JP2006281777A - Liquid droplet ejection head and liquid droplet ejection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inkjet recording head which can increase the density of nozzles, increase resolution by realizing formation of fine-pitch wiring along with the density increase, and reduce the size thereof. <P>SOLUTION: A piezoelectric substrate 50 composed of an oscillation plate 52 and a piezoelectric element 54 is interposed between a fluid channel substrate 80 in the lower side and a first upper substrate 70 in the upper side. The piezoelectric element 54 is electrically connected to the first upper substrate 70 by a bump 78. A drive IC 77 which drives the piezoelectric element 54 is mounted on the first upper substrate 70. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nozzle that discharges droplets, a pressure chamber that communicates with the nozzle and is filled with a fluid, a diaphragm that forms part of the pressure chamber, and a fluid that is supplied to the pressure chamber via a fluid channel The present invention relates to a liquid droplet ejection head having a fluid pool chamber for pooling a liquid crystal and a piezoelectric element for displacing a vibration plate, and a liquid droplet ejection apparatus including the liquid droplet ejection head.

  Conventionally, as a liquid droplet ejection head, ink droplets are selectively ejected from a plurality of nozzles of an ink jet recording head (hereinafter sometimes simply referred to as “recording head”), and characters, images, etc. are recorded on a recording medium such as recording paper. Inkjet recording apparatuses for printing are known.

  By the way, in the ink jet recording apparatus, the recording head includes a piezoelectric method and a thermal method. For example, in the case of the piezoelectric method, as shown in FIGS. 25 and 26, a piezoelectric element (actuator that converts electrical energy into mechanical energy) is supplied to a pressure chamber 204 to which ink is supplied from an ink tank through an ink pool chamber 202. 206 is provided, and the piezoelectric element 206 is bent and deformed in a concave shape so as to reduce the volume of the pressure chamber 204, pressurizes the ink therein, and ejects the ink droplet 200A from the nozzle 208 communicating with the pressure chamber 204. It is configured.

  In recent years, the inkjet recording head having such a configuration is required to be capable of high-resolution printing while being low-cost and small. In order to meet this requirement, it is necessary to arrange the nozzles at a high density. However, in the current recording head, as shown in the drawing, the ink is adjacent to the nozzle 208 (between the nozzle 208 and the nozzle 208). Since the pool chamber 202 is provided, there is a limit to disposing the nozzles 208 at high density.

  The ink jet recording head is provided with a drive IC for applying a voltage to a predetermined piezoelectric element. Conventionally, the ink jet recording head is mounted with an FPC (flexible printed circuit board) 210 as shown in FIG. That is, the bumps 212 formed on the FPC 210 are joined to the metal electrode surface on the upper surface of the piezoelectric element 206 provided on the vibration plate 214. Since the FPC 210 is mounted with a driving IC (not shown), the piezoelectric element 206 and the driving IC are electrically connected at this stage.

  In addition, there is a method in which an electrode terminal provided on the outer surface of the recording head is connected to an electrode terminal on a mounting substrate on which a driving IC is mounted by a wire bonding method (for example, see Patent Document 1). Further, there is a method in which a driving IC is joined and connected to an electrode terminal provided on the external surface of the recording head, and then an FPC is joined and connected to an electrode terminal of a lead wiring provided in the recording head (for example, , See Patent Document 2).

However, in any case, wiring with a fine pitch (for example, 10 μm pitch or less) cannot be formed. Therefore, when the nozzle density is increased, the size of the mounting substrate and the FPC is increased, and the miniaturization is inhibited. There is a problem of increasing costs. Further, when the nozzle density is increased, wiring having a desired resistance value cannot be routed, and there is a limit to increasing the nozzle density by limiting the wiring density.
JP-A-2-301445 JP-A-9-323414

  In view of such problems, the present invention makes it possible to achieve high resolution by realizing high-density nozzles and the formation of fine pitch wirings associated therewith, and droplets that can also be miniaturized. It is an object of the present invention to provide an ejection head and a droplet ejection apparatus provided with the droplet ejection head.

  In order to achieve the above object, a droplet discharge head according to claim 1 according to the present invention includes a nozzle that discharges a droplet, a pressure chamber that communicates with the nozzle and is filled with a fluid, and the pressure A piezoelectric element substrate including a diaphragm constituting a part of the chamber and a piezoelectric element for displacing the diaphragm, and provided on the opposite side of the pressure chamber with the piezoelectric element substrate interposed therebetween. A fluid pool chamber that pools fluid to be supplied to the pressure chamber; and is disposed between the fluid pool chamber and the piezoelectric element substrate so as to be spaced apart from the piezoelectric element substrate, and from the fluid pool chamber An upper substrate formed with a through-hole for supplying a fluid to the pressure chamber and a piezoelectric element substrate disposed between the piezoelectric element substrate and the piezoelectric element substrate are provided opposite to the pressure chamber so as to face each other. Formed on the upper substrate and the upper substrate A wiring connected to at least a driving means for driving the piezoelectric element, and a connecting member disposed between the opposing upper substrate and the piezoelectric element and electrically connecting the wiring and the piezoelectric element. Yes.

  In the first aspect of the present invention, since the fluid pool chamber is provided on the opposite side of the pressure chamber with the piezoelectric element substrate therebetween, the pressure chambers can be disposed close to each other, and The nozzles provided in the can be arranged with high density.

  Further, wiring for connecting the driving means and the piezoelectric element is provided on the upper substrate, and the opposing piezoelectric element and the wiring are electrically connected by a connecting member. Therefore, it is not necessary to get over the step on the substrate formed by the piezoelectric element as in the case where the wiring with the driving means is provided on the piezoelectric element substrate, and wiring becomes easy.

  In the droplet discharge head according to the present invention, since the upper substrate is disposed between the fluid pool chamber and the piezoelectric element substrate, the piezoelectric substrate can be easily fluidized without forming an isolation layer by the upper substrate. Can be isolated from. Further, by forming the through hole in the upper substrate, it is possible to easily supply the fluid to each pressure chamber.

  The droplet discharge head according to claim 2, wherein the wiring includes an opposing wiring formed on an opposing surface of the upper substrate on the side facing the piezoelectric element substrate. .

  By forming the opposing wiring on the opposing surface of the upper substrate as in the above configuration, the connection member can be easily connected with a simple configuration.

  The droplet discharge head according to claim 3, wherein the wiring has a through-wiring that penetrates the opposing surface and a back surface behind the opposing surface, and a back surface that is connected to the through-wiring and disposed on the back surface. It is characterized by including wiring.

  By forming the back surface wiring on the back surface of the upper substrate as in the above configuration, the area where the wiring can be formed increases and the degree of freedom of the wiring increases.

  The droplet discharge head according to claim 4 is characterized in that the driving means is mounted on a substrate different from the upper substrate.

  According to the above configuration, since the driving unit is not mounted on the upper substrate, the droplet discharge head can be reduced in size.

  The droplet discharge head according to claim 5 is characterized in that the driving means is mounted on the upper substrate.

