JP4639957B2 - Droplet discharge head and droplet discharge apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head and a droplet discharge device that discharge ink droplets and the like.

  Conventionally, ink droplets are selectively ejected from a plurality of nozzles of an ink jet recording head that reciprocates in the main scanning direction (hereinafter simply referred to as “recording head”) or an ink jet recording head having a paper width, and the sub scanning direction 2. Description of the Related Art An ink jet recording apparatus that prints characters, images, and the like on a recording medium such as recording paper that is conveyed to a printer is known.

  In the ink jet recording head having such a configuration, it is desired to realize a high resolution of 1200 dpi and further 2400 dpi as a next generation ink jet head. In order to obtain a piezo-type ink jet head with high resolution, a plurality of nozzle arrays are required. Also, the wiring to the piezoelectric element (PZT element or the like) is an individual wiring, is routed from each piezoelectric element, and is connected to the driving IC.

  For example, in Patent Document 1, piezoelectric elements are stacked, and through holes are provided in the stacked piezoelectric elements, and the through holes are filled with a conductive material, and the internal common electrode or the other one of the polarities of the piezoelectric elements is filled. The conductive layers that make up the internal individual electrodes of the polarity of each other are interconnected by through-holes, and a flexible cable that can be connected to the internal common electrode or the internal individual electrode is connected to the end face of the piezoelectric element, and voltage is applied to the piezoelectric element. Can be applied.

  However, with such a configuration, the piezoelectric element itself is a complicated configuration, which increases the cost. In addition, since the connection area between the end face of the piezoelectric element and the flexible cable is wide, it is difficult to obtain a high-density matrix arrangement. In addition, when a flexible cable is connected to the end face of the piezoelectric element, it affects the vibration of the piezoelectric body.

For this reason, as shown in FIG. 10, an upper electrode 200 (corresponding to an internal individual electrode) is disposed on the upper surface of the piezoelectric body 204, and a lower electrode 202 (corresponding to an internal common electrode) is disposed on the lower surface of the piezoelectric body 204. Although the element 210 is constituted, the piezoelectric body constituting the piezoelectric element is intended to have a thickness of about 5 to 20 μm, and between the upper surface of the upper electrode 200 and the upper surface of the lower electrode 202 in a normal LSI process. Therefore, a height difference corresponding to the thickness of the piezoelectric body 204 is generated. Here, when the metal wiring 206 is routed, a local reduction in the wiring width (thinning) occurs due to the height difference of the thickness of the piezoelectric body 204. And when remarkable, the disconnection of the metal wiring 206 may arise.
JP 2000-94679 A

  In consideration of the above-described facts, an object of the present invention is to provide a droplet discharge head and a droplet discharge device that prevent disconnection of metal wiring that connects a piezoelectric body and a drive IC.

In order to achieve the above object, according to a first aspect of the present invention, in the droplet discharge head, a nozzle that discharges a droplet, a pressure chamber that communicates with the nozzle and is filled with the droplet, and the pressure A diaphragm constituting a part of the chamber, a droplet pool chamber for pooling droplets supplied to the pressure chamber via a droplet flow path, a piezoelectric body capable of displacing the diaphragm, and the diaphragm And a lower electrode having one polarity of the piezoelectric body, an upper electrode provided on the upper surface of the piezoelectric body and having the other polarity, and the upper electrode and the lower electrode. A drive IC for applying a voltage, and an electrode part formed on the same surface of the diaphragm with a gap between the lower electrode and connected to the drive IC; and from the electrode part to the upper part a through hole formed in the piezoelectric body formed over the electrode, the transmural Filled into the hole, and having a conductor for conducting the one upper electrode and the electrode portion.

In the first aspect of the present invention, the electrode portion connected to the drive IC is formed on the diaphragm in a state of being insulated from the lower electrode. A through hole is provided in the piezoelectric body formed from the electrode portion to the upper electrode, and a conductor is buried in the through hole so that the electrode portion and the upper electrode are electrically connected.

