JP2006116953A - Liquid ejecting apparatus and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejecting apparatus which reduces a parts count by omitting a wiring board such as an FPC and can also simplify a manufacturing process, and to provide a manufacturing method therefor. <P>SOLUTION: An inkjet head 1 has both a plurality of discrete ink passages 2 including nozzles 20 and pressure chambers 16, and a piezoelectric actuator 3. The discrete ink passage 2 is formed by a plurality of layered sheets of plates. The piezoelectric actuator 3 is arranged between a pressure chamber plate 13 which forms a plurality of the pressure chambers 16 and a nozzle plate 14 which is formed of an insulating material and forms the nozzles 20. A plurality of wiring parts 34 respectively connected to a plurality of discrete electrodes 32 are formed at a face of the piezoelectric actuator 3 side of the nozzle plate 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid and a method of manufacturing the same.

  The liquid ejecting apparatus that ejects liquid includes, for example, a nozzle that ejects liquid, a pressure chamber that communicates with the nozzle, and an actuator that changes the volume of the pressure chamber, and the actuator applies pressure to the liquid in the pressure chamber. Some are configured to apply and eject liquid from a nozzle. Among these, for example, Patent Document 1 describes an inkjet head that ejects ink from nozzles. The inkjet head actuator includes a plurality of piezoelectric sheets provided to cover the plurality of pressure chambers, and a plurality of individual electrodes formed on the upper surface of the uppermost piezoelectric sheet so as to face the plurality of pressure chambers, respectively. And a common electrode formed on the lower surface of the uppermost piezoelectric sheet. A plurality of individual electrodes formed on the upper surface of the piezoelectric sheet are electrically connected to a flexible printed wiring board (FPC) by solder or the like at the land portion, and this FPC is further connected to a driver IC (driving device). . When a drive voltage is selectively applied from the driver IC to the plurality of individual electrodes via the FPC, the portion of the piezoelectric sheet sandwiched between the individual electrodes and the common electrode is deformed, and the pressure chamber Pressure is applied to the ink.

JP 2004-136663 A

  In the ink jet head described in Patent Document 1, a wiring member such as an FPC that electrically connects a plurality of individual electrodes and a driver IC is required, which increases the manufacturing cost. In recent years, attempts have been made to arrange a plurality of pressure chambers with higher density in order to satisfy both the demands for improvement in image quality and downsizing of the inkjet head. Then, it is necessary to arrange a plurality of individual electrodes respectively opposed to the plurality of pressure chambers at high density. However, it is very difficult to connect the land portions of the plurality of densely arranged individual electrodes and the FPC with solder or the like. Further, the connection structure tends to be complicated in order to increase the reliability of the electrical connection, and the manufacturing process is complicated, which is disadvantageous in terms of manufacturing cost.

  An object of the present invention is to provide a liquid ejecting apparatus capable of reducing the number of parts by omitting a wiring member such as an FPC and simplifying the manufacturing process, and a manufacturing method thereof.

Means for Solving the Problems and Effects of the Invention

  According to the first aspect of the present invention, a plurality of liquid flow paths each including a plurality of nozzles for ejecting liquid and a plurality of pressure chambers communicating with the plurality of nozzles, respectively, and the volumes of the plurality of pressure chambers A liquid ejecting apparatus including an actuator that selectively changes the pressure channel, wherein the liquid flow path is formed by a plurality of stacked plates, and the plurality of pressure chambers included in the plurality of plates The actuator is disposed between a pressure chamber plate to be formed and a nozzle plate having insulating properties at least on a surface facing the pressure chamber plate, and the actuator includes the plurality of pressures. A diaphragm covering the chamber, a piezoelectric layer provided on the surface of the diaphragm opposite to the plurality of pressure chambers, and the plurality of pressures on the surface of the piezoelectric layer opposite to the diaphragm. And a plurality of individual electrodes formed at positions facing each other, and a plurality of wiring portions respectively connected to the plurality of individual electrodes are formed on the surface of the nozzle plate on the actuator side. An apparatus is provided.

  The liquid ejecting apparatus is configured to eject a liquid from a nozzle by applying pressure to the liquid in the pressure chamber by selectively changing the volumes of the plurality of pressure chambers using an actuator. Here, the plurality of liquid flow paths are formed by a plurality of plates, and an actuator is disposed between a pressure chamber plate and a nozzle plate made of an insulating material included in the plurality of plates. A plurality of wiring portions respectively connected to the plurality of individual electrodes of the actuator are formed on the surface of the nozzle plate on the actuator side. As described above, since the plurality of wiring portions connected to the plurality of individual electrodes are formed on the nozzle plate made of an insulating material, this wiring is provided with the function of a wiring member such as a conventional FPC on the nozzle plate. The members can be omitted, and the number of parts can be reduced to reduce the manufacturing cost of the liquid ejecting apparatus. It is also possible to dispose the drive device on the nozzle plate. Furthermore, at the same time that the nozzle plate is bonded to the actuator, it is possible to electrically connect the plurality of individual electrodes and the plurality of wiring portions, thereby simplifying the manufacturing process.

  In the liquid ejecting apparatus of the present invention, in the first embodiment, the liquid channel may be formed so as to penetrate the actuator. In this case, an actuator can be disposed between the pressure chamber plate and the nozzle plate.

  In the liquid ejecting apparatus according to the aspect of the invention described above, in the piezoelectric layer, a through hole that forms a part of the liquid flow path is formed in the piezoelectric layer, and the liquid penetrates the piezoelectric layer on the inner surface of the through hole. A protective film for preventing this may be formed. This protective film can prevent liquid from penetrating the piezoelectric layer. In particular, when the liquid has conductivity, it is possible to prevent the individual electrodes from being short-circuited by the conductive liquid.

  In the liquid ejecting apparatus according to the aspect of the invention, the nozzle plate may be made of an insulating material having flexibility. Therefore, the nozzle plate can be routed like a flexible FPC or the like, and the degree of freedom of arrangement of the driving device connected to the wiring portion is increased.