  According to the above configuration, since the driving means that can be a heat source is arranged on the upper substrate, the temperature rise of the fluid in the pressure chamber can be suppressed as compared with the case where it is mounted on the piezoelectric element substrate.

  The droplet discharge head according to claim 6 is characterized in that the driving means is mounted on the back surface.

  According to the above configuration, since the driving means is not disposed between the upper substrate and the piezoelectric element substrate, it can be easily mounted even after the upper substrate and the piezoelectric element substrate are joined.

  The droplet discharge head according to claim 7 is characterized in that the driving means is disposed in the fluid pool chamber.

  By arranging the drive means that can be a heat source in the fluid pool chamber as in the above configuration, the drive means can be cooled by the fluid in the fluid pool chamber, and the influence on each substrate due to the heat generated by the drive means can be suppressed. Can do.

  The droplet discharge head according to claim 8 is characterized in that the driving means is mounted on the facing surface of the upper substrate.

  According to the above configuration, the driving unit can be mounted with a simple configuration. In addition, since it is not necessary to mount a device serving as a driving means such as an IC on the back surface (surface on the fluid pool chamber side) of the upper substrate, it is not necessary to provide a space for joining the partition walls of the fluid pool chamber, and droplet discharge The head can be reduced in size.

  The driving means of the droplet discharge head according to any one of claims 1 to 8 may be configured by an integrated circuit as described in claim 9 or may include a thin film transistor as described in claim 10. Can be.

  The droplet discharge head according to claim 11 is the droplet discharge head according to any one of claims 1 to 10, wherein one through hole is formed for one piezoelectric element. It is characterized by.

  According to the said structure, it can make it difficult to receive the influence of the vibration from another pressure chamber about each pressure chamber.

  The droplet discharge head according to claim 12 is the droplet discharge head according to any one of claims 1 to 11, wherein the droplet discharge head is provided between the upper substrate and the piezoelectric element substrate. A fluid supply path that communicates with a port and supplies fluid to the pressure chamber is formed, and a rib partition that forms a cavity between the upper substrate and the piezoelectric element substrate is further provided. .

  In the above configuration, the rib partition wall forms a cavity between the fluid supply path communicating with the through-hole and the upper substrate and the piezoelectric element substrate. Therefore, a fluid can be supplied to the pressure chamber with a simple configuration, and a cavity for preventing deformation of the diaphragm can be configured. In addition, the piezoelectric element can be easily isolated from the fluid.

  A droplet discharge head according to a thirteenth aspect is the droplet discharge head according to the twelfth aspect, characterized in that the cavity communicates with the atmosphere.

  According to the said structure, the fluctuation | variation of the air pressure in a cavity produced when the said cavity is sealed can be prevented.

  A droplet discharge head according to a fourteenth aspect is the droplet discharge head according to the first to thirteenth aspects, wherein the nozzles are arranged in a matrix.

  In this way, high resolution can be realized by arranging the nozzles in a matrix.

  A droplet discharge device according to a fifteenth aspect includes the droplet discharge head according to any one of the first to fourteenth aspects.

  According to the droplet discharge device of the present invention, since the nozzles of the droplet discharge head can be arranged with high density, a high-resolution image can be recorded. Further, since the droplet discharge head can be reduced in size, the droplet discharge device can also be reduced in size.

  As described above, according to the present invention, it is possible to achieve high resolution by realizing high density nozzles and formation of fine pitch wirings associated therewith, and it is possible to reduce the size of the droplet discharge head.

[First Embodiment]
As shown in FIG. 1, the ink jet recording apparatus 10 includes a sheet supply unit 12 that feeds out a sheet, a registration adjustment unit 14 that controls the attitude of the sheet, a recording head unit 16 that forms an image on a sheet by ejecting ink droplets. The recording unit 20 includes a maintenance unit 18 that performs maintenance of the recording head unit 16, and a discharge unit 22 that discharges a sheet on which an image is formed by the recording unit 20.

  The sheet supply unit 12 includes a stocker 24 in which sheets are stacked and stocked, and a transport device 26 that transports the sheets one by one from the stocker 24 to the registration adjusting unit 14.

  The registration adjusting unit 14 includes a loop forming unit 28 and a guide member 29 for controlling the posture of the paper. By passing through this portion, the skew is corrected using the stiffness of the paper and the conveyance timing is controlled. The recording unit 20 is entered.

  The discharge unit 22 stores the sheet on which the image is formed by the recording unit 20 in the tray 25 via the discharge belt 23.

  Between the recording head unit 16 and the maintenance unit 18, a paper conveyance path 104 for conveying the recording paper P is configured (the conveyance direction is indicated by an arrow H). The recording paper P is sandwiched between the star wheel 17 and the transport roll 19 and transported continuously (without stopping). Then, ink droplets are ejected from the recording head unit 16 to the paper, and an image is formed on the recording paper P.

  The maintenance unit 18 includes a maintenance device 21 that is disposed to face the ink jet recording head 32, and can perform capping, wiping, dummy jet, vacuum processing, and the like on the ink jet recording head 32.

  As shown in FIG. 2, each of the inkjet recording units 30 includes a plurality of inkjet recording heads 32 arranged in a direction orthogonal to the paper transport direction. In the ink jet recording head 32, a plurality of nozzles 84 are formed in a matrix. An image is recorded on the recording paper P by ejecting ink droplets from the nozzles 84 onto the recording paper P that is continuously transported through the paper transporting path 104. For example, in order to record a so-called full-color image, at least four inkjet recording units 30 are arranged corresponding to each color of YMCK.

  As shown in FIG. 3, the print area width by the nozzle 84 of each inkjet recording unit 30 is longer than the maximum sheet width PW of the recording sheet P on which image recording by the inkjet recording apparatus 10 is assumed, Image recording over the entire width of the recording paper P can be performed without moving the inkjet recording unit 30 in the paper width direction (so-called Full Width Array (FWA)). Here, the printing area is basically the maximum of the recording area obtained by subtracting the margin not to be printed from both ends of the sheet, but is generally larger than the maximum sheet width PW to be printed. This is because there is a possibility that the sheet is conveyed at an angle (skew) with respect to the conveyance direction, and there is a high demand for borderless printing.

  Next, the inkjet recording head 32 in the inkjet recording apparatus 10 configured as described above will be described in detail. FIG. 4 is a schematic view showing a cross-sectional configuration of the ink jet recording head 32, and FIG. 5 is a schematic view of a part of FIG.

  As shown in FIG. 6, the ink jet recording head 32 of the present embodiment includes a flow path substrate 80, a piezoelectric element substrate 50, a first upper substrate 70, and an ink pool member 90 stacked in this order from the lower side. It is configured.

  As shown in FIGS. 4, 5, and 6, nozzles 84 that eject ink droplets are formed in a matrix (see FIG. 2) on the flow path substrate 80, and each nozzle 84 communicates with the nozzle 84. A chamber 86 is formed. The pressure chamber 86 is filled with ink. Each pressure chamber 86 is partitioned by a pressure partition wall 82.

