Patent Publication Number: US-9902150-B2

Title: Liquid ejecting head, and manufacturing method of liquid ejecting head

Description:
The entire disclosure of Japanese Patent Application No: 2015-205299, filed Oct. 19, 2015 is expressly incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting head that is provided with a substrate on which wiring that penetrates through a plate thickness direction, is formed, and a manufacturing method of a liquid ejecting head. 
     2. Related Art 
     A liquid ejecting apparatus is an apparatus that is provided with a liquid ejecting head, and that ejects various liquids from the liquid ejecting head. Image recording apparatuses such as ink jet printers and ink jet projectors are examples of such liquid ejecting apparatuses, but in recent years, liquid ejecting apparatuses have also been applied to various manufacturing apparatuses to make use of the feature of being able to accurately land a very small quantity of liquid in a predetermined position. For example, liquid ejecting apparatuses have been applied to display manufacturing apparatuses that manufacture color filters such as liquid crystal displays, electrode formation apparatuses that form electrodes such as organic Electro Luminescence (EL) displays and Field Emitting Displays (FEDs), and chip manufacturing apparatuses that manufacture biochips (biochemical elements). Further, liquid form ink is ejected in recording heads for image recording apparatuses, and solutions of each color material of Red (R), Green (G), and blue (B) are ejected in color material ejecting heads for display manufacturing apparatuses. In addition, liquid form electrode materials are ejected in electrode material ejecting heads for electrode formation apparatuses, and solutions of living organic material are ejected in living organic material ejecting heads for chip manufacturing apparatuses. 
     In the abovementioned liquid ejecting heads, a pressure chamber formation substrate on which a pressure chamber that is in communication with a nozzle, is formed, a piezoelectric element (a kind of actuator) that brings about a pressure fluctuation in liquid inside the pressure chamber, a sealing plate (also referred to as an interposer board) in which a gap is opened and disposed to correspond to the corresponding piezoelectric element, and the like are laminated. Further, the above-mentioned piezoelectric element is driven by a driving signal that is supplied from a driving IC (also referred to as a driver IC). This kind of driving IC is installed in a Tape Carrier Package (TCP) which is connected to an upper surface (a surface that is on an opposite side to a piezoelectric element) of a sealing plate, or is directly installed on the upper surface of the sealing plate, and supplies a driving signal to the piezoelectric element through wiring that is formed on the sealing plate. The wiring that relays between the driving IC and the piezoelectric element is configured from outer surface wiring that is formed on the upper surface and the lower surface of the sealing plate, penetration wiring that is formed inside a penetration hole and penetrates through the sealing plate, and the like (for example, JP-A-2012-126028). 
     Incidentally, for example, a method that grows a conductor (a metal) inside a penetration hole, in which an adhesive layer (a seed layer), which improves adhesive properties with a conductor, is formed as a film, using an electrolytic plating technique by forming the adhesive layer as a film inside the penetration hole using a sputtering technique or the like, is an example of a method that forms penetration wiring inside the penetration hole of the above-mentioned sealing plate. However, in accordance with the miniaturization of liquid ejecting heads, when the internal diameter of the penetration hole is reduced, and the aspect ratio (a ratio of the length L of the penetration hole (or the substrate thickness) with respect to the opening diameter D of the penetration hole, that is, L/D) of the penetration hole is increased, it is difficult to form the adhesive layer in an inner portion of the penetration hole. Therefore, a sputtering technique that can form an adhesive layer having a favorable coverage (covering) ratio up to the inner portion, in even a penetration hole having a comparatively large aspect ratio, was developed (refer to JP-A-2012-111996). 
     As the miniaturization of liquid ejecting heads continues, and aspect ratios of penetration holes are further increased, there is a concern that it will not be possible to form a sufficient adhesive layer even using the method that is disclosed in JP-A-2012-111996. That is, there is a concern that the coverage (covering) ratio of the adhesive layer in the inner portion inside the penetration hole will deteriorate. As a result of this, when the adhesive properties of a conductor, which is formed inside the penetration hole, and the inner wall of the penetration hole deteriorate, and heat is applied due to a subsequent manufacturing process, a specification environment of a product, or the like, there is a concern that the conductor inside the penetration hole will stick out (protrude), or will slip out, to an outer side from the penetration hole due to a difference in the thermal expansion coefficients of the sealing plate and the conductor. In addition, even supposing it is possible to form an adhesive layer inside the penetration hole, when the difference between the thermal expansions of the sealing plate and the conductor is large, there is a concern that sticking out, or slipping out of the conductor will occur. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a liquid ejecting head, and a manufacturing method of a liquid ejecting head that can suppress a circumstance in which penetration wiring sticks out from the penetration hole even when heat, an external force, or the like is applied thereto. 
     According to an aspect of the invention, there is provided a liquid ejecting head including a first substrate in which a piezoelectric element is provided, and a second substrate on which the first substrate is connected to a first surface, the second substrate is provided with a penetration hole, which penetrates through the second substrate in a plate thickness direction, and penetration wiring, which is formed from a conductor that is formed in an inner portion of the penetration hole, the penetration wiring is formed from a first end portion, which is provided on a first surface side, a second end portion, which is provided on a second surface side, which is a surface that is on an opposite side to the first surface, and connection wiring, which connects the first end portion and the second end portion, and a cross-sectional area of the connection wiring in a planar direction of the first surface is smaller than cross-sectional areas of the first end portion and the second end portion in the planar direction. 
     In this case, since the cross-sectional area of the connection wiring is smaller than the cross-sectional areas of the of the first end portion and the second end portion, it is possible to suppress a circumstance in which the penetration wiring sticks out to an outer side of the penetration hole even when heat, an external force, or the like, is applied to the second substrate. 
     In the liquid ejecting head, it is preferable that the cross-sectional area of the first end portion or the second end portion in the planar direction of the first surface increases from the connection wiring toward the first surface or the second surface. 
     In this case, since it is possible to create a portion of the penetration hole using a wet etching technique, the manufacture of the second substrate is facilitated. In addition, it is possible to reduce an angle inside the penetration hole at which it is easy for an electric field and stress to concentrate. 
     In the liquid ejecting head, it is preferable that an electrode terminal, which performs electrical connection with the first substrate, is formed on the first surface of the second substrate, and that the electrode terminal is formed on an outer surface of a resin that is formed on the first surface. 
     In this case, since a resin is elastically deformed when the electrode terminal is connected to a terminal of a first substrate side as a result of applying pressure to the first substrate side, it is possible to reliably connect the electrode terminal due to a small increase in weight. In addition, even if heat is applied during the formation of the resin, it is possible to suppress a circumstance in which the penetration wiring sticks out to the outer side from the penetration hole due to a difference in the thermal expansion coefficients (the linear expansion coefficients) of the second substrate and the penetration wiring. 
