of the protective substrate 30 shown in FIG. 9). Has been. Here, the predetermined region indicates, for example, a peripheral surface (peripheral portion) on the upper surface of the upper electrode 42, and an opening 45-2 of the interlayer insulating film 45-1 is provided on the upper surface of the upper electrode 42. ing. In addition, the passivation film 46-1 has a function of defining the width of the low-rigidity region of the diaphragm 21 as in the first embodiment.

  As in the first embodiment, the passivation film 46-1 is preferably a highly rigid film, and examples thereof include metal nitrides, metal oxides, metal carbides, and the like. As a material, silicon nitride, aluminum nitride, titanium nitride, aluminum oxide, zirconium oxide, yttrium oxide, silicon carbide, titanium carbide, tantalum carbide, or the like can be used.

  The thickness of the passivation film 46-1 is preferably thick in order to define the width of the low-rigidity region of the diaphragm 21, but the passivation film 46-1 is made thick by using the above-described high-rigidity material. In such a case, cracks or the like may occur due to internal stress. Therefore, it is possible to define the low rigidity region of the diaphragm 21 described above, and it is preferable to set the film thickness so that cracks do not occur in the range of about 0.5 to 4 [μm].

  For example, when the passivation film 46-1 using a highly rigid material is laminated so as to cover not only the region facing the partition wall 23 of the diaphragm 21 but also the piezoelectric element, the rigidity of the diaphragm 21 and the passivation film 46. For example, even when a voltage is applied to the piezoelectric element, the displacement of the diaphragm 21 as shown in FIG. 3A may be hindered.

  Therefore, in the fourth embodiment, for example, as shown in FIG. 9 and the like, the displacement of the diaphragm 21 is reduced by removing the passivation film using the high-rigidity material that covers the upper surface of the piezoelectric element in the first embodiment. A high amount of displacement can be obtained without hindering. Thereby, in the fourth embodiment, it is possible to obtain a high-efficiency head having a low discharge voltage and a high discharge capacity.

  Moreover, the interlayer insulating film 45-1 is a film provided between the individual extraction electrode and the piezoelectric element as described later, and does not require high rigidity. Therefore, any insulating material can be used for the interlayer insulating film 45-1. For example, an oxide, a nitride, a carbide, or the like is used, and the silicon oxide film or the silicon nitride film is insulative / film-formed. Generally used for ease.

  In addition, as described above, in the fourth embodiment, the interlayer insulating film 45-1 is configured to remove a part on the upper electrode 42 similarly to the passivation film 46-1, and a predetermined region on the upper surface of the upper electrode 42. It is the structure which coat | covers.

  Thus, in the fourth embodiment, the side surfaces of the piezoelectric body 41 and the interface ends of the piezoelectric body 41, the upper electrode 42, and the lower electrode 40 are protected by the insulating film. Further, in the fourth embodiment, the abnormal discharge between the upper electrode 42 and the lower electrode 40 through the electrode end portion can be prevented, and moisture penetration to the interface can be prevented, and the reliability of the actuator is improved. It becomes possible.

  The film thickness of the interlayer insulating film 45-1 is preferably thin as long as the insulating property can be ensured. However, if it is too thin, the insulating property cannot be ensured, causing a short circuit between the electrodes. For example, the film thickness is preferably in the range of about 200 [nm] to 2 [[mu] m].

  A part of the upper surface of the upper electrode 42 (the opening 45-2 of the interlayer insulating film 45-1 on the surface on the protective substrate 30 side shown in FIG. 9) covers the interlayer insulating film 45-1 and the passivation film 46-1. It will be in a state that is not broken. Therefore, for example, as the material of the upper electrode 42, reliability can be improved by selecting a material having low moisture permeability and high moisture resistance. For example, as the material of the upper electrode 42, it is preferable to use a noble metal material having high chemical stability such as Au, Pt, Pd, Ir, an oxide conductive material, or the like.

  Here, a method of arranging the interlayer insulating film 45-1 and the passivation film 46-1 with respect to the diaphragm 21 will be described with reference to FIG. As shown in FIG. 8, in the region of the diaphragm 21 facing the discharge chamber 22 defined by the partition wall 23, an opening 45-2 of the interlayer insulating film 45-1 and an opening 46 of the passivation film 46-1. -2 are arranged. Here, when the width of the upper surface of the upper electrode 42 is Wu, the width of the opening 45-2 of the interlayer insulating film 45-1 is Wi, and the width of the opening 46-2 of the passivation film 46-1 is Wp, The embodiment is configured to satisfy Wi <Wu <Wp.

