JP6206666B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

  The present invention relates to a liquid ejecting head that ejects liquid from a nozzle opening and a liquid ejecting apparatus including the liquid ejecting head.

  A liquid ejecting head that ejects liquid droplets from a nozzle opening communicating with a pressure generating chamber by deforming a piezoelectric element to cause a pressure fluctuation in the liquid in the pressure generating chamber is known. A typical example of the liquid ejecting head is an ink jet recording head that ejects ink droplets as droplets.

  An ink jet recording head includes, for example, a piezoelectric element on one side of a flow path forming substrate provided with a pressure generating chamber communicating with a nozzle opening, and deforms a diaphragm by driving the piezoelectric element, thereby The ink is caused to change in pressure, and ink droplets are ejected from the nozzle openings.

  In recent years, inkjet heads have been required to be low in cost and high in density. In order to realize this, it is essential to make the distance (nozzle pitch) between the nozzle openings provided in the head as small (narrow) as possible. Accordingly, it is necessary to reduce the distance between the piezoelectric elements according to the nozzle pitch. However, when the distance between the piezoelectric elements becomes small, it becomes difficult to connect each wiring connected to the plurality of piezoelectric elements and the driving IC by a wire bonding technique, and adjacent wire bonding comes into contact with each other. Problems such as short-circuiting occur.

  Therefore, instead of wire bonding, a structure in which a COF (Chip On Film) substrate, which is a wiring substrate on which a driving IC is mounted, and a piezoelectric element are connected by a bonding process using anisotropic conductive paste (ACP), or on a protective substrate A structure in which the driving IC and the piezoelectric element are flip-chip mounted, that is, an FCB (Flip Chip Bonding) structure has been proposed (see, for example, Patent Documents 1 and 2).

  These wiring structures are provided with a wiring layer and a wiring substrate for electrically connecting the electrodes of the piezoelectric element and the driving IC. A metal made of copper, copper alloy, gold or the like is used for such a wiring layer or a mounting portion of the wiring board.

JP 2012-101227 A Japanese Patent Application Laid-Open No. 2007-066965

  However, when copper or copper alloy is used as the wiring layer, the manufacturing cost can be relatively suppressed. However, since copper is likely to cause migration, the piezoelectric element is likely to burn out from the end due to migration. Occurs. For this reason, it is usually necessary to provide an insulating film made of alumina or a plating layer made of nickel or gold as a protective film on the wiring layer made of copper or a copper alloy. On the other hand, when such a protective film is provided, there arises a problem that the manufacturing cost increases.

  Such a problem exists not only in an ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

  In view of such circumstances, the present invention provides a liquid ejecting head and a liquid ejecting head that can suppress metal migration without a protective film, prevent burnout from occurring at the end of the piezoelectric element, and reduce the manufacturing cost. An object is to provide an apparatus.

An aspect of the present invention that solves the above-described problems includes a piezoelectric element in which a first electrode, a piezoelectric layer, and a second electrode are stacked on a flow path forming substrate, and a first wiring configured as a wiring of the first electrode. A liquid ejecting head comprising a layer, a protective substrate that forms a sealing space for the piezoelectric element, and a drive circuit for driving the piezoelectric element, wherein the piezoelectric element is the sealing member of the protective substrate. The first wiring layer is extended to the inside of a through hole provided outside the space, and the first wiring layer is electrically insulated from the second electrode of the piezoelectric element and connected to the first electrode. Provided on the second electrode, and insulated from the first wiring layer by an adhesive layer that joins the protective substrate between the sealing space and the through hole and the flow path forming substrate. A metal layer is provided, and the first wiring layer is filled in the through hole. Lying in the liquid jet head, characterized in that is covered by the potting agent.
In this aspect, the adhesive layer that insulates the metal layer and the first wiring layer functions as a protective film for suppressing metal migration. Accordingly, it is possible to realize a liquid ejecting head that can suppress metal migration without a protective film, prevent burnout from occurring at the end of the piezoelectric element, and reduce the manufacturing cost.

  Here, it is preferable that the first wiring layer contains copper. According to this, a copper wiring without a protective film is realized, and the migration of copper can be suppressed and the manufacturing cost can be further reduced.

  Here, the adhesive layer is preferably composed of a thermosetting epoxy resin. According to this, metal migration can be further suppressed, and stress concentration on the joint portion at the outer end of the sealed space can be reduced.

  Here, the side surface of the protective substrate on the outer end side of the sealing space is inclined toward the inner side of the protective substrate, and the through hole is connected to the first wiring layer, and the protection It is preferable that a second wiring layer is provided that extends through the side surface of the substrate and is electrically connected to the drive circuit. According to this, the second wiring layer can be formed smoothly along the inclined surface of the protective substrate, and the second wiring layer can be formed relatively easily.

  Here, it is preferable that the second wiring layer contains gold. According to this, wiring resistance can be lowered.

  Here, it is preferable that the through hole is provided with a wiring board connected to the first wiring layer and electrically connected to the driving circuit. According to this, electrical connection between the first wiring layer and the drive circuit can be reliably performed via the wiring board.

  Here, it is preferable that a plating layer containing gold is provided at a connection portion between the first wiring layer and the terminal of the wiring board. According to this, the resistance of the connection part can be lowered.

Another aspect of the invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the above aspects.
In this aspect, a liquid ejecting apparatus that can suppress metal migration without a protective film, prevent burnout from occurring at the end of the piezoelectric element, and reduce the manufacturing cost is realized.

FIG. 2 is a partially exploded perspective view illustrating a schematic configuration of the recording head according to the first embodiment. FIG. 3 is a plan view of the recording head according to the first embodiment. FIG. 2 is a cross-sectional view and a main part enlarged view of a recording head according to Embodiment 1. FIG. 3 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 3 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 3 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 3 is a cross-sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a partially exploded perspective view illustrating a schematic configuration of a recording head according to a second embodiment. FIG. 6 is a plan view of a recording head according to a second embodiment. FIG. 6 is a cross-sectional view and a main part enlarged view of a recording head according to a second embodiment. 1 is a diagram illustrating a schematic configuration of a recording apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a partially exploded perspective view showing a schematic configuration of an ink jet recording head which is an example of a liquid jet head according to Embodiment 1 of the present invention. FIG. 2 is a plan view of the ink jet recording head. 3 is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in the drawing, a pressure generating chamber 12 is formed in a flow path forming substrate 10 provided in an ink jet recording head I which is an example of a liquid ejecting head of the present embodiment. The pressure generating chambers 12 partitioned by the plurality of partition walls 11 are arranged in parallel along the direction in which the plurality of nozzle openings 21 for discharging the same color ink are arranged in parallel. Hereinafter, this direction is referred to as a direction in which the pressure generating chambers 12 are arranged side by side or a first direction X. Further, the direction orthogonal to the first direction X is hereinafter referred to as a second direction Y.