  As a result, the upper electrode is connected to the driving IC through the conductor and the electrode portion, and it is not necessary to route the metal wiring from the upper surface of the upper electrode. For this reason, problems such as disconnection of the metal wiring caused by routing the metal wiring do not occur. In addition, since the resin that covers the surface of the metal wiring is not required to prevent the corrosion of the metal wiring, the vibration characteristics of the piezoelectric body are stabilized.

  In addition, by forming a through hole in the piezoelectric body, burying a conductor in the through hole, and conducting the electrode part located on the opposite side of the upper electrode and the upper electrode, a simple wiring structure can be obtained and the cost can be reduced. Is realized and high reliability is obtained.

Further, by forming a gap between the lower electrode and the electrode portion on the same surface of the diaphragm , a so-called common electrode (corresponding to the lower electrode) and address electrode (corresponding to the upper electrode) can be formed on the same process. Can be formed. Thereby, a man-hour can be reduced and cost reduction can be realized.

Further, for example, compared with a method of connecting to the upper electrode from the upper surface of the upper electrode by FFC (Flexible Flat Cable), the connection region of the upper electrode can be narrowed, and a high-density matrix arrangement can be obtained. In addition, the influence of vibration on the piezoelectric body due to the connection state of the FFC is eliminated, and a stable liquid droplet ejection head without variation is obtained. The invention according to claim 2, in the liquid droplet ejection head according to claim 1, The electrode portion is formed when the lower electrode is formed.

  According to the second aspect of the present invention, the number of steps can be reduced and the cost can be reduced by forming the electrode portion when forming the lower electrode.

  According to a third aspect of the present invention, in the liquid droplet ejection head according to the first or second aspect, the conductor is buried in the through hole by a plating method or a plasma method.

  According to a fourth aspect of the present invention, in the droplet discharge device, any one of the first to third aspects includes a droplet discharge head.

Since the present invention has the above configuration, the upper electrode is connected to the driving IC through the conductor and the electrode portion, and it is not necessary to route the metal wiring from the upper surface of the upper electrode. For this reason, problems such as disconnection of the metal wiring caused by routing the metal wiring do not occur. In addition, since the resin that covers the surface of the metal wiring is not required to prevent the corrosion of the metal wiring, the vibration characteristics of the piezoelectric body are stabilized. In addition, by forming a through hole in the piezoelectric body, burying a conductor in the through hole, and conducting the electrode part located on the opposite side of the upper electrode and the upper electrode, a simple wiring structure can be obtained and the cost can be reduced. Is realized and high reliability is obtained. Furthermore, a gap is provided between the diaphragm and the lower surface of the piezoelectric body, and an electrode portion is formed on the same surface of the diaphragm so that a so-called common electrode (corresponding to the lower electrode) and address electrode are formed. (Corresponding to the upper electrode) can be formed in the same process. Thereby, a man-hour can be reduced and cost reduction can be realized. Further, for example, compared with a method of connecting to the upper electrode from the upper surface of the upper electrode by FFC (Flexible Flat Cable), the connection region of the upper electrode can be narrowed, and a high-density matrix arrangement can be obtained. In addition, the influence of vibration on the piezoelectric body due to the connection state of the FFC is eliminated, and a stable droplet discharge head without variations can be obtained.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on examples shown in the drawings. The recording medium will be described as recording paper P. In addition, the conveyance direction of the recording paper P in the inkjet recording apparatus 10 is represented by an arrow S as a sub-scanning direction, and a direction orthogonal to the conveyance direction is represented by an arrow M as a main scanning direction. Further, in the figure, when an arrow UP and an arrow LO are shown, it indicates an upward direction and a downward direction, respectively, and when expressed in an up and down direction, it corresponds to each of the arrows.

  First, an outline of the ink jet recording apparatus 10 will be described. As shown in FIG. 1, the inkjet recording apparatus 10 includes a carriage 12 on which black, yellow, magenta, and cyan inkjet recording units 30 (inkjet recording heads 32) are mounted. A pair of brackets 14 project from the carriage 12 on the upstream side in the conveyance direction of the recording paper P, and the bracket 14 has a circular opening 14A (see FIG. 2). A shaft 20 installed in the main scanning direction is inserted through the opening 14A.

