Liquid ejection head and liquid ejection apparatus

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus which are highly mountable. According to one embodiment, a liquid ejection head includes a substrate, a piezoelectric member, a vibration plate, and an electrode wiring. The substrate has a wiring surface. The piezoelectric member is provided on the wiring surface of the substrate. The piezoelectric member has an inclined surface in which one side surface portion is inclined at an angle of more than 90 DEG and less than 180 DEG with respect to the wiring surface. The vibrating plate is disposed so as to face the piezoelectric member on the opposite side from the substrate. An electrode wiring is formed on the inclined surface of the piezoelectric member.

Description

Technical Field

[0001] Embodiments of the present invention relate to a liquid ejection head and a liquid ejection device. Background Art

[0002] As a driving source for a liquid ejection device such as an inkjet printer head, a piezoelectric actuator using a piezoelectric body such as PZT is used. The inkjet printer head and the like have the following structure: actuators are arranged side by side at very fine intervals, multiple grooves are formed in one piezoelectric body, and multiple column parts divided by the grooves are each set as one actuator. In order to drive the actuator, an electrode is provided on the surface of the column part that is orthogonal to the telescopic surface, and the electrode on the surface of the actuator is directly connected to a flexible cable by welding.

[0003] In such a configuration, since the joint strength between the actuator and the flexible cable is low, the joint portion is easily damaged, and the electrical connection is easily disconnected. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a liquid ejection head and a liquid ejection device with high mountability.

[0005] A liquid ejection head according to one embodiment includes a substrate, a piezoelectric component, a vibration plate, and electrode wiring. The substrate has a wiring surface. The piezoelectric component is arranged on the wiring surface of the substrate. The piezoelectric component has an inclined surface whose side surface is inclined at an angle greater than 90° and less than 180° relative to the wiring surface. The vibration plate is arranged opposite to the side of the piezoelectric component opposite to the substrate. The electrode wiring is formed on the inclined surface of the piezoelectric component. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a cross-sectional view showing the structure of the ink jet head according to the embodiment.

[0007] Figure 2 It is a cross-sectional view showing the structure of the inkjet head.

[0008] Figure 3 It is a perspective view showing the structure of the inkjet head.

[0009] Figure 4 It is an explanatory diagram showing a method for manufacturing the ink jet head.

[0010] Figure 5 It is an explanatory diagram showing an inkjet head according to another embodiment.

[0011] Figure 6 It is an explanatory diagram showing a schematic configuration of an inkjet recording apparatus according to an embodiment.

[0012] Description of Reference Numerals

[0013] 1… inkjet head, 10… substrate, 20… actuator, 202… piezoelectric member, 21… driven piezoelectric element, 22… non-driven piezoelectric element, 23… groove, 30… vibration plate, 31… pressure chamber, 32… common chamber, 33… communication portion, 40… flow path portion, 42… partition wall portion, 50… nozzle plate, 51… nozzle, 60… frame portion, 70… driving circuit, 71… FPC, 72… driving IC, 73… printed wiring board, 731… head control circuit, 100… inkjet recording device, 111… housing, 112… medium supply portion, 113… image forming part, 114…medium discharge part, 115…conveying device, 117…support part, 118…conveying belt, 119…support plate, 120…belt roller, 121…guide plate pair, 122…conveying roller, 130…head unit, 132…ink tank, 133…connecting flow path, 134…supply pump, 116…control part, 1161…control circuit, 211…piezoelectric layer, 221…internal electrode, 222…internal electrode, 223…external electrode, 224…external electrode, 301…vibration region, 302…support region, 405, 406…flow path substrate. DETAILED DESCRIPTION

[0014] Below, refer to Figures 1 to 6 The actuator 20 according to the embodiment, the inkjet head 1 as a liquid ejecting head, and the inkjet recording apparatus 100 as a liquid ejecting device will be described. Figure 1 and Figure 2 It is a cross-sectional view showing a schematic structure of the inkjet head 1 . Figure 2 Show Figure 1 Section II-II. Figure 3 is a perspective view showing a part of the inkjet head 1, Figure 4 is an explanatory diagram showing a method for manufacturing an inkjet head, Figure 6 1 is an explanatory diagram showing a schematic configuration of the inkjet recording apparatus 100. Arrows X, Y, and Z in the figure respectively indicate three directions orthogonal to each other. In each figure, the configuration is appropriately enlarged, reduced, or omitted for the purpose of explanation.

[0015] like Figure 1 and Figure 2 As shown, the inkjet head 1 includes a substrate 10 , a pair of actuators 20 , a flow path portion 40 , a nozzle plate 50 having a plurality of nozzles 51 , a frame portion 60 , and a drive circuit 70 .

[0016] As an example, the inkjet head 1 includes two actuators 20, each of which has two nozzle rows in which a plurality of nozzles 51 are arranged in a row direction (X direction), a pressure chamber row in which a plurality of pressure chambers 31 are arranged in a row direction, and an element row in which a plurality of piezoelectric elements 21 and 22 are arranged in a row direction. In this embodiment, an example is shown in which the stacking direction of the plurality of piezoelectric layers 211 in the actuator 20, the vibration direction of the driving piezoelectric element 21, and the vibration direction of the vibration plate 30 are all along the Z direction.

[0017] The substrate 10 is a circuit substrate supporting a pair of actuators 20. The substrate 10 is formed in a plate shape by, for example, alumina, etc., and has a mounting surface 101 as a surface along the extension direction and the parallel direction. Substrate electrode layers 11 and 12 are formed on the mounting surface 101 of the substrate 10 on which the actuators 20 are mounted. The mounting surface 101 is also referred to as a wiring surface. For example, in the mounting surface 101 of the substrate 10, a substrate electrode layer 11 constituting an independent electrode is formed in the outer area of ​​the two side portions of the pair of actuators 20 in the direction in which the pair of actuators 20 are opposed to each other, and a substrate electrode layer 12 constituting a common electrode is formed in the inner area between the pair of actuators 20. The opposing surfaces of the pair of actuators 20 are the inner area, and the surfaces of the pair of actuators 20 on the opposite side to the opposing surfaces are the outer area.

