Actuator, liquid discharge head, liquid discharge device, and method for manufacturing an actuator

Abstract

The present invention provides an actuator capable of suppressing a decrease in the vibration displacement of a piezoelectric element, a liquid discharge head, a liquid discharge device, and a method for manufacturing the actuator. [Solution] The actuator 110 is laminated on a flow channel substrate 100, which is a substrate on which a pressurized liquid chamber 4 is formed, and comprises a vibrating membrane 103 that forms part of the wall surface of the pressurized liquid chamber 4, and a piezoelectric element 5 arranged on the side of the vibrating membrane 103 opposite to the side that forms the wall surface of the pressurized liquid 4. The insulating film 8 that electrically insulates at least the second lead wiring, which is a wiring portion drawn out from the second electrode 53, from the piezoelectric membrane 52 and the first electrode 51 has an insulating film opening 8a, and the central part of the second electrode 51 is an area that is not covered by the insulating film 8.

Description

Technical Field

[0001] The present invention relates to an actuator, a liquid ejection head, a device for ejecting a liquid, and a method for manufacturing an actuator.

Background Art

[0002] Conventionally, a piezoelectric element composed of a diaphragm that forms part of the wall surface of a liquid chamber and is laminated on a substrate in which the liquid chamber is formed, a first electrode laminated on the surface of the diaphragm opposite to the side forming the wall surface of the liquid chamber, a piezoelectric portion laminated on the first electrode, and a second electrode laminated on the piezoelectric portion, a wiring portion drawn out from at least the second electrode, an insulating film that electrically insulates between the piezoelectric portion and the first electrode, and a protective film that protects the piezoelectric element from moisture is known.

[0003] Patent Document 1 describes an actuator in which the entire piezoelectric element is covered with the insulating film (first insulating film), and the wiring portion formed on the insulating film and the piezoelectric element are covered with the insulating protective film (second insulating film).

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1, since the entire piezoelectric element is covered with the insulating film and the protective film, there is a problem that the vibration displacement of the piezoelectric element is low.

Means for Solving the Problems

[0005] To solve the above-mentioned problems, the present invention provides an actuator comprising: a vibrating membrane laminated on a substrate having a liquid chamber formed thereon and constituting a part of the wall surface of the liquid chamber; a piezoelectric element composed of a first electrode laminated on the side of the vibrating membrane opposite to the side constituting the wall surface of the liquid chamber, a piezoelectric portion laminated on the first electrode, and a second electrode laminated on the piezoelectric portion; a wiring portion covering the piezoelectric element and extending at least from the second electrode; an insulating film electrically insulating the piezoelectric portion and the first electrode; and a protective film protecting the piezoelectric element from moisture, wherein the piezoelectric element has a region not covered by the insulating film, and the protective film covers the entire piezoelectric element. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress the decrease in vibration displacement of the piezoelectric element. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic cross-sectional view showing a liquid discharge head using a nozzle vibration method in Embodiment 1. [Figure 2] A schematic perspective view showing the liquid dispensing head. [Figure 3] Enlarged cross-sectional view of section X in Figure 1. [Figure 4] A diagram illustrating the insulating film and the region where the protective film is formed. [Figure 5] A schematic diagram showing a configuration in which the insulating film covers the entire piezoelectric element, and the protective film covers a portion of the piezoelectric element. [Figure 6] A diagram illustrating the process of forming a vibrating film on a channel substrate. [Figure 7] A diagram illustrating the process of forming a piezoelectric element on a diaphragm. [Figure 8] A diagram illustrating the process of forming an insulating film. [Figure 9] A diagram illustrating the process of forming the lead wires. [Figure 10] A diagram illustrating the process of forming an insulating film aperture. [Figure 11]A diagram illustrating the process of forming a protective film. [Figure 12] A diagram illustrating the etching process of the protective film. [Figure 13] A diagram illustrating the process of forming a film on the nozzle formation area. [Figure 14] A diagram illustrating the process of forming a nozzle. [Figure 15] A diagram illustrating the process of forming a pad opening. [Figure 16] A diagram illustrating the process of forming a pressurized liquid chamber. [Figure 17] A schematic diagram of a liquid discharge head according to Embodiment 2, in which the actuator of the present invention is applied to a unimorph type piezo head. [Figure 18] A schematic diagram illustrating a printing apparatus, which is an inkjet recording apparatus used as a liquid ejection device in this embodiment. [Figure 19] A plan view illustrating an example of a head unit of the printing apparatus according to this embodiment. [Figure 20] Plan view illustrating the main components of the printing apparatus in this example. [Figure 21] Side view of the main components of the printing apparatus in this example. [Figure 22] Plan view illustrating the main components of another example of a liquid dispensing unit. [Figure 23] A front view diagram of yet another example of a liquid dispensing unit. [Modes for carrying out the invention]

[0008] The best mode for carrying out the present invention will be described below with reference to the drawings. It should be noted that a person skilled in the art will find it easy to modify the present invention within the scope of the claims to create other embodiments, and such modifications are included within the scope of these claims. The following description is an example of the best mode in this invention and does not limit the scope of these claims.

[0009] The liquid ejection head in Embodiment 1 is a nozzle plate vibration type liquid ejection head that ejects the liquid in the pressurized liquid chamber from the nozzle by varying the pressure of the pressurized liquid chamber, which is a liquid chamber, by an actuator unit having a nozzle. The nozzle plate vibration method has a feature that droplets can be ejected with a smaller force compared to a general unimorph type piezo head (which ejects liquid by vibrating the surface facing the surface having the nozzle of the pressurized liquid chamber), and power saving of the actuator can be achieved.

[0010] When the nozzle density is increased, the space for laying out the wiring for voltage application is limited, and it becomes difficult to construct the wiring on the substrate surface. By constructing the wiring and drive circuit in the substrate, even in a configuration with a high nozzle density, the wiring can be laid out. Generally, lead zirconate titanate (PZT) is widely used as the material of the piezoelectric element because of its high piezoelectric characteristics, but the film formation and crystallization temperature of PZT requires 600 °C or higher. When PZT is used as the material of the piezoelectric element, the drive circuit and its wiring in the substrate cannot withstand high temperatures, so a piezoelectric material with a lower film formation temperature than PZT is required as the piezoelectric material. In that case, it is inevitable to select a material with lower piezoelectric characteristics than PZT. However, as described above, the nozzle plate vibration method has a feature that droplets can be ejected with a smaller force compared to a general unimorph type piezo head (which ejects liquid by vibrating the surface facing the surface having the communication port communicating with the nozzle of the pressurized liquid chamber), so even if a material with lower piezoelectric characteristics than PZT is selected, the droplets can be ejected well. Therefore, even a piezoelectric material such as a non-lead material with a low film formation and crystallization temperature but small power can eject the droplets well. As a result, the wiring and drive circuit can be constructed in the substrate, enabling high density. Furthermore, since the nozzle plate vibration method can reduce the volume of the pressurized liquid chamber, the head can also be miniaturized.