  In the liquid ejecting apparatus according to the aspect of the invention, a plurality of recesses may be formed in a portion of the nozzle plate facing the plurality of individual electrodes. Therefore, when the drive voltage is supplied to the individual electrode and the piezoelectric layer is deformed, the deformation of the piezoelectric layer is not hindered by the nozzle plate or the adhesive that bonds the nozzle plate and the piezoelectric layer, and the drive efficiency of the actuator Will improve.

  In the liquid ejecting apparatus according to the aspect of the invention, a plurality of recesses may be formed in a portion of the diaphragm facing the plurality of individual electrodes. Therefore, when the piezoelectric layer is formed with a uniform thickness on the surface of the diaphragm where the recess is formed, a recess corresponding to the recess of the diaphragm is formed in the portion of the piezoelectric layer where the individual electrode is formed. Therefore, even if the drive voltage is supplied to the individual electrode and the piezoelectric layer is deformed, the deformation of the piezoelectric layer is not hindered by the nozzle plate, and the drive efficiency of the actuator is improved.

  In the liquid ejecting apparatus according to the aspect of the invention, the nozzle plate and the piezoelectric layer may be bonded to each other with an anisotropic conductive material having conductivity in a compressed state. In this case, the anisotropic conductive material can simultaneously bond the piezoelectric layer and the nozzle plate and electrically connect the individual electrode and the wiring portion, thereby simplifying the manufacturing process.

  In the liquid ejecting apparatus according to the aspect, the anisotropic conductive material may be compressed and conductive in a connection area between the contact portion of the individual electrode and the terminal portion of the wiring portion in the form. In other areas, the anisotropic conductive material may not have conductivity. The anisotropic conductive material has conductivity in the electrical connection portion of the contact portion of the individual electrode and the terminal portion of the wiring portion, but has no conductivity in the other portions, so a drive voltage was applied to the wiring portion. Sometimes, it is possible to suppress the generation of unnecessary capacitance in the piezoelectric layer due to portions other than the terminal portion of the wiring portion as much as possible, and the driving efficiency of the actuator is improved.

  In the liquid ejecting apparatus according to the aspect of the invention, in the above embodiment, the separation distance between the contact portion of the individual electrode and the terminal portion of the wiring portion is the separation between the nozzle plate and the piezoelectric layer in other portions. It may be smaller than the distance. In this case, it becomes easy to compress only the anisotropic conductive material between the individual electrode and the wiring portion and electrically connect them.

  In the liquid ejecting apparatus according to the aspect of the invention, the plurality of wiring portions may be formed in a region not facing the plurality of nozzles and the plurality of pressure chambers on the surface of the nozzle plate on the actuator side. Good. Since the wiring part is formed in a region that does not face the nozzle, the liquid does not adhere to the wiring part, and in particular, when the liquid has conductivity, it is possible to prevent the wiring parts from being short-circuited. In addition, since the wiring portion is formed in a region that does not face the pressure chamber, the wiring portion does not hinder the deformation of the piezoelectric layer during liquid ejection.

  The liquid ejecting apparatus according to the aspect of the invention may further include a common liquid chamber that communicates with the plurality of pressure chambers, and the common liquid chamber may be disposed on a side opposite to the nozzle with respect to the actuator. . As described above, since the common liquid chamber is arranged on the side opposite to the nozzle, a wide arrangement space of the nozzle can be secured, so that the degree of freedom in arrangement is increased, and the nozzle can be arranged at a higher density.

  In the liquid ejecting apparatus according to the aspect of the invention, the nozzle may be directed downward, and the common liquid chamber may be disposed above the nozzle. In this case, the bubbles mixed in the liquid flow path can be easily discharged to the common liquid chamber side.

  In the liquid ejecting apparatus according to the aspect of the invention, the plurality of pressure chambers may be formed between the actuator and the common liquid chamber. In this case, since the common liquid chamber is formed above the pressure chamber, a wide space for arranging the common liquid chamber can be secured.

  In the liquid ejecting apparatus according to the aspect of the invention, an individual liquid channel that communicates from the common liquid chamber through the plurality of pressure chambers to the nozzle is formed, and the individual liquid channel toward the common liquid chamber side is directed upward. You may incline and arrange so that it may extend. In this case, the individual liquid channel formed in the pressure chamber extends vertically upward toward the upstream side of the liquid flow, so that bubbles mixed in the liquid channel do not stay in the pressure chamber. It is reliably discharged to the common liquid chamber side.

  In the liquid ejecting apparatus of the invention, the flexible insulating material may be polyimide. Polyimide is not only a flexible insulating material, but also has liquid repellency, so that the flow of liquid on the nozzle plate surface is smooth.

  In the liquid ejecting apparatus according to the aspect of the invention, the liquid ejecting apparatus may be an ink jet head. In this case, since the plurality of individual electrodes are not electrically connected to the wiring member such as the FPC by soldering or the like, the individual electrodes can be arranged with high density.

  The ink jet printer of the present invention may include the liquid ejecting apparatus of the present invention. In this case, since a wiring member such as an FPC is not used for the wiring that connects the individual electrodes of the inkjet head and the IC that drives the piezoelectric actuator, the reliability of the electrical connection between them is high.

  The method for manufacturing a liquid ejecting apparatus of the present invention is a method for manufacturing the liquid ejecting apparatus according to the first embodiment, wherein the wiring section is formed on the surface of the nozzle plate that is bonded to the piezoelectric layer. And a bonding step of bonding the nozzle plate to the actuator, and in the bonding step, the terminal portion of the wiring portion is bonded to the contact portion of the individual electrode in a conductive state, and the other than the terminal portion. The nozzle plate portion may be bonded to the piezoelectric layer in an insulating state. In this case, the adhesion of the nozzle plate and the actuator and the electrical connection of the individual electrodes on the actuator side and the wiring part on the nozzle plate side can be performed simultaneously, and the manufacturing process can be simplified. In addition, by bonding the portions other than the terminal portions of the wiring portion to the piezoelectric layer in an insulating state, it is possible to suppress unnecessary capacitance from being generated in the piezoelectric layer as much as possible, and the drive efficiency of the actuator is improved. .