[0018] For example, in the mounting surface 101 of the substrate 10, the substrate electrode layer 11 is separated in the column direction in the outer region of the pair of actuators 20, thereby forming a predetermined wiring pattern having independent wirings 102 as a plurality of substrate wirings. For example, the independent wirings 102 are continuous with the external electrodes 223 (electrodes) formed on one side surface portion of the surface of the actuator 20, which becomes the outer side, and constitute independent electrodes.

[0019] As an example, in a region near the actuator 20 on the mounting surface 101 , at least within a reflected light range reached by reflected light from the inclined surface, the independent wiring 102 and the external electrode 223 on the side surface of the actuator 20 extend in the same direction.

[0020] In the outer area of ​​the mounting surface 101 of the substrate 10 , a mounting portion 76 is provided for mounting the FPC 71 as a component via the ACF 75 .

[0021] The independent wiring 102 is formed of a conductive material by a method such as vacuum deposition or electroless plating, and is patterned into a predetermined shape by a patterning process based on photolithography, for example.

[0022] In the mounting surface 101 of the substrate 10, the substrate electrode layer 12 formed in the inner region between the pair of actuators 20 constitutes a common wiring 103 (wiring). The common wiring 103 is continuous with the external electrode 224 (electrode) formed on the other inner side of the actuator 20 to constitute a common electrode.

[0023] The actuator 20 is bonded to the mounting surface 101 which is one side of the substrate 10. For example, two actuators 20 are arranged side by side in the Y direction.

[0024] like Figures 1 to 3 As shown, the actuator 20 includes a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 that form the actuator and are alternately arranged in a row direction, and a connecting portion 26 that integrally connects the plurality of piezoelectric elements 21 and 22 on the substrate 10 side.

[0025] The actuator 20 is a stacked piezoelectric component in which a plurality of piezoelectric layers 211 and a plurality of internal electrodes 221 and 222 are stacked.

[0026] In the actuator 20 , a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 are arranged side by side in one direction at fixed intervals.

[0027] The actuator 20 is divided into a plurality of grooves 23 formed from the top side of the vibration plate 30 to a predetermined depth, and a plurality of driving piezoelectric elements 21 and non-driving piezoelectric elements 22 are arranged in a row direction at the same pitch, for example. The grooves 23 are formed to cover the entire length of the actuator 20 in the extension direction.

[0028] The side surface portion 203 of the pair of actuators 20 on the outer side of the Y direction, which is the opposing direction of the pair of actuators 20, is configured as a trapezoidal shape that is inclined and expanded toward the substrate 10 side. The width of the actuator 20, for example, in the short side direction, gradually increases from the top side to the substrate 10 side. The cross-sectional shape of the cross section of the actuator 20 along the short side direction is formed into a trapezoidal shape. That is, the actuator 20 has an inclined surface inclined toward the side surface portion 203 on one side in the short side direction. For example, one side surface portion 203 of the piezoelectric member 202 of the actuator 20 has an inclined surface with an angle greater than 90° and less than 180° with the mounting surface 101 of the substrate 10.

[0029] In addition, in each piezoelectric member 202, the angle between the other side surface portion 204 on the inner side of the pair of actuators 20 and the mounting surface 101 of the substrate 10 is configured to be smaller than the angle between the one side surface portion 203 and the mounting surface 101. As an example, the side surface portion 204 extends along the Z direction and has an angle of 90° with the mounting surface 101 of the substrate 10.

[0030] In the actuator 20, for example, a plurality of driving piezoelectric elements 21 and a plurality of non-driving piezoelectric elements 22 are respectively configured into a rectangular shape whose short side direction is along the column direction of the element column in a plan view viewed from the Z direction and whose long side direction is along an extension direction orthogonal to the column direction and the Z direction.

[0031] The plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 are configured to have a trapezoidal shape in which one side of the independent electrode forms an inclined surface expanding toward the substrate side, and the other side of the common electrode extends along the Z direction and is inclined on one side when viewed from a cross section.

[0032] The driving piezoelectric elements 21 are arranged in the Z direction at positions respectively facing the plurality of pressure chambers 31 formed in the flow path portion 40. As an example, the center position of the driving piezoelectric elements 21 in the row direction and the extension direction and the center position of the pressure chambers 31 in the row direction and the extension direction are arranged side by side in the Z direction.

[0033] The non-driven piezoelectric elements 22 are arranged in the Z direction at positions facing the plurality of partition walls 42 formed in the flow path 40. The plurality of driven piezoelectric elements 21 and the plurality of non-driven piezoelectric elements 22 are alternately arranged in parallel with the grooves 23 interposed therebetween in the row direction.

[0034] For example, the piezoelectric member 202 constituting the actuator 20 is a stacked piezoelectric member composed of a stacked piezoelectric body, and is formed by stacking and sintering sheet-shaped piezoelectric materials.

[0035] The piezoelectric member 202 includes: a plurality of stacked piezoelectric layers 211; internal electrodes 221 and 222 formed on the main surface of each piezoelectric layer 211; an external electrode 223 formed on the side surface 203 on one side; and an electrode 224 formed on the side surface 204 on the other side. The side surface opposite to the facing surface of the pair of actuators 20, that is, the outer region side, is the side surface 203 on one side of the piezoelectric member 202. The facing surface of the pair of actuators 20, that is, the inner region side, is the side surface 204 on the other side of the piezoelectric member 202. It should be noted that, as an example, the driving piezoelectric element 21 and the non-driving piezoelectric element 22 have the same stacked structure.

[0036] The piezoelectric layer 211 is formed into a thin plate by a piezoelectric ceramic material such as a PZT (lead zirconate titanate) system or a lead-free KNN (sodium potassium niobate) system. The plurality of piezoelectric layers 211 are stacked in a manner such that the thickness direction is along the stacking direction and are bonded to each other. For example, in the present embodiment, the thickness direction and the stacking direction of the piezoelectric layer 211 are arranged along the vibration direction (Z direction).