  For example, the opening width Wp of the passivation film 46-1 needs to be smaller than the width of the discharge chamber 22, and the opening end thereof does not overlap the opposing region portion of the partition wall 23 due to processing variations of the discharge chamber 22. Must be placed in position. Further, the opening width Wi of the interlayer insulating film 45-1 needs to be narrower than the upper surface width Wu of the upper electrode 42 so that the upper electrode 42 can be protected. As described above, the displacement of the diaphragm 21 is hindered. Therefore, for example, considering the processing variation of the opening width Wi of the interlayer insulating film 45-1 and the upper surface width Wu of the upper electrode 40, Wi-Wu (from the upper surface width Wu of the upper electrode 40 to the interlayer insulating film 45-1). The value obtained by subtracting the opening width Wi) is preferably in the range of about 4 to 20 [μm], for example.

  As a result, in the fourth embodiment, the width of the low-rigidity region in the diaphragm 21 can be defined with high accuracy, and at the same time, a liquid droplet ejection head having high ejection performance and less abnormal discharge / interelectrode leakage is obtained. It becomes possible.

<Method for Manufacturing Droplet Discharge Head According to Fourth Embodiment>
Next, a manufacturing method of the droplet discharge head according to the fourth embodiment will be described with reference to FIG. FIG. 10 shows steps of a method for manufacturing a droplet discharge head according to the fourth embodiment of the present invention. In the fourth embodiment, the constituent materials are stacked through the same manufacturing process as in the first embodiment.

  As shown in FIG. 10A, the lower electrode 40, the piezoelectric material 41, and the upper electrode 42 are laminated on the diaphragm 21 formed by the same process as in FIG. 4B.

  Next, as shown in FIG. 10B, a piezoelectric element is formed by patterning the piezoelectric material 41 and the upper electrode 42 using, for example, general photolithography and etching methods, and the vibration plate 21 is formed. An insulating film to be an interlayer insulating film 45-1 is formed so as to cover the lower electrode 40 and the piezoelectric element.

  Next, as shown in FIG. 10C, when the opening 45-2 is formed in the interlayer insulating film 45-1 covering the upper electrode 40 of the piezoelectric element by using the above-described photolithography or the like, The upper surface of the electrode 42 is exposed.

  Next, as shown in FIG. 10D, an insulating film to be the passivation film 46-1 is stacked on the interlayer insulating film 45-1 by using the same method and patterned, so that the partition walls of the diaphragm 21 are formed. A passivation 46-1 is formed in a region opposite to the region where the partition wall 23 on the side opposite to the side where the 23 is formed is formed. Next, as shown in FIG. 10E, a discharge chamber 22 is formed, and a configuration having the functions of the fourth embodiment can be obtained. As described above, it is possible to improve the discharge performance with the same number of steps as in the first embodiment.

  As described above, according to the fourth embodiment, the width of the low-rigidity area of the diaphragm 21 is defined by the thin film material pattern with high processing accuracy formed in the area facing the partition wall 23 of the diaphragm 21, and the ejection characteristics Can be stabilized. Further, since the laminated film on the piezoelectric element is removed, the vibration characteristics of the diaphragm 21 can be improved. In addition, it is possible to obtain a liquid droplet ejection head with low cost and stable quality without increasing the number of steps.

<Fifth Embodiment: Droplet Discharge Head>
Next, a droplet discharge head according to a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 11 shows a cross-sectional view of FIG. 8 cut along BB ′. FIG. 12 shows a cross-sectional view of FIG. 8 taken along the line CC ′.

  In the fifth embodiment, an individual extraction electrode that supplies a voltage to the upper electrode of the piezoelectric element in the configuration of the fourth embodiment is disposed. Further, the individual extraction electrode is provided on an interlayer insulating film 45-1 covering a predetermined region on the upper electrode of the piezoelectric element, and the upper electrode 42 and the individual extraction electrode are provided by a contact hole provided in the interlayer insulator 45-1. And are connected.