     In the liquid ejecting head, it is preferable that the penetration wiring is disposed extending in a direction that is perpendicular to the first surface. 
     In this case, it is easy to form the penetration wiring, and therefore, the manufacture of the second substrate is further facilitated. 
     According to another aspect of the invention, there is provided a manufacturing method of a liquid ejecting head that includes a first substrate in which a piezoelectric element is provided, and a second substrate on which the first substrate is connected to a first surface, the method including forming a first recessed portion on the first surface of the second substrate, forming a second recessed portion on the second surface, which is on an opposite side to the first surface, of the second substrate, forming a penetration channel, a cross-sectional area in the planar direction of the first surface of which is smaller than those of the first recessed portion and the second recessed portion, between the first recessed portion and the second recessed portion, and causing the penetration channel to penetrate through the second substrate, and forming a conductor in an inner portion of each of the first recessed portion, the second recessed portion and the penetration channel using an electrolytic plating technique. 
     In this case, it is possible to easily form a conductor (that is, penetration wiring) in which the cross-sectional area on a surface that is parallel to the first surface, increases from midway in the plate thickness direction of the second substrate toward the first surface and the second surface that is on the opposite side to the first surface. In addition, since the conductor is formed using an electrolytic plating technique, it is possible to reliably form the conductor inside the penetration channel in even a case in which the aspect ratio of the penetration channel is high. 
     In the manufacturing method of a liquid ejecting head, it is preferable that at least one of the forming of the first recessed portion and the forming of the second recessed portion includes removing the second substrate using a dry etching technique. 
     In this case, it is possible to form the first recessed portion or the second recessed portion with high accuracy. 
     In the manufacturing method of a liquid ejecting head, it is preferable that at least one of the forming of the first recessed portion and the forming of the second recessed portion includes removing the second substrate using a wet etching technique. 
     In this case, it is possible to form the first recessed portion or the second recessed portion in a short period of time. In addition, if a crystalline substrate on which etching proceeds in a direction that is inclined with respect to the first surface, is used as the second substrate, it is possible to configure an inner wall of the first recessed portion or the second recessed portion as an inclined surface. As a result of this, it is possible to reduce an angle at which it is easy for an electric field and stress to concentrate. 
     In the manufacturing method of a liquid ejecting head, it is preferable that the forming of the conductor includes a laser machining technique. 
     In this case, it is possible to form a penetration channel having a high aspect ratio. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view that describes a configuration of a printer. 
         FIG. 2  is a cross-sectional view that describes a configuration of a recording head. 
         FIG. 3  is a cross-sectional view in which main portions of a sealing plate are enlarged. 
         FIG. 4  is a cross-sectional view that describes a configuration of penetration wiring. 
         FIG. 5  is a cross-sectional view that describes a manufacturing process of penetration wiring. 
         FIG. 6  is a cross-sectional view that describes the manufacturing process of penetration wiring. 
         FIG. 7  is a cross-sectional view that describes the manufacturing process of penetration wiring. 
         FIG. 8  is a cross-sectional view that describes the manufacturing process of penetration wiring. 
         FIG. 9  is a cross-sectional view in which main parts of a sealing plate in a second embodiment are enlarged. 
         FIG. 10  is a cross-sectional view that describes a manufacturing process of penetration wiring in the second embodiment. 
         FIG. 11  is a cross-sectional view that describes the manufacturing process of penetration wiring in the second embodiment. 
         FIG. 12  is a cross-sectional view that describes the manufacturing process of penetration wiring in the second embodiment. 
         FIG. 13  is a cross-sectional view that describes the manufacturing process of penetration wiring in the second embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, aspects for implementing the invention will be described with reference to the appended drawings. Additionally, since the embodiments that are mentioned below are preferred specific examples of the invention, various limitations have been applied thereto, but the scope of the invention is not limited to these aspects unless a feature that specifically limits the invention is disclosed in the following description. In addition, in the following description, examples of an ink jet type recording head (hereinafter, referred to as a recording head), which is a type of a liquid ejecting head, and an ink jet type printer (hereinafter, referred to as a printer), which is a type of liquid ejecting apparatus, in which such an ink jet type recording head is mounted, are illustrated as examples. 
     A configuration of a printer  1  will be described with reference to  FIG. 1 . The printer  1  is an apparatus that performs the recording of images or the like by ejecting an ink (a type of liquid) onto an outer surface of a recording medium  2  (a type of landing target) such as recording paper. The printer  1  is provided with a recording head  3 , a carriage  4  to which the recording head  3  is attached, a carriage movement mechanism  5  that moves the carriage  4  in a main scanning direction, a transport mechanism  6  that transfers the recording medium  2  in a sub-scanning direction, and the like. In this instance, the abovementioned ink is retained in ink cartridges  7  as liquid supply sources. The ink cartridges  7  are installed in the recording head  3  in an attachable and detachable manner. Additionally, it is possible to adopt a configuration in which the ink cartridges are disposed on a main body side of the printer, and ink is supplied to the recording head from the ink cartridges through an ink supply tube. 
     The carriage movement mechanism  5  is provided with a timing belt  8 . Further, the timing belt  8  is driven by a pulse motor  9  such as a DC motor. Accordingly, when the pulse motor  9  is activated, the carriage  4  reciprocates in the main scanning direction (a width direction of the recording medium  2 ) guided on a guide rod  10 , which is provided in a hanging manner in the printer  1 . The position of the carriage  4  in the main scanning direction is detected by a linear encoder (not illustrated in the drawings), which is a type of positional information detection unit. The linear encoder sends a detection signal thereof, that is, an encoder pulse (a type of positional information) to a control section of the printer  1 . 
     Next, the recording head  3  will be described.  FIG. 2  is a cross-sectional view that describes a configuration of the recording head  3 .  FIG. 3  is a cross-sectional view in which the main parts of a sealing plate  33  are enlarged.  FIG. 4  is a cross-sectional view that describes a configuration of penetration wiring  45 . As shown in  FIG. 2 , the recording head  3  in the present embodiment is attached to a head case  16  in a state in which a piezoelectric device  14  and a flow channel unit  15  are laminated. Additionally, for the convenience of description, the lamination direction of each member will be described as the up-down direction. 
     The head case  16  is a synthetic resin box-shaped member, and liquid introduction paths  18  that supply ink to common liquid chambers  25 , which will be described later, are formed in an inner section thereof. The liquid introduction paths  18  are spaces in which ink that is common to pressure chambers  30  that are arranged in parallel in a plurality, is stored in addition to the common liquid chambers  25 , which will be described later. In the present embodiment, two liquid introduction paths  18  are formed to correspond to a row of the pressure chambers  30 , which are arranged in parallel in two rows. In addition, an accommodation space  17 , which is recessed in a rectangular parallelepiped shape from a lower surface side of the head case  16  to midway in a height direction of the head case  16 , is formed between the two liquid introduction paths  18 . The piezoelectric device  14  (a pressure chamber formation substrate  29 , a sealing plate  33 , and the like), which is laminated on a communication substrate  24 , is accommodated inside the accommodation space  17 . 
