JP2019089309A - Mems device, liquid jet head, liquid jet device, and manufacturing method of the mems device - Google Patents

Abstract

To provide an MEMS device (a liquid jet head), and a manufacturing method of the same which can supply a drivable signal to a functional element stably, and can suppress deterioration of the functional element by bonding two substrate with an adhesive.SOLUTION: Adhesives 61, 62, 63 adhere a first substrate 33 and a second substrate 29. A first space structured as a closed space, which includes electrodes 67, 68, an individual electrode 37, a common electrode 38, and a bump electrode 40, and a piezoelectric element 32 and is shut off from the atmosphere by the first substrate 33, the second substrate 29, and the adhesives 61, 62, is arranged in a space between the first substrate 33 and the second substrate 29. A second space, which does not include any of the electrodes 67, 68, the individual electrode 37, the common electrode 38, the bump electrode 40, and the piezoelectric element 32, and communicates with the atmosphere by a through hole 46 penetrating at least one of the first substrate 33 and the second substrate 29, is arranged in a space between the first substrate 33 and the second substrate 29.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a MEMS device, a liquid jet head which is an example of a MEMS device, a liquid jet apparatus including the liquid jet head, and a method of manufacturing the MEMS device.

  An ink jet recording head, which is an example of a micro electro mechanical systems (MEMS) device, includes a flow path forming substrate in which a pressure generating chamber for storing liquid is formed, and a functional element provided on one side of the flow path forming substrate The piezoelectric element is driven to generate a pressure change in the liquid in the pressure generating chamber by driving the functional element (piezoelectric element), and the liquid droplets are ejected from the nozzle communicated with the pressure generating chamber.

  As a piezoelectric element used in such an ink jet recording head, a thin film type formed on a flow path forming substrate by film formation and photolithography has been proposed. The use of a thin film piezoelectric element makes it possible to arrange the piezoelectric elements at a high density, but makes it difficult to electrically connect the piezoelectric elements arranged at a high density to the drive circuit.

  For example, an ink jet recording head described in Patent Document 1 includes a flow path forming substrate provided with a pressure generation chamber and a piezoelectric element, and a drive circuit substrate provided with a drive circuit for driving the piezoelectric element, and a drive circuit. And the piezoelectric element are electrically connected via bumps provided on the drive circuit substrate. Furthermore, a plurality of bumps are disposed in the peripheral region of the piezoelectric element, and a sealing material (adhesive) is filled between the plurality of bumps.

By using the bumps for connection between the drive circuit and the piezoelectric element, it is possible to easily electrically connect the piezoelectric element and the drive circuit arranged at high density. Furthermore, the adhesive is disposed between the flow path forming substrate and the drive circuit substrate, and shields the piezoelectric element from the atmosphere to protect it from moisture. However, when the adhesive is heated to a high temperature in order to cure the adhesive, the gas in the space which seals the piezoelectric element (hereinafter referred to as a sealed space) expands and the drive circuit and the piezoelectric element There is a risk of misalignment.
Therefore, in order to prevent the pressure rise in the sealed space, a through hole for releasing the sealed space to the atmosphere may be provided in the drive circuit substrate.

JP, 2014-51008, A JP, 2009-117544, A

  However, there is a possibility that liquid or gas may intrude through the open hole of the drive circuit substrate to the atmosphere, and the moisture resistance to the drive circuit or the piezoelectric element (functional element) may be insufficient.

  Furthermore, the same problem exists in MEMS devices other than ink jet recording heads, for example, SAW (Surface Acoustic Wave) oscillators. The SAW oscillator described in Patent Document 2 is an example of a MEMS device, and includes a semiconductor substrate provided with a SAW element (surface acoustic wave element (functional element)) or a bump and a sealing substrate, and high density mounting by the bump The surface oxidation of the SAW element (functional element) and the bonding with water molecules are suppressed by the sealing member (adhesive agent) which joins the semiconductor substrate and the sealing substrate. For example, two substrates can be joined by an adhesive, and a drivable signal can be stably supplied to the functional element, and deterioration of the functional element can be suppressed. If the SAW oscillator has a through hole released to the atmosphere, there is a possibility that the suppression of the surface oxidation of the SAW element (functional element) and the bonding with water molecules may be insufficient.

  The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following modes or application examples.

  A MEMS device according to this application example includes a first substrate having a first electrode and a second electrode, and the first electrode and the second electrode are stacked and arranged between the first substrate and the first substrate. A second substrate, a third electrode disposed between the first substrate and the second substrate and electrically connecting the first electrode and the second electrode, the first substrate and the second substrate And an adhesive for bonding the first substrate and the second substrate, wherein the first element is disposed in a space between the first substrate and the second substrate. An electrode, the second electrode, the third electrode, and the piezoelectric element, and the first substrate, the second substrate, and a closed space shielded from the atmosphere by the adhesive; A first space, and a space between the first substrate and the second substrate, the first electrode; A second space which does not include any of the electrode, the third electrode, and the piezoelectric element, and which is in communication with the atmosphere by a through hole penetrating at least one of the first substrate and the second substrate; It is characterized in that it is formed to be arranged.

  A liquid jet head according to this application example includes the MEMS device described in the application example.

  The liquid ejecting apparatus according to this application example includes the liquid ejecting head described in the above application example.

  A method of manufacturing a MEMS device according to the application example includes a first substrate having a first electrode, a second electrode, and the first electrode and the second electrode between the first substrate and the first substrate. A second substrate to be stacked, a third electrode disposed between the first substrate and the second substrate, and electrically connecting the first electrode and the second electrode, and the first substrate A manufacturing method comprising: a piezoelectric element disposed between the second substrate and an adhesive for bonding the first substrate and the second substrate, wherein the first substrate and the second substrate The first space in which the first electrode, the second electrode, the third electrode, and the piezoelectric element are contained is the space between the first substrate, the second substrate, and the adhesive. In the space between the first substrate and the second substrate, it is configured as a closed space shielded from the atmosphere A second space not including any of the first electrode, the second electrode, the third electrode, and the piezoelectric element is a through hole penetrating at least one of the first substrate and the second substrate. Forming and communicating with the atmosphere, and heat curing the adhesive.

FIG. 1 is a schematic view showing the configuration of a liquid ejecting apparatus (printer) according to a first embodiment. FIG. 1 is a schematic cross-sectional view showing the configuration of a liquid jet head (recording head) according to a first embodiment. FIG. 1 is a schematic cross-sectional view showing the configuration of an electronic device according to Embodiment 1. FIG. 2 is a schematic plan view seen through a first substrate showing the configuration of a liquid jet head (recording head) according to the first embodiment. 7 is a process flow showing a method of manufacturing a liquid jet head (recording head) according to the first embodiment. The schematic sectional drawing which shows the state after passing through step S1. The schematic sectional drawing which shows the state after passing through step S2. The schematic sectional drawing which shows the state after passing through step S21. The schematic sectional drawing which shows the state after passing through step S22. The schematic sectional drawing which shows the state after passing through step S3. FIG. 6 is a schematic cross-sectional view showing the configuration of a liquid jet head (recording head) according to a second embodiment. FIG. 7 is a schematic cross-sectional view showing the configuration of a liquid jet head (recording head) according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Such an embodiment shows one aspect of the present invention, does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Further, in the following drawings, the scale of each layer or each part is made different from the actual scale in order to make each layer or each part recognizable in the drawing.