  The manufacturing method of the liquid ejecting apparatus of the present invention includes an attaching step of attaching an anisotropic conductive material to the adhesion surface of the nozzle plate or the piezoelectric layer before the adhering step, and in the adhering step, the individual electrode The anisotropic conductive material adhering to one surface of the contact portion of the wiring portion and the terminal portion of the wiring portion is brought into contact with the other of the contact portion of the individual electrode and the terminal portion of the wiring portion, and the anisotropic of this portion. The nozzle plate may be bonded to the piezoelectric layer by the anisotropic conductive material in other portions while compressing the conductive conductive layer and connecting the individual electrodes and the wiring portion in a conductive state. In this case, since the adhesion between the nozzle plate and the actuator and the electrical connection between the individual electrode and the wiring portion can be performed simultaneously using one kind of anisotropic conductive material, the number of types of adhesive used is reduced. Manufacturing costs can be reduced.

  In the method of manufacturing a liquid ejecting apparatus according to the aspect of the invention, before the bonding step, the diaphragm includes a hole forming step of forming a hole constituting a part of the liquid flow path, and the pressure chamber of the diaphragm. There may be provided a piezoelectric layer forming step of forming the piezoelectric layer only in a region where the hole of the diaphragm is not formed by depositing particles of the piezoelectric material on the opposite surface. In this way, by forming the through hole in the diaphragm and then depositing the particles of the piezoelectric material on the diaphragm, the piezoelectric layer is formed only in the region where the hole is not formed. Through holes can be formed in this piezoelectric layer.

  In the method for manufacturing a liquid ejecting apparatus of the present invention, in the piezoelectric layer forming step, the piezoelectric layer is formed at a position corresponding to the hole of the vibration plate of the piezoelectric layer, and on the inner surface of the through hole constituting a part of the liquid flow path, You may provide the protective film formation process which forms the protective film which prevents a liquid osmose | permeating a piezoelectric layer. In this case, the protective film can prevent the liquid from penetrating into the piezoelectric layer from the inner surface of the through hole. In particular, when the liquid has conductivity, the individual electrodes can be prevented from being short-circuited by the conductive liquid.

  Embodiments of the present invention will be described. The present embodiment is an example in which the present invention is applied to an inkjet head that ejects ink from nozzles. First, the ink jet printer 100 including the ink jet head 1 will be briefly described. As shown in FIG. 1, an inkjet printer 100 includes a carriage 101 that can move in the left-right direction in FIG. 1, a serial inkjet head 1 that is provided on the carriage 101 and that ejects ink onto a recording paper P, A transport roller 102 that transports the recording paper P forward in FIG. 1 is mainly provided. The ink-jet head 1 moves in the left-right direction (scanning direction) in FIG. 1 integrally with the carriage 101, and records from the emission port of the nozzle 20 (see FIGS. 2 to 7) formed on the ink ejection surface on the lower surface thereof. Ink is ejected onto the paper P. Then, the recording paper P recorded by the inkjet head 1 is discharged forward (paper feeding direction) by the transport roller 102.

  Next, the inkjet head 1 will be described with reference to FIGS. The inkjet head 1 is composed of a plurality of stacked plates. The inkjet head 1 includes a plurality of nozzles 20 that eject ink and a plurality of pressure chambers 16 that respectively communicate with the plurality of nozzles 20. A plurality of individual ink flow paths 2 including the piezoelectric actuators 3 that selectively change the volumes of the plurality of pressure chambers 16 are provided.

  As shown in FIG. 3, the plurality of individual ink flow paths 2 are formed by a plurality of plates including the vibration plate 30 and the piezoelectric layer 31 of the piezoelectric actuator 3. The plurality of plates are laminated in the order of the manifold plates 10 and 11, the base plate 12, the pressure chamber plate 13, the vibration plate 30 and the piezoelectric layer 31 of the piezoelectric actuator 3, and the nozzle plate 14. Here, the manifold plates 10, 11, the base plate 12, and the pressure chamber plate 13 are metal plates such as stainless steel, respectively, and ink channels such as the manifold 17 and the pressure chamber 16 described later can be easily formed by etching. . On the other hand, the nozzle plate 14 is formed of a synthetic resin material having flexibility, for example, a polymer synthetic resin material such as polyimide.

  First, plates other than the piezoelectric actuator 3 will be described in order. Manifolds 17 connected to the plurality of pressure chambers 16 are formed on the two manifold plates 10 and 11. As shown in FIGS. 2 and 3, the manifold 17 is formed so as to overlap all of the plurality of pressure chambers 16 in a plan view, and the manifold 17 is provided with ink supply holes 18 from an ink supply source (not shown). Ink is supplied through A filter 19 is provided between the two manifold plates 10 and 11 to remove dust mixed with ink in the manifold 17. A plurality of communication holes 21 are formed in the base plate 12 so that the manifold 17 and the plurality of pressure chambers 16 communicate with each other.

  As shown in FIG. 2, a plurality of pressure chambers 16 arranged along a plane are formed in the pressure chamber plate 13. The plurality of pressure chambers 16 are arranged in two rows in the paper feeding direction (vertical direction in FIG. 2). Each pressure chamber 16 is formed in a substantially elliptical shape in plan view, and is arranged so that the major axis direction thereof is the left-right direction (scanning direction). Each pressure chamber 16 communicates with the manifold 17 via a communication hole 21 formed in the base plate 12 at the right end in FIG.

  A plurality of nozzles 20 directed downward in the vertical direction are formed at positions where the nozzle plate 14 overlaps the left end portions of the plurality of pressure chambers 16 in FIG. As shown in FIGS. 3 to 5, the nozzle plate 14 is formed on the surface opposite to the pressure chamber 16 of the piezoelectric actuator 3 by an adhesive 22 made of an anisotropic conductive material having conductivity in a compressed state. It is glued. The piezoelectric actuator 3 is disposed between the pressure chamber plate 13 and the nozzle plate 14, and the manifold 17, the pressure chamber 16, and the nozzle 20 are disposed on opposite sides of the piezoelectric actuator 3. As described above, since the manifold 17 is arranged on the opposite side to the nozzle 20 with respect to the piezoelectric actuator 3, a region where the nozzle 20 can be arranged is widened, the degree of freedom in arrangement is increased, and the nozzle 20 is arranged at a higher density. Is possible. Further, since the nozzle 20 is directed downward in the vertical direction and the manifold 17 is disposed above the nozzle 20 in the vertical direction, the air bubbles mixed in the individual ink flow path 2 are caused by the buoyancy of the manifold 17 due to its own buoyancy. It becomes easy to move to the manifold 17 side, and it becomes easy to discharge the bubbles to the manifold 17 side. Furthermore, as shown in FIG. 4, the inkjet head 1 is arranged slightly inclined in the direction of arrow a with respect to the surface (horizontal plane) on which the inkjet printer 100 is installed, and the nozzle 20 is directed obliquely downward. If there is, the bubbles in the individual ink flow path 2 are more likely to move to the manifold 17 as indicated by the dashed arrows.

