JP6645173B2 - Through wiring, liquid ejecting head, method of manufacturing through wiring, method of manufacturing MEMS device, and method of manufacturing liquid ejecting head - Google Patents

Description

The present invention relates to a through wiring provided through a substrate, a liquid ejecting head having the through wiring, a method of manufacturing a through wiring, a method of manufacturing a MEMS device, and a method of manufacturing a liquid ejecting head.

  2. Description of the Related Art Some MEMS (Micro Electro Mechanical Systems) devices represented by a liquid ejecting head include a through hole provided in a substrate and a through wiring provided in the through hole.

  As such a through wiring, a through hole is formed in a substrate by etching, drilling or sandblasting, and a through wiring is formed in the through hole (for example, see Patent Document 1).

JP 2015-171803 A

  However, when the through holes are formed by laser processing from the surface of the substrate, there is a problem that burrs and debris are generated.

  In addition, due to the difference in linear expansion coefficient between the through-wiring provided in the through-hole and the substrate, a positional shift of the through-wiring with respect to the through-hole occurs due to a temperature change, and the wiring formed on the surface of the substrate due to the positional shift of the through-wiring is reduced. There is a problem of disconnection.

  In a through hole provided with a through wiring used in a MEMS device or the like, there are cases where a reduction in the size of the opening and a high density are required, and a degree of freedom of the through hole and the through wiring is desired.

  In view of such circumstances, the present invention suppresses contamination due to burrs and debris, suppresses displacement of a through-hole with respect to the through-hole, and improves the degree of freedom in forming the through-hole and the through-hole wiring, and a MEMS device. It is an object of the present invention to provide a liquid jet head, a method of manufacturing a through wiring, a method of manufacturing a MEMS device, and a method of manufacturing a liquid jet head.

  An aspect of the present invention that solves the above-mentioned problem is a through hole and a through wiring formed in the through hole, wherein the through hole includes a first recess formed at one end of the through hole, and a through hole. And a second recess formed at the other end opposite to the one end, wherein an inner wall of the first recess is inclined from the one end toward the other end with respect to a penetration direction of the through hole. And the inclination of the inner wall of the second concave portion increases from the other end toward the one end with respect to the penetrating direction of the through hole.

  In such an embodiment, the contact area between the inner wall surface of the through hole and the through wiring is increased by the first recess and the second recess, and the adhesion between the inner wall surface of the through hole and the through wiring can be improved. Further, by forming the connection portion between the first concave portion and the second concave portion into a constricted shape, it is possible to suppress displacement of the through wiring with respect to the through hole. Further, by providing the through wiring inside the first concave portion and the second concave portion, the cross-sectional area can be increased and the wiring resistance can be reduced.

  Here, the through-hole further includes a third concave portion communicating with the first concave portion, and a fourth concave portion communicating with the second concave portion, wherein the third concave portion and the fourth concave portion include the fourth concave portion. The first recess is provided between the first recess and the second recess, and the inclination of the inner wall of the first recess on the side of the third recess is greater than the inclination of the third recess on the side of the first recess. It is preferable that the inclination of the fourth concave portion on the side of the fourth concave portion is larger than the inclination of the fourth concave portion on the side of the second concave portion. According to this, the contact area between the through hole and the through wiring can be further increased by the third and fourth recesses without increasing the opening of the through hole, and the adhesion can be improved.

  Further, it is preferable that the first recess and the second recess are communicated by a communication hole. According to this, by providing the communication hole, it is possible to extend the length of the through hole in the through direction without increasing the opening of the through hole.

  Further, it is preferable that the third recess and the fourth recess are communicated by a communication hole. According to this, by providing the communication hole, it is possible to extend the length of the through hole in the through direction without increasing the opening of the through hole.

  In addition, it is preferable that each opening diameter of the first concave portion and the second concave portion is larger than a maximum diameter of the communication hole. According to this, it is possible to reduce the electric resistance value of the through wiring provided inside the first concave portion and the second concave portion, thereby reducing the wiring resistance. Further, by forming the communication hole that connects the first recess and the second recess into a constricted shape, it is possible to suppress displacement of the through wiring with respect to the through hole.

  Further, another aspect of the present invention is a MEMS device in which a signal from outside is detected and a current value changes before and after the detection, and a part of the wiring through which the current passes is the through wiring of the above aspect. The feature is in the MEMS device.

  In such an embodiment, it is possible to detect a very small current.

  Another aspect of the present invention is a liquid jet head including the through wiring of the above aspect.

  In such an embodiment, it is possible to reduce the size, reduce the wiring resistance, and drive the pressure generating means at a high frequency.

  Further, another aspect of the present invention is a method for manufacturing a through wiring formed in a through hole, wherein an inner wall at one end of the through hole is inclined toward the other end with respect to a through direction of the through hole. A first concave portion forming step of forming a first concave portion that becomes larger, a second concave portion forming step of forming a second concave portion in which the inner wall of the other end of the through hole becomes larger in inclination toward the one end, A wiring forming step of forming a through wiring in the hole, wherein the first recess forming step and the second recess forming step use a sandblast method.

  In this aspect, by forming the first concave portion and the second concave portion by the sand blast method, the inner wall of the first concave portion has a larger inclination from one end to the other end with respect to the through direction of the through hole, and The inner wall of the concave portion can be formed so that the inclination becomes larger from the other end toward one end with respect to the penetrating direction of the through hole. Further, by forming the first concave portion and the second concave portion by the sand blast method, the processing can be performed in a shorter time than the processing by the ICP. Further, by forming the first concave portion and the second concave portion by the sand blast method, it is possible to easily and densely form a through hole having a smaller opening than a laser processing in a relatively thick substrate. Further, a sandblasting apparatus that performs the sandblasting method is less expensive than a laser processing apparatus or an ICP processing etching apparatus, so that equipment investment can be reduced.

  Here, the first recess forming step includes a third recess forming step of forming a third recess communicating with the first recess, and the second recess forming step includes a fourth recess communicating with the second recess. It is preferable to include a fourth concave portion forming step of forming According to this, the inclination of the inner wall of the first concave portion on the side of the third concave portion by the sandblast method is larger than the inclination of the third concave portion on the side of the first concave portion, and the inclination of the second concave portion on the side of the fourth concave portion is the fourth. The recess can be easily formed in a shape larger than the inclination of the recess on the second recess side.

  Preferably, the method further includes a communication hole forming step of forming a communication hole connecting the first concave portion and the second concave portion. According to this, a communication hole can be formed.

  It is preferable that the method further includes a communication hole forming step of forming a communication hole connecting the third recess and the fourth recess. According to this, a communication hole can be formed.

  Preferably, the wiring forming step includes a plating method. According to this, the through wiring can be formed by the plating method.

  Still another aspect of the present invention is a method for manufacturing a MEMS device, including the method for manufacturing a through wiring according to the above-described aspect.

  In such an embodiment, through holes and through wires having small openings can be formed at a high density, and miniaturization can be achieved.

  Further, another aspect of the present invention is a method for manufacturing a liquid jet head, including the method for manufacturing a MEMS device according to the above aspect.

  In such an embodiment, through holes and through wires having small openings can be formed at a high density, and miniaturization can be achieved.

FIG. 2 is an exploded perspective view of the recording head according to the first embodiment. FIG. 2 is a plan view of the recording head according to the first embodiment. FIG. 3 is a sectional view taken along line AA ′ of FIG. 2 according to the first embodiment. FIG. 4 is an enlarged sectional view of a main part of FIG. 3 according to the first embodiment. FIG. 3 is a plan view of a main part of the flow path forming substrate according to the first embodiment. FIG. 2 is a plan view of the drive circuit board according to the first embodiment. FIG. 7 is a sectional view taken along line BB ′ of FIG. 6 according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a cross-sectional view of a main part showing a modification of the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 4 is a sectional view illustrating the method for manufacturing the recording head according to the first embodiment. FIG. 9 is a sectional view of a main part of a recording head according to a second embodiment. FIG. 9 is a sectional view illustrating the method for manufacturing the recording head according to the second embodiment. FIG. 9 is a sectional view illustrating the method for manufacturing the recording head according to the second embodiment. FIG. 13 is a cross-sectional view of a main part showing a modification of the recording head according to the second embodiment. FIG. 1 is a schematic diagram illustrating an ink jet recording apparatus according to one embodiment.

  Hereinafter, the present invention will be described in detail based on embodiments.

(Embodiment 1)
The present invention will be described in detail based on Embodiment 1. In the present embodiment, an ink jet recording head (hereinafter, simply referred to as a recording head) that discharges ink will be described as an example of a liquid ejecting head.

  FIG. 1 is an exploded perspective view of a recording head according to the present embodiment, FIG. 2 is a plan view of the recording head (a plan view on the liquid ejecting surface 20a side), and FIG. 4 is an enlarged sectional view of a main part of FIG. 3, and FIG. 5 is a plan view of a main part of the flow path forming substrate 10.

  As shown in the drawing, the recording head 1 of the present embodiment includes a plurality of members such as a flow path forming substrate 10, a communication plate 15, a nozzle plate 20, a driving circuit substrate 30, which is a wiring substrate of the present embodiment, and a compliance substrate 45. Prepare.

The channel forming substrate 10 can be made of a metal such as stainless steel or Ni, a ceramic material typified by ZrO ₂ or Al ₂ O ₃ , a glass ceramic material, an oxide such as MgO or LaAlO ₃ , or the like. In the present embodiment, the flow path forming substrate 10 is made of a silicon single crystal substrate. The flow path forming substrate 10 is anisotropically etched from one surface side so that the pressure generating chambers 12 defined by the plurality of partition walls are arranged in the direction in which the plurality of nozzle openings 21 for ejecting ink are juxtaposed. Are installed side by side. 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. The flow channel forming substrate 10 is provided with a plurality of rows in which the pressure generating chambers 12 are juxtaposed in the first direction X, in this embodiment, two rows. The direction in which the pressure generating chambers 12 are formed along the first direction X and in which a plurality of rows of the pressure generating chambers 12 are provided is hereinafter referred to as a second direction Y. Further, a direction that intersects both the first direction X and the second direction Y is referred to as a third direction Z in the present embodiment. The coordinate axes shown in each figure represent a first direction X, a second direction Y, and a third direction Z, and the direction of the arrow is also referred to as a positive (+) direction, and the opposite direction is also referred to as a negative (-) direction. . In the present embodiment, the relationship in each direction (X, Y, Z) is orthogonal, but the arrangement relationship of each component is not necessarily limited to the orthogonal relationship.

  The flow path forming substrate 10 is provided with a flow path resistance of the ink flowing into the pressure generation chamber 12 at one end side of the pressure generation chamber 12 in the second direction Y, the opening area being smaller than that of the pressure generation chamber 12. A supply path or the like may be provided.

