JP7724149B2 - Liquid ejection head - Google Patents

Description

An embodiment of the present invention relates to a liquid ejection head.

Conventionally, liquid ejection heads such as inkjet heads have been known that have piezoelectric ceramics on a ceramic substrate, with multiple partition walls formed at predetermined intervals and the spaces between the partition walls serving as ink flow paths. In liquid ejection heads, drive electrodes are formed on the side surfaces of each partition wall, and the end faces of the partition walls have inclined surfaces that extend outward from their tops to their bottoms. The electrodes of the liquid ejection head are formed as patterns on the inclined surfaces of the partition walls and on the substrate as lead lines.

For example, in order to increase the speed of ink ejection, liquid ejection heads use an independent drive structure with grooves for liquid ejection and grooves that do not eject liquid. In one example of a liquid ejection head with an independent drive structure, the electrodes of the liquid ejection grooves are bundled together in the center of the substrate to form a common GND electrode, and the electrodes of the grooves that do not eject liquid are pulled out to the driver IC side.

For example, when ink is ejected by simultaneously driving all nozzles, if the resistance of the common GND electrode is high, differences in the drive waveform will be observed between the ends and center of the groove array, which could result in poor print quality such as dot diameter and linearity.

Japanese Patent Application Laid-Open No. 2011-37057

The problem that this invention aims to solve is to provide a liquid ejection head that can reduce the resistance value of the electrodes.

The liquid ejection head of the embodiment includes an actuator, a substrate, and an electrode. The actuator has a plurality of pressure chambers arranged in one direction. The substrate is provided with the actuator. The electrode is formed on the substrate and the actuator. The conductor portion of the electrode formed on the substrate is formed from a multilayer film including a Ni sputtered film, an electroless Ni plated film, a first electrolytic metal plated film, and a second electrolytic metal plated film of a metal different from the first electrolytic metal plated film. The conductor portion of the electrode formed on the actuator is formed from the Ni sputtered film and the electroless Ni plated film. The electrode drives the pressure chamber.

FIG. 1 is a perspective view showing a configuration of a liquid ejection head according to an embodiment. FIG. 2 is a bottom view showing the configuration of the liquid ejection head according to the embodiment. FIG. 2 is a bottom view illustrating the configuration of the liquid ejection head according to the embodiment, with some parts omitted. FIG. 2 is a perspective view showing the configuration of a head main body of the liquid ejection head according to the embodiment. FIG. 2 is a cross-sectional view showing the configuration of a head main body according to the embodiment. FIG. 2 is a plan view showing the configuration of a head main body according to the embodiment. FIG. 2 is a cross-sectional view showing the configuration of a head main body according to the embodiment, with some parts omitted. FIG. 2 is a cross-sectional view showing the configuration of a substrate and electrodes of a head main body according to the embodiment. FIG. 2 is a cross-sectional view showing the configuration of an actuator and electrodes of the head main body according to the embodiment. 4 is a flowchart showing an example of a method for manufacturing a liquid ejection head according to an embodiment. FIG. 1 is an explanatory diagram showing the configuration of a liquid ejection device according to an embodiment.

A liquid ejection head 1 according to an embodiment and a liquid ejection device 2 using the liquid ejection head 1 will be described below with reference to FIGS. 1 to 11. FIG. 1 is a perspective view showing the configuration of the liquid ejection head 1 according to the first embodiment, and FIG. 2 is a bottom view showing the configuration of the liquid ejection head 1. FIG. 3 is a bottom view showing the configuration of the liquid ejection head 1 with the nozzle plate 114 omitted. FIG. 4 is a perspective view showing the configuration of the head body 11 of the liquid ejection head 1 with a portion of the nozzle plate 114 cut away, and FIG. 5 is a cross-sectional view showing the configuration of the head body 11. FIG. 6 is a plan view showing the configuration of the substrate 111, actuator 113, and electrode 117 of the head body 11. FIG. 7 is a cross-sectional view showing the configuration of the substrate 111, actuator 113, and electrode 117 of the head body 11. FIG. 8 is a cross-sectional view showing the configuration of the substrate 111 and electrode 117 of the head body 11, and FIG. 9 is a cross-sectional view showing the configuration of the actuator 113 and electrode 117 of the head body 11. Figure 10 is a flow chart showing an example of forming the electrodes 117 of the head body 11 as an example of a method for manufacturing the liquid ejection head 1. Figure 11 is an explanatory diagram showing the configuration of a liquid ejection device 2 using the liquid ejection head 1. Note that for the purpose of explanation, the configuration is enlarged, reduced, or omitted in each figure as appropriate.

The liquid ejection head 1 is a share-mode inkjet head provided in a liquid ejection device 2, such as the inkjet recording device shown in Figure 11. The liquid ejection head 1 is provided in a head unit 2130 that includes a supply tank 2132 as a liquid storage section provided in the liquid ejection device 2.