  The ink pool member 90 is provided with an ink supply port 92 that communicates with an ink tank (not shown). The ink pool member 90 forms an ink pool chamber 94 having a predetermined shape and volume with the upper substrate 70 disposed on the lower side, and the ink injected from the ink supply port 92 is the ink pool chamber. 94 is stored.

  The first upper substrate 70 includes a glass substrate 72 that is an insulator having a strength that can serve as a support. In this embodiment, glass is used, but other materials such as ceramics, silicone, and resin can be used.

  On the lower surface of the glass substrate 72 (hereinafter referred to as “opposing surface 72A”), a metal wiring 74 for energizing a drive IC 77 described later is formed. The metal wiring 74 is formed on the flat glass substrate 72 without a step, and is covered and protected with a resin film 76. The metal wiring 74 is provided with bumps 78. The bump 78 is electrically connected to the upper electrode 58 of the piezoelectric element substrate 50 described later, and is thicker than the thickness of a drive IC 77 described later mounted on the glass substrate 72. The drive IC 77 and the piezoelectric element 54 are electrically connected through the metal wiring 74 by the bumps 78.

  The glass substrate 72 is formed with a through-hole 73 for supplying the ink stored in the ink pool chamber 94 to the pressure chamber 86. The through-hole 73 is formed for each pressure chamber 86.

  A driving IC 77 is mounted on the facing surface 72 </ b> A of the glass substrate 72. The drive IC 77 is disposed at a position of the end of the glass substrate 72 that does not face a piezoelectric element 54 described later, and is housed between the piezoelectric element substrate 50 and the first upper substrate 70. The periphery of the drive IC 77 is sealed with a resin material 79.

  The piezoelectric element substrate 50 includes a vibration plate 52 and a piezoelectric element 54.

  The diaphragm 52 is disposed on the upper side of the flow path substrate 80 and constitutes the upper part of each pressure chamber 86. The diaphragm 52 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 the piezoelectric element 54 is energized (when a voltage is applied). It has become. The diaphragm 52 may be an insulating material such as glass.

  The piezoelectric elements 54 are arranged in a matrix and are provided for each pressure chamber 86 so as to cover the pressure chamber 86 when viewed in plan. A lower electrode 56 having one polarity is disposed on the lower surface of the piezoelectric element 54, and an upper electrode 58 having the other polarity is disposed on the upper surface of the piezoelectric element 54, and the lower electrode 56 side is bonded to the diaphragm 52. The upper electrode 58 side faces the first upper substrate 70. The diaphragm 52 made of metal (such as SUS) that contacts the lower electrode 56 also functions as a low-resistance GND wiring.

  A protective film 60 is laminated on the exposed portions of the piezoelectric element 54 and the lower electrode 56. A resin member 62 is disposed on the upper side of the protective film 60. The resin member 62 is formed with a contact hole 64 for connecting the bump 78 to the upper electrode 58 and a free space port 66 for preventing deformation of the diaphragm 52.

  Bumps 78 are connected on the upper electrode 58. The drive IC 77 and the piezoelectric element 54 are electrically connected through the metal wiring 74 by the bumps 78. This eliminates the need for individual wiring on the piezoelectric element substrate 50. A voltage is applied from the driving IC 77 to the piezoelectric element 54 at a predetermined timing, and the diaphragm 52 is bent and deformed in the vertical direction, whereby the ink filled in the pressure chamber 86 is pressurized, and an ink droplet is ejected from the nozzle 84. Discharge.

  A supply hole 50 </ b> A communicating with the pressure chamber 86 is formed in the piezoelectric element substrate 50. 50 A of supply holes are comprised by the diaphragm 52, the lower electrode 56, and the resin member 62 being penetrated. The supply hole 50A is a fine and precise hole and has a function of adjusting the flow path resistance of the ink. The supply hole 50 </ b> A communicates with the pressure chamber 86 by communicating with a horizontal channel 88 extending in the horizontal direction from the pressure chamber 86 of the channel substrate 80. The horizontal flow path 88 is slightly longer than the connection portion with the actual supply hole 50A in advance so that alignment with the supply hole 50A is possible (so as to ensure communication) when the inkjet recording head 32 is manufactured. Is provided.

  As shown in FIG. 4, on the upper side of the supply hole 50A, there is provided a rib partition wall 68 that constitutes a supply path 68A that communicates with the supply hole 50A and also communicates with the through-hole 73 of the first upper substrate 70. Yes. The diameter of the supply path 68A constituted by the rib partition wall 68 is substantially the same as that of the through-hole 73, and the diameter of the supply hole 50A is larger than that of the supply path 68A. The diameter of the supply path 68A is negligible with respect to the resistance.

  As shown in FIG. 6, the rib partition wall 68 is also disposed around the piezoelectric element 54 in addition to the position constituting the supply path 68 </ b> A, and like the bump 78, the drive IC 77 mounted on the first upper substrate 70. It is designed to be thicker than the thickness. By the rib partition walls 68, a hollow 61 is formed between the piezoelectric element substrate 50 and the first upper substrate 70. As shown in FIG. 5, the hollow 61 communicates with the atmosphere through an atmosphere communication port 63. This prevents the pressure in the hollow 61 from being changed due to the displacement of the diaphragm 52 due to the sealed state of the hollow 61 and prevents the internal air from thermally expanding during the manufacturing process. It is to do.

  In the ink jet recording head 32 configured as described above, the pressure chamber 86 is formed on the lower side of the piezoelectric element substrate 50, and the ink pool chamber 94 is formed on the upper side of the first upper substrate 70, and they do not exist on the same horizontal plane. It is configured as follows. Accordingly, the pressure chambers 86 can be arranged in a state of being close to each other, and the nozzles 84 can be arranged in a matrix at high density. Specifically, with the conventional FPC system electrical connection, the nozzle resolution is limited to 600 npi (nozzle per pitch), but with the system of the present invention, it is possible to easily arrange 1200 npi. In addition, the size can be reduced to 1/2 or less because the FPC is not used when the 600 npi nozzle arrangement is compared as an example.

  Further, since the ink pool chamber 94 is wide and the dead water area is small, it is possible to appropriately remove bubbles.

  Further, since the wirings from the individual piezoelectric elements 54 are lifted to the first upper substrate 70 side by the bumps 78, the metal wiring 74 may be formed on the flat glass substrate 72, and the metal wiring is formed on the piezoelectric element substrate 50. Compared with the case of forming (on the piezoelectric element substrate 50 side, a wiring having a step must be formed by the piezoelectric element 54), it can be formed easily.

  Further, since the driving IC 77 is mounted on the first upper substrate 70, the first upper substrate 70 and the piezoelectric element are formed in a region where the piezoelectric element 54 is not disposed, as in the case where the driving IC 77 is mounted on the piezoelectric element substrate 50. Large bumps for connecting to the substrate 50 are not necessary, and the inkjet recording head 32 can be miniaturized.