[0011] FIG. 1 is a cross-sectional view schematically showing the nozzle plate vibration type liquid ejection head 1 in Embodiment 1, and FIG. 2 is a perspective view schematically showing the liquid ejection head 1. The liquid ejection head 1 includes an actuator 110, a flow path substrate 100 serving as a substrate, and a frame member 120.

[0012] The actuator 110 is in a thin film shape and has a diaphragm 103, a plurality of nozzles 2 for ejecting liquid, and an annular piezoelectric element 5 disposed around the nozzles 2. The flow path substrate 100 serving as a substrate has a plurality of pressurized liquid chambers (also referred to as individual liquid chambers) 4 that communicate with the plurality of nozzles 2 respectively. The frame member 120 has a common liquid chamber 3 that leads to the plurality of pressurized liquid chambers 4.

[0013] At both ends of the liquid ejection head 1, electrical connection pads 6 for electrically connecting to electrical components such as an external power source are provided.

[0014] FIG. 3 is an enlarged cross-sectional view of the X portion in FIG. 1. The diaphragm 103 is formed on the flow path substrate 100. As the material of the diaphragm 103, metal oxides such as SiO2, SiN, and ZrO, semiconductors such as SiC and GaAs, resins, etc. can be used. In order to increase the displacement of the diaphragm 103, a material with a low Young's modulus is desirable. Considering the difference in the linear expansion coefficient from the flow path substrate 100, SiO2 with a relatively small difference is desirable as the material of the diaphragm 103. Also, from the perspective of cost, SiO2 is desirable as the material of the diaphragm 103.

[0015] The actuator 110 has a nozzle forming portion (film) 111 in which a plurality of nozzles 2 are formed and which covers the piezoelectric element 5. A water repellent film may be provided on the nozzle surface of this nozzle forming portion 111. By forming a liquid repellent film on the nozzle surface, adhesion of liquid to the nozzle surface can be suppressed, and the liquid ejected from the nozzles 2 can be prevented from being affected by the liquid adhering to the nozzle surface. When the solvent of the liquid is aqueous, perfluorodecyltrichlorosilane or perfluorooctyltrichlorosilane can be used as the material of the liquid repellent film. A pad opening 10 is formed at the end of the nozzle forming portion 111, and the electrical connection pad 6 is connected to an external electrical component through the pad opening 10.

[0016] The piezoelectric element 5 of the actuator 110 has a first electrode 51 (also called the lower electrode), a piezoelectric film 52 which is the piezoelectric part, and a second electrode 53 (also called the upper electrode). The portion of the first electrode 51 where the piezoelectric film 52 is not laminated, the portion of the piezoelectric film 52 where the second electrode 53 is not laminated, and the end of the second electrode 53 are covered with an insulating film 8.

[0017] The insulating film 8 electrically insulates at least the second lead wire 9b, which is drawn out from the second electrode 53, from the piezoelectric film 52 and the first electrode 51. The insulating film 8 can be made from an oxide of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), or tungsten (W). Alternatively, a nitride of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), or tungsten (W) can be used. The insulating film 8 may also contain multiple of the above oxides or nitrides.

[0018] As for the insulating film 8, similar to the vibrating film 103, it is desirable to have a low Young's modulus and a coefficient of thermal expansion close to that of the constituent material, so SiO2 is particularly preferred. Furthermore, reliability can be improved by using a dense metal oxide or the above-mentioned nitride as the insulating film 8, but since the above-mentioned metal oxide and nitride are hard, it is preferable to make the insulating film 8 extremely thin when using a metal oxide or nitride.

[0019] In the area of ​​the insulating film 8 corresponding to the center of the second electrode 53 of the piezoelectric element 5, the insulating film 8 has been removed, resulting in an insulating film opening 8a, and the central part of the second electrode 53 of the piezoelectric element 5 is an area not covered by the insulating film 8.

[0020] The insulating film 8 has a perforated first contact 7a for electrically connecting to the first electrode 51 and a perforated second contact 7b for electrically connecting to the second electrode 53. On this insulating film 8, a first lead wire 9a is formed as a wiring portion drawn out from the first electrode 51 of the piezoelectric element 5, and a second lead wire 9b is formed as a wiring portion drawn out from the second electrode 53 of the piezoelectric element 5.

[0021] The first lead wire 9a, drawn from the first electrode 51, is extended to one end of the liquid discharge head 1, and the second lead wire 9b is extended to the other end of the liquid discharge head. The ends of the first lead wire 9a and the second lead wire 9b are exposed to the outside to form an electrical connection pad 6.

[0022] Alternatively, electrical connection pads 6 may be formed on both ends of the protective film 11 covering the first and second lead wires 9a and 9b, and the lead wires 9a and 9b may be electrically connected to the electrical connection pads 6 on the protective film 11 via perforated contacts provided on both ends of the protective film 11.

[0023] The first lead wire 9a, the second lead wire 9b, and the piezoelectric element 5 are covered with a moisture-resistant protective film 11. This prevents moisture that has entered the nozzle forming section 111, which is made of resin, from entering the first lead wire 9a, the second lead wire 9b, and the piezoelectric element 5, thereby suppressing corrosion of each lead wire and preventing short circuits.

[0024] Furthermore, it is preferable that the protective film 11 has electrical insulating properties. By having both electrical insulating and moisture-proof functions as the protective film 11, the actuator 110 can be made thinner compared to when an insulating film is formed beneath the protective film 11. This makes the vibrating membrane 103 more easily deformable, and the vibration efficiency can be improved.

[0025] As the protective film 11, it is preferable to use SiN (silicon nitride), which is widely used as a moisture-proof film for semiconductors, so that the protective film 11 can have two functions: electrical insulation and moisture resistance. In addition, as the material of the protective film 11, oxides of Al (aluminum), Ta (tantalum), Nb (niobium), Ti (titanium), Hf (hafnium), Zr (zirconium), and W (tungsten) that are easy to form dense films by atomic layer deposition (ALD) can also be used. Furthermore, the protective film 11 may also be a metal nitride of Al (aluminum), Ta (tantalum), Nb (niobium), Ti (titanium), Hf (hafnium), Zr (zirconium), and W (tungsten). Moreover, it may contain multiple types of the above metal oxides and nitrides.

[0026] Figure 4 illustrates the formation regions of the insulating film 8 and the protective film 11. The shaded area in Figure 4 indicates the formation region of the insulating film 8, and the gray area in Figure 4 indicates the formation region of the protective film 11. As shown in Figure 4, the portion of the insulating film 8 corresponding to the center of the second electrode 53 of the piezoelectric element 5 has the insulating film 8 removed, forming an insulating film opening 8a, and the central part of the second electrode 53 of the piezoelectric element 5 is an area not covered by the insulating film 8. Therefore, in Embodiment 1, the portion of the first electrode 51 where the piezoelectric film 52 is not laminated, the portion of the piezoelectric film 52 where the second electrode 53 is not laminated, and the ends of the second electrode 53 are covered by the insulating film 8, while the central part of the second electrode 53 is an area not covered by the insulating film 8. The protective film 11 covers the entire piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b.