(Embodiment 1)
"Overview of Printer"
FIG. 1 is a schematic view showing the configuration of a liquid ejecting apparatus (hereinafter, referred to as a printer) according to the first embodiment. First, with reference to FIG. 1, an outline of a printer 1 which is an example of the “liquid ejecting apparatus” will be described.
The printer 1 according to the present embodiment is an ink jet recording apparatus that ejects an ink, which is an example of “liquid”, to a recording medium 2 such as recording paper, and records (prints) an image or the like on the recording medium 2.

As shown in FIG. 1, the printer 1 includes a recording head 3, a carriage 4 to which the recording head 3 is attached, a carriage moving mechanism 5 for moving the carriage 4 in the main scanning direction, and a transport mechanism for transporting the recording medium 2 in the subscanning direction. 6 and so on. Here, the above-described ink is stored in an ink cartridge 7 as a liquid supply source. The ink cartridge 7 is detachably attached to the recording head 3.
The recording head 3 is a "MEMS (Micro Electro Mechanical Systems) device", and constitutes an example of a "liquid jet head". Furthermore, the ink cartridge may be disposed on the main body side of the printer, and the ink may be supplied to the recording head 3 from the ink cartridge through the ink supply tube.

  The carriage moving mechanism 5 includes a timing belt 8 and is driven by a pulse motor 9 such as a DC motor. When the pulse motor 9 operates, the carriage 4 is guided by a guide rod 10 installed in the printer 1 and reciprocates in the main scanning direction (the width direction of the recording medium 2). The position of the carriage 4 in the main scanning direction is detected by a linear encoder (not shown) which is a type of position information detection means. The linear encoder transmits the detection signal, that is, an encoder pulse to the control unit of the printer 1.

  Further, in an end area outside the recording area in the movement range of the carriage 4, a home position serving as a base point of scanning of the carriage 4 is set. At this home position, a cap 11 for sealing the nozzles 22 (see FIG. 2) formed on the nozzle surface (the nozzle plate 21 (see FIG. 2)) of the recording head 3 in order from the end side A wiping unit 12 for wiping is disposed.

"Overview of the recording head"
FIG. 2 is a schematic cross-sectional view showing the configuration of the liquid jet head (recording head 3) according to the present embodiment.
Next, the outline of the recording head 3 will be described with reference to FIG.
As shown in FIG. 2, the recording head 3 includes a flow path unit 15, an electronic device 14, and a head case 16. In the recording head 3, the flow path unit 15 and the electronic device 14 are attached to the head case 16 in a stacked state.
Hereinafter, the direction in which the flow path unit 15 and the electronic device 14 are stacked will be described as the vertical direction.

  The head case 16 is a box-like member made of a synthetic resin, and a reservoir 18 for supplying ink to each pressure generation chamber 30 is formed therein. The reservoirs 18 are spaces in which a common ink is stored in a plurality of pressure generating chambers 30 arranged in parallel, and two reservoirs 18 are formed corresponding to the rows of the pressure generating chambers 30 arranged in parallel. An ink introduction path (not shown) for introducing the ink from the ink cartridge 7 side into the reservoir 18 is formed above the head case 16.

  The flow path unit 15 joined to the lower surface of the head case 16 has a communication substrate 24 and a nozzle plate 21. The communication substrate 24 is a plate made of silicon, and in the present embodiment, the communication substrate 24 is manufactured from a silicon single crystal substrate in which the crystal plane orientation of the surface (upper surface and lower surface) is (110). In the communication substrate 24, the common liquid chamber 25 communicated with the reservoir 18 and in which the common ink is stored in each pressure generation chamber 30, and the ink from the reservoir 18 via the common liquid chamber 25 are separately supplied to each pressure generation chamber 30. The individual communication passages 26 for supplying the air are formed by etching. The common liquid chamber 25 is a long hollow portion along the nozzle row direction, and is formed in two rows corresponding to the rows of the pressure generating chambers 30 arranged in parallel in two rows. The common liquid chamber 25 is recessed from the lower surface side of the communication substrate 24 toward the upper surface toward the upper surface side of the first liquid chamber 25 a penetrating the thickness direction of the communication substrate 24 and halfway to the thickness direction of the communication substrate 24. And a second liquid chamber 25b formed with the thin plate portion left on the side. A plurality of individual communication paths 26 are formed in the thin plate portion of the second liquid chamber 25 b along the direction in which the pressure generating chambers 30 are arranged corresponding to the pressure generating chambers 30. The individual communication passage 26 communicates with one end of the corresponding pressure generation chamber 30 in the longitudinal direction in a state where the communication substrate 24 and the second substrate 29 (described later) are joined.

  Further, at positions corresponding to the respective nozzles 22 of the communication substrate 24, a nozzle communication passage 27 which penetrates the thickness direction of the communication substrate 24 is formed. That is, a plurality of nozzle communication paths 27 are formed along the nozzle row direction corresponding to the nozzle row. The pressure generating chamber 30 and the nozzle 22 are communicated with each other by the nozzle communication passage 27. The nozzle communication passage 27 is provided at the other end (the end opposite to the individual communication passage 26) in the longitudinal direction of the corresponding pressure generation chamber 30 in a state where the communication substrate 24 and the second substrate 29 are joined. It is communicated.

  The nozzle plate 21 is a silicon substrate (for example, a silicon single crystal substrate) joined to the lower surface (surface opposite to the second substrate 29 side) of the communication substrate 24. In the present embodiment, the nozzle plate 21 seals the opening on the lower surface side of the space to be the common liquid chamber 25. Further, in the nozzle plate 21, a plurality of nozzles 22 are provided linearly (in a row). In the present embodiment, two nozzle rows are formed corresponding to the rows of the pressure generating chambers 30 formed in two rows. The plurality of nozzles 22 (nozzle rows) arranged in parallel have a pitch (for example, 600 dpi) corresponding to the dot formation density from the nozzles 22 on one end side to the nozzles 22 on the other end side, in the sub scanning direction orthogonal to the main scanning direction. Are provided at equal intervals along the.

  The electronic device 14 is a thin plate-like piezoelectric device that functions as an actuator that causes a pressure change in the ink in each pressure generation chamber 30. That is, in the electronic device 14, the pressure in the ink in each pressure generation chamber 30 is changed, and the ink is ejected from the nozzles 22 communicated with each pressure generation chamber 30. The electronic device 14 has a configuration in which the second substrate 29, the adhesives 61, 62, 63, the first substrate 33, and the drive IC 34 are sequentially stacked and unitized. In other words, in the electronic device 14, the second substrate 29 and the first substrate 33 having the drive IC 34 are bonded by the adhesives 61, 62, 63.

The second substrate 29 is stacked on the first substrate 33, and includes a pressure generation chamber formation substrate 28, a diaphragm 31, an individual electrode 37, a common electrode 38, and a piezoelectric element 32.
The pressure generating chamber forming substrate 28 is a hard plate material made of silicon, and is manufactured from a silicon single crystal substrate in which the crystal plane orientation of the surface (upper surface and lower surface) is (110). The pressure generating chamber forming substrate 28 has a through hole 30 a forming the pressure generating chamber 30. The through hole 30a is formed by anisotropically etching a silicon single crystal substrate of plane orientation (110) in the thickness direction. The through hole 30 a is a space (empty portion) that forms the pressure generation chamber 30.

  The diaphragm 31 is a thin film-like member having elasticity, and is formed on the upper surface (surface opposite to the communication substrate 24 side) of the pressure generating chamber forming substrate 28. The diaphragm 31 is composed of an elastic film made of silicon oxide formed on the upper surface of the pressure generation chamber forming substrate 28 and an insulating film made of zirconium oxide formed on the elastic film. The diaphragm 31 seals the upper opening of the through hole 30 a of the pressure generating chamber forming substrate 28.