  On one surface side of the flow path forming substrate 10 (the opposite side to the drive circuit substrate 30 and in the -Z direction), the communication plate 15 and the nozzle plate 20 are sequentially laminated. That is, a communication plate 15 provided on one surface of the flow path forming substrate 10 and a nozzle plate 20 having a nozzle opening 21 provided on the communication plate 15 on the side opposite to the flow path forming substrate 10 are provided. .

  The communication plate 15 is provided with a nozzle communication passage 16 that communicates the pressure generation chamber 12 with the nozzle opening 21. The communication plate 15 has an area larger than the flow path forming substrate 10, and the nozzle plate 20 has an area smaller than the flow path forming substrate 10. By providing the communication plate 15 in this manner, the nozzle opening 21 of the nozzle plate 20 and the pressure generation chamber 12 can be separated from each other, so that the ink in the pressure generation chamber 12 It is less susceptible to the effect of thickening due to evaporation of water. Further, since the nozzle plate 20 only needs to cover the opening of the nozzle communication passage 16 that communicates the pressure generating chamber 12 and the nozzle opening 21, the area of the nozzle plate 20 can be made relatively small, and the cost can be reduced. be able to. In the present embodiment, the surface on which the nozzle openings 21 of the nozzle plate 20 are opened and the ink droplets are ejected is referred to as a liquid ejection surface 20a.

  Further, the communication plate 15 is provided with a first manifold section 17 and a second manifold section 18 which constitute a part of the manifold 100.

  The first manifold section 17 is provided so as to penetrate the communication plate 15 in the thickness direction (the direction in which the communication plate 15 and the flow path forming substrate 10 are stacked). The second manifold portion 18 is provided so as to be open on the nozzle plate 20 side of the communication plate 15 without penetrating the communication plate 15 in the thickness direction.

  Further, a supply communication passage 19 communicating with one end of the pressure generation chamber 12 in the second direction Y is provided in the communication plate 15 independently for each pressure generation chamber 12. This supply communication passage 19 communicates the second manifold section 18 with the pressure generating chamber 12.

  As such a communication plate 15, a metal such as stainless steel or Ni, or a ceramic such as zirconium can be used. The communication plate 15 is preferably made of a material having the same linear expansion coefficient as that of the flow path forming substrate 10. That is, when a material having a significantly different linear expansion coefficient from that of the flow path forming substrate 10 is used as the communication plate 15, the material is heated or cooled, and warpage occurs due to a difference in linear expansion coefficient between the flow path forming substrate 10 and the communication plate 15. Will occur. In the present embodiment, by using the same material as the flow path forming substrate 10, that is, a silicon single crystal substrate, as the communication plate 15, it is possible to suppress occurrence of warpage due to heat, cracks due to heat, peeling, and the like.

  The nozzle plate 20 is formed with a nozzle opening 21 that communicates with each pressure generating chamber 12 via the nozzle communication passage 16. Such nozzle openings 21 are arranged side by side in the first direction X, and two rows of the nozzle openings 21 arranged side by side in the first direction X are formed in the second direction Y.

  As such a nozzle plate 20, for example, a metal such as stainless steel (SUS), an organic substance such as a polyimide resin, a silicon single crystal substrate, or the like can be used. In addition, by using a silicon single crystal substrate as the nozzle plate 20, the linear expansion coefficients of the nozzle plate 20 and the communication plate 15 are made equal, and the occurrence of warpage due to heating or cooling, cracks due to heat, and peeling are suppressed. can do.

  On the other hand, a vibration plate 50 is formed on the surface of the flow path forming substrate 10 opposite to the communication plate 15 (on the drive circuit substrate 30 side in the + Z direction). In the present embodiment, as the vibration plate 50, an elastic film 51 made of silicon oxide provided on the flow path forming substrate 10 side and an insulator film 52 made of zirconium oxide provided on the elastic film 51 are provided. I made it. The liquid flow path such as the pressure generating chamber 12 is formed by anisotropically etching the flow path forming substrate 10 from one surface side (the surface side to which the communication plate 15 is joined). The other surface of the liquid flow path is defined by an elastic film 51. Of course, the diaphragm 50 is not particularly limited to this, and one of the elastic film 51 and the insulator film 52 may be provided, and another film may be provided.

  On the vibration plate 50 of the flow path forming substrate 10, a piezoelectric actuator 300 is provided as pressure generating means for causing a pressure change in the ink in the pressure generating chamber 12 of the present embodiment. As described above, a plurality of the pressure generating chambers 12 are arranged in the flow path forming substrate 10 along the first direction X, and two rows of the pressure generating chambers 12 are arranged in the second direction Y. Have been. The piezoelectric actuators 300 are arranged side by side in the first direction X to form a piezoelectric actuator row 310, and two rows of the piezoelectric actuator rows 310 are arranged side by side in the second direction Y.

  The piezoelectric actuator 300 includes a first electrode 60, a piezoelectric layer 70, and a second electrode 80 that are sequentially stacked from the diaphragm 50 side. The first electrode 60 constituting the piezoelectric actuator 300 is divided for each pressure generating chamber 12 and constitutes an independent individual electrode for each active unit which is a substantial driving unit of the piezoelectric actuator 300. The first electrode 60 has a width smaller than the width of the pressure generation chamber 12 in the first direction X of the pressure generation chamber 12. That is, in the first direction X of the pressure generation chamber 12, the end of the first electrode 60 is located inside the region facing the pressure generation chamber 12. In the second direction Y of the pressure generating chamber 12, both ends of the first electrode 60 extend to the outside of the pressure generating chamber 12. The material of the first electrode 60 is not particularly limited as long as it is a metal material. For example, platinum (Pt), iridium (Ir), or the like is preferably used.

  The piezoelectric layer 70 is provided continuously in the first direction X such that the second direction Y has a predetermined width. The width of the piezoelectric layer 70 in the second direction Y is wider than the width of the pressure generating chamber 12 in the second direction Y. For this reason, in the second direction Y of the pressure generation chamber 12, the piezoelectric layer 70 is provided up to the outside of the pressure generation chamber 12.

  The end of the piezoelectric layer 70 at one end of the pressure generating chamber 12 in the second direction Y (the side opposite to the manifold 100) is located outside the end of the first electrode 60. That is, the end of the first electrode 60 is covered with the piezoelectric layer 70. Further, the end of the piezoelectric layer 70 at the other end of the pressure generating chamber 12 on the manifold 100 side in the second direction Y is located inside (the pressure generating chamber 12 side) the end of the first electrode 60. The end of the first electrode 60 on the manifold 100 side is not covered with the piezoelectric layer 70.

The piezoelectric layer 70 is made of a piezoelectric material of the oxide having a polarization structure formed on the first electrode 60, for example, it may consist of a perovskite-type oxide represented by the general formula ABO _3. As the perovskite-type oxide used for the piezoelectric layer 70, for example, a lead-based piezoelectric material containing lead or a lead-free piezoelectric material containing no lead can be used.

  In such a piezoelectric layer 70, concave portions 71 corresponding to each partition between the pressure generating chambers 12 are formed. The width of the recess 71 in the first direction X is substantially equal to or larger than the width of each partition in the first direction. This suppresses the rigidity of the portion of the diaphragm 50 that opposes the end of the pressure generating chamber 12 in the second direction Y (the so-called arm portion of the diaphragm 50), so that the piezoelectric actuator 300 can be displaced favorably. it can.

  The second electrode 80 is provided on the surface of the piezoelectric layer 70 opposite to the first electrode 60, and forms a common electrode common to a plurality of active portions. In addition, the second electrode 80 may or may not be provided on the inner surface of the recess 71, that is, on the side surface of the recess 71 of the piezoelectric layer 70.

  The piezoelectric actuator 300 including the first electrode 60, the piezoelectric layer 70, and the second electrode 80 is displaced by applying a voltage between the first electrode 60 and the second electrode 80. That is, when a voltage is applied between the two electrodes, piezoelectric distortion occurs 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 is referred to as an active portion. On the other hand, a portion where piezoelectric distortion does not occur in the piezoelectric layer 70 is referred to as a non-active portion.

  As described above, in the piezoelectric actuator 300, the first electrode 60 is provided independently for each of the plurality of active portions to be an individual electrode, and the second electrode 80 is provided continuously over the plurality of active portions. An electrode was used. Of course, the present invention is not limited to such an embodiment, and the first electrode 60 is provided as a common electrode by continuously providing the plurality of active portions, and the second electrode is provided as an individual electrode by providing the second electrode independently for each active portion. Is also good. Further, as the vibration plate 50, only the first electrode 60 may function as a vibration plate without providing the elastic film 51 and the insulator film 52. Further, the piezoelectric actuator 300 itself may substantially serve as the diaphragm.

  As shown in FIGS. 3, 4 and 5, from the first electrode 60 of the piezoelectric actuator 300, an individual wiring 91 which is a drawing wiring is drawn. In the present embodiment, two rows of active portions of the piezoelectric actuator 300 arranged in the first direction X are provided in the second direction Y. The individual wiring 91 is drawn out of the column in the second direction Y from the active portion of each column.

  Further, from the second electrode 80 of the piezoelectric actuator 300, a common wiring 92 which is a drawing wiring is drawn out. In the present embodiment, the common wiring 92 is electrically connected to the second electrodes 80 of the two rows of piezoelectric actuators 300. Further, the common wiring 92 is provided at a ratio of one to a plurality of active units.

  A drive circuit board 30 having substantially the same size as the flow path forming substrate 10 is joined to a surface of the flow path forming substrate 10 on the side of the piezoelectric actuator 300. The drive circuit board 30 will be described with reference to FIGS. 6 is a plan view of the drive circuit board 30 when viewed from the side of the flow path forming board, and FIG. 7 is a cross-sectional view taken along the line BB 'of FIG.

  The drive circuit board 30 is a semiconductor substrate provided with a drive circuit 120 for driving the piezoelectric actuator 300 on a surface opposite to the flow path forming substrate 10. The surface of the drive circuit board 30 facing the flow path forming substrate 10 is referred to as a first main surface 301, and the surface opposite to the flow path forming substrate 10 is referred to as a second main surface 302.

  In the present embodiment, the drive circuit 120 as an integrated circuit is formed on the second main surface 302 of the semiconductor substrate by a semiconductor manufacturing process to form the drive circuit substrate 30. Of course, the present invention is not limited to such an embodiment. For example, a drive circuit formed separately may be provided on a semiconductor substrate to form the drive circuit board 30.