The liquid ejection head 1 is supplied with ink as a liquid stored in a supply tank 2132. The liquid ejection head 1 may be a non-circulating head that does not circulate ink, or a circulating head that circulates ink. In this embodiment, the liquid ejection head 1 will be described using an example of a non-circulating head. The liquid ejection head 1 is also connected to a temperature adjustment device 2116 provided in the liquid ejection device 2, and is supplied with temperature adjustment liquid (temperature adjustment water) that controls the temperature of the ink.

As shown in Figures 1 to 4, the liquid ejection head 1 comprises a head body 11, a manifold unit 12, a circuit board 13, and a cover 14. For example, the liquid ejection head 1 is a side-shooter type four-row integrated structure head having two sets of head bodies 11, each having a pair of actuators 113.

The head body 11 ejects liquid. As shown in Figures 3 to 7, the head body 11 includes a substrate 111, a frame member 112, an actuator 113 having multiple pressure chambers 1131 and multiple air chambers 1132, and a nozzle plate 114. The head body 11 has a common liquid chamber 116 that communicates with the multiple pressure chambers 1131 of the actuator 113.

The head body 11 also has electrodes 117 on the substrate 111 and actuator 113 that drive multiple pressure chambers 1131 of the actuator 113.

In this embodiment, an example will be described in which the head main body 11 has two actuators 113, and the common liquid chamber 116 has one first common liquid chamber 1161 and two second common liquid chambers 1162. The common liquid chamber 116 has, for example, a first common liquid chamber 1161 that communicates with one opening of the multiple pressure chambers 1131 of the actuator 113, a second common liquid chamber 1162 that communicates with the other opening of the multiple pressure chambers 1131 of the actuator 113, and a third common liquid chamber 1163 that connects both ends of the first common liquid chamber 1161 to both ends of the two second common liquid chambers 1162.

The substrate 111 is formed, for example, from a ceramic material in the shape of a rectangular plate. The substrate 111 is formed, for example, in a rectangular shape that is long in one direction. A wiring pattern that becomes part of the electrode 117 is formed on one surface of the substrate 111. As a specific example, a wiring pattern that becomes part of multiple individual electrodes 118 (described below) of the electrode 117, and a wiring pattern that becomes part of a single common electrode 119 are formed on one surface of the substrate 111. A pair of actuators 113 are provided on one surface of the substrate 111, lined up in the short direction of the substrate 111. The one surface of the substrate 111 refers to one surface of the substrate 111. The substrate 111 has, for example, a single supply port 1111 and multiple discharge ports 1112. The supply port 1111 and the discharge ports 1112 are through holes that penetrate between the two main surfaces of the substrate 111.

The supply port 1111 is an inlet for supplying ink to the first common liquid chamber 1161. The supply port 1111 is a through-hole formed in the center of the substrate 111 in the short direction. The supply port 1111 extends along the longitudinal direction of the substrate 111. In other words, the supply port 1111 is, for example, an elongated hole that is long in one direction along the longitudinal direction of the actuator 113 and the longitudinal direction of the first common liquid chamber 1161. The supply port 1111 is provided between the pair of actuators 113 and opens at a position facing the first common liquid chamber 1161.

The discharge port 1112 is an outlet for discharging ink from the second common liquid chamber 1162. Multiple discharge ports 1112, for example, four, are provided. Each discharge port 1112 is provided, for example, in two third common liquid chambers 1163. Note that multiple discharge ports 1112 may also be provided in the second common liquid chamber 1162.

The frame member 112 is fixed to one main surface of the substrate 111 with an adhesive or the like. The frame member 112 surrounds the supply port 1111, multiple discharge ports 1112, and actuator 113 provided in the substrate 111. For example, the frame member 112 has a stepped structure.

For example, the frame member 112 is formed in a rectangular frame shape, forming an opening that is long in one direction along the longitudinal direction of the frame member 112. A pair of actuators 113, a supply port 1111, and four discharge ports 1112 are arranged in the opening of the frame member 112.

A pair of actuators 113 are adhered to the mounting surface of the substrate 111. The pair of actuators 113 are arranged in two rows on the substrate 111, sandwiching the supply port 1111 between them. The actuators 113 are formed in the shape of a plate that is long in one direction. The actuators 113 are placed within the opening of the frame member 112 and adhered to the main surface of the substrate 111.

As shown in Figures 3 and 6, the actuator 113 has a plurality of pressure chambers 1131 arranged at equal intervals in the longitudinal direction, and air chambers 1132 arranged at equal intervals in the longitudinal direction and between adjacent pressure chambers 1131. In other words, the actuator 113 has a plurality of pressure chambers 1131 and air chambers 1132 arranged alternately along the longitudinal direction.