  Further, the lower opening of the through hole 30 a of the pressure generation chamber formation substrate 28 is sealed by the communication substrate 24. Then, the through hole 30 a (empty portion) sealed by the diaphragm 31 and the communication substrate 24 becomes the pressure generating chamber 30. The pressure generating chambers 30 are formed in two rows corresponding to the nozzle rows formed in two rows. The pressure generating chamber 30 is an empty portion (space) elongated in the direction orthogonal to the nozzle row direction, and the separate communication passage 26 is in communication with one end in the longitudinal direction, and the nozzle series is connected to the other end. The passage 27 is in communication.

  The area of the diaphragm 31 corresponding to the pressure generating chamber 30 (the area where the diaphragm 31 and the pressure generating chamber forming substrate 28 are not in contact) is a direction in which the diaphragm 31 moves away from the nozzle 22 with the displacement of the piezoelectric element 32. Or it functions as a displacement part displaced to the direction which adjoins. That is, a region (a region where the diaphragm 31 and the pressure generation chamber forming substrate 28 are not in contact) corresponding to the pressure generation chamber 30 in the diaphragm 31 is a drive region 35 where displacement of the diaphragm 31 is permitted. On the other hand, the area out of the pressure generating chamber 30 in the diaphragm 31 (the area in which the diaphragm 31 and the pressure generating chamber forming substrate 28 are in contact) becomes a non-driving area 36 in which the displacement of the diaphragm 31 is inhibited.

  In the drive region 35, the piezoelectric element 32 is formed on the surface of the diaphragm 31 opposite to the pressure generating chamber forming substrate 28 side. Specifically, the lower electrode layer (individual electrode), the piezoelectric layer, and the upper electrode layer (common electrode) are sequentially stacked on the surface of the drive region 35 opposite to the pressure generating chamber forming substrate 28 side of the diaphragm 31. The piezoelectric element 32 is formed. The piezoelectric element 32 is a so-called deflection mode piezoelectric element, and causes the diaphragm 31 to be bent and deformed. When an electric field corresponding to the potential difference between the lower electrode layer and the upper electrode layer is applied to the piezoelectric layer, the piezoelectric element 32 is displaced in the direction away from or in the vicinity of the nozzle 22.

The lower electrode layer constituting the piezoelectric element 32 is extended to the non-driving area 36 outside the piezoelectric element 32 to form an individual electrode 37, and is electrically connected to the corresponding bump electrode 40 (described later). In the lower electrode layer of the piezoelectric element 32 extended to the non-driving region 36, the portion in contact with the bump electrode 40 becomes the individual electrode 37, and the portion between the portion forming the piezoelectric element 32 and the portion forming the individual electrode 37 is It becomes individual wiring.
The individual electrode 37 is an example of the “second electrode”, and the bump electrode 40 is an example of the “third electrode”.

The upper electrode layer constituting the piezoelectric element 32 is extended to the non-driving region 36 between the columns of the piezoelectric element 32 to form a common electrode 38, and is electrically connected to the corresponding bump electrode 40. In the upper electrode layer of the piezoelectric element 32 extended to the non-driving region 36, the portion in contact with the bump electrode 40 is the common electrode 38, and the portion between the portion forming the piezoelectric element 32 and the portion forming the common electrode 38 is It becomes common wiring.
The common electrode 38 is an example of the “second electrode”.

  Furthermore, in the longitudinal direction of the piezoelectric element 32, the individual electrode 37 is formed outside the piezoelectric element 32, and the common electrode 38 is formed inside. Further, in the present embodiment, the common electrode 38 extended from the row of the piezoelectric elements 32 on one side and the common electrode 38 extended from the row of the piezoelectric elements 32 on the other side are electrically connected by common wiring. It is connected.

  The first substrate 33 is a relay substrate (wiring substrate) which is disposed between the second substrate 29 and the drive IC 34 and supplies signals of the drive IC 34 to the second substrate 29. The first substrate 33 has a base 330 made of a silicon single crystal substrate, and a wire, an electrode and the like formed on the base 330.

An electrode 67 electrically connected to the individual electrode 37 of the second substrate 29 and a common electrode 38 of the second substrate 29 are electrically connected to the lower surface (the surface on the second substrate 29 side) of the base 330. Electrode 68 is formed. A plurality of electrodes 67 are formed corresponding to the piezoelectric elements 32 along the nozzle row direction.
The electrodes 67 and 68 are examples of the “first electrode”.

  The electrodes 67 and 68 are covered by a protective layer 71. The protective layer 71 is made of, for example, silicon oxide, and has an opening 67 a exposing a part of the electrode 67 and an opening 68 a exposing a part of the electrode 68. The surface 72 opposite to the side covering the electrodes 67 and 68 of the protective layer 71 is subjected to planarization processing and is planarized.

  A bump electrode 40 is formed on the surface 72 of the protective layer 71 (the surface 72 opposite to the electrodes 67 and 68 of the protective layer 71). The bump electrodes 40 are disposed at positions corresponding to the individual electrodes 37 and the common electrode 38 of the second substrate 29. The bump electrode 40 is composed of an elastic internal resin 40 a and a conductive film 41 covering the internal resin 40 a. As internal resin 40a, resin, such as a polyimide resin, can be used, for example. As the conductive film 41, a single metal, an alloy, a metal silicide, a metal nitride, a stacked film in which these are stacked, or the like can be used. The conductive film 41 has a portion 41a covering the internal resin 40a (hereinafter referred to as the conductive film 41a), and a portion 41b covering the surface 72 of the protective layer 71 and the openings 67a and 68a (hereinafter referred to as the conductive film 41b). doing.

  That is, the bump electrode 40 is composed of the internal resin 40a and the conductive film 41a. The conductive film 41 b is a wiring that electrically connects the bump electrode 40 and the electrodes 67 and 68. Since the conductive film 41 b is formed to cover the flat surface 72 of the protective layer 71, the conductive film 41 b has a flat surface 42 in which the shape of the flat surface 72 of the protective layer 71 is reflected.

  The bump electrode 40 has elasticity and is electrically connected to the individual electrode 37 and the common electrode 38 of the second substrate 29 in an elastically deformed state (pressed state). Since the bump electrode 40 has elasticity, the bump electrode 40 and the individual electrode 37, and the bump electrode 40 and the common electrode 38 are each electrically connected better than when the bump electrode 40 does not have elasticity. Be done. Therefore, the electrode 67 of the first substrate 33 is favorably electrically connected to the individual electrode 37 of the second substrate 29 through the bump electrode 40. The electrode 68 of the first substrate 33 is favorably electrically connected to the common electrode 38 of the second substrate 29 via the bump electrode 40.

  In the center of the upper surface (the surface on the drive IC 34 side) of the substrate 330, power (for example, VDD1 (power supply for low voltage circuit), VDD2 (power supply for high voltage circuit), VSS1 (power supply for low voltage circuit) A plurality of (four in this embodiment) power supply wirings 53 for supplying VSS2 (power supply of high voltage circuit)) are formed. Each power supply wiring 53 is extended along the nozzle row direction, that is, the longitudinal direction of the drive IC 34, and an external power supply (not shown) or the like via a wiring board (not shown) such as a flexible cable at the end in the longitudinal direction. And connected. Then, on the power supply wiring 53, the power supply bump electrode 56 of the corresponding drive IC 34 is electrically connected.