  Further, a drive pulley (not shown) and a driven pulley (not shown) constituting the main scanning mechanism 16 are disposed at both ends in the main scanning direction, and wound around the driving pulley and the driven pulley, A part of the timing belt 22 that travels in the main scanning direction is fixed to the carriage 12. Therefore, the carriage 12 is supported so as to be reciprocally movable in the main scanning direction.

  Further, the ink jet recording apparatus 10 is provided with a paper feed tray 26 in which the recording paper P before image printing is bundled and placed above the paper feed tray 26 by an ink jet recording head 32. A paper discharge tray 28 for discharging the recording paper P printed with is provided. A sub-scanning mechanism 18 including a transport roller and a discharge roller for transporting the recording paper P fed one by one from the paper feed tray 26 in the sub-scanning direction at a predetermined pitch is provided.

  In addition, the inkjet recording apparatus 10 is provided with a control panel 24 for performing various settings during printing, a maintenance station (not shown), and the like. The maintenance station includes a cap member, a suction pump, a dummy jet receiver, a cleaning mechanism, and the like, and performs maintenance operations such as a suction recovery operation, a dummy jet operation, and a cleaning operation.

  In addition, as shown in FIG. 2, each color ink jet recording unit 30 includes an ink jet recording head 32 and an ink tank 34 that supplies ink to the ink jet recording unit 32. A plurality of nozzles 56 (see FIG. 3) formed on the ink ejection surface 32A are mounted on the carriage 12 so as to face the recording paper P. Accordingly, by selectively ejecting ink droplets from the nozzles 56 to the recording paper P while the inkjet recording head 32 is moved in the main scanning direction by the main scanning mechanism 16, image data is converted into image data for a predetermined band region. A portion of the based image is recorded.

  When one movement in the main scanning direction is completed, the recording paper P is conveyed by a predetermined pitch in the sub scanning direction by the sub scanning mechanism 18, and the ink jet recording head 32 (ink jet recording unit 30) is again moved in the main scanning direction ( A part of the image based on the image data is recorded in the next band area while moving in the opposite direction). By repeating such an operation a plurality of times, the recording paper P The entire image based on the image data is recorded in full color.

  Next, the inkjet recording head 32 in the inkjet recording apparatus 10 configured as described above will be described in detail.

  FIG. 3 is a schematic plan view showing the configuration of the inkjet recording head 32, and FIG. 4 is a schematic cross-sectional view taken along the line XX of FIG. As shown in FIGS. 3 and 4, the ink jet recording head 32 is provided with an ink supply port 36 communicating with the ink tank 34. The ink 110 injected from the ink supply port 36 is supplied to the ink pool chamber. 38 is stored.

  The volume of the ink pool chamber 38 is defined by the top plate 40 and the partition wall 42, and a plurality of ink supply ports 36 are formed in predetermined positions on the top plate 40 in rows. The top plate 40 may be made of any material such as glass, ceramics, silicon, resin, etc., as long as it is an insulator having a strength that can serve as a support for the inkjet recording head 32. Further, the top plate 40 is provided with a metal wiring 90 for energizing a drive IC 60 described later. The metal wiring 90 is covered and protected by a resin film 92 so that erosion by the ink 110 is prevented.

  The partition wall 42 is formed of resin (photosensitive dry film) and partitions the ink pool chamber 38 into a rectangular shape. The ink pool chamber 38 is separated vertically from the pressure chamber 50 via a piezoelectric element 46 and a diaphragm 48 that is bent and deformed in the vertical direction by the piezoelectric element 46. That is, the piezoelectric element 46 and the diaphragm 48 are arranged between the ink pool chamber 38 and the pressure chamber 50, and the ink pool chamber 38 and the pressure chamber 50 are configured not to exist on the same horizontal plane. ing.

  Therefore, the pressure chambers 50 can be arranged close to each other, and the nozzles 56 can be arranged in a matrix at high density. In addition, with such a configuration, an image can be formed in a wide band area by one movement of the carriage 12 in the main scanning direction, so that the scanning time can be shortened. That is, it is possible to realize high-speed printing in which image formation is performed over the entire surface of the recording paper P with a small number of movements and time of the carriage 12.