  In addition, an ink supply path 13 and a communication path 14 are partitioned by a plurality of partition walls 11 on one end side in the longitudinal direction of the pressure generating chamber 12 of the flow path forming substrate 10, that is, on one end side in the second direction Y. ing. On the outside of the communication passage 14 (on the side opposite to the pressure generation chamber 12 in the second direction Y), a communication portion that constitutes a part of the manifold 100 serving as a common ink chamber (liquid chamber) of each pressure generation chamber 12. 15 is formed. That is, the flow path forming substrate 10 is provided with a liquid flow path including a pressure generation chamber 12, an ink supply path 13, a communication path 14, and a communication portion 15.

  On one side of the flow path forming substrate 10, that is, the surface where the liquid flow path such as the pressure generation chamber 12 opens, a nozzle plate 20 having a nozzle opening 21 communicating with each pressure generation chamber 12 is provided with an adhesive. Or a heat-welded film or the like. In other words, the nozzle openings 21 are arranged in the nozzle plate 20 in the first direction X.

  A diaphragm 50 is formed on the other surface side of the flow path forming substrate 10. The diaphragm 50 according to the present embodiment includes an elastic film 51 formed on the flow path forming substrate 10 and an insulator film 52 formed on the elastic film 51. The liquid flow path such as the pressure generation chamber 12 is formed by anisotropically etching the flow path forming substrate 10 from one surface, and the other surface of the liquid flow path such as the pressure generation chamber 12 is a diaphragm. 50 (elastic film 51).

  On the insulator film 52, a first electrode 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0.05 μm. A piezoelectric element 300 composed of the second electrode 80 is formed.

  As shown in the figure, the first electrode 60 constituting the piezoelectric element 300 is divided for each pressure generating chamber 12 and constitutes an individual electrode that is independent for each active portion described later. The first electrode 60 is formed with a width narrower than the width of the pressure generation chamber 12 in the first direction X of the pressure generation chamber. That is, in the first direction X of the pressure generation chamber 12, the end portion of the first electrode 60 is located inside the region facing the pressure generation chamber 12. In the second direction Y, both end portions of the first electrode 60 are extended to the outside of the pressure generation chamber 12. The material of the first electrode 60 must be a material that does not oxidize when the piezoelectric layer 70 described later is formed and can maintain conductivity. For example, platinum (Pt), iridium (Ir) ) Or a conductive oxide typified by lanthanum nickel oxide (LNO) is preferably used.

  Further, as the first electrode 60, an adhesion layer for securing an adhesion force may be used between the above-described conductive material and the diaphragm 50. As the adhesion layer, zirconium, titanium oxide, or the like can be used in addition to titanium.

  The piezoelectric layer 70 is continuously provided in the first direction X so that the second direction Y has a predetermined width. The width of the piezoelectric layer 70 in the second direction Y is larger than the length of the pressure generation chamber 12 in the second direction Y. Therefore, in the second direction Y of the pressure generation chamber 12, the piezoelectric layer 70 is provided to the outside of the pressure generation chamber 12.

  In the second direction Y of the pressure generating chamber 12, the end of the piezoelectric layer 70 on the ink supply path 13 side is located outside the end of the first electrode 60. That is, the end portion of the first electrode 60 is covered with the piezoelectric layer 70. The end of the piezoelectric layer 70 on the nozzle opening 21 side is located on the inner side (pressure generation chamber 12 side) of the end of the first electrode 60, and the end of the first electrode 60 on the nozzle opening 21 side. The portion is not covered with the piezoelectric layer 70.

The piezoelectric layer 70 is a crystal film (perovskite crystal) having a perovskite structure made of a ferroelectric ceramic material having an electromechanical conversion effect and formed on the first electrode 60. As a material of the piezoelectric layer 70, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT) or a material obtained by adding a metal oxide such as niobium oxide, nickel oxide, or magnesium oxide to the piezoelectric material is used. be able to. Specifically, lead titanate (PbTiO ₃ ), lead zirconate titanate (Pb (Zr, Ti) O ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La), TiO ₃ ) ), Lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti) O ₃ ), lead magnesium titanate zirconate titanate (Pb (Zr, Ti) (Mg, Nb) O ₃ ), etc. Can do. In the present embodiment, lead zirconate titanate (PZT) is used as the piezoelectric layer 70.

The material of the piezoelectric layer 70 is not limited to a lead-based piezoelectric material including lead, and a lead-free piezoelectric material not including lead can also be used. Examples of lead-free piezoelectric materials include bismuth ferrate ((BiFeO ₃ ), approximately “BFO”), barium titanate ((BaTiO ₃ ), approximately “BT”), and sodium potassium niobate ((K, Na). ) (NbO ₃ ), approximately “KNN”), potassium sodium lithium niobate ((K, Na, Li) (NbO ₃ )), potassium sodium tantalate niobate ((K, Na, Li) (Nb, Ta) ) O ₃ ), potassium bismuth titanate ((Bi _1/2 K _1/2 ) TiO ₃ , approximately “BKT”), bismuth sodium titanate ((Bi _1/2 Na _1/2 ) TiO ₃ , approximately “BNT )), Bismuth manganate (BiMnO ₃ , approximately “BM”), bismuth, potassium, titanium and iron, and a composite oxide having a perovskite structure (x [(B _{i x} K _{1 -X) TiO 3] - (1} -x) [BiFeO 3], approximately "BKT-BF"), bismuth, iron, composite oxide having a perovskite structure containing barium and titanium ((1-x) [BiFeO 3 ] -X [BaTiO ₃ ], substantially “BFO-BT”), or a metal added with manganese, cobalt, chromium or the like ((1-x) [Bi (Fe _1-y M _y ) O ₃ ] -X [BaTiO ₃ ] (M is Mn, Co or Cr)).

