Patent Publication Number: US-11020970-B2

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

Description:
The present application is based on, and claims priority from JP Application Serial Number 2019-035568, filed Feb. 28, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a liquid ejecting head including an electric substrate pertaining to driving of a drive element, a liquid ejecting apparatus, and a method of manufacturing the liquid ejecting head. 
     2. Related Art 
     A liquid ejecting apparatus includes a liquid ejecting head and is an apparatus that ejects various liquids from the ejecting head. While the above liquid ejecting apparatus includes an image recording apparatus such as, for example, an ink jet printer or an ink jet plotter, in recent years, taking advantage of the strong point of being able to accurately apply a very small amount of liquid to a predetermined position, the liquid ejecting apparatus is applied to various manufacturing apparatuses. For example, the liquid ejecting apparatus is applied to a display manufacturing apparatus that manufactures a color filter of a liquid crystal display and the like, an electrode forming apparatus that forms electrodes of an electroluminescence (EL) display and a field emission display (FED), and a chip manufacturing apparatus that manufactures biochips. Furthermore, in a recording head for an image recording apparatus, liquid ink is ejected, and in a coloring material ejecting head for a display manufacturing apparatus, solution of various colors, namely, red (R), green (G), and blue (B) is ejected. Furthermore, in an electrode material ejecting head for an electrode forming apparatus, a liquid electrode material is ejected, and in a bio-organic matter ejecting head for a chip manufacturing apparatus, solution of a bio-organic matter is ejected. 
     The liquid ejecting head is configured of layers of a plurality of constituting members. For example, a liquid ejecting head disclosed in JP-A-2015-139939 is configured of layers including a head body that includes nozzles and the like that eject a liquid, a downstream flow path member that holds the head body and that supplies ink to the head body, a relay substrate (in other words, an electric substrate) held on the downstream flow path member, and an upstream flow path member. In such a configuration, positioning protruded portions protrude from a surface of the downstream flow path member on which the relay substrate is held. The position of the relay substrate with respect to the flow path member is set by inserting and fitting the protruded portions into recessed portions (in other words, through holes) in the relay substrate. Furthermore, pipe-shaped protrusions serving as upstream end portions of the inner flow paths protrude from the surface of the relay substrate on which the flow path member is held, and corresponding to the above, flow path insertion holes through which the protrusions are inserted are provided in the relay substrate. 
     In the configuration described above, since the through holes through which the projections for the ink supplying flow paths are inserted, and the positioning through holes are provided in the relay substrate, circuit wiring and disposing of chips cannot be performed in the above area where the holes are formed. Accordingly, the circuit wiring and the like are formed at positions avoiding the area where the holes are formed and, as a result, the electric substrate becomes large in size and, consequently, a problem in that the liquid ejecting head becomes large in size occurs. 
     SUMMARY 
     The liquid ejecting head according to the present disclosure has been proposed in view of the above issue and includes a plurality of nozzles that eject a liquid, a flow path member including flow paths that supply the liquid to the nozzles, and an electric substrate layered on the flow path member in a first direction. The flow path member includes a plurality of pipes that protrude in the first direction from a surface on a side on which the electric substrate is layered, and the flow paths is formed inside the pipes. A plurality of through holes through which the pipes are inserted are provided in the electric substrate, and the plurality of pipes include a first pipe that includes a contact surface that contacts an internal circumferential surface of the through hole, and a second pipe that includes a contact surface that contacts an internal circumferential surface of the through hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a configuration of a liquid ejecting apparatus. 
         FIG. 2  is a plan view of a liquid ejecting head. 
         FIG. 3  is a cross-sectional view taken along line III-III in  FIG. 2 . 
         FIG. 4  is a cross-sectional view of a vicinity of a flow path unit. 
         FIG. 5  is a plan view of a vicinity of a third pipe and a through hole in an electric substrate. 
         FIG. 6  is a cross-sectional view taken along line VI-VI in  FIG. 5 . 
         FIG. 7  is a plan view illustrating a configuration of a vicinity of a first positioning through hole and a first pipe according to the electric substrate. 
         FIG. 8  is a cross-sectional view taken along line VIII-VIII in  FIG. 7 . 
         FIG. 9  is a plan view illustrating a configuration of a vicinity of a second positioning through hole and a second pipe according to the electric substrate. 
         FIG. 10  is a cross-sectional view taken along line X-X in  FIG. 9 . 
         FIG. 11  is a plan view illustrating a configuration of a first pipe and a first positioning through hole according to a first modification. 
         FIG. 12  is a plan view illustrating a configuration of a second pipe and a second positioning through hole according to the first modification. 
         FIG. 13  is a plan view illustrating a configuration of a second pipe and a second positioning through hole according to a second modification. 
         FIG. 14  is a plan view illustrating a configuration of a first pipe according to a third modification. 
         FIG. 15  is a plan view illustrating a configuration of a first positioning through hole according to a fourth modification. 
         FIG. 16  is a plan view illustrating a configuration of a second positioning through hole according to a fourth modification. 
         FIG. 17  is a plan view of a liquid ejecting head according to a second exemplary embodiment. 
         FIG. 18  is a plan view of a liquid ejecting head according to a third exemplary embodiment. 
         FIG. 19  is a plan view of a liquid ejecting head according to a modification of the third exemplary embodiment. 