The surface of the actuator 113 opposite the substrate 111 is bonded to the nozzle plate 114. The actuators 113 are arranged in a row at equal intervals along the longitudinal direction, and multiple grooves are formed along a direction perpendicular to the longitudinal direction. The multiple grooves form multiple pressure chambers 1131 and multiple air chambers 1132. In other words, the actuator 113 has multiple piezoelectric bodies 1133 that are driving elements arranged in a row at equal intervals along the longitudinal direction and that form walls that form the grooves between them. The multiple piezoelectric bodies 1133 form multiple pressure chambers 1131 and multiple air chambers 1132 between adjacent piezoelectric bodies 1133, and the volume of the pressure chambers 1131 changes when a driving voltage is applied.

For example, the width of the actuator 113 in the short side direction gradually increases from the top side toward the substrate 111 side. The cross-sectional shape of the actuator 113 in the direction perpendicular to the longitudinal direction (short side direction) is formed into a trapezoidal shape. That is, the actuator 113 has an inclined surface 1134 on the side portion in the short side direction. The side portion (inclined surface 1134) is arranged opposite the first common liquid chamber 1161 and the second common liquid chamber 1162.

As a specific example, the actuator 113 is formed from a laminated piezoelectric component in which two rectangular piezoelectric material plates, each elongated in one direction, are bonded together facing each other so that their polarization directions are opposite. Here, the piezoelectric material is, for example, PZT (lead zirconate titanate). The actuator 113 is bonded to the mounting surface of the substrate 111, for example, with a thermosetting epoxy adhesive. The actuator 113 then forms an inclined surface 1134, for example, by cutting or other processes. Additionally, the surfaces of the substrate 111 and the actuator 113, on which the multiple individual electrodes 118 and common electrode 119 of the electrode 117 are patterned, are polished to form a polished surface, for example, by polishing. For example, the polished surface is formed on the inclined surface 1134 of the actuator 113 and on the substrate 111 at the base of the inclined surface 1134. Furthermore, the actuator 113 is formed, for example, by cutting, with multiple grooves that form multiple pressure chambers 1131 and multiple air chambers 1132, and with piezoelectric bodies (drive elements) 1133 that serve as side walls separating adjacent grooves.

In addition, the actuator 113 is formed with wiring patterns that form part of multiple individual electrodes 118 and wiring patterns that form part of one or more common electrodes 119.

The pressure chamber 1131 deforms when the liquid ejection head 1 performs operations such as printing, causing ink to be ejected from the nozzle 1141. The pressure chamber 1131 has an inlet that opens to the first common liquid chamber 1161 and an outlet that opens to the second common liquid chamber 1162. Ink flows into the pressure chamber 1131 from the inlet and flows out from the outlet. Note that the pressure chamber 1131 may also be configured so that ink flows in from both the inlet and outlet openings described above.

As shown by the dashed lines in FIG. 7 , the air chamber 1132 is separated from the first common liquid chamber 1161 and the second common liquid chamber 1162 by having its inlet and outlet sides blocked by liquid-proof walls 1135 made of a photosensitive resin or the like. As a specific example, the liquid-proof walls 1135 of the air chamber 1132 are formed by injecting ultraviolet-curable resin into the groove that forms the air chamber 1132, and then using a mask plate or the like to irradiate the necessary portions, such as both ends of the groove (the inlet and outlet sides), with ultraviolet light. Such liquid-proof walls 1135 prevent ink from entering the air chamber 1132. Furthermore, the air chamber 1132 is blocked by the nozzle plate 114, and no nozzles 1141 are located there. Therefore, ink does not flow into the air chamber 1132.

The nozzle plate 114 is formed in a plate shape. The nozzle plate 114 is fixed with an adhesive or the like to the main surface of the frame member 112 opposite the substrate 111. The nozzle plate 114 has a plurality of nozzles 1141 formed in positions facing the plurality of pressure chambers 1131. In this embodiment, the nozzle plate 114 has two nozzle rows 1142 in which a plurality of nozzles 1141 are aligned in one direction.

The first common liquid chamber 1161 is formed between the center of the pair of actuators 113, excluding both ends, and forms an ink flow path from the supply port 1111 to one opening of the multiple pressure chambers 1131 of each actuator 113. The first common liquid chamber 1161 extends along the longitudinal direction of the actuator 113.

The second common liquid chamber 1162 is formed between each actuator 113 and the frame member 112. The second common liquid chamber 1162 forms an ink flow path from the third common liquid chamber 1163 to the other opening of the multiple pressure chambers 1131. The second common liquid chamber 1162 extends along the longitudinal direction of the actuator 113.

The third common liquid chamber 1163 is adjacent to both longitudinal ends of the actuator 113, for example. The third common liquid chamber 1163 connects the first common liquid chamber 1161 and the two second common liquid chambers 1162 at both longitudinal ends of the pair of actuators 113. The third common liquid chamber 1163 forms a flow path for part of the ink that runs from the first common liquid chamber 1161 to the second common liquid chamber 1162 without passing through the multiple pressure chambers 1131 of each actuator 113. The third common liquid chamber 1163 also forms a flow path for ink from the first common liquid chamber 1161 and the two second common liquid chambers 1162 to the outlet 1112.