  As will be described in detail later, the piezoelectric layer 70 is a liquid phase method such as a sol-gel method or a MOD (Metal-Organic Decomposition) method, or a PVD (Physical Vapor Deposition) method (gas phase) such as a sputtering method or a laser ablation method. Method).

  In such a piezoelectric layer 70, recesses 71 corresponding to the respective partition walls 11 are formed. The width of the recess 71 in the first direction X is substantially the same as or wider than the width of each partition 11 in the first direction. As a result, the rigidity of the portion of the vibration plate 50 that opposes the end portion of the pressure generation chamber 12 in the second direction Y (the arm portion of the vibration plate 50) is suppressed, so that the piezoelectric element 300 can be favorably displaced. it can.

  The second electrode 80 is provided on the opposite surface side of the piezoelectric layer 70 from the first electrode 60 and constitutes a common electrode common to the plurality of active portions 310. In the present embodiment, the second electrode 80 includes a first layer 81 provided on the piezoelectric layer 70 side and a second layer 82 provided on the opposite side of the first layer 81 from the piezoelectric layer 70. It has.

  The first layer 81 is preferably made of a material capable of satisfactorily forming an interface with the piezoelectric layer 70 and exhibiting piezoelectric characteristics, such as iridium (Ir), platinum (Pt), palladium (Pd), gold (Au), titanium ( A metal material such as Ti) and a conductive oxide represented by lanthanum nickel oxide (LNO) are preferably used. The first layer 81 may be a stacked layer of a plurality of materials. In this embodiment, a laminate of iridium and titanium (iridium is in contact with the piezoelectric layer 70) is used. The first layer 81 is formed by a liquid phase method such as a PVD (Physical Vapor Deposition) method (vapor phase method) such as a sputtering method or a laser ablation method, a sol-gel method, a MOD (Metal-Organic Decomposition) method, or a plating method. Can be formed. In addition, the characteristics of the piezoelectric layer 70 can be improved by performing a heat treatment after the formation of the first layer 81. Such a first layer 81 is formed only on the piezoelectric layer 70, that is, only on the surface of the piezoelectric layer 70 opposite to the flow path forming substrate 10.

  The second layer 82 constituting the second electrode 80 is made of a conductive material such as iridium (Ir), platinum (Pt), palladium (Pd), gold (Au), titanium (Ti) or the like. Materials can be used. Of course, the second layer 82 may be a single material of the metal material or a plurality of materials in which a plurality of materials are mixed. Further, titanium or the like may be provided between the first layer 81 and the second layer 82. In the present embodiment, a laminate of iridium and titanium (iridium is in contact with the first layer 81) is used as the second layer 82.

  In the present embodiment, such a second layer 82 is continuous over the first layer 81, the side surface of the piezoelectric layer 70 where the first layer 81 is not provided, and the first electrode 60. Is provided. Incidentally, the second layer 82 on the first layer 81 and the second layer 82 on the first electrode 60 are electrically disconnected. That is, the second layer 82 on the first layer 81 and the second layer 82 on the first electrode 60 are formed of the same layer but are electrically discontinuous. Here, the removing unit 83 is configured to pass the second electrode 80 on the piezoelectric layer 70, that is, the first layer 81 and the second layer 82 in the thickness direction (the stacking direction of the first layer 81 and the second layer 82). And electrically cut through. Such a removal unit 83 is provided so as to penetrate the second electrode 80 in the thickness direction continuously in the first direction X, and the pressure generation chamber 12 side of the removal unit 83 serves as a common electrode. On the other hand, the side opposite to the pressure generation chamber 12 of the removal portion 83 is stacked on the individual first electrode 60 drawn to the outside of the pressure generation chamber 12, and is the same as the first electrode 60. It becomes the 1st wiring layer 91 (individual lead electrode) patterned so that it might become individual for every piezoelectric element 300. FIG.

  The piezoelectric element 300 including the first electrode 60, the piezoelectric layer 70, and the second electrode 80 is provided on the flow path forming substrate 10 so as to be deformable, and constitutes the piezoelectric actuator of the present embodiment. Displacement occurs when a voltage is applied between the two electrodes 80. That is, by applying a voltage between both electrodes, a piezoelectric strain is generated in the piezoelectric layer 70 sandwiched between the first electrode 60 and the second electrode 80. A portion where piezoelectric distortion occurs in the piezoelectric layer 70 when a voltage is applied to both electrodes 60 and 80 is referred to as an active portion 310. On the other hand, a portion where no piezoelectric distortion occurs in the piezoelectric layer 70 is referred to as an inactive portion. Further, in the active part 310 in which piezoelectric distortion occurs in the piezoelectric layer 70, a part facing the pressure generation chamber 12 is referred to as a flexible part, and a part outside the pressure generation chamber 12 is referred to as a non-flexible part.

  In the present embodiment, all of the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are continuously provided to the outside of the pressure generation chamber 12 in the second direction Y. That is, the active part 310 is continuously provided to the outside of the pressure generation chamber 12. Therefore, a portion of the active portion 310 that faces the pressure generation chamber 12 of the piezoelectric element 300 is a flexible portion, and a portion outside the pressure generation chamber 12 is a non-flexible portion.

  Further, the end of the active part 310 in the first direction X is defined by the first electrode 60. The end portion of the first electrode 60 in the first direction X is provided in a region facing the pressure generation chamber 12. Therefore, the end portion of the active portion 310 in the first direction X is provided in the flexible portion, and in the first direction X, the stress at the boundary between the active portion 310 and the inactive portion is caused by the diaphragm. It is released by deformation. For this reason, destruction such as burnout and cracks due to stress concentration at the end portion of the active portion 310 in the first direction X can be suppressed.

  In such a piezoelectric element 300, since the second electrode 80 covers the piezoelectric layer 70, current does not leak between the first electrode 60 and the second electrode 80, and the piezoelectric element 300 is destroyed. Can be suppressed.

  The first electrode 60 and the second electrode 80 of the piezoelectric element 300 have a first wiring layer 91 (individual lead electrode), a first metal layer 92, a second metal layer 93, and a third electrode. The metal layer 94 (common lead electrode) is connected.

  The first wiring layer 91 is electrically separated from the second electrode 80 by the removing unit 83 described above and is separated for each piezoelectric element 300 on the first layer 81 and the second layer 82 separated for each piezoelectric element 300. The first electrode 60 is provided and extends outward from the end of the piezoelectric layer 70, and extends to the outside of the sealing space 31 of the protective substrate 30.