     The flow channel unit  15 , which is joined to the lower surface of the head case  16 , includes the communication substrate  24 , and a nozzle plate  21 . The communication substrate  24  is a plate material made from silicon, and in the present embodiment, is prepared from a monocrystalline silicon substrate in which the crystal plane orientation of the outer surfaces (the upper surface and the lower surface) is set as ( 110 ). As shown in  FIG. 2 , the common liquid chambers  25 , which are in communication with the liquid introduction paths  18 , and in which ink that is common to each pressure chamber  30  is stored, and individual communication channels  26  that individually supply ink from the liquid introduction paths  18  to each pressure chamber  30  via the common liquid chambers  25 , are formed in the communication substrate  24  using etching (a wet etching technique or a dry etching technique). The common liquid chambers  25  are longitudinal space sections along a nozzle row direction, and two rows of the common liquid chambers  25  are formed to correspond to a row of pressure chambers  30 , which are arranged in parallel in two rows. A plurality of the individual communication channels  26  are opened in positions of the common liquid chambers  25  that correspond to the pressure chambers  30 . That is, a plurality of the individual communication channels  26  are formed along a parallel arrangement direction of the pressure chambers  30 . The individual communication channels  26  are in communication with an end section of one side in the longitudinal direction of a corresponding pressure chamber  30  in a state in which the communication substrate  24  and the pressure chamber formation substrate  29  are joined. 
     In addition, nozzle communication channels  27 , which penetrate through the plate thickness direction of the communication substrate  24 , are formed in positions that correspond to each nozzle  22  of the communication substrate  24 . That is, the nozzle communication channels  27  are formed in a plurality along a corresponding nozzle row direction, which corresponds to a nozzle row. The pressure chambers  30  and the nozzles  22  are in communication with one another due to these nozzle communication channels  27 . The nozzle communication channels  27  of the present embodiment are in communication with an end section of the other side in the longitudinal direction of a corresponding pressure chamber  30  (a side that is opposite to the individual communication channel  26 ) in a state in which the communication substrate  24  and the pressure chamber formation substrate  29  are joined. 
     The nozzle plate  21  is a substrate made from silicon (for example, a monocrystalline silicon substrate), which is joined to the lower surface of the communication substrate  24  (a surface on a side that is opposite to the pressure chamber formation substrate  29 ). In the present embodiment, openings that are on a lower surface side of the spaces that correspond to the common liquid chambers  25  are sealed by the nozzle plate  21 . In addition, a plurality of nozzles  22  are provided in an open manner in the nozzle plate  21  in a linear manner (row form). In the present embodiment, two nozzle rows are formed to correspond to a row of pressure chambers  30 , which are formed in two rows. A plurality of nozzles  22  that are arranged in parallel (a nozzle row) are provided at regular intervals along the sub-scanning direction, which is orthogonal to the main scanning direction, from a nozzle  22  of one end side to a nozzle  22  of the other end side with a pitch that corresponds to a dot formation density. Additionally, it is also possible to seal the openings that are on the lower surface side of the spaces that correspond to the common liquid chambers with a member such as a compliance sheet that has a flexible property, for example, by joining the nozzle plate to a region of the communication substrate that is separated on the inner side from the common liquid chambers. If configured in this manner, it is possible to make the nozzle plate as small as possible. 
     As shown in  FIG. 2 , the piezoelectric device  14  of the present embodiment is unitized by laminating the pressure chamber formation substrate  29 , a vibration plate  31 , piezoelectric elements  32 , the sealing plate  33 , and a driving IC  34 , and is accommodated inside the accommodation space  17 . 
     The pressure chamber formation substrate  29  is a hard silicon plate material, and in the present embodiment, is prepared from a monocrystalline silicon substrate in which the crystal plane orientation of the outer surfaces (the upper surface and the lower surface) is set as ( 110 ). A plurality of spaces, which correspond to the pressure chambers  30 , are arranged in parallel in the pressure chamber formation substrate  29  along the nozzle row direction, as a result of portions being completely removed in the plate thickness direction by etching. The spaces configure the pressure chambers  30  as a result of the lower sections thereof being partitioned by the communication substrate  24 , and the upper sections thereof being partitioned by the vibration plate  31 . In addition, the spaces, that is, the pressure chambers  30  are formed in two rows to correspond to the nozzle rows that are formed in two rows. Each pressure chamber  30  is formed longitudinally in a direction that is orthogonal to the nozzle row direction, an individual communication channel  26  is in communication with the end section of one side in the longitudinal direction, and a nozzle communication channel  27  is in communication with the end section of the other side. 
     The vibration plate  31  is a thin film form member that has an elastic property, and is laminated onto an upper surface of the pressure chamber formation substrate  29  (a surface on a side that is opposite to the communication substrate  24 ). Upper section openings of the spaces that correspond to the pressure chambers  30  are sealed by the vibration plate  31 . In other words, the upper surfaces of the pressure chambers  30  are partitioned by the vibration plate  31 . Portions of the vibration plate  31  that correspond to the pressure chambers  30  (or to explain in more detail, the upper section openings of the pressure chambers  30 ) function as displacement sections that are displaced in a direction that becomes distant from or a direction that approaches the nozzles  22  in accordance with flexural deformation of the piezoelectric elements  32 . That is, regions of the vibration plate  31  that correspond to the upper section openings of the pressure chambers  30  correspond to driving regions in which flexural deformation is permitted. The cubic capacity of the pressure chambers  30  changes depending on the deformation (displacement) of the driving regions (displacement sections). Meanwhile, regions of the vibration plate  31  that are separated from the upper section openings of the pressure chambers  30  correspond to non-driving regions in which flexural deformation is inhibited. Additionally, the pressure chamber formation substrate  29  and the vibration plate  31  that is laminated thereon, correspond to the first substrate of the invention. 