  In addition, since the drive IC 77 for applying a voltage to the piezoelectric element 54 is built in the ink jet recording head 32, the piezoelectric element 54 and the drive IC 77 are compared with the case where the drive IC 77 is mounted outside the ink jet recording head 32. The length of the metal wiring 74 that connects them can be shortened, whereby the resistance of the metal wiring 74 is reduced.

  In addition, since the drive IC 77 serving as a heat source is mounted on the first upper substrate 70, the temperature rise of the ink in the pressure chamber 86 can be suppressed as compared with the case where the drive IC 77 is mounted on the piezoelectric element substrate 50. . Thereby, variation in ink droplet volume due to uneven ink temperature in the pressure chamber 86 can be suppressed.

  Further, in the ink jet recording head 32 having the above-described configuration, the hollow 61 is formed by the rib partition walls 68, so that the ink is smaller than when the hollow 61 is not formed (when the hollow portion is filled with ink). It is possible to reduce the number of heterogeneous interfaces in contact with each other and to expand the options for the inner surface treatment process (for example, Au sputtering can be used).

  Further, since the hollow 61 is configured, the piezoelectric element 54 can be easily isolated from the ink, and deformation of the diaphragm 52 can be prevented from being hindered.

  Next, the manufacturing process of the inkjet recording head 32 configured as described above will be described in detail with reference to FIGS.

  As shown in FIG. 7, the inkjet recording head 32 is manufactured by separately forming and bonding (bonding) the first upper substrate 70, the piezoelectric element substrate 50, and the flow path substrate 80. First, the manufacturing process of the piezoelectric element substrate 50 will be described.

  As shown in FIG. 8A, first, a glass first support substrate 40 having a plurality of through holes 40A is prepared. The first support substrate 40 may be anything as long as it does not bend and is not limited to glass, but glass is preferable because it is hard and inexpensive. Known methods for producing the first support substrate 40 include blasting and femtosecond laser processing of a glass substrate, and exposure / development of a photosensitive glass substrate (for example, PEG3C manufactured by HOYA Corporation).

  Then, as shown in FIG. 8B, a resin adhesive 42 is applied to the upper surface (front surface) of the first support substrate 40, and as shown in FIG. 8C, the upper surface is made of metal (SUS or the like). The diaphragm 52 is adhered. At this time, the through hole 52A of the diaphragm 52 and the through hole 40A of the first support substrate 40 are not overlapped (not overlapped). Note that an insulating substrate such as glass may be used as the material of the diaphragm 52.

  Here, the through hole 52A of the diaphragm 52 is used for forming the supply hole 50A. In addition, the through hole 40A is provided in the first support substrate 40 in order to flow a chemical solution (solvent) into the interface between the first support substrate 40 and the vibration plate 52 in a later step. Therefore, the resin adhesive 42 is dissolved, This is because the first support substrate 40 is peeled off from the diaphragm 52. Furthermore, various materials used during manufacture leak from the lower surface (back surface) of the first support substrate 40 so as not to overlap the through holes 40A of the first support substrate 40 and the through holes 52A of the diaphragm 52. This is to prevent it from happening.

  Next, as shown in FIG. 8D, the lower electrode 56 is patterned on the upper surface of the diaphragm 52. Specifically, patterning is performed by metal film sputtering (film thickness: 500 mm to 3000 mm), resist formation by photolithography, patterning (RIE), and resist stripping by oxygen plasma. This lower electrode 56 becomes the ground potential.

  Next, as shown in FIG. 8E, a PZT film, which is the material of the piezoelectric element 54, and the upper electrode 58 are sequentially laminated on the upper surface of the lower electrode 56 by sputtering, and as shown in FIG. 8F. Then, the piezoelectric element 54 (PZT film) and the upper electrode 58 are patterned. Specifically, PZT film sputtering (film thickness 3 μm to 15 μm), metal film sputtering (film thickness 500 μm to 3000 μm), resist formation by photolithography, patterning (RIE), and resist stripping by oxygen plasma are performed.

  Examples of the lower and upper electrode materials include Au, Ir, Ru, and Pt that have high affinity with the PZT material that is a piezoelectric element and have heat resistance.

Thereafter, as shown in FIG. 8G, a protective film 60 composed of a low water permeable insulating film (SiOx film) is laminated on the upper surface of the lower electrode 56 and the upper electrode 58 exposed on the upper surface. Specifically, a photosensitive polyimide (for example, photosensitive polyimide Durimide 7520 manufactured by Fuji Film Arch Co., Ltd.), which is formed by depositing a low water-permeable insulating film (SiOx film) having a high dangling bond density by the Chemical Vapor Deposition (CVD) method. ) Is applied, exposed and developed, and the SiOx film is etched by the reactive ion etching (RIE) method using CF ₄ gas using the photosensitive polyimide as a mask. Although the SiOx film is used here as the low water permeable insulating film, it may be a SiNx film, a SiOxNy film, or the like.

  Next, as shown in FIG. 8H, a resin member 62 having ink resistance and flexibility, such as a polyimide-based, polyamide-based, epoxy-based, polyurethane-based, or silicone-based resin film, is formed on the upper surface of the protective film 60. Are stacked and patterned. It should be noted that the resin member 62 is prevented from being laminated on the portion where the bump 78 is joined (contact hole 64) and the portion located above the pressure chamber 86 (free space port 66). The reason why the resin member 62 is not formed in the portion located in the upper part of the pressure chamber is to prevent the deformation of the diaphragm 52 by the resin member 62 from being hindered. Specifically, a resin material is applied, cured by curing, and formed by resist formation (Si-containing resist) by photolithography, patterning (RIE), and resist removal by oxygen plasma.

  Next, as shown in FIG. 8I, rib partition walls 68 are formed on the resin member 62. The rib partition wall 68 is formed by laminating a photosensitive resin such as polyimide, polyamide, epoxy, polyurethane, or silicone having ink resistance and flexibility, and patterning by exposure and development.

  As described above, the piezoelectric element substrate 50 (with the first support substrate 40) is manufactured.

  Next, a manufacturing process of the first upper substrate 70 will be described. As shown in FIG. 9A, first, a glass substrate 72 made of glass is prepared. The glass substrate 72 is not limited to be made of glass as long as the glass substrate 72 does not bend and has a thickness that can serve as a support, but glass is preferable because it is hard and inexpensive. In the manufacture of the first upper substrate 70, the glass substrate 72 itself has a thickness (0.3 mm to 1.5 mm) that can ensure the strength to be a support, so that it is necessary to provide a separate support. There is no.

  Then, as shown in FIG. 9B, a metal film is laminated on the lower surface (front surface) of the glass substrate 72, and the metal wiring 74 is patterned. Specifically, an Al film (thickness 1 μm) is deposited by sputtering, a resist is formed by photolithography, an Al film is etched by RIE using a chlorine-based gas, and oxygen plasma is applied. The resist film is removed.

