JP2017113918A - Through wiring, mems device, liquid injection head, manufacturing method for through wiring, manufacturing method for mems device and manufacturing method for liquid injection head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide through wiring suppressing contamination due to a burr and debris, suppressing a positional deviation of the through wiring from a through hole and improving a degree-of-freedom of formation of the through hole and the through wiring, and an MEMS device, a liquid injection head, a manufacturing method for the through wiring, a manufacturing method for the MEMS device and a manufacturing method for the liquid injection head.SOLUTION: Through wiring 311 is formed in a through hole 35. The through hole 35 includes: a first recessed portion 351 formed at one end of the through hole 35; and a second recessed portion 352 formed at the other end of an opposite side to the one end of the through hole 35. In the through hole 35, an inner wall of the first recessed portion 351 has an inclination increasing as it approaches toward the other end from the one end in a penetration direction of the through hole 35, and an inner wall of the second recessed portion 352 has an inclination increasing as it approaches toward the one end from the other end in the penetration direction of the through hole 35.SELECTED DRAWING: Figure 4

Description

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

  Some MEMS (Micro Electro Mechanical Systems) devices typified 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, there has been proposed one in which a through hole is formed in a substrate by etching, drilling or sand blasting, and a through wiring is formed in the through hole (for example, see Patent Document 1).

JP, 2015-171803, A

  However, when the through hole is 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 with respect to the through hole of the through wiring occurs due to temperature change, and the wiring formed on the surface of the substrate due to the positional shift of the through wiring There is a problem of disconnection.

  And the through-hole in which the through-wiring used for a MEMS device etc. is provided may require size reduction and high density of an opening, and the freedom degree of a through-hole and through-wiring is desired.

  In view of such circumstances, the present invention suppresses contamination due to burrs and debris, suppresses displacement of the through wiring with respect to the through hole, and improves the freedom of formation of the through hole and the through wiring, and the MEMS device An object of the present invention is to provide a liquid ejecting head, a method of manufacturing a through wiring, a method of manufacturing a MEMS device, and a method of manufacturing a liquid ejecting head.

  An aspect of the present invention that solves the above problem is a through hole and a through wiring formed in the through hole, the through hole including a first recess formed at one end of the through hole, and the through hole. A second recess formed at the other end opposite to the one end, and 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 inner wall of the second recess is in the through wiring characterized in that the inclination increases from the other end to the one end with respect to the through direction of the through hole.

  In this aspect, 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. Moreover, the position shift with respect to the through-hole of penetration wiring can be suppressed by setting it as the constriction shape in the connection part of a 1st recessed part and a 2nd recessed part. Furthermore, by providing the through wiring inside the first recess and the second recess, the cross-sectional area can be increased and the wiring resistance can be reduced.

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

  The first recess and the second recess are preferably communicated with each other through a communication hole. According to this, the length in the penetration direction of the through hole can be extended without increasing the opening of the through hole by providing the communication hole.

  Moreover, it is preferable that the said 3rd recessed part and the said 4th recessed part are connected by the communicating hole. According to this, the length in the penetration direction of the through hole can be extended without increasing the opening of the through hole by providing the communication hole.

  Moreover, it is preferable that each opening diameter of the said 1st recessed part and the said 2nd recessed part is larger than the largest diameter of the said communicating hole. According to this, it is possible to reduce the wiring resistance by reducing the electrical resistance value of the through wiring provided inside the first recess and the second recess. Moreover, the position shift with respect to the through-hole of a through-wire can be suppressed by setting it as the shape narrowed in the communicating hole which connects a 1st recessed part and a 2nd recessed part.

  Furthermore, another aspect of the present invention is a MEMS device that detects a signal from the outside and changes a current value before and after the detection, wherein a part of the wiring through which the current passes is the through wiring of the above aspect. In the featured MEMS device.

  In this aspect, a minute current can be detected.

  According to another aspect of the invention, there is provided a liquid ejecting head including the through wiring according to the above aspect.

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

  Furthermore, another aspect of the present invention is a method for manufacturing a through-wiring formed in a through-hole, wherein an inner wall of one end of the through-hole is inclined toward the other end with respect to the through-direction of the through-hole. A first recess forming step for forming a first recess that increases, a second recess forming step for forming a second recess in which the inner wall of the other end of the through-hole increases in inclination toward the one end, and the penetration A through-wiring forming process for forming a through-wiring in the hole, wherein the first recess forming process and the second recess forming process use a sandblasting method.

  In such an aspect, the first concave portion and the second concave portion are formed by the sandblasting method, whereby the inner wall of the first concave portion is inclined more gradually from one end to the other end with respect to the penetrating direction of the through hole. The inner wall of the recess can be formed so that the inclination increases as it goes from the other end to the one end with respect to the penetration 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 ICP. Furthermore, by forming the first concave portion and the second concave portion by the sand blast method, through holes having a small opening can be easily and densely formed on a relatively thick substrate as compared with laser processing. Furthermore, a sand blasting apparatus that performs the sand blasting method is less expensive than an apparatus that performs laser processing or an etching apparatus that performs ICP processing, and thus can reduce capital investment.

  Here, the first recessed portion forming step includes a third recessed portion forming step for forming a third recessed portion communicating with the first recessed portion, and the second recessed portion forming step includes a fourth recessed portion communicating with the second recessed portion. It is preferable to include the 4th recessed part formation process which forms. According to this, the inclination of the inner wall of the first concave portion on the third concave portion side is larger than the inclination of the third concave portion on the first concave portion side by the sandblasting method, and the inclination of the second concave portion on the fourth concave portion side is the fourth. It can be easily formed in a shape larger than the inclination of the concave portion on the second concave portion side.

  Moreover, it is preferable to further include a communication hole forming step of forming a communication hole that connects the first recess and the second recess. According to this, a communicating hole can be formed.

  Moreover, it is preferable to further include a communication hole forming step of forming a communication hole connecting the third recess and the fourth recess. According to this, a communicating hole can be formed.

  Moreover, it is preferable that the said wiring formation process includes the plating method. According to this, the through wiring can be formed by a plating method.

  Furthermore, another aspect of the present invention resides in a method for manufacturing a MEMS device including the method for manufacturing a through wiring according to the above aspect.

  In this aspect, through holes and through wirings with small openings can be formed with high density, and downsizing can be achieved.

  According to another aspect of the invention, there is provided a method of manufacturing a liquid ejecting head including the method of manufacturing a MEMS device according to the above aspect.

  In this aspect, through holes and through wirings with small openings can be formed with high density, and downsizing can be achieved.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a plan view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view taken along line AA ′ in FIG. 2 according to the first embodiment. It is sectional drawing to which the principal part of FIG. 3 which concerns on Embodiment 1 was expanded. 3 is a plan view of a main part of the flow path forming substrate according to Embodiment 1. FIG. FIG. 3 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 cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 6 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 cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 4 is a cross-sectional view illustrating the recording head manufacturing method according to the first embodiment. FIG. 6 is a cross-sectional view of a main part of a recording head according to a second embodiment. 5 is a cross-sectional view illustrating a method for manufacturing a recording head according to Embodiment 2. FIG. 5 is a cross-sectional view illustrating a method for manufacturing a recording head according to Embodiment 2. FIG. FIG. 10 is a cross-sectional view of a main part showing a modification of the recording head according to the second embodiment. 1 is a schematic diagram illustrating an ink jet recording apparatus according to an 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 the first embodiment. In this embodiment, an ink jet recording head that discharges ink (hereinafter also simply referred to as a recording head) 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 (plan view on the liquid ejection surface 20a side), and FIG. 3 is a cross-sectional view taken along line AA ′ of FIG. FIG. 4 is an enlarged cross-sectional view of the main part of FIG. 3, and FIG. 5 is a plan view of the main part of the flow path forming substrate 10.