     The piezoelectric elements  32  of the present embodiment, are so-called flexural mode piezoelectric elements. For example, in the piezoelectric elements  32 , a lower electrode layer, a piezoelectric body layer, and an upper electrode layer are sequentially laminated onto the vibration plate  31  in regions that correspond to each pressure chamber  30 . When an electric field depending on a difference in potential between the two electrodes is applied between the lower electrode layer and the upper electrode layer, the piezoelectric elements  32 , which are configuration in this manner, are flexurally deformed in a direction of becoming distant from or a direction of approaching the nozzles  22 . In addition, each piezoelectric element  32  is formed in two rows along the nozzle row direction to correspond to the pressure chambers  30 , which are arranged in parallel in two rows along the nozzle row direction. Furthermore, as shown in  FIG. 2 , driving wiring  37  is routed from each piezoelectric element  32  to further on an outer side than the piezoelectric elements  32  (that is, to a non-driving region). The driving wiring  37  is wiring that supplies a driving signal for driving the piezoelectric elements  32  to the piezoelectric elements  32 , and is disposed extending along a direction that is orthogonal to the nozzle row direction (that is, the parallel arrangement direction of the piezoelectric elements  32 ) from the piezoelectric elements  32  up to an end section of the vibration plate  31 . 
     As shown in  FIG. 2  and  FIG. 3 , the sealing plate  33  (equivalent to the second substrate of the invention) is a flat plate form substrate that is connected to the vibration plate  31  in a manner in which a space is formed between a first surface  35 , which is a lower surface, and the vibration plate  31  (or the piezoelectric elements  32 ). In the present embodiment, the sealing plate  33  and the pressure chamber formation substrate  29  (or to explain in more detail, the pressure chamber formation substrate  29 , which is equivalent to the first substrate of the invention and onto which the vibration plate  31  is laminated) are joined using a photosensitive adhesive  43  having both a thermosetting property and a photosensitive property. In addition, the sealing plate  33  is prepared from a monocrystalline silicon substrate in which the crystal plane orientation of the outer surfaces (the upper surface and the lower surface) is set as ( 110 ). Additionally, for example, the outer surfaces of the sealing plate  33  are covered by an insulation film  39 , which is formed from SiO 2 , SiN, or the like. 
     The driving IC  34 , which outputs driving signals for driving the piezoelectric elements  32 , is disposed on a second surface  36 , which is an upper surface of the sealing plate  33  (a surface on a side that is opposite to the first surface  35  (the surface on the piezoelectric element  32  side)). In addition, a plurality of resin core bumps  40 , which output the driving signals from the driving IC  34  to the piezoelectric element  32  side, are formed on the first surface  35  of the sealing plate  33 . As shown in  FIG. 2 , the resin core bumps  40  are respectively formed in a plurality along the nozzle row direction in a position that corresponds to one driving wiring  37  that is disposed extending from a row of one piezoelectric element  32 , and a position that corresponds to the other driving wiring  37  that is disposed extending from a row of the other piezoelectric element  32 . Further, each resin core bump  40  is connected to respective corresponding driving wiring  37 . 
     The resin core bumps  40  in the present embodiment have an elastic property, and are provided protruding toward a side of the vibration plate  31  in regions of the sealing plate  33  that face the driving wiring  37  (more specifically, terminal sections of the driving wiring  37 ). More specifically, as shown in  FIG. 2  and  FIG. 3 , the resin core bumps  40  are provided with a resin section  40   a  (equivalent to a resin of the invention) that is formed from an elastic body and is formed (provided in a protruding manner) on the first surface  35  of the sealing plate  33 , and an electrode layer  40   b  (equivalent to an electrode terminal of the invention) that is formed along the outer surface of a vibration plate  31  side of the corresponding resin section  40   a . The resin section  40   a  in the present embodiment, is formed into a protrusion along the nozzle row direction on the lower surface of the sealing plate  33 . In addition, the electrode layer  40   b  is formed in a plurality along the nozzle row direction to correspond to the piezoelectric elements  32 , which are arranged in parallel along the nozzle row direction. That is, the resin core bumps  40  are formed in a plurality along the nozzle row direction. 
     Further, the surfaces of the sides of the resin section  40   a  and the electrode layer  40   b  that face the driving wiring  37  (the lower surfaces of the resin core bumps  40 ) are formed curving in an arc shape toward a pressure chamber formation substrate  29  side in a cross-sectional view in a direction that is orthogonal the nozzle row direction. Such resin core bumps  40  are electrically connected to the driving wiring  37  that is on the pressure chamber formation substrate  29  as a result of a portion of the arc shape of the lower surfaces thereof being elastically deformed due to being pressed against corresponding driving wiring  37  (the terminal section of the driving wiring  37 ). That is, the electrode layers  40   b  and the driving wiring  37  (the terminal section of the driving wiring  37 ) are electrically connected in a state in which the resin section  40   a  is elastically deformed as a result of an increase in weight between the sealing plate  33  and the pressure chamber formation substrate  29  (a direction in which the two members come into contact with one another). The electrode layers  40   b  function as electrode terminals that perform electrical connection of wiring (lower surface side wiring  47 ) on a sealing plate  33  side and wiring of the pressure chamber formation substrate  29  side (the driving wiring  37 ). In this manner, it is possible to reliably connect the electrode layers  40   b  with a small increase in weight as a result of the resin sections  40   a  being elastically deformed. 
     Additionally, the resin sections  40   a  of the resin core bumps  40  are created by applying heat after patterning of a resin on the sealing plate  33 . More specifically, a resin film is formed on the lower surface of the sealing plate  33 , and the resin is patterned in a position that corresponds to the resin section  40   a  using etching, or the like. Thereafter, for example, the resin section  40   a  in which a tip end portion is curved, is formed by rounding the angles thereof by heating to approximately 250° C. Additionally, for example, a resin that has an elastic property, and is formed from a polyimide resin, a phenol resin, an epoxy resin, or the like, can be used as the resin sections  40   a . In addition, a metal that is formed from gold (Au), titanium (Ti), aluminum (Al) chromium (Cr), nickel (Ni), copper (Cu), an alloy thereof, or the like, can be used as the electrode layers  40   b.    
     In addition, each electrode layer  40   b  corresponds to lower surface side wiring  47  that, on the lower surface of the sealing plate  33 , is separated and disposed extending on the inner side (the piezoelectric element  32  side) along a direction that is orthogonal to the nozzle row direction from above the resin section  40   a . The lower surface side wiring  47  is wiring that connects the resin core bumps  40  and the penetration wiring  45  (to be described later), and is disposed extending from a position that corresponds to the electrode layer  40   b  above the resin section  40   a  to a position that corresponds to the penetration wiring  45 . In other words, a portion of the lower surface side wiring  47  that is formed on the lower surface of the sealing plate  33  forms the electrode layer  40   b  of the resin core bump  40  as a result of being disposed extending along a direction that is orthogonal to the nozzle row direction from a position that corresponds to the penetration wiring  45  up to above the resin section  40   a.    