[0037] The internal electrodes 221 and 222 are conductive films formed of a sinterable conductive material such as silver palladium in a predetermined shape. The internal electrodes 221 and 222 are formed in a predetermined area of ​​the main surface of each piezoelectric layer 211. The internal electrodes 221 and 222 have different poles. For example, one internal electrode 221 is formed in an area that reaches one end of the piezoelectric layer 211 and does not reach the other end of the piezoelectric layer 211 in a direction that is orthogonal to both the side-by-side direction of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22, that is, the column direction (X direction) and the vibration direction (Z direction), that is, the extension direction (Y direction). Another internal electrode 222 is formed in an area that does not reach one end of the piezoelectric layer 211 and reaches the other end of the piezoelectric layer 211 in the extension direction. The internal electrodes 221 and 222 are connected to the external electrodes 223 and 224 formed on the side surfaces of the piezoelectric elements 21 and 22, respectively.

[0038] In addition, the piezoelectric member 202 constituting the driving piezoelectric element 21 and the non-driving piezoelectric element 22 may also include a dummy layer that is not deformed and to which an electric field is not applied, at either or both of the ends on the substrate 10 side and the nozzle plate 50 side. The dummy layer is made of the same material as the piezoelectric body layer 211, does not function as a piezoelectric body, and becomes a base when fixed, or becomes a grinding amount for grinding to improve the accuracy during or after assembly.

[0039] The external electrodes 223 and 224 are formed on the surfaces of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22 , and are connected to the ends of the internal electrodes 221 and 222 .

[0040] For example, the external electrode 223 is formed on an inclined surface of one side surface 203 in the extending direction of the piezoelectric member 202. The external electrode 223 is separated for each element to form an independent wiring. Each external electrode 223 is continuous with the independent wiring 102 formed by the substrate electrode layer 11 on the substrate 10.

[0041] For example, each external electrode 223 extends in the same direction as each independent wiring 102 in a region near the actuator 20 at least when viewed from the irradiation direction of light in a photolithography process.

[0042] In the present embodiment, the independent wiring 102 of the wiring portion of the substrate extends in the same direction as the external electrode 223 of the wiring of the inclined surface of the actuator 20, which is formed along the mounting surface 101 and reaches at least the reflected light range. Specifically, for example, in a top view viewed from the third direction (Z direction) which is the exposure direction, the independent wiring 102 extends on the same straight line toward the second direction (Y direction) which is the short side direction of the piezoelectric member 202. That is, the independent wiring 102 extends on a straight line orthogonal to the first direction (X direction) which is the arrangement direction of the plurality of nozzles 51, and in a direction perpendicular to the upper and lower sides of the edge of the side surface portion 203 which is the inclined surface, at least within the reflected light range where the distance from the piezoelectric member 202 is less than a predetermined distance. In addition, the independent wiring 102 of the substrate 10 extends in the second direction (Y direction) which is the short side direction of the actuator 20 along the mounting surface 101.

[0043] The external electrode 224 is formed on the other side surface portion 204 in the extending direction of the piezoelectric member 202. In addition, the external electrode 224 is continuous with the common wiring 103 formed of the substrate electrode layer 12 on the substrate 10.

[0044] The external electrodes 223 and 224 are formed of Ni, Cr, Au, etc. by plating or sputtering. The external electrode 223 and the external electrode 224 have different polarities.

[0045] In this embodiment, as an example, the external electrode 223 is an independent electrode separated for each piezoelectric element 21, and the external electrode 224 is a common electrode. The electrode layer formed on one side of the piezoelectric member 202 during the manufacturing process is divided for the external electrode 223 that becomes an independent electrode of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22, and is independently arranged for each piezoelectric element 21. That is, the electrode layers are separated and independent from each other in the parallel direction, and constitute the external electrodes 223 as a plurality of independent electrodes.

[0046] The external electrodes 223 are separated from each other by the grooves 23, and are connected to the drive circuit 70 via the independent wiring 102 on the substrate 10, for example, and via the FPC 71 which is an example of a wiring substrate, that is, a flexible substrate. For example, each external electrode 223 is connected to the control unit 116 as a drive unit via the drive IC 72 of the drive circuit 70 using the FPC 71 connected by the ACF mounting using the ACF 75, and is configured to be driven and controlled by the control based on the control circuit 1161. It should be noted that the external electrode 224 can also be wound on the side of the external electrode 223 side and connected to the drive circuit 70 via the FPC 71.

[0047] The external electrodes 224 are connected to each other on the other side of the piezoelectric member 202 and to the common wiring 103 on the substrate 10, and are grounded, for example.

[0048] In addition, the vibration direction of each piezoelectric element 21, 22 is along the stacking direction, and is displaced in the d33 direction by application of an electric field.

[0049] As an example, each of the piezoelectric elements 21 and 22 has 3 or more layers and 50 or less layers, the thickness of each layer is set to be 10 μm or more and 40 μm or less, and the product of the thickness and the total number of stacked layers is set to be less than 1000 μm.

[0050] The driving piezoelectric element 21 vibrates by applying a voltage to the internal electrodes 221 and 222 via the external electrodes 223 and 224. In the present embodiment, the driving piezoelectric element 21 vibrates longitudinally along the stacking direction of the piezoelectric layer 211. The longitudinal vibration referred to here refers to, for example, "vibration in the thickness direction defined by the piezoelectric constant d33". The driving piezoelectric element 21 displaces the vibration plate 30 and deforms the pressure chamber 31 through the longitudinal vibration.

[0051] The flow path portion 40 includes: a vibration plate 30 disposed to face one side of the actuator 20 in the deformation direction; and a plurality of flow path substrates 405 and 406 stacked on one side of the vibration plate 30 .