  As shown in the figure, 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 drive circuit substrate 30 that is a wiring substrate of the present embodiment, and a compliance substrate 45. Prepare.

For the flow path forming substrate 10, 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, LaAlO ₃ , or the like can be used. In the present embodiment, the flow path forming substrate 10 is made of a silicon single crystal substrate. This flow path forming substrate 10 is anisotropically etched from one side so that the pressure generating chambers 12 partitioned by the plurality of partition walls are arranged in parallel with a plurality of nozzle openings 21 through which ink is ejected. 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. Further, the flow path forming substrate 10 is provided with a plurality of rows in which the pressure generation chambers 12 are arranged in parallel in the first direction X, and in this embodiment, two rows. An arrangement direction in which a plurality of rows of the pressure generation chambers 12 in which the pressure generation chambers 12 are formed along the first direction X is provided is hereinafter referred to as a second direction Y. Furthermore, 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. 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 being orthogonal.

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

  On one side of the flow path forming substrate 10 (on 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 stacked. 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 opposite surface side of the communication plate 15 from the flow path forming substrate 10 are provided. .

  The communication plate 15 is provided with a nozzle communication path 16 that communicates the pressure generation chamber 12 and the nozzle opening 21. The communication plate 15 has a larger area than the flow path forming substrate 10, and the nozzle plate 20 has a smaller area 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 generating chamber 12 can be separated from each other, so that the ink in the pressure generating chamber 12 is contained in the ink generated by the ink near the nozzle opening 21. Less susceptible to thickening due to moisture evaporation. Further, since the nozzle plate 20 only needs to cover the opening of the nozzle communication path 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, a surface on which the nozzle openings 21 of the nozzle plate 20 are opened and ink droplets are ejected is referred to as a liquid ejecting surface 20a.

  The communication plate 15 is provided with a first manifold portion 17 and a second manifold portion 18 that constitute a part of the manifold 100.

  The first manifold portion 17 is provided through the communication plate 15 in the thickness direction (the stacking direction of the communication plate 15 and the flow path forming substrate 10). The second manifold portion 18 is provided to open to the nozzle plate 20 side of the communication plate 15 without penetrating the communication plate 15 in the thickness direction.

  Further, the communication plate 15 is provided with a supply communication passage 19 that communicates with one end portion in the second direction Y of the pressure generation chamber 12 for each pressure generation chamber 12. The supply communication path 19 communicates the second manifold portion 18 and the pressure generation chamber 12.

  As the 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 the flow path forming substrate 10. That is, when a material having a linear expansion coefficient that is significantly different from that of the flow path forming substrate 10 is used as the communication plate 15, warping due to a difference in linear expansion coefficient between the flow path forming substrate 10 and the communication plate 15 due to heating or cooling. Will occur. In this embodiment, by using the same material as the flow path forming substrate 10 as the communication plate 15, that is, a silicon single crystal substrate, it is possible to suppress the occurrence of warping due to heat, cracking due to heat, peeling, and the like.

  In the nozzle plate 20, nozzle openings 21 communicating with the pressure generation chambers 12 through the nozzle communication passages 16 are formed. Such nozzle openings 21 are arranged in parallel in the first direction X, and two rows of nozzle openings 21 arranged in parallel 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, peeling, and the like are suppressed. can do.

  On the other hand, a diaphragm 50 is formed on the opposite side of the flow path forming substrate 10 from the communication plate 15 (on the side of the drive circuit board 30 and in the + Z direction). In the present embodiment, 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 as the diaphragm 50. I made it. The liquid flow path such as the pressure generation chamber 12 is formed by anisotropically etching the flow path forming substrate 10 from one surface side (the surface side to which the communication plate 15 is bonded). The other surface of the liquid flow path is defined by the elastic film 51. Of course, the diaphragm 50 is not particularly limited to this, and either the elastic film 51 or the insulator film 52 may be provided, or 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 pressure generation chambers 12 are arranged in parallel along the first direction X on the flow path forming substrate 10, and two rows of pressure generation chambers 12 are arranged in parallel along the second direction Y. Has been. The piezoelectric actuators 300 are arranged in parallel in the first direction X to form a piezoelectric actuator row 310, and the two piezoelectric actuator rows 310 are arranged in parallel 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 separated for each pressure generating chamber 12 and constitutes an independent electrode for each active part which is a substantial driving part of the piezoelectric actuator 300. The first electrode 60 is formed with a width narrower than the width of the pressure generation chamber 12 in the first direction X of the pressure generation chamber 12. That is, in the first direction X of the pressure generation chamber 12, the end portion of the first electrode 60 is located inside the region facing the pressure generation chamber 12. Further, in the second direction Y of the pressure generation chamber 12, both end portions of the first electrode 60 are extended to the outside of the pressure generation chamber 12, respectively. 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 continuously provided over the first direction X so that the second direction Y has a predetermined width. The width of the piezoelectric layer 70 in the second direction Y is wider than the width of the pressure generation chamber 12 in the second direction Y. Therefore, in the second direction Y of the pressure generation chamber 12, the piezoelectric layer 70 is provided to the outside of the pressure generation chamber 12.

  The end of the piezoelectric layer 70 on one end side in the second direction Y of the pressure generating chamber 12 (on the side opposite to the manifold 100) is located outside the end of the first electrode 60. That is, the end portion of the first electrode 60 is covered with the piezoelectric layer 70. In addition, the end of the piezoelectric layer 70 on the other end side that is the manifold 100 side in the second direction Y of the pressure generation chamber 12 is located on the inner side (the pressure generation chamber 12 side) than the end of the first electrode 60. The end portion 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 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, recesses 71 corresponding to the respective partitions between the pressure generation chambers 12 are formed. The width of the recess 71 in the first direction X is substantially the same as or wider than the width of each partition wall in the first direction. As a result, the rigidity of the portion (the so-called arm portion of the diaphragm 50) that opposes the end of the pressure generation chamber 12 of the diaphragm 50 in the second direction Y is suppressed, so that the piezoelectric actuator 300 can be displaced favorably. it can.

  The second electrode 80 is provided on the opposite side of the piezoelectric layer 70 from the first electrode 60 and constitutes a common electrode common to a plurality of active portions. Further, 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.

  Such a piezoelectric actuator 300 composed of 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, by applying a voltage between both electrodes, a piezoelectric strain is generated in the piezoelectric layer 70 sandwiched between the first electrode 60 and the second electrode 80. A portion where piezoelectric distortion occurs in the piezoelectric layer 70 when a voltage is applied to both electrodes is referred to as an active portion. On the other hand, a portion where no piezoelectric distortion occurs in the piezoelectric layer 70 is referred to as an inactive portion.