The electrode 117 is an electrode film. The electrode 117 includes, for example, multiple individual electrodes 118 that drive each of the multiple pressure chambers 1131, and one or more common electrodes 119 that simultaneously drive the multiple pressure chambers 1131.

As shown in Figures 7 to 9, the electrode 117 has a first electrode portion 1171, which is a conductive portion formed on the upper surface of the substrate 111 and the inclined surface 1134 of the actuator 113, and a second electrode portion 1172, which is a conductive portion formed on the bottom and side surfaces of the multiple pressure chambers 1131 and multiple air chambers 1132 of the actuator 113.

The first electrode portion 1171 is a wiring pattern (lead line). The first electrode portion 1171 is formed of a multilayer film. As shown in FIG. 8, the first electrode portion 1171 includes a Ni sputtered film 11731, an electroless Ni plated film 11732, a first electrolytic metal plated film 11733, and a second electrolytic metal plated film 11734 of a metal different from the first electrolytic metal plated film 11733.

The first electrolytic metal plating film 11733 is, for example, an electrolytic Ni plating film. Hereinafter, the first electrolytic metal plating film 11733 will be described as an electrolytic Ni plating film 11733. The second electrolytic metal plating film 11734 is, for example, an electrolytic Au plating film. Hereinafter, the second electrolytic metal plating film 11734 will be described as an electrolytic Au plating film 11734.

The second electrode portion 1172 is formed from a multilayer film having fewer layers than the first electrode portion 1171. As shown in FIG. 9, the second electrode portion 1172 is formed from a multilayer film in which the conductor portion formed in the groove between adjacent piezoelectric bodies 1133 of the actuator 113 is formed from a Ni sputtered film 11731 and an electroless Ni plated film 11732. The second electrode portion 1172 is provided continuously with the corresponding first electrode portion 1171.

In other words, the first electrode portion 1171 is provided with an electrolytic Ni plating film (first electrolytic metal plating film) 11733 and an electrolytic Au plating film (second electrolytic metal plating film) 11734, and therefore has a thicker film thickness and a lower resistance value than the second electrode portion 1172.

Next, as an example of a method for manufacturing the liquid ejection head 1, an example of forming the electrode 117 will be explained using the flow chart shown in Figure 10.

First, sputtering is performed on predetermined regions of the substrate 111 and the actuator 113 to form a Ni sputtered film 11731 (ACT 1). As a specific example, the Ni sputtered film 11731 is formed on the substrate 111 including the polished surface, the inclined surface 1134 of the actuator 113, and the inner surfaces of the multiple piezoelectric elements 1133 that form the multiple pressure chambers 1131 and multiple air chambers 1132 of the actuator 113. At this time, the Ni sputtered film 11731 is formed in an area that includes the range where the multiple individual electrodes 118 and common electrode 119 are provided.

Next, electroless Ni plating film 11732 is formed on Ni sputtered film 11731 using electroless plating (ACT 2). For example, electroless Ni plating film 11732 is formed using Ni sputtered film 11731 as a catalyst.

Next, an electrolytic Ni plating film 11733 is formed on the electroless Ni plating film 11732 using electrolytic plating (ACT 3). At this time, because the width of the grooves formed between the multiple piezoelectric elements 1133 is small, the electrolytic Ni plating film 11733 is formed only on the electroless Ni plating film 11732 formed on the substrate 111 and the inclined surface 1134 of the actuator 113. In other words, by using electrolytic plating, the electrolytic Ni plating film 11733 is formed only on the electroless Ni plating film 11732 in the area where the first electrode portion 1171 is to be provided.

Next, the electrodes formed by the Ni sputtered film 11731, electroless Ni plated film 11732, and electrolytic Ni plated film 11733 are patterned using photolithography or the like (ACT 4). The electrode pattern at this time is, for example, the pattern of the multiple individual electrodes 118 and common electrode 119 formed on the substrate 111 and actuator 113.

Next, an electrolytic Au plating film 11734 is formed on the patterned electrolytic Ni plating film 11733 using electrolytic plating (ACT 5). At this time, because the width of the grooves formed between the multiple piezoelectric elements 1133 is small, the electrolytic Au plating film 11734 is formed on the substrate 111 and the inclined surface 1134 of the actuator 113, and is formed only on the patterned electroless Ni plating film 11732. Through these example processes, an electrode 117 is formed that includes a wiring pattern of multiple individual electrodes 118 and a common electrode 119, and that includes first electrode portions 1171 and second electrode portions 1172 that have different thicknesses and different layer structures.

The multiple individual electrodes 118 apply a driving voltage individually to the multiple piezoelectric elements 1133, which are piezoelectric elements. The multiple individual electrodes 118 individually deform each pressure chamber 1131. The individual electrodes 118 are formed by a wiring pattern formed on the substrate 111 and a wiring pattern formed on the actuator 113. The individual electrodes 118 are a wiring pattern formed by a first electrode portion 1171 and a second electrode portion 1172. The multiple individual electrodes 118 are connected to the circuit board 13.