[0052] The vibration plate 30 is provided between the flow path substrate 405 and the actuator 20 in the vibration direction. The vibration plate 30 and the flow path substrate 405 constitute the flow path portion 40. The vibration plate 30 extends in a direction intersecting the side surface of the piezoelectric member 202 where the individual electrodes and the common electrode are formed.

[0053] The vibration plate 30 extends along a surface perpendicular to the Z direction as the vibration direction, and is bonded to one side of the vibration direction of the plurality of piezoelectric elements 21 and 22, that is, to the surface on the nozzle plate 50 side. The vibration plate 30 is configured to be deformable, for example. The vibration plate 30 is bonded to the driving piezoelectric element 21 and the non-driving piezoelectric element 22 of the actuator 20, and the frame portion 60. For example, the vibration plate 30 has a vibration region 301 facing the piezoelectric elements 21 and 22, and a support region 302 facing the frame portion 60.

[0054] The vibration region 301 is, for example, a flat plate configured so that the thickness direction becomes the vibration direction of the piezoelectric layer 211. The surface direction of the vibration plate 30 extends in the parallel direction of the plurality of driving piezoelectric elements 21 and the plurality of non-driving piezoelectric elements 22. The vibration plate 30 is, for example, a metal plate. The vibration plate 30 has a plurality of vibration parts that are opposite to each pressure chamber 31 and can be displaced independently. The vibration plate 30 is formed by connecting a plurality of vibration parts in an integral manner.

[0055] As an example, the vibration plate 30 is made of nickel or SUS plate, and the thickness dimension along the vibration direction is about 5μm to 15μm. It should be noted that in the vibration area 301, folds and steps can also be formed in the parts adjacent to the vibration parts or between the vibration parts adjacent to each other, so that multiple vibration parts are easily displaced. The vibration area 301 is deformed by displacing the part opposite to the driving piezoelectric element 21 through the extension and compression of the driving piezoelectric element 21. For example, the vibration plate 30 is formed by electroplating or the like. The vibration plate 30 is joined to the upper end surface of the actuator 20 by bonding or the like.

[0056] The support region 302 is a plate-shaped member disposed between the frame portion 60 and the flow channel substrate 405. The support region 302 has a communication portion 33 having a through hole communicating with the common chamber 32.

[0057] For example, the communication portion 33 includes a filter member having a plurality of fine holes through which liquid can pass as through holes.

[0058] The flow path substrates 405 and 406 are arranged between the nozzle plate 50 and the vibration plate 30 in the vibration direction. For example, the flow path substrate 405 is bonded to one side of the vibration direction of the vibration plate 30. The flow path substrate 406 is bonded to one side of the flow path substrate 405 in the vibration direction.

[0059] The flow path substrates 405 and 406 form a predetermined ink flow path including a plurality of pressure chambers 31 and a plurality of independent flow paths that communicate the pressure chambers 31 with the common chamber 32 .

[0060] For example, the flow channel substrate 405 includes a partition wall portion 41 , a partition wall portion 42 , and a peripheral wall portion 43 .

[0061] For example, the partition wall portion 41 is a wall member that partitions the rows of pressure chambers 31 that face the pair of actuators 20 .

[0062] The partition wall portion 42 is a wall member that separates the plurality of pressure chambers 31 arranged in parallel in the parallel direction and constitutes both side portions of the pressure chambers 31. The partition wall portion 42 is disposed opposite to the non-driven piezoelectric element 22 via the vibration plate 30 and is supported by the non-driven piezoelectric element 22. A plurality of partition wall portions 42 are provided at the same pitch as the pitch at which the plurality of pressure chambers 31 are arranged in parallel.

[0063] The peripheral wall portion 43 is a wall member that surrounds the outer periphery of the ink flow path including a plurality of independent flow paths or a common flow path.

[0064] The flow path substrate 406 includes a frame portion 44 that forms a flow path that communicates between each pressure chamber 31 and the nozzle 51 .

[0065] In the flow path section 40, two rows of pressure chambers 31 arranged side by side in the X direction are formed in each actuator 20. In each row, the pressure chambers 31 arranged side by side in the X direction are separated by a partition wall section 42. That is, both sides of the parallel direction of the pressure chambers 31 are formed by the partition wall section 42. In addition, the row of pressure chambers 31 arranged opposite to one actuator 20 and the row of pressure chambers 31 arranged opposite to the other actuator 20 are separated by the partition wall section 41. Each pressure chamber 31 is connected to a nozzle 51 formed on a nozzle plate 50 arranged on one side. In addition, the side of the pressure chamber 31 opposite to the nozzle plate 50 is blocked by the vibration plate 30.

[0066] The plurality of pressure chambers 31 are spaces formed on one side of the vibration region 301 of the vibration plate 30, and are connected to the common chamber 32 via an independent flow path or a communication portion 33. The plurality of pressure chambers 31 are connected to the nozzles 51 formed on the nozzle plate 50. In addition, the side of the pressure chamber 31 opposite to the nozzle plate 50 is blocked by the vibration plate 30.

[0067] The plurality of pressure chambers 31 store the liquid supplied from the common chamber 32 , and are deformed by the vibration of the vibration plate 30 forming a part of the pressure chambers 31 , so that the liquid is ejected from the nozzles 51 .

[0068] The nozzle plate 50 is formed of a metal such as SUS or Ni or a resin material such as polyimide and has a thickness of about 10 μm to 100 μm. The nozzle plate 50 is disposed on one side of the flow channel substrate 405 to cover one opening of the pressure chamber 31 .

[0069] A plurality of nozzles 51 are arranged in a first direction that is the same as the direction in which the pressure chambers 31 are arranged in parallel, forming a nozzle row. For example, two rows of nozzles 51 are provided, and each nozzle 51 is provided at a position corresponding to the plurality of pressure chambers 31 arranged in two rows. In the present embodiment, the nozzles 51 are provided at the end positions of the pressure chambers 31 in the extending direction.