[0027] Thus, in Embodiment 1, a portion of the piezoelectric element 5 is not covered by the insulating film 8. This allows for increased vibration displacement of the piezoelectric element 5 compared to a configuration where the entire piezoelectric element 5 is covered by the insulating film 8 and the protective film 11. Therefore, even when using a piezoelectric material with a low film formation and crystallization temperature but low power, such as a lead-free material, the piezoelectric element 5 can vibrate and displace well, allowing the vibrating film 103 to vibrate well and improving the droplet ejection efficiency.

[0028] Since the piezoelectric film 52 of the piezoelectric element 5 is displaced in the stacking direction of the first electrode 51, the piezoelectric film 52, and the second electrode 53, the piezoelectric element 5 can be effectively vibrated and displaced by providing a region of the second electrode 53 that is not covered by the insulating film 8.

[0029] Furthermore, as shown in Figure 5, by covering the entire piezoelectric element 5 with the insulating film 8 and having the protective film 11 cover only the lead wires 9a and 9b, the number of films covering the piezoelectric element 5 can be reduced from two layers to one, thereby increasing the vibration displacement of the piezoelectric element 5. However, in the configuration shown in Figure 5, there is a risk that moisture entering the nozzle forming section 111 may enter through the interface X1 between the insulating film 8 and the protective film 11 around the first contact 7a connecting the first electrode 51 and the first lead wire 9a, and through the interface X2 between the insulating film 8 and the protective film 11 around the second contact 7b connecting the second electrode 53 and the second lead wire 9b. As a result, there is a risk that the moisture entering through these interfaces X1 and X2 may cause corrosion of the lead wires 9a and 9b, and the electrodes 51 and 53 of the piezoelectric element 5, or cause a short circuit.

[0030] In contrast, in Embodiment 1, the insulating film 8 covers only a portion of the piezoelectric element 5, while the protective film 11 covers the entire piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b. This prevents the formation of an interface between the other film and the protective film 11 near the piezoelectric element 5 and near each lead wire 9a, 9b, and effectively suppresses corrosion of each lead wire 9a, 9b and each electrode 51, 53 of the piezoelectric element 5 due to moisture. Therefore, it is possible to suppress the decrease in vibration displacement of the piezoelectric element 5 and drive the piezoelectric element 5 stably over time, thereby obtaining a highly reliable actuator 110.

[0031] Furthermore, the portions of the first electrode 51 where the piezoelectric film 52 is not laminated and the portions of the piezoelectric film 52 where the second electrode 53 is not laminated are covered with the insulating film 8, thereby providing good electrical insulation between the second lead wire 9b formed on the insulating film 8 and the piezoelectric film 52 and the first electrode 51. This allows the piezoelectric element 5 to be driven stably. In addition, the insulating film 8 is not completely removed from the second electrode 53, but covers the nozzle-side end and a portion of the opposite end of the second electrode 53. With this configuration, the portions of the piezoelectric film 52 where the second electrode 53 is not laminated and the portions of the first electrode 51 where the piezoelectric film 52 is not laminated can be reliably covered with the insulating film 8.

[0032] The insulating film 8 requires a film thickness of several hundred nanometers to several micrometers. While a thicker film improves electrical insulation and reliability, it also reduces the vibration displacement of the piezoelectric element, lowering droplet ejection efficiency. However, as in Embodiment 1, by providing an insulating film opening 8a, the vibration displacement of the piezoelectric element 5 can be increased compared to the case where the entire piezoelectric element 5 is covered with the insulating film 8. Therefore, by providing the insulating film opening 8a, the increased vibration displacement allows for a thicker insulating film 8 in the areas where the piezoelectric film 52 is not laminated on the first electrode 51 and the areas where the second electrode 53 of the piezoelectric film 52 is not laminated. Thus, it is possible to improve electrical insulation while maintaining the same droplet ejection efficiency as in the conventional method.

[0033] In the example shown in Figure 4, the insulating film 8 covers the portion of the first electrode 51 of the piezoelectric element 5 where the piezoelectric film 52 is not laminated, the portion of the piezoelectric film 52 where the second electrode 53 is not laminated, and the end of the second electrode 53. However, for example, the insulating film 8 may be used to cover only the area where the first lead wire 9a and the second lead wire 9b of the piezoelectric element 5 are arranged. By using such a configuration, the rigidity of the piezoelectric element 5 can be further reduced while ensuring electrical insulation between each lead wire 9a, 9b and the piezoelectric element 5, thereby improving vibration efficiency.

[0034] Furthermore, for example, if the first lead wire 9a is led out from the end of the first electrode 51 and connected to the first electrode 51 without going through the first contact 7a, the insulating film 8 only needs to electrically insulate the second lead wire 9b from the piezoelectric film 52 and the first electrode 51.

[0035] In Embodiment 1, as shown in Figure 4, the insulating film 8 is formed only around the piezoelectric element 5. Therefore, in the vibration region 103a where the vibrating membrane 103 vibrates due to the displacement vibration of the piezoelectric element 5, the areas other than the piezoelectric element 5 arrangement area and the arrangement area of ​​each lead wire are covered by the insulating film 8, forming an uncovered portion 8b. Similarly, the protective film 11 is formed only around the piezoelectric element 5 and each lead wire 9a, 9b, and the areas of the vibration region 103a other than the piezoelectric element 5 arrangement area and the arrangement area of ​​each lead wire are covered by the protective film 11, forming an uncovered portion 11a. By having the uncovered portion 8b of the insulating film and the uncovered portion 11a of the protective film in the vibration region of the vibrating membrane in this way, the rigidity of the vibration region 103a can be reduced. As a result, the vibration region 103a can be easily vibrated by the displacement of the piezoelectric element 5, and the vibration efficiency can be increased compared to a configuration in which the entire vibration region 103a is covered by the protective film 11 and insulating film 8, thereby increasing the droplet ejection efficiency.

[0036] Furthermore, regions of the vibrating membrane 103 other than the vibration region 103a may be covered with a protective film 11 or an insulating film 8.

[0037] Next, a method for manufacturing the liquid dispensing head of Embodiment 1 will be described. Figures 6 to 16 illustrate the manufacturing process of the liquid discharge head 1 of Embodiment 1. Figures 6 to 12 and 16(a) are cross-sectional views perpendicular to the direction of arrangement of the nozzles 2, and (b) is a view from the nozzle. Figures 13 to 15 are also cross-sectional views perpendicular to the direction of arrangement of the nozzles 2.