  The first metal layer 92 is continuously extended in the first direction X direction at the end of the second electrode 80 on the removal portion 83 side. The second metal layer 93 is continuously extended in the first direction X direction on the side opposite to the removal portion 83 of the second electrode 80. The first metal layer 92 and the second metal layer 93 are connected by the third metal layer 94 outside the first direction X, and the third metal layer 94 is the same as the first wiring layer 91. And extends to the outside of the sealing space 31 of the protective substrate 30.

  Here, the first metal layer 92 and the second metal layer 93 are boundaries between both ends of the pressure generation chamber 12 in the second direction Y, that is, between the flexible portion and the non-flexible portion of the piezoelectric element 300. Since it is provided so as to straddle the boundary and is provided continuously in the direction of the first direction X, it has a function of suppressing the destruction of the piezoelectric layer 70 due to stress concentration at the boundary. In addition, since the common lead electrode is not substantially formed on the flexible portion, it is possible to suppress a decrease in displacement of the active portion 310.

  The first wiring layer 91, the first metal layer 92, the second metal layer 93, and the third metal layer 94 are collectively referred to as a lead electrode 90. An adhesive layer 191 provided on the path forming substrate 10 side and a conductive layer 192 provided on the adhesive layer 191 are provided.

  The adhesion layer 191 is for improving the adhesion between the second electrode 80, the first electrode 60, the diaphragm 50, and the conductive layer 192, and includes at least one of titanium (Ti) and tungsten (W). It is made of material or nickel or nickel-chromium alloy (nichrome). In this embodiment, titanium tungsten (TiW) is used as the adhesion layer 191.

  The conductive layer 192 is provided on the adhesion layer 191 and is formed of a material containing gold (Au) or copper (Cu). Although the details of the first wiring layer 91 and the first metal layer 92 will be described later, the first wiring layer 91 and the first metal layer 92 are insulated between the sealing space 31 and the through hole 33 by the adhesive layer 35 that functions as a protective film. A protective film for suppressing metal migration is not necessary.

  On the flow path forming substrate 10 on which the piezoelectric element 300 is formed, there is a protective substrate 30 that covers the flow path forming substrate 10 and forms a recessed sealing space 31 that defines a space for sealing the piezoelectric element 300. Bonded by the adhesive layer 35. The protective substrate 30 is provided with a manifold portion 32 that constitutes a part of the manifold 100. The manifold portion 32 penetrates the protective substrate 30 in the thickness direction and is formed across the width direction of the pressure generating chamber 12, and communicates with the communication portion 15 of the flow path forming substrate 10. Further, a through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided on the opposite side of the protective substrate 30 from the manifold portion 32. The through hole 33 is provided so that the connection end of the first wiring layer 91 and the connection end of the third metal layer 94 described above are exposed in the through hole 33. The connection end of the first wiring layer 91 and the connection end of the third metal layer 94 are covered with the potting agent 200 filled in the through hole 33.

  On the protective substrate 30, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded. The sealing film 41 is made of a material having low rigidity and flexibility, and one surface of the manifold portion 32 is sealed by the sealing film 41. The fixing plate 42 is made of a hard material such as metal. Since the area of the fixing plate 42 facing the manifold 100 is an opening 43 that is completely removed in the thickness direction, one surface of the manifold 100 is sealed only with a flexible sealing film 41. Has been.

  A drive circuit 120 for driving the piezoelectric elements 300 arranged in parallel is fixed on the protective substrate 30. For example, a circuit board or a semiconductor integrated circuit (IC) can be used as the drive circuit 120. The drive circuit 120, the first wiring layer 91 constituting the individual lead electrode, and the third metal layer 94 constituting the common lead electrode are the side surfaces of the protective substrate 30 on the pressure generation chamber 12 side of the through hole 33. Are electrically connected to each other through a second wiring layer 95. In the present embodiment, gold (Au) is used as the second wiring layer 95.

  Here, the side surface of the protective substrate 30 provided with at least the second wiring layer 95 of the through hole 33 is inclined toward the inner side of the protective substrate 30. As described above, since the side surface of the protective substrate 30 is inclined toward the inside thereof, the second wiring layer 95 can be formed relatively easily, and between the piezoelectric element 300 and the drive circuit 120. Can be conducted well.

  Further, the protective substrate 30 between the sealing space 31 and the through hole 33 and the flow path forming substrate 10 are joined by the adhesive layer 35, and the wall surface of the protective substrate 30 between the sealing space 31 and the through hole 33. The adhesion surface (the lower surface of the protective substrate 30) abuts on a portion where the first wiring layer 91 and the first metal layer 92 are separately provided via the removal portion 83.

  In the present embodiment, the adhesive layer 35 at the joint portion of the wall surface between the sealing space 31 and the through hole 33 is a relatively thin first adhesive portion 35a that joins the first wiring layer 91 and the wall surface. A second adhesive portion 35b having substantially the same thickness as the first adhesive portion 35a for joining the first metal layer 92 and the wall surface, and the first adhesive portion 35a and the second adhesive portion 35b And a third adhesive portion 35c which is a portion corresponding to the removal portion 83. Here, the 3rd adhesion part 35c has joined piezoelectric layer 70 and a wall surface, and thickness is thicker than the 1st adhesion part 35a and the 2nd adhesion part 35b.

  The second wiring layer 95 is formed at the outer end of the sealing space 31 of the protective substrate 30 through the protruding portion of the adhesive (adhesive layer 35) of the first adhesive portion 35a. Here, the thickness of the first bonding portion 35a and the amount of protruding adhesive affect the wiring state. Specifically, if the amount of protruding adhesive is large, the contact surface between the protruding portion of the adhesive and the second wiring layer 95 becomes large, and the second wiring layer 95 is easily bent in the thickness direction. Therefore, the adhesive force between the side surface of the first adhesive portion 35a and the second wiring layer 95 is reduced, and the second wiring layer 95 is easily peeled when the piezoelectric actuator is driven. On the contrary, if the amount of protrusion of the adhesive is too small and does not protrude from the outer end portion of the protective substrate 30, the side surface of the first adhesive portion 35 a and the second wiring layer 95 are not in contact with each other. It tends to occur.