7, multiple individual electrodes 118 are formed on the inner surfaces of each pressure chamber 1131, the inclined surface 1134 of the actuator 113, and the substrate 111. Specifically, the individual electrodes 118 are formed by the second electrode portion 1172 on the side surfaces of the piezoelectric body 1133 that forms the pressure chamber 1131, and on the bottom surface of the pressure chamber 1131. The individual electrodes 118 are also formed by the first electrode portion 1171 on the inclined surface 1134 and the polished surface of the substrate 111. The individual electrodes 118 extend from within the pressure chamber 1131 to the ends of the substrate 111 in the short direction, with their ends positioned at the connection portions 1116 to which the circuit board 13 of the substrate 111 is connected. The individual electrodes 118 are provided so as to be in close contact with the bottom of the pressure chamber 1131 and the surface of the piezoelectric member that forms the piezoelectric body 1133. The individual electrodes 118 are formed, for example, from a nickel thin film. For example, the individual electrodes 118 on the substrate 111 are covered on the underside of the frame member 112 with adhesive that bonds the frame member 112 to the substrate 111.

The common electrode 119 applies the same drive voltage to all of the multiple piezoelectric bodies 1133. The common electrode 119 simultaneously deforms the multiple pressure chambers 1131. The common electrode 119 is formed by a wiring pattern formed on the substrate 111 and a wiring pattern formed on the actuator 113. The common electrode 119 is a wiring pattern that extends from the inner surface of the supply port 1111 of the substrate 111 to the piezoelectric bodies 1133 that form the multiple air chambers 1132. The common electrode 119 is connected to the circuit board 13.

7, the common electrode 119 is formed on the substrate 111, avoiding the inner surfaces of each air chamber 1132, the inclined surfaces 1134 of the actuators 113, and the areas where the individual electrodes 118 are formed. Specifically, the common electrode 119 is formed by the second electrode portion 1172 on the side surfaces of the piezoelectric elements 1133 that form each air chamber 1132 and on the bottom surface of each air chamber 1132. The common electrode 119 is also formed by the first electrode portion 1171 on the inclined surfaces 1134 from within each air chamber 1132 toward the center of the substrate 111, on the polished surface of the substrate 111 between the pair of actuators 113, and on the inner surface of the supply port 1111. The common electrode 119 extends to the ends of the substrate 111 in the shorter direction, with its ends positioned at the connection portions 1116 to which the circuit board 13 of the substrate 111 is connected.

In other words, the common electrode 119 is integrally provided on the inclined surface 1134 of the actuator 113 and the inner surface of the multiple air chambers 1132, extending from the connection portion 1116 formed at the end of the substrate 111 in the lateral direction to the center of the substrate 111 in the lateral direction between the pair of actuators 113.

As shown in Figures 1, 2, 4, and 5, the manifold unit 12 includes a manifold 121, a top plate 122, an ink supply pipe 123, an ink discharge pipe 124, and a pair of temperature control pipes: a temperature control water supply pipe 125 and a temperature control water discharge pipe. The number of ink supply pipes 123, ink discharge pipes 124, temperature control water supply pipes 125, and temperature control water discharge pipes can be set as appropriate.

The manifold 121 is formed in a plate or block shape. As shown in FIG. 5, the manifold 121 includes a supply flow path 1211 that is continuous with the supply port 1111 of the substrate 111 and forms a liquid supply flow path, a discharge flow path that is continuous with the discharge port 1112 of the substrate 111 and forms a liquid discharge flow path, and a temperature control flow path 1213 that forms a flow path for a temperature control fluid.

One main surface of the manifold 121 is fixed to the main surface of the substrate 111. A top plate 122 is fixed to the main surface of the manifold 121 opposite the main surface to which the substrate 111 is fixed. Also, for example, ink supply pipes 123, ink discharge pipes 124, temperature-controlled water supply pipes 125, and temperature-controlled water discharge pipes are fixed to the manifold 121 via the top plate 122.

The supply flow path 1211 is a flow path formed in the manifold 121 by holes or grooves. The supply flow path 1211 fluidly connects the ink supply pipe 123 and the supply port 1111 of the substrate 111.

The discharge flow path is a flow path formed in the manifold 121 by holes or grooves. The discharge flow path fluidly connects the ink discharge tube 124 and the discharge port 1112 of the substrate 111.

The temperature control flow path 1213 is a flow path formed in the manifold 121 by holes or grooves. The temperature control flow path 1213 fluidly connects the temperature control water supply pipe 125 and the temperature control water discharge pipe.

Both ends of the temperature control flow path 1213 are openings that connect to a temperature control water supply pipe 125 and a temperature control water discharge pipe provided on one main surface of the manifold 121. The temperature control flow path 1213 is also formed to enable heat exchange with the substrate 111 fixed to the manifold 121.

The top plate 122 is provided on the side of the manifold 121 opposite to the side on which the substrate 111 is provided. By covering the manifold 121, the top plate 122 seals the supply flow path 1211, the discharge flow path, and the temperature adjustment flow path 1213.