[0038] First, as shown in Figure 6, a vibrating film 103 is deposited on the flow channel substrate 100, which is a Si substrate. Alternatively, a CMOS can be embedded in the flow channel substrate 100 as a drive device for driving the piezoelectric element 5. If a CMOS is embedded in the flow channel substrate 100, the vibrating film 103 is deposited on an SOI (Silicon on Insulator) substrate, where SiO2 is sandwiched between Si layers. The CMOS refers to a drive circuit including transistors and resistors. By fabricating the CMOS within the flow channel substrate 100, the mounting process for a separate drive circuit can be reduced, and the area of ​​the external connection can be reduced. Therefore, the actuator 110 can be miniaturized.

[0039] The CMOS and its wiring layer are formed by methods such as the damascene process, in which SiO2 is deposited and patterned to create grooves, wiring metal is embedded in the grooves, and then covered with SiO2, and the surface is planarized by CMP polishing. By repeating the above SiO2 deposition and patterning, a three-dimensional fine wiring structure can be constructed. The above wiring layer connects the CMOS to the lead wires 9a and 9b drawn out from the piezoelectric element 5, and also connects the CMOS to the electrical connection pad 6.

[0040] The material used for the vibrating film 103 deposited on the channel substrate 100 can be metal oxides such as SiO2, SiN, or ZrO, semiconductors such as SiC or GaAs, or resins. To increase the displacement of the vibrating film 103, a material with a low Young's modulus is desirable, and considering the difference in coefficient of thermal expansion between the vibrating film 103 and the channel substrate 100, SiO2, which has a relatively small difference, is desirable as the material for the vibrating film 103. Furthermore, from a cost perspective, SiO2 is also desirable as the material for the vibrating film 103.

[0041] Next, as shown in Figure 7, a first electrode layer, a piezoelectric layer, and a second electrode layer are deposited on the vibrating film 103, and then they are molded into a suitable shape to form a piezoelectric element 5 consisting of a first electrode 51, a piezoelectric film 52, and a second electrode 53. Sputtering is generally used to deposit the first and second electrode layers. For depositing the piezoelectric layer, sputtering or sol-gel methods are used. However, if the channel substrate 100 incorporates a CMOS and a wiring layer, the sol-gel method requires a high deposition temperature, which may damage them. Therefore, it is preferable to deposit the piezoelectric layer using sputtering.

[0042] The first electrode layer, piezoelectric layer, and second electrode layer are processed by photolithography and etching to form the first electrode 51, piezoelectric film 52, and second electrode 53 in the desired shape. There are two types of etching: wet etching and dry etching. Dry etching is preferred because it can suppress corrosion of the electrodes 51, 53 and the piezoelectric film 52. Since residue tends to remain after dry etching, a cleaning step may be added after molding to remove the residue.

[0043] The first electrode 51 and the second electrode 53 are preferably made of metals with low electrical resistance and low reactivity, such as Pt, Ir, and Mo. Various materials can be used as piezoelectric materials to constitute the piezoelectric film 52, including PZT. However, when CMOS and wiring layers are embedded in the flow channel substrate 100 to improve density, a piezoelectric material with a deposition temperature of 450°C or lower is desirable in order to avoid damaging them. AlN is an example of a piezoelectric material with a deposition temperature of 450°C or lower.

[0044] Furthermore, using AlN as the piezoelectric material offers the following advantages. Specifically, the piezoelectric properties can be improved by aligning the crystal orientation of the piezoelectric film 52, but to control this orientation, an orientation control layer is required between the vibrating film 103 and the first electrode 51. When the piezoelectric material of the piezoelectric film 52 is AlN, using AlN as the orientation control layer allows the lattice constant of the first electrode 51, which is made of Mo, to approach that of AlN. As a result, the crystal orientation of the piezoelectric film 52 is aligned, and the piezoelectric properties can be improved.

[0045] After forming the first electrode 51, piezoelectric film 52, and second electrode 53, an insulating film 8 is formed by film deposition as shown in Figure 8. As mentioned above, the insulating film 8 should have a low Young's modulus and a coefficient of thermal expansion close to that of the constituent material, similar to the vibrating film 103. Therefore, it is preferable to use the same SiO2 as the vibrating film 103. However, a very thin metal oxide or nitride may be deposited to improve reliability. Examples of metal oxides include oxides of tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W). Examples of nitrides include nitrides of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W). Furthermore, the insulating film 8 may contain multiple types of the above-mentioned oxides and nitrides.

[0046] After forming the insulating film 8, a first contact 7a and a second contact 7b with hole shapes are formed in the insulating film 8 by photolithography and etching. In addition, the region of the insulating film 8 other than the area covering the piezoelectric element 5 is removed by etching to avoid an increase in the Young's modulus of the vibrating film 103.

[0047] Next, as shown in Figure 9, the first lead wire 9a and the second lead wire 9b are formed. In this step, the first lead wire 9a is electrically connected to the first electrode 51 via the first contact 7a, and the second lead wire 9b is electrically connected to the second electrode 53 via the second contact 7b. The material for each lead wire 9a and 9b is generally Al, but AlCu alloy or a precious metal film may be used to improve reliability due to its resistance to electromigration. The first lead wire 9a and the second lead wire 9b are formed by dry etching, similar to the piezoelectric element.

[0048] Next, as shown in Figure 10, the portion of the insulating film 8 covering the second electrode 53 is removed by etching, forming an insulating film opening 8a in the central part of the second electrode 53. Thus, in Embodiment 1, the insulating film opening 8a is formed by removing the portion of the insulating film 8 covering the second electrode 53 after the first lead wire 9a and second lead wire 9b have been formed. This is because if the insulating film opening 8a were formed before the lead wires 9a and 9b were formed, the second lead wire 9b would be deposited on the nozzle side of the second contact 7b, and there would be a risk that the second lead wire 9b would come into contact with the second electrode 53 at locations other than the second contact 7b. It would be difficult to remove the portion of the second lead wire 9b that has come into contact with the second electrode 53 at locations other than the second contact 7b.

[0049] After forming the first lead wire 9a and the second lead wire 9b, the portion of the insulating film 8 covering the second electrode 53 is removed to form the insulating film opening 8a. This makes it easy to remove the second lead wire that has been deposited on the nozzle side of the second contact 7b, and to easily shape the second lead wire 9b into the desired shape.

[0050] Next, as shown in Figure 11, a moisture-resistant protective film 11 is formed. As the material for the protective film, in addition to SiN, which is widely used as a moisture-resistant film for semiconductors, metal oxides of Al (aluminum), Ta (tantalum), Nb (niobium), Ti (titanium), Hf (hafnium), Zr (zirconium), and W (tungsten) that are easy to form dense films with atomic layer deposition (ALD) can be used. The protective film 11 may also be a metal nitride of Al (aluminum), Ta (tantalum), Nb (niobium), Ti (titanium), Hf (hafnium), Zr (zirconium), or W (tungsten). Furthermore, it may contain multiple types of the above metal oxides and nitrides.

[0051] Next, as shown in Figure 12, the protective film 11 is removed by etching, except for the portion covering the piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b. In addition, the portion of the protective film 11 covering the end of the first lead wire 9a (the end located on one end of the head) and the end of the second lead wire 9b (the end located on the other end of the head) is removed to form electrical connection pads 6 at both ends of the head. Through the above process, it becomes possible to drive the piezoelectric element 5.