  For this reason, it is preferable to preliminarily define the film thickness of each bonded portion of the adhesive layer 35. Thereby, the amount of the adhesive protruding from the outer end portion of the sealing space 31 can be adjusted, and peeling of the second wiring layer 95 can be suppressed and disconnection can be prevented.

  Specifically, in the cross section obtained by cutting the piezoelectric element 300 in the thickness direction of the piezoelectric layer 70, the thickness A of the first adhesive portion 35a and the thickness B of the second adhesive portion 35b are substantially the same. That is, approximately 1: 1 is preferable. Thereby, the thickness A of the 1st adhesion part 35a and the thickness B of the 2nd adhesion part 35b can be made thin as much as possible, and the excess adhesive agent can be absorbed by the 3rd adhesion part 35c. Further, in the first adhesive portion 35a, the amount of the adhesive protruding from the outer end portion of the sealing space 31 can be easily adjusted, and the second wiring layer 95 provided at the protruding portion of the first adhesive portion 35a. The contact surface with can be reduced.

  Furthermore, the ratio of the thickness A of the first adhesive portion 35a or the thickness B of the second adhesive portion 35b to the thickness C of the third adhesive portion 35c is 1: 2 to 1: 9. Is preferred. Thereby, the presence of the third adhesive portion 35c can suppress the amount of the adhesive protruding to the first adhesive portion 35a side and the amount of the adhesive protruding to the second adhesive portion 35b side. The amount of protrusion can be adjusted to be smaller. Further, by reducing the amount of the adhesive protruding to the first adhesive portion 35a side, the contact surface between the protruding portion of the adhesive of the first adhesive portion 35a and the second wiring layer 95 can be made smaller. Thus, it is possible to prevent a decrease in the adhesion between the protruding portion and the second wiring layer 95. Thereby, peeling of the second wiring layer 95 can be further suppressed.

  Further, in the direction in which the first wiring layer 91 is drawn out of the sealing space 31 of the protective substrate 30, the length of the first adhesive portion 35a is D, and the length of the second adhesive portion 35b is E. If the length of the third adhesive portion 35c is F, the ratio of the length D of the first adhesive portion 35a to the length F of the third adhesive portion 35c, or the length of the second adhesive portion 35b The ratio of the length E to the length F of the third adhesive portion 35c is preferably 1: 1.3 to 1: 3. Thereby, the amount of the adhesive protruding can be easily adjusted, and the protective substrate 30 and the flow path forming substrate 10 between the sealing space 31 and the through hole 33 can be stably bonded.

  Further, as described above, the first wiring layer 91 and the first metal layer 92 are connected to the second electrode 80 and the second metal layer 93 at the joint portion provided between the sealing space 31 and the through hole 33. And the adhesive layer 35.

  In the present invention, the adhesive layer 35 functions as an adhesive and also functions as a protective film (insulating film) for suppressing metal migration, so that metal migration is suppressed even without the protective film, and the piezoelectric element end portion Can be prevented from being burned out. Specifically, the first wiring layer 91 and the first metal layer 92, and the second electrode 80 and the second metal layer 93 are insulated by the adhesive layer 35 at the outer end portion of the sealing space 31. Thus, copper migration can be suppressed.

  As a result, it is possible to prevent burnout from the end of the piezoelectric element caused by metal migration. Furthermore, since the wiring structure can be mainly composed of low-cost copper wiring without a protective film, the manufacturing process can be simplified and the manufacturing cost can be reduced. In the present embodiment, gold is used for the second wiring layer 95, but it is of course possible to use copper or a copper alloy.

  Here, examples of the adhesive constituting the adhesive layer 35 include thermosetting adhesives such as an epoxy resin, a silicone resin, a urethane resin, a polyester resin, a polyethylene resin, a polyimide resin, and a polyamideimide resin. Among these, it is preferable to use a thermosetting epoxy resin that is highly effective in suppressing metal migration and can relieve stress during curing. Such adhesives can be used alone or in combination of two or more.

  Moreover, it does not specifically limit as a potting agent with which the inside of the through-hole 33 is filled, Resin similar to the adhesive agent mentioned above can be used individually by 1 type or in combination of 2 or more types.

  In such an ink jet recording head I of this embodiment, after taking ink from an ink introduction port connected to an external ink supply means (not shown) and filling the interior from the manifold 100 to the nozzle opening 21, the drive circuit A voltage is applied between each of the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12 in accordance with the recording signal from. As a result, the diaphragm 50 is bent and deformed together with the piezoelectric element 300 to increase the pressure in each pressure generating chamber 12, and an ink droplet is ejected from each nozzle opening 21.

  Here, a method for manufacturing the ink jet recording head of the present embodiment will be described. 4 to 7 are cross-sectional views showing a method for manufacturing the ink jet recording head.

  As shown in FIG. 4A, an elastic film 51 made of silicon dioxide is formed by thermally oxidizing a flow path forming substrate wafer 110, which is a silicon wafer, and then the elastic film 51 and the elastic film 51 are formed on the elastic film 51. An insulator film 52 made of an oxide film of a different material is formed. In the present embodiment, the diaphragm 50 is formed by the elastic film 51 and the insulator film 52.

  Next, the first electrode 60 is formed on the entire surface of the insulator film 52. The material of the first electrode 60 is not particularly limited, but when lead zirconate titanate (PZT) is used as the piezoelectric layer 70, it is desirable that the material has little change in conductivity due to diffusion of lead oxide. For this reason, platinum, iridium, etc. are used suitably as a material of the 1st electrode 60. FIG. Moreover, the 1st electrode 60 can be formed by sputtering method, PVD method (physical vapor deposition method), etc., for example.

  Next, a crystal seed layer 61 made of titanium (Ti) is formed on the first electrode 60. By providing the crystal seed layer 61 on the first electrode 60 in this way, the piezoelectric layer 70 is formed when the piezoelectric layer 70 is formed on the first electrode 60 via the crystal seed layer 61 in a later step. Therefore, the piezoelectric layer 70 suitable as an electromechanical conversion element can be obtained. The crystal seed layer 61 functions as a seed that promotes crystallization when the piezoelectric layer 70 is crystallized.

  Next, in this embodiment, the piezoelectric layer 70 made of lead zirconate titanate (PZT) is formed. Here, in this embodiment, a so-called sol-gel in which a so-called sol in which a metal complex is dissolved / dispersed in a solvent is applied, dried, gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed using the method. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, using a MOD (Metal-Organic Decomposition) method, a PVD (Physical Vapor Deposition) method such as a sputtering method or a laser ablation method. Also good. That is, the piezoelectric layer 70 may be formed by either a liquid phase method or a gas phase method.