  Here, the diaphragm 48 is formed of a metal such as SUS, has elasticity in at least the vertical direction, and is configured to bend and deform (displace) in the vertical direction when a voltage is applied to the piezoelectric element 46. Yes. The diaphragm 48 may be an insulating material such as glass.

  On the other hand, the piezoelectric elements 46 are arranged in a matrix (see FIG. 3), are provided on the upper portion of the diaphragm 48 for each pressure chamber 50, and are constituted by a piezoelectric body 94 formed of a PZT film. A lower electrode 52 having one polarity is provided between the lower surface of the piezoelectric body 94 and the diaphragm 48, and an upper electrode 54 having the other polarity is provided on the upper surface of the piezoelectric body 94.

  In addition, on the same plane of the lower electrode 52, an electrode portion 120 is formed in a state where a gap is provided between the lower electrode 52 and connected to the driving IC 60. A part of the electrode portion 120 is provided on the lower surface of the piezoelectric body 94 and faces the upper electrode 54 with the piezoelectric body 94 interposed therebetween.

  A through hole 124 is formed in the piezoelectric body 94 from the electrode portion 120 to the upper electrode 54. A conductor 126 is embedded in the through hole 124 by a plating method or a plasma method. 54 can be conducted through the conductor 126.

  The piezoelectric element 46 is covered and protected by a low water permeable insulating film (SiOx film) 80. Since the low water-permeable insulating film (SiOx film) 80 is deposited on the piezoelectric element 46 under the condition that the moisture permeability is low, moisture penetrates into the piezoelectric element 46 and becomes unreliable (so-called PZT). Deterioration of piezoelectric characteristics caused by reducing oxygen in the film can be prevented. The diaphragm 48 made of metal (SUS or the like) that contacts the lower electrode 52 functions also as a low resistance GND wiring.

  Further, the upper surface of the low water permeable insulating film (SiOx film) 80 is covered and protected by a resin protective film 88 to prevent erosion by the ink 110, but above the piezoelectric element 46 is a resin protective film. 88 is configured not to be covered. Since the resin film 82 is a flexible resin layer, this configuration prevents the displacement of the piezoelectric element 46 (the diaphragm 48) from being prevented (preferably bendable and deformable in the vertical direction). ). That is, since the resin layer above the piezoelectric element 46 is thinner, the effect of suppressing displacement inhibition is higher, so that the resin protective film 88 is not covered.

  An isolation chamber 112 is provided above the piezoelectric element 46, and the isolation chamber 112 isolates the piezoelectric element 46 from the ink 110. Thereby, since the restraining force by the ink 110 is not applied to the piezoelectric element 46, the bending deformation of the piezoelectric element 46 is not hindered by the restraining force. Further, by isolating the piezoelectric element 46 from the ink 110 by the isolation chamber 112, the piezoelectric element 46 is protected from ink erosion.

  When the pressure chamber 50 is pressurized by the bending deformation of the piezoelectric element 46 and the ink 110 is ejected as an ink droplet from the nozzle 56 communicating with the pressure chamber 50, the ink 110 is transmitted into the ink pool chamber 38 via the ink channel 66. The pressure wave of the ink 110 is alleviated by the air damper 44 provided in the isolation chamber 112.

  On the other hand, the drive IC 60 is disposed outside the ink pool chamber 38 defined by the partition wall 42 and between the top plate 40 and the diaphragm 48 and is not exposed from the diaphragm 48 or the top plate 40. ing. Therefore, it is possible to reduce the size of the inkjet recording head 32.

  The periphery of the drive IC 60 is sealed with a resin material 58. As shown in FIG. 5, a plurality of injection ports 40B for the resin material 58 for sealing the drive IC 60 are formed in a lattice shape so as to partition each inkjet recording head 32 in the top plate 40 in the manufacturing stage. After the piezoelectric element substrate 70 and the flow path substrate 72 formed with the pressure chamber 50 are joined (joined), the top plate 40 is cut along the injection port 40B sealed (closed) by the resin material 58. As a result, a plurality of inkjet recording heads 32 having matrix-like nozzles 56 (see FIG. 3) are manufactured at a time.