  As described above, when the manifold 17 is arranged above the nozzle 20 in the vertical direction, bubbles mixed in the individual ink flow path 2 can be easily moved to the manifold 17 by the buoyancy. If the individual ink channel 2 is formed so as to extend upward in the vertical direction toward the upstream side of the ink flow, as shown in FIG. To the manifold 17. In other words, if the inkjet head 1 is arranged to be inclined with respect to the horizontal plane, bubbles mixed in the individual ink flow path 2 can be moved to the manifold 17 more reliably.

  The pressure chamber 16 formed in the pressure chamber plate 13 and the nozzle 20 formed in the nozzle plate 14 communicate with each other via through holes 35 and 36 formed in the vibration plate 30 and the piezoelectric layer 31 of the piezoelectric actuator 3, respectively. is doing. Further, on the surface of the nozzle plate 14 on the piezoelectric actuator 3 side, there are formed a plurality of wiring portions 34 respectively connected to the plurality of individual electrodes 32 and extending to one side in the scanning direction (right side in FIG. 2). A driver IC 38 connected to the plurality of wiring portions 34 is disposed on the surface of the plate 14 on which the plurality of wiring portions 34 are formed. The wiring unit 34 and the driver IC 38 will be described in detail later. As shown in FIGS. 3 and 5, an individual ink flow path 2 that extends from the manifold 17 through the pressure chamber 16, through the piezoelectric actuator 3 to the nozzle 20 is formed in the inkjet head 1.

  Next, the piezoelectric actuator 3 will be described. As shown in FIGS. 2 to 7, the piezoelectric actuator 3 includes a vibration plate 30 that covers the lower side of the plurality of pressure chambers 16, and a piezoelectric element provided on the surface of the vibration plate 30 opposite to the plurality of pressure chambers 16. The layer 31 and a plurality of individual electrodes 32 formed at positions facing the plurality of pressure chambers 16 on the surface of the piezoelectric layer 31 opposite to the vibration plate 30.

  The diaphragm 30 is a substantially rectangular metal plate in plan view, and is made of, for example, an iron-based alloy such as stainless steel, a copper-based alloy, a nickel-based alloy, or a titanium-based alloy. The diaphragm 30 is joined to the lower surface of the pressure chamber plate 13 so as to close the plurality of pressure chambers 16. The diaphragm 30 also serves as a common electrode that opposes the plurality of individual electrodes 32 and applies an electric field to the piezoelectric layer 31 between the individual electrodes 32 and the diaphragm 30, and the wiring portion 40 (see FIG. 2). ) Through the ground potential. On the lower surface of the diaphragm 30, a piezoelectric layer 31 mainly composed of lead zirconate titanate (PZT), which is a solid solution and is a ferroelectric substance, is formed of lead titanate and lead zirconate. The piezoelectric layer 31 is continuously formed across the plurality of pressure chambers 16.

  Through holes 35 and 36 constituting a part of the individual ink flow path 2 are formed at positions where the vibration plate 30 and the piezoelectric layer 31 overlap the left end portion of the pressure chamber 16 in FIG. In these through holes 35 and 36, the individual ink flow path 2 penetrates the piezoelectric actuator 3, and the pressure chamber 16 and the nozzle 20 communicate with each other. Here, when the piezoelectric layer 31 is exposed to the individual ink flow path 2 in the through hole 36, the conductive ink penetrates into the piezoelectric layer 31, and the individual electrodes 32 are short-circuited by this ink. There is a risk of it. Therefore, in the ink jet head of the present embodiment, the protective film 37 that prevents the ink flowing through the individual ink flow path 2 from penetrating the piezoelectric layer 31 is formed on the inner surfaces of the through holes 35 and 36. The protective film 37 is made of, for example, silicon oxide or silicon nitride.

  A plurality of individual electrodes 32 having an elliptical planar shape that is slightly smaller than the pressure chamber 16 are formed on the lower surface of the piezoelectric layer 31. Each of the plurality of individual electrodes 32 is formed at a position overlapping the central portion of the corresponding pressure chamber 16 in plan view. The individual electrode 32 is made of a conductive material such as gold. Further, as shown in FIGS. 2 to 5 and 7, the plurality of individual electrodes 32 are formed on the nozzle plate 14 from the longitudinal ends (right ends in FIGS. 2 to 5 and 7), respectively. A plurality of contact portions 32a that are electrically connected to the driver IC 38 through the plurality of wiring portions 34 extend to a region that does not overlap the pressure chamber 16 in plan view. Then, a drive voltage is selectively applied to the plurality of individual electrodes 32 from the driver IC 38 via the plurality of wiring portions 34 and the contact portions 32a.

  Next, the operation of the piezoelectric actuator 3 will be described. When a driving voltage is selectively applied to the plurality of individual electrodes 32 from the driver IC 38, the individual electrodes 32 on the upper side of the piezoelectric layer 31 to which the driving voltage is supplied and the lower side of the piezoelectric layer 31 held at the ground potential. The potentials of the diaphragm 30 as the common electrode are in different states, and an electric field in the vertical direction is generated in the portion of the piezoelectric layer 31 sandwiched between the individual electrode 32 and the diaphragm 30. Then, the portion of the piezoelectric layer 31 directly below the individual electrode 32 to which the drive voltage is applied contracts in the horizontal direction orthogonal to the vertical direction that is the polarization direction. At this time, the diaphragm 30 is deformed so as to protrude toward the pressure chamber 16 as the piezoelectric layer 31 contracts, so that the volume in the pressure chamber 16 decreases and pressure is applied to the ink in the pressure chamber 16. Then, ink is ejected from the nozzle 20 communicating with the pressure chamber 16.