[0052] Next, as shown in Figure 13, a nozzle forming portion 111 for forming the nozzle 2 is deposited. The nozzle forming portion 111 is deposited by spin coating. As the material for the nozzle forming portion 111, it is preferable to use a resin that can be coated by spin coating, and from the viewpoint of chemical resistance, SU8 or BCB is preferable. Next, the nozzle 2 shown in Figure 14 and the pad opening 10 shown in Figure 15 are formed by etching. The etching of the nozzle 2 and the pad opening 10 is dry etching. Through the above steps, a nozzle vibration type actuator 110 is obtained.

[0053] Next, as shown in Figure 16, the flow channel substrate 100 is processed by Si etching to form multiple circular pressurized liquid chambers 4. The pressurized liquid chambers 4 are formed using the Bosch process, a type of dry etching, due to its high controllability in terms of dimensions and cross-sectional shape. After that, the liquid discharge head 1 shown in Figure 1 is formed by joining a frame member 120 with a common liquid chamber 3 formed thereon to the back surface of the flow channel substrate 100.

[0054] The above describes an embodiment in which the actuator of the present invention is applied to a liquid discharge head using a nozzle plate vibration method. However, the actuator of the present invention can also be applied to a unimorph type piezo head (which discharges liquid by vibrating the surface opposite to the surface having the nozzle of the pressurized liquid chamber).

[0055] Figure 17 is a schematic diagram of the liquid discharge head 1A of Embodiment 2, in which the actuator of the present invention is applied to a unimorph type piezo head. As shown in Figure 17, the liquid discharge head 1A of Embodiment 2 includes a nozzle plate 130 on which a nozzle 2 is formed, a flow path substrate 100 equipped with a pressurized liquid chamber 4, an actuator 110, and a frame member 120.

[0056] The actuator 110 has a vibrating membrane 103 and a piezoelectric element 5. The vibrating membrane 103 is formed on the side of the flow channel substrate 100 opposite to the side to which the nozzle plate 130 is joined, and the vibrating membrane 103 constitutes a counter wall facing the nozzle forming wall of the pressurized liquid chamber 4 where the nozzle 2 is formed.

[0057] Similar to Embodiment 1, the portion of the first electrode 51 of the piezoelectric element 5 where the piezoelectric film 52 is not laminated, the portion of the piezoelectric film 52 where the second electrode 53 is not laminated, and the end of the second electrode 53 are covered by the insulating film 8. Also similar to Embodiment 1, the first electrode 51 and the first lead wire 9a are electrically connected via a first contact 7a provided in the insulating film 8, and the second electrode 53 and the second lead wire 9b are electrically connected via a second contact 7b provided in the insulating film 8. The first lead wire 9a, drawn from the first electrode 51, extends to one end of the head, with its end exposed to the outside to form an electrical connection pad 6. The second lead wire 9b, drawn from the second electrode 53, extends to the other end of the head, with its end exposed to the outside to form an electrical connection pad 6.

[0058] Similar to Embodiment 1, the piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b are all covered by a moisture-proof protective film 11. The piezoelectric element 5 is covered by a frame member 120, and the piezoelectric element 5 is protected by the frame member 120. The frame member 120 is bonded to the protective film 11 with an adhesive.

[0059] In the configuration shown in Figure 17, the insulating film 8 on the central side of the second electrode 53 of the piezoelectric element 5 is removed, and an insulating film opening 8a is formed in the central part of the second electrode 53, so that a part of the piezoelectric element 5 is not covered by the insulating film 8. As a result, the rigidity of the piezoelectric element 5 can be reduced compared to a configuration in which the insulating film 8 and protective film 11 cover the entire piezoelectric element 5, and the vibration displacement of the piezoelectric element 5 can be increased. As a result, the droplet ejection efficiency can be improved.

[0060] Furthermore, the piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b are all covered by a moisture-resistant protective film 11. This prevents the formation of interfaces between other films and the protective film 11 near the piezoelectric element 5 and near each lead wire 9a, 9b, and effectively suppresses corrosion of each lead wire 9a, 9b and each electrode 51, 53 of the piezoelectric element 5 due to moisture. As a result, the actuator 110 can be driven stably over a long period of time, and a highly reliable liquid dispensing head can be obtained.

[0061] In this second embodiment as well, the insulating film opening 8a is formed after the second lead wiring by removing the insulating film 8 on the central side of the second electrode 53 of the piezoelectric element 5. This makes it possible to easily shape the second lead wiring 9b into the desired shape, similar to the first embodiment.

[0062] Furthermore, in Embodiment 2, the insulating film 8 is removed by etching except around the piezoelectric element 5, forming a region in the vibration region 103a that constitutes the opposing wall facing the nozzle forming wall of the vibrating film 103 that is not covered by the insulating film 8. This reduces the rigidity of the vibration region 103a, allowing the vibration region 103a to be easily vibrated by the displacement of the piezoelectric element 5. As a result, vibration efficiency can be increased compared to a configuration in which the entire vibration region 103a is covered by the insulating film 8, and droplet ejection efficiency can be increased.

[0063] The protective film 11 is also removed by etching except around the piezoelectric element 5, the first lead wire 9a, and the second lead wire 9b, forming areas in the vibration region 103a of the vibrating film 103 that are not covered by the protective film 11. This reduces the rigidity of the vibration region 103a, allowing it to be easily vibrated by the displacement of the piezoelectric element 5. As a result, vibration efficiency can be increased compared to a configuration in which the entire vibration region 103a is covered by the protective film 11, and droplet ejection efficiency can be improved.

[0064] Next, an example of a liquid dispensing apparatus according to the present invention will be described with reference to Figures 18 and 19. Figure 18 is a schematic diagram illustrating a printing apparatus, which is an inkjet recording apparatus used as a liquid ejection device in this embodiment. Figure 19 is a plan view illustrating an example of a head unit of the printing apparatus according to this embodiment.

[0065] The printing apparatus 500, which is a device that discharges this liquid, includes a loading means 501 for loading the continuous body 510, and a guiding and transporting means 503 for guiding and transporting the continuous body 510 loaded from the loading means 501 to the printing means 505. The printing apparatus 500 also includes a printing means 505 for printing an image by discharging liquid onto the continuous body 510, a drying means 507 for drying the continuous body 510, and an unloading means 509 for unloading the continuous body 510.

[0066] The continuous body 510 is fed out from the main winding roller 511 of the loading means 501, guided and transported by the rollers of the loading means 501, the guiding and transporting means 503, the drying means 507, and the unloading means 509, and then wound up by the winding roller 591 of the unloading means 509. In the printing means 505, this continuous body 510 is transported on the transport guide member 559 facing the head unit 550, and an image is printed by the liquid discharged from the head unit 550.