  As described above, the piezoelectric actuator 300 is common in that the first electrode 60 is provided individually 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 obtained. 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 it over a plurality of active portions, and the second electrode is provided separately for each active portion as an individual electrode. Also good. Further, as the diaphragm 50, the elastic film 51 and the insulator film 52 may not be provided, and only the first electrode 60 may function as the diaphragm. Further, the piezoelectric actuator 300 itself may substantially serve as a diaphragm.

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

  Further, a common wire 92 that is a lead-out wire is led out from the second electrode 80 of the piezoelectric actuator 300. In the present embodiment, the common wiring 92 is electrically connected to the second electrodes 80 of the two rows of piezoelectric actuators 300. The common wiring 92 is provided at a ratio of one for the plurality of active portions.

  A drive circuit board 30 having substantially the same size as the flow path forming substrate 10 is bonded to the surface of the flow path forming substrate 10 on the piezoelectric actuator 300 side. 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 flow path forming board side, and FIG. 7 is a cross-sectional view taken along the line BB ′ of FIG.

  The drive circuit substrate 30 is a semiconductor substrate in which a drive circuit 120 that drives the piezoelectric actuator 300 is provided on the surface opposite to the flow path forming substrate 10. A surface of the drive circuit board 30 that faces the flow path forming substrate 10 is a first main surface 301, and a surface opposite to the flow path forming substrate 10 is a second main surface 302.

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

  Further, 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 limited to such a mode. Not. The drive circuit 120 may be an active circuit that generates such a drive signal, or may be a circuit that includes only wiring that transmits 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 substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material or the like. 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 the first through hole 35 and the 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. 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 the insulating film 37 is formed of an insulating material. For example, silicon dioxide, silicon nitride, or the like can be used.

  A first bump 31 and a second bump 32 are provided on the first main surface 301 of the 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 part 33 formed of an elastic resin material and a metal film 34 formed on the surface of the core part 33.

  The core portion 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, or an epoxy resin, or a thermosetting insulating resin.

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

  The core portion 33 is pressed so that the drive circuit substrate 30 and the flow path forming substrate 10 are relatively close to each other, so that the tip shape thereof is elastic so as to follow the surface shapes 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 is warped or swelled, the core portion 33 is deformed following this, whereby the first bump 31 and the second bump 32 and the individual wiring 91 and The common wiring 92 can be reliably connected.

  In the present embodiment, the core portion 33 is continuously arranged linearly in the first direction X. In addition, in the second direction Y, three core portions 33 are provided, that is, two outside the two rows of piezoelectric actuator rows 310 and one between the two rows of piezoelectric actuator rows 310. Yes. Each core portion 33 provided outside the two rows of 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 piezoelectric actuator rows 310. The core portion 33 provided on the second portion constitutes the second bump 32 connected to the common wiring 92 of the two rows of piezoelectric actuator rows 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 portion 33. The metal film 34 is formed of a metal or an alloy such as Au, TiW, Cu, Cr (chromium), Ni, Ti, W, NiV, Al, Pd (palladium), or lead-free solder, and a single layer thereof. Or what laminated | stacked multiple types may be sufficient. The metal film 34 is deformed following the surface shapes of the individual wiring 91 and the common wiring 92 due to elastic deformation of the core portion 33, and is metal-bonded to the individual wiring 91 and the common wiring 92.

  The metal film 34 connected to the individual wiring 91 is disposed in the first direction X at the same pitch as the individual wiring 91 on the surface of the core portion 33. In addition, the metal film 34 connected to the common wiring 92 extends along 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 be in contact with 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, 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 substrate 10 of the present embodiment are bonded by the adhesive layer 39, so that the first bump 31 and the second bump 32, the individual wiring 91 and the common wiring 92 are connected. Are fixed in contact with each other.

  Here, the adhesive layer 39 is formed of 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 formed with high accuracy.

  In the present embodiment, the adhesive layer 39 is provided on both sides of the first bump 31 and both sides of the second bump 32, that is, both sides in the second direction Y across the first bump 31 and the second bump 32. ing. Since the three first bumps 31 and the 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 is Six are provided in the second direction Y. In addition, the adhesive layer 39 arranged side by side in the second direction Y is 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 have a rectangular frame shape in plan view so as to surround each row of the piezoelectric actuator rows 310.

  Thus, the adhesive layer 39 that joins the flow path forming substrate 10 and the drive circuit board 30 is a space in which the piezoelectric actuator 300 is disposed between the flow path formation substrate 10 and the drive circuit board 30. A holding part 320 is formed. In the present embodiment, since the adhesive layer 39 is continuously provided around each of the piezoelectric actuator rows 310, the piezoelectric actuator row 310 is provided between the flow path forming substrate 10 and the drive circuit board 30. The holding part 320 is provided independently corresponding to each.

  The holder 320 may be a sealed space that is blocked from the outside, or may be a non-sealed space that is partially communicated with the outside.

  The drive circuit board 30 is provided with a first through hole 35 and a second through hole 36 which are 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 recess 351 provided on the first main surface 301 side which is one end of the first through hole 35 and a second main surface 302 side which is the other end of the first through hole 35. And a second recess 352 provided.

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

  In addition, the inner wall of the second recess 352 is directed from the other end to the one end, that is, from the second main surface 302 to the first main surface 301 with respect to the third direction Z that is the penetrating 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 so that the inner wall has a so-called concave curved surface so 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. And the 1st through-hole 35 is formed because the bottom faces of these 1st recessed parts 351 and the 2nd recessed part 352 connect. That is, the portion where the first recess 351 and the second recess 352 communicate with each other has a narrowed opening and a constricted shape.

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

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

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

  In the first through hole 35 and the second through hole 36, a first through wiring 311 and a second through wiring 312 are formed as through wirings, respectively. The first through wiring 311 and the second through wiring 312 are filled in 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 the 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 are continuously extended from the first through hole 35 and the second through hole 36 to the second main surface 302 (insulating film 37), and further contact holes. It extends to the inside of 37a and is connected to the terminal of the drive circuit 120.

  A method for manufacturing the first through hole 35 and the second through hole 36, and the first through wiring 311 and the second through wiring 312 will be described in detail later.

  As described above, the first through hole 35 is formed with a constriction having a narrow inner diameter at a portion where the first recess 351 and the second recess 352 communicate with each other. Therefore, the first through hole 35 is formed in the first through hole 35. The movement of the first through wiring 311 in the third direction Z, which is the through direction of the first through hole 35, is restricted by the constriction shape, and is difficult to be displaced. Therefore, when the 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 the difference in the linear expansion coefficient between the drive circuit board 30 and the first through wiring 311. It is possible to suppress the occurrence of displacement and the jumping out of the first main surface 301 or the second main surface 302 of the drive circuit board 30. Incidentally, if 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 substrate 30, the drive circuit substrate. A wiring formed on the surface of the first wiring 30, for example, a part extending on the second main surface 302 of the first through wiring 311, or a metal film 34 connected to the first through wiring 311 on the first main surface 301. Etc. may break. 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 similar to the third through-hole 36 in the second through-hole 36 by the second through-hole 36. The positional deviation with respect to the direction Z can be suppressed, and the disconnection of the wiring can be suppressed.