  The individual connection terminal 54 is formed at the end of the upper surface of the base material 330 (the area outside the area where the power supply wiring 53 is formed). The individual connection terminal 54 is electrically connected to the individual bump electrode 57 of the drive IC 34, and a signal from the drive IC 34 is input. A plurality of individual connection terminals 54 are formed corresponding to the piezoelectric elements 32 along the nozzle row direction. The individual connection terminal 54 is electrically connected to the electrode 67 formed on the lower surface of the base 330 through the through wiring 45 formed inside the base 330.

  The through wiring 45 is a wiring relaying between the lower surface of the base material 330 and the upper surface of the base material 330, and is filled in the through hole 45a penetrating the base material 330 in the plate thickness direction and inside the through hole 45a. And a conductor portion 45b. The conductor portion 45 b is made of, for example, a metal such as copper (Cu), tungsten (W), nickel (Ni) or the like.

  The drive IC 34 is an IC chip for driving the piezoelectric element 32, and is stacked and arranged on the upper surface (upper surface of the first substrate 33) of the base 330 via an adhesive 59 such as an anisotropic conductive film (ACF). ing. On the surface on the first substrate 33 side of the drive IC 34, the power supply bump electrodes 56 electrically connected to the power supply wiring 53 and the individual bump electrodes 57 electrically connected to the individual connection terminals 54 extend in the nozzle row direction. There are several in parallel.

  Power (voltage) from the power supply wiring 53 is supplied to the drive IC 34 via the power supply bump electrode 56. Then, the drive IC 34 generates signals (drive signal, common signal) for driving the respective piezoelectric elements 32 individually. The drive signal generated by the drive IC 34 is a lower electrode of the piezoelectric element 32 through the individual bump electrode 57, the individual connection terminal 54, the through wiring 45, the electrode 67, the bump electrode 40, and the individual electrode 37. Supplied to the layer. Furthermore, the common signal generated by the drive IC 34 is the upper electrode layer of the piezoelectric element 32 through the wiring (not shown) formed on the base material 330, the electrode 68, the bump electrode 40 and the common electrode 38. Supplied to

  Adhesives 61, 62, 63 are disposed in the non-driving area 36 between the first substrate 33 and the second substrate 29. The adhesives 61, 62, 63 are bonded to the first substrate 33 and the second substrate 29. In other words, the first substrate 33 and the second substrate 29 are bonded by the adhesives 61, 62, 63.

  The adhesives 61, 62, 63 are formed of a photosensitive and thermosetting resin, for example, a resin containing an epoxy resin, an acrylic resin, a phenol resin, a polyimide resin, a silicone resin, a styrene resin or the like as a main component. Although the details will be described later, a photosensitive and thermosetting resin solution (photosensitive adhesive) is applied to the second substrate 29 and patterned by photolithography to form a surface of the second substrate 29 on the first substrate 33 side. The adhesive 61a, 62a, 63a temporarily cured is formed (see FIG. 9). The first substrate 33 is bonded, and the temporarily cured adhesives 61a, 62a, 63a are fully cured in a state of being in contact with the first substrate 33, to form the adhesives 61, 62, 63 (see FIG. 10).

  The adhesives 61 and 62 are arranged in the shape of a strip along the nozzle row direction in the state of being separated from the bump electrode 40 near the bump electrode 40. As described above, the bump electrode 40 is electrically connected to the individual electrode 37 and the common electrode 38 in a state of being elastically deformed. The adhesives 61 and 62 are separated from the bump electrode 40 to such an extent that they do not interfere with the bump electrode 40 even if the bump electrode 40 is elastically deformed.

  FIG. 4 is a schematic plan view seen through the first substrate 33 showing the configuration of the liquid jet head (recording head 3) according to the first embodiment. The adhesive 63 is disposed so as to surround the drive region 35 and the non-drive region 36 (see FIG. 2) at peripheral portions of the first substrate 33 and the second substrate 29, and has a frame shape. Furthermore, as shown in FIGS. 2 to 4, none of the individual electrode 37, the common electrode 38, the electrodes 67 and 68, the bump electrode 40, and the piezoelectric element 32 is included, and the adhesive 63 and the first substrate 33 and the second substrate are included. In a space (second space (described later)) formed by 29, at least one of the first substrate 33 and the second substrate 29 is penetrated, and a through hole 46 communicating with the atmosphere is provided. The individual electrode 37, the common electrode 38, the electrodes 67 and 68, the bump electrode 40, and the piezoelectric element 32 are sealed by the first substrate 33, the second substrate 29, the adhesive 61, and the adhesive 62 (first space ) And the influence of external moisture (humidity) is suppressed. In other words, between the first substrate 33 and the second substrate 29, the individual electrode 37, the common electrode 38, the electrodes 67 and 68, the bump electrode 40, and the piezoelectric element 32 (first space (described later)) adhesive 61 By forming the adhesive 62, the influence of moisture on the individual electrode 37, the common electrode 38, the electrodes 67 and 68, the bump electrode 40, and the piezoelectric element 32 is suppressed, and the individual electrode 37, the common electrode 38, and the electrode due to moisture Deterioration of the bumps 67 and 68, the bump electrode 40, and the piezoelectric element 32 is suppressed.

In the space between the first substrate 33 and the second substrate 29, the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), and the bump electrode 40 (third electrode), A space including the piezoelectric element 32 and configured as a closed space shielded from the air by the first substrate 33, the second substrate 29, the adhesive 61, and the adhesive 62 is an example of the “first space”. That is, the first space is a space surrounded by the adhesives 61 and 62 in plan view from the vertical direction.
In the space between the first substrate 33 and the second substrate 29, the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), Electrodes 67 and 68 other than the space (first space) which includes the piezoelectric element 32 and is configured as a closed space shielded from the atmosphere by the first substrate 33, the second substrate 29, the adhesive 61, and the adhesive 62. None of (the first electrode), the individual electrode 37 and the common electrode 38 (the second electrode), the bump electrode 40 (the third electrode), and the piezoelectric element 32 is included, and at least one of the first substrate 33 and the second substrate 29 A space in communication with the atmosphere through the penetrating through hole 46 is an example of the “second space”.

FIG. 3 is a schematic cross-sectional view showing the configuration of the electronic device according to the first embodiment.
The through hole 46 is formed in at least one of the first substrate 33 or the second substrate 29, and penetrates the base 330 in the thickness direction (in the example of FIG. 3, the first base 33 (base 330 ))). By providing the through holes 46 in the second space other than the first space, the second space is released to the atmosphere. (Refer to FIG. 4) By thus arranging the first space separately from the second space, even if the gas in the second space expands, it has the through holes 46 and communicates with the atmosphere. Therefore, the pressure rise can be reduced, the force against the adhesive force of the adhesives 61, 62, 63 can be reduced, and the positional deviation between the first substrate 33 and the second substrate 29 can be reduced. it can.

  As described above, in the recording head 3, the ink from the ink cartridge 7 is introduced into the pressure generation chamber 30 via the ink introduction path, the reservoir 18, the common liquid chamber 25 and the individual communication path 26. Furthermore, the second substrate 29 is electrically connected to the individual electrode 37 and the common electrode 38 (second electrode), and includes a piezoelectric element 32 that causes the ink in the pressure generation chamber 30 to change in pressure. In this state, the drive signal from the drive IC 34 is supplied to the piezoelectric element 32 of the second substrate 29 through the wiring and electrodes formed on the first substrate 33, thereby driving the piezoelectric element 32 and the piezoelectric element 32 A change in pressure is generated in the pressure generation chamber 30 by the drive of 32. By using this pressure change, in the recording head 3, the ink droplets are ejected from the nozzles 22 through the nozzle communication path 27.