         FIG. 20  is a plan view of a liquid ejecting head according to a fourth exemplary embodiment. 
         FIG. 21  is a plan view of a liquid ejecting head according to a first modification of the fourth exemplary embodiment. 
         FIG. 22  is a plan view of a liquid ejecting head according to a second modification of the fourth exemplary embodiment. 
         FIG. 23  is a plan view of a liquid ejecting head according to a third modification of the fourth exemplary embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, exemplary embodiments for carrying out the present disclosure will be described with reference to the drawings. Note that in the exemplary embodiments described below, various limitations are described as specific examples suitable for the present disclosure; however, the scope of the present disclosure is not limited to the configurations described below unless there is a description particularly implying that the present disclosure is limited thereby. Furthermore, an ink jet printer in which an ink jet recording head, which is a type of liquid ejecting head, is mounted is described hereinafter as an example of the liquid ejecting apparatus of the present disclosure. 
     Referring first to  FIG. 1 , a configuration of a liquid ejecting apparatus  1  according to the present exemplary embodiment will be described. The liquid ejecting apparatus  1  is an apparatus that records an image and the like on a surface of a medium  2 , such as recording paper, by ejecting liquid ink. Hereinafter, among an X direction, a Y direction, and a Z direction that are orthogonal to each other, the Y direction (corresponding to a second direction in the present disclosure) is a transport direction of the medium  2  or is a direction of relative movement between the medium  2  and a liquid ejecting head  3 , the X direction (corresponding to a third direction of the present disclosure) is a direction orthogonal to the transport direction, and the Z direction (corresponding to a first direction in the present disclosure) is a direction orthogonal to an XY plane. Furthermore, a tip side of an arrow, the arrow depicting a direction, is referred to as a (+) direction and a base end side of the arrow, the arrow depicting a direction, is referred to as a (−) direction. 
     The liquid ejecting apparatus  1  includes the liquid ejecting head  3 , a carriage  4  to which the liquid ejecting head  3  is attached, and a carriage moving mechanism  5  that reciprocates the carriage  4  in a main scanning direction (the X direction) that is a width direction of the medium  2 . Furthermore, the liquid ejecting apparatus  1  includes a transport mechanism and the like (not shown) that transports the medium  2  in the transport direction (the Y direction). Note that the ink described above is a kind of liquid of the present disclosure and is stored in ink cartridges  7  serving as liquid storing members. The ink cartridges  7  are mounted on the liquid supplying unit  10  (described later) of the liquid ejecting head  3  in a detachable manner. Note that a configuration can be adopted in which the ink cartridges  7  are disposed on a main body side of the liquid ejecting apparatus  1  and in which the ink is supplied to the liquid ejecting head  3  from the ink cartridges  7  through ink supply tubes. 
       FIG. 2  is a plan view of the liquid ejecting head  3  viewed in the +Z direction, and  FIG. 3  is a cross-sectional view taken along line III-III in  FIG. 2 . Furthermore,  FIG. 4  is a cross-sectional view illustrating a configuration of a vicinity of a flow path unit  9  of the liquid ejecting head  3 . Note that in  FIG. 2 , an illustration of the liquid supplying unit  10  is omitted, and in  FIG. 3 , the liquid supplying unit  10  is depicted by a broken line. Furthermore, an illustration of a head cover  18  is omitted in  FIG. 4 . Hereinafter, when assuming that a nozzle surface (in other words, a nozzle plate  30  described later) in which nozzles  37  of the liquid ejecting head  3  are formed is a surface parallel to the XY plane described above, the Z direction is a direction orthogonal to the nozzle surface. 
     The liquid ejecting head  3  according to the exemplary embodiment includes the liquid supplying unit  10 , a head case  11 , and an electric substrate  14 , which may also be referred to as a circuit substrate, disposed between the liquid supplying unit  10  and the head case  11 . The liquid supplying unit  10  is a structure including flow paths in which the ink flows, filters that perform filtration of the ink, and other members. The liquid supplying unit  10  distributes the ink stored in the ink cartridges  7  to introduction flow paths of the head case  11  through the internal flow paths. 
     The head case  11  is a synthetic resin member in which accommodation chambers  20  that accommodate actuator units  13  therein and in which introduction flow paths  17  that are liquid flow paths that introduce the ink supplied from the supplying unit  10  to the flow path unit  9  are formed. The head case  11  is a type of flow path member according to the disclosure. The head cover  18  that is formed of metal such as stainless steel and in which an opening portion that exposes the nozzle surface of the flow path unit  9  is provided is, after the flow path unit  9  has been joined thereto, joined to an undersurface of the head case  11  in the Z direction. Furthermore, the electric substrate  14  and the liquid supplying unit  10  are mounted on an upper surface of the head case  11  in the Z direction. In the present exemplary embodiment, a total of ten actuator units  13  corresponding to ten nozzle rows  37   a  formed in the nozzle plate  30  are provided so as to be arranged in the X direction and accommodated in the accommodation chambers  20  provided separately. Note that the number of actuator units  13  is not limited to the number described as an example. 