[0067] In the printing apparatus 500 of this embodiment, the head unit 550 is equipped with the two head modules 100A and 100B described above in this embodiment on a common base member 552.

[0068] Then, when the direction in which the liquid discharge heads 1 are arranged in a direction perpendicular to the transport direction of head modules 100A and 100B is defined as the head array direction, the head rows 1A1 and 1A2 of head module 100A discharge liquid of the same color. Similarly, the head rows 1B1 and 1B2 of head module 100A are paired, the head rows 1C1 and 1C2 of head module 100B are paired, and the head rows 1D1 and 1D2 are paired, and the required color liquid is discharged from each.

[0069] Next, other examples of printing apparatus as a liquid dispensing device according to the present invention will be described with reference to Figures 20 and 21. Figure 20 is a plan view illustrating the main components of the printing apparatus in this example. Figure 21 is a side view illustrating the main components of the printing apparatus in this example.

[0070] The printing apparatus 500 in this example is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is stretched across the left and right side plates 491A and 491B and holds the carriage 403 in a movable position. The carriage 403 is then reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 stretched between the drive pulley 406 and the driven pulley 407.

[0071] The carriage 403 is equipped with a liquid discharge unit 440 that integrates a liquid discharge head 1 and a head tank 441 according to the present invention. The liquid discharge head 1 discharges liquids of various colors, such as yellow (Y), cyan (C), magenta (M), and black (K). The liquid discharge head 1 is also mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and with the discharge direction facing downward. The liquid discharge head 1 is connected to a liquid circulation device, and the required color of liquid is circulated and supplied.

[0072] The printing apparatus 500 is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412. The transport belt 412 picks up the paper 410 and transports it to a position facing the liquid discharge head 1. This transport belt 412 is an endless belt and is stretched between a transport roller 413 and a tension roller 414. Pickup can be performed by electrostatic attraction or air suction. The transport belt 412 moves in a circular motion in the sub-scanning direction as the transport roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0073] Furthermore, a maintenance and recovery mechanism 420 for maintaining and restoring the liquid discharge head 1 is positioned on one side of the carriage 403 in the main scanning direction, next to the transport belt 412. The maintenance and recovery mechanism 420 consists of, for example, a cap member 421 that caps the nozzle surface of the liquid discharge head 1, and a wiper member 422 that wipes the nozzle surface. The main scanning movement mechanism 493, the maintenance and recovery mechanism 420, and the transport mechanism 495 are mounted on a housing that includes side plates 491A, 491B, and a back plate 491C.

[0074] In the printing apparatus 500 configured in this way, the paper 410 is fed onto the transport belt 412 and held in place, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412. Then, by moving the carriage 403 in the main scanning direction and driving the liquid ejection head 1 in accordance with the image signal, liquid is ejected onto the stationary paper 410 to form an image.

[0075] Next, another example of the liquid dispensing unit according to the present invention will be described with reference to Figure 22. Figure 22 is a plan view illustrating the main components of another example of a liquid dispensing unit.

[0076] The liquid discharge unit 440 consists of a housing portion comprising side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid discharge head 1, which are components of the device that discharges the liquid.

[0077] Furthermore, a liquid dispensing unit can also be configured by attaching the aforementioned maintenance and recovery mechanism 420 to, for example, the side plate 491B of the liquid dispensing unit 440.

[0078] Next, yet another example of the liquid dispensing unit according to the present invention will be described with reference to Figure 23. Figure 23 is a front view illustrating yet another example of a liquid dispensing unit.

[0079] This liquid discharge unit 440 consists of a liquid discharge head 1 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

[0080] The flow path component 444 is located inside the cover 442. A head tank 441 can be included instead of the flow path component 444. Furthermore, a connector 443 for electrical connection to the liquid discharge head 1 is provided on the upper part of the flow path component 444.

[0081] In this application, the discharged liquid is not particularly limited as long as it has a viscosity and surface tension that allows it to be discharged from the head, but it is preferable that its viscosity becomes 30 mPa·s or less at room temperature and atmospheric pressure, or when heated or cooled. More specifically, it is a solution, suspension, emulsion, etc., containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a functional material such as a surfactant, a biocompatible material such as DNA, amino acids or proteins, calcium, or an edible material such as a natural pigment. These can be used, for example, in inkjet inks, surface treatment liquids, liquids for forming components of electronic elements and light-emitting elements or electronic circuit resist patterns, and material liquids for 3D molding.

[0082] The energy source for discharging liquid includes piezoelectric actuators (multilayer piezoelectric elements and thin-film piezoelectric elements), thermal actuators using electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a diaphragm and a counter electrode.

[0083] A "liquid discharge unit" is a liquid discharge head with integrated functional components and mechanisms, and includes an assembly of parts related to liquid discharge. For example, a "liquid discharge unit" may include a combination of a liquid discharge head with at least one of the following components: a head tank, carriage, supply mechanism, maintenance and recovery mechanism, main scanning movement mechanism, and liquid circulation device.

[0084] Here, integration includes, for example, cases where the liquid dispensing head and functional components or mechanisms are fixed to each other by fastening, bonding, engaging, etc., or where one is held movably relative to the other. Furthermore, the liquid dispensing head and functional components or mechanisms may be configured to be detachable from each other.

[0085] For example, some liquid dispensing units have a liquid dispensing head and head tank integrated into one unit. Others have a liquid dispensing head and head tank integrated into one unit, connected to each other by tubes or similar means. In these liquid dispensing units, a unit including a filter can also be added between the head tank and the liquid dispensing head.

[0086] Additionally, some liquid dispensing units have an integrated liquid dispensing head and carriage.

[0087] Furthermore, some liquid dispensing units integrate the liquid dispensing head and the scanning mechanism by movably holding the liquid dispensing head in a guide member that constitutes part of the scanning mechanism. Others integrate the liquid dispensing head, carriage, and main scanning mechanism.

[0088] Furthermore, some liquid dispensing units integrate the liquid dispensing head, carriage, and maintenance / recovery mechanism by fixing a cap component, which is part of the maintenance / recovery mechanism, to a carriage to which the liquid dispensing head is attached.

[0089] Furthermore, some liquid discharge units have a head tank or a liquid discharge head to which flow path components are attached, to which a tube is connected, integrating the liquid discharge head and the supply mechanism. Through this tube, the liquid from the liquid storage source is supplied to the liquid discharge head.

[0090] The main scanning movement mechanism shall include the guide member alone. The supply mechanism shall also include the tube alone and the loading section alone.

[0091] Here, the "liquid dispensing unit" is described in combination with a liquid dispensing head, but the "liquid dispensing unit" also includes a head module or head unit that includes the liquid dispensing head mentioned above, as well as the functional components and mechanisms described above, all integrated together.

[0092] "Liquid dispensing devices" include devices that have a liquid dispensing head, liquid dispensing unit, head module, head unit, etc., and drive the liquid dispensing head to dispense liquid. Liquid dispensing devices include not only devices that can dispense liquid onto surfaces to which liquid can adhere, but also devices that dispense liquid into air or into liquid.