[0070] The frame portion 60 is a structure joined to the vibration plate 30 together with the piezoelectric elements 21 and 22. The frame portion 60 is provided on the side of the vibration plate 30 of the piezoelectric elements 21 and 22 opposite to the flow path substrate 405, and is arranged adjacent to the actuator 20 in the present embodiment, for example. The frame portion 60 is joined to the other side of the vibration plate 30, and is provided between the vibration plate 30 and the substrate 10, forming the outer profile of the inkjet head 1. In addition, the frame portion 60 forms a flow path for the liquid inside. In the present embodiment, the frame portion 60 forms the common chamber 32.

[0071] The common chamber 32 is formed inside the frame portion 60 , and communicates with the pressure chamber 31 via the communication portion 33 provided on the vibration plate 30 and the independent flow path.

[0072] The driving circuit 70 includes: FPC71 (Flexible printed circuits), which is connected to the actuator 20 via independent wiring 102 and common wiring 103 on the mounting surface 101 of the substrate 10; a driving IC72, which is mounted on the FPC71; and a printed wiring substrate 73, which is installed on the other end of the FPC71.

[0073] The driving circuit 70 applies a driving voltage to the external electrodes 223 and 224 via the driving IC 72 , thereby driving the piezoelectric element 21 , increasing or decreasing the volume of the pressure chamber 31 , and ejecting droplets from the nozzle 51 .

[0074] The FPC 71 is connected to the mounting surface 101 of the substrate 10 and is connected to the plurality of external electrodes 223 and 224 of the actuator 20 via the individual wirings 102 and the common wirings 103. As the FPC 71, a COF (Chip on Film) on which a driver IC 72 is mounted as an electronic component is used.

[0075] The driving IC 72 is connected to the external electrodes 223 and 224 via the FPC 71. The driving IC 72 is an electronic component used for discharge control.

[0076] The driver IC 72 generates a control signal and a drive signal for causing each driving piezoelectric element 21 to operate. The driver IC 72 generates a control signal for controlling the timing of ink ejection and the selection of the driving piezoelectric element 21 for ejecting ink according to the image signal input from the control unit 116 of the inkjet recording device 100 equipped with the inkjet head 1. In addition, the driver IC 72 generates a voltage, i.e., a drive signal, applied to the driving piezoelectric element 21 according to the control signal from the control unit 116. When the driver IC 72 applies a drive signal to the driving piezoelectric element 21, the driving piezoelectric element 21 is driven to displace the vibration plate 30 and change the volume of the pressure chamber 31. As a result, the ink filled in the pressure chamber 31 generates pressure vibrations. Through the pressure vibration, ink is ejected from the nozzle 51 connected to the pressure chamber 31. It should be noted that the inkjet head 1 can also be set to be able to achieve grayscale expression by changing the amount of ink drops dripping to one pixel. In addition, the inkjet head 1 can also be set to be able to change the amount of ink drops dripping to one pixel by changing the number of ink ejections. In this way, the driving IC 72 is an example of an application unit that applies a driving signal to the driving piezoelectric element 21 .

[0077] For example, the driver IC 72 includes a data buffer, a decoder, and a driver. The data buffer stores printing data in a time series for each driving piezoelectric element 21. The decoder controls the driver for each driving piezoelectric element 21 based on the printing data stored in the data buffer. The driver outputs a driving signal to operate each driving piezoelectric element 21 based on the control output of the decoder. The driving signal is, for example, a voltage applied to each driving piezoelectric element 21.

[0078] The printed wiring board 73 is a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted, and includes a head control circuit 731. The printed wiring board 73 is connected to the control unit 116 of the inkjet recording apparatus 100.

[0079] In the inkjet head 1 constructed as described above, the nozzle plate 50, the frame portion 60, and the flow path portion 40 form an ink flow path having a plurality of pressure chambers 31 connected to the nozzle 51 and a common chamber 32 respectively connected to the plurality of pressure chambers 31. For example, the common chamber 32 is connected to the box, and ink is supplied to each pressure chamber 31 through the common chamber 32. All the driving piezoelectric elements 21 are connected by wiring in a manner that voltage can be applied. For example, when the control unit 116 of the inkjet recording device 100 of the inkjet head 1 applies a driving voltage to the electrodes 221 and 222 through the driving IC 72, the driving piezoelectric element 21 of the driven object vibrates, for example, in the stacking direction, that is, the thickness direction of each piezoelectric layer 211. That is, the driving piezoelectric element 21 vibrates longitudinally.

[0080] Specifically, the control unit 116 applies a driving voltage to the internal electrodes 221 and 222 of the driving piezoelectric element 21 of the driving object, and selectively drives the driving piezoelectric element 21 of the driving object. Then, the deformation in the tensile direction and the deformation in the compressive direction caused by the driving piezoelectric element 21 of the driving object are combined to deform the vibration plate 30, so that the volume of the pressure chamber 31 changes, thereby guiding the liquid from the common chamber 32 and ejecting it from the nozzle 51.

[0081] Reference Figure 4 An example of a method for manufacturing the inkjet head 1 according to the present embodiment is described. First, internal electrodes 221 and 222 are formed on the surface of a sheet-shaped piezoelectric layer 211 made of a piezoelectric material by printing. Then, a plurality of piezoelectric layers 211 on which the internal electrodes 221 and 222 are formed are stacked, and a firing process and a polarization process are performed to form a piezoelectric member 202 as a stacked piezoelectric member.

[0082] Then, the piezoelectric element 21 of the piezoelectric member 202 having the internal electrodes 221 and 222 formed thereon is subjected to polarization treatment in advance, and is then bonded to the mounting surface 101 of the substrate 10 using an adhesive or the like.

[0083] Then, in a state where the piezoelectric member 202 is arranged on the substrate 10, the surfaces of the substrate 10 and the piezoelectric member 202 are surface-processed to shape the mounting surface 101 and the outer surface of the piezoelectric member 202. At this time, a continuous surface without steps is formed from one side surface of the piezoelectric member 202 to the mounting surface 101 of the substrate 10 by mechanical processing such as grinding processing using a grinding wheel. It should be noted that in the case where burrs are formed when using a grinding wheel that can process the substrate 10 and the piezoelectric body, it is preferable to perform surface treatment such as polishing or sandblasting in the finishing process.