"Production method of recording head"
Next, a method of manufacturing the liquid jet head (recording head 3) according to the present embodiment will be described.
FIG. 5 is a process flow showing a method of manufacturing the recording head 3.

  As shown in FIG. 5, in the method of manufacturing the recording head 3, the step of forming the through hole 46 in the first substrate 33 (step S 1), and the step of forming the bump electrode 40 and the electrodes 67 and 68 in the first substrate 33. (Step S2), forming individual electrodes 37, common electrodes 38, and piezoelectric elements 32 on the second substrate 29 (Step S21), forming adhesives 61, 62, 63 (Step S22), and bonding Curing the agents 61, 62, 63 to bond the first substrate 33 and the second substrate 29 (step S3).

FIG. 6 is a schematic cross-sectional view showing the state after step S1. FIG. 7 is a schematic cross-sectional view showing the state after step S2. FIG. 8 is a schematic cross-sectional view showing the state after step S21. FIG. 9 is a schematic cross-sectional view showing the state after step S22. FIG. 10 is a schematic cross-sectional view showing the state after step S3.
6 to 10 are views corresponding to FIG. 2, and the state of the first substrate 33 is illustrated in FIGS. 6 and 7, and the state of the second substrate 29 is illustrated in FIGS. 8 and 9, The state of the electronic device 14 is illustrated in FIG.

  Furthermore, the vertical direction is reversed in FIGS. 6 and 7 and FIGS. 8 and 9. For example, in FIG. 7, the bump electrode 40 is disposed on the upper side of the base 330, in FIG. 10 the bump electrode 40 is disposed on the lower side of the base 330, and in FIGS. The placement position is upside down. Further, in FIG. 6, FIG. 7 and FIG. 10, illustration of components (the through wiring 45, the power supply wiring 53, the individual connection terminals 54, etc.) of the first substrate 33 unnecessary for the description is omitted.

  In step S 1, the through holes 46 are formed at predetermined positions of the first substrate 33. For example, the substrate 330 is penetrated in the thickness direction using Inductively Coupled Plasma. The processing by inductive coupling plasma can be processed without being restricted by the size and thickness of the holes, as compared with wet etching and the like.

  The inside of the through hole 46 may be covered with a moisture resistant, alkali resistant film. For example, TaO (tantalum oxide) may be deposited by plasma CVD. TaO (tantalum oxide) is superior in water resistance and alkali resistance to silicon oxide.

  In step S2, a photosensitive resin is applied and patterned by a photolithography process or an etching process to form a precursor resin on the surface 72 of the protective layer 71. Subsequently, the precursor resin is melted by heat treatment and the corners are rounded to form the internal resin 40 a on the surface 72 of the protective layer 71. Subsequently, the openings 67a and 68a for exposing the electrodes 67 and 68 are formed in the protective layer 71, and a metal film covering the surface 72 of the protective layer 71 and the openings 67a and 68a is formed by vapor deposition or sputtering, etc. The metal film is patterned by a process to form the conductive film 41 (conductive film 41a and conductive film 41b) covering the internal resin 40a and the openings 67a and 68a. Thereby, as shown in FIG. 7, the bump electrode 40 in which the internal resin 40a is covered by the conductive film 41a is formed. The bump electrode 40 is electrically connected to the electrodes 67 and 68 by the conductive film 41 b covering the openings 67 a and 68 a.

  That is, in step S2, the bump electrode 40 electrically connected to the electrodes 67 and 68 is formed. Furthermore, the protective layer 71 has a portion covered by the conductive film 41 and a flat surface 72 not covered by the conductive film 41. Since the conductive film 41 b is formed to cover the flat surface of the protective layer 71, the conductive film 41 b has a flat surface 42 in which the shape of the flat surface 72 of the protective layer 71 is reflected.

  In step S21, as shown in FIG. 8, the individual electrode 37 and the common electrode 38 are formed on the second substrate 29 by evaporation, sputtering or the like. Furthermore, the piezoelectric element 32 is formed by sputtering or a sol-gel method.

  That is, in the step S21, the individual electrode 37, the common electrode 38 and the piezoelectric element 32 are formed on the second substrate 29. Here, the individual electrode 37, the common electrode 38 and the piezoelectric element 32 are not configured to be protected from moisture by a film such as the protective layer 71.

  In step S22, a liquid resin solution having photosensitivity and thermosetting properties is applied to the second substrate 29 on which the diaphragm 31 and the piezoelectric element 32 are formed. Subsequently, the applied liquid resin solution is pre-baked (prebaked) to form a low flow resin film. Since the liquid resin solution has high fluidity and well covers the unevenness of the second substrate 29, the low flow resin film also well covers the unevenness of the second substrate 29, and the unevenness is formed. Defects such as gaps (hollows) are unlikely to occur in parts. Subsequently, the resin film is patterned by a photolithography process, and after post-baking, low fluidity adhesives 61a, 62a, 63a are formed on the second substrate 29 as shown in FIG.

  That is, in step S22, low-flow adhesive 61a, 62a, 63a is formed by patterning a resin film formed by applying a photosensitive and thermosetting resin solution by photolithography. Do. Furthermore, the low flow adhesive 61a, 62a, 63a is in a state of not completely cured, and has elasticity and adhesiveness.

Further, in step S22, when the adhesives 61, 62, 63 are formed in step S3 described later, the adhesives 61, 62 are arranged so as not to interfere with the bump electrode 40, and the first space can be formed. Adhesives 61a, 62a are disposed as shown.
Furthermore, in the case where the adhesive 63 is formed in step S3 described later, the adhesive 63a is disposed such that the second space can be formed.

Furthermore, since the resin film is patterned by the photolithography method to form the low fluidity adhesives 61a, 62a, 63a, the low fluidity adhesive is compared to, for example, the formation using the dispensing method or the printing method. 61a, 62a, 63a can be formed at predetermined positions with high accuracy. Therefore, the adhesives 61, 62, 63 formed by curing the low flow adhesives 61a, 62a, 63a can also be formed at predetermined positions with high accuracy.
The method of forming the low flow adhesive 61a, 62a, 63a by patterning by photolithography is different from the method of forming the low flow adhesive 61a, 62a, 63a by using the dispensing method or the printing method. It is excellent in miniaturization and can form a fine high definition (high density) pattern.

  In step S3, the first substrate 33 formed through steps S1 and S2 is bonded to the second substrate 29 formed through steps S21 and S22 to form low-flow adhesive 61a, 62a, 63a. Is pressed against the first substrate 33 to cure the low flow adhesive 61 a, 62 a, 63 a, and the adhesive 61 is bonded to both the first substrate 33 and the second substrate 29. , 62, 63 are formed. In other words, the low flow adhesive 61 a, 62 a, 63 a is cured to form the adhesive 61, 62, 63 for bonding the first substrate 33 and the second substrate 29.

  In step S3, as shown in FIG. 10, the adhesives 62 and 63 are bonded to the flat surface 72 of the protective layer 71, and the adhesive 61 is flat on the flat surface 42 of the conductive film 41b and the flat surface 72 of the protective layer 71. It is joined to (see FIG. 7). Then, the protective layer 71 of the first substrate 33 and the second substrate 29 are joined by the adhesives 61, 62, 63.