     Furthermore, as shown in  FIG. 2 , a plurality (four in the present embodiment) of pieces of power source wiring  53  that supplies power source voltages, and the like (for example, VDD1 (a power source of a low voltage circuit), VDD2 (a power source of a high voltage circuit), VSS1 (a power source of a low voltage circuit), and VSS2 (a power source of a high voltage circuit)) to the driving IC  34 , are formed in a central section on the upper surface of the sealing plate  33  (a region that is separated from regions that correspond to the resin core bumps  40 ). The power source wiring  53  is formed from upper surface side embedded wiring  50 , which is embedded in the upper surface of the sealing plate  33 , and upper surface side wiring  46 , which is laminated in a manner that covers the upper surface side embedded wiring  50 . Power source bump electrodes  56  of the corresponding driving IC  34  are electrically connected to the top of the upper surface side wiring  46  of the power source wiring  53 . Additionally, the upper surface side embedded wiring  50  is formed from a metal (a conductor) such as copper (Cu). 
     In addition, as shown in  FIG. 2  and  FIG. 3 , driving bump electrodes  57  of the driving IC  34  are connected, and connection terminals  54  into which signals from the driving IC  34  are input, are formed, in regions of both end sides on the upper surface of the sealing plate  33  (to explain in more detail, regions that are separated on the outer sides from regions in which the power source wiring  53  is formed, and that correspond to the resin core bumps  40 ). The connection terminals  54  are formed in a plurality along the nozzle row direction corresponding to the piezoelectric elements  32 . The upper surface side wiring  46  is disposed extending toward the inner side (the piezoelectric element  32  side) from each connection terminal  54 . The upper surface side wiring  46  is connected to corresponding lower surface side wiring  47  via the penetration wiring  45 . Additionally, the configuration of the penetration wiring  45  will be mentioned in more detail later. 
     The driving IC  34 , which is disposed on the sealing plate  33 , is an IC chip that outputs signals for driving the piezoelectric elements  32 , and is laminated on the second surface  36  of the sealing plate  33  using an adhesive  59  such as an anisotropic conductive film (ACF). As shown in  FIG. 2  and  FIG. 3 , the power source bump electrodes  56 , which are connected to the power source wiring  53 , and the driving bump electrodes  57 , which are connected to the connection terminals  54 , are provided in a plurality along the nozzle row direction on the surface of the sealing plate  33  side of the driving IC  34 . The power source bump electrodes  56  are terminals that take in a voltage (electric power) from the power source wiring  53  to a circuit inside the driving IC  34 . In addition, the driving bump electrodes  57  are terminals that output signals that drives each piezoelectric element  32 . The driving bump electrodes  57  in the present embodiment are formed in two rows on both sides of the power source bump electrodes  56  to correspond to a row of the piezoelectric elements  32 , which are arranged in parallel in two rows. 
     Further, in the recording head  3  having the above-mentioned configuration, ink is introduced from the ink cartridges  7  to the pressure chambers  30  through the liquid introduction paths  18 , the common liquid chambers  25  and the individual communication channels  26 . In this state, the piezoelectric elements  32  are driven and pressure fluctuations are generated in the pressure chambers  30  by supplying driving signals from the driving IC  34  to the piezoelectric elements  32  through each piece of wiring that is formed on the sealing plate  33 . The recording head  3  ejects ink droplets from the nozzles  22  through the nozzle communication channels  27  using the pressure fluctuations. 
     Next, the configuration of the penetration wiring  45  will be described in detail. As shown in  FIG. 3  and  FIG. 4 , the penetration wiring  45  is wiring that relays between the first surface  35  and the second surface  36  of the sealing plate  33  (or more specifically, the lower surface side wiring  47  and the upper surface side wiring  46 ), and extends in a direction (that is, a plate thickness direction) that is perpendicular to the first surface  35 . The penetration wiring  45  is formed from a conductor such as a metal, and an inner portion of a penetration hole  44 , which penetrates through the sealing plate  33  in the plate thickness direction, is filled by the penetration wiring  45 . In other words, the penetration wiring  45  is formed from a conductor, which is formed in the inner portion of the penetration hole  44 , which penetrates through the sealing plate  33  in the plate thickness direction. Additionally, in the conductor that corresponds to the penetration wiring  45  of the present embodiment, copper (Cu) is used since it is possible to easily manufacture using an electrolytic plating technique. 
     As shown in  FIG. 4 , the cross-sectional area of the penetration hole  44  on a surface (that is, a surface that is perpendicular to a planar direction of the first surface  35 , or the plate thickness direction) that is parallel to the first surface  35  increases from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 . In other words, the cross-sectional area of the penetration hole  44  from the first surface  35  up to a predetermined range (a formation range of a first recessed portion  61  which will be described later) in the plate thickness direction, and the cross-sectional area from the second surface  36  up to a predetermined range (a formation range of a second recessed portion  62  which will be described later) in the plate thickness direction are greater than the cross-sectional area of the penetration hole  44  in a remaining range (a formation range of a penetration channel  63 , which will be described later). Therefore, the cross-sectional area of the penetration wiring  45 , with which the penetration hole  44  is filled, on the surface that is parallel to the first surface  35  also increases from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 . More specifically, as shown in  FIG. 4 , the penetration hole  44  is provided with the first recessed portion  61  in which a portion of the sealing plate  33  on the first surface  35  is removed up to midway in the plate thickness direction, the second recessed portion  62  in which a portion of the sealing plate  33  on the second surface  36  is removed up to midway in the plate thickness direction, and the penetration channel  63 , the cross-sectional area on the surface (a surface that is perpendicular to the plate thickness direction) that is parallel to the first surface  35 , of which is smaller than those of the first recessed portion  61  and the second recessed portion  62 . The first recessed portion  61  and the second recessed portion  62  in the present embodiment are partitioned by a side wall that extends in a direction that is perpendicular to the first surface  35  (or the second surface  36 ), and a bottom surface that is parallel to the first surface  35  (or the second surface  36 ). Further, the cross-sectional areas of both recessed portions  61  and  62  are aligned to be substantially the same area. The penetration channel  63  is an oblong hole that communicates between a bottom surface of the first recessed portion  61  and a bottom surface of the second recessed portion  62 . An upper end of the penetration channel  63  in the present embodiment is open to a central portion of the bottom surface of the first recessed portion  61 , and a lower end thereof is open to a central portion of the bottom surface of the second recessed portion  62 . 
     Further, the penetration wiring  45 , with which the inner portion of the penetration hole  44  is filled, is formed from a first end portion  65 , which is formed inside the first recessed portion  61 , a second end portion  66 , which is formed inside the second recessed portion  62 , and connection wiring  67 , which is formed inside the penetration channel  63 . That is, the penetration wiring  45  is provided with the first end portion  65 , which extends from the first surface  35  of the sealing plate  33  up to midway in the plate thickness direction, the second end portion  66 , which extend from the second surface  36  of the sealing plate  33  up to midway in the plate thickness direction, and the connection wiring  67 , which extends from the first end portion  65  up to the second end portion  66 . In other words, the penetration wiring  45  is provided with the first end portion  65 , which is provided on a first surface  35  side, the second end portion  66 , which is provided on a second surface  36  side, and the connection wiring  67 , which connects the first end portion  65  and the second end portion  66 . Further, the cross-sectional area of the connection wiring  67  on the surface that is parallel to the first surface  35  is formed to be smaller than the cross-sectional areas of the first end portion  65  and the second end portion  66  on the surface that is parallel to the first surface  35 . 