  Next, as shown in FIG. 9C, a resin film 76 is formed on the metal wiring 74. The resin film 76 is not laminated on the portion where the bump 78 for connection with the upper electrode 58 is bonded and the portion where the IC bump 77A for mounting the driving IC is bonded. Specifically, as the resin film 76, a photosensitive resin such as polyimide, polyamide, epoxy, polyurethane, or silicone having ink resistance and flexibility (for example, photosensitive polyimide manufactured by Fuji Film Arch Co., Ltd.). Durimide 7320) is laminated and patterned by exposure and development.

  Then, as shown in FIG. 9D, bumps 78 connected to the metal wiring 74 are formed. For the formation of the bumps 78, electroplating, electroless plating, ball bumps, screen printing, or the like can be applied. The height of the bump 78 is set higher than the height of the rib partition wall 68 in order to facilitate the bonding with the upper electrode 58 at the time of bonding with the piezoelectric element substrate 50.

  Next, as shown in FIG. 9E, the drive IC 77 is flip-chip mounted on the metal wiring 74 via the IC bump 77A. At this time, the drive IC 77 is processed to a predetermined thickness (70 μm to 300 μm) in a grinding process performed in advance at the end of the semiconductor wafer process. As a method for forming the IC bump 77A, electroplating, electroless plating, ball bumps, screen printing, or the like can be applied.

  Next, as shown in FIG. 9F, the exposed portion of the drive IC 77 is sealed with a resin material 79. Specifically, it is performed by applying a resin material. By sealing the drive IC 77 with the resin material 79 in this way, the drive IC 77 can be protected from the external environment, and damage in a later process, for example, the completed piezoelectric element substrate 50 is divided into the ink jet recording head 32 by dicing. It is possible to avoid damage caused by water and grinding pieces.

  Next, a through-hole 73 for allowing ink to pass through the glass substrate 72 is formed. The through-hole 73 is formed by first patterning a resist R on the upper surface of the glass substrate 72 as shown in FIG. Then, a through-hole 73 is formed as shown in FIG. 9 (H) by drilling by sandblasting and stripping the resist.

  As described above, the first upper substrate 70 is manufactured.

  Next, a process of joining (joining) the piezoelectric element substrate 50 and the first upper substrate 70 will be described.

  As shown in FIG. 10A, the rib partition wall 68 side of the piezoelectric element substrate 50 and the bump 78 forming side of the first upper substrate 70 are opposed to each other, and both are bonded (bonded) by thermocompression bonding. That is, the rib partition walls 68 are bonded to the glass substrate 72 and the resin film 76, and the bumps 78 are bonded to the upper electrode 58.

  At this time, since the height of the bump 78 is higher than the height of the rib partition wall 68, the bump 78 is automatically bonded to the upper electrode 58 by bonding the rib partition wall 68 to the glass substrate 72 and the resin film 76. The That is, since the height adjustment of the bump 78 is easy (being easily crushed), the formation of the supply path 68A and the hollow 61 by the rib partition wall 68 and the connection of the bump 78 can be easily performed.

  Next, as shown in FIG. 10B, an adhesive stripping solution (for example, an organic ethanolamine solvent) is injected from the through hole 40A of the first support substrate 40 to selectively dissolve the resin adhesive 42. Then, the first support substrate 40 is peeled from the piezoelectric element substrate 50. As a result, as shown in FIG. 10C, a bonded substrate of the first upper substrate 70 and the piezoelectric element substrate 50 is completed.

  Next, the manufacturing process of the flow path substrate 80 will be described.

  As shown in FIG. 11A, first, a second support substrate 44 made of glass having a plurality of through holes 44A is prepared. Similarly to the first support substrate 40, the second support substrate 44 may be anything as long as it does not bend, and is not limited to glass. However, glass is preferable because it is hard and inexpensive. Known methods for producing the second support substrate 44 include blast processing and femtosecond laser processing of a glass substrate, and exposure / development of a photosensitive glass substrate (for example, PEG3C manufactured by HOYA Corporation).

  Then, as shown in FIG. 11B, a resin adhesive 46 is applied to the upper surface (front surface) of the second support substrate 44, and as shown in FIG. 11C, the resin substrate is applied to the upper surface (front surface). 80A (for example, an amideimide substrate having a thickness of 0.1 mm to 0.5 mm) is bonded. Then, as shown in FIG. 11D, the upper surface of the resin substrate 80A is pressed against the mold K, and is heated and pressurized. Thereafter, as shown in FIG. 11E, the mold K is released from the resin substrate 80A, thereby forming the pressure chamber 86, the nozzle 84, and the like, thereby forming the flow path substrate 80 (with the second support substrate 44). Is completed.

  When the flow path substrate 80 is thus completed, as shown in FIG. 12A, the vibration plate 52 side of the piezoelectric element substrate 50 and the side where the pressure chamber 86 of the flow path substrate 80 is formed are joined by thermocompression bonding. (Join). Then, as shown in FIG. 12B, an adhesive stripping solution is injected from the through hole 44A of the second support substrate 44 to selectively dissolve the resin adhesive 46, whereby the second support substrate 44. Is peeled off from the flow path substrate 80.

  Thereafter, as shown in FIG. 12C, the surface from which the second support substrate 44 is peeled is subjected to a polishing process using an abrasive mainly composed of alumina or an RIE process using oxygen plasma. The layer is removed and the nozzle 84 is opened. Then, as shown in FIG. 12D, a fluorine material F (for example, Cytop manufactured by Asahi Glass Co., Ltd.) as a water repellent is applied to the lower surface where the nozzle 84 is opened.

  Then, as shown in FIG. 12E, an ink pool member 90 is joined to the upper surface of the first upper substrate 70 to complete the ink jet recording head 32. As shown in FIG. The chamber 94 and the pressure chamber 86 can be filled with ink.

  In the above embodiment, the metal wiring 74 is provided only on the lower surface side of the glass substrate 72. However, as shown in FIG. 13, the through wiring 74A connected to the metal wiring 74 on the glass substrate 72, and the through wiring An upper surface wiring 74B connected to 74A and provided on the upper surface side of the glass substrate 72 may be formed (the upper surface wiring 74B is covered with a resin film 76B). Thus, by forming the upper surface wiring 74B, the wiring area can be expanded without changing the size of the inkjet recording head 32. The upper surface wiring 74B can be used as an input signal line or the like. Since the upper surface wiring 74B is disposed outside the ink jet recording head 32, it can be easily connected to a control board (not shown).

  In the above embodiment, the drive IC 77 is mounted on the lower surface side of the first upper substrate 70, but the drive IC 77 may be mounted on the upper surface side of the first upper substrate 70 as shown in FIG. In this case, the through wiring 74A and the upper surface wiring 74B described above are formed, and the driving IC 77 and the upper surface wiring 74B are joined by the IC bumps 77A. Thus, by disposing the driving IC 77 outside the ink jet recording head 32, the heat dissipation characteristics can be improved.