  In addition, by providing the first through hole 35 with the first concave portion 351 and the second concave portion 352, the first through hole 35 is first compared to the case where the first through hole 35 is formed straight in the third direction Z that is the through direction. The area of the inner wall surface with which the through wiring 311 is in close contact can be increased. Therefore, it is possible to improve the adhesion between the first through-wiring 311 and the inner wall of the first through-hole 35 and to suppress the positional deviation of the first through-wiring 311 with respect to the first through-hole 35.

  Further, the first through wiring 311 formed in the first through hole 35 and the second through wiring 312 formed in the second through hole 36 are formed on the first main surface 301 of the first recesses 351 and 361 and The second recesses 352 and 362 are provided so that the opening of the second main surface 302 is large. For this reason, the electrical resistance values 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 lowered, and the wiring resistance when the piezoelectric actuator 300 is driven at a high frequency. The signal delay due to 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 third opening direction is the narrowest opening area where the first concave portion 351 and the second concave portion 352 communicate with each other. When the first through hole 35 is provided over Z, the electrical resistance value of the first through wiring 311 is increased as compared with the present embodiment. Therefore, when the piezoelectric actuator 300 is driven at a high frequency, a signal delay due to the wiring resistance is caused. It may occur and the print quality may deteriorate.

  In addition, on the first main surface 301 of the drive circuit board 30, the metal film 34 of the first bump 31 and the second bump 32 extends to the center side in the second direction Y. The other ends of the first through wiring 311 and the second through wiring 312 are connected to a portion where the metal film 34 of the first bump 31 and the second bump 32 is extended on the first main surface 301 side of the drive circuit board 30. doing. That is, the first bump 31 and the second bump 32 are electrically connected to the drive circuit 120 by the first through wiring 311 and the second through wiring 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 difficult to change with respect to moisture (moisture), and transmits moisture (moisture). Moist).

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

  Moreover, although mentioned later for details, the 1st penetration wiring 311 and the 2nd penetration wiring 312 can be formed by the 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 to fill.

  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 through 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. 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 this embodiment, the piezoelectric actuator 300 is accommodated 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 by a first through wire 311 and a second through wire 312 that extend through the drive circuit substrate 30 in the third direction Z.

  If the drive circuit 120 has a face-down arrangement, wiring from an external control circuit or the like on the first main surface 301 side of the drive circuit board 30 on the outer side of the holding unit 320 as described in the related art. Must be provided with an input to be connected. That is, the drive circuit board 30 is enlarged on 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 an area for providing the drive circuit 120 with an input unit to which external wiring from an external control circuit or the like is connected because the drive circuit 120 is arranged face up. do not do. Therefore, the region for forming such an input portion is not necessary for the drive circuit board 30, and the drive circuit board 30 can be downsized.

  In the recording head 1 according to the present embodiment, the first through wiring 311 and the second through wiring 312 are extended in the third direction Z that penetrates the drive circuit board 30. Thereby, even if the piezoelectric actuator 300 and the drive circuit 120 are separated inside and outside the holding part 320 by arranging the drive circuit 120 face-up, they can be electrically connected.

  Here, if the wiring for connecting the piezoelectric actuator 300 and the drive circuit 120 is provided without penetrating the drive circuit board 30, the following configuration is obtained. 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 wiring 91 and common wiring 92 are connected to the drive circuit 120 by a wiring such as a bonding wire. In such an aspect, an area for drawing 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 arranged on a horizontal plane (a plane defined by the first direction X and the second direction Y). It will increase in size.

  However, in the recording head 1 according to the present embodiment, since the first through wiring 311 and the second through wiring 312 are extended in the third direction Z that penetrates the drive circuit substrate 30, the recording head 1 is increased in size in the horizontal plane. Can be avoided. Further, in the present embodiment, the first through holes 35 and the second through holes 36 having relatively fine openings can be arranged with high density, so that the size of the recording head 1 can also be reduced in the horizontal direction. be able to.

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

  Between the two rows of piezoelectric actuators 310, a common wiring 92 drawn from the second electrode 80, which is a common electrode, is provided. That is, the second electrodes 80 of the two rows of piezoelectric actuator rows 310 are integrated. For this reason, the second bumps 32 connected to this need only be arranged in a row. Eventually, a total of three bumps including the first bump 31 and the second bump 32 are sufficient, and the width of the drive circuit board 30 in the second direction Y can be reduced.

  If the individual wiring 91 drawn from the first electrode 60, which is an individual electrode, is provided between the two piezoelectric actuator rows 310, the individual wirings 91 cannot be integrated. Therefore, two rows of first bumps 31 corresponding to each piezoelectric actuator row 310 must be arranged between the two rows of piezoelectric actuator rows 310. Then, on the outside of the two rows of piezoelectric actuator rows 310, two rows of second bumps 32 must be arranged corresponding to the respective second electrodes 80. Eventually, 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 bump 32 is provided between the two rows of piezoelectric actuators 310. That is, the second bump 32 is formed with a length equal to or less than the length of the piezoelectric actuator row 310 in the first direction X. As a result, the length of the second bump 32 in the first direction X can be shortened compared to 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. The drive circuit board 30 to be manufactured can also be reduced in size in the first direction X.

  In the recording head 1 according to this 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 this configuration, the electrical connection between the first bump 31 and the second bump 32, the individual wiring 91, and the common wiring 92 can be more reliably maintained.

  Furthermore, as described above, the metal film 34 constituting the second bump 32 is formed so as to be in common contact with all of the plurality of common wirings 92. By using the second bump 32 having such a metal film 34, at least one second through hole 36 for connecting the metal film 34 to the drive circuit 120 and the second through wiring 312 formed in the second through hole 36 are provided. What is necessary is just to form. 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 reduced in size.

  Further, the second through hole 36 and the second through wiring 312 are provided in the drive circuit substrate 30 on both sides of the second bump 32 in the first direction X. Thereby, the difference in distance from each common wiring 92 to the drive circuit 120 is reduced, and variations in voltage drop can be suppressed. Thereby, it is possible to suppress variation in ink ejection characteristics in the piezoelectric actuator 300.

  As described above, in order to suppress variations in voltage drop, a plurality of second through holes 36 and second through wirings 312 may be provided. As described above, these are formed on the drive circuit board 30. It takes an area to do. In the present embodiment, the two second through holes 36 and the second through wiring 312 are arranged on both sides of the second bump 32 in the first direction X. That is, the region 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. Thereby, the variation in 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.

  Further, 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. It overlaps with a part. Specifically, the width of the adhesive layer 39 in the second direction Y extends in a range that does not hinder the connection between the first bump 31 and the individual wiring 91 on the flow path forming substrate 10 side. In other words, in the present embodiment, the adhesive layer 39 has a transverse cross section, that is, a cross-sectional shape in the second direction Y, which has a trapezoidal shape that is wide on the flow path forming substrate 10 side and narrow on the drive circuit board 30 side. . Thus, by bonding the adhesive layer 39 and the first bump 31 in the third direction Z, the adhesive region 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. In the present embodiment, since the bonding area of the adhesive layer 39 is widened to the first bump 31 side so as not to hinder the connection between the first bump 31 and the individual wiring 91, the adhesive layer 39 is connected to the first bump 31. The size can be reduced as compared with the case of spreading to the opposite side. Although not particularly illustrated, the bonding strength between the flow path forming substrate 10 and the drive circuit substrate 30 can be further improved by adopting the same configuration for the adhesive layer 39 in the common wiring 92.