  As a specific procedure for forming the piezoelectric layer 70, first, as shown in FIG. 4B, a piezoelectric precursor film 73 that is a PZT precursor film is formed on the crystal seed layer 61. That is, a sol (solution) containing a metal complex is applied onto the flow path forming substrate wafer 110 on which the first electrode 60 (crystal seed layer 61) is formed (application step). Next, the piezoelectric precursor film 73 is heated to a predetermined temperature and dried for a predetermined time (drying step). For example, in this embodiment, the piezoelectric precursor film 73 can be dried by holding at 170 to 180 ° C. for 3 to 30 minutes.

Next, the dried piezoelectric precursor film 73 is degreased by heating to a predetermined temperature and holding for a certain time (degreasing step). For example, in this embodiment, the piezoelectric precursor film 73 is degreased by heating to a temperature of about 300 to 400 ° C. and holding for about 3 to 30 minutes. Note that the degreasing here, the organic components contained in the piezoelectric precursor film 73, for _example, is to be detached as _{NO 2, CO 2, H 2} O or the like.

  Next, as shown in FIG. 4C, the piezoelectric precursor film 73 is crystallized by heating to a predetermined temperature and holding for a certain period of time to form a piezoelectric film 74 (firing step). In this firing step, the piezoelectric precursor film 73 is preferably heated to 700 ° C. or higher. In the firing step, it is preferable that the temperature rising rate is 50 ° C./sec or more. Thereby, the piezoelectric film 74 having excellent characteristics can be obtained.

  The crystal seed layer 61 formed on the first electrode 60 diffuses into the piezoelectric film 74. Of course, the crystal seed layer 61 may remain as titanium between the first electrode 60 and the piezoelectric film 74, or may remain as titanium oxide.

  In addition, as a heating apparatus used in such a drying process, a degreasing process, and a baking process, for example, a hot plate, an RTP (Rapid Thermal Processing) apparatus that heats by irradiation with an infrared lamp, or the like can be used.

  Next, as shown in FIG. 4D, when the first piezoelectric film 74 is formed on the first electrode 60, the first electrode 60 and the first piezoelectric film 74 are formed on their side surfaces. Are simultaneously patterned so as to be inclined. The patterning of the first electrode 60 and the first piezoelectric film 74 can be performed by dry etching such as ion milling, for example.

  Next, as shown in FIG. 5A, after patterning the first piezoelectric film 74 and the first electrode 60, the side surface of the first electrode 60, the side surface of the first electrode 60, and the first layer are formed. An intermediate crystal seed layer 62 is formed across the side surface of the piezoelectric film 74 and the piezoelectric film 74. As in the crystal seed layer 61, the intermediate crystal seed layer 62 can be made of titanium, lanthanum nickel oxide, or the like.

  Next, as shown in FIG. 5B, a piezoelectric body comprising a plurality of layers of piezoelectric films 74 by repeating the piezoelectric film forming process including the coating process, the drying process, the degreasing process and the firing process described above a plurality of times. Layer 70 is formed.

  Incidentally, the second and subsequent piezoelectric films 74 are continuous over the insulator film 52, on the side surfaces of the first electrode 60 and the first piezoelectric film 74, and on the first piezoelectric film 74. Formed. Since the intermediate crystal seed layer 62 is formed in the region where the second and subsequent piezoelectric films 74 are formed, the preferred orientation direction of the second and subsequent piezoelectric films 74 is formed by the intermediate crystal seed layer 62. Is controlled. The intermediate crystal seed layer 62 functions as a seed that promotes crystallization when the piezoelectric layer 70 is crystallized. Even if the piezoelectric layer 70 is baked, all of the intermediate crystal seed layer 62 diffuses into the piezoelectric layer 70. Moreover, a part may remain as it is or as an oxide.

  Next, as shown in FIG. 5C, the first layer 81 of the second electrode 80 is formed on the piezoelectric layer 70. Although not particularly shown in the present embodiment, first, an iridium layer having iridium on the piezoelectric layer 70 and a titanium layer having titanium on the iridium layer are laminated. Note that the iridium layer and the titanium layer can be formed by a sputtering method, a CVD method, or the like. Thereafter, the piezoelectric layer 70 on which the iridium layer and the titanium layer are formed is further reheated (post-annealed). By performing the reheating treatment in this way, even if damage is caused when an iridium layer or the like is formed on the second electrode 80 side of the piezoelectric layer 70, the reheating treatment can be performed to damage the piezoelectric layer 70. Thus, the piezoelectric characteristics of the piezoelectric layer 70 can be improved.

  Next, as shown in FIG. 6A, the first layer 81 and the piezoelectric layer 70 are patterned corresponding to each pressure generating chamber 12. In the present embodiment, a mask (not shown) formed in a predetermined shape is provided on the first layer 81, and the first layer 81 and the piezoelectric layer 70 are etched through the mask, and patterning is performed by so-called photolithography. Examples of the patterning of the piezoelectric layer 70 include dry etching such as reactive ion etching and ion milling.

  Next, as shown in FIG. 6B, over one surface side of the flow path forming substrate wafer 110 (the surface side on which the piezoelectric layer 70 is formed), that is, on the first layer 81, the piezoelectric material A second layer 82 made of, for example, iridium (Ir) is formed and patterned on the patterned side surface of the layer 70, the insulator film 52, the first electrode 60, and the like to form the second electrode 80. Form. In the patterning of the second layer 82, a part of the first layer 81 is simultaneously patterned to form the removal portion 83. Thereby, the active part 310 of the piezoelectric element 300 is defined.

  Next, as shown in FIG. 6C, over one surface side of the flow path forming substrate wafer 110 (the surface side on which the piezoelectric layer 70 is formed), that is, on the second electrode 80, the piezoelectric material For example, an adhesion layer 191 made of titanium tungsten (TiW) and a conductive layer 192 made of gold (Au) are formed on the patterned side surface of the layer 70, the insulator film 52, the first electrode 60, and the like. The first wiring layer 91 (individual lead electrode) is formed by stacking. Note that a method for forming the adhesion layer 191 and the conductive layer 192 is not particularly limited, and examples thereof include a sputtering method and an electroless plating method.