  Further, as shown in FIG. 15, the ink pool chamber 94 may be expanded, and the drive IC 77 may be disposed in the ink pool chamber 94 on the upper surface of the first upper substrate 70. If it is in the ink pool chamber 94, the generated driving IC 77 is cooled by ink, and the heat dissipation characteristics can be improved (water cooling effect).

  In the above embodiment, the driving IC 77 is mounted on the first upper substrate 70. However, the driving IC is not necessarily mounted on the first upper substrate 70. The metal wiring 74 or the upper surface wiring is not necessarily mounted on the first upper substrate 70. 74B may be pulled out and connected to another substrate, and a driving IC may be mounted on this substrate. That is, as shown in FIG. 24, the upper surface wiring 74 </ b> B may be drawn out to the PWB substrate 110 by a flexible substrate (FPC) 114 and the drive IC 112 may be mounted on the PWB substrate 110.

  Next, the operation of the inkjet recording apparatus 10 including the inkjet recording head 32 manufactured as described above will be described. First, when an electrical signal for instructing printing is sent to the inkjet recording apparatus 10, one recording sheet P is picked up from the stocker 24 and conveyed to the recording unit 20 by the conveying device 26.

  On the other hand, in the ink jet recording unit 30, ink has already been injected (filled) from the ink tank into the ink pool chamber 94 of the ink jet recording head 32 via the ink supply port 92, and the ink filled in the ink pool chamber 94 passes through the through-hole. 73, the supply path 68A and the supply hole 50A are supplied (filled) to the pressure chamber 86. At this time, a meniscus in which the ink surface is slightly recessed toward the pressure chamber 86 is formed at the tip (ejection port) of the nozzle 84.

  An image based on the image data is recorded on the recording paper P by selectively ejecting ink droplets from the plurality of nozzles 84 of the ink jet recording head 32 while the recording paper P is transported at a predetermined transport speed. That is, a voltage is applied to a predetermined piezoelectric element 54 at a predetermined timing by the drive IC 77, the diaphragm 52 is bent and deformed in the vertical direction (vibrated out of plane), and the ink in the pressure chamber 86 is pressurized. Then, an image is formed by ejecting ink droplets from a predetermined nozzle 84.

  The recording paper P is conveyed toward the discharge unit 22 while forming an image, and is discharged to the tray 25 by the paper discharge belt 23. Thereby, the printing process (image recording) on the recording paper P is completed.

  In this embodiment, the example of the FWA corresponding to the paper width has been described. However, the ink jet recording head of the present invention is not limited to this, and is applied to a partial width array (PWA) apparatus having a main scanning mechanism and a sub-scanning mechanism. Can also be applied. In particular, since the present invention is effective for realizing a high-density nozzle arrangement, it is suitable for FWA that requires one-pass printing.

  In addition, in the inkjet recording apparatus 10 of the above-described embodiment, the inkjet recording units 30 of black, yellow, magenta, and cyan are mounted on the carriage 12 and selectively selected from the inkjet recording heads 32 of these 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.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected and shown in the part similar to 1st Embodiment, and detailed description is abbreviate | omitted.

  The schematic configuration of the ink jet recording apparatus 100 of the present embodiment is the same as that of the ink jet recording apparatus 10 of the first embodiment shown in FIGS.

  The ink jet recording head 34 mounted on the ink jet recording apparatus 100 is the same as the ink jet recording head 32 of the first embodiment shown in FIG.

  The ink jet recording head 34 of the present embodiment is configured by stacking and arranging a flow path substrate 80, a piezoelectric element substrate 50, a second upper substrate 71, and an ink pool member 90 in this order from the lower side. The flow path substrate 80, the piezoelectric element substrate 50, and the ink pool member 90 have the same configuration as in the first embodiment.

  The second upper substrate 71 includes a glass substrate 72 that is an insulator having a strength that can serve as a support. In this embodiment, for example, ceramics, silicone, resin, etc. can be used in addition to glass.

  Metal wiring 74 is formed on the facing surface 72 </ b> A of the glass substrate 72. The metal wiring 74 is formed on the flat glass substrate 72 without a step. A thin film transistor 75 is formed on the facing surface 72A for each piezoelectric element 54 and connected to the metal wiring 74. The second upper substrate 71 is a so-called SOG (System On Glass) substrate. The metal wiring 74 and the thin film transistor 75 are covered and protected with a resin film 76. The metal wiring 74 is provided with bumps 78. The bump 78 is electrically connected to the upper electrode 58 of the piezoelectric element substrate 50. The thin film transistor 75 and the piezoelectric element 54 are electrically connected via the metal wiring 74 by the bumps 78.

  The glass substrate 72 is formed with a through-hole 73 for supplying ink stored in the ink pool chamber 94 to the pressure chamber 86. The through-hole 73 is formed for each pressure chamber 86.

  As shown in FIG. 16, rib partition walls 68 are provided above the supply holes 50 </ b> A formed in the piezoelectric element substrate 50. The configuration of the rib partition wall 68 is also the same as in the first embodiment. Due to the rib partition walls 68, a hollow 61 is formed between the piezoelectric element substrate 50 and the second upper substrate 71.

  Also in the ink jet recording head 34 having the above-described configuration, the pressure chamber 86 is formed below the piezoelectric element substrate 50, and the ink pool chamber 94 is formed above the second upper substrate 71, and they do not exist on the same horizontal plane. It is configured as follows. Accordingly, the pressure chambers 86 can be arranged in a state of being close to each other, and the nozzles 84 can be arranged in a matrix at high density.

  Further, since the ink pool chamber 94 is wide and the dead water area is small, it is possible to appropriately remove bubbles.

  Further, since the wirings from the individual piezoelectric elements 54 are lifted to the second upper substrate 71 side by the bumps 78, the metal wiring 74 may be formed on the flat second upper substrate 71. Compared with the case of forming the wiring (if the piezoelectric element substrate 50 side, the wiring having a step must be formed by the piezoelectric element 54), it can be formed easily.

  In addition, since the thin film transistor 75 is formed on the second upper substrate 71, in order to connect the large size driving IC 77 and the driving IC required when the driving IC 77 is mounted on the piezoelectric element substrate 50 to the second upper substrate 71. Large bumps are not required, and the inkjet recording head 34 can be downsized.

  In addition, since the thin film transistor 75 serving as a heat source is mounted on the second upper substrate 71, the temperature rise of the ink in the pressure chamber 86 can be suppressed as compared with the case where the thin film transistor 75 is mounted on the piezoelectric element substrate 50. . Thereby, variation in ink droplet volume due to uneven ink temperature in the pressure chamber 86 can be suppressed.

  Further, in the ink jet recording head 34 having the above configuration, since the hollow 61 is formed by the rib partition walls 68, the ink is compared with the case where the hollow 61 is not formed (when the hollow portion is filled with ink). It is possible to reduce the number of heterogeneous interfaces in contact with each other and to expand the options for the inner surface treatment process (for example, Au sputtering can be used).

  Further, since the hollow 61 is configured, the piezoelectric element 54 can be easily isolated from the ink, and deformation of the diaphragm 52 can be prevented from being hindered.