  By the way, the nozzle plate 14 is formed of an insulating material having flexibility. As shown in FIGS. 2 to 5 and 7, an end portion (left end of FIG. 2) is formed on the surface of the nozzle plate 14 on the piezoelectric actuator 3 side. A plurality of wiring portions 34 extending in one direction (rightward in FIG. 2) in the scanning direction. The terminal portions 34a are respectively connected to the contact portions 32a of the plurality of individual electrodes 32. The ends of the plurality of wiring portions 34 opposite to the individual electrodes 32 are connected to the driver IC 38, and the driver IC 38 is disposed on the nozzle plate 14. As described above, since the plurality of individual electrodes 32 and the driver IC 38 are electrically connected via the plurality of wiring portions 34 formed on the nozzle plate 14, a wiring member such as an FPC that has been conventionally required. Can be eliminated, and the number of parts can be reduced to reduce the manufacturing cost of the inkjet head 1. Further, since the nozzle plate 14 is formed of a flexible insulating material, as shown in FIGS. 3 and 4, similarly to a flexible wiring member such as an FPC conventionally used. The nozzle plate 14 can be routed, and the degree of freedom of arrangement of the driver IC 38 and the like is increased.

  As shown in FIG. 2, on the surface of the nozzle plate 14 on which the plurality of wiring portions 34 are formed, a wiring portion for holding the diaphragm 30 as a common electrode at the ground potential via the driver IC 38 is further provided. 40 is formed. Further, as shown in FIGS. 2 and 3, the nozzle plate 14 is also formed with a plurality of wiring portions 41 that connect the control device (not shown) of the inkjet printer 100 and the driver IC 38.

  Here, the nozzle plate 14 is bonded by an adhesive 22 made of an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP). The anisotropic conductive material is, for example, a material in which conductive particles are dispersed in a thermosetting epoxy resin. The anisotropic conductive material has an insulating property when not compressed and has a conductive property when compressed. Have. The adhesive material 22 is compressed and conductive in the connection area between the contact portion 32a of the individual electrode 32 and the terminal portion 34a of the wiring portion 34. The contact material 32a and the terminal portion 34a are Are electrically connected. However, the adhesive material 22 is not compressed in portions other than the electrical connection portion of the contact portion 32a and the terminal portion 34a and has an insulating property. Therefore, it is possible to prevent unnecessary capacitance from being generated in the piezoelectric layer 31 sandwiched between the wiring portion 34 and the diaphragm 30 at portions other than the electrical connection portion of the contact portion 32a and the terminal portion 34a. The driving efficiency of the piezoelectric actuator 3 is improved.

  Further, as shown in FIG. 5, the separation distance (D1 in FIG. 5) between the contact part 32a of the individual electrode 32 and the terminal part 34a of the wiring part 34 formed on the nozzle plate 14 is the other part. Is smaller than the separation distance (D2 in FIG. 5) between the nozzle plate 14 and the piezoelectric layer 31. Therefore, when the nozzle plate 14 is pressed against the piezoelectric layer 31 to bond the nozzle plate 14 and the piezoelectric layer 31, only the adhesive 22 between the contact portion 32a of the individual electrode 32 and the terminal portion 34a of the wiring portion 34 is compressed. Thus, it becomes easy to electrically connect the individual electrode 32 and the wiring portion 34.

  Furthermore, as shown in FIGS. 2 to 5, a plurality of concave portions 14 a each having a rectangular planar shape are formed in a portion of the nozzle plate 14 facing the plurality of individual electrodes 32. Therefore, when the drive voltage is applied to the individual electrode 32 and the piezoelectric layer 31 is deformed, the deformation of the piezoelectric layer 31 is hindered by the nozzle plate 14 or the adhesive 22 that bonds the nozzle plate 14 and the piezoelectric layer 31. In other words, the driving efficiency of the piezoelectric actuator 3 is improved. The recesses 14a are not formed in common over the plurality of individual electrodes 32, but a plurality of recesses 14a are individually formed for the plurality of individual electrodes 32, as shown in FIG. Therefore, the rigidity of the nozzle plate 14 is ensured to some extent by the portion between the recesses 14a. Therefore, for example, when the ink ejection surface (lower surface of the nozzle plate 14) is wiped with a wiper after the purge operation (bubble discharging operation) from the nozzle 20, it is possible to prevent the nozzle plate 14 from being bent. Further, as shown in FIG. 2, a plurality of wiring portions 34 are formed in a region between the plurality of recesses 14 a, that is, a region that does not face the plurality of nozzles 20 and the plurality of pressure chambers 16. Therefore, conductive ink does not adhere to the wiring part 34, and a short circuit between the wiring parts 34 can be prevented. Further, when a driving voltage is applied to the individual electrode 32, the wiring portion 34 does not hinder the deformation of the piezoelectric layer 31.

  Next, a method for manufacturing the above-described inkjet head 1 will be described. First, a process of laminating a plurality of plates other than the nozzle plate 14 (including the diaphragm 30 and the piezoelectric layer 31 of the piezoelectric actuator 3) will be described with reference to FIG. As shown in FIG. 8A, first, a through hole 35 constituting a part of the individual ink flow path 2 is formed in the diaphragm 30 by etching or the like (hole forming step), and the pressure at which the pressure chamber 16 is formed. The chamber plate 13 and the diaphragm 30 are joined by metal diffusion bonding or an adhesive material.

  Next, as shown in FIG. 8B, the through holes 35 of the diaphragm 30 are formed by depositing piezoelectric element particles on the surface of the diaphragm 30 opposite to the pressure chamber plate 13 and performing heat treatment. The piezoelectric layer 31 is formed only in the region where it is not formed (piezoelectric layer forming step). Here, as a method of depositing the piezoelectric element on the vibration plate 30, for example, an aerosol deposition method (AD method) in which ultrafine particle material is deposited by colliding at high speed can be used. In addition, a sputtering method or a CVD (chemical vapor deposition) method can also be used. When the piezoelectric layer 31 is formed by depositing the piezoelectric element particles on the vibration plate 30, the individual ink flow path 2 of the piezoelectric layer 31 is located at a position corresponding to the through hole 35 of the vibration plate 30 in the same manner as the through hole 35. A part of the through hole 36 is formed at the same time.