     The plurality of introduction flow paths  17  that introduce the ink from the liquid supplying unit  10  to the flow path unit  9  are formed inside the head case  11  at positions deviated from the accommodation chambers  20 . The introduction flow paths  17  penetrate through the head case  11  in the height direction, or in the Z direction, of the head case  11 . Furthermore, a plurality of cylindrical pipes serving as upper end portions of the introduction flow paths  17  are formed so as to protrude in the +Z direction in the surface of the head case  11  on the side on which the liquid supplying unit  10  and the electric substrate  14  are mounted. Among the plurality of pipes, the pipes positioned at both sides of the electric substrate  14  in the longitudinal direction or in the X direction, which is a direction in which the nozzle rows  37   a  described later are arranged, are positioning pipes  21 , and the pipes formed in an area between the positioning pipes  21  are third pipes  22 . The pipes  21  and  22  connect the introduction flow paths  17  formed in the head case  11  and the internal flow paths of the liquid supplying unit  10  in a liquid-tight manner. Details of the positioning pipes  21  and the third pipes  22  will be described later. 
     As illustrated in  FIG. 4 , the actuator units  13  described above include piezoelectric elements  25  functioning as drive elements (may also be referred to as pressure generating elements or actuators), fixing plates  26  to which the piezoelectric elements  25  are joined, and wiring members  27  that supply drive signals to the piezoelectric elements  25 . Note that the piezoelectric element  25  according to the present exemplary embodiment is a piezoelectric element of a so-called longitudinal vibration mode which is displaced in a direction intersecting the electric field direction. When a drive signal is supplied, the piezoelectric element  25  is displaced, in other words, stretched, in a direction intersecting the direction in which the piezoelectric material and the electrode are layered. A distal end portion of the piezoelectric element  25  is joined to an island portion  41  of the flow path unit  9 . 
     The flow path unit  9  is configured so that the nozzle plate  30  is joined to a surface of a flow path substrate  29  on a first side in the Z direction (on a −Z direction side) and so that a vibrating plate  31  is joined to a surface of the flow path substrate  29  on a second side in the Z direction (on a +Z direction side). A common liquid chamber  33 , an individual supply path  34 , a pressure chamber  35 , a nozzle communication hole  36 , and the nozzle  37  are provided in the flow path unit  9 . In the present exemplary embodiment, the nozzles  37  are formed in the nozzle plate  30 , and the common liquid chambers  33 , the individual supply paths  34 , the pressure chambers  35 , and the nozzle communication holes  36  are formed in the flow path substrate  29 . Note that the flow path substrate  29  may be configured of a plurality of layered substrates. 
     The nozzle plate  30  described above is a plate material in which the plurality of nozzles  37  are formed at predetermined pitches in the Y direction, and is fabricated of a metal plate such as, for example, a single crystal substrate or stainless steel. A plurality of nozzle rows  37   a  (nozzle groups) each configured of a plurality of nozzles  37  arranged in the Y direction are provided in the nozzle plate  30 . In the present exemplary embodiment, a total of 10 nozzle rows  37   a  are arranged in the nozzle plate  30  in the X direction. 
     The flow path substrate  29  is a plate material fabricated of a single crystal substrate, for example. The plurality of pressure chambers  35  arranged in the Y direction are formed in the flow path substrate  29  so as to correspond to the nozzles  37  described above. In the flow path substrate  29 , the common liquid chamber  33  is formed in an area deviated towards the outside in the X direction with respect to the areas where the pressure chambers  35  are formed. The common liquid chamber  33  and the pressure chambers  35  communicate with each other through the individual supply paths  34  provided in the pressure chambers  35 . The common liquid chamber  33  is a liquid chamber commonly provided for the pressure chambers  35  and stores the ink supplied through the introduction flow paths  17  of the head case  11 . A sectional area of the flow path of the individual supply path  34  is smaller than a sectional area of the pressure chamber  35 . The nozzle communication hole  36  that penetrates in the thickness direction, or the Z direction, of the flow path substrate  29  is formed on a side of the pressure chamber  35  opposite the individual supply path  34  side. Each nozzle communication hole  36  is a flow path that communicates the pressure chamber  35  and the corresponding nozzle  37  of the nozzle plate  30  to each other in a one-to-one manner. Note that the pressure chambers  35 , the individual supply paths  34 , and nozzle communication holes  36  in the flow path substrate  29  are formed by anisotropic etching. 
     The vibrating plate  31  described above has a double structure in which a support plate  38  and an elastic film  39  are layered. In the present exemplary embodiment, the support plate  38  is, for example, a stainless steel plate that is a type of metal plate. The vibrating plate  31  is configured of a composite plate in which a resin film, serving as the elastic film  39 , is laminated on a surface of the support plate  38 . Diaphragms  40  that change the volumes of the pressure chambers  35  are provided in the vibrating plate  31 . The diaphragms  40  are fabricated by partially removing the support plate  38  by etching or the like. In other words, the diaphragms  40  are formed by, while the portions of the support plate  38  to which the front end surfaces of the piezoelectric elements  25  are joined are left as the island portions  41 , removing, in a circular shape, the support plate  38  around the island portions  41  and having the elastic film  39  alone remain. Furthermore, since the front end surfaces of the piezoelectric elements  25  are joined to the island portions  41 , when the piezoelectric elements  25  become stretched, the diaphragms  40  become displaced accordingly and, due to the above, the volumes of the pressure chambers  35  fluctuate. In accordance with the fluctuation in volume, pressure fluctuation (in other words, pressure change) occurs in the ink inside the pressure chamber  35 . 