  As shown in FIGS. 1 to 3, a manifold 100 communicating with a plurality of pressure generating chambers 12 is formed in the joined body of the flow path forming substrate 10, the drive circuit substrate 30, the communication plate 15, and the nozzle plate 20. A 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 bonded to the drive circuit board 30 and is also bonded to the communication plate 15 described above. Specifically, the case member 40 has a recess 41 having a depth in which the flow path forming substrate 10 and the drive circuit substrate 30 are accommodated on the drive circuit substrate 30 side. The concave portion 41 has an opening area wider than the surface joined to the flow path forming substrate 10 of the drive circuit substrate 30. The opening surface on the nozzle plate 20 side of the recess 41 is sealed by the communication plate 15 in a state where the flow path forming substrate 10 and the like are accommodated in the recess 41. Further, the case member 40 is formed with 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 portion 42 and the first manifold portion 17 and the second manifold portion 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, resin or metal can be used. Incidentally, the case member 40 can be mass-produced at low cost by molding a resin material.

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

  The case member 40 is provided with an introduction path 44 that communicates with the manifold 100 and supplies ink to each manifold 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, and 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 ink is ejected, the ink is taken in from the liquid storage means in which the ink is stored through 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, according to a signal from the drive circuit 120, a voltage is applied to each piezoelectric actuator 300 corresponding to the pressure generating chamber 12, so that the diaphragm 50 is bent and deformed together with the piezoelectric actuator 300. As a result, the pressure in the pressure generating chamber 12 is increased and ink droplets are ejected from the predetermined nozzle openings 21.

  Here, the manufacturing method of 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 present embodiment.

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

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

  Next, as shown in FIG. 9, the portion that becomes the first through hole 35 in the first insulating film 401 is removed. Specifically, a resist layer 410 is provided on the first main surface 301 and the second main surface 302 of the drive circuit substrate wafer 130, and exposure is performed in a predetermined shape so as to remove a portion that becomes the first through hole 35. . Although not particularly illustrated, the second through hole 36 is formed in the same manner. And the part used as the 1st through-hole 35 and the 2nd through-hole 36 is removed among the 1st insulating films 401 by dry etching. Thereafter, the remaining resist layer 410 is removed.

  Next, as shown in FIG. 10, on both sides of the drive circuit substrate wafer 130, that is, on the portions to be 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 into a predetermined shape by a photolithography method using a photosensitive resist such as a dry film, for example. In this embodiment, the resist layer 410 and the resist layer 411 are separately formed. However, the present invention is not particularly limited to this, and the resist layer 411 is used instead of the resist layer 411 without providing the resist layer 411. You may do it. That is, the resist layer 410 may be used in the next step without being removed.

  Next, as shown in FIG. 11, the first recess 351 is performed by subjecting the drive circuit substrate wafer 130 to sand blasting from the first main surface 301 and the second main surface 302 that are both surfaces via the resist layer 411. And the 1st through-hole 35 which has the 2nd recessed part 352 is formed. That is, the first recess 351 is formed from the first main surface 301 of the drive circuit substrate wafer 130 by sandblasting (first recess forming step). Further, the second concave portion 352 is formed from the second main surface 302 of the drive circuit substrate wafer 130 by sandblasting (second concave portion forming step). In the present embodiment, 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 can be formed by the first concave portion forming step and the second concave portion forming step. In addition, the order of a 1st recessed part formation process and a 2nd recessed part formation process is not specifically limited. Moreover, in the sandblasting method of the drive 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, glass, or the like may be used. After the first through hole 35 and the second through hole 36 are thus formed, the remaining resist layer 411 is removed.

  By forming the first concave portion 351 and the second concave portion 352 in this way by sandblasting, the inner wall of the first concave portion 351 is directed from the first main surface 301 toward the second main surface 302 in the third direction Z. It can be formed of a so-called concave curved surface so that the inclination becomes large. Further, the inner wall of the second recess 352 can be formed as a so-called concave curved surface so that the inclination increases from the second main surface 302 toward the first main surface 301 with respect to the third direction Z.

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

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

  Although not particularly shown, when the first through hole 35 is formed, the second through hole 36 is simultaneously formed in the drive circuit substrate wafer 130. 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 through the resist layer 411 that is the same mask. Further, 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 through the resist layer 411 which is the same mask. Thereby, the number of processes can be reduced and cost can be reduced.

  Next, as shown in FIG. 12, a second insulating film 402 is formed on the drive circuit substrate wafer 130. Specifically, the second insulating film 402 made of, for example, silicon dioxide is formed on the entire surface of the drive circuit substrate wafer 130 by CVD. As a result, the inner surface of the first through hole 35 of the drive circuit substrate wafer 130 that is a silicon wafer is insulated by the second insulating film 402. Although not particularly illustrated, 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 311 a 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 subsequent electroless plating. Next, the first through wiring 311 made of copper is formed on the seed layer by electroless plating. As a result, the first through wiring 311 a 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 also formed in the second through hole 36 in the same manner. Thereafter, it is preferable to perform chemical mechanical polishing (CMP) on both surfaces of the drive circuit substrate wafer 130.

  Here, as described above, 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 have a third direction Z in which the inner wall surface is the through direction. 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 concave portions 351 and 361 and the second concave portions 352 and 362, the seed layer, the first through wiring 311 and the second through hole are formed. The wiring 312 can be formed relatively easily by improving the contact of the first through hole 35 and the second through hole 36 with the inner wall surface. Incidentally, when the inner wall surfaces of the first through hole 35 and the second through hole 36 are provided in a straight line along the third direction Z, that is, in a straight line, the first through hole 35 and the second through hole 36 are provided. There is a risk that the seed layer, the first through wiring 311 and the second through wiring 312 will be attached to the inner wall surface of the inner wall of the seed layer, and the seed layer, the first through wiring 311 and the second through wiring 312 may be poorly formed or peeled off. is there. In the present embodiment, the attachment of the seed layer, the first through wiring 311 and the second through wiring 312 into the first through hole 35 and the second through hole 36 is improved 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, the 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 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. Thereafter, the resist layer 412 is removed.

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

  Next, as shown in FIG. 16, the wiring layer 413 is patterned to form the first through wiring 311 including the first through wiring 311a and the first through wiring 311b. The wiring layer 413 can be patterned by, for example, forming a resist having a predetermined shape on the wiring layer 413 and then etching through the resist. As another manufacturing method of the first through wiring 311, laser patterning using laser light may be performed. Laser patterning enables highly accurate patterning. 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 side of the drive circuit substrate 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 manufacturing method of 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, a first bump 31 and a second bump 32 are formed. Specifically, a resin such as a photosensitive 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, or a thermosetting insulating 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 portion 33. Specifically, an adhesion layer (not shown) is formed by sputtering, and a wiring layer (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 a photolithography method.