The top plate 122 also has openings that connect the tubes 123, 124, and 125 and allow communication between the tubes 123, 124, and 125 and the flow paths 1211 and 1213.

The ink supply pipe 123 is connected to the supply flow path 1211. The ink discharge pipe 124 is connected to the discharge flow path. The temperature control water supply pipe 125 and the temperature control water discharge pipe are connected to the primary and secondary sides of the temperature control flow path 1213.

As shown in FIG. 4, the circuit board 13 comprises a wiring film 131, one end of which is connected to the connection portion 1116 of the substrate 111, a driver IC 132 mounted on the wiring film 131, and a printed wiring board 133 mounted on the other end of the wiring film 131.

The circuit board 13 drives the actuator 113 by applying a drive voltage to the wiring pattern of the actuator 113 via the driver IC 132, increasing or decreasing the volume of the pressure chamber 1131 and ejecting droplets from the nozzle 1141.

The wiring film 131 is connected to the multiple individual electrodes 118 and the common electrode 119. For example, the wiring film 131 is an ACF (anisotropic conductive film) that is fixed to the connection portion of the substrate 111 by thermocompression bonding or the like. For example, multiple wiring films 131 are provided for one head body 11. In this embodiment, two wiring films 131 are connected to one actuator 113. The wiring film 131 is, for example, a COF (chip on film) on which a driver IC 132 is mounted.

The driver IC 132 is connected to the multiple individual electrodes 118 and the common electrode 119 via the wiring film 131. Note that the driver IC 132 may also be connected to the multiple individual electrodes 118 and the common electrode 119 by other means, such as ACP (anisotropic conductive paste), NCF (non-conductive film), and NCP (non-conductive paste), rather than the wiring film 131.

The printed wiring board 133 is a PWA (Printing Wiring Assembly) on which various electronic components and connectors are mounted.

The cover 14 includes, for example, an outer shell 141 that covers the side surfaces of the pair of head bodies 11, the manifold unit 12, and the circuit board 13, and a mask plate 142 that covers a portion of the pair of head bodies 11 on the nozzle plate 114 side.

The outer shell 141 exposes, for example, the ink supply pipe 123, ink discharge pipe 124, temperature-controlled water supply pipe 125, and temperature-controlled water discharge pipe of the manifold unit 12, as well as the end of the circuit board 13.

The mask plate 142 covers the pair of head bodies 11 except for the multiple nozzles 1141 and the areas surrounding the multiple nozzles 1141 on the nozzle plate 114.

The liquid ejection head 1 configured in this manner has, on the head body 11, multiple individual electrodes 118 that can apply a drive voltage to each piezoelectric element 1133 individually, and a common electrode 119 that can apply a drive voltage to all piezoelectric elements 1133.

As a result, the liquid ejection head 1 can selectively drive multiple pressure chambers 1131 individually or in common. When a pressure chamber 1131 is driven, the pressure chamber 1131 undergoes shear mode deformation, and the ink supplied to the pressure chamber 1131 is pressurized. As a result, the liquid ejection head 1 can selectively eject pressurized ink from the nozzle 1141 facing the deformed pressure chamber 1131.

Furthermore, the conductive portions of the electrode 117 on the substrate 111 and on the inclined surface 1134 of the actuator 113 are formed of a first electrode portion 1171, which is a multilayer film formed of a Ni sputtered film 11731, an electroless Ni plated film 11732, an electrolytic Ni plated film (first electrolytic metal plated film) 11733, and an electrolytic Au plated film (second electrolytic metal plated film) 11734. Furthermore, the conductive portions of the electrode 117 formed on the surfaces of the grooves between the piezoelectric bodies 1133 of the actuator 113 are formed of a second electrode portion 1172, which is a multilayer film formed of a Ni sputtered film 11731 and an electroless Ni plated film 11732. Therefore, the electrode 117 can reduce the resistance value of the first electrode portion 1171, which is the wiring pattern leading to the piezoelectric body 1133, which is the driving element. In particular, by forming the first electrode portion 1171 on the common electrode 119, it is possible to prevent differences in ejection performance between the center and end portions in the arrangement direction of the nozzles 1141 of the head main body 11 when driving multiple pressure chambers 1131.

In addition, the conductivity of the first electrode portion 1171 is reduced by the electrolytic Ni plating film 11733 formed by electrolytic plating. Therefore, by providing the electrolytic Ni plating film 11733, the electrical resistance of the first electrode portion 1171 can be reduced.

Furthermore, by providing the electrolytic Ni plating film 11733, the thickness of the electrolytic Au plating film 11734 can also be reduced. That is, there are limitations to thickening the electrolytic Au plating film 11734 because the high malleability of Au can cause burrs and other problems in the finished product after machining. Furthermore, from the perspective of production efficiency, it is difficult to reduce the resistance of the Ni sputtered film 11731 and the electroless Ni plating film 11732 by thickening them. However, by providing the first electrode portion 1171 of the embodiment with the electrolytic Ni plating film 11733, which has lower electrical resistance than the electroless Ni plating film 11732, the electrical resistance can be reduced even if the electrolytic Au plating film 11734 is made thinner, and the film can be formed with high production efficiency.