[0084] Next, a metal film is formed on the surface including the top face portion and the side face portions 203 and 204 on both sides of the piezoelectric member 202 and the mounting surface 101 of the substrate 10 by electroplating. For example, electrodes are formed by electroless nickel plating or the like on the surface portion including the face portion and the side face portions on both sides of the piezoelectric member 202 and the entire surface of the mounting surface 101 around the actuator 20, thereby forming an electrode layer to become the external electrodes 223 and 224, and forming the substrate electrode layers 11 and 12 on the mounting surface 101 of the substrate 10. Then, a grinding process is applied to the top face portion of the piezoelectric member 202 to remove the electrodes on the top face portion and form a bonding surface of the top face portion. The grinding process ensures the flatness of the top face portion of the piezoelectric member 202 to which the vibration plate 30 is bonded in a subsequent process.

[0085] Next, a plurality of grooves 23 are formed in the actuator 20 by moving a tool such as a diamond cutter in the Z direction and performing cutting processing. For example, the piezoelectric member 202 bonded to the substrate 10 is cut to form the grooves 23 from the top side that is opposite to the substrate 10 side to a predetermined depth, thereby separating the piezoelectric member 202. Through the above operation, a plurality of driving piezoelectric elements 21 and non-driving piezoelectric elements 22 separated by the grooves 23 and arranged side by side at a predetermined pitch are formed.

[0086] Then, the piezoelectric member 202 and the electrode layer on the surface of the substrate 10 are patterned by photolithography, PEP method, etc. to form a predetermined wiring pattern. In the patterning process based on photolithography, for example, after applying a photosensitive resist material, a photomask such as Figure 4 As shown, ultraviolet rays are irradiated from an irradiation head S to perform exposure processing in a predetermined pattern, and the wiring layer is patterned through development processing and etching processing.

[0087] That is, for the wiring layer formed on the surface of the piezoelectric member 202 and the substrate 10 in the entire surface, the area on the side constituting the independent electrode, that is, the area on the outside of the pair of actuators 20 facing each other, is exposed with a prescribed pattern and a prescribed portion is removed, and a patterning process is performed to divide the substrate electrode layer 11 on the one end side of the independent wiring 102 side into a plurality of layers. At this time, the side surface portion 203 on the side of the independent wiring 102 becomes a cone inclined relative to the mounting surface 101, so that the side surface portion 203 forming a continuous surface and the mounting surface 101 of the substrate 10 can be irradiated with light at the same time, and patterning can be performed at the same time. That is, by dividing the electrode layer of the side surface portion 203 of the piezoelectric member 202 formed as a tapered inclined surface and the substrate electrode layer 11 of the mounting surface 101 of the substrate 10 for each element, the external electrode 223 and the independent wiring 102 are patterned.

[0088] The portion of the external electrode 223 on the nozzle plate 50 side of the piezoelectric member 202 is separated by the groove 23 , and the portion on the substrate 10 side is separated by patterning.

[0089] On the other hand, the substrate electrode layer 12 on the other side is not divided by patterning, and continuously forms the common wiring 103. By the above operation, a plurality of individual wirings 102 divided for each element are formed on one side of the piezoelectric member 202, and a continuous common wiring 103 is formed on the other side.

[0090] The FPC 71 on which electronic components such as the driver IC 72 as a control component are mounted is connected to wiring patterns such as the independent wiring 102 and the common wiring 103 formed into a predetermined shape on the substrate 10 through the ACF (anisotropic conductive film) 75. Furthermore, the printed wiring substrate 73 having the head control circuit 731 is connected to the FPC 71. Through the above operation, the mounting portion 76 using the ACF 75 is formed on the substrate 10.

[0091] Furthermore, the vibration plate 30 , the flow path substrates 405 , 406 , and the nozzle plate 50 are stacked and positioned on the actuator 20 via a bonding material, the frame portion 60 is disposed on the outer periphery of the actuator 20 , and these multiple members are bonded to complete the inkjet head 1 .

[0092] Below, refer to Figure 6 An example of an inkjet recording apparatus 100 including the inkjet head 1 will be described. The inkjet recording apparatus 100 includes a housing 111 , a medium supply unit 112 , an image forming unit 113 , a medium discharge unit 114 , a transport device 115 , and a control unit 116 .

[0093] The inkjet recording device 100 is a liquid ejecting device that ejects liquid such as ink while transporting, for example, paper P as an ejection object, i.e., a printing medium, along a prescribed transport path R from a medium supply unit 112 through an image forming unit 113 to a medium discharge unit 114, thereby performing image forming processing on the paper P.

[0094] The housing 111 constitutes the outer shell of the inkjet recording apparatus 100. The housing 111 is provided with a discharge port at a predetermined position thereof for discharging the paper P to the outside.

[0095] The medium supply unit 112 includes a plurality of paper feed cassettes and is configured to be able to stack and hold a plurality of sheets of paper P of various sizes.

[0096] The medium discharge unit 114 includes a paper discharge tray configured to hold the paper P discharged from the discharge port.

[0097] The image forming section 113 includes a support section 117 that supports the paper P, and a plurality of head units 130 that are disposed above the support section 117 to face each other.

[0098] The support portion 117 includes a conveyor belt 118 disposed in an endless shape in a predetermined area where image formation is performed, a support plate 119 supporting the conveyor belt 118 from the rear side, and a plurality of belt rollers 120 disposed on the rear side of the conveyor belt 118 .

[0099] The support portion 117 supports the paper P on a holding surface that is the upper surface of the conveying belt 118 when forming an image, and conveys the conveying belt 118 at a predetermined timing by the rotation of the belt roller 120 to convey the paper P to the downstream side.

[0100] The head unit 130 includes: a plurality of (four-color) inkjet heads 1 ; ink tanks 132 as liquid tanks mounted on the respective inkjet heads 1 ; connection channels 133 connecting the inkjet heads 1 and the ink tanks 132 ; and a supply pump 134 .