     Additionally, for example, the length L (that is, the thickness of the sealing plate  33 ) of the penetration hole  44  in the present embodiment is set to approximately 300 μm to 400 μm. In addition, for example, the opening diameter D (the opening diameter of the first recessed portion  61  and the opening diameter of the second recessed portion  62 ) of the penetration hole  44  is set to be approximately 20 μm to approximately 30 μm depending on the pitch of the nozzles  22 . That is, the aspect ratio L/D of the penetration hole  44  is set to be approximately 10 or more. Additionally, the inner walls (that is, the side wall and the bottom surface of the first recessed portion  61 , the side wall and the bottom surface of the second recessed portion  62 , and the side wall of the penetration channel  63 ) of the penetration channel  63  are covered using the insulation film  39  in the same manner as the outer surfaces of the sealing plate  33 . Further, the penetration wiring  45  is formed on the insulation film  39 . That is, the insulation film  39  is formed between the penetration wiring  45  and the penetration hole  44 . Further, a portion of the penetration wiring  45  that is exposed to an opening portion of the first recessed portion  61  is covered by the lower surface side wiring  47 . In addition, a portion of the penetration wiring  45  that is exposed to an opening section of the second recessed portion  62  is covered by the upper surface side wiring  46 . That is, the upper surface side wiring  46 , which is disposed extending from the connection terminal  54 , and a lower surface side wiring  47 , which is disposed extending from a corresponding resin core bump  40 , are electrically connected by the penetration wiring  45 . 
     In this manner, since the cross-sectional areas of the penetration hole  44  and the penetration wiring  45  increase toward the first surface  35  and the second surface  36 , it is even possible to suppress a circumstance in which the penetration wiring  45  sticks out (protrudes) to an outer side from the penetration hole  44  when heat, an external force, or the like, is applied to the sealing plate  33 . For example, in a heating treatment when forming the resin sections  40   a  of the resin core bumps  40  on the sealing plate  33 , there is a concern that a force will work in a direction that ejects the penetration wiring  45  from the penetration hole  44  as a result of a difference in the thermal expansion coefficients (the linear expansion coefficients) of the penetration wiring  45  and the sealing plate  33 . Even if such a force is at work, since a conductor portion of the penetration wiring  45 , with which the inside of the first recessed portion  61  is filled, or a conductor portion of the penetration wiring  45 , with which the second recessed portion  62  is filled, are not inserted into the penetration channel  63 , these components act as retainers, and therefore, it is possible to suppress a circumstance in which the penetration wiring  45  sticks out to the outer side from the penetration hole  44 . In addition, since sticking out (protruding) of the penetration wiring  45  is physically suppressed by the forms of the penetration hole  44  and the penetration wiring  45 , it is not necessary to form an adhesive layer for causing the conductor, which corresponds to the penetration wiring  45 , to adhere to the inside of the penetration hole  44 . In particular, even in a case in which the aspect ratio L/D of the penetration hole  44  is large, and it is not possible to form an adhesive layer in an inner portion of the penetration hole  44 , it is possible to fix the penetration wiring  45  to the inside of the penetration hole  44 . Furthermore, since the penetration wiring  45  is disposed extending in a direction that is perpendicular to the first surface  35 , formation of the penetration wiring  45  is facilitated, and therefore, and manufacture of the sealing plate  33  is further facilitated. 
     Next, a manufacturing method of the penetration wiring  45  will be described.  FIG. 5  to  FIG. 8  are cross-sectional views that describe a manufacturing process of the penetration wiring  45 . Firstly, as shown in  FIG. 5 , in a first recessed portion formation process, the first recessed portion  61  is formed by removing a portion of the sealing plate  33 , which is formed from a monocrystalline silicon substrate, on the first surface  35  up to midway in the plate thickness direction. More specifically, a mask layer, in which a position of the sealing plate  33  that corresponds to the first recessed portion  61 , and the like, is open, is formed on the first surface  35  of the sealing plate  33  by carrying out an exposure process and a developing process, and thereafter, the first recessed portion  61  is formed by digging through the sealing plate  33  using a dry etching technique. Once the first recessed portion  61  is formed, the mask layer is removed. Next, in a second recessed portion formation process, the second recessed portion  62  is formed by removing a portion of the sealing plate  33  on the second surface  36  up to midway in the plate thickness direction. That is, in the same manner as the first recessed portion formation process, a mask layer, in which a position of the sealing plate  33  that corresponds to the second recessed portion  62 , and the like, is open, is formed on the second surface  36  by carrying out an exposure process and a developing process, and thereafter, the second recessed portion  62  is formed by digging through the sealing plate  33  using a dry etching technique. Once the second recessed portion  62  is formed, the mask layer is removed. Additionally, either one of the first recessed portion formation process and the second recessed portion formation process may be performed first. 
     Once the first recessed portion  61  and the second recessed portion  62  are formed in the sealing plate  33 , as shown in  FIG. 6 , the penetration channel  63 , which penetrates through the first recessed portion  61  and the second recessed portion  62 , is formed. That is, the penetration hole  44 , which penetrates through the sealing plate  33 , is formed. In this instance, the penetration channel  63  is formed so that the cross-sectional area on the surface that is parallel to the first surface  35  (the surface that is perpendicular to the plate thickness direction) so as to be smaller than those of the first recessed portion  61  and the second recessed portion  62 . For example, this kind of penetration channel  63  can be formed using dry etching, laser, or the like, such as Deep RIE. In the present embodiment, a laser machining technique is used since it is possible to easily manufacture a penetration channel  63  having a high aspect ratio. Further, once the penetration hole  44  is formed, as shown in  FIG. 7 , the insulation film  39  is formed on the inner walls of the first surface  35  and the second surface  36  of the sealing plate  33  and the penetration hole  44 . The insulation film  39  in the present embodiment is formed from a thermally oxidized film (SiO 2 ), and is formed by performing a thermal oxidation process. 