The inkjet recording device 2 having the liquid ejection head 1 will be described below with reference to Figure 11. The inkjet recording device 2 comprises a housing 2111, a medium supply unit 2112, an image forming unit 2113, a medium ejection unit 2114, a transport device 2115 which is a support device, a temperature adjustment device 2116, a maintenance device 2117, and a control unit 2118. The inkjet recording device 2 also comprises a temperature adjustment device which adjusts the temperature of the ink supplied to the liquid ejection head 1.

The inkjet recording device 2 is an inkjet printer that performs an image formation process on a recording medium, such as paper P, by ejecting a liquid such as ink while transporting the recording medium, such as paper P, along a predetermined transport path 2001 that runs from the medium supply unit 2112 through the image forming unit 2113 to the medium discharge unit 2114.

The medium supply unit 2112 has multiple paper feed cassettes 21121. The image forming unit 2113 has a support unit 2120 that supports paper and multiple head units 2130 arranged above and facing the support unit 2120. The medium discharge unit 2114 has a paper discharge tray 21141.

The support section 2120 includes a conveyor belt 21201 that is looped in a predetermined area where image formation is performed, a support plate 21202 that supports the conveyor belt 21201 from the back side, and multiple belt rollers 21203 that are provided on the back side of the conveyor belt 21201.

The head unit 2130 includes multiple inkjet heads (liquid ejection heads 1), multiple supply tanks 2132 (liquid tanks) mounted on each liquid ejection head 1, a pump 2134 that supplies ink, and a connection flow path 2135 that connects the liquid ejection heads 1 and the supply tanks 2132.

In this embodiment, the liquid ejection heads 1 are provided in four colors: cyan, magenta, yellow, and black, and four supply tanks 2132 that contain ink of each color. The supply tanks 2132 are connected to the liquid ejection heads 1 by connection flow paths 2135.

Pump 2134 is a liquid delivery pump, for example, a piezoelectric pump. Pump 2134 is connected to control unit 2118 and is driven and controlled by control unit 2118.

The connection flow path 2135 has a supply flow path that is connected to the ink supply pipe 123 of the liquid ejection head 1. The connection flow path 2135 also has a recovery flow path that is connected to the ink discharge pipe 124 of the liquid ejection head 1. For example, if the liquid ejection head 1 is a non-circulation type, the recovery circuit is connected to the maintenance device 2117, and if the liquid ejection head 1 is a circulation type, the recovery flow path is connected to the supply tank 2132.

The transport device 2115 transports paper P along a transport path 2001 that runs from the paper feed cassette 21121 of the medium supply unit 2112 through the image forming unit 2113 to the paper output tray 21141 of the medium output unit 2114. The transport device 2115 includes multiple guide plate pairs 21211-21218 and multiple transport rollers 21221-21228 arranged along the transport path 2001. The transport device 2115 supports the paper P so that it can move relative to the liquid ejection head 1.

The temperature adjustment device 2116 includes a temperature adjustment water tank 21161, a temperature adjustment circuit 21162 such as piping or tubes for supplying the temperature adjustment water, a pump for supplying the temperature adjustment water, and a temperature adjustment device for adjusting the temperature of the temperature adjustment water. The temperature adjustment device 2116 supplies the temperature adjustment water from the temperature adjustment water tank 21161, adjusted to a predetermined temperature by the temperature adjustment device, to the temperature adjustment water supply pipe 125 of the liquid ejection head 1 via the temperature adjustment circuit 21162 by pumping water. The temperature adjustment device 2116 also recovers water discharged from the temperature adjustment water discharge pipe through the manifold unit 12 back into the temperature adjustment water tank 21161 via the temperature adjustment circuit 21162. The temperature adjustment device 2116 may be, for example, a heater or cooler. The temperature adjustment device 2116 may also be configured to adjust the temperature of the ink supplied to the liquid ejection head 1.

The maintenance device 2117, for example, sucks and recovers ink remaining on the outer surface of the nozzle plate 114 during maintenance. Furthermore, if the liquid ejection head 1 is a non-circulating type, the maintenance device 2117 recovers ink from inside the head body 11 during maintenance. Such a maintenance device 2117 has a tray, tank, or the like for storing the recovered ink.

The control unit 2118 includes a CPU 21181 as an example of a processor, memory such as a ROM (Read Only Memory) that stores various programs, and a RAM (Random Access Memory) that temporarily stores various variable data and image data, and an interface unit that inputs and outputs data from the outside.

With the liquid ejection head 1 and liquid ejection device 2 configured in this manner, the resistance value of the electrode 117 can be reduced by providing an electrolytic Ni plating film 11733 on the electroless Ni plating film 11732.