[0101] In this embodiment, there are provided inkjet heads 1 for four colors, cyan, magenta, yellow, and black, and ink tanks 132 for storing inks of these colors, respectively. The ink tanks 132 are connected to the inkjet heads 1 via connection channels 133 .

[0102] In addition, a negative pressure control device such as a pump (not shown) is connected to the ink tank 132. The negative pressure control device controls the negative pressure in the ink tank 132 in accordance with the head value of the inkjet head 1 and the ink tank 132, so that the ink supplied to each nozzle 51 of the inkjet head 1 forms a meniscus of a predetermined shape.

[0103] The supply pump 134 is a liquid delivery pump composed of, for example, a piezoelectric pump. The supply pump 134 is provided in the supply flow path. The supply pump 134 is connected to the control circuit 1161 of the control unit 116 via wiring and is configured to be controllable by the control unit 116. The supply pump 134 supplies liquid to the inkjet head 1.

[0104] The transport device 115 transports the paper P along a transport path R from the medium supply unit 112 through the image forming unit 113 to the medium discharge unit 114 . The transport device 115 includes a plurality of guide plate pairs 121 arranged along the transport path R and a plurality of transport rollers 122 .

[0105] Each of the plurality of guide plate pairs 121 includes a pair of plate members that are disposed opposite to each other with the paper P being transported interposed therebetween, and guides the paper P along the transport path R.

[0106] The conveyance roller 122 is driven and rotated by the control of the control unit 116 to convey the paper P to the downstream side along the conveyance path R. It should be noted that sensors for detecting the conveyance status of the paper are arranged at various locations in the conveyance path R.

[0107] The control unit 116 includes: a control circuit 1161 such as a controller, i.e., a CPU (Central Processing Unit); a ROM (Read Only Memory) for storing various programs; a RAM (Random Access Memory) for temporarily storing various variable data or image data; and an interface unit for inputting data from the outside and outputting data to the outside.

[0108] In the inkjet printer 100 configured as described above, when the control unit 116 detects a print instruction from a user through an operation input unit in the interface, for example, the conveying device 115 is driven to convey the paper P, and a print signal is output to the head unit 130 at a predetermined timing, thereby driving the inkjet head 1. As a discharge operation, the inkjet head 1 sends a drive signal to the driver IC 72 based on an image signal corresponding to image data, applies a drive voltage to the internal electrodes 221 and 222, selectively drives the drive piezoelectric element 21 of the discharge object, and vibrates it longitudinally in, for example, the stacking direction, thereby changing the volume of the pressure chamber 31 to discharge ink from the nozzle 51, and form an image on the paper P held on the conveyor belt 118. In addition, as a liquid discharge operation, the control unit 116 supplies ink from the ink tank 132 to the common chamber 32 of the inkjet head 1 by driving the supply pump 134.

[0109] Here, the driving action of driving the inkjet head 1 is described. The inkjet head 1 involved in this embodiment has a driving piezoelectric element 21 arranged opposite to the pressure chamber 31, and these driving piezoelectric elements 21 are connected by wiring so that voltage can be applied. The control unit 116 sends a driving signal to the driving IC 72 according to the image signal corresponding to the image data, and applies a driving voltage to the internal electrodes 221 and 222 of the driving piezoelectric element 21 of the driving object, so that the driving piezoelectric element 21 of the driving object is selectively deformed. Then, by combining the deformation of the tensile direction and the deformation of the compression direction of the vibration plate 30 and changing the volume of the pressure chamber 31, the liquid is ejected.

[0110] For example, the control unit 116 alternately performs a stretching action and a compression action. In the inkjet head 1, when the stretching is performed to increase the internal volume of the target pressure chamber 31, the driving piezoelectric element 21 of the driving target is contracted, and the driving piezoelectric element 21 outside the driving target is not deformed. In addition, when the compression is performed to reduce the internal volume of the target pressure chamber 31 in the inkjet head 1, the target driving piezoelectric element 21 is extended. It should be noted that the non-driving piezoelectric element 22 is not deformed.

[0111] According to the inkjet head 1 and the inkjet recording device 100 involved in the above-mentioned embodiment, by setting the side portion of one side of the actuator 20 to have a trapezoidal shape with an inclined surface, the processability of pattern processing based on light irradiation such as exposure can be improved. In addition, by continuing from the side portion 203 of the actuator 20 to the mounting surface 101, the electrode is easily led out, and the mounting performance can be further improved. For example, in the case where light is irradiated from one direction in the patterning process based on exposure processing such as photolithography, in the case of a structure in which the electrode wiring of the side portion of the actuator is orthogonal to the wiring portion of the mounting surface 101, it is impossible to form a wiring pattern on the side portion, but by setting the angle with the side portion to be greater than 90° and less than 180°, the mounting surface 101 and the side portion 203 can be patterned at the same time.

[0112] In addition, defects caused by welding can be avoided by mounting the components using ACF75 on the mounting surface 101. That is, when welding is used, the adhesion strength between the piezoelectric member and the electrode and the adhesion strength of the welding are low, so when stress is applied to the flexible cable, the welding joint is easily damaged, but by using ACF mounting, the adhesion strength can be ensured and damage can be prevented.

[0113] In addition, compared with the welding installation in which the piezoelectric body is heated through a flexible cable, the load caused by pressurization and heating can be reduced. In addition, in the case of welding installation, when the pressurization becomes insufficient, disconnection due to poor bonding may occur, but by setting it as ACF installation, the bonding property can be improved. Moreover, for example, in the case of welding the surface of the piezoelectric component, the joint surface is constrained by welding, and sometimes the piezoelectric component is difficult to deform, but by setting it as ACF installation, the constraint of welding can be avoided and the deformation characteristics can be improved. In addition, in the case of welding the surface of the piezoelectric component, sometimes the mounting portion is damaged due to the deformation of the piezoelectric component, but by setting it as ACF installation, it can be set to a structure that is not easy to be damaged.