  Subsequently, anisotropic etching using, for example, KOH is performed on the pressure generation chamber forming substrate 28 to form a through hole 30 a which becomes an empty portion of the pressure generation chamber 30. At the same time, the end of the pressure generation chamber forming substrate 28 is also etched to make the pressure generation chamber forming substrate 28 smaller than the first substrate 33 (base 330). Furthermore, the drive IC 34 is bonded to the surface of the first substrate 33 opposite to the second substrate 29 via the adhesive 59 to manufacture the electronic device 14. Further, the electronic device 14, the flow path unit 15, and the head case 16 are joined to manufacture the recording head 3.

  Step S1 is an example of the “step of forming a through hole in the first substrate”. Step S2 is an example of “the step of forming the third electrode and the first electrode on the first substrate”. Step S21 is an example of “the step of forming the second electrode and the piezoelectric element on the second substrate”. Step S22 is an example of “the step of applying a photosensitive adhesive to the second substrate and patterning by a photolithographic method”. Step S3 is an example of the “step of curing the adhesive”.

As described above, according to the MEMS device, the liquid ejecting head, the liquid ejecting apparatus, and the manufacturing method of the MEMS device according to the present embodiment, the following effects can be obtained.
The electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32 are surrounded by the adhesives 61, 62 and 63, respectively. Deterioration of the electrode due to the penetration of moisture (moisture) from the air release through hole 46 formed in the substrate 33 or the second substrate 29 can be suppressed, and a higher reliability MEMS device can be provided.
In addition, the second space does not include any of the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32, It is configured to include a through hole 46 which penetrates at least one of the substrate and the second substrate and is in communication with the atmosphere. In other words, the first substrate 33 and the second substrate 29 are bonded such that a space opened to the atmosphere is included therebetween.
As described above, by arranging the second space separately from the first space, even if the gas in the second space expands, the through hole 46 is provided and is communicated with the atmosphere. The pressure rise in the two spaces can be reduced, the force against the adhesive force of the adhesives 61, 62, 63 can be reduced, and the positional deviation between the first substrate 33 and the second substrate 29 can be reduced. The second space is a space not including any of the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32. Therefore, even if the communication with the atmosphere is performed, the reliability may not be deteriorated, and a higher reliability MEMS device can be provided.

  In addition, as the liquid jet head (recording head 3), the second substrate 29 includes the piezoelectric element 32 electrically connected to the individual electrode 37 and the common electrode 38 (second electrode). Then, the piezoelectric element 32 provided on the second substrate 29 includes the electrodes 67 and 68 of the first substrate 33 via the individual electrode 37 and the common electrode 38 (second electrode) and the bump electrode 40 (third electrode). It is stably and electrically connected to the (first electrode). Therefore, a drive signal can be stably supplied to the piezoelectric element 32 from the first substrate 33 side, and the liquid jet head in which the piezoelectric element 32 operates stably can be provided. Thus, the liquid jet head operates stably and has high reliability. Therefore, the liquid ejecting apparatus (printer 1) including the liquid ejecting head (recording head 3) also operates stably and has higher reliability.

  In the method of manufacturing the recording head 3 according to the present embodiment, in the space between the first substrate 33 and the second substrate 29, the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode) And the bump electrode 40 (third electrode) and the piezoelectric element 32 are disposed separately from the second space, thereby providing the through holes 46 even if the gas in the second space is expanded. Since the pressure sensor is in communication with the atmosphere, the pressure rise can be reduced, and the force against the adhesive force of the adhesive 61, 62, 63 is reduced, and the first substrate 33 and the second substrate 29 Since the positional deviation can be reduced, the failure of the recording head 3 can be suppressed and the reliability of the recording head 3 can be further enhanced.

  Furthermore, in the method of manufacturing the recording head 3 according to the present embodiment, the first space and the second space are formed in the space between the first substrate 33 and the second substrate 29. The deterioration of the electrode due to the penetration of moisture (moisture) can be suppressed, the failure of the recording head 3 can be suppressed, and the reliability of the recording head 3 can be further enhanced.

Second Embodiment
FIG. 11 is a diagram corresponding to FIG. 2 and is a schematic cross-sectional view showing the configuration of the liquid jet head (recording head 3A) according to the second embodiment.
In the recording head 3 according to the first embodiment, the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32 in the first space In the present embodiment (embodiment 2), the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode) are used in the present embodiment (embodiment 2). The example which arrange | positions "wiring" which connects bump electrode 40 (3rd electrode), piezoelectric element 32 grade | etc., In 2nd space is demonstrated.
In the recording head 3A according to the present embodiment, the protective layer 71A is formed on the “wiring” disposed in the second space communicating with the air without being surrounded by the adhesives 61 and 62 in the second substrate 29A. There is. This point is the difference between the recording head 3A according to the present embodiment and the recording head 3 according to the first embodiment, and the other configurations are the same in the present embodiment and the first embodiment.
Hereinafter, with reference to FIG. 11, an outline of the recording head 3A according to the present embodiment will be described focusing on differences from the first embodiment. The same components as in the first embodiment will be assigned the same reference numerals and redundant explanations will be omitted.

  As shown in FIG. 11, the recording head 3 </ b> A includes a flow path unit 15, an electronic device 14 </ b> A, and a head case 16.

  The electronic device 14A is a thin plate-like MEMS device that functions as an actuator that generates a pressure change in the ink in each pressure generation chamber 30. That is, the electronic device 14A causes a pressure change in the ink in each pressure generation chamber 30, and ejects the ink from the nozzles 22 communicated with each pressure generation chamber 30. The electronic device 14A has a configuration in which a second substrate 29A, adhesives 61, 62, 63, and a first substrate 33 are sequentially stacked and unitized.

The first substrate 33 is stacked on the second substrate 29A, and a base 330 on which a drive circuit 39 for driving the piezoelectric element 32 (not shown in FIG. 11) is formed. Electrode (electrode 67, electrode 68, bump electrode 40), and the like.
The second substrate 29A is stacked on the first substrate 33, and includes a pressure generation chamber formation substrate 28, a diaphragm 31, a piezoelectric element 32, an individual electrode 37, and a common electrode 38.
Further, as shown in FIG. 11, in the second substrate 29A, the wiring 50 is disposed in a second space communicating with the atmosphere. The wire 50 is a wire electrically connected to at least one of the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32. It is.

  The adhesives 61, 62, 63 are bonded to the first substrate 33 and the second substrate 29A. In other words, the first substrate 33 and the second substrate 29A are bonded by the adhesives 61, 62, 63.

The protective layer 71A includes individual wiring (the wiring between the portion forming the piezoelectric element 32 and the portion forming the individual electrode 37 (see FIG. 2)) disposed in the second space and the common wiring (the piezoelectric element 32). For the wiring (see FIG. 2)) between the portion to be formed and the portion forming the common electrode 38, the wiring 50 and the like, they are formed in the stacking direction. In other words, the individual wires, the common wires, the wires 50 and the like in the second space are covered by the protective layer 71A.
The individual wiring and the common wiring disposed in the second space include the wiring 50 and correspond to the “wiring” in the present invention.

  A plurality of adhesion regions by the adhesives 61, 62, 63 are configured to adhere the first substrate 33 and the second substrate 29A with the protective layer 71A interposed therebetween. In other words, the protective layer 71A is located between the first substrate 33 and the adhesive 61, 62, 63 formed on the second substrate 29A, and is bonded.