     Furthermore, in the liquid ejecting head  3  configured in the above manner, while in a state in which the flow paths from the common liquid chamber  33  through the pressure chambers  35  to the nozzles  37  are filled with ink, by driving the piezoelectric elements  25  in accordance with the drive signals that are applied through the wiring members  27  from the electric substrate  14  described later, a pressure fluctuation occurs in the ink inside each pressure chamber  35 , and due to the pressure oscillation, the ink is ejected from the corresponding predetermined nozzle  37 . Note that while in the present exemplary embodiment, a configuration including a so-called longitudinally vibrating piezoelectric elements  25  as the actuator units  13  has been described as an example; however, a configuration including a so-called flexural oscillation type piezoelectric elements can be adopted as well. The drive elements are not limited to the piezoelectric elements and, other than the above, drive elements such as electrostatic actuators or heating elements that are configured to eject a liquid such as ink from the nozzles  37  can be adopted as well. 
     The electric substrate  14  according to the present exemplary embodiment is a printed substrate (in other words, a rigid substrate) long in the X direction orthogonal to the Y direction, which is a nozzle row direction. In other words, the electric substrate  14  is long in the X direction in which the plurality of nozzle rows  37   a  are arranged. As illustrated in  FIGS. 2 and 3 , the electric substrate  14  includes, at both sides thereof in the X direction, connectors  43  to which flexible flat cables (FFC)  8  are connected from a printer main body side, and mounted components  44  such as IC chips, resistors, and the like on the upper surface thereof. Furthermore, wiring openings  45  into which the wiring members  27  coupled to the piezoelectric elements  25  are inserted are formed in the electric substrate  14  so as to penetrate the electric substrate  14  in a substrate thickness direction (in other words, the Z direction). In plan view in the Z direction, each wiring opening  45  has an opening shape that is longer in the Y direction than the width of the wiring member  27 . Two wiring members  27  are inserted through a single wiring opening  45 . In the electric substrate  14  according to the present exemplary embodiment, a total of five wiring openings  45  are formed so as to be arranged in the X direction. Substrate terminal portions (not shown) are formed in edge portions on both sides of each wiring opening  45  in the X direction, and wiring terminal portions of the corresponding wiring member  27  that have been inserted through the corresponding wiring opening  45  from the lower surface side of the electric substrate  14  are electrically joined to the substrate terminal portions. The electric substrate  14  has a wiring function that sends electric signals, such as a drive signal, sent from the printer main body side through the FFC  8  to the wiring members  27 . Furthermore, by transmitting the electric signal sent through the electric substrate  14  to the actuator units  13 , voltage is applied to the piezoelectric elements  25 . Switching elements (not shown), such as transmission gates, that switches between supplying and not supplying the electric signals to the piezoelectric elements  25  are provided in the wiring members  27  of the exemplary embodiment. Note that a configuration in which the switching elements are provided in the electric substrate  14  as the mounted components  44  may be adopted as well. 
     Furthermore, a plurality of through holes  46  and  47  that penetrate the electric substrate  14  in the substrate thickness direction (in other words, the Z direction) are formed at the positions corresponding to the pipes  21  and  22 . As illustrated in  FIG. 2 , in the present exemplary embodiment, two through holes  46  are formed so as to be arranged in the Y direction at areas between adjacent wiring openings  45 . The positioning through holes  47  that are, as described later, through holes also functioning as positioning holes are formed on both end sides of the electric substrate  14  in the X direction, which is a longitudinal direction, specifically, on the outside of the wiring openings  45  that are positioned at both ends in the X direction among the plurality of wiring openings  45  or on the connector  43  sides. Among the above positioning through holes  47 , an opening shape of a first positioning through hole  47   a  on a first end side (the left side in  FIG. 2  or on the +Z direction side) and an opening shape of a second positioning through hole  47   b  on a second end side (the right side in  FIG. 2  or on the −Z direction side) are, as described later, different. Note that first positioning through hole  47   a  according to the present exemplary embodiment is an example of a “first through hole”, and the second positioning through hole  47   b  is an example of a “second through hole”. A further detailed description of the configurations of the pipes  21  and  22  and the through holes  46  and  47  are given below. 
       FIG. 5  is a plan view illustrating a configuration of the electric substrate  14  near the through hole  46  and the third pipe  22 , and  FIG. 6  is a cross-sectional view taken along line VI-VI in  FIG. 5 . Furthermore,  FIG. 7  is a plan view illustrating a configuration of the electric substrate  14  near the first positioning through hole  47   a  and a first pipe  21   a , and  FIG. 8  is a cross-sectional view taken along line VIII-VIII in  FIG. 7 . Moreover,  FIG. 9  is a plan view illustrating a configuration of the electric substrate  14  near the second positioning through hole  47   b  and a second pipe  21   b , and  FIG. 10  is a cross-sectional view taken along line X-X and  FIG. 9 . Note that in the present exemplary embodiment, the first pipe  21   a  on the first end side in the X direction and the second pipe  21   b  on the second end side have the same shape, and when describing a configuration that is common to the above two pipes, each of the two pipes are merely referred to as a positioning pipe  21 . 