[0114] It should be noted that, for example, in the case of a shared mode structure, since both sides (one surface and the surface on the opposite side) of the piezoelectric member need to be patterned for electrode wiring, it is necessary to set an inclination on both sides, but one side of the actuator 20 involved in this embodiment is a common electrode and does not need to be patterned, so there is no need to set an inclination on the common electrode. That is, it is sufficient to set an inclination on only one side of the actuator 20, so the width of the inkjet head 1 can be reduced, and miniaturization can be achieved.

[0115] It should be noted that the present invention is not limited to the above-described embodiments, and components may be modified and embodied in the implementation stage without departing from the spirit and scope of the present invention.

[0116] The specific materials and structures of the piezoelectric elements 21 and 22 in the above-mentioned embodiment are not limited to those described above, and can be changed as appropriate.

[0117] For example, in the formation of the wiring pattern, other laser patterning can also be used. In this case, the laser can also be irradiated to the surface and the inclined surface at the same time, so the same effect as the above-mentioned embodiment can be obtained.

[0118] The specific shape of the wiring is not limited to the above. For example, although the example in which the extension direction of the wiring pattern of the side surface portion 203 that becomes the inclined surface is consistent with the wiring pattern of the mounting surface 101 of the substrate 10 is shown, it is not limited to this. For example, it can also be a reverse pattern corresponding to the reflected light reflected from the inclined surface to the substrate. Or the extension direction can also be different.

[0119] For example, when the direction of the wiring pattern of the portion close to the piezoelectric member 202 is inconsistent, the influence of the reflected light between the side surface 203 and the mounting surface 101 during exposure can be eliminated by adjusting the angle of the inclined surface. In this case, the angle at which the side surface 203 forming the inclined surface intersects with the mounting surface 101 is preferably greater than 135°. That is, as another embodiment, Figure 5As shown, by setting the inclination angle θ to be larger than 135°, it is possible to adopt a configuration in which there are few restrictions on the extending direction of each wiring of the wiring pattern and the degree of freedom of wiring is high.

[0120] It should be noted that the patterning of the independent wiring 102 may be performed simultaneously with the patterning of the inclined external electrode 223 or may be performed in another step.

[0121] In addition, in the above-mentioned embodiment, the piezoelectric body layer 211 is stacked in multiple layers and the piezoelectric element 21 is driven by the longitudinal vibration (d33) in the stacking direction, but the present invention is not limited to this. For example, the piezoelectric element 21 can be driven by a single-layer piezoelectric member, or by a transverse vibration that is displaced in the d31 direction.

[0122] The arrangement of the nozzles 51 and the pressure chambers 31 is not limited to the above-mentioned embodiment. For example, the nozzles 51 may be arranged in two or more rows. In addition, an air chamber serving as a dummy chamber may be formed between the plurality of pressure chambers 31. The inkjet head is not limited to the circulation type, and may also be a non-circulation type.

[0123] In addition, the configurations and positional relationships of various components including the flow path portion 40 , the nozzle plate 50 , and the frame portion 60 are not limited to the above-described examples, and can be appropriately changed.

[0124] Furthermore, in the above embodiment, an example is shown in which two actuators 20 are arranged in parallel on the substrate 10 , but the present invention is not limited thereto, and the number of the actuators 20 may be singular or may be three or more.

[0125] The liquid to be discharged is not limited to printing ink, and may be, for example, a device that discharges a liquid containing conductive particles for forming a wiring pattern of a printed wiring board.

[0126] In addition, in the above-mentioned embodiment, an example of the inkjet head 1 being used in a liquid ejecting device such as an inkjet recording device is shown, but it is not limited to this, and can also be used for example in a 3D printer, industrial manufacturing machinery, and medical use, and can achieve miniaturization, lightness, and cost reduction.

[0127] According to at least one of the embodiments described above, it is possible to provide a liquid ejection head and a liquid ejection device that can improve the mountability.

[0128] Although several embodiments are described, these embodiments are only presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the purpose of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are also included in the invention described in the claims and their equivalents.

Claims

1. A liquid ejection head, characterized in that: have: A substrate having a wiring surface; A piezoelectric component is provided on the wiring surface of the substrate and has a side surface that is inclined at an angle greater than 90° and less than 180° relative to the wiring surface; a vibration plate disposed opposite to the substrate and arranged on the side of the piezoelectric member opposite to the substrate; as well as The electrode wiring is formed on the inclined surface of the piezoelectric member.

2. The liquid ejection head according to claim 1, wherein: The liquid ejection head comprises: a flow path portion forming a pressure chamber disposed opposite to the vibration plate; and The substrate wiring is formed on the wiring surface of the substrate and is connected to the electrode wiring formed on the side surface.

3. The liquid ejection head according to claim 2, wherein: An angle between the one side surface of the piezoelectric member and the wiring surface of the substrate is larger than 135° and is larger than an angle between the other side surface of the piezoelectric member and the wiring surface of the substrate.

4. The liquid ejection head according to claim 2, wherein: The substrate includes a mounting portion on the wiring surface, and the mounting portion mounts a component on the substrate wiring via an anisotropic conductive film.

5. The liquid ejection head according to any one of claims 1 to 4, wherein The piezoelectric member is a stacked piezoelectric member composed of stacked piezoelectric bodies.

6. The liquid ejection head according to any one of claims 1 to 4, wherein: The piezoelectric component includes a dummy layer.

7. The liquid ejection head according to claim 5, wherein: The piezoelectric component includes a dummy layer.

8. The liquid ejection head according to any one of claims 1 to 4, wherein: The thickness of the vibration plate along the vibration direction is 5 μm to 15 μm.

9. The liquid ejection head according to claim 5, wherein: The thickness of the vibration plate along the vibration direction is 5 μm to 15 μm.

10. A liquid ejection device, characterized in that: A liquid ejection head according to any one of claims 1 to 9 is provided.

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