  The fifth embodiment will be described with reference to FIG. 8 described above. The individual extraction electrode 52 is disposed on the liquid chamber substrate 20. Further, a contact hole 45-3 is formed in the interlayer insulating film 45-1 laminated on the upper electrode 42 in the vicinity of the longitudinal end of the discharge chamber 22. The individual extraction electrode 52 is connected to and electrically connected to the upper electrode 42 through a contact hole 45-3 formed in the interlayer insulating film 45-1.

  The contact hole 45-3 provided in the interlayer insulating film 45-1 is formed separately from the opening 45-2 of the interlayer insulating film 45-1. The size of the contact hole 45-3 is preferably reduced within a range in which the contact resistance between the individual extraction electrode 52 and the upper electrode 42 can be sufficiently reduced.

  As the material of the individual extraction electrode 52, for example, any metal, alloy, conductive compound, or the like can be used. The individual extraction electrode 52 is preferable because, for example, a metal / alloy having a small electric resistance is used so that the thickness of the individual extraction electrode 52 is reduced and the displacement of the diaphragm 21 is not hindered. In addition, as such a metal / alloy material, a general material can be used, for example, Ag, Al, Au, Cu, etc., an alloy material containing these, etc. can be illustrated. Moreover, as a general wiring material, Al, Al—Si alloy, etc. are preferable because they are inexpensive.

  FIG. 11 shows a cross-sectional view in the short direction of the contact hole 45-3 portion, and FIG. 12 shows a cross-sectional view in the longitudinal direction of the contact hole 45-3 portion. As shown in FIGS. 11 and 12, the passivation film 46-1 is formed so as to cover the individual extraction electrode 52 formed on the contact hole 45-3.

  As described in the fourth embodiment, the passivation layer 46-1 in the fifth embodiment has a function of defining the width of the low-rigidity region of the diaphragm 21, and protects the electrode material above the contact hole 45-3. It has the function to do.

  As described above, the individual lead-out wiring 52 formed on the upper side of the contact hole 45-3 (the protection substrate 30 side shown in FIGS. 11 and 12) is protected by the passivation film 46-1. Further, the passivation film 46-1 protects the peripheral portion of the contact hole 45-3 so as to include the end portion of the individual extraction electrode 52.

  This makes it possible to ensure connection reliability at the interface between the interlayer insulating film 45-1 and the individual extraction electrode 52 and at the interface between the upper electrode 42 and the individual extraction electrode 52.

<Method for Manufacturing Droplet Discharge Head According to Fifth Embodiment>
Next, a manufacturing method of the droplet discharge head according to the fifth embodiment will be described with reference to FIG. FIG. 13 shows steps of a method for manufacturing a droplet discharge head according to the fifth embodiment of the present invention. Note that the fifth embodiment can be formed with the same number of steps as the fourth embodiment.

  13A and 13B are the same steps as those of the fourth embodiment shown in FIGS. 10A and 10B.

  Next, as shown in FIG. 13C, when the opening 45-2 of the interlayer insulating film 45-1 shown in FIG. 10C is formed, the interlayer insulating film 45-1 on the upper electrode 40 is formed. Then, a contact hole 45-3 is formed. Further, the individual extraction electrode 52 is formed on the interlayer insulating film 45-1 in which the contact hole 45-3 is formed by using, for example, a sputtering method.

  Next, as shown in FIG. 13D, an insulating film to be the passivation film 46-1 is laminated so as to cover the individual extraction electrode 52 and the interlayer insulating film 45-1 formed in the contact hole 45-3. . Next, as shown in FIG. 13E, a discharge chamber 22 can be formed to obtain a configuration having the function of the fifth embodiment.

  As described above, in the fifth embodiment, a low rigidity region of the diaphragm 21 can be defined using a laminated film with high processing accuracy, so that stable discharge performance can be obtained regardless of processing variations in the discharge chamber. It becomes possible. Further, by protecting the individual extraction electrode 52 with a configuration that does not hinder the displacement of the vibration plate 21, it is possible to obtain a highly reliable droplet discharge head. In addition, the laminated film that defines the low-rigidity region of the vibration plate 21 serves as a protective layer that protects the upper electrode end and a protective layer that protects the individual extraction electrode 52, without increasing the number of steps. It is possible to obtain a stable discharge quality and a highly reliable droplet discharge head.