     As illustrated in  FIG. 6 , the third pipe  22  according to the present exemplary embodiment is a cylindrical member protruding towards the upper side in the Z direction (in other words, towards the liquid supplying unit  10  side) from a pipe formation surface  51  that is a surface lowered a notch towards an under surface side on which the flow path unit  9  is joined with respect to an upper surface (hereinafter, a layered surface) of the head case  11  on which the electric substrate  14  is layered. The pipe formation surface  51  faces the electric substrate  14 . A peripheral portion of a distal end surface (in other words, a top face) of the third pipe  22  of the present exemplary embodiment is rounded so as to have a tapered shape. With the above, when the liquid supplying unit  10  and the electric substrate  14  are attached to the head case  11 , the third pipes  22  can be inserted through the internal flow paths of the liquid supplying unit  10  in a smooth manner. A protrusion length of the third pipe  22  from the pipe formation surface  51  is set longer than a thickness of the electric substrate  14  and, in a state in which the third pipe  22  is inserted through the through hole  46  and the electric substrate  14  is layered on the layered surface of the head case  11 , a distal end portion of the third pipe  22  protrudes towards the liquid supplying unit  10  side from an upper surface of the electric substrate  14 . Note that the pipes  21  and  22  according to the present exemplary embodiment are illustrated, as an example, so as to protrude from the pipe formation surface  51  towards the +Z direction side; however, not limited to the above, a configuration in which the pipes  21  and  22  protrude in the +Z direction from the layered surface on which the electric substrate  14  is layered can be adopted. In brief, it is only sufficient that the pipes  21  and  22  protrude from a surface on the side on which the electric substrate  14  is layered. Note that the through hole  46  according to the present exemplary embodiment is an example of a “third through hole”. 
     As illustrated in  FIG. 5 , in the present exemplary embodiment, an external shape of the third pipe  22  in plan view in the +Z direction is an elliptic shape (in other words, a track shaped) long in the Y direction. An opening shape of the through hole  46  through which the third pipe  22  is inserted is set larger than an external shape of the third pipe  22 . In other words, the through hole  46  has an elliptic shape long in the Y direction corresponding to the planar shape of the third pipe  22 , and the dimension of the external shape of the through hole  46  is set larger than the dimension of the external shape of the third pipe  22 . In other words, the dimension of the through hole  46  in the Y direction and the dimension thereof in the X direction are set larger than the dimension of the third pipe  22  in the Y direction and the dimension thereof in the X direction, respectively. Accordingly, in a state in which the electric substrate  14  is positioned with the positioning pipes  21  and the positioning through holes  47  and is layered on the head case  11 , there is a gap between an external circumferential surface of the third pipe  22  and an internal circumferential surface of the through hole  46 , and the third pipe  22  and the through hole  46  do not come in contact with each other. In other words, the third pipe  22  is inserted into the through hole  46  while non-contacting the through hole  46 . 
     As illustrated in  FIGS. 7 and 9 , the first pipe  21   a  and the second pipe  21   b  serving as the positioning pipes  21  according to the present exemplary embodiment are, similar to the third pipes  22 , cylindrical members protruding towards the upper side in the Z direction (the +Z direction) from the pipe formation surface  51 . Furthermore, similar to the third pipes  22 , the distal end surfaces of the positioning pipes  21  are rounded so as to have tapered shapes and, the entire protrusion length of each positioning pipe  21  from the pipe formation surface  51  is matched with the protrusion length of each third pipe  22 . Accordingly, in a state in which the positioning pipes  21  are inserted through the positioning through holes  47  and the electric substrate  14  is layered on the layered surface of the head case  11 , distal end portions of the positioning pipes  21  protrude towards the liquid supplying unit  10  side with respect to the upper surface of the electric substrate  14 . 
     As illustrated in  FIGS. 7 to 10 , the positioning pipe  21  according to the present exemplary embodiment is different from the third pipe  22  in that the positioning pipe  21  includes a coupling portion  48  that is coupled to the internal flow path of the liquid supplying unit  10 , and a positioning portion  49  formed on a base end side (in other words, on the pipe formation surface  51  side) with respect to the coupling portion  48 . In plan view, the coupling portion  48  is formed with a shape and a size that are similar to those of the third pipe  22 . In other words, the external shape of the third pipe  22  in plan view is an elliptic shape and, in the present exemplary embodiment, is an elliptic shape long in the Y direction. On the other hand, the positioning portion  49  has, in plan view, a shape that is similar to the shape of the coupling portion  48 , and a dimension of an external shape of the positioning portion  49  is set larger than a dimension of an external shape of the coupling portion  48 . In other words, the positioning portion  49  has an elliptic shape corresponding to the planar shape of the coupling portion  48 . Furthermore, a dimension of the positioning portion  49  in the Y direction and a dimension thereof in the X direction are set larger than a dimension of the coupling portion  48  in the Y direction and a dimension thereof in the X direction, respectively. In other words, the positioning portion  49  is a portion where the external shape thereof has been increased compared with that of the coupling portion  48 , and a thickness of the positioning portion  49  in a direction parallel to the XY plane is larger than that of the coupling portion  48 . Hereinafter, the description will be given assuming that the shape and the dimension of the positioning pipe  21  in plan view are the shape and the dimension of the positioning portion  49  in plan view. 