  The drive circuit 120 according to the present embodiment is a circuit capable of forming a drive signal for driving the piezoelectric actuator 300 and transmitting the drive signal to the piezoelectric actuator 300, but is not limited to such an embodiment. Not done. The drive circuit 120 may be an active circuit for generating such a drive signal, or may be a circuit including only wiring for transmitting a drive signal transmitted from an external control device or the like to the piezoelectric actuator 300. Good.

  As the drive circuit board 30, it is preferable to use a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10, for example, glass, a ceramic material, or the like. In the present embodiment, silicon of the same material as the flow path forming substrate 10 is used. It was formed using a single crystal substrate.

  Further, the second main surface 302 is provided with a contact hole 37a in which a terminal of the drive circuit 120 is exposed and a first through wiring 311 and a second through wiring 312 described later are provided. The insulating film 37 covers the second main surface 302 except for the contact hole 37a. Further, as will be described later, the drive circuit board 30 is provided with a first through hole 35 and a second through hole 36 which are the through holes of the present embodiment, but the insulating film 37 is continuous from the second main surface 302. Thus, the inner surfaces of the first through hole 35 and the second through hole 36 are also covered.

  The insulating film 37 is not particularly limited as long as it is formed of a material having an insulating property. For example, silicon dioxide, silicon nitride, or the like can be used.

  The first bumps 31 and the second bumps 32 are provided on the first main surface 301 of such a drive circuit board 30. In the present embodiment, the first bump 31 and the second bump 32 are provided on the insulating film 37 covering the first main surface 301. The first bump 31 and the second bump 32 serve as contact points with the individual wiring 91 and the common wiring 92 of the flow path forming substrate 10.

  The first bump 31 and the second bump 32 include, for example, a core 33 formed of a resin material having elasticity, and a metal film 34 formed on the surface of the core 33.

  The core part 33 is formed of a photosensitive insulating resin such as a polyimide resin, an acrylic resin, a phenol resin, a silicone resin, a silicone-modified polyimide resin, an epoxy resin, or a thermosetting insulating resin.

  The core portion 33 is formed in a substantially semicylindrical shape before the drive circuit substrate 30 and the flow path forming substrate 10 are joined. Here, the term “kamaboko” refers to a columnar shape in which the inner surface (bottom surface) in contact with the drive circuit board 30 is flat and the outer surface, which is a non-contact surface, is a curved surface. Specifically, the substantially semi-cylindrical shape includes those having a substantially semicircular, substantially semi-elliptical, or substantially trapezoidal cross section.

  The core section 33 is pressed so that the drive circuit board 30 and the flow path forming board 10 are relatively close to each other, so that the tip shape follows the surface shape of the individual wiring 91 and the common wiring 92. It is deformed.

  As a result, even if the drive circuit board 30 or the flow path forming board 10 has warpage or undulation, the core portion 33 is deformed following the warp or undulation, and the first bumps 31 and the second bumps 32 and the individual wires 91 and The common wiring 92 can be reliably connected.

  In the present embodiment, the core portions 33 are arranged linearly and continuously in the first direction X. Further, in the second direction Y, a total of three core parts 33 are provided outside the two piezoelectric actuator rows 310, two core sections 33 and one between the two piezoelectric actuator rows 310. I have. Each of the core portions 33 provided outside the two rows of the piezoelectric actuator rows 310 constitutes the first bump 31 connected to the individual wiring 91 of the piezoelectric actuator row 310, and between the two rows of the piezoelectric actuator rows 310. Constitute the second bump 32 connected to the common wiring 92 of the two rows of the piezoelectric actuators 310.

  Such a core portion 33 can be formed by a photolithography technique or an etching technique.

  The metal film 34 covers the surface of the core 33. The metal film 34 is formed of a metal or alloy such as Au, TiW, Cu, Cr (chromium), Ni, Ti, W, NiV, Al, Pd (palladium), and lead-free solder. Or a laminate of a plurality of types. The metal film 34 is deformed following the surface shape of the individual wiring 91 and the common wiring 92 due to the elastic deformation of the core 33, and is metal-joined to the individual wiring 91 and the common wiring 92.

  The metal film 34 connected to the individual wiring 91 is provided on the surface of the core 33 at the same pitch as the individual wiring 91 in the first direction X. Further, the metal film 34 connected to the common wiring 92 extends in the first direction X so as to cover the entire surface of the core portion 33. In the present embodiment, a plurality of common wirings 92 are formed, but the metal film 34 is formed so as to contact all of them in common.

  The metal film 34 provided on the surface of the core portion 33 constituting the first bump 31 and the second bump 32 and the individual wiring 91 and the common wiring 92 are joined at room temperature. Specifically, the drive circuit board 30 and the flow path forming board 10 of the present embodiment are joined by the adhesive layer 39, so that the first bumps 31 and the second bumps 32, the individual wirings 91 and the common wirings 92 are formed. Are fixed in contact with each other.

  Here, the adhesive layer 39 is formed of, for example, an adhesive such as an epoxy resin, an acrylic resin, or a silicone resin. In particular, by using a photosensitive resin used for a photoresist or the like, the adhesive layer can be easily and accurately formed.

  In the present embodiment, the adhesive layers 39 are provided on both sides of the first bump 31 and both sides of the second bump 32, that is, on both sides of the first bump 31 and the second bump 32 in the second direction Y. ing. Since three first bumps 31 and second bumps 32 extending in the first direction X are provided in the second direction Y, the adhesive layer 39 extending in the first direction X Six are provided in the second direction Y. The adhesive layers 39 arranged in parallel in the second direction Y are provided so that the ends are continuous at both ends in the first direction X. That is, the adhesive layer 39 is formed so as to surround each row of the piezoelectric actuator rows 310 so as to have a rectangular frame shape when viewed in plan.

  As described above, the space between the flow path forming substrate 10 and the drive circuit board 30 is a space in which the piezoelectric actuator 300 is disposed by the adhesive layer 39 that joins the flow path forming substrate 10 and the drive circuit board 30. A holding section 320 is formed. In the present embodiment, since the adhesive layer 39 is provided continuously around each row of the piezoelectric actuator row 310, the piezoelectric actuator row 310 is provided between the flow path forming substrate 10 and the drive circuit board 30. The holding unit 320 is provided independently for each case.

  The holding section 320 may be a sealed space that is isolated from the outside, or may be a non-sealed space that is partially connected to the outside.

  The drive circuit board 30 is provided with a first through-hole 35 and a second through-hole 36, which are the through-holes of the present embodiment that communicate the first main surface 301 and the second main surface 302.

  The first through hole 35 has a first concave portion 351 provided on the first main surface 301 which is one end of the first through hole 35 and a second concave surface 351 provided on the other end of the first through hole 35. And a second concave portion 352 provided.

  The inner wall of the first concave portion 351 is inclined from one end to the other end, that is, from the first main surface 301 to the second main surface 302, with respect to the third direction Z that is the through direction of the first through hole 35. It is formed to be large. That is, the first concave portion 351 is provided such that the inner wall has a so-called concave curved surface such that the opening area on the first main surface 301 side is large and the opening area is gradually reduced toward the second main surface 302. ing.

  Further, the inner wall of the second concave portion 352 extends from the other end to one end, that is, from the second main surface 302 to the first main surface 301 with respect to the third direction Z which is the through direction of the first through hole 35. It is formed so that the inclination becomes large. That is, the second concave portion 352 is provided such that the inner wall has a so-called concave curved surface such that the opening area on the second main surface 302 side is large and the opening area gradually decreases toward the first main surface 301. ing. Then, the bottom surfaces of the first concave portion 351 and the second concave portion 352 communicate with each other, so that the first through hole 35 is formed. That is, the portion where the first concave portion 351 and the second concave portion 352 communicate has the narrowest opening and a narrow shape.

  Such a first through hole 35 is provided for each first electrode 60 that is an individual electrode. That is, as described above, in the first electrode 60, two rows of the plurality of first electrodes 60 along the first direction X are provided in the second direction Y. For this reason, in the first through-holes 35, two rows arranged in the first direction X are provided in the second direction Y, corresponding to the first electrodes 60.

  The second through hole 36 has a first concave portion 361 and a second concave portion 362 similarly to the first through hole 35. That is, the first concave portion 361 and the second concave portion 362 of the second through hole 36 have the same shape as the first concave portion 351 and the second concave portion 352 of the first through hole 35, respectively.

  At least one such second through hole 36 is provided corresponding to the second electrode 80 which is a common electrode. In the present embodiment, two second through holes 36 are provided outside the second bumps 32 in the first direction X in a plan view of the drive circuit board 30 from the third direction Z.

  In the first through-hole 35 and the second through-hole 36, a first through-wire 311 and a second through-wire 312 are formed as through wires, respectively. The first through wiring 311 and the second through wiring 312 are filled inside the first through hole 35 and the second through hole 36. One end of each of the first through wiring 311 and the second through wiring 312 is connected to a terminal of the drive circuit 120 on the second main surface 302 side of the drive circuit board 30. That is, the first through wiring 311 and the second through wiring 312 extend continuously from the first through hole 35 and the second through hole 36 to the second main surface 302 (insulating film 37), and further, the contact hole It extends to the inside of 37 a and is connected to the terminal of the drive circuit 120.

  The method for manufacturing the first through-hole 35 and the second through-hole 36 and the first and second through-wirings 311 and 312 will be described later in detail.

  As described above, since the first through-hole 35 has a narrowed inner diameter at a portion where the first recessed portion 351 and the second recessed portion 352 communicate with each other, the first through-hole 35 is formed in the first through-hole 35. The movement of the one through wiring 311 in the third direction Z, which is the penetrating direction of the first through hole 35, is restricted by the constricted shape, and the one through wiring 311 is unlikely to be displaced. Therefore, when a temperature change occurs, the first through-wiring 311 is positioned in the third direction Z with respect to the first through-hole 35 due to a difference in linear expansion coefficient between the drive circuit board 30 and the first through-wiring 311. It is possible to suppress the occurrence of the displacement and the protrusion from the first main surface 301 or the second main surface 302 of the drive circuit board 30. Incidentally, when the first through wiring 311 is displaced in the third direction Z of the first through hole 35 and jumps out of the first main surface 301 or the second main surface 302 of the drive circuit board 30, the drive circuit board The wiring formed on the surface of the first through wiring 30, for example, a part of the first through wiring 311 extending on the second main surface 302, or the metal film 34 connected to the first through wiring 311 on the first main surface 301. May be disconnected. In the present embodiment, since the displacement of the first through wiring 311 with respect to the first through hole 35 is suppressed, disconnection of the wiring formed on the surface of the drive circuit board 30 can be suppressed. Similarly, the second through-hole 36 and the second through-hole 312 provided in the second through-hole 36 are also separated by the second through-hole 36 into the third through-hole 36 of the second through-hole 312. Displacement in the direction Z can be suppressed, and disconnection of the wiring can be suppressed.