     Further, lastly, as shown in  FIG. 8 , in the penetration wiring formation process, a conductor (copper (Cu) in the present embodiment), which corresponds to the penetration wiring  45  (that is, the first end portion  65 , the second end portion  66  and the connection wiring  67 ) is formed in the inner portion of the penetration hole  44  (that is, the first recessed portion  61 , the second recessed portion  62  and the penetration channel  63 ) using an electrolytic plating technique. In addition, in the present embodiment, the penetration wiring  45  is formed without forming the adhesive layer (the seed layer) in the inner portion of the penetration hole  44 . Various methods can be adopted as such a method. For example, the adhesive layer (the seed layer) is formed at one opening edge of either the first recessed portion  61  or the second recessed portion  62  using a sputtering technique, and the one recessed portion on which the adhesive layer is formed is blocked using the conductor by growing the conductor on the adhesive layer using an electrolytic plating technique. Further, the inside of the penetration hole  44  is filled with the conductor by setting the conductor that blocked the recessed portion as a core, and growing the conductor from the one recessed portion up to the other recessed portion. Additionally, conductor that is deposited further on the outer sides than the first surface  35  and the second surface  36  of the sealing plate  33  is removed using a Chemical Mechanical Polishing (CMP) technique, or the like. As a result of this, penetration wiring  45  such as that shown in  FIG. 8  is formed. 
     As a result of this kind of method, it is possible to easily create penetration wiring  45  in which the cross-sectional area on a surface that is parallel to the first surface  35 , increases from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 . As a result of this, in a subsequent manufacturing process, a specification environment of the printer  1 , or the like, it is even possible to suppress a circumstance in which the penetration wiring  45  sticks out (protrudes) to an outer side from the penetration hole  44  when heat, an external force, or the like, is applied to the sealing plate  33 . In addition, since the penetration wiring  45  is formed using an electrolytic plating technique, it is even possible to reliably form the conductor inside the penetration channel  63  in a case in which the aspect ratio of the penetration channel  63  is high. Furthermore, since the first recessed portion  61  and the second recessed portion  62  are formed using a dry etching technique, it is possible to form the first recessed portion  61  and the second recessed portion  62  with high accuracy. Further, since the penetration wiring  45  is formed using an electrolytic plating technique such as that above, it is possible to form the penetration wiring  45  without forming an adhesive layer in the inner portion of the penetration hole  44 . As a result of this, even in a case in which the aspect ratio is high and it is difficult to form the adhesive layer inside the penetration hole  44 , it is possible to form the penetration wiring  45  stably. 
     As is also disclosed in JP-A-2011-111996, it is it is difficult to form an adhesive layer having a high coverage (covering) ratio in a case in which the aspect ratio is 3 or more in a penetration hole of the related art. As a result of this, it is not possible to ensure an adhesive force even if the penetration wiring is formed inside the penetration hole using an electrolytic plating technique, and there is a concern that the penetration wiring will stick out to the outer side from the penetration hole when heat, an external force, or the like is applied to a sealing plate. Therefore, it is preferable that the invention is adopted in a case in which penetration wiring is formed in a penetration hole in which the aspect ratio L/D is 3 or more. In addition, it is preferable that the penetration wiring  45  is formed using the above-mentioned electrolytic plating technique in which an adhesive layer is not formed, in a case in which an aspect ratio L′/D′ of the connection wiring  67  (L′ is the length of the connection wiring  67  and D′ is the opening diameter of the connection wiring  67 : refer to  FIG. 4 ) is 3 or more. 
     Furthermore, even supposing it is possible to form an adhesive layer inside a penetration hole, in a case in which the conductor is grown inside a penetration hole having a high aspect ratio L/D, there is a concern that a void will be generated within the penetration wiring. However, in the present embodiment, since the penetration wiring  45  is formed in an inner portion of the penetration hole  44  using an electrolytic plating technique in which an adhesive layer is not formed, it is possible to suppress the generation of such a void. In addition, even if formed using such a method, since the cross-sectional area of the penetration wiring  45  is configured to increase from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 , it is possible to stably fix the penetration wiring  45  inside the penetration hole  44 . 
     Incidentally, the shapes of the penetration hole  44  and the penetration wiring  45  are is not limited to those of the above-mentioned first embodiment. The penetration hole  44  and the penetration wiring  45  may have any shape as long as the cross-sectional areas of penetration hole  44  and the penetration wiring  45  on the surface that is parallel to the first surface  35  increases from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 . For example, in a second embodiment that is shown in  FIG. 9 , both end portions (respective portions of predetermined ranges in the plate thickness direction from the first surface  35  and the second surface  36 ) of the penetration hole  44  are configured to gradually increase in diameter toward the first surface  35  and the second surface  36 . In other words, the cross-sectional areas of penetration hole  44  and the penetration wiring  45  on the surface that is parallel to the first surface  35  is continuously enlarged from midway in the plate thickness direction of the sealing plate  33  toward the first surface  35  and the second surface  36 . 
     As shown in  FIG. 9 , in the same manner as the first embodiment, the penetration channel  63  in the present embodiment is an oblong hole that links the first recessed portion  61  and the second recessed portion  62 . In addition, in the present embodiment, the opening area of the first recessed portion  61  on the first surface  35  side, and the opening area of the second recessed portion  62  on the second surface  36  side, are formed to be larger than the cross-sectional area of the penetration channel  63  in the same manner as the first embodiment. Further, the first recessed portion  61  is configured to gradually decrease in diameter toward the penetration channel  63  from the opening on the first surface  35  side. In other words, the cross-sectional area of the first recessed portion  61  on the surface that is parallel to the first surface  35  gradually increases toward the first surface  35  from the penetration channel  63 . That is, the side walls of the first recessed portion  61  are inclined toward an opening edge of the penetration channel  63  on the first recessed portion  61  side from an opening edge on the first surface  35  side. Further, as a result of this, the cross-sectional area of the first end portion  65 , with which the first recessed portion  61  is filled, on the surface that is parallel to the first surface  35 , also gradually increases toward the first surface  35  from the connection wiring  67 , with which the penetration channel  63  is filled. In the same manner, the second recessed portion  62  is configured to gradually decrease in diameter toward the penetration channel  63  from the opening on the second surface  36  side. In other words, the cross-sectional area of the second recessed portion  62  on the surface that is parallel to the first surface  35  gradually increases toward the second surface  36  from the penetration channel  63 . That is, the side walls of the second recessed portion  62  are inclined toward an opening edge of the penetration channel  63  on the second recessed portion  62  side from an opening edge on the second surface  36  side. Further, as a result of this, the cross-sectional area of the second end portion  66 , with which the second recessed portion  62  is filled, on the surface that is parallel to the first surface  35 , also gradually increases toward the second surface  36  from the connection wiring  67 . Additionally, since the other configurations are the same as those of the above-mentioned first embodiment, description thereof will be omitted. 