  The arrangement of the second bumps 32 on the flow path forming substrate 10 is not particularly limited, but the length between the two piezoelectric actuator rows 310, that is, the length equal to or shorter than the length of the piezoelectric actuator rows 310 in the first direction X. The second bump 32 is preferably formed. As a result, the length of the second bump 32 in the first direction X can be shortened compared to 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. The drive circuit board 30 to be manufactured can also be reduced in size in the first direction X.

  Note that the second bump 32 may be formed in a region on an extension line 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 provided from the second electrode 80 that is a common electrode to a position facing the second bump 32. It may be provided.

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

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

  Next, as shown in FIG. 20, the first electrode 60 is formed on the entire surface of the diaphragm 50 and patterned into a predetermined shape. A control layer for controlling crystal growth of the piezoelectric layer 70 may be formed on the first electrode 60. In the present embodiment, although not particularly illustrated, titanium is used for crystal control 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, the piezoelectric layer 70 and the second electrode 80 are sequentially stacked on the first electrode 60. Here, in this embodiment, a so-called sol-gel in which a so-called sol in which a metal complex is dissolved / dispersed in a solvent is applied, dried, gelled, and further fired at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. The piezoelectric layer 70 is formed using the method. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, using a MOD (Metal-Organic Decomposition) method, a PVD (Physical Vapor Deposition) method such as a sputtering method or a laser ablation method. Also good. That is, the piezoelectric layer 70 may be formed by either a liquid phase method or a gas phase method.

  Next, as shown in FIG. 22, the piezoelectric layer 300 and the second electrode 80 are simultaneously patterned to form the piezoelectric actuator 300. Examples of the patterning of the piezoelectric layer 70 and the second electrode 80 include 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 forming substrate wafer 110. Bonding is performed through the adhesive layer 39. As a result, 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 described above are integrally illustrated as the insulating film 37.

  Next, as shown in FIG. 25, the flow path forming substrate wafer 110 to which the drive 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 generating chamber corresponding to the piezoelectric actuator 300 is obtained by performing anisotropic etching (wet etching) using an alkaline aqueous solution on the flow path forming substrate wafer 110 through the mask film 53. 12 is formed.

  Thereafter, the bonded body obtained by bonding the flow path forming substrate wafer 110 and the drive circuit substrate wafer 130 becomes a single chip size flow path forming substrate 10 and the drive circuit substrate 30 as shown in FIG. After being divided into two, the communication plate 15 in which the nozzle communication passage 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, and the compliance substrate 45 are sequentially joined. Further, the case member 40 is bonded to the drive circuit board 30 and the communication plate 15 to obtain the recording head 1 of the present embodiment.

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

  In addition, the first concave portions 351 and 361 and the second concave portions 352 and 362 constituting 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 with a relatively small opening area and high density. Accordingly, the horizontal size of the drive circuit board 30 can be reduced, and the recording head 1 can be reduced in size.

  Moreover, the 1st through-hole 35 and the 2nd through-hole 36 are formed by the sandblast method by forming the 1st recessed part 351,361 and the 2nd recessed part 352,362 which comprise the 1st through-hole 35 and the 2nd through-hole 36. Compared to forming by ICP, the processing speed can be increased and processing can be performed in a short time. Incidentally, when forming a through hole by ICP, it takes a processing time in proportion to the opening area of the through hole. In addition, a sandblasting apparatus that performs the sandblasting method is less expensive than an etching apparatus that performs ICP processing, and thus can reduce capital investment. Accordingly, the manufacturing cost of the first through wiring 311 and the second through wiring 312 can be reduced.

  Furthermore, the first through holes 35 and the second through holes 36 are formed by sandblasting the first concave portions 351 and 361 and the second concave portions 352 and 362 constituting the first through holes 35 and the second through holes 36. The first through hole 35 and the second through hole 36 can be formed in the relatively thick drive circuit board 30 as compared with the case of forming by laser processing. That is, in the formation of the through hole by laser processing, the thickness of the drive circuit board 30 to be processed is limited, and when the through hole is formed in the relatively thick drive circuit board 30 by laser processing, the opening area is reduced. Wide through holes can only be formed at low density. In the present embodiment, 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 are formed by a sandblast method, so that the driving is relatively thick compared to laser processing. It becomes possible to form the first through hole 35 and the second through hole 36 having relatively small openings in the circuit board 30 with high density. In addition, a sand blasting apparatus that performs the sand blasting method is less expensive than a laser processing apparatus that performs laser processing, and thus can reduce capital investment. Accordingly, 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 by a sandblasting method, generation of burrs on the surface of the drive circuit board 30 generated when laser processing, ICP, drilling, or the like is performed, Contamination due to adhesion of debris can be suppressed. Incidentally, when burrs are formed on the surface of the drive circuit board 30, when the drive circuit board 30 is joined to another member, the drive circuit board 30 and the other member are pressed and brought into contact with each other. There is a risk that stress concentrates on the burrs and breaks such as cracks occur starting from the burrs. In the present embodiment, the generation of burrs on the surface of the drive circuit board 30 can be suppressed, and breakage such as cracks can be suppressed. In general, during laser processing, adhesion of debris and the like is suppressed by forming a protective film on the surface of the substrate. However, debris adheres to the protective film, and debris also forms at the interface between the substrate and the protective film. Therefore, debris is present on the substrate surface when the protective film is peeled off.

  Furthermore, the first through hole 35 is provided with the first concave portion 351 and the second concave portion 352, so that the first through hole 35 is formed in the first direction as compared with the case where the first through hole 35 is formed straight in the third direction Z. The area of the inner wall surface with which the through wiring 311 is in close contact can be increased. Therefore, it is possible to improve the adhesion between the first through-wiring 311 and the inner wall of the first through-hole 35 and to suppress the positional deviation of the first through-wiring 311 with respect to the first through-hole 35.

  Further, by forming the first concave portions 351 and 361 and the second concave portions 352 and 362 by sandblasting, so-called roughening is performed in which irregularities are formed on the surface of the inner wall surface to roughen 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 a so-called constriction in which an opening is narrowed at a portion where the first recesses 351 and 361 and the second recesses 352 and 362 communicate with each other. For this reason, when the temperature change occurs, the first through-wiring 311 and the second through-wiring 312 are in the first due to the difference in coefficient of linear expansion between the drive circuit board 30 and the first through-wiring 311 and the second through-wiring 312. A positional shift in the third direction Z with respect to the through-hole 35 and the second through-hole 36 can be suppressed, and jumping out from one of the first main surface 301 and the second main surface 302 can be suppressed. Accordingly, the positional 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 is suppressed, and the disconnection of the wiring on the first main surface 301 and the second main surface 302 is prevented. Can be suppressed. In other words, in the present embodiment, the contact area between the first through hole 35 and the second through hole 36 and the first through wiring 311 and the second through wiring 312 is increased to improve the adhesion and the first through hole 35. In addition, at least a part of the second through hole 36 is formed by sandblasting to be roughened to improve the adhesion, and further, a so-called constriction with a narrow opening at the center is formed, whereby the first through wiring 311 and A positional shift in the penetration direction of the second through wiring 312 with respect to the first through hole 35 and the second through hole 36 can be synergistically suppressed.