  Next, the manufacturing process of the inkjet recording head 34 configured as described above will be described in detail with reference to FIGS.

    As shown in FIG. 18, the ink jet recording head 34 is manufactured by separately forming and bonding (bonding) the second upper substrate 71, the piezoelectric element substrate 50, and the flow path substrate 80. Since the manufacturing process of the piezoelectric element substrate 50 and the flow path substrate 80 is the same as that of the first embodiment, the detailed description is omitted, and the manufacturing process of the second upper substrate 71 will be described.

  As shown in FIG. 19A, first, a glass substrate 72 made of glass is prepared. The glass substrate 72 is not limited to be made of glass as long as the glass substrate 72 does not bend and has a thickness that can serve as a support, but glass is preferable because it is hard and inexpensive. In the production of the second upper substrate 71, the glass substrate 72 itself has a thickness (0.3 mm to 1.5 mm) that can secure the strength to be a support, so that it is necessary to provide a separate support. There is no.

  Next, as shown in FIG. 19B, a metal film is laminated on the lower surface (front surface) of the glass substrate 72, and the metal wiring 74 is patterned. Specifically, an Al film (thickness 1 μm) is deposited by sputtering, a resist is formed by photolithography, an Al film is etched by RIE using a chlorine-based gas, and oxygen plasma is applied. The resist film is removed.

  Further, the thin film transistor 75 is formed on the facing surface 72A that is the same as the surface on which the metal wiring 74 is formed. The thin film transistor 75 is formed by a general low temperature Poly Si TFT process.

  Then, a resin film 76 is formed on the metal wiring 74 and the thin film transistor 75. It should be noted that the resin film 76 is not laminated on the portion where the bump 78 for connection with the upper electrode 58 is joined. Specifically, as the resin film 76, a photosensitive resin such as polyimide, polyamide, epoxy, polyurethane, or silicone having ink resistance and flexibility (for example, photosensitive polyimide manufactured by Fuji Film Arch Co., Ltd.). Durimide 7320) is laminated and patterned by exposure and development.

  Then, as shown in FIG. 19C, bumps 78 connected to the metal wiring 74 are formed. For the formation of the bumps 78, electroplating, electroless plating, ball bumps, screen printing, or the like can be applied. The height of the bump 78 is set higher than the height of the rib partition wall 68 in order to facilitate the bonding with the upper electrode 58 at the time of bonding with the piezoelectric element substrate 50.

  Next, a through-hole 73 for allowing ink to pass through the glass substrate 72 is formed. The through-hole 73 is formed by first patterning a resist on the upper surface of the glass substrate 72 as shown in FIG. Then, a through-hole 73 is formed as shown in FIG. 19 (E) by perforating by sandblasting and removing the resist.

  As described above, the second upper substrate 71 is manufactured.

  Next, a bonding (bonding) process between the piezoelectric element substrate 50 and the second upper substrate 71 will be described.

  As shown in FIG. 20A, the rib partition wall 68 side of the piezoelectric element substrate 50 and the bump 78 forming side of the second upper substrate 71 are opposed to each other, and both are bonded (bonded) by thermocompression bonding. That is, the rib partition walls 68 are bonded to the glass substrate 72 and the resin film 76, and the bumps 78 are bonded to the upper electrode 58.

  At this time, since the height of the bump 78 is higher than the height of the rib partition wall 68, the bump 78 is automatically bonded to the upper electrode 58 by bonding the rib partition wall 68 to the glass substrate 72 and the resin film 76. The That is, since the height adjustment of the bump 78 is easy (being easily crushed), the formation of the supply path 68A and the hollow 61 by the rib partition wall 68 and the connection of the bump 78 can be easily performed.

  Next, as shown in FIG. 20B, an adhesive stripping solution (for example, an organic ethanolamine solvent) is injected from the through hole 40A of the first support substrate 40 to selectively dissolve the resin adhesive 42. Then, the first support substrate 40 is peeled from the piezoelectric element substrate 50. As a result, as shown in FIG. 20C, the bonded substrate of the second upper substrate 71 and the piezoelectric element substrate 50 is completed.

  Next, joining (joining) of the joined body of the flow path substrate 80, the piezoelectric element substrate 50, and the second upper substrate 71 will be described.

  As shown in FIG. 21A, the diaphragm 52 side of the piezoelectric element substrate 50 and the side on which the pressure chamber 86 of the flow path substrate 80 is formed are joined (joined) by thermocompression bonding. Then, as shown in FIG. 21B, an adhesive stripping solution (organic ethanolamine solution) is injected from the through hole 44A of the second support substrate 71 to selectively dissolve the resin adhesive 46. Then, the second support substrate 44 is peeled from the flow path substrate 80.

  Thereafter, as shown in FIG. 21C, the surface from which the second support substrate 71 has been peeled is subjected to a polishing process using an abrasive mainly composed of alumina or an RIE process using oxygen plasma. The layer is removed and the nozzle 84 is opened. Then, as shown in FIG. 21D, a fluorine material F (for example, Cytop manufactured by Asahi Glass Co., Ltd.) as a water repellent is applied to the lower surface where the nozzle 84 is opened.

  21E, the ink pool member 90 is joined to the upper surface of the second upper substrate 71 to complete the ink jet recording head 34. As shown in FIG. The chamber 94 and the pressure chamber 86 can be filled with ink.

  In the above embodiment, the metal wiring 74 is provided only on the lower surface side of the glass substrate 72. However, as shown in FIG. 22, the through wiring 74A connected to the metal wiring 74 on the glass substrate 72, and the through wiring An upper surface wiring 74B connected to 74A and provided on the upper surface side of the glass substrate 72 may be formed (the upper surface wiring 74B is covered with a resin film 76B). Thus, by forming the upper surface wiring 74B, the wiring area can be expanded without changing the size of the inkjet recording head 34. The upper surface wiring 74B can be used as an input signal line or the like. Since the upper surface wiring 74B is disposed outside the ink jet recording head 34, it can be easily connected to a control board (not shown).

  In the above embodiment, the thin film transistor 75 is formed on the lower surface side of the second upper substrate 71. However, as shown in FIG. 23, the thin film transistor 75 is formed in the ink pool chamber 94 on the upper surface side of the second upper substrate 71. May be. By disposing the thin film transistor 75 in the ink pool chamber 94, the thin film transistor 75 that has generated heat is cooled by ink, and heat dissipation characteristics can be improved (water cooling effect).

  In the above embodiment, the thin film transistor 75 is formed on the second upper substrate 71. However, the thin film transistor is not necessarily formed on the second upper substrate 71. The thin film transistor may be formed on another substrate, and the metal wiring 74 or the upper surface wiring 74B may be drawn from the second upper substrate 71 and connected to this substrate.

  Since the operation of the ink jet recording apparatus 100 equipped with the ink jet recording head 34 having the above-described configuration is the same as that of the first embodiment, detailed description thereof is omitted.