[0093] This "liquid dispensing device" may also include means for feeding, transporting, and dispensing paper onto materials to which liquid can adhere, as well as pre-treatment devices, post-treatment devices, etc.

[0094] For example, "devices that dispense liquids" include image forming machines, which dispense ink to form images on paper, and three-dimensional molding machines, which dispense molding liquid into a powder layer formed in layers to create three-dimensional objects.

[0095] Furthermore, "devices that dispense liquid" are not limited to those that visualize meaningful images such as letters or figures through the dispensed liquid. For example, devices that form patterns that do not have meaning in themselves, or devices that create three-dimensional images, are also included.

[0096] The term "materials to which liquid can adhere" above refers to materials to which liquid can adhere, at least temporarily, including materials that adhere and solidify, or materials that adhere and penetrate. Specific examples include recording media such as paper, recording paper, film, and cloth; electronic components such as electronic circuit boards and piezoelectric elements; powder layers; organ models; and inspection cells. Unless otherwise specified, it includes all materials to which liquid can adhere.

[0097] The materials referred to as "materials to which liquid can adhere" above include paper, thread, fibers, fabrics, leather, metal, plastic, glass, wood, ceramics, etc., as long as liquid can adhere to them, even temporarily.

[0098] Furthermore, "liquid dispensing devices" include devices in which the liquid dispensing head and the surface to which the liquid can adhere move relative to each other, but are not limited to these. Specific examples include serial-type devices in which the liquid dispensing head moves, and line-type devices in which the liquid dispensing head does not move.

[0099] Furthermore, other types of "liquid dispensing devices" include processing liquid coating devices that dispense processing liquid onto the surface of paper for purposes such as modifying the paper's surface. There are also spray granulation devices that granulate fine particles of raw materials by spraying a compositional liquid, in which raw materials are dispersed in a solution, through a nozzle.

[0100] In this application, the terms image formation, recording, printing, copying, printing, and shaping are all considered synonymous.

[0101] Furthermore, although the above describes an example in which the actuator of the present invention is applied to a liquid discharge head, the actuator of the present invention can also be applied to micropumps, for example, as described in Japanese Patent Application Publication No. 2012-253087 and Japanese Patent Application Publication No. 2014-030008.

[0102] The above is just one example; each of the following embodiments produces its own unique effects. (Aspect 1) In an actuator 110, the piezoelectric element 5 comprises a vibrating membrane 103 laminated on a substrate such as a flow channel substrate 100 in which a liquid chamber such as a pressurized liquid chamber 4 is formed and which constitutes a part of the wall surface of the liquid chamber; a first electrode 51 laminated on the side of the vibrating membrane 103 opposite to the side that constitutes the wall surface of the liquid chamber; a piezoelectric part such as a piezoelectric film 52 laminated on the first electrode 51; and a second electrode 53 laminated on the piezoelectric part; a wiring part such as a second lead wire 9b that covers the piezoelectric element and is drawn out from at least the second electrode 53; an insulating film 8 that electrically insulates the piezoelectric part and the first electrode 51; and a protective film 11 that protects the piezoelectric element 5 from moisture. According to this, the vibrational displacement of the piezoelectric element can be increased compared to a design where the entire piezoelectric element is covered by an insulating film and a protective film. Furthermore, since the protective film covers the entire piezoelectric element, it can effectively protect the piezoelectric element from moisture and effectively suppress corrosion and short circuits.

[0103] (Aspect 2) In Embodiment 1, the insulating film 8 includes at least one oxide of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W), or at least one nitride of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W). According to this, the piezoelectric element 5 can be electrically insulated effectively.

[0104] (Aspect 3) In embodiment 1 or 2, the protective film 11 has electrical insulating properties. According to this, the area of ​​the piezoelectric element 5 that is not covered by the insulating film 8 can be electrically insulated by the protective film 11.

[0105] (Aspect 4) In embodiment 3, the protective film 11 comprises at least one oxide of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W). According to this, the piezoelectric element 5 can be effectively protected from moisture and electrically insulated.

[0106] (Appendix 5) In any of embodiments 1 to 4, the protective film 11 also covers the wiring portion such as the first lead wire 9a drawn out from the first electrode 51 and the wiring portion such as the second lead wire 9b drawn out from the second electrode 53. According to this, the piezoelectric element 5 and the wiring section can be protected from moisture.

[0107] (Aspect 6) In any of embodiments 1 to 5, at least the second electrode 53 has a region that is not covered by the insulating film 8. According to this, since the piezoelectric element 5 is displaced in the stacking direction of the first electrode 51, the piezoelectric portion, and the second electrode 53, the vibrational displacement of the piezoelectric element can be improved by providing a region of the second electrode 53 that is not covered by the insulating film 8.

[0108] (Aspect 7) In embodiment 6, the insulating film 8 covers the portion of the first electrode 51 where the piezoelectric film 52 or other piezoelectric elements are not laminated, the portion of the piezoelectric element where the second electrode 53 is not laminated, and the end of the second electrode 53. According to this, as described in the embodiment, the wiring parts such as the lead wires 9a and 9b drawn out from the piezoelectric element 5 can be electrically isolated from the piezoelectric element 5.

[0109] (Pattern 8) In any of embodiments 1 to 7, the vibration region 103a that constitutes a part of the wall surface of a liquid chamber such as the pressurized liquid chamber 4 of the vibrating membrane 103 has an insulating film uncovered portion 8b that is not covered by the insulating film 8. According to this, compared to the case where the entire vibration region 103a is covered with the insulating film 8, as described in the embodiment, the rigidity of the vibration region 103a can be reduced, and the vibrating membrane 103 can be vibrated effectively.

[0110] (Aspect 9) In any of embodiments 1 to 8, the vibration region 103a that constitutes a part of the wall surface of the liquid chamber of the pressurized liquid chamber 4 of the vibrating membrane 103 has a protective film uncovered portion 11a that is not covered by the protective film 11. According to this, compared to the case where the entire vibration region 103a is covered by the protective film 11, as described in the embodiment, the rigidity of the vibration region 103a can be reduced, and the vibrating membrane 103 can be vibrated effectively.

[0111] (Aspect 10) In a liquid discharge head 1 equipped with an actuator, which discharges liquid from a liquid chamber such as a pressurized liquid chamber 4 from a nozzle 2, any actuator from embodiment 1 to 9 was used as the actuator. According to this, as described in the embodiment, the droplet discharge efficiency can be increased.

[0112] (Aspect 11) In embodiment 10, the actuator is provided with a nozzle 2, and the vibrating membrane 103 constitutes a nozzle forming wall in which the nozzle 2 of a liquid chamber such as a pressurized liquid chamber 4 is formed. According to this, as described in the embodiment, the nozzle forming wall can be vibrated to eject droplets from the nozzle 2.