  In the manufacturing method of the recording head 1 according to the present embodiment described above, the drive circuit 120 is provided with a face-up arrangement, so that the drive circuit 120 is provided with an input unit to which external wiring from an external control circuit or the like is connected. No need for space for. Therefore, the region for forming such an input portion is not necessary 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 are extended in the third direction Z penetrating the drive circuit board 30, the through wiring is shortened and the drive circuit board 30 is enlarged in a horizontal plane. You can avoid that. In particular, in the present embodiment, the first concave portions 351 and 361 and the second concave portions 352 and 362 constituting 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 provided. By forming by the sand blasting method, the first through holes 35 and the second through holes 36 can be formed with high density at high density. Therefore, a space for forming the first through wiring 311 and the second through wiring 312 can be omitted, and the drive circuit board 30 can be downsized.

  As described above, according to the method of 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, the recording head 1 that can cope with the high density of the nozzle openings 21 and can discharge ink at a high density can be manufactured.

  In the present embodiment, the first bump 31 and the second bump 32 and the drive circuit board 30 on which the first through wiring 311 and the second through wiring 312 are formed in advance are 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. As a result, after the flow path forming substrate 10 and the drive circuit substrate 30 are joined, the manufacturing process is compared with the case where the connection wiring is connected to the lead electrode drawn out of the holding unit 320 by film formation and lithography. It can be simplified.

  In the present embodiment, the first concave portion 351 and the second concave portion 352 are formed by the sandblasting 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 first recess 351, a second recess 352, and a communication hole 353 that communicates the first recess 351 and the second recess 352. Good. Here, the manufacturing method of the 1st through-hole 35 which has such a communicating hole 353 is demonstrated with reference to FIGS. 29 to 32 are principal part cross-sectional views showing a method for manufacturing a recording head.

  As shown in FIG. 29, the first concave portion 351 and the second concave portion 352 are formed on the drive circuit substrate wafer 130 by the sandblasting method by the same method as in FIG. At this time, the first recess 351 and the second recess 352 are communicated.

  Next, as shown in FIG. 30, the innermost protruding portion 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 1st through-hole 35 which has the 1st recessed part 351 and the 2nd recessed part 352 formed by the sandblasting method, and the communicating hole 353 formed by laser processing can be formed. Of course, the second through hole 36 can also be formed by a similar process.

  Thus, even if the opening area of the 1st recessed part 351 and the 2nd recessed part 352 is made further smaller by comprising the 1st through-hole 35 by the 1st recessed part 351, the 2nd recessed part 352, and the communicating hole 353, the 1st recessed part 351 and the second recess 352 can be reliably communicated with each other. 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 is thick, the first recess 351 and the second recess 352 having a small opening cannot be communicated 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 be formed in communication with each other. Furthermore, 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 communicated. Accordingly, the cross section of the first through wiring 311 formed in the first through hole 35 can be increased to 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.

  Further, the first recess 351 and the second recess 352 are formed by sandblasting, and the communication hole 353 is formed by laser processing at a position away from the surface of the drive circuit board 30. Therefore, burrs and debris generated by laser processing are formed. Can be prevented 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 if it is the 1st through-hole 35 which has the communicating hole 353, generation | occurrence | production of a burr | flash or a debris is suppressed and the destruction of the drive circuit board 30 by this burr | flash or a debris and the other member joined to this is suppressed. Can do.

  Such a 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 communicated with each other when the first recess 351 and the second recess 352 are formed by the sandblast method. it can.

  That is, as shown in FIG. 31, the first recess 351 and the second recess 352 are formed on both sides of the drive circuit substrate wafer 130 by the sandblast method. At this time, the first recess 351 and the second recess 352 are formed to a depth that does not allow communication. Next, as shown in FIG. 32, the bottom surface of the first recess 351 or the second recess 352 is irradiated with laser light to perform laser processing, whereby a communication hole 353 that connects the first recess 351 and the second recess 352 is provided. Is formed (communication hole forming step). It is possible to suppress the generation of burrs and debris on the surface of the drive circuit board 30 also by such a method of forming the communication hole 353. 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. Is possible.

(Embodiment 2)
FIG. 33 is a cross-sectional view of main parts of a recording head according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member same as embodiment mentioned above, and the overlapping description is abbreviate | 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 that communicates with the first recess 351, the second recess 352, and the second recess 352. And a fourth recess 355.

  Here, the third recess 354 and the fourth recess 355 are provided between the first recess 351 and the second recess 352, and in the present embodiment, the bottom surfaces of the third recess 354 and the fourth recess 355 are provided. They communicate directly with each other.

  Similar to the first recess 351, the third recess 354 has a larger inclination from the first main surface 301 toward the second main surface 302 with respect to the third direction Z, which is the penetration direction of the first through hole 35. It is formed with a concave curved surface.

  In addition, 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.

  Similar to 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 that is the penetration direction of the first through hole 35. It is formed with a concave curved surface.

  Further, 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.

  A first through wire 311 is formed in the first through hole 35 constituted by the first recess 351, the second recess 352, the third recess 354, and the fourth recess 355.

  Here, the manufacturing method of the 1st through-hole 35 of this embodiment is demonstrated with reference to FIG.34 and FIG.35. 34 and 35 are cross-sectional views illustrating the main part of the recording head manufacturing method 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 drive circuit substrate wafer 130 by the sandblast method by the same method as in FIG. At this time, the first recess 351 and the second recess 352 do not communicate with each other. Then, by continuing the sandblasting method, as shown in FIG. 35, a third recess 354 and a fourth recess 355 are formed (a third recess forming step and a fourth recess forming step). That is, in the sandblasting method, when a predetermined depth is reached, the particles are concentrated at the center and the opening is formed in a stepped shape. Thereby, the 3rd recessed part 354 and the 4th recessed part 355 are formed. That is, the third recess 354 and the fourth recess 355 are formed when the first through hole 35 having a small opening is formed in the drive circuit substrate 30 having a relatively large thickness by the sandblast method.

  In addition, although a 1st recessed part formation process and a 3rd recessed part formation process, a 2nd recessed part formation process, and a 4th recessed part formation process are performed by another process, the order is not specifically limited.

  The third recess 354 and the fourth recess 355 can also be formed by gradually expanding the opening of the resist layer 411 which is a mask used when forming the first recess 351 and the second recess 352. it can. That is, for example, after forming the opening for forming the third recess 354 and the fourth recess 355 in the resist layer 411 and performing the sand blasting method, after forming the recess of a predetermined depth, the opening of the resist layer 411 is formed. Is expanded to the size of the first recess 351 and the second recess 352, and the sandblast method is performed. Thereby, it can form deeply with the shape before opening opening, and can form the recessed part which has a level | step difference.

  As described above, the first through hole 35 is formed by the first concave portion 351, the second concave portion 352, the third concave portion 354, and the fourth concave portion 355, so that the opening of the first through hole 35 is not increased. 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.

  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 communicate with each other through the communication hole 353. Such a communication hole 353 may be formed by laser processing after the third recess 354 and the fourth recess 355 communicate with each other as in the first embodiment described above, and the third recess 354 and the fourth recess 355. Alternatively, the communication hole 353 may be formed by laser processing from a state in which the communication is not performed.