<Sixth Embodiment: Ink Cartridge>
Next, an ink cartridge according to a sixth embodiment to which the above-described droplet discharge head of the present invention can be applied will be described with reference to FIG. FIG. 14 shows a perspective view of a head-integrated ink cartridge according to the sixth embodiment of the present invention. In the sixth embodiment, an ink tank that supplies ink to any one of the droplet discharge heads of the above-described embodiments is integrated.

  Specifically, as illustrated in FIG. 14, the ink cartridge 60 includes the inkjet head 61 according to each of the above-described embodiments having the nozzle substrate 10 and the like, and an ink tank 62 that supplies ink to the inkjet head 61. It is an integrated one.

  As described above, by using the droplet discharge head according to each of the embodiments described above for the ink cartridge 60, it becomes possible to improve the reliability and the cost of the head, thereby improving the yield and reliability of the ink cartridge. In addition, the cost of the head-integrated ink cartridge can be reduced.

<Seventh embodiment: inkjet recording apparatus>
Next, an example of an inkjet recording apparatus according to a seventh embodiment to which the above-described droplet discharge head of the present invention can be applied will be described with reference to FIGS. FIG. 15 is a perspective view of an ink jet recording apparatus according to the seventh embodiment of the present invention. FIG. 16 is a side view of the ink jet recording apparatus according to the seventh embodiment of the present invention.

  In the seventh embodiment, an inkjet head that is a droplet discharge head according to the present invention is mounted on an inkjet recording apparatus that is an image forming apparatus.

  As shown in FIG. 15, the ink jet recording apparatus 70 includes a carriage that can move in the main scanning direction inside the recording apparatus main body 71, a recording head that includes the ink jet head according to the present invention mounted on the carriage, and supplies ink to the recording head. A printing mechanism 72 composed of an ink cartridge or the like is housed. Further, a paper feed cassette (or a paper feed tray) 74 capable of stacking a large number of sheets 73 from the front side can be detachably attached to the lower part of the apparatus main body 71.

  Further, the ink jet recording apparatus 70 opens the manual feed tray 75 for manually feeding the paper 73 and takes in the paper 73 fed from the paper feed cassette 74 or the manual feed tray 75, and the printing mechanism unit 72 performs the required operation. After the image is recorded, it is discharged to a discharge tray 76 mounted on the rear side.

  The printing mechanism 72 holds the carriage 83 slidably in the main scanning direction by a main guide rod 81 and a sub guide rod 82 which are guide members horizontally mounted on left and right side plates (not shown). Further, the carriage 83 is a recording composed of an ink jet head which is a droplet discharge head according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The head 84 is mounted with a plurality of ink discharge ports (nozzles) arranged in a direction crossing the main scanning direction, and the ink droplet discharge direction is directed downward.

  In addition, each ink cartridge 85 for supplying ink of each color to the recording head 84 is replaceably mounted on the carriage 83.

  The ink cartridge 85 has an atmosphere port communicating with the atmosphere above, a supply port for supplying ink to the inkjet head below, and a porous body filled with ink inside, and a capillary tube for the porous body. The ink supplied to the inkjet head is maintained at a slight negative pressure by force. Further, although the recording heads 84 of the respective colors are used here as the recording heads, one head having nozzles for ejecting ink droplets of the respective colors may be used.

  Here, the carriage 83 is slidably fitted to the main guide rod 81 on the rear side (downstream side in the paper conveyance direction), and slidably mounted on the secondary guide rod 82 on the front side (upstream side in the paper conveyance direction). It is location. In order to move and scan the carriage 83 in the main scanning direction, a timing belt 90 is stretched between a driving pulley 88 and a driven pulley 89 that are rotationally driven by a main scanning motor 87, and the timing belt 90 is fixed to the carriage 83. The carriage 83 is reciprocated by forward and reverse rotation of the main scanning motor 87.

  On the other hand, in order to convey the paper 73 set in the paper feed cassette 74 to the lower side of the recording head 84, the paper feed roller 91 and the friction pad 92 for separating and feeding the paper 73 from the paper feed cassette 74 and the paper 73 are guided. Guide member 93, a conveyance roller 94 that reverses and conveys the fed paper 73, a conveyance roller 95 that is pressed against the peripheral surface of the conveyance roller 94, and a tip that defines a feeding angle of the paper 73 from the conveyance roller 94 A roller 96 is provided. The transport roller 94 is rotationally driven by a sub-scanning motor 97 through a gear train.