  In addition, by providing the first recess 351 and the second recess 352 in the first through hole 35, the first through hole 35 is formed in the first through hole 35 in the third direction Z that is the through direction. The area of the inner wall surface to which the through wiring 311 adheres can be increased. Therefore, the adhesion between the first through-wiring 311 and the inner wall of the first through-hole 35 can be improved, and the displacement of the first through-wiring 311 with respect to the first through-hole 35 can be suppressed.

  Further, the first through-wire 311 formed in the first through-hole 35 and the second through-wire 312 formed in the second through-hole 36 are formed by the opening of the first main surface 301 of the first recesses 351 and 361. The second concave portions 352 and 362 are provided so that the openings of the second main surface 302 are large. For this reason, the electric resistance of the first through wiring 311 and the second through wiring 312 in the first through hole 35 and the second through hole 36 can be reduced, and the wiring resistance is reduced when the piezoelectric actuator 300 is driven at a high frequency. Can be suppressed. Incidentally, the first through hole 35 is not provided with the first concave portion 351 and the second concave portion 352, and the first opening 351 and the second concave portion 352 have the narrowest opening area and the third direction which is the through direction. When the first through hole 35 is provided over Z, the electric resistance value of the first through wiring 311 is higher than in the present embodiment, so that when the piezoelectric actuator 300 is driven at a high frequency, the signal delay due to the wiring resistance is reduced. This may cause print quality to deteriorate.

  Further, on the first main surface 301 of the drive circuit board 30, the metal films 34 of the first bumps 31 and the second bumps 32 extend toward the center in the second direction Y. The other ends of the first through wirings 311 and the second through wirings 312 are connected to portions of the first bump 31 and the second bumps 32 on which the metal film 34 extends on the first main surface 301 side of the drive circuit board 30. are doing. That is, the first bumps 31 and the second bumps 32 are electrically connected to the drive circuit 120 by the first through wirings 311 and the second through wirings 312.

  The first through wiring 311, the second through wiring 312, and the drive circuit 120 are provided with a protective film 340 that protects them. In the present embodiment, the protective film 340 is provided to protect the drive circuit 120 from moisture, has a property that is hardly deteriorated by moisture (moisture), and transmits (transmits) moisture (moisture). (Wet).

The protective film 340 is not particularly limited as long as the material has moisture resistance. For example, silicon nitride (SiN), silicon oxide (SiOx), tantalum oxide _(TaO x), an inorganic insulating material such as aluminum oxide (AlO _x), polyimide (PI) and polyvinylidene fluoride (PVdF), and fluorine-based resin Materials can be used. Further, the number of the protective films 340 is not limited to one, and may be a plurality of layers. In this case, a plurality of protective films 340 may be formed using the same material, or a plurality of protective films 340 may be formed using different materials.

  Although details will be described later, the first through wiring 311 and the second through wiring 312 can be formed by a plating method. By forming the first through wiring 311 and the second through wiring 312 by plating, the first through wiring 311 and the second through wiring 312 are formed in the first through hole 35 and the second through hole 36 which are fine openings. It can be formed so as to be filled.

  Note that the first through wiring 311 and the second through wiring 312 are not limited to a mode in which the first through hole 35 and the second through hole 36 are filled. For example, a metal film formed by a vapor phase method such as a sputtering method only on the inner surfaces of the first through hole 35 and the second through hole 36 may be used as the first through wiring 311 and the second through wiring 312.

  The first through wiring 311 and the second through wiring 312 are connected to the first electrode 60 and the second electrode 80 via the first bump 31 and the second bump 32. Specifically, the individual wiring 91 connected to each first electrode 60 and the first through wiring 311 are electrically connected by the first bump 31. Further, the common wiring 92 connected to the second electrode 80 and the second through wiring 312 are electrically connected by the second bump 32.

  Note that the first through wiring 311 and the second through wiring 312 may be directly connected to the first electrode 60 and the second electrode 80 without using the individual wiring 91 and the common wiring 92.

  As described above, in the recording head 1 according to the present embodiment, the piezoelectric actuator 300 is housed in the holding unit 320, and the drive circuit 120 is provided on the second main surface 302 side of the drive circuit board 30. The drive circuit 120 has a so-called face-up arrangement facing the side opposite to the piezoelectric actuator 300. The piezoelectric actuator 300 and the drive circuit 120 are electrically connected to each other by a first through wire 311 and a second through wire 312 that penetrate the drive circuit board 30 and extend in the third direction Z.

  If the drive circuit 120 is arranged face-down, as described in the related art, wiring from an external control circuit or the like is provided on the first main surface 301 side of the drive circuit board 30 outside the holding section 320. Must be provided with an input section to which is connected. That is, the drive circuit board 30 becomes large in a horizontal plane (a plane defined by the first direction X and the second direction Y).

  However, the recording head 1 of the present embodiment requires a region for providing an input section to which an external wiring from an external control circuit or the like is connected in the drive circuit 120 by arranging the drive circuit 120 in a face-up arrangement. do not do. Therefore, an area for forming such an input section is not required for the drive circuit board 30, and the drive circuit board 30 can be downsized.

  Further, in the recording head 1 according to the present embodiment, the first through wiring 311 and the second through wiring 312 extend in the third direction Z penetrating the drive circuit board 30. Accordingly, even if the piezoelectric actuator 300 and the drive circuit 120 are separated from each other inside and outside the holding section 320 by arranging the drive circuit 120 in a face-up arrangement, they can be electrically connected.

  Here, if wiring for connecting the piezoelectric actuator 300 and the drive circuit 120 is provided without penetrating the drive circuit board 30, the following mode is provided. First, the individual wiring 91 and the common wiring 92 are extended to the outside of the holding unit 320 in the first direction X or the second direction Y. Then, the extended individual wires 91 and the common wires 92 are connected to the drive circuit 120 by wires such as bonding wires. In such an embodiment, a region for drawing out the individual wiring 91 and the common wiring 92 to the outside of the holding unit 320 is required, and the recording head 1 is positioned on a horizontal plane (a plane defined by the first direction X and the second direction Y). It becomes large.

  However, in the recording head 1 according to the present embodiment, since the first through wirings 311 and the second through wirings 312 extend in the third direction Z that penetrates the drive circuit board 30, the size of the print head 1 on a horizontal plane may be increased. Can be avoided. In the present embodiment, the first through-holes 35 and the second through-holes 36 having relatively fine openings can be arranged at a high density, so that the size of the recording head 1 in the horizontal direction can be reduced. be able to.

  As described above, the recording head 1 according to the present embodiment can be downsized on a horizontal plane. Since the recording head 1 can be reduced in size, the recording head 1 can cope with a high density of the nozzle openings 21 and can discharge ink at a high density.

  In addition, between the two rows of piezoelectric actuators 310, a common wiring 92 extending from the second electrode 80, which is a common electrode, is provided. That is, the second electrodes 80 of the two piezoelectric actuator rows 310 are integrated. Therefore, the second bumps 32 connected to the second bumps 32 may be arranged in a single row. As a result, a total of three bumps in total, including the first bump 31 and the second bump 32, can be used, and the width of the drive circuit board 30 in the second direction Y can be reduced.

  If the individual wires 91 extending from the first electrodes 60, which are the individual electrodes, are provided between the two rows of the piezoelectric actuators 310, the individual wires 91 cannot be integrated. Therefore, two rows of the first bumps 31 corresponding to each of the piezoelectric actuator rows 310 must be arranged between the two rows of the piezoelectric actuator rows 310. Then, outside the two rows of the piezoelectric actuator rows 310, two rows of the second bumps 32 must be arranged corresponding to the respective second electrodes 80. As a result, four first bumps 31 and second bumps 32 are required, and the width of the drive circuit board 30 in the second direction Y is increased.

  Further, the second bumps 32 are provided between the two rows of piezoelectric actuators 310. That is, the second bump 32 is formed to have a length equal to or less than the length of the piezoelectric actuator row 310 in the first direction X. Accordingly, the length of the second bump 32 in the first direction X can be made shorter than the case where the second bump 32 is provided in a region other than between the piezoelectric actuator rows 310, and the second bump 32 is provided. Also, the size of the driving circuit board 30 can be reduced in the first direction X.

  In the recording head 1 according to the embodiment, the adhesive layers 39 are provided on both sides of the first bump 31 and the second bump 32 in the second direction Y. With such a configuration, the electrical connection between the first bump 31 and the second bump 32 and the individual wiring 91 and the common wiring 92 can be more reliably maintained.

  Further, as described above, the metal film 34 forming the second bump 32 is formed so as to be in common contact with all of the plurality of common wirings 92. Since the second bump 32 including the metal film 34 is used, at least one second through hole 36 for connecting the metal film 34 to the driving circuit 120 and the second through wiring 312 formed therein are provided. It may be formed. Thereby, the area where the second through hole 36 is provided in the drive circuit board 30 can be minimized, and the drive circuit board 30 can be downsized.

  In the drive circuit board 30, the second through holes 36 and the second through wires 312 are provided on both sides of the second bump 32 in the first direction X. Thereby, the difference in the distance from each common wiring 92 to the drive circuit 120 is reduced, and the variation in voltage drop can be suppressed. Thus, it is possible to prevent the ink ejection characteristics of the piezoelectric actuator 300 from being varied.

  Thus, in order to suppress the variation in the voltage drop, it is sufficient to provide the plurality of second through holes 36 and the second through wirings 312. However, as described above, these are formed on the drive circuit board 30. This requires an area to perform. In the present embodiment, the two second through holes 36 and the second through wires 312 are arranged on both sides of the second bump 32 in the first direction X. That is, the area in which the second through-hole 36 and the second through-wiring 312 are provided is limited to the outside of the second bump 32 in the first direction X. Thus, the variation of the voltage drop can be suppressed by the two second through holes 36 and the second through wirings 312, and the drive circuit board 30 can be downsized in the second direction Y.

  In addition, as shown in FIG. 4, the adhesive layer 39 that joins the flow path forming substrate 10 and the drive circuit substrate 30 is connected to the first bump 31 in the connection direction of the first bump 31, that is, in the third direction Z. Some overlap. Specifically, the width of the adhesive layer 39 in the second direction Y is widened so as not to hinder the connection between the first bump 31 and the individual wiring 91 on the flow path forming substrate 10 side. That is, in the present embodiment, the cross section of the adhesive layer 39 in the second direction Y has a trapezoidal shape in which the flow path forming substrate 10 is wider and the drive circuit substrate 30 is narrower. . By overlapping the adhesive layer 39 and the first bump 31 in the third direction Z in this manner, the bonding area of the adhesive layer 39 is increased, and the bonding strength between the flow path forming substrate 10 and the drive circuit substrate 30 is increased. Can be improved. Further, in the present embodiment, the bonding area of the bonding layer 39 is expanded toward the first bump 31 so as not to hinder the connection between the first bump 31 and the individual wiring 91. Can be reduced in size as compared with the case where it is spread on the opposite side. Although not particularly shown, the bonding layer 39 of the common wiring 92 has the same configuration, so that the bonding strength between the flow path forming substrate 10 and the driving circuit substrate 30 can be further improved.