  Further, as shown in FIGS. 4 and 6, a plurality of bumps 62 protrude in a matrix shape at a predetermined height on the lower surface of the drive IC 60, and the piezoelectric element 46 is formed on the vibration plate 48. The chip substrate is flip-chip mounted. Therefore, high-density connection to the piezoelectric element 46 can be easily realized, and the height of the drive IC 60 can be reduced (thinner can be reduced). This also makes it possible to reduce the size of the inkjet recording head 32.

  In FIG. 4, bumps 64 are provided outside the driving IC 60. The bumps 64 connect the metal wiring 90 provided on the top plate 40 and the electrode portions 120 provided on the piezoelectric element substrate 70, and of course, are higher than the height of the drive IC 60 mounted on the piezoelectric element substrate 70. It is provided to be higher.

  Accordingly, the metal wiring 90 of the top plate 40 is energized from the main body side of the ink jet recording apparatus 10, the electrode portion 120 is energized from the metal wiring 90 of the top plate 40 via the bumps 64, and then the drive IC 60 is energized. It is. The drive IC 60 applies a voltage to the piezoelectric element 46 at a predetermined timing, and the diaphragm 48 bends and deforms in the vertical direction, so that the ink 110 filled in the pressure chamber 50 is pressurized, and the nozzle In this configuration, ink droplets are ejected from 56.

  One nozzle 56 for ejecting ink droplets is provided at a predetermined position for each pressure chamber 50. The pressure chamber 50 and the ink pool chamber 38 avoid the piezoelectric element 46 and extend from the pressure chamber 50 in the horizontal direction through the ink flow path 66 passing through the through hole 48A formed in the vibration plate 48. The ink flow path 68 is connected by communication. The ink flow path 68 is slightly smaller than the connection portion with the actual ink flow path 66 in advance so that alignment with the ink flow path 66 can be performed at the time of manufacturing the ink jet recording head 32 (so as to ensure communication). It is provided longer.

  Next, the operation of the inkjet recording apparatus 10 including the inkjet recording head 32 will be described.

  First, when an electrical signal for instructing printing is sent to the ink jet recording apparatus 10 shown in FIGS. 1 and 2, one sheet of recording paper P is picked up from the paper feed tray 26 and conveyed to a predetermined position by the sub-scanning mechanism 18. Is done.

  On the other hand, in the inkjet recording unit 30, the ink 110 has already been injected (filled) from the ink tank 34 into the ink pool chamber 38 of the inkjet recording head 32 via the ink supply port 36 shown in FIG. The ink 110 is supplied (filled) to the pressure chamber 50 through the ink flow paths 66 and 68. At this time, a meniscus in which the surface of the ink 110 is slightly recessed toward the pressure chamber 50 is formed at the tip (ejection port) of the nozzle 56.

  The ink jet recording head 32 mounted on the carriage 12 selectively ejects ink droplets from the plurality of nozzles 56 while moving in the main scanning direction, so that the image data is transferred to a predetermined band area of the recording paper P. Record part of the image based on.

  That is, a voltage is applied to a predetermined piezoelectric element 46 at a predetermined timing by the drive IC 60, and the vibration plate 48 is bent and deformed in the vertical direction (vibrated out of plane) to apply the ink 110 in the pressure chamber 50. And ejected as ink droplets from a predetermined nozzle 56.

  When a part of the image based on the image data is recorded on the recording paper P in this way, the recording paper P is conveyed by a predetermined pitch by the sub-scanning mechanism 18, and the ink jet recording head 32 is moved in the main scanning direction as described above. However, a part of the image based on the image data is recorded in the next band area of the recording paper P by selectively ejecting ink droplets selectively from the plurality of nozzles 56 again.

  Such an operation is repeated, and when the image based on the image data is completely recorded on the recording paper P, the sub-scanning mechanism 18 transports the recording paper P to the end, and the recording paper P is placed on the paper discharge tray 28. Is discharged. Thereby, the printing process (image recording) on the recording paper P is completed.

  Next, the gist of the ink jet recording head according to the embodiment of the present invention will be described.