  Next, as shown in FIG. 6D, the conductive layer 192 is patterned into a predetermined shape. That is, a mask having a predetermined shape is formed on the conductive layer 192 (not shown), and the conductive layer 192 is etched through the mask for patterning. Note that the conductive layer 192 may be etched by wet etching or dry etching.

  Next, as shown in FIG. 6E, the adhesion layer 191 is patterned by wet etching. In this embodiment, using the conductive layer 192 as a mask, the adhesion layer 191 is wet-etched with an etchant containing hydrogen peroxide and an alkali component. As a result, the first wiring layer 91 (individual lead electrode), the first metal layer 92 and the second metal layer 93 (common lead electrode) are formed, and one of the piezoelectric layer 70 and the second electrode 80 is formed. Part is exposed.

  At this time, since the etching solution for etching the adhesion layer 191 is a solution containing hydrogen peroxide, ammonia overwater, and an alkali component, electrolytic corrosion occurs in the electrodes (the first electrode 60 and the second electrode 80). Can be suppressed.

  In this embodiment, the conductive layer 192 is formed by electroless plating using copper (Cu) having high conductivity and low cost. Since copper easily undergoes migration, it is usually necessary to provide an insulating film made of alumina or the like and a plating layer made of palladium, nickel, gold, or the like as a protective film on the conductive layer 192. However, in the present invention, the adhesive layer 35 functions as a protective film for suppressing metal migration, and the first wiring layer 91 and the first metal layer 92 are located between the sealing space 31 and the through hole 33. Since the adhesive layer 35 is insulated from the second electrode 80 and the second metal layer 93, a protective film is not necessary.

  Next, as shown in FIG. 7A, the first wiring layer 91 is connected to the upper surface of the protective substrate 30 through the side surface of the adhesive layer 35 and the side surface of the protective substrate 30. A second wiring layer 95 that is extended and electrically connected to the drive circuit 120 is formed. In the present embodiment, gold (Au) is used as the second wiring layer 95. The second wiring layer 95 is formed by a sputtering method and includes gold (Au) as a main component. In the present embodiment, as described above, the side surface of the protective substrate 30 is inclined toward the inside thereof, and the second wiring layer 95 is smoothly formed along the inclined surface of the protective substrate 30. Thereby, the second wiring layer 95 can be formed relatively easily.

  Next, as shown in FIG. 7B, the drive circuit 120 is fixed on the protective substrate 30. Specifically, an adhesive is applied to the lower surface of the drive circuit 120 and pressed against the protective substrate 30 to press and mount the terminal portion of the drive circuit 120 on the second wiring layer 95. In the present embodiment, after the second wiring layer 95 is formed, the drive circuit 120 is FCB-mounted. Of course, the mounting of the drive circuit 120 is not limited to this.

  Thereafter, although not shown in the drawings, a flow path formation is performed after bonding a protective substrate wafer 130 which is a silicon wafer and becomes a plurality of protective substrates 30 to the piezoelectric element 300 side of the flow path forming substrate wafer 110 via an adhesive. The substrate wafer 110 is thinned to a predetermined thickness.

  Next, a mask film is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape, and the flow path forming substrate wafer 110 is anisotropically etched using an alkaline solution such as KOH through the mask film ( By performing wet etching, the pressure generating chamber 12, the ink supply path 13, the communication path 14, the communication portion 15 and the like corresponding to the piezoelectric element 300 are formed.

  Thereafter, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer are removed by cutting, for example, by dicing. Then, the nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer. The path forming substrate wafer 110 and the like are divided into one chip size channel forming substrate 10 and the like as shown in FIG. 1 to obtain the ink jet recording head of this embodiment. The through hole 33 of the protective substrate 30 is filled with the potting agent 200 up to the top surface.

(Embodiment 2)
FIG. 8 is a partially exploded perspective view showing a schematic configuration of an ink jet recording head which is an example of a liquid jet head according to Embodiment 2 of the present invention. FIG. 9 is a plan view of the ink jet recording head. 10 is a cross-sectional view taken along the line BB ′ in FIG. In addition, the same code | symbol is attached | subjected to the same member as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 8 to 10, in the second embodiment, the side surface of the protective substrate 30 </ b> A on the outer end side of the sealing space 31 is formed perpendicular to the flow path forming substrate 10. In the through-hole 33 outside the sealing space 31, the flexible wiring board 201 that electrically connects the first wiring layer 91 and the drive circuit 120 is substantially parallel to the side surface of the protective substrate 30A. Is provided. The wiring board 201 has an L shape, and a terminal is provided in a portion corresponding to the L shape, and the terminal of the wiring board 201 is joined to the outer end portion of the first wiring layer 91 through a joining means (not shown). Is done. Examples of the bonding means include bonding with an adhesive such as anisotropic conductive adhesive (ACP) and non-conductive adhesive (NCP), and metal bonding with solder. Note that a plating layer containing gold is preferably provided in a joint portion between the first wiring layer 91 and the wiring substrate 201 in order to reduce resistance. Further, the wiring board 201 is supported by a support member (not shown) in addition to joining to the outer end portion of the first wiring layer 91.

  A drive circuit 120 is fixed on the wiring board 201 on the surface opposite to the L-shaped portion of the wiring board 201. As the wiring substrate 201, for example, a flexible printed circuit board (FPC) such as a chip on film (COF) or a tape carrier package (TCP) can be used. In the present embodiment, a chip on film (COF) is used.

  The through-hole 33 is filled with a potting agent 200 so as to cover a portion where the first wiring layer 91 is exposed and a joint portion between the first wiring layer 91 and the terminal of the wiring substrate 201.

  Further, in the present embodiment, the adhesive layer 35 is provided so as to protrude from the joining portion of the outer end portion of the sealed space 31 by the adhesive layer 35. As described above, the adhesive layer 35 is an adhesive and functions as a protective film for suppressing metal migration. Therefore, the adhesive layer 35 is exposed to the outside from the outer end portion of the sealing space 31, and protrudes from the adhesive layer 35. The covered first wiring layer 91 is suppressed from copper migration. Further, since the first wiring layer 91 exposed in the through hole 33 is covered with the potting agent 200, for example, the first wiring layer 91 is formed by configuring the potting agent 200 with the same material as the adhesive layer 35. Copper migration can be suppressed. Furthermore, in this embodiment, the adhesive layer 36 is provided on the contact surface between the protruding portion of the adhesive layer 35 and the potting agent 200. As a result, the adhesion between the protruding portion of the adhesive layer 35 and the potting agent 200 is further enhanced, and the copper migration of the first wiring layer 91 at the outer end of the sealing space 31 is reliably prevented. Note that the adhesive layer 36 may not be provided.