     The top face of the positioning portion  49  in the Z direction (a surface on the +Z direction side) is set to be flush with the upper surface of the electric substrate  14  layered on the layered surface or is above (in other words, is on the distal end side of the coupling portion  48 ) the upper surface of the electric substrate  14 . The external circumferential surface of such a positioning portion  49  defines the relative position between the head case  11  and the electric substrate  14  by contacting the internal circumferential surface of the positioning through hole  47 , and functions as a contact surface of the present disclosure. In other words, in addition to functioning as flow paths forming the introduction flow paths  17 , the positioning pipes  21  additionally functions as a positioning pin that defines the relative position between the head case  11  and the electric substrate  14 . Furthermore, the positioning through hole  47  functioning as a through hole through which the positioning pipe  21  is passed additionally functions as a positioning hole that defines the relative position between the head case  11  and the electric substrate  14 . Furthermore, by additionally providing the positioning portion  49  that is thicker than the coupling portion  48 , the external circumferential surface of the positioning portion  49  can be formed as a contact surface having a higher accuracy and more flatness compared with the coupling portion  48  including a tapered shape at the distal end portion thereof, and the positioning accuracy can be increased. 
     As illustrated in  FIG. 3 , the positioning pipes  21  according to the present exemplary embodiment are disposed outside the nozzle rows  37   a  disposed at both ends in the X direction among the plurality of nozzle rows  37   a . In other words, among the plurality of pipes provided in the head case  11 , the first pipe  21   a  disposed on the first end side in the X direction (on the left side in  FIG. 2  in the present exemplary embodiment or on the +X direction side) and the second pipe  21   b  disposed on the second end side in the X direction (on the right side in  FIG. 2  or on the −X direction side) are two pipes, among the plurality of pipes, that are disposed farthest away from each other. By adopting such a configuration, a longer distance between the first pipe  21   a  and the second pipe  21   b  (in other words, the distance between the center of the first pipe  21   a  and the center of the second pipe  21   b ) related to positioning of the head case  11  and the electric substrate  14  can be obtained and, accordingly, the positioning accuracy is improved further. Furthermore, the first pipe  21   a  and the second pipe  21   b  are disposed so that an imaginary straight line connecting the first pipe  21   a  and the second pipe  21   b  extends in the X direction. As illustrated in  FIG. 7 , the external shape of the first positioning through hole  47   a , among the positioning through holes  47   a  and  47   b  through which the positioning pipes  21  are inserted, on the first end side in plan view is set larger than the external shape of the coupling portion  48  and is set about the same or slightly larger than the external shape of the positioning portion  49 . In other words, the first positioning through hole  47   a  has an elliptic shape corresponding to the planar shape of the positioning portion  49  of the positioning pipe  21  and, furthermore, the dimension of the first positioning through hole  47   a  in the Y direction and the dimension thereof in the X direction as set about the same or slightly larger than the dimension of the positioning portion  49  in the Y direction and the dimension thereof in the X direction. In brief, the first positioning through hole  47   a  is a through hole in which the opening dimension thereof is, within a range allowing the positioning portion  49  to be inserted therethrough, set so that a gap between the first positioning through hole  47   a  and the external circumferential surface of the positioning portion  49  is small. Accordingly, in a case in which the electric substrate  14  is mounted on a mounting surface of the head case  11 , when the first pipe  21   a  is inserted into the first positioning through hole  47   a , at least a portion of the external circumferential surface of the positioning portion  49  of the first pipe  21   a  comes in contact with the internal circumferential surface of the first positioning through hole  47   a.    
     As illustrated in  FIGS. 9 and 10 , in the second positioning through hole  47   b  on the second end side, among the positioning through holes  47   a  and  47   b  through which the positioning pipes  21  are inserted, while the dimension in the Y direction is set so as to match the dimension of the first positioning through hole  47   a , the dimension in the X direction that is a direction in which the second positioning through hole  47   b  and the first positioning through hole  47   a  are arranged is set larger than the dimension of the first positioning through hole  47   a  in the X direction. Accordingly, in a case in which the electric substrate  14  is mounted on the mounting surface of the head case  11 , when the second pipe  21   b  is inserted through the second positioning through hole  47   b , a gap G is formed in the X direction between the external circumferential surface of the positioning portion  49  of the second pipe  21   b  and the internal circumferential surface of the second positioning through hole  47   b , which allows the head case  11  and the electric substrate  14  to be positioned while absorbing, within the range of the gap G, an error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b.    
     When manufacturing the liquid ejecting head  3  and when the electric substrate  14  is layered on the layered surface of the head case  11 , the third pipes  22  of the head case  11  is inserted through the through holes  46  of the electric substrate  14  while non-contacting the through holes  46  and, furthermore, the positioning pipes  21  at both sides in the X direction are inserted into the positioning through holes  47   a  and  47   b  so that the internal circumferential surfaces of the positioning through holes  47   a  and  47   b  are in contact with the external circumferential surfaces of the positioning portions  49  of the positioning pipes  21 ; accordingly, the position of the electric substrate  14  with respect to the head case  11  is set. 