  As shown in FIGS. 1 to 3, a manifold 100 communicating with the plurality of pressure generating chambers 12 is formed on the joined body of the flow path forming substrate 10, the drive circuit substrate 30, the communication plate 15, and the nozzle plate 20. The case member 40 is fixed. The case member 40 has substantially the same shape as the communication plate 15 described above in a plan view, and is joined to the drive circuit board 30 and also to the communication plate 15 described above. More specifically, the case member 40 has a concave portion 41 on the side of the drive circuit board 30 having a depth to accommodate the flow path forming board 10 and the drive circuit board 30. The concave portion 41 has an opening area larger than the surface of the drive circuit substrate 30 joined to the flow path forming substrate 10. The opening surface of the concave portion 41 on the nozzle plate 20 side is sealed by the communication plate 15 in a state where the flow path forming substrate 10 and the like are accommodated in the concave portion 41. The case member 40 has a third manifold portion 42 having a concave shape on both sides of the concave portion 41 in the second direction Y. The third manifold section 42, the first manifold section 17 and the second manifold section 18 provided on the communication plate 15 constitute the manifold 100 of the present embodiment.

  As a material of the case member 40, for example, a resin, a metal, or the like can be used. Incidentally, by molding a resin material as the case member 40, mass production can be performed at low cost.

  A compliance board 45 is provided on a surface of the communication plate 15 on the nozzle plate 20 side. The compliance substrate 45 seals the openings on the nozzle plate 20 side of the first manifold section 17 and the second manifold section 18. In the present embodiment, such a compliance substrate 45 includes a sealing film 46 and a fixed substrate 47. The sealing film 46 is formed of a flexible thin film (for example, a thin film formed of polyphenylene sulfide (PPS) or stainless steel (SUS) and having a thickness of 20 μm or less), and the fixed substrate 47 is formed of stainless steel ( It is formed of a hard material such as a metal such as SUS). Since a region of the fixed substrate 47 facing the manifold 100 is an opening 48 completely removed in the thickness direction, one surface of the manifold 100 is sealed only with the sealing film 46 having flexibility. The compliance part 49 is a flexible part.

  The case member 40 is provided with an introduction path 44 that communicates with the manifold 100 and supplies ink to each of the manifolds 100. Further, the case member 40 is provided with a connection port 43 through which the drive circuit board 30 is exposed and an external wiring (not shown) is inserted. The external wiring inserted into the connection port 43 is connected to the drive circuit 120. It is connected.

  In the recording head 1 having such a configuration, when ejecting the ink, the ink is taken in from the liquid storage means in which the ink is stored via the introduction path 44, and the inside of the flow path is extended from the manifold 100 to the nozzle opening 21. Fill with. Thereafter, a voltage is applied to each of the piezoelectric actuators 300 corresponding to the pressure generating chambers 12 in accordance with a signal from the drive circuit 120, so that the diaphragm 50 is flexibly deformed together with the piezoelectric actuators 300. As a result, the pressure in the pressure generating chamber 12 increases, and ink droplets are ejected from a predetermined nozzle opening 21.

  Here, a method for manufacturing the recording head according to the present embodiment will be described with reference to FIGS. 8 to 27 are cross-sectional views illustrating a method for manufacturing a recording head according to the embodiment.

  First, a method for manufacturing the drive circuit board 30 which is the wiring board of the present embodiment will be described. In the present embodiment, a plurality of drive circuit boards 30 are integrally formed on a drive circuit board wafer 130 which is a silicon wafer.

  Specifically, as shown in FIG. 8, a first insulating film 401 made of silicon dioxide is formed by thermally oxidizing a wafer 130 for a driving circuit substrate, and a driving circuit 120 is formed on one surface (second main surface 302). Are integrally formed.

  Next, as shown in FIG. 9, a portion of the first insulating film 401 that will become the first through hole 35 is removed. Specifically, a resist layer 410 is provided on the first main surface 301 and the second main surface 302 of the driving circuit substrate wafer 130, and is exposed in a predetermined shape so as to remove a portion to be the first through hole 35. . Although not particularly shown, the second through hole 36 is formed similarly. Then, portions of the first insulating film 401 to be the first through holes 35 and the second through holes 36 are removed by dry etching. After that, the remaining resist layer 410 is removed.

  Next, as shown in FIG. 10, both sides of the driving circuit board wafer 130, that is, the first through hole 35 and the second through hole 36 on the first main surface 301 and the second main surface 302, respectively. A resist layer 411 having an opening is formed. The resist layer 411 can be formed in a predetermined shape by a photolithography method using a photosensitive resist such as a dry film. In the present embodiment, the resist layer 410 and the resist layer 411 are separately formed. However, the present invention is not limited to this. The resist layer 411 is used instead of the resist layer 411 without providing the resist layer 411. You may do so. That is, the resist layer 410 may be used in the next step without being removed.

  Next, as shown in FIG. 11, the drive circuit board wafer 130 is subjected to sand blasting from both surfaces of the first main surface 301 and the second main surface 302 via the resist layer 411 to thereby form the first concave portion 351. Then, the first through hole 35 having the second concave portion 352 is formed. That is, the first concave portion 351 is formed by performing the sand blast method from the first main surface 301 of the driving circuit substrate wafer 130 (first concave portion forming step). Further, the second concave portion 352 is formed by performing the sandblasting method from the second main surface 302 of the driving circuit substrate wafer 130 (second concave portion forming step). In the present embodiment, the first concave portion 351 and the second concave portion forming step can form the first through hole 35 in which the first concave portion 351 and the second concave portion 352 communicate with each other on the bottom surface. The order of the first concave portion forming step and the second concave portion forming step is not particularly limited. Further, in the sandblasting method of the driving circuit substrate wafer 130 which is a silicon wafer, for example, silicon carbide (SiC) or the like can be used as an abrasive. Of course, the abrasive used in the sandblasting method is not limited to silicon carbide, and aluminum oxide or glass may be used. After forming the first through holes 35 and the second through holes 36 in this manner, the remaining resist layer 411 is removed.

  By forming the first concave portion 351 and the second concave portion 352 by the sand blast method in this manner, the inner wall of the first concave portion 351 moves from the first main surface 301 to the second main surface 302 in the third direction Z. A so-called concave surface can be formed so as to increase the inclination. Further, the inner wall of the second concave portion 352 can be formed as a so-called concave curved surface such that the inclination increases in the third direction Z from the second main surface 302 toward the first main surface 301.

  On the other hand, when the first through hole 35 is formed by laser processing, ICP (Inductively Coupled Plasma) processing, etching, or drilling, the general shape is straight over the third direction Z which is the through direction. Formed in various shapes

  Incidentally, when the first through hole 35 having the first concave portion 351 and the second concave portion 352 is formed by sandblasting as in the present embodiment, for example, the first concave portion 351 and the first concave portion 351 are formed in the drive circuit board 30 having a thickness of 300 μm or more. The opening diameter of the second concave portion 352 in the first main surface 301 and the second main surface 302 can be formed at a density of about 300 dpi with an opening diameter of 80 μm or less.

  Although not particularly shown, when forming the first through hole 35, the second through hole 36 is formed in the driving circuit board wafer 130 at the same time. That is, the first concave portion 351 of the first through hole 35 and the first concave portion 361 of the second through hole 36 can be simultaneously formed by the sandblast method via the resist layer 411 which is the same mask. In addition, the second concave portion 352 of the first through hole 35 and the second concave portion 362 of the second through hole 36 can be simultaneously formed by the sandblast method via the resist layer 411 which is the same mask. Thereby, the number of steps can be reduced and the cost can be reduced.

  Next, as shown in FIG. 12, a second insulating film 402 is formed on the drive circuit board wafer 130. Specifically, a second insulating film 402 made of, for example, silicon dioxide is formed on the entire surface of the drive circuit board wafer 130 by the CVD method. Thus, the inner surface of the first through hole 35 of the drive circuit board wafer 130 which is a silicon wafer is insulated by the second insulating film 402. Although not particularly shown, the inner surface of the second through hole 36 is also insulated by the second insulating film 402.

  Next, as shown in FIG. 13, a first through-wiring 311a constituting a part of the first through-wiring 311 is formed in the first through-hole 35 (wiring forming step). Here, the first through wiring 311 containing copper is formed.

  Specifically, a seed layer made of copper is formed in the first through hole 35 by a CVD method or a sputtering method. This seed layer functions as a catalyst (activator) for the subsequent electroless plating. Next, a first through wiring 311 made of copper is formed on the seed layer by electroless plating. Thus, the first through wiring 311a made of copper filled in the first through hole 35 is formed. Although not particularly shown, a part of the second through wiring 312 made of copper is similarly formed in the second through hole 36 in the same manner. After that, it is preferable that both surfaces of the drive circuit board wafer 130 are subjected to chemical mechanical polishing (CMP).

  Here, as described above, the first recesses 351 and 361 and the second recesses 352 and 362 forming the first through-hole 35 and the second through-hole 36 are formed in the third direction Z whose inner wall surface is in the through-direction. , That is, the inner wall surface is arranged toward the surface. Therefore, when the seed layer, the first through wiring 311 and the second through wiring 312 are formed in the first recesses 351 and 361 and the second through holes 352 and 362, the seed layer, the first through wiring 311 and the second through wiring 311 are formed. The wiring 312 can be relatively easily formed by improving the surroundings of the first through hole 35 and the second through hole 36 on the inner wall surface. Incidentally, when the inner wall surfaces of the first through hole 35 and the second through hole 36 are provided linearly along the third direction Z, that is, straight, the first through hole 35 and the second through hole 36 are provided. There is a possibility that the periphery of the seed layer, the first through wiring 311 and the second through wiring 312 on the inner wall surface of the semiconductor device may be reduced, and defective formation or peeling of the seed layer, the first through wiring 311 and the second through wiring 312 may occur. is there. In the present embodiment, it is possible to improve formation of the seed layer and the first through wiring 311 and the second through wiring 312 in the first through hole 35 and the second through hole 36 so as to suppress formation defects and peeling. it can.

  Next, as shown in FIG. 14, the terminal portion of the drive circuit 120 is exposed. Specifically, a resist layer 412 is formed on the second main surface 302 side of the drive circuit substrate wafer 130 so that the terminals of the drive circuit 120 are exposed. Then, by performing dry etching, a part of the second insulating film 402 on the second main surface 302 is removed to form a contact hole 37a, and the terminal of the drive circuit 120 is exposed. After that, the resist layer 412 is removed.