  Temporarily, the bonding surface 72A to which the adhesives 61, 62, 63 are bonded is a convexo-concave portion due to the presence or absence of the protective layer 71A, and a portion where the first substrate 33 and the second substrate 29A are bonded with the protective layer 71A interposed therebetween; The adhesive 61, 62, 63 has a portion for bonding the first substrate 33 and the second substrate 29A without sandwiching the protective layer 71A, and the bonding between the first substrate 33 and the second substrate 29A is inclined. There is a possibility that a gap (hollow) may be formed between the layers of and the protective layer 71A. As a result, water (moisture) infiltrates through the gap, and the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), and the bump electrode 40 (in the first space) are formed. The third electrode may be deteriorated by the moisture, and the reliability of the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), and the bump electrode 40 (third electrode) may be deteriorated. is there.

Furthermore, when the bonding reliability between the adhesives 61, 62, 63 and the bonding surface of the first substrate 33 is low, defects such as peeling and cracks occur in the portion where the bonding agent 63 and the bonding surface of the first substrate 33 are bonded. When the above-described anisotropic etching with KOH is performed, an etchant permeates from the defect to cause the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), and the bump electrode 40 (second electrode). There may occur a problem that the three electrodes) deteriorate.
Furthermore, when the bonding reliability between the adhesives 61, 62, 63 and the bonding surface of the first substrate 33 is low, the mechanical bonding causes the bonding surfaces of the adhesives 61, 62, 63 and the first substrate 33 to be bonded. It is likely that defects such as peeling and cracks will easily occur in the portion where the recording head 3A is deteriorated, and the reliability of the recording head 3A may be lowered.

  For example, silicon oxide (protective layer 71A) covering the individual electrode 37, the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32 is formed by plasma CVD using TEOS (tetraethoxysilane). Do. Silicon oxide formed by plasma CVD using TEOS has excellent step coverage, and well covers irregularities such as the individual electrode 37, the common electrode 38 (second electrode), and the bump electrode 40 (third electrode). Can.

The protective layer 71A may be a multilayer film including silicon oxide and silicon nitride. For example, after depositing silicon oxide by plasma CVD using TEOS, silicon nitride thicker than silicon oxide may be deposited by plasma CVD, and the silicon nitride may be planarized by CMP. For example, silicon nitride may be formed by plasma CVD over silicon oxide planarized by CMP.
Silicon nitride is superior in water resistance to silicon oxide. The water resistance of the protective layer 71A can be enhanced by forming the protective layer 71A with a multilayer film containing silicon oxide and silicon nitride.

As described above, according to the MEMS device and the liquid jet head according to the present embodiment, the following effects can be obtained.
Moisture (moisture) from the through holes 46 formed in the first substrate 33 or the second substrate 29A by covering the individual wires, the common wires, the wires 50, etc. included in the second space communicating with the atmosphere with the protective layer 71A. In this case, the degradation due to the intrusion of H can be suppressed, and a higher reliability MEMS device can be provided.
Further, in the liquid jet head (recording head 3A), as compared with the case where the bonding between the first substrate 33 and the second substrate 29A is inclined, between the adhesive 61, 62, 63 and the bonding surface of the protective layer 71A. It is difficult to form a gap (hollow) in the case and it is possible to suppress the entry of moisture (moisture).
Further, in the recording head 3A, since the bonding reliability between the adhesives 61, 62, 63 and the bonding surface of the first substrate 33 is higher, the bonding surfaces of the adhesives 61, 62, 63 and the first substrate 33 are As compared to the case where the bonding reliability with the adhesive is low, defects such as peeling and cracking are less likely to occur at the portions where the adhesives 61, 62, 63 and the bonding surface of the first substrate 33 are bonded. Thus, the reliability of the recording head 3A can be further enhanced.

(Embodiment 3)
FIG. 12 is a diagram corresponding to FIG. 2 and is a schematic cross-sectional view showing the configuration of the liquid jet head (recording head 3B) according to the third embodiment. In addition, the same code | symbol is attached | subjected to the member similar to embodiment mentioned above, and the overlapping description is abbreviate | omitted.

As shown in FIG. 12, the recording head 3 </ b> B includes a flow path unit 15, an electronic device 14 </ b> B, and a head case 16.
The electronic device 14B has a configuration in which the second substrate 29, the adhesives 61, 62, 63, the first substrate 33, and the drive IC 34 are sequentially stacked and unitized.

  The first substrate 33 has a base material 330 made of a silicon single crystal substrate, a bump electrode 40 provided on the base material 330, and a protective layer 71 covering a main part of the base material 330 on the bump electrode 40 side.

  The bump electrode 40 is provided directly on the surface of the base 330 on the second substrate 29 side. The bump electrode 40 includes an elastic internal resin 40 a and a conductive film 41 covering the internal resin 40 a. Such bump electrodes 40 are provided at positions corresponding to the individual electrodes 37 and the common electrode 38 of the second substrate 29. The conductive film 41 has a portion covering the internal resin 40 a (hereinafter, conductive film 41 a) and a portion formed on the surface of the base 330 (hereinafter, conductive film 41 b). The conductive film 41b constituting the bump electrode 40 is extended to a position covering the opening of the through hole 45a, and the conductive film 41b and the conductor portion 45b filled in the through hole 45a are directly connected. That is, in the present embodiment, the conductive film 41 of the bump electrode 40 doubles as the electrodes 67 and 68 in the first and second embodiments described above. That is, the conductive film 41 is an example of the “first electrode”. Of course, the electrodes 67 and 68 similar to those of Embodiments 1 and 2 described above may be provided on the base 330 separately from the conductive film 41 of the bump electrode 40.

  The protective layer 71 is provided on the surface of the base 330 on the second substrate 29 side, and is provided to cover a part of the conductive film 41 b of the bump electrode 40 provided on the second substrate 29. . Further, in the protective layer 71, at the position where the bump electrode 40 is provided, a connection hole 73 penetrating the protective layer 71 in the vertical direction is provided. In the connection hole 73 of the protective layer 71, the internal resin 40a of the bump electrode 40 and the conductive film 41a provided on the surface thereof are inserted. Further, the tip end of the bump electrode 40 inserted into the connection hole 73 is provided so as to protrude toward the second substrate 29 side than the surface 72 of the protective layer 71, and the tip end of the protruding bump electrode 40 is the second substrate The 29 individual electrodes 37 and the common electrode 38 are connected to each other. That is, the protective layer 71 has a thickness thinner than the height of the bump electrode 40 protruding to the second substrate 29 side than the base material 330, and the conductive film of the bump electrode 40 on the surface of the base material 330 on the second substrate 29 side It is provided continuously over the area other than 41a.

  In addition, the first substrate 33 and the second substrate 29 are bonded by the adhesives 61, 62, 63. In the present embodiment, the protective layer 71 of the first substrate 33 and the second substrate 29 are bonded by the adhesives 61, 62, 63.

As described above, according to the MEMS device and the liquid jet head according to the present embodiment, the following effects can be obtained.
The conductive film 41 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32 are surrounded by the adhesives 61, 62, 63, and the first substrate The deterioration of the electrode due to the penetration of moisture (moisture) from the air release through hole 46 formed in the substrate 33 or the second substrate 29 can be suppressed, and a MEMS device with higher reliability can be provided.
Further, the second space does not include any of the conductive film 41 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32, and the first substrate 33, at least one of the second substrate 29 is configured to include a through hole 46 communicating with the atmosphere. In other words, the first substrate 33 and the second substrate 29 are bonded such that a space opened to the atmosphere is included therebetween.
As described above, by arranging the second space separately from the first space, even if the gas in the second space expands, the through hole 46 is provided and is communicated with the atmosphere. The pressure rise in the two spaces can be reduced, the force against the adhesive force of the adhesives 61, 62, 63 can be reduced, and the positional deviation between the first substrate 33 and the second substrate 29 can be reduced. The second space is a space not including any of the electrodes 67 and 68 (first electrode), the individual electrode 37 and the common electrode 38 (second electrode), the bump electrode 40 (third electrode), and the piezoelectric element 32. Therefore, even if the communication with the atmosphere is performed, the reliability may not be deteriorated, and a higher reliability MEMS device can be provided.