     As described above, since the configuration of the present disclosure, the plurality of pipes in which the introduction flow paths  17  are formed includes positioning pipes  21  that include the contact surfaces (the external circumferential surfaces of the positioning portions  49  in the present exemplary embodiment) that come in contact with the internal circumferential surfaces of the positioning through holes  47 , the positioning pipes  21  function as positioning pins that position the head case  11  and the electric substrate  14 , and the positioning through holes  47  through which the positioning pipes  21  are inserted function as positioning holes that position the head case  11  and the electric substrate  14 . Accordingly, other than the pipes  21  and  22  and the through holes  46  and  47  into which the pipes  21  and  22  are inserted, projections (in other words, positioning pins) that determine the position of the head case  11  and the electric substrate  14  and positioning holes through which the projections are inserted do not need to be separately provided. Accordingly, more space, amounting to the space saved with the above, for disposing the wiring and the mounted components  44  can be obtained on the electric substrate  14  and a reduction in the size of the electric substrate  14  can be achieved. As a result, a contribution to size reduction of the liquid ejecting head  3  can be made. Furthermore, since known positioning projections are not needed, shortcomings such as a decrease in liquid tightness of the flow paths between the members caused by such projections coming in contact with the other members (the liquid supplying unit  10  in the present exemplary embodiment, for example) when manufacturing the liquid ejecting head can be suppressed from occurring. 
     Note that while positioning of the head case  11  and the electric substrate  14  can be performed with at least one set of the positioning pipe  21  of the head case  11  and the positioning through hole  47  of the electric substrate  14 , by providing two or more sets of the positioning pipe  21  and the positioning through hole  47  and performing positioning at a plurality of portions, the positioning accuracy can be improved furthermore. Furthermore, in the present exemplary embodiment, the pipes, namely, the first pipe  21   a  and the second pipe  21   b , are disposed at both end sides of the electric substrate  14  in the X direction, and the distance between the first pipe  21   a  and the second pipe  21   b  disposed at both end sides (in other words, the distance between the center of the first pipe  21   a  and the center of the second pipe  21   b  in the Z direction in plan view) is longer than a dimension of the electric substrate  14  in a short direction (in the Y direction in the present exemplary embodiment). Furthermore, while in the present exemplary embodiment, a configuration in which the pipes  21  and  22  are provided integrally with the head case  11  has been described as an example, a configuration in which the pipes  21  and  22  provided as members separate to the head case  11  are attached to the head case  11  may be adopted as well. Furthermore, in the exemplary embodiment described above, while a configuration in which the positioning portions  49  are formed in the positioning pipes  21  and in which the external circumferential surfaces of the positioning portions  49  function as the contact surfaces has been described as an example, the present disclosure is not limited to such a configuration. For example, a configuration in which portions corresponding to the positioning portion  49  are not provided in the positioning pipes  21 , in other words, a configuration in which the positioning pipes  21  and the third pipes  22  have a common shape and in which the external circumferential surfaces of the positioning pipes  21  themselves function as the contact surfaces may be adopted as well. Furthermore, a configuration in which positioning portions  49  that are members separate from the positioning pipes  21  are attached to external circumferences of the positioning pipes  21  can be adopted as well. In such a case, the positioning portions  49  can be configured of a material, such as metal, different from that of the positioning pipes  21 . As described above, in a configuration in which the positioning portions  49  are separate members, by forming the contact surfaces of the positioning portions  49  more accurately, the positioning accuracy can be improved furthermore. 
       FIGS. 11 and 12  are diagrams illustrating a first modification of the positioning pipe  21  and the positioning through hole  47 .  FIG. 11  is a plan view illustrating a configuration of the first pipe  21   a  and the first positioning through hole  47   a  according to the first modification.  FIG. 12  is a plan view illustrating a configuration of the second pipe  21   b  and the second positioning through hole  47   b  according to the first modification. In the first exemplary embodiment, a configuration in which the external shapes of the two third pipes  22  in plan view are each an elliptic shape has been described as an example; however, not limited to such a configuration, the third pipes  22  can adopt various shapes. 
     For example, as illustrated in  FIGS. 11 and 12 , the external shapes of the first pipe  21   a  and the second pipe  21   b  serving as positioning pipes  21  according to the first modification, in other words, the planar shapes of the coupling portion  48  and the positioning portion  49  are both a perfect circle. Furthermore, the shape of the first positioning through hole  47   a  through which the first pipe  21   a  on the first end side is inserted is a perfect circle in plan view. The size of the first positioning through hole  47   a  is set so that the gap between the first positioning through hole  47   a  and the external circumferential surface of the positioning portion  49  is small within the range allowing the positioning portion  49  to be inserted through the first positioning through hole  47   a . Accordingly, in a case in which the electric substrate  14  is mounted on the mounting surface of the head case  11 , when the first pipe  21   a  is inserted into the first positioning through hole  47   a , at least a portion of the external circumferential surface of the positioning portion  49  comes in contact with the internal circumferential surface of the first positioning through hole  47   a . Here, the term “perfect circle” means not only a perfect circle but also a somewhat incomplete one. In brief, a perfect circle includes a circle that can generally be visually recognized as a substantially perfect circle in plan view. 
     As illustrated in  FIG. 12 , while a dimension of the second positioning through hole  47   b , through which the second pipe  21   b  on the second end side is inserted, in the Y direction is set to match the dimension of the first positioning through hole  47   a , a dimension in the X direction, which is a direction in which the second positioning through hole  47   b  and the first positioning through hole  47   a  are arranged, is set larger than the dimension of the first positioning through hole  47   a  in the X direction. In other words, in plan view, the second positioning through hole  47   b  has an elliptic shape long in the X direction. Furthermore, in a case in which the electric substrate  14  is mounted on the mounting surface of the head case  11 , when the second pipe  21   b  is inserted through the second positioning through hole  47   b , a gap G is formed in the X direction between the external circumferential surface of the positioning portion  49  of the second pipe  21   b  and the internal circumferential surface of the second positioning through hole  47   b , which allows the head case  11  and the electric substrate  14  to be positioned while absorbing, within the range of the gap G, an error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b.    