  Next, as shown in FIG. 15, a first through wiring 311b constituting a part of the first through wiring 311 is formed on the second main surface 302 side of the drive circuit board wafer 130. Specifically, an adhesion layer (not particularly shown) is formed on the entire surface of the second main surface 302 of the driving circuit substrate wafer 130, and a wiring layer 413 made of gold is formed on the adhesion layer. When gold or copper is used for the wiring layer 413, nickel, an alloy of nickel and chromium (nichrome), titanium tungsten, or the like can be used as the adhesion layer.

  Next, as shown in FIG. 16, the first through wiring 311 including the first through wiring 311a and the first through wiring 311b is formed by patterning the wiring layer 413. Note that the wiring layer 413 can be patterned by, for example, forming a resist of a predetermined shape on the wiring layer 413 and etching the resist through the resist. As another manufacturing method of the first through wiring 311, laser patterning using laser light may be performed. According to the laser patterning, highly accurate patterning becomes possible. Although not particularly shown, the second through wiring 312 is formed in the same manner.

  Next, as shown in FIG. 17, a protective film 340 is formed so as to cover the second main surface 302 of the drive circuit board wafer 130, that is, the second insulating film 402 and the first through wiring 311. Here, polyimide is used for the protective film 340. The method for forming the protective film 340 is not particularly limited, and examples thereof include a CVD method, a spin coating method, and a sputtering method.

  Next, as shown in FIG. 18, the first bump 31 and the second bump 32 are formed. Specifically, a resin such as a photosensitive insulating resin or a thermosetting insulating resin such as a polyimide resin, an acrylic resin, a phenol resin, a silicone resin, a silicone-modified polyimide resin, or an epoxy resin is applied to the first main surface 301 side, The core portion 33 is formed by patterning into a predetermined shape. Next, a metal film 34 is formed on the core part 33. Specifically, an adhesion layer (not shown) is formed by a sputtering method, and a wiring layer (particularly not shown) made of gold is formed on the adhesion layer. Then, the first bump 31 and the second bump 32 are formed by patterning the adhesion layer and the wiring layer into a predetermined shape by photolithography.

  The arrangement of the second bumps 32 on the flow path forming substrate 10 is not particularly limited, but is equal to or less than the length between the two rows of the piezoelectric actuator rows 310, that is, the length in the first direction X of the piezoelectric actuator rows 310. Now, it is preferable to form the second bump 32. Accordingly, the length of the second bump 32 in the first direction X can be made shorter than the case where the second bump 32 is provided in a region other than between the piezoelectric actuator rows 310, and the second bump 32 is provided. Also, the size of the driving circuit board 30 can be reduced in the first direction X.

  The second bump 32 may be formed in a region on an extension of the piezoelectric actuator row 310. That is, in the first direction X, the second bump 32 is provided in a region outside the piezoelectric actuator row 310, and the common wiring 92 is extended from the second electrode 80, which is a common electrode, to a position facing the second bump 32. It may be provided.

  The above is the method of manufacturing the drive circuit board 30 which is the wiring board of the present embodiment.

  Next, as shown in FIG. 19, the vibration plate 50 is formed on the surface of the wafer 110 for a flow path forming substrate, which is a silicon wafer and on which the plurality of flow path forming substrates 10 are integrally formed. In the present embodiment, silicon dioxide (elastic film 51) formed by thermally oxidizing wafer 110 for a passage-forming substrate, and zirconium oxide (insulator film 52) formed by thermal oxidation after being formed by a sputtering method. ) Was formed.

  Next, as shown in FIG. 20, a first electrode 60 is formed on the entire surface of the diaphragm 50 and is patterned into a predetermined shape. Note that a control layer for controlling the crystal growth of the piezoelectric layer 70 may be formed on the first electrode 60. In the present embodiment, although not particularly shown, titanium is used for controlling the crystal of the piezoelectric layer 70 (PZT). Since titanium is taken into the piezoelectric layer 70 when the piezoelectric layer 70 is formed, it does not exist as a film after the piezoelectric layer 70 is formed.

  Next, as shown in FIG. 21, a piezoelectric layer 70 and a second electrode 80 are sequentially formed on the first electrode 60. Here, in the present embodiment, a so-called sol-gel obtained by dissolving and dispersing a metal complex in a solvent is applied and dried to form a gel, and then fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed by using the method. Note that the method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, but may be, for example, a MOD (Metal-Organic Decomposition) method, a PVD (Physical Vapor Deposition) method such as a sputtering method or a laser ablation method, or the like. Is also good. That is, the piezoelectric layer 70 may be formed by any of a liquid phase method and a gas phase method.

  Next, as shown in FIG. 22, the piezoelectric actuator 300 is formed by simultaneously patterning the piezoelectric layer 70 and the second electrode 80. The patterning of the piezoelectric layer 70 and the second electrode 80 includes, for example, dry etching such as reactive ion etching and ion milling.

  Next, as shown in FIG. 23, an individual wiring 91 and a common wiring 92 made of gold (Au) are formed and patterned into a predetermined shape.

  After the individual wiring 91 and the common wiring 92 are formed in this way, as shown in FIG. 24, the drive circuit board wafer 130 manufactured by the above-described process is placed on the piezoelectric actuator 300 side of the flow path formation board wafer 110. The bonding is performed via the adhesive layer 39. Thereby, the individual wiring 91 and the common wiring 92 are connected to the first through wiring 311 and the second through wiring 312 via the first bump 31 and the second bump 32. Note that the first insulating film 401 and the second insulating film 402 are integrally illustrated as the insulating film 37.

  Next, as shown in FIG. 25, the flow path forming substrate wafer 110 to which the driving circuit substrate wafer 130 is bonded is thinned to a predetermined thickness.

  Next, as shown in FIG. 26, a mask film 53 is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape.

  Next, as shown in FIG. 27, the pressure generation chamber corresponding to the piezoelectric actuator 300 is formed by performing anisotropic etching (wet etching) on the flow path forming substrate wafer 110 through the mask film 53 using an alkaline aqueous solution. 12 is formed.

  Thereafter, the joined body in which the wafer 110 for the flow path forming substrate and the wafer 130 for the driving circuit board are bonded together becomes the chip forming flow path forming substrate 10 and the driving circuit substrate 30 as shown in FIG. After that, the communication plate 15 in which the nozzle communication passages 16 and the like are formed on the surface of the flow path forming substrate 10 opposite to the drive circuit substrate 30, the nozzle plate 20 in which the nozzle openings 21 are formed, the compliance substrate 45 are sequentially joined. The recording head 1 of the present embodiment is obtained by joining the case member 40 to the drive circuit board 30 and the communication plate 15.

  In the manufacturing method of the recording head 1 according to the embodiment described above, the drive circuit is provided by extending the first through wiring 311 and the second through wiring 312 in the third direction Z that is the through direction of the drive circuit board 30. It is possible to avoid increasing the size of the substrate 30 in a horizontal direction, that is, a plane direction including the first direction X and the second direction Y.

  Further, the first recesses 351 and 361 and the second recesses 352 and 362 forming the first through hole 35 and the second through hole 36 in which the first through wiring 311 and the second through wiring 312 are provided are formed by sandblasting. The first through-hole 35 and the second through-hole 36 can be formed at a high density with a relatively small opening area. Therefore, the drive circuit board 30 can be downsized in the horizontal direction, and the printhead 1 can be downsized.

  Further, the first recesses 351 and 361 and the second recesses 352 and 362 that constitute the first through holes 35 and the second through holes 36 are formed by sandblasting, so that the first through holes 35 and the second through holes 36 are formed. Processing speed can be increased and processing can be performed in a short time as compared with the case of forming by ICP. Incidentally, when a through-hole is formed by ICP, processing time increases in proportion to the opening area of the through-hole. In addition, since a sandblasting apparatus that performs a sandblasting method is less expensive than an etching apparatus that performs an ICP process, capital investment can be reduced. Therefore, the manufacturing cost of the first through wiring 311 and the second through wiring 312 can be reduced.

  Further, by forming the first recesses 351 and 361 and the second recesses 352 and 362 constituting the first through hole 35 and the second through hole 36 by sandblasting, the first through hole 35 and the second through hole 36 are formed. The first through-holes 35 and the second through-holes 36 can be formed in the drive circuit board 30 that is relatively thicker than when formed by laser processing. That is, the formation of the through hole by laser processing has a limitation on the thickness of the drive circuit board 30 to be processed, and when the through hole is formed by laser processing on the relatively thick drive circuit board 30, the opening area is small Only wide through holes can be formed at low density. In the present embodiment, the first recesses 351 and 361 and the second recesses 352 and 362 that form the first through-hole 35 and the second through-hole 36 are formed by a sandblast method, so that a relatively thick drive compared to laser processing. The first through-hole 35 and the second through-hole 36 having relatively small openings can be formed in the circuit board 30 at a high density. In addition, since the sandblasting apparatus that performs the sandblasting method is less expensive than the laser processing apparatus that performs the laser processing, the capital investment can be reduced. Therefore, the manufacturing cost of the first through wiring 311 and the second through wiring 312 can be reduced.

  In addition, by forming the first concave portions 351 and 361 and the second concave portions 352 and 362 by a sandblast method, it is possible to prevent generation of burrs on the surface of the drive circuit board 30 which is generated when formed by laser processing, ICP, drill, or the like. Contamination due to the attachment of debris can be suppressed. By the way, when burrs are formed on the surface of the drive circuit board 30, when the drive circuit board 30 is joined with another member, the drive circuit board 30 and the other members are pressed and brought into contact with each other. The stress concentrates on the burrs, and there is a possibility that breakage such as cracks may occur from the burrs. In the present embodiment, it is possible to suppress the occurrence of burrs on the surface of the drive circuit board 30 and to suppress breakage such as cracks. In general, during laser processing, adhesion of debris and the like is suppressed by forming a protective film on the surface of the substrate, but debris adheres to the protective film, and debris also adheres to the interface between the substrate and the protective film. Due to the adhesion, debris is present on the substrate surface when the protective film is peeled off.

  Furthermore, by providing the first recessed portion 351 and the second recessed portion 352 in the first through-hole 35, the first through-hole 35 is formed in the first direction in the third direction Z which is the through direction, as compared with the case where the first through-hole 35 is formed straight. The area of the inner wall surface to which the through wiring 311 adheres can be increased. Therefore, the adhesion between the first through-wiring 311 and the inner wall of the first through-hole 35 can be improved, and the displacement of the first through-wiring 311 with respect to the first through-hole 35 can be suppressed.