  As shown in FIG. 4, in this embodiment, an electrode portion 120 that is insulated from the lower electrode 52 and connected to the drive IC 60 is formed on the diaphragm 48. A through hole 124 is formed from the electrode portion 120 to the upper electrode 54, and a conductor 126 is buried in the through hole 124 so that the electrode portion 120 and the upper electrode 54 are electrically connected.

  As a result, the upper electrode 54 is connected to the drive IC 60 through the conductor 126 and the electrode portion 120, and it is not necessary to route the metal wiring 206 (see FIG. 10) from the upper surface of the upper electrode 54 as in the conventional case. For this reason, problems such as disconnection of the metal wiring 206 caused by routing the metal wiring 206 do not occur. In addition, since the resin that covers the surface of the metal wiring 206 is not required to prevent the corrosion of the metal wiring 206, the vibration characteristics of the piezoelectric body 94 are stabilized.

  On the other hand, a through-hole 124 is formed in the piezoelectric body 94, a conductor 126 is buried in the through-hole 124, and the upper electrode 54 and the electrode portion 120 located on the opposite side of the upper electrode 54 are made conductive, thereby providing a simple wiring structure. As a result, the cost can be reduced and high reliability can be obtained.

  Further, for example, compared with a method of connecting to the upper electrode 54 from the upper surface of the upper electrode 54 by FFC (Flexible Flat Cable), the connection region of the upper electrode 54 can be narrowed, and a high-density matrix arrangement can be obtained. Further, the influence of vibration on the piezoelectric body 94 due to the connection state of the FFC is eliminated, and the stable ink jet recording head 32 without variation is obtained.

  Next, a method of forming the piezoelectric element 46 in the ink jet recording head 32 having the above configuration will be described.

  First, FIG. 8 (A) and FIG. 9 (A) (Note that FIG. 9 (A) is a cross-sectional view taken along the line AA in FIG. 8 (A), and FIG. As described above, the lower electrode 52 and the electrode unit 120 are patterned on the upper surface of the diaphragm 48. Specifically, metal film sputtering, resist formation by photolithography, patterning (etching), and resist removal by oxygen plasma are performed, but the electrode portion 120 has a gap (groove portion 121) provided between the lower electrode 52 and the electrode portion 120. Formed with. The lower electrode 52 becomes the ground potential.

  Next, as shown in FIG. 8B and FIG. 9B, a low water permeable insulating film (SiOx film) 80 is laminated on the upper surfaces of the lower electrode 52 and the electrode part 120. Excluding the region where the groove is formed (groove 123).

  Then, as shown in FIGS. 8C and 9C, the material of the piezoelectric element 46 is formed on the upper surface of the exposed lower electrode 52 and electrode portion 120 and the low water-permeable insulating film (SiOx film) 80. After a certain PZT film (hereinafter referred to as “piezoelectric body 94”) is laminated by sputtering, an upper electrode 54 is laminated on the upper surface of the piezoelectric body 94 by sputtering as shown in FIG. 8D.

  Then, as shown in FIG. 8E, a resist mask 122 is formed on the upper surface of the upper electrode 54 in order to pattern the piezoelectric body 94 and the upper electrode 54. Here, examples of the electrode material of the lower electrode 52 and the upper electrode 54 include Au, Ir, Ru, and Pt that have high affinity with a PZT material that is a piezoelectric body and have heat resistance.

  Next, as shown in FIGS. 8F and 9D, the upper electrode 54 and the piezoelectric body 94 are patterned by dry etching. Thereby, a through hole 124 penetrating the upper electrode 54 and the piezoelectric body 94 is formed. Then, as shown in FIGS. 8G and 9E, after the conductor 126 is embedded in the through hole 124 by a plating method or a plasma method, a resist is formed as shown in FIG. The mask 122 is removed, and the piezoelectric element 46 is formed.

  As described above, in this embodiment, the electrode portion 120 is formed on the upper surface of the diaphragm 48 on the same plane as the lower electrode 52, so that a so-called common electrode (corresponding to the lower electrode 52) and address electrode (upper electrode 54). Can be formed on the same process. Thereby, a man-hour can be reduced and cost reduction can be realized.