  Corresponding to the range of movement of the carriage 83 in the main scanning direction, there is provided a printing receiving member 99 which is a sheet guide member for guiding the sheet 73 fed from the conveying roller 94 below the recording head 84.

  A conveyance roller 101 and a spur 102 which are rotationally driven to send out the paper 73 in the paper discharge direction are provided on the downstream side of the printing receiving member 99 in the paper conveyance direction, and a paper discharge roller for sending the paper 73 to the paper discharge tray 76. 103, a spur 104, and guide members 105 and 106 that form a paper discharge path are disposed.

  At the time of recording, the recording head 84 is driven according to the image signal while moving the carriage 83 to eject ink onto the stopped sheet 73 to record one line, and after conveying the sheet 73 by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 73 has reached the recording area, the recording operation is terminated and the sheet 73 is discharged.

  Further, a recovery device 107 for recovering defective ejection of the recording head 84 is disposed at a position outside the recording area on the right end side in the moving direction of the carriage 83. The recovery device 107 includes a cap unit, a suction unit, and a cleaning unit.

  The carriage 83 moves to the recovery device 107 side during printing standby, capping the recording head 84 by the capping unit, and keeps the ejection port portion in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.

  When a discharge failure occurs, the discharge port (nozzle) of the recording head 84 is sealed by the capping unit, and bubbles and the like are sucked out from the discharge port by the suction unit through the tube. Etc. are removed by the cleaning means to recover the ejection failure. The sucked ink is discharged to a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.

  As described above, by applying the droplet discharge head according to any of the above-described embodiments to the recording head 84 of the inkjet recording apparatus 70, it is possible to prevent ink droplet discharge failure due to vibration plate drive failure and to stabilize Ink droplet ejection characteristics can be obtained, and the image quality can be improved. In addition, the numerical values and materials such as the film thickness described in the above-described embodiments are not limited to this.

  As described above, a laminated film is formed of an actuator constituent material different from the diaphragm material in a region facing the diaphragm of the diaphragm, and the width of the laminated film is wider than the width of the diaphragm. It is possible to increase the rigidity of the fixed end portion and reduce the variation in discharge characteristics due to the variation in rigidity of the diaphragm. In addition, the width of the low-rigidity part of the diaphragm is determined (specified) by a thin film material pattern with little variation in the processing width, so that the influence of the variation in the processing width of the discharge chamber is reduced and the discharge characteristics are stabilized. It becomes possible.

  In addition, the number of steps is not increased compared to conventional methods, and the variation in the rigidity of the diaphragm is reduced, forming a diaphragm of stable quality at a low cost, achieving both low cost and reliability. An ejection head can be manufactured.

  In addition, by providing a piezoelectric material in the region facing the diaphragm of the diaphragm and making the width of the piezoelectric material wider than the width of the diaphragm, the rigidity of the fixed end of the diaphragm is increased, and ejection due to variations in the rigidity of the diaphragm It becomes possible to reduce variation in characteristics. In addition, since the width of the low-rigidity portion of the diaphragm is determined (defined) by the piezoelectric material with less variation in the processing width, the influence of variations in the processing width of the discharge chamber is reduced, and the discharge characteristics can be stabilized. It becomes possible.

  Further, different drive pulse voltages are applied to the first piezoelectric material provided in the region facing the partition wall of the diaphragm and the second piezoelectric material provided in the region facing the discharge chamber of the diaphragm, for example, When a pulse voltage according to image data is applied to the first piezoelectric material, a voltage is applied to the second piezoelectric material to cause contraction. As a result, it is possible to control the ejection performance by changing the tension of the diaphragm.

  In addition, by applying a DC bias to the second piezoelectric material to cause contraction and controlling the tension of the diaphragm in the discharge chamber to be constant without providing a complicated control system, the rigidity of the diaphragm when the diaphragm operates It is possible to reduce the variation in the discharge characteristics due to the variation in the above. This makes it possible to manufacture a droplet discharge head that achieves both low cost and reliability.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