  Also in this embodiment, an example of FWA corresponding to the paper width has been described. However, the inkjet recording head of the present invention is not limited to this, and can be applied to a PWA apparatus.

  Further, 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 34 according to the present invention can be applied to all droplet ejecting apparatuses.

1 is a schematic diagram illustrating an overall configuration of an ink jet recording apparatus according to a first embodiment. It is the schematic which shows arrangement | positioning of the inkjet recording unit of 1st Embodiment. It is a figure which shows the printing area | region by the inkjet recording unit of 1st Embodiment. 1 is a cross-sectional view illustrating a configuration of an ink jet recording head according to a first embodiment. FIG. 2 is a plan view of a part of the ink jet recording head according to the first embodiment. It is sectional drawing which decomposes | disassembles and shows the inkjet recording head of 1st Embodiment for every principal part. It is explanatory drawing of the whole process which manufactures the inkjet recording head of 1st Embodiment. It is explanatory drawing which shows process (A)-(F) which manufactures a piezoelectric element board | substrate. It is explanatory drawing which shows the process (G)-(J) which manufactures a piezoelectric element board | substrate. It is explanatory drawing which shows process (A)-(E) which manufactures a 1st upper board | substrate. It is explanatory drawing which shows the process (F)-(H) which manufactures a 1st upper board | substrate. It is explanatory drawing which shows process (A)-(C) which joins a piezoelectric element board | substrate and a 1st upper board | substrate. It is explanatory drawing which shows the process of manufacturing a flow-path board | substrate. It is explanatory drawing which shows process (A)-(B) which joins a flow-path board | substrate to the conjugate | zygote of a piezoelectric element board | substrate and a 1st upper board | substrate. It is explanatory drawing which shows process (C)-(D) which joins a flow-path board | substrate to the conjugate | zygote of a piezoelectric element board | substrate and a 1st upper board | substrate. It is explanatory drawing which shows the process (E)-(F) which joins an ink pool member to a piezoelectric element board | substrate, a 1st upper board | substrate, a flow-path board | substrate, and a conjugate | zygote. It is the schematic which shows the structure of the modification of the inkjet recording head of 1st Embodiment. It is the schematic which shows the structure of the other modification of the inkjet recording head of 1st Embodiment. It is the schematic which shows the structure of the other modification of the inkjet recording head of 1st Embodiment. It is sectional drawing which shows the structure of the inkjet recording head of 2nd Embodiment. It is sectional drawing which decomposes | disassembles and shows the inkjet recording head of 2nd Embodiment for every principal part. It is explanatory drawing of the whole process of manufacturing the inkjet recording head of 2nd Embodiment. It is explanatory drawing which shows process (A)-(E) which manufactures a 2nd upper board | substrate. It is explanatory drawing which shows process (A)-(C) which joins a piezoelectric element board | substrate and a 2nd upper board | substrate. It is explanatory drawing which shows the process (A)-(B) which joins a flow-path board | substrate to the conjugate | zygote of a piezoelectric element board | substrate and a 2nd upper substrate. It is explanatory drawing which shows process (C)-(D) which joins a flow-path board | substrate to the conjugate | zygote of a piezoelectric element board | substrate and a 2nd upper board | substrate. It is explanatory drawing which shows the process (E)-(F) which joins an ink pool member to a piezoelectric element board | substrate, a 2nd upper board | substrate, a flow-path board | substrate, and a conjugate | zygote. It is the schematic which shows the structure of the modification of the inkjet recording head of 2nd Embodiment. It is the schematic which shows the structure of the other modification of the inkjet recording head of 2nd Embodiment. It is the schematic which shows the structure of the other modification of the inkjet recording head of 1st Embodiment. It is a schematic sectional drawing which shows the structure of the conventional inkjet recording head. It is a schematic plan view which shows the structure of the conventional inkjet recording head. It is a schematic perspective view which shows the structure of the conventional inkjet recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 32 Inkjet recording head 34 Inkjet recording head 50 Piezoelectric element substrate 52 Diaphragm 54 Piezoelectric element 61 Hollow 63 Atmospheric communication port 68 Rib partition wall 68A Supply path 70 First upper substrate 71 Second upper substrate 73 Through port 74A Through wiring 74 Metal wiring 74B Top surface wiring 75 Thin film transistor 77 Driving IC
78 Bump 80 Flow path substrate 84 Nozzle 86 Pressure chamber 90 Ink pool member 94 Ink pool chamber

Claims (15)

A nozzle for discharging droplets;
A pressure chamber in communication with the nozzle and filled with fluid;
A piezoelectric element substrate including a diaphragm constituting a part of the pressure chamber, and a piezoelectric element for displacing the diaphragm;
A fluid pool chamber that is provided on the opposite side of the pressure chamber with the piezoelectric element substrate interposed therebetween, and pools fluid supplied to the pressure chamber;
An upper portion disposed between the fluid pool chamber and the piezoelectric element substrate so as to face the piezoelectric element substrate while being spaced apart and formed with a through-hole for supplying fluid from the fluid pool chamber to the pressure chamber A substrate,
Wiring formed on the upper substrate and connected to at least driving means for driving the piezoelectric element;
A connecting member disposed between the opposing upper substrate and the piezoelectric element, and electrically connecting the wiring and the piezoelectric element;
A droplet discharge head comprising: The wiring includes an opposing wiring formed on an opposing surface of the upper substrate facing the piezoelectric element substrate;
The droplet discharge head according to claim 1. The wiring is configured to include a through wiring penetrating the opposing surface and a back surface on the back side of the opposing surface, and a back wiring connected to the through wiring and disposed on the back surface,
The liquid droplet ejection head according to claim 1, wherein:   4. The liquid droplet ejection head according to claim 1, wherein the driving unit is mounted on a substrate different from the upper substrate. 5.   4. The droplet discharge head according to claim 1, wherein the driving unit is mounted on the upper substrate. 5.   The liquid droplet ejection head according to claim 5, wherein the driving unit is mounted on the back surface.   The liquid droplet ejection head according to claim 6, wherein the driving unit is disposed in the fluid pool chamber.   The liquid droplet ejection head according to claim 5, wherein the driving unit is mounted on the facing surface of the upper substrate.   The liquid droplet ejection head according to claim 1, wherein the driving unit is configured by an integrated circuit.   9. The liquid droplet ejection head according to claim 1, wherein the driving unit includes a thin film transistor.   11. The liquid droplet ejection head according to claim 1, wherein one through hole is formed for one piezoelectric element. 11. A fluid supply path that is provided between the upper substrate and the piezoelectric element substrate and communicates with the through hole to supply a fluid to the pressure chamber, and between the upper substrate and the piezoelectric element substrate. Further comprising a rib partition wall forming a cavity,
The droplet discharge head according to claim 1, wherein:   The droplet discharge head according to claim 12, wherein the cavity communicates with the atmosphere.   The liquid droplet ejection head according to claim 1, wherein the nozzles are arranged in a matrix.   A liquid droplet ejection apparatus comprising the liquid droplet ejection head according to claim 1.

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