  In the ink jet recording apparatus 10 of the above embodiment, black, yellow, magenta, and cyan ink jet recording units 30 are mounted on the carriage 12 and selectively selected from the ink jet recording heads 32 of the respective colors based on image data. Although ink droplets are ejected and a full-color image is recorded on the recording paper P, ink jet recording in the present invention is not limited to recording characters and images on the recording paper P.

  That is, the recording medium is not limited to paper, and the liquid to be ejected is not limited to ink. For example, industrially used liquids such as creating color filters for displays by discharging ink onto polymer films or glass, or forming bumps for component mounting by discharging welded solder onto a substrate The ink jet recording head 32 according to the present invention can be applied to all droplet ejecting apparatuses.

  In the inkjet recording apparatus 10 of the above embodiment, the example of the partial width array (PWA) having the main scanning mechanism 16 and the sub-scanning mechanism 18 has been described. However, the inkjet recording in the present invention is not limited to this, and the paper width A corresponding so-called Full Width Array (FWA) may be used. Rather, since the present invention is effective for realizing a high-density nozzle arrangement, it is suitable for FWA that requires one-pass printing.

1 is a schematic perspective view showing an ink jet recording apparatus according to an embodiment of the present invention. 1 is a schematic perspective view showing an ink jet recording unit mounted on a carriage according to an embodiment of the present invention. 1 is a schematic plan view illustrating a configuration of an ink jet recording head according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view taken along the line XX of FIG. 3 and shows an ink jet recording head according to an embodiment of the present invention. It is a schematic plan view which shows the top plate before cut | disconnecting as an inkjet recording head which concerns on embodiment of this invention. FIG. 3 is a schematic plan view showing bumps of a driving IC provided in the ink jet recording head according to the embodiment of the present invention. 1 is a schematic perspective view showing a configuration and a board of an ink jet recording head according to an embodiment of the present invention. (A)-(D) are schematic sectional drawings which show the process of forming the piezoelectric element of the inkjet recording head which concerns on embodiment of this invention. (E)-(H) are schematic sectional drawings which show the process of forming the piezoelectric element of the inkjet recording head which concerns on embodiment of this invention. (A)-(C) are schematic plan views which show the process of forming the piezoelectric element of the inkjet recording head which concerns on embodiment of this invention. (D)-(E) are schematic plan views which show the process of forming the piezoelectric element of the inkjet recording head which concerns on embodiment of this invention. Schematic sectional view showing the structure of a conventional inkjet recording head

Explanation of symbols

10 Inkjet recording device (droplet ejection device)
32 Inkjet recording head (droplet ejection head)
38 Ink pool chamber (droplet pool chamber)
46 Piezoelectric element 48 Diaphragm 50 Pressure chamber 52 Lower electrode 54 Upper electrode 56 Nozzle 94 Piezoelectric body 120 Electrode portion 124 Through hole 126 Conductor

Claims (4)

A nozzle for discharging droplets;
A pressure chamber in communication with the nozzle and filled with droplets;
A diaphragm constituting a part of the pressure chamber;
A droplet pool chamber for pooling droplets to be supplied to the pressure chamber via a droplet channel;
A piezoelectric body capable of displacing the diaphragm;
A lower electrode formed between the diaphragm and the lower surface of the piezoelectric body and having one polarity of the piezoelectric body;
An upper electrode provided on the upper surface of the piezoelectric body and having the other polarity;
A driving IC for applying a voltage to the upper electrode and the lower electrode;
With
An electrode part formed on the same surface of the diaphragm with a gap between the lower electrode and connected to the driving IC;
A through hole provided in the piezoelectric body formed from the electrode portion to the upper electrode;
A conductor buried in the through-hole and conducting the electrode part and the upper electrode;
A droplet discharge head characterized by comprising:   The droplet discharge head according to claim 1, wherein the electrode portion is formed when the lower electrode is formed.   The droplet discharge head according to claim 1, wherein the conductor is buried in the through hole by a plating method or a plasma method.   A liquid droplet ejection apparatus comprising the liquid droplet ejection head according to claim 1.

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