  Then, as shown in FIG. 8C, the individual electrodes 32 are formed on the surface of the piezoelectric layer 31 opposite to the vibration plate 30 on the area facing the pressure chamber 16 using screen printing, vapor deposition, or the like. In addition, a contact portion 32 a connected to the individual electrode 32 is formed. Further, as shown in FIG. 8D, the ink is piezoelectrically applied to the inner surfaces of the through holes 35 and 36 formed in the diaphragm 30 and the piezoelectric layer 31 by using an AD method, a sputtering method, a CVD method, or the like. A protective film 37 that prevents penetration into the layer 31 is formed (protective film forming step). Then, the base plate 12 and the two manifold plates 10 and 11 are joined to the surface of the pressure chamber plate 13 opposite to the piezoelectric actuator 3. The five metal plates of the two manifold plates 10, 11, the base plate 12, the pressure chamber plate 13, and the vibration plate 30 are first joined at once by diffusion joining or the like, and then the vibration plate 30 The piezoelectric layer 31 may be formed on the surface opposite to the pressure chamber 16.

  Next, the process of forming the nozzle plate 14 will be described with reference to FIG. As shown in FIG. 9A, when the nozzle plate 14 is bonded to the piezoelectric layer 31, a plurality of recesses 14a are formed in regions that respectively face the plurality of individual electrodes 32, and excimer laser processing or the like is performed. Thus, a plurality of nozzles 20 are formed. Next, as shown in FIG. 9B, a wiring portion 34 (and a terminal portion 34a) extending rightward is formed in a portion on the right side of the recess 14a. Then, as shown in FIG. 9C, an adhesive 22 made of an anisotropic conductive material is attached to the upper surface of the nozzle plate 14 to be bonded to the piezoelectric layer 31 by screen printing or the like (attachment process). ). In this attaching step, the adhesive material 22 may be patterned and attached only to the portion of the nozzle plate 14 to be bonded to the piezoelectric layer 31, but the adhesive material 22 may be attached to the entire surface of the nozzle plate 14. . Even in this case, since the concave portion 14a is formed in the portion of the nozzle plate 14 facing the individual electrode 32, the deformation of the piezoelectric layer 31 when the drive voltage is applied to the individual electrode 32 causes the nozzle plate 14 or this nozzle to be deformed. It is not hindered by the adhesive 22 attached to the plate 14.

  Then, as shown in FIG. 10, the nozzle plate 14 is bonded to the piezoelectric layer 31 of the piezoelectric actuator 3 with the adhesive 22 (bonding process). At this time, the contact portion 32a of the individual electrode 32 is brought into contact with the adhesive material 22 attached to the surface of the terminal portion 34a of the wiring portion 34, and the adhesive material 22 of this portion is compressed to compress the individual electrode 32 and the wiring portion 34. Are connected in a conductive state, and the other portion of the wiring portion 34 is bonded to the piezoelectric layer 31 in an insulating state by the uncompressed adhesive 22. At the same time, the nozzle plate 14 and the piezoelectric layer 31 are bonded to each other by the adhesive 22 attached to a portion other than the wiring portion 34 of the nozzle plate 14. Since the individual electrode 32 and the wiring part 34 have a thickness of about 5 μm, the separation distance between the contact part 32a of the individual electrode 32 and the terminal part 34a of the wiring part 34 formed on the nozzle plate 14 (FIG. 5). D1) is smaller than the separation distance (D2 in FIG. 5) between the nozzle plate 14 and the piezoelectric layer 31 in the other portions. Therefore, when the nozzle plate 14 and the piezoelectric layer 31 of the piezoelectric actuator 3 are bonded, the contact portion 32a of the individual electrode 32 and the terminal portion of the wiring portion 34 are simply pressed against the piezoelectric layer 31. Only the adhesive 22 between 34a can be compressed, and it becomes easy to electrically connect the individual electrode 32 and the wiring part 34.

  Note that the thickness of the peripheral portion of the nozzle 20 (left end portion of the nozzle plate 14 in FIG. 9) is made slightly thinner than the thickness of the portion where the wiring portion 34 is formed (right end portion of the nozzle plate 14 in FIG. 9). Thus, the separation distance (D1 in FIG. 5) between the contact portion 32a of the individual electrode 32 and the terminal portion 34a of the wiring portion 34 formed on the nozzle plate 14 is set to be different from that of the nozzle plate 14 and the piezoelectric portion in the other portions. You may make it smaller than the separation distance (D2 of FIG. 5) between the layers 31. FIG.

  According to the inkjet head 1 and the manufacturing method thereof described above, the following effects can be obtained. A plurality of wiring portions 34 for connecting a plurality of individual electrodes 32 of the piezoelectric actuator 3 and a driver IC 38 for supplying a driving voltage to the plurality of individual electrodes 32 are formed on the nozzle plate 14 made of an insulating material. 14 can be provided with the function of a wiring member such as an FPC, and the wiring member can be omitted. Therefore, the number of components can be reduced and the manufacturing cost of the inkjet head 1 can be reduced. A driver IC 38 can be disposed on the nozzle plate 14. Furthermore, since the nozzle plate 14 is flexible, it can be routed in the same manner as an FPC or the like, and the degree of freedom of arrangement of the driver IC 38 is increased. Furthermore, it is possible to electrically connect the plurality of individual electrodes 32 and the plurality of wiring portions 34 at the same time that the nozzle plate 14 is bonded to the piezoelectric actuator 3, thereby simplifying the manufacturing process of the inkjet head 1.