  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. The thick drive circuit board 30 can be formed with high density.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic composition 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, but the present invention is not necessarily limited to such a mode. 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 bump 32 is provided between the two rows of piezoelectric actuators 310. However, the present invention is not limited to such a mode, and the drive circuit board 30 or the flow path forming board 10 is not limited thereto. Can be provided at any position. For example, the second bump 32 may be provided in a region on the extension line of the piezoelectric actuator row 310. In other words, 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.

  Further, in the first and second embodiments, one drive circuit 120 is provided for the two rows of piezoelectric actuators 300, but the present invention is not particularly limited thereto. For example, the drive circuit 120 may be provided for each row of the piezoelectric actuators 300 in one row.

  Further, although the adhesive layer 39 is provided on both sides in the second direction Y for each of the three rows of the first bump 31 and the second bump 32, it is not particularly limited thereto. It suffices to be provided at least on both sides of the first bump 31.

  Furthermore, in the first and second embodiments described above, one drive circuit board 30 is provided for one flow path forming board 10, but the present invention is not particularly limited thereto. For example, the drive circuit board 30 may be provided for each piezoelectric actuator row 310. That is, two drive circuit substrates 30 may be provided for one flow path forming substrate 10.

  In the first and second embodiments, the common wiring 92 is drawn from the second electrode 80 that is a common electrode of the two rows of piezoelectric actuator rows 310. That is, the common wiring 92 is a wiring common to the two rows of piezoelectric actuator rows 310, but is not limited to such a mode. For example, the common wiring 92 may be provided from the second electrode 80 of the piezoelectric actuator array 310. That is, the common wiring 92 may be individually drawn from one piezoelectric actuator row 310 and the other piezoelectric actuator row 310, and each common wiring 92 may be in contact with the second bump 32. The common wiring 92 is preferably common to the two rows of piezoelectric actuator rows 310. By using the common wiring 92 that is common to the two piezoelectric actuator rows 310, the second through-wiring 312 and the second through-hole 36 that are connected via the second bump 32 are used rather than the individual common wiring 92. The number can be reduced and the size can be reduced.

  Furthermore, in the first and second embodiments, the second bump 32 is a metal that is long in the first direction X so as to cover the core portion 33 on the core portion 33 extending along the first direction X. Although the film 34 is formed, the present invention is not limited to such a mode. 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 this mode, and the position and the number are arbitrary. .

  Further, in the first and second embodiments described above, the driving element that causes a pressure change in the pressure generating chamber 12 has been described using the thin film type piezoelectric actuator 300. However, the present invention is not particularly limited thereto. A thick film type piezoelectric actuator formed by a method such as affixing, or a longitudinal vibration type piezoelectric actuator in which piezoelectric materials and electrode forming materials are alternately stacked to expand and contract in the axial direction can be used. Also, as a driving element, a heating element is arranged in the pressure generating chamber, and a droplet is discharged from the nozzle opening by a bubble generated by heat generation of the heating element, or static electricity is generated between the diaphragm and the electrode. A so-called electrostatic actuator that discharges liquid droplets from the nozzle openings by deforming the diaphragm by electrostatic force 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 the ink jet recording apparatus I, the recording head 1 is provided with a cartridge 2 constituting an ink supply means in a detachable manner, and a carriage 3 on which the recording head 1 is mounted is a carriage attached to the apparatus main body 4. The shaft 5 is provided so as to be movable in the axial direction.

  Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), 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 conveyance roller 8 as a conveyance means, and a recording sheet S which is a recording medium such as paper is conveyed by the conveyance roller 8. Note that the conveyance means for conveying the recording sheet S is not limited to the conveyance roller, and may be a belt, a drum, or the like.

  In the inkjet recording apparatus I described above, the recording head 1 is mounted on the carriage 3 and moved in the main scanning direction. However, the present invention is not particularly limited thereto. For example, the recording head 1 is fixed, The present invention can also 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.

  In the above-described example, the ink jet recording apparatus I has a configuration in which the cartridge 2 that is a liquid storage unit is mounted on the carriage 3. However, the invention is not particularly limited thereto, and for example, a liquid storage unit such as an ink tank is used. The storage unit and the recording head 1 may be connected to each other via a supply pipe such as a tube by being fixed to the apparatus main body 4. Further, the liquid storage means may not be mounted on the ink jet recording apparatus.

  Furthermore, the present invention is intended for a wide range of general heads, and is used, for example, in the manufacture of recording heads such as various 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 ejection head used for electrode formation such as a color material ejection head, an organic EL display, and an FED (field emission display), a bioorganic matter ejection head used for biochip production, and the like.

  The present invention is widely intended for MEMS devices, and can be applied to MEMS devices other than recording heads. 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 The IR device used, the ferroelectric memory using a ferroelectric element, etc. are also included in the MEMS device. By using the through wiring with reduced wiring resistance according to the present invention in the MEMS device, it becomes possible to detect a minute current.

  Furthermore, the present invention is widely intended for through wiring, and can also be applied to through wiring other than MEMS devices.

  DESCRIPTION OF SYMBOLS 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.

Claims (14)

A through-hole and a through-wiring formed in the through-hole,
The through hole is
A first recess formed at one end of the through hole;
A second recess formed at the other end opposite to the one end of the through hole;
Have
The inclination of the inner wall of the first recess increases from the one end to the other end with respect to the penetrating direction of the through hole,
The through wiring according to claim 1, wherein an inclination of an inner wall of the second concave portion increases from the other end toward the one end with respect to a penetrating direction of the through hole. The through hole is
A third recess communicating with the first recess;
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,
2. The through wiring according to claim 1, wherein an inclination of the second recess on the fourth recess side is larger than an inclination of the fourth recess on the second recess side.   The through wiring according to claim 1, wherein the first recess and the second recess are communicated with each other through a communication hole.   The through wiring according to claim 2, wherein the third recess and the fourth recess are communicated with each other through a communication hole.   5. The through wiring according to claim 3, wherein an opening diameter of each of the first recess and the second recess is larger than a maximum diameter of the communication hole. A MEMS device that detects a signal from the outside and changes a current value before and after detection,
A part of the wiring through which the current passes is the through wiring according to claim 1.   A liquid ejecting head comprising the through wiring according to claim 1. A method for manufacturing a through-wiring formed in a through-hole,
A first recess forming step of forming a first recess in which the inner wall of one end of the through hole is inclined more toward the other end with respect to the through direction of the through hole;
A second recess forming step in which an inner wall of the other end of the through-hole forms a second recess whose inclination increases toward the one end;
Forming a through wiring in the through hole, and
The method for producing a through wiring, wherein the first concave portion forming step and the second concave portion forming step use a sandblasting method. The first recess forming step includes a third recess forming step of forming a third recess communicating with the first recess;
9. The method for manufacturing a through-hole wiring according to claim 8, wherein the second recess forming step includes a fourth recess forming step of forming a fourth recess communicating with the second recess.   The method of manufacturing a through wiring according to claim 8, further comprising a communication hole forming step of forming a communication hole connecting the first recess and the second recess.   The method of manufacturing a through wiring according to claim 9, further comprising a communication hole forming step of forming a communication hole connecting the third recess and the fourth recess.   The method for manufacturing a through wiring according to any one of claims 8 to 11, 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 claim 8.   A method for manufacturing a liquid jet head, comprising the method for manufacturing a MEMS device according to claim 13.

Images