  In addition, by forming the first concave portions 351 and 361 and the second concave portions 352 and 362 by a sandblast method, irregularities are formed on the surface of the inner wall surface to increase the surface roughness. it can. Therefore, the adhesion between the inner wall surfaces of the first through hole 35 and the second through hole 36 and the first through wiring 311 and the second through wiring 312 can be further improved by the anchor effect.

  Further, the first through-hole 35 and the second through-hole 36 have so-called constrictions in which openings are narrowed at portions where the first recesses 351 and 361 communicate with the second recesses 352 and 362. For this reason, when a temperature change occurs, the first through wiring 311 and the second through wiring 312 become the first through wiring 311 due to a difference in linear expansion coefficient between the drive circuit board 30 and the first through wiring 311 and the second through wiring 312. It is possible to suppress displacement from occurring in the third direction Z with respect to the through hole 35 and the second through hole 36, and to protrude from one of the first main surface 301 and the second main surface 302. This suppresses the displacement of the first through wiring 311 and the second through wiring 312 with respect to the first through hole 35 and the second through hole 36, and disconnects the wiring on the first main surface 301 and the second main surface 302. Can be suppressed. That is, in the present embodiment, the contact area between the first through-hole 35 and the second through-hole 36 and the first through-wire 311 and the second through-wire 312 is increased, and the adhesion is improved. By forming at least a part of the second through hole 36 by sandblasting and roughening the surface to improve the adhesion, and forming a so-called constriction having a narrow opening at the center, the first through wiring 311 and It is possible to synergistically suppress displacement of the second through wiring 312 in the through direction with respect to the first through hole 35 and the second through hole 36.

  In the manufacturing method of the recording head 1 according to the present embodiment described above, the drive circuit 120 is arranged in a face-up arrangement, so that an input section to which an external wiring from an external control circuit or the like is connected is provided in the drive circuit 120. No space is needed. Therefore, an area for forming such an input section is not required for the drive circuit board 30, and the drive circuit board 30 can be downsized. Further, since the first through wiring 311 and the second through wiring 312 extend in the third direction Z penetrating the drive circuit board 30, the through wiring is shortened, and the drive circuit board 30 is enlarged on a horizontal plane. That can be avoided. In particular, in the present embodiment, the first recesses 351 and 361 and the second recesses 352 and 362 forming the first through hole 35 and the second through hole 36 in which the first through wiring 311 and the second through wiring 312 are formed are formed. The first through-holes 35 and the second through-holes 36 can be formed with a fine opening at a high density by being formed by the sandblast method. Therefore, the space for forming the first through wiring 311 and the second through wiring 312 is omitted, and the drive circuit board 30 can be downsized.

  As described above, according to the method for manufacturing the recording head 1 according to the present embodiment, the drive circuit board 30 can be downsized, and the recording head 1 can be downsized. Since the recording head 1 can be reduced in size, it is possible to cope with the high density of the nozzle openings 21 and to manufacture the recording head 1 capable of discharging ink at a high density.

  In the present embodiment, the drive circuit board 30 on which the first bumps 31 and the second bumps 32 and the first through wirings 311 and the second through wirings 312 are formed in advance is simply joined to the flow path forming substrate 10. The first through wiring 311 and the second through wiring 312 can be electrically connected to the individual wiring 91 and the common wiring 92. Thereby, after the flow path forming substrate 10 and the drive circuit substrate 30 are joined, the manufacturing process is reduced as compared with the case where the connection wiring is connected to the lead electrode drawn out of the holding section 320 by film formation and lithography. It can be simplified.

  In the present embodiment, the first recess 351 and the second recess 352 are formed by the sand blast method to form the first through-hole 35 and the second through-hole 36. However, the present invention is not particularly limited thereto. For example, as shown in FIG. 28, the first through hole 35 may have a configuration including a first recess 351, a second recess 352, and a communication hole 353 communicating the first recess 351 and the second recess 352. Good. Here, a method of manufacturing the first through-hole 35 having such a communication hole 353 will be described with reference to FIGS. 29 to 32 are main-portion cross-sectional views illustrating a method of manufacturing a recording head.

  As shown in FIG. 29, the first concave portion 351 and the second concave portion 352 are formed in the driving circuit board wafer 130 by the sandblast method by the same method as that of FIG. 11 described above. At this time, the first recess 351 and the second recess 352 are communicated.

  Next, as shown in FIG. 30, the innermost part of the inner wall of the first through hole 35 where the first recess 351 and the second recess 352 communicate with each other is removed by, for example, laser processing (communication hole forming step). ). Thereby, the first through hole 35 having the first concave portion 351 and the second concave portion 352 formed by the sand blast method and the communication hole 353 formed by the laser processing can be formed. Of course, the second through hole 36 can be formed by the same process.

  By configuring the first through hole 35 by the first recess 351, the second recess 352, and the communication hole 353 in this manner, even if the opening areas of the first recess 351 and the second recess 352 are further reduced, the first recess 35 is formed. 351 and the second concave portion 352 can be reliably communicated. Further, by providing the communication hole 353, the first through hole 35 can be formed in the drive circuit board 30 having a relatively large thickness. That is, when the drive circuit board 30 has a large thickness, the first recess 351 and the second recess 352 having a small opening cannot communicate with each other. However, by providing the communication hole 353, the drive circuit board having a relatively large thickness is provided. The first concave portion 351 and the second concave portion 352 having a small opening can communicate with each other. Further, by providing the communication hole 353, the opening of the narrowest portion of the first through hole 35 can be expanded as compared with the case where the first recess 351 and the second recess 352 are directly connected. Therefore, it is possible to increase the cross section of the first through wiring 311 formed in the first through hole 35 and reduce the wiring resistance. In particular, by providing the communication hole 353 with the same inner diameter in the third direction Z, it is possible to suppress an increase in wiring resistance due to a decrease in the cross-sectional area of the first through wiring 311. Of course, the same applies to the second through hole 36 and the second through wiring 312.

  Furthermore, since the first concave portion 351 and the second concave portion 352 are formed by a sand blast method, and the communication hole 353 is formed by laser processing a position away from the surface of the drive circuit board 30, burrs and debris generated by the laser processing are formed. Can be suppressed from forming or adhering to the surface of the drive circuit board 30, that is, the first main surface 301 and the second main surface 302. Therefore, even in the case of the first through hole 35 having the communication hole 353, generation of burrs and debris is suppressed, and destruction of the drive circuit board 30 and other members joined thereto due to burrs and debris is suppressed. Can be.

  The communication hole 353 of the first through hole 35 can be formed by laser processing even when the first recess 351 and the second recess 352 are not connected to each other when they are formed by sandblasting. it can.

  That is, as shown in FIG. 31, the first concave portion 351 and the second concave portion 352 are formed on both sides of the driving circuit substrate wafer 130 by a sandblast method. At this time, the first concave portion 351 and the second concave portion 352 are formed so as not to communicate with each other. Next, as shown in FIG. 32, the bottom surface of the first concave portion 351 or the second concave portion 352 is irradiated with a laser beam and laser-processed, thereby forming a communication hole 353 for communicating the first concave portion 351 with the second concave portion 352. Is formed (communication hole forming step). The formation of burrs and debris on the surface of the drive circuit board 30 can also be suppressed by such a method of forming the communication holes 353. In addition, according to the method of forming the first through-hole 35 shown in FIGS. 31 and 32, the first through-hole 35 is formed with a relatively small opening in the drive circuit board wafer 130 having a larger thickness. Becomes possible.

(Embodiment 2)
FIG. 33 is a cross-sectional view of a main part of a recording head according to Embodiment 2 of the present invention. Note that the same members as those in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

  As shown in FIG. 33, in the present embodiment, the first through hole 35 communicates with the first recess 351, the third recess 354 communicating with the first recess 351, the second recess 352, and the second recess 352. And a fourth concave portion 355 to be formed.

  Here, the third concave portion 354 and the fourth concave portion 355 are provided between the first concave portion 351 and the second concave portion 352, and in the present embodiment, the bottom surfaces of the third concave portion 354 and the fourth concave portion 355 are provided. Are in direct communication with each other.

  Similarly to the first concave portion 351, the third concave portion 354 has a larger inclination from the first main surface 301 to the second main surface 302 with respect to the third direction Z, which is the penetrating direction of the first through hole 35. As such, it is formed with a concave curved surface.

  The inclination of the inner wall of the first recess 351 on the third recess 354 side is larger than the inclination of the third recess 354 on the first recess 351 side. That is, the opening of the third recess 354 is smaller than the opening of the first recess 351.

  Like the second recess 352, the fourth recess 355 has a larger inclination from the second main surface 302 toward the first main surface 301 with respect to the third direction Z, which is the direction in which the first through-hole 35 penetrates. As such, it is formed with a concave curved surface.

  The inclination of the inner wall of the second recess 352 on the fourth recess 355 side is larger than the inclination of the fourth recess 355 on the second recess 352 side. That is, the opening of the fourth recess 355 is smaller than the opening of the second recess 352.

  The first through wiring 311 is formed in the first through hole 35 including the first recess 351, the second recess 352, the third recess 354, and the fourth recess 355.

  Here, a method of manufacturing the first through hole 35 of the present embodiment will be described with reference to FIGS. 34 and 35 are main-portion cross-sectional views illustrating the method of manufacturing the recording head according to the second embodiment.

  As shown in FIG. 34, the first concave portion 351 and the second concave portion 352 are formed on the driving circuit board wafer 130 by the sandblast method by the same method as that of FIG. 11 described above. At this time, the first recess 351 and the second recess 352 do not communicate with each other. Then, by continuously performing the sandblasting method, the third concave portion 354 and the fourth concave portion 355 are formed as shown in FIG. 35 (third concave portion forming step and fourth concave portion forming step). That is, in the sandblasting method, when the particles reach a predetermined depth, the particles are concentrated at the center, and the openings are formed in a stepped manner. As a result, a third recess 354 and a fourth recess 355 are formed. That is, the third concave portion 354 and the fourth concave portion 355 are formed when the first through hole 35 having a small opening is formed in the drive circuit board 30 having a relatively large thickness by the sandblast method.

  The first and third recess forming steps and the second and fourth recess forming steps are performed in different steps, but the order is not particularly limited.

  Further, the third concave portion 354 and the fourth concave portion 355 can also be formed by gradually expanding the opening portion of the resist layer 411 which is a mask used when forming the first concave portion 351 and the second concave portion 352. it can. That is, for example, after forming an opening for forming the third concave portion 354 and the fourth concave portion 355 in the resist layer 411 and performing a sand blast method, after forming a concave portion having a predetermined depth, the opening of the resist layer 411 is formed. Is expanded to the size of the first concave portion 351 and the second concave portion 352, and the sand blast method is performed. Thereby, the opening can be formed deeply with the shape before the opening is widened, and a concave portion having a step can be formed.