  Further, as a liquid jet head (recording head 3B), the second substrate 29 is provided with a piezoelectric element 32 electrically connected to the individual electrode 37 and the common electrode 38 (second electrode). The piezoelectric element 32 provided on the second substrate 29 is a first electrode (first electrode) of the first substrate 33 via the individual electrode 37, the common electrode 38 (second electrode), and the bump electrode 40 (third electrode). For example, the conductive film 41) is stably and electrically connected. Therefore, a drive signal can be stably supplied to the piezoelectric element 32 from the first substrate 33 side, and the liquid jet head in which the piezoelectric element 32 operates stably can be provided. Thus, the liquid jet head (recording head 3B) operates stably and has high reliability. Therefore, the liquid ejecting apparatus (printer 1) including the liquid ejecting head (recording head 3B) also operates stably and has higher reliability.

In the present embodiment, the protective layer 71 is provided continuously on the surface of the base material 330 on the second substrate 29 side over the area other than the conductive film 41 a of the bump electrode 40, but the invention is particularly limited thereto. Alternatively, the protective layer 71 may not be provided in a region other than the conductive film 41 b on the base material 330 of the bump electrode 40.
Moreover, in the present embodiment, the protective layer 71 is provided on both the conductive film 41 b of the bump electrode 40 connected to the individual electrode 37 and the conductive film 41 b of the bump electrode 40 connected to the common electrode 38. However, the invention is not particularly limited thereto, and the protective layer 71 may be either the conductive film 41 b of the bump electrode 40 connected to the individual electrode 37 or the conductive film 41 b of the bump electrode 40 connected to the common electrode 38. It may be provided to cover the As described above, the configuration in which the protective layer 71 is provided only on a part of the conductive films 41 b of the plurality of bump electrodes 40 can be realized by the configuration in which the bump electrodes 40 are directly formed on the base 330 as in this embodiment. It is. That is, in the present embodiment, since the bump electrode 40 is directly formed on the base material 330, even if the protective layer 71 is partially provided on the conductive film 41b, a plurality of bump electrodes are formed depending on the presence or absence of the protective layer 71. This is because variations in height do not occur in 40, and the plurality of bump electrodes 40 can be connected to the individual electrodes 37 and the common electrode 38 at the same height.

  Furthermore, the present invention is intended for a wide range of heads in general, for example, recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, and colors used in manufacturing color filters such as liquid crystal displays. The present invention can also be applied to electrode material jet heads used for forming electrodes of materials jet heads, organic EL displays, FEDs (field emission displays), etc., and bioorganic jet heads used for biochip manufacture, etc. The technical scope of

In addition, the present invention is widely intended for MEMS devices, and can be applied to MEMS devices other than the recording heads 3 and 3A described above. For example, a SAW device (surface acoustic wave device), an ultrasonic device, a motor, a pressure sensor, a pyroelectric element, and a ferroelectric element are an example of a MEMS device, to which the present invention can be applied. It is a technical range.
In addition, a complete body using these MEMS devices, for example, the liquid ejecting apparatus using the recording head 3 or 3A described above, a SAW oscillator using the SAW device, an ultrasonic sensor using the ultrasonic device, the motor The present invention can also be applied to a robot used as a drive source, an IR sensor using the above-mentioned pyroelectric element, a ferroelectric memory using a ferroelectric element, and the like, and is within the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... printer, 2 ... recording medium, 3 ... recording head, 4 ... carriage, 5 ... carriage movement mechanism, 6 ... conveyance mechanism, 7 ... ink cartridge, 8 ... timing belt, 9 ... pulse motor, 10 ... guide rod, 11 ... Cap 12 12 wiping unit 14 electronic device 15 flow unit 16 head case 18 reservoir 21 nozzle plate 22 nozzle 24 communication substrate 25 common liquid chamber 25 a 25 a First liquid chamber, 25b: second liquid chamber, 26: individual communication passage, 27: nozzle communication passage, 28: pressure generating chamber forming substrate, 29: second substrate, 30: pressure generating chamber, 30a: through hole, 31 ... Vibrating plate, 32 ... Piezoelectric element, 33 ... First substrate, 35 ... Drive area, 36 ... Non-drive area, 37 ... Individual electrode, 38 ... Common electrode, 39 ... Drive circuit, 40 ... Bump electricity , 40a: internal resin, 41, 41a, 41b: conductive film, 42: surface, 45: through wiring, 45a: through hole, 45b: conductor portion, 50: wiring, 53: power supply wiring, 54: individual connection terminal, 56 ... Power supply bump electrode, 57 ... Individual bump electrode, 61, 62, 63 ... Adhesive, 67, 68 ... Electrode, 67a, 68a ... Opening, 71 ... Protective layer, 71A ... Protective layer, 72 ... Surface (flat joint surface ), 72A ... surface (flat joint surface), 73 ... connection hole, 330 ... base material

Claims (6)

A first substrate having a first electrode;
A second substrate having a second electrode, and wherein the first electrode and the second electrode are stacked and disposed between the second electrode and the first substrate;
A third electrode disposed between the first substrate and the second substrate and electrically connecting the first electrode and the second electrode;
A piezoelectric element disposed between the first substrate and the second substrate;
An adhesive for bonding the first substrate and the second substrate;
In the space between the first substrate and the second substrate, the first electrode, the second electrode, the third electrode, and includes the piezoelectric element, the first substrate, the second substrate And a first space configured as a closed space shielded from the atmosphere by the adhesive.
In the space between the first substrate and the second substrate, none of the first electrode, the second electrode, the third electrode, and the piezoelectric element is included, and the first substrate and the 2. A MEMS device comprising: a second space communicating with the atmosphere by a through hole penetrating at least one of the two substrates. A wiring electrically connected to at least one of the first electrode, the second electrode, the third electrode, and the piezoelectric element;
The MEMS device according to claim 1, wherein the wiring included in the second space is shielded from the atmosphere by a protective layer covering the wiring.   The MEMS device according to claim 2, wherein the plurality of adhesion regions by the adhesive bond the first substrate and the second substrate with the protective layer interposed therebetween.   A liquid jet head comprising the MEMS device according to any one of claims 1 to 3.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 4. A first substrate having a first electrode;
A second substrate having a second electrode, and wherein the first electrode and the second electrode are stacked and disposed between the second electrode and the first substrate;
A third electrode disposed between the first substrate and the second substrate and electrically connecting the first electrode and the second electrode;
A piezoelectric element disposed between the first substrate and the second substrate;
A manufacturing method of a MEMS device, comprising: an adhesive for bonding the first substrate and the second substrate,
Wherein the space between the first substrate and the second substrate, the first electrode, the second electrode, the third electrode, and the first space includes the piezoelectric element, the first substrate, The second substrate is configured as a closed space shielded from the atmosphere by the adhesive,
In a space between the first substrate and the second substrate, a second space not including any of the first electrode, the second electrode, the third electrode, and the piezoelectric element is the first space. Forming a through hole penetrating at least one of the substrate and the second substrate and communicating with the atmosphere;
Heat curing the adhesive, and manufacturing the MEMS device.

Images