     As a result of this, in comparison with the first recessed portion  61 , the second recessed portion  62 , and the like in the first embodiment, it is possible to reduce an angle that is formed on the inner walls of the penetration hole  44 . As a result of this, it is possible to reduce a portion in which an electric field, stress, and the like, concentrate, and therefore, it is possible to improve the reliability of the sealing plate  33 . Further, since such first recessed portion  61  and the second recessed portion  62  can be created using a wet etching technique that differs from that of the first embodiment, the formation of the penetration wiring  45  is facilitated. A specific manufacturing method of the penetration wiring  45  will be described. 
       FIG. 10  to  FIG. 13  are cross-sectional views that describe a manufacturing process of the penetration wiring  45 . Firstly, as shown in  FIG. 10 , in a first recessed portion formation process, the first recessed portion  61  is formed by removing a portion of the sealing plate  33 , which is formed from a monocrystalline silicon substrate, on the first surface  35  up to midway in the plate thickness direction. More specifically, a mask layer, in which a position that corresponds to the first recessed portion  61 , and the like, is open, is formed on the first surface  35  of the sealing plate  33  by carrying out an exposure process and a developing process, and thereafter, the first recessed portion  61  is formed by digging through the sealing plate  33  using a wet etching technique. In the present embodiment, since a monocrystalline silicon substrate in which the crystal plane orientation of outer surfaces is set as ( 110 ), is dug through using a wet etching technique, as shown in  FIG. 10 , a first recessed portion  61  that decreases in diameter toward the second surface  36  side, is formed. Once the first recessed portion  61  is formed, the mask layer is removed. Next, in a second recessed portion formation process, the second recessed portion  62  is formed by removing a portion of the sealing plate  33  on the second surface  36  up to midway in the plate thickness direction. That is, in the same manner as the first recessed portion formation process, a mask layer, in which a position of the sealing plate  33  that corresponds to the second recessed portion  62 , and the like, is open, is formed on the second surface  36  by carrying out an exposure process and a developing process, and thereafter, the second recessed portion  62  is formed by digging through the sealing plate  33  using a wet etching technique. As a result of this, in the same manner as the first recessed portion  61 , a second recessed portion  62  that decreases in diameter toward the first surface  35  side, is formed. Once the second recessed portion  62  is formed, the mask layer is removed. Additionally, either one of the first recessed portion formation process and the second recessed portion formation process may be performed first. 
     Once the first recessed portion  61  and the second recessed portion  62  are formed in the sealing plate  33 , in the same manner as the first embodiment, the penetration channel  63 , which penetrates through the first recessed portion  61  and the second recessed portion  62 , is formed. In the present embodiment, a penetration channel  63  that penetrates through a central portion (a leading end portion that decreases in diameter) of a bottom portion of the first recessed portion  61 , and a central portion (a leading end portion that decreases in diameter) of a bottom portion of the second recessed portion  62 , is formed. Additionally, the method of formation of the penetration channel  63  is the same as the first embodiment. As a result of this, as shown in  FIG. 11 , a penetration channel  63  in which the cross-sectional area (or more specifically, an average value of the cross-sectional areas) on the surface (the surface that is perpendicular to the plate thickness direction) that is parallel to the first surface  35 , is smaller than those of the first recessed portion  61  and the second recessed portion  62 , is formed. Further, once the penetration hole  44  is formed, as shown in  FIG. 12 , the insulation film  39  is formed on the inner walls of the first surface  35  and the second surface  36  of the sealing plate  33  and the penetration hole  44 . In the present embodiment, the insulation film  39  is also formed by performing a thermal oxidation process. Lastly, as shown in  FIG. 13 , in the penetration wiring formation process, a conductor (copper (Cu) in the present embodiment), which corresponds to the penetration wiring  45  (that is, the first end portion  65 , the second end portion  66  and the connection wiring  67 ) is formed in the inner portion of the penetration hole  44  (that is, the first recessed portion  61 , the second recessed portion  62  and the penetration channel  63 ) using an electrolytic plating technique. Additionally, since the method that forms the conductor inside the penetration hole  44  using an electrolytic plating technique is the same as that of the above-mentioned first embodiment, description thereof will be omitted. 
     In this manner, in the present embodiment, since the first recessed portion  61  and the second recessed portion  62  are formed using a wet etching technique, it is possible to form the first recessed portion  61  and the second recessed portion  62  in a short period of time. In addition, since a monocrystalline silicon on which etching proceeds in a direction that is inclined with respect to the first surface  35 , is used as the sealing plate  33 , it is possible to configure inner walls of the first recessed portion  61  and the second recessed portion  62  as inclined surfaces. As a result of this, it is possible to reduce an angle at which it is easy for an electric field and stress to concentrate. 
     Additionally, in the above-mentioned first embodiment, in the first recessed portion formation process and the second recessed portion formation process, the first recessed portion  61  and the second recessed portion  62  are formed using a dry etching technique, but the invention is not limited to this configuration. In addition, in the above-mentioned second embodiment, in the first recessed portion formation process and the second recessed portion formation process, the first recessed portion  61  and the second recessed portion  62  are formed using a wet etching technique, but the invention is not limited to this configuration. For example, formation may be performed using a dry etching technique in either one of the first recessed portion formation process or the second recessed portion formation process, and using a wet etching technique in the other process. 
     In addition, in the above-mentioned first embodiment and second embodiment, only the insulation film  39  is provided between the inner wall of the penetration hole  44  and the penetration wiring  45 , which is a conductor, but the invention is not limited to this configuration. For example, a diffusion prevention film, which prevents diffusion of the conductor, may be formed between the penetration wiring  45  and the insulation film  39 . For example, the diffusion prevention film is formed using titanium nitride (TiN), or the like. Additionally, in a case in which a diffusion prevention function of the insulation film  39  is sufficient due to the specifications of a product, or the like, in the manner of the present embodiment, a diffusion prevention film need not be provided. 
     Furthermore, the configuration of the piezoelectric device  14  is not limited to a configuration in which the driving IC  34  is laminated on the sealing plate  33  in the manner of the first embodiment. For example, a configuration in which a driving IC is not laminated on a sealing plate and a direct driving circuit is formed on the outer surface of a sealing plate, may also be used. In other words, it is possible to use a driving IC in which a driving circuit is formed as a sealing plate. In addition to this, a configuration in which a Tape Carrier Package (TCP) in which a driving IC is mounted, is connected to an upper surface of a sealing plate, may also be used. 
     Further, description is given above using the recording head  3  as an example of a type of liquid ejecting head, but the invention can also be applied to other liquid ejecting heads as long as they are provided with penetration wiring that penetrates through a substrate. For example, it is also possible to apply the invention to color material discharging heads that are used in the manufacturing of color filters such as liquid crystal displays, electrode material discharging heads that are used in electrode formation such as organic Electro Luminescence (EL) displays, Field Emission Displays (FEDs), and the like, and living organic matter discharging heads that are used in the manufacturing of biochips (biochemical elements), and the like.