[0113] (Aspect 12) In embodiment 10, the vibrating membrane 103 constitutes a counter wall facing the nozzle forming wall of a liquid chamber such as the pressurized liquid chamber 4, where the nozzle 2 is formed. According to this, as explained using Figure 17, the opposing wall can be vibrated to eject droplets from the nozzle 2.

[0114] (Aspect 13) In a liquid dispensing device equipped with a liquid dispensing head 1, any of the liquid dispensing heads from embodiments 10 to 12 was used as the liquid dispensing head. This method can improve the droplet ejection efficiency.

[0115] (Aspect 14) In an actuator 110 comprising a vibrating membrane 103 laminated on a substrate such as a flow channel substrate 100 in which a liquid chamber such as a pressurized liquid chamber 4 is formed and which constitutes a part of the wall surface of the liquid chamber, a piezoelectric element 5 composed of a first electrode 51 laminated on the side of the vibrating membrane 103 opposite to the side that constitutes the wall surface of the liquid chamber, a piezoelectric part such as a piezoelectric film 52 laminated on the first electrode 51, and a second electrode 53 laminated on the piezoelectric part, a wiring part such as a second lead wire 9b that covers the piezoelectric element 5 and is drawn out from at least the second electrode 53, an insulating film 8 that electrically insulates the piezoelectric part and the first electrode 51, and a protective film 11 that protects the piezoelectric element 5 from moisture, in a method for manufacturing the actuator, the piezoelectric element 5 is covered with the insulating film 8, then the wiring part such as a first lead wire 9a drawn out from the first electrode and the wiring part such as a second lead wire drawn out from the second electrode are formed, after the wiring part is formed a part of the insulating film covering the piezoelectric element is removed, and after the insulating film 8 is removed the protective film 11 is formed. According to this, as described in the embodiment, the wiring section can be easily shaped to the desired form. [Explanation of Symbols]

[0116] 1: Liquid dispensing head 2: Nozzle 3: Common liquid chamber 4: Pressurized liquid chamber 5: Piezoelectric element 6: Electrical connection pad 7a: First Contact 7b: Second Contact 8: Insulating film 8a: Insulator opening 8b: Uncovered portion of insulating film 9a: First pullout wiring 9b: Second lead wire wiring 10: Pad opening 11:Protective film 11a: Uncovered portion of protective film 51:First electrode 52: Piezoelectric film 53:Second electrode 100: Flow channel substrate 103: Vibrating membrane 103a: Vibration area 110: Actuator 111: Nozzle forming section 120: Frame component 130: Nozzle plate 401: Guide member 403: Carriage 405: Main scanning motor 408: Timing belt 412: Conveyor belt 413: Conveyor roller 414: Tension Roller 416: Sub-scanning motor 417: Timing belt 420: Maintenance and recovery mechanism 421: Cap component 422: Wiper component 440: Liquid Dispensing Unit 441: Head Tank 444: Flow channel component 456: Tube 493: Main scanning movement mechanism 495: Conveying mechanism 500:Printing device 501: Delivery method 503: Guidance and transport means 505:Printing means 507 :Drying means 509:Export means 550: Head Unit [Prior art documents] [Patent Documents]

[0117] [Patent Document 1] Japanese Patent Publication No. 2023-133007

Claims

1. A vibrating membrane is laminated on a substrate in which a liquid chamber is formed, and which constitutes a part of the wall surface of the liquid chamber, A piezoelectric element comprising a first electrode laminated on the side of the vibrating membrane opposite to the side constituting the wall of the liquid chamber, a piezoelectric portion laminated on the first electrode, and a second electrode laminated on the piezoelectric portion, Covering the piezoelectric element, an insulating film is provided to electrically insulate the piezoelectric element from a wiring portion that extends at least from the second electrode and the piezoelectric portion and the first electrode. An actuator comprising a protective film for protecting the piezoelectric element from moisture, The piezoelectric element has a region that is not covered by the insulating film, The actuator is characterized in that the protective film covers the entire piezoelectric element.

2. In the actuator according to claim 1, The actuator is characterized in that the insulating film contains at least one oxide of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W), or a nitride of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W).

3. In the actuator according to claim 1, The actuator is characterized in that the protective film has electrical insulating properties.

4. In the actuator according to claim 3, The actuator is characterized in that the protective film contains at least one oxide of silicon (Si), tantalum (Ta), niobium (Nb), titanium (Ti), hafnium (Hf), zirconium (Zr), and tungsten (W).

5. In the actuator according to claim 1, The actuator is characterized in that the protective film also covers the wiring portion drawn out from the first electrode and the wiring portion drawn out from the second electrode.

6. In the actuator according to claim 1, An actuator characterized in that at least the second electrode has a region that is not covered by the insulating film.

7. In the actuator according to claim 6, The actuator is characterized in that the insulating film covers the portion of the first electrode where the piezoelectric portion is not laminated, the portion of the piezoelectric portion where the second electrode is not laminated, and the end of the second electrode.

8. In the actuator according to claim 1, The actuator is characterized in that the vibration region constituting a part of the wall surface of the liquid chamber of the vibrating membrane has an insulating film uncovered portion that is not covered by the insulating film.

9. In the actuator according to claim 1, The actuator is characterized in that a portion of the vibration region constituting a part of the wall surface of the liquid chamber of the vibrating membrane has a protective film uncovered portion that is not covered by the protective film.

10. Equipped with an actuator, In a liquid discharge head that discharges liquid from a liquid chamber through a nozzle using the actuator, A liquid discharge head characterized in that the actuator described in claim 1 is used as the actuator.

11. In the liquid dispensing head according to claim 10, The actuator is provided with the nozzle, The liquid discharge head is characterized in that the vibrating membrane constitutes the nozzle forming wall of the liquid chamber in which the nozzle is formed.

12. In the liquid dispensing head according to claim 10, The liquid discharge head is characterized in that the vibrating membrane constitutes an opposing wall facing the nozzle forming wall of the liquid chamber where the nozzle is formed.

13. In a device for dispensing liquid equipped with a liquid dispensing head, A liquid dispensing device characterized in that the liquid dispensing head used is the liquid dispensing head described in claim 10.

14. A vibrating membrane is laminated on a substrate in which a liquid chamber is formed, and which constitutes a part of the wall surface of the liquid chamber, A piezoelectric element comprising a first electrode laminated on the side of the vibrating membrane opposite to the side constituting the wall of the liquid chamber, a piezoelectric portion laminated on the first electrode, and a second electrode laminated on the piezoelectric portion, Covering the piezoelectric element, an insulating film is provided to electrically insulate the piezoelectric element from a wiring portion that extends at least from the second electrode and the piezoelectric portion and the first electrode. A method for manufacturing an actuator comprising a protective film for protecting the piezoelectric element from moisture, After covering the piezoelectric element with the insulating film, a wiring portion extending from the first electrode and a wiring portion extending from the second electrode are formed. After forming the wiring portion, a portion of the insulating film covering the piezoelectric element is removed. A method for manufacturing an actuator, characterized by forming the protective film after removing the insulating film.

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