Note that embodiments of the present invention are not limited to the configurations described above. For example, in the above example, the liquid ejection head 1 is described as having a pair of head bodies 11, but this is not limited to this and may also be configured as having a single head body 11. Also, in the above example, the liquid ejection head 1 is described as being of a non-circulating type, but it may also be of a circulating type.

In addition, in the above example, a configuration was described in which the first electrode portion 1171 of the electrode 117 is provided on each of the multiple individual electrodes 118 and the common electrode 119, but this is not limited to this. For example, the liquid ejection head 1 may be configured such that the common electrode 119 is formed by the first electrode portion 1171 and the second electrode portion 1172, and the multiple individual electrodes 118 are formed by the second electrode portion 1172.

In the above example, the first electrolytic metal plating film 11733 of the first electrode portion 1171 is an electrolytic Ni plating film, and the second electrolytic metal plating film 11734 is an electrolytic Au plating film, but this is not limited to this. In other words, the metal material of the first electrolytic metal plating film 11733 is not limited as long as it can be formed on the electroless Ni plating film 11732 by electrolytic plating and has lower electrical resistance than the electroless Ni plating film 11732. Similarly, the metal material of the second electrolytic metal plating film 11734 is not limited as long as it can be formed on the first electrolytic metal plating film 11733 by electrolytic plating and is a different metal from the first electrolytic metal plating film 11733.

According to at least one of the embodiments described above, the resistance value of the electrode can be reduced by providing a first electrolytic metal plating film and a second electrolytic metal plating film on the electroless Ni plating film.

While several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in a variety of other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

1...Liquid ejection head (inkjet head), 2...Liquid ejection device (inkjet recording device), 11...Head main body, 12...Manifold unit, 13...Circuit board, 14...Cover, 111...Substrate, 112...Frame member, 113...Actuator, 114...Nozzle plate, 116...Common liquid chamber, 117...Electrode, 118...Individual electrode, 119...Common electrode, 121...Manifold, 122...Top plate, 123...Ink supply pipe, 124...Ink discharge pipe, 125...Temperature-controlled water supply pipe, 131...Wiring film, 132...Driver IC, 133...Printed wiring Substrate, 141... outer shell, 142... mask plate, 1111... supply port, 1112... discharge port, 1116... connection portion, 1131... pressure chamber, 1132... air chamber, 1133... piezoelectric body (driving element), 1134... inclined surface, 1135... liquid-proof wall, 1141... nozzle, 1142... nozzle array, 1161... first common liquid chamber, 1162... second common liquid chamber, 1163... third common liquid chamber, 1171... first electrode portion, 1172... second electrode portion, 1211... supply flow path, 1213... temperature adjustment flow path, 2001... transport path, 2111... housing, 2112... medium supply portion, 2113... image forming portion, 21 14...medium discharge unit, 2115...transport device, 2116...temperature control device, 2117...maintenance device, 2118...control unit, 2120...support unit, 2130...head unit, 2132...supply tank, 2134...pump, 2135...connection flow path, 11731...Ni sputtered film, 11732...electroless Ni plating film, 11733...electrolytic Ni plating film (first electrolytic metal plating film), 11734...electrolytic Au plating film (second electrolytic metal plating film), 21121...paper feed cassette, 21141...paper output tray, 21201...transport belt, 21202...support plate, 21 203...belt roller, 21211...guide plate pair, 21212...guide plate pair, 21213...guide plate pair, 21214...guide plate pair, 21215...guide plate pair, 21216...guide plate pair, 21217...guide plate pair, 21218...guide plate pair, 21221...conveying roller, 21222...conveying roller, 21223...conveying roller, 21224...conveying roller, 21225...conveying roller, 21226...conveying roller, 21227...conveying roller, 21228...conveying roller, P...paper.

Claims (5)

an actuator having a plurality of pressure chambers arranged in one direction;
a substrate on which the actuator is provided;
an electrode for driving the pressure chamber, the electrode being formed on the substrate and the actuator, the conductor portion formed on the substrate being formed of a multilayer film including a Ni sputtered film, an electroless Ni plated film, a first electrolytic metal plated film, and a second electrolytic metal plated film of a metal different from the first electrolytic metal plated film, and the conductor portion formed on the actuator being formed of the Ni sputtered film and the electroless Ni plated film;
A liquid ejection head comprising: A liquid ejection head as described in claim 1, wherein the electrode is a common electrode that drives the multiple pressure chambers. A liquid ejection head as described in claim 1, wherein the electrodes include a common electrode that drives the multiple pressure chambers and multiple individual electrodes that drive each of the multiple pressure chambers. the first electrolytic metal plating film is an electrolytic Ni plating film,
4. The liquid ejection head according to claim 1, wherein the second electrolytic metal plating film is an electrolytic Au plating film. the actuator has a plurality of air chambers adjacent to the pressure chambers and arranged alternately with the pressure chambers;
The actuator is provided in pair,
5. The liquid ejection head according to claim 1, wherein the substrate is formed with a slot extending along the longitudinal direction of the actuators between the pair of actuators.