  In the ink jet recording head II having such a configuration, the first wiring layer 91 and the first metal layer 92 bonded to the protective substrate 30A at the outer end portion of the sealing space 31, the second electrode 80, and the second electrode 80. The metal layer 93 is insulated by the adhesive layer 35, and the first wiring layer 91 exposed outside the outer end portion of the sealing space 31 is covered and insulated by the potting agent 200, thereby suppressing copper migration. be able to. Thereby, even if there is no protective film, copper migration can be suppressed, and burning from the end of the piezoelectric element can be prevented. Moreover, in this embodiment, the whole wiring structure can be comprised with the wiring containing copper. Thereby, the manufacturing process can be further simplified, and the manufacturing cost can be reduced.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the fundamental structure of this invention is not limited to what was mentioned above.
In the first and second embodiments, the configuration in which the piezoelectric layer 70 of each active portion 310 is continuously provided has been illustrated. However, of course, the piezoelectric layer 70 is provided independently for each active portion 310. It may be done.

  Further, in Embodiments 1 and 2 described above, the piezoelectric precursor film 73 is applied, dried and degreased, and then baked to form the piezoelectric film 74. However, the present invention is not particularly limited thereto. The step of applying, drying, and degreasing the piezoelectric precursor film 73 may be repeated a plurality of times, for example, twice, and then baked to form the piezoelectric film 74.

  Also, the ink jet recording heads I and II (see FIGS. 1 and 8) are mounted on an ink jet recording apparatus III as shown in FIG. 11, for example. The recording head units 1A and 1B having the ink jet recording head I or II are detachably provided with cartridges 2A and 2B constituting ink supply means, and the carriage 3 on which the recording head units 1A and 1B are mounted is an apparatus main body. A carriage shaft 5 attached to 4 is provided so as to be movable in the axial direction. The recording head units 1A and 1B eject, for example, a black ink composition and a color ink composition.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus main body 4 is provided with a conveyance roller 8 as a conveyance means, and a recording sheet S which is a recording medium such as paper is conveyed by the conveyance roller 8. Note that the conveyance means for conveying the recording sheet S is not limited to the conveyance roller, and may be a belt, a drum, or the like.

  In the above-described example, as the ink jet recording apparatus III, the ink jet recording head I or II is mounted on the carriage 3 and moves in the main scanning direction. However, the configuration is not particularly limited. . The ink jet recording apparatus III may be, for example, a so-called line recording apparatus that performs printing by fixing the ink jet recording head I and moving a recording sheet S such as paper in the sub-scanning direction.

  In the above-described embodiments, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention is widely applied to all liquid ejecting heads, and ejects liquid other than ink. Of course, it can also be applied to the head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  Further, the piezoelectric element according to the present invention is not limited to the piezoelectric element used in the liquid ejecting head, and can be used in other devices. Other devices include, for example, an ultrasonic device such as an ultrasonic transmitter, an ultrasonic motor, a temperature-electric converter, a pressure-electric converter, a ferroelectric transistor, a piezoelectric transformer, and a filter for blocking harmful rays such as infrared rays. And filters such as an optical filter using a photonic crystal effect by quantum dot formation, an optical filter using optical interference of a thin film, and the like. The present invention can also be applied to a piezoelectric element used as a sensor and a piezoelectric element used as a ferroelectric memory. Examples of the sensor using the piezoelectric element include an infrared sensor, an ultrasonic sensor, a thermal sensor, a pressure sensor, a pyroelectric sensor, and a gyro sensor (angular velocity sensor).

  I, II Inkjet recording head (liquid ejecting head), III Inkjet recording apparatus (liquid ejecting apparatus), 10 flow path forming substrate (substrate), 11 partition, 12 pressure generating chamber, 13 ink supply path, 14 communication path, 15 communication portion, 20 nozzle plate, 21 nozzle opening, 30, 30A protective substrate, 31 sealing space, 32 manifold portion, 33 through hole, 35, 36 adhesive layer, 40 compliance substrate, 41 sealing film, 42 fixing plate, 43 opening, 50 diaphragm, 51 elastic film, 52 insulator film, 60 first electrode, 70 piezoelectric layer, 71 recess, 80 second electrode, 90 lead electrode, 91 first wiring layer, 92 first Metal layer, 93 second metal layer, 94 third metal layer, 95 second wiring layer, 100 manifold Rudo, 120 drive circuit, 200 potting agent, 201 wiring board

Claims (8)

A piezoelectric element in which a first electrode, a piezoelectric layer, and a second electrode are laminated on a flow path forming substrate, a first wiring layer configured as a wiring for the first electrode, and a sealing space for the piezoelectric element. A liquid ejecting head comprising a protective substrate to be formed and a driving circuit for driving the piezoelectric element,
The piezoelectric element is extended into a through hole provided outside the sealing space of the protective substrate,
The first wiring layer is provided on the first electrode electrically insulated from the second electrode of the piezoelectric element and connected from the piezoelectric element,
A metal layer that is insulated from the first wiring layer by an adhesive layer that joins the protective substrate between the sealing space and the through hole and the flow path forming substrate is provided on the second electrode. And
The liquid jet head, wherein the first wiring layer is covered with a potting agent filled in the through hole.   The liquid ejecting head according to claim 1, wherein the first wiring layer includes copper.   The liquid ejecting head according to claim 1, wherein the adhesive layer is made of a thermosetting epoxy resin. The side surface of the protective substrate on the outer end side of the sealing space is inclined toward the inner side of the protective substrate,
The through hole is provided with a second wiring layer connected to the first wiring layer, extending through a side surface of the protective substrate, and electrically connected to the drive circuit. The liquid ejecting head according to any one of claims 1 to 3.   The liquid ejecting head according to claim 4, wherein the second wiring layer includes gold.   The liquid according to claim 1, wherein the through hole is provided with a wiring substrate connected to the first wiring layer and electrically connected to the drive circuit. Jet head.   The liquid ejecting head according to claim 6, wherein a plating layer containing gold is provided at a portion where the first wiring layer is connected to a terminal of the wiring board.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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