  As described above, by forming the first through hole 35 by the first recess 351, the second recess 352, the third recess 354, and the fourth recess 355, the first through hole 35 can be formed without increasing the opening of the first through hole 35. The contact area with the through wiring 311 can be increased to further improve the adhesion.

  Similarly, the second through hole 36 may have a third recess and a fourth recess in addition to the first recess 361 and the second recess 362.

  Further, in the present embodiment, the third recess 354 and the fourth recess 355 of the first through hole 35 are directly communicated with each other. However, the present invention is not particularly limited to this. For example, as shown in FIG. The recess 354 and the fourth recess 355 may be communicated with each other by the communication hole 353. The communication hole 353 may be formed by laser processing after the communication between the third concave portion 354 and the fourth concave portion 355, similarly to the first embodiment described above, and the third concave portion 354 and the fourth concave portion 355 may be formed. The communication hole 353 may be formed by laser processing from a state in which the communication holes are not connected.

  As described above, the first through hole 35 is constituted by the first concave portion 351, the second concave portion 352, the communication hole 353, the third concave portion 354, and the fourth concave portion 355, so that the first through hole 35 having a small opening is further thickened. It is possible to form a high density on the thick drive circuit board 30.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic structure of this invention is not limited to what was mentioned above.

  In the first and second embodiments described above, the first bump 31 and the second bump 32 are provided on the drive circuit board 30; however, the present invention is not necessarily limited to such an aspect. The first bump 31 and the second bump 32 may be provided on the flow path forming substrate 10 side.

  In the first and second embodiments, the second bumps 32 are provided between the two rows of the piezoelectric actuators 310. However, the present invention is not limited to such an embodiment. At any position. For example, the second bump 32 may be provided in a region on an extension of the piezoelectric actuator row 310. That is, in the first direction X, the second bump 32 may be provided in a region outside the piezoelectric actuator row 310, and the common wiring 92 may be provided up to a position facing the second bump 32.

  Furthermore, in Embodiments 1 and 2, one drive circuit 120 is provided for two rows of piezoelectric actuators 300, but the present invention is not particularly limited to this. For example, the drive circuit 120 may be provided for each row of the piezoelectric actuators 300 in one row.

  Further, the adhesive layers 39 are provided on both sides in the second direction Y for each of the three rows of the first bumps 31 and the second bumps 32. However, the present invention is not particularly limited to this. It is sufficient that they are provided at least on both sides of the first bump 31.

  Furthermore, in Embodiments 1 and 2 described above, one drive circuit board 30 is provided for one flow path forming substrate 10, but the present invention is not particularly limited to this. For example, the drive circuit board 30 may be provided for each piezoelectric actuator row 310. That is, two drive circuit boards 30 may be provided for one flow path forming board 10.

  In the first and second embodiments, the common wiring 92 is extended from the second electrode 80 that is the common electrode of the two rows of the piezoelectric actuators 310. That is, the common wiring 92 is a wiring common to the two piezoelectric actuator rows 310, but is not limited to such an embodiment. For example, the common wires 92 may be provided from the second electrodes 80 of the piezoelectric actuator row 310, respectively. That is, the common wires 92 may be individually drawn out from the one piezoelectric actuator row 310 and the other piezoelectric actuator row 310, and the common wires 92 may be in contact with the second bumps 32. It is preferable that the common wiring 92 is common to the two piezoelectric actuator rows 310. By using the common wiring 92 common to the two rows of piezoelectric actuators 310, the number of the second through-wirings 312 and the second through-holes 36 connected via the second bumps 32 is smaller than the individual common wirings 92. The number can be reduced and the size can be reduced.

  Further, in the first and second embodiments, the second bump 32 is formed on the core portion 33 extending along the first direction X so as to cover the core portion 33 with a metal elongated in the first direction X. Although the configuration is such that the film 34 is formed, it is not limited to such an embodiment. For example, the second bump 32 may be provided for each common wiring 92. That is, the second bump 32 may be provided for each of the plurality of common wirings 92 in the same manner as the first bump 31 is provided for each of the plurality of individual wirings 91. In this case, a second through hole 36 is formed for each second bump 32, and a second through wiring 312 is provided to connect to the drive circuit 120.

  In the first and second embodiments, two second through holes 36 are provided on both sides of the second bump 32 in the first direction X. However, the present invention is not limited to such an aspect, and the position and the number are arbitrary. .

  Furthermore, in the first and second embodiments described above, the thin-film piezoelectric actuator 300 was described as a driving element that causes a pressure change in the pressure generating chamber 12, but the present invention is not particularly limited thereto. A thick-film type piezoelectric actuator formed by a method such as pasting or a longitudinal vibration type piezoelectric actuator in which a piezoelectric material and an electrode forming material are alternately laminated and stretched in the axial direction can be used. In addition, as a driving element, a heating element is arranged in a pressure generating chamber, and a liquid droplet is discharged from a nozzle opening by a bubble generated by heat generation of the heating element, or static electricity is generated between a diaphragm and an electrode. For example, a so-called electrostatic actuator that deforms a diaphragm by electrostatic force to discharge droplets from nozzle openings can be used.

  Note that the recording head 1 of the embodiment is mounted on an ink jet recording apparatus which is an example of a liquid ejecting apparatus. FIG. 37 is a schematic view showing an example of the ink jet recording apparatus.

  As shown in the figure, in an ink jet type recording apparatus I, a recording head 1 is provided with a cartridge 2 constituting an ink supply means detachably provided, and a carriage 3 on which the recording head 1 is mounted is a carriage attached to an apparatus main body 4. The shaft 5 is provided movably in the axial direction.

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

  In the above-described ink jet recording apparatus I, an example in which the recording head 1 is mounted on the carriage 3 and moves in the main scanning direction has been exemplified. However, the present invention is not particularly limited thereto. For example, the recording head 1 is fixed, The present invention can be applied to a so-called line type recording apparatus that performs printing only by moving a recording sheet S such as paper in the sub-scanning direction.

  Further, in the above-described example, the ink jet recording apparatus I has a configuration in which the cartridge 2 as the liquid storage means is mounted on the carriage 3, but is not particularly limited thereto. The storage means and the recording head 1 may be connected to the apparatus main body 4 via a supply pipe such as a tube. Further, the liquid storage means may not be mounted on the ink jet recording apparatus.

  Furthermore, the present invention is intended for a wide variety of heads, for example, used in the manufacture of various types of recording heads such as ink jet recording heads used in image recording apparatuses such as printers, and color filters such as liquid crystal displays. The present invention can also be applied to an electrode material ejecting head used for forming electrodes such as a color material ejecting head, an organic EL display, and an FED (field emission display), and a biological organic matter ejecting head used for producing a biochip.

  Further, the present invention is broadly applied to MEMS devices, and can be applied to MEMS devices other than the recording head. Examples of the MEMS device include a device that detects an external signal and changes a current value before and after the detection. Examples of such a MEMS device include an ultrasonic device, a motor, a pressure sensor, a pyroelectric element, and a ferroelectric element. Further, a completed body using these MEMS devices, for example, a liquid ejecting apparatus using the head, an ultrasonic sensor using the ultrasonic device, a robot using the motor as a driving source, and the pyroelectric element MEMS devices include an IR sensor using a ferroelectric memory and a ferroelectric memory using a ferroelectric element. Then, by using the through wiring with reduced wiring resistance of the present invention in the MEMS device, it becomes possible to detect a minute current.

  Further, the present invention is broadly applied to through wirings, and can be applied to through wirings other than MEMS devices.

  I: inkjet recording apparatus (liquid ejecting apparatus), 1: inkjet recording head (liquid ejecting head), 10: flow path forming substrate, 12: pressure generating chamber, 20: nozzle plate, 30: drive circuit board, 31: 1st bump, 32 ... 2nd bump, 35 ... 1st through hole, 36 ... 2nd through hole, 91 ... individual wiring, 92 ... common wiring, 100 ... manifold, 120 ... drive circuit, 300 ... piezoelectric actuator, 310 ... Piezoelectric actuator row, 311 first through wiring, 312 second through wiring, 351, 361 first recess, 352, 362 second recess, 353 communication hole, 354 third recess, 355 fourth recess

Claims (10)

A through hole, a through wiring formed in the through hole,
The through hole,
A first recess formed at one end of the through hole;
A second recess formed at the other end of the through hole opposite to the one end;
Has,
The inclination of the inner wall of the first concave portion increases from the one end toward the other end with respect to the penetration direction of the through hole,
An inner wall of the second recess, Ri is Na larger inclination as the through direction of the through hole toward the one end from the other end,
The through hole,
A third recess communicating with the first recess,
And a fourth recess communicating with the second recess.
The third recess and the fourth recess are provided between the first recess and the second recess,
The inclination of the inner wall of the first recess on the third recess side is larger than the inclination of the third recess on the first recess side,
A through wiring, wherein the inclination of the second concave portion on the side of the fourth concave portion is larger than the inclination of the fourth concave portion on the side of the second concave portion.   2. The through wiring according to claim 1, wherein the third recess and the fourth recess are connected by a communication hole. 3. 3. The through wiring according to claim 2 , wherein an opening diameter of each of the first recess and the second recess is larger than a maximum diameter of the communication hole. 4. A liquid jet head comprising the through wiring according to any one of claims 1 to 3 . A method of manufacturing a through wiring formed in a through hole,
A first concave portion forming step of forming a first concave portion in which an inner wall at one end of the through hole has a larger inclination toward the other end with respect to a penetrating direction of the through hole;
A second recess forming step in which the inner wall of the other end of the through hole forms a second recess whose inclination increases toward the one end;
A wiring forming step of forming a through wiring in the through hole,
The first concave portion forming step and the second concave portion forming step use a sand blast method ,
The first recess forming step includes a third recess forming step of forming a third recess communicating with the first recess,
The method for manufacturing a through wiring, wherein the second recess forming step includes a fourth recess forming step of forming a fourth recess communicating with the second recess. 6. The method according to claim 5 , further comprising a communication hole forming step of forming a communication hole connecting the first concave portion and the second concave portion. 6. The method for manufacturing a through wiring according to claim 5 , further comprising a communication hole forming step of forming a communication hole connecting the third recess and the fourth recess. The method of manufacturing a through wiring according to any one of claims 5 to 7 , wherein the wiring forming step includes a plating method. A method for manufacturing a MEMS device, comprising the method for manufacturing a through wiring according to any one of claims 5 to 8 . A method for manufacturing a liquid jet head, comprising the method for manufacturing a MEMS device according to claim 9 .

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