  Further, in the bonding process between the piezoelectric layer 31 and the nozzle plate 14 of the piezoelectric actuator 3, the piezoelectric layer 31 and the nozzle plate 14 are bonded by the adhesive 22 made of an anisotropic conductive material. Electrical connection can be made at one time by using one type of adhesive 22, and the manufacturing process can be simplified to reduce the manufacturing cost. Further, the adhesive material 22 between the individual electrode 32 and the wiring portion 34 is compressed and conductive, but the other portion of the adhesive material 22 is not compressed and has insulation. It is possible to suppress generation of unnecessary capacitance in the piezoelectric layer 31 sandwiched between the wiring portion 34 and the vibration plate 30 at a portion other than the electrical connection portion with the piezoelectric actuator 3. Efficiency is improved.

  Next, modified embodiments in which various modifications are made to the embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals, and description thereof is omitted as appropriate.

[First modification]
In the embodiment, the recess is formed in the portion of the nozzle plate facing the individual electrode 32, but the recess may be formed on the piezoelectric layer side. For example, as shown in FIG. 11, a plurality of recesses 30a are formed in portions facing the plurality of individual electrodes 32 of the diaphragm 30A, and a recess 31a corresponding to the recess 30a of the diaphragm 30A is formed in the piezoelectric layer 31A. May be. In this case, the recess 31a of the piezoelectric layer 31A can be simultaneously formed by forming the piezoelectric layer 31A with a uniform thickness on the surface of the vibration plate 30A on which the recess 30a is formed by an AD method, a CVD method, or the like. it can. In this case, after the adhesive 22 is attached to the piezoelectric layer 31A side, the nozzle plate 14A is bonded to the piezoelectric layer 31A.

[Second modification]
In the attaching step of attaching the adhesive material 22 to the nozzle plate 14 (or the piezoelectric layer 31), when the adhesive material 22 is patterned and attached, there is a gap between the nozzle plate 14 and the piezoelectric layer 31 by the adhesive material 22. Since the gap is formed and the deformation of the piezoelectric layer 31 is not easily inhibited by the nozzle plate 14 or the adhesive 22 attached to the nozzle plate 14, as shown in FIG. 12, the nozzle plate 14B (or the piezoelectric layer 31) The recess may be omitted. In addition, in order to deposit the adhesive 22 by patterning, in addition to the above-described screen printing, the adhesive 22 is adhered to the entire surface of the nozzle plate 14 (14B), and then the adhesive that is not bonded to the piezoelectric layer 31 is used. It is also possible to remove part 22 with a laser or the like.

[Third modification]
The electrical connection between the contact part 32a of the individual electrode 32 formed on the piezoelectric layer 31 and the terminal part 34a of the wiring part 34 formed on the nozzle plate 14, and the piezoelectric layer 31 and the nozzle plate at a portion other than the electrical connection part The 14 bonds can also be performed by separate adhesive materials. For example, a conductive paste may be used for electrical connection between the individual electrode 32 and the wiring portion 34, and a non-conductive adhesive may be used for bonding the piezoelectric layer 31 and the nozzle plate 14 in other portions. However, in this case, the conductive paste and the non-conductive adhesive are used so that the electrical connection between the individual electrode 32 and the wiring portion 34 and the adhesion between the piezoelectric layer 31 and the nozzle plate 14 can be performed simultaneously. Are preferably close to each other in curing temperature.

[Fourth modification]
The nozzle plate is formed of a metal material such as stainless steel, and this thin film is formed by forming a thin film of an insulating material such as alumina on one surface of this metal plate by the AD method, sputtering method, or CVD method. The nozzle plate may be insulated on the formed surface. In this case, the surface of the nozzle plate on which the thin film is formed may be a surface that faces the piezoelectric actuator 3 and on which the plurality of wiring portions 34 are formed.

[Fifth modification]
In the embodiment, the manifold is formed above the base plate and the pressure chamber is formed below, but the position of the manifold is not limited to the upper side of the pressure chamber. A part of the manifold may be formed at the same height as the pressure chamber. For example, the lower surface of the pressure chamber and the lower surface of the manifold may be the same height. An inkjet head 200 shown in FIG. 13 includes a manifold plate 112 in which a manifold 117 is formed, a pressure chamber plate 113 in which a pressure chamber 116 is formed, a piezoelectric actuator 3 having a vibration plate 30 and a piezoelectric layer 31, and anisotropy. A conductive layer 22 and a nozzle plate 14 are provided. A manifold plate 112 is joined to the diaphragm 30 side of the piezoelectric actuator 3 via a pressure chamber plate 113, and a nozzle plate 14 is joined to the piezoelectric layer 31 side of the piezoelectric actuator 3 via an anisotropic conductive layer 22. . Here, the diaphragm 30 defines the lower surface of the pressure chamber 116 and also defines the lower surface of the manifold 117. That is, the lower surface of the pressure chamber 116 and the lower surface of the manifold 117 are formed at the same height. Thus, when a part of the manifold is formed at the same height as the pressure chamber, the thickness of the inkjet head can be reduced.

  The above embodiment is an example in which the present invention is applied to an ink jet head that ejects ink. However, the present invention can also be applied to other liquid ejecting apparatuses that eject liquid other than ink. For example, a conductive paste is sprayed to form a wiring pattern on the substrate, an organic light emitter is sprayed to the substrate to form an organic electroluminescence display, and an optical resin is sprayed to the substrate. Thus, the present invention can also be applied to various liquid ejecting apparatuses used for forming optical devices such as optical waveguides.

1 is a schematic perspective view of an ink jet printer according to an embodiment of the present invention. It is a top view of an inkjet head. It is the III-III sectional view taken on the line of FIG. FIG. 4 is a cross-sectional view corresponding to FIG. 3 of an inkjet head arranged at an angle. It is the elements on larger scale of FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is a principal part enlarged view of FIG. It is a figure which shows the process of laminating | stacking several plates other than the nozzle plate 14, (a) is a joining process of a pressure chamber plate and a diaphragm, (b) is a piezoelectric layer formation process, (c) is an individual electrode formation process. , (D) shows a protective film forming process, and (e) shows a joining process with a manifold plate and a base plate. It is a figure which shows the formation process of a nozzle plate, (a) shows the process of forming a nozzle and a recessed part, (b) shows the process of forming a wiring part, (c) shows the adhesion process of an adhesive material, respectively. It is a figure which shows the state which adhered the nozzle plate to several laminated | stacked plates other than a nozzle plate. It is sectional drawing equivalent to FIG. 5 of a 1st modification. It is sectional drawing equivalent to FIG. 5 of a 2nd modification. FIG. 6 is a cross-sectional view corresponding to FIG. 5 of an ink jet head in which a manifold is arranged next to a pressure chamber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head 2 Individual ink flow path 3 Piezoelectric actuator 13 Pressure chamber plate 14B Nozzle plates 14, 14A, 14B Nozzle plate 14a Recess 16 Pressure chamber 17 Manifold 20 Nozzle 22 Adhesive material 30, 31A Vibration plate 30a Recess 31, 31A Piezoelectric layer 32 Individual electrode 32a Contact portion 34 Wiring portion 34a Terminal portion 35 Through hole 36 Through hole 37 Protective film