DESCRIPTION OF SYMBOLS 1 Droplet discharge head 10 Nozzle board | substrate 11 Nozzle hole 12 Ink droplet 13 Recording paper 20 Liquid chamber board | substrate 21 Diaphragm 21-1, 21-3 Silicon oxide film 21-2 Polysilicon 22 Discharge chamber 23 Partition 24 Actuator 25 Flow resistance Unit 26 Common liquid chamber 30 Protective substrate 31 Protective space 32 Column 33 Ink supply hole 40 Lower electrodes 41, 48 Piezoelectric materials 42, 49 Upper electrodes 43, 45, 45-1 Interlayer insulating films 44, 46, 46-1 Passivation film 45 -2 Interlayer insulating film opening 45-3 Contact hole 46-2 Passivation film opening 47, 50, 51 Laminated film 52 Individual extraction electrode 60 Ink cartridge 61 Inkjet head 62 Ink tank 70 Inkjet recording apparatus 71 Recording apparatus main body 72 Printing mechanism Section 73 Paper 74 Paper feed cassette 75 Manual feed tray 76 Tray 81 Main guide rod 82 Subordinate guide rod 83 Carriage 84 Recording head 85 Ink cartridge 87 Main scanning motor 88 Drive pulley 89 Driven pulley 90 Timing belt 91 Feed roller 92 Friction pad 93 Guide member 94 Transport roller 95 Transport roller 96 Tip roller 97 Sub-scanning motor 99 Printing receiving member 101 Conveying rollers 102, 104 Spur 103 Paper discharge rollers 105, 106 Guide member 107 Recovery device

JP 2007-210198 A Japanese Patent No. 3954813 Japanese Patent No. 4068784 Japanese Patent No. 4117504

Claims (11)

A nozzle plate having a plurality of nozzle holes for discharging droplets, a vibration plate capable of vibration, and a discharge chamber formed corresponding to each of the nozzle holes are partitioned between the nozzle plate and the vibration plate. A liquid droplet ejection head comprising: a partition; and a pressure generating means for generating a pressure to pressurize the liquid in the ejection chamber for each ejection chamber by displacing and deforming the diaphragm.
In a region facing the partition on the opposite side of the diaphragm on which the partition is provided, a laminated film that increases the rigidity of the diaphragm along the partition is provided.
The droplet discharge head according to claim 1, wherein the width of the laminated film is wider than the width of the partition wall.   The droplet discharge head according to claim 1, wherein the stacked film includes one or both of a silicon oxide film and a silicon nitride film.   The droplet discharge head according to claim 1, wherein the laminated film includes a piezoelectric element.   4. The droplet discharge head according to claim 1, wherein the rigidity of the diaphragm is adjusted by applying a drive voltage to the piezoelectric element. 5.   The liquid droplet ejection head according to claim 4, wherein different driving voltages synchronized with the pressure generating unit and the piezoelectric element are applied.   6. The liquid droplet ejection head according to claim 4, wherein the driving voltage is applied to the piezoelectric element in accordance with rigidity to be added. The pressure generating means has a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode along a region facing the discharge chamber on the side opposite to the side where the discharge chamber is provided on the diaphragm.
The laminated film includes two layers of a first insulator film formed on the diaphragm and a second insulator film formed on the first insulator film,
2. The droplet discharge head according to claim 1, wherein the first insulator film extends so as to cover a predetermined region on the upper electrode of the piezoelectric element. An individual extraction electrode for supplying a voltage to the upper electrode of the piezoelectric element;
The individual extraction electrode is provided on the first insulator film covering a predetermined region on the upper electrode, and the upper electrode and the individual extraction electrode are formed by a contact hole provided in the first insulator film. The droplet discharge head according to claim 7, wherein the droplet discharge head is connected. A droplet discharge head according to any one of claims 1 to 8,
An ink cartridge comprising an ink tank for supplying ink to the droplet discharge head.   An image forming apparatus comprising the droplet discharge head according to claim 1. A nozzle plate having a plurality of nozzle holes for discharging droplets, a vibration plate capable of vibration, and a discharge chamber formed corresponding to each of the nozzle holes are partitioned between the nozzle plate and the vibration plate. Droplet discharge head manufacturing method for manufacturing a droplet discharge head comprising: a partition wall; and pressure generating means for generating pressure to pressurize the liquid in the discharge chamber for each discharge chamber by displacing and deforming the diaphragm Because
A laminated film that forms a laminated film that increases the rigidity of the diaphragm along the partition in a region facing the partition opposite to the side on which the partition is provided of the diaphragm wider than the width of the partition. A method for manufacturing a droplet discharge head, comprising a forming step.

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