Claims (21)

A liquid ejecting apparatus,
A plurality of liquid flow paths each including a plurality of nozzles for ejecting liquid and a plurality of pressure chambers respectively communicating with the plurality of nozzles;
An actuator for selectively changing the volume of the plurality of pressure chambers;
The liquid channel is formed by a plurality of stacked plates,
Between the pressure chamber plate forming the plurality of pressure chambers included in the plurality of plates, and the nozzle plate having at least an insulating property on the surface facing the pressure chamber plate, the nozzle is formed. An actuator is provided,
The actuator includes: a diaphragm covering the plurality of pressure chambers; a piezoelectric layer provided on a surface of the diaphragm opposite to the plurality of pressure chambers; and a surface of the piezoelectric layer opposite to the diaphragm. A plurality of individual electrodes formed at positions facing each of the plurality of pressure chambers;
A liquid ejecting apparatus, wherein a plurality of wiring portions respectively connected to the plurality of individual electrodes are formed on a surface of the nozzle plate on the actuator side.   The liquid ejecting apparatus according to claim 1, wherein the liquid flow path is formed so as to penetrate the actuator.   A through hole that constitutes a part of the liquid channel is formed in the piezoelectric layer, and a protective film that prevents the liquid from penetrating the piezoelectric layer is formed on the inner surface of the through hole. The liquid ejecting apparatus according to claim 2.   The liquid ejecting apparatus according to claim 1, wherein the nozzle plate is made of a flexible insulating material.   The liquid ejecting apparatus according to claim 1, wherein a plurality of recesses are formed in portions of the nozzle plate facing the plurality of individual electrodes.   5. The liquid ejecting apparatus according to claim 1, wherein a plurality of recesses are formed in portions of the vibration plate facing the plurality of individual electrodes.   The liquid ejecting apparatus according to claim 1, wherein the nozzle plate and the piezoelectric layer are bonded with an anisotropic conductive material having conductivity in a compressed state.   In the connection area between the contact part of the individual electrode and the terminal part of the wiring part, the anisotropic conductive material is compressed and conductive, and in the area other than the connection area, the anisotropic conductive material is conductive. The liquid ejecting apparatus according to claim 7, wherein the liquid ejecting apparatus has no property.   9. The separation distance between the contact portion of the individual electrode and the terminal portion of the wiring portion is smaller than the separation distance between the nozzle plate and the piezoelectric layer in other portions. The liquid ejecting apparatus according to 1.   The plurality of wiring portions are formed in a region not facing the plurality of nozzles and the plurality of pressure chambers on a surface of the nozzle plate on the actuator side. The liquid ejecting apparatus according to 1. And a common liquid chamber communicating with the plurality of pressure chambers,
The liquid ejecting apparatus according to claim 1, wherein the common liquid chamber is disposed on a side opposite to the nozzle with respect to the actuator.   The liquid ejecting apparatus according to claim 11, wherein the nozzle is directed downward, and the common liquid chamber is disposed above the nozzle.   The liquid ejecting apparatus according to claim 11, wherein the plurality of pressure chambers are formed between the actuator and the common liquid chamber.   An individual liquid flow path that communicates with the nozzle from the common liquid chamber through the plurality of pressure chambers is formed, and is disposed so as to extend upward toward the common liquid chamber side of the individual liquid flow path. The liquid ejecting apparatus according to claim 12, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.   The liquid ejecting apparatus according to claim 4, wherein the insulating material having flexibility is polyimide.   The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is an inkjet head.   An ink jet printer comprising the liquid ejecting apparatus according to claim 16. A method for manufacturing the liquid ejecting apparatus according to claim 1, comprising:
A wiring part forming step of forming the wiring part on a surface of the nozzle plate bonded to the piezoelectric layer;
A bonding step of bonding the nozzle plate to the actuator,
In the bonding step, the terminal portion of the wiring portion is bonded to the contact portion of the individual electrode in a conductive state, and the nozzle plate portion other than the terminal portion is bonded to the piezoelectric layer in an insulating state. Manufacturing method of liquid ejecting apparatus. Prior to the bonding step, an adhesion step of attaching an anisotropic conductive material to the nozzle plate or the bonding surface of the piezoelectric layer,
In the bonding step, the contact portion of the individual electrode and the other of the terminal portion of the wiring portion are brought into contact with the anisotropic conductive material attached to one surface of the contact portion of the individual electrode and the terminal portion of the wiring portion. The nozzle plate is adhered to the piezoelectric layer by the anisotropic conductive material of the other part while compressing the anisotropic conductive layer of this part and connecting the individual electrode and the wiring part in a conductive state. The method of manufacturing a liquid ejecting apparatus according to claim 18.   Prior to the adhering step, a hole forming step for forming a hole constituting a part of the liquid flow path in the diaphragm, and particles of piezoelectric material are deposited on the surface of the diaphragm opposite to the pressure chamber. The method of manufacturing a liquid ejecting apparatus according to claim 18, further comprising: a piezoelectric layer forming step of forming the piezoelectric layer only in a region where the hole of the diaphragm is not formed.   In the piezoelectric layer forming step, liquid is prevented from penetrating into the piezoelectric layer on the inner surface of a through hole that is formed at a position corresponding to the hole of the diaphragm of the piezoelectric layer and forms a part of the liquid flow path. The method for manufacturing a liquid ejecting apparatus according to claim 20, further comprising a protective film forming step of forming a protective film.

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