       FIG. 13  is a plan view illustrating a configuration of the second pipe  21   b  and the second positioning through hole  47   b  according to a second modification. In the present modification, while the configurations of the first pipe  21   a  on the first end side, among the two positioning pipes  21 , and the first positioning through hole  47   a  through which the first pipe  21   a  is inserted are common with those of the first modification, the configurations of the second pipe  21   b  on the second end side and the second positioning through hole  47   b  through which the second pipe  21   b  is inserted are different from those of the first modification. In the present modification, the shape of the second positioning through hole  47   b  in plan view is a perfect circle similar to that of the first positioning through hole  47   a . Furthermore, regarding the second pipe  21   b  on the second end side inserted through the second positioning through hole  47   b , while a dimension in the Y direction when in plan view is set to match the diameter of the first pipe  21   a  on the first end side, a dimension in the X direction is set smaller than the diameter of the first pipe  21   a  on the first end side and an inner diameter of the second positioning through hole  47   b . In other words, an external shape of the second pipe  21   b  according to the present modification in plan view is an elliptic shape long in the Y direction and short in the X direction. Accordingly, in a case in which the electric substrate  14  is mounted on the mounting surface of the head case  11 , when the second pipe  21   b  is inserted through the second positioning through hole  47   b , since a gap G is formed in the X direction between the external circumferential surface of the positioning portion  49  of the second pipe  21   b  and the internal circumferential surface of the second positioning through hole  47   b , the head case  11  and the electric substrate  14  can be positioned while the gap G absorbs an error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b.    
       FIG. 14  is a plan view illustrating a configuration of the first pipe  21   a  and the second pipe  21   b  serving as the positioning pipes  21  according to a third modification. A feature of the positioning pipe  21  according to the present modification is that the positioning pipe  21  includes rib-shaped positioning portions  49  that are disposed along the external circumference of the coupling portion  48  at constant intervals. The positioning portion  49  is, in plan view, a portion protruding in a trapezoidal or triangular manner in a radial direction of the coupling portion  48  from the external circumferential surface of the coupling portion  48 . A plurality of (eight in the present modification) positioning portions  49  are provided along the external circumference of the coupling portion  48 . It goes without saying that such shapes of the rib-shaped positioning portion  49  in plan view and the number provided along the coupling portion  48  are not limited to those described as examples and various configurations can be adopted. Note that the positioning through holes  47   a  and  47   b  and other configurations are similar to those of the first modification described above. According to the present modification, since the contact areas between the external circumferential surfaces of the positioning pipe  21 , in other words, the external circumferential surfaces of the positioning portions  49  functioning as the contact surfaces (in other words, ends of the positioning portions  49  protruding from the coupling portion  48 ) and the internal circumferential surfaces of the positioning through holes  47   a  and  47   b  are small, even when the gaps between the internal circumferential surface of the first positioning through hole  47   a  and the external circumferential surfaces of the positioning portions  49  are set smaller and the gaps with the second positioning through hole  47   b  in the Y direction are set smaller, the positioning portions  49  of the first and second pipes  21   a  and  21   b  can be inserted through the positioning through holes  47   a  and  47   b . Accordingly, the external circumferential surfaces of the positioning portions  49  in the first and second pipes  21   a  and  21   b  and the internal circumferential surfaces of the positioning through holes  47  can be in contact with each other in a more reliable manner and the positioning accuracy can be improved further. 
       FIGS. 15 and 16  are plan views illustrating configurations of the positioning through holes  47   a  and  47   b  according to a fourth modification. The first positioning through hole  47   a  according to the present modification has a recessed/protruded shape formed along the internal circumferential surface. The protruded portions provided in the internal circumferential surface of the first positioning through hole  47   a  are portions protruded in a trapezoidal or triangular manner from the internal circumferential surface towards the center. Furthermore, the second positioning through hole  47   b  has a shape in which the shape of the first positioning through hole  47   a  has been enlarged in the X direction. Note that the shapes and the numbers of the protruded portions of the positioning through holes  47   a  and  47   b  are not limited to those described as an example. The number of protrusions/recesses in the first positioning through hole  47   a  and the number of protrusions/recesses in the second positioning through hole  47   b  may be different and various configurations can be adopted. Note that the first and second pipes  21   a  and  21   b  and other configurations are similar to those of the first modification described above. According to the fourth modification, since the contact areas between the external circumferential surfaces of the first pipe  21   a  and the second pipe  21   b , in other words, the external circumferential surfaces of the positioning portions  49  functioning as the contact surfaces and the internal circumferential surfaces of the positioning through holes  47   a  and  47   b  (in other words, the end surfaces of the protruded portions on the positioning pipe  21  side) are small, even when the gaps between the internal circumferential surface of the first positioning through hole  47   a  and the external circumferential surfaces of the positioning portions  49  are set smaller and the gaps with the second positioning through hole  47   b  in the Y direction are set smaller, the positioning portions  49  of the first and second pipes  21   a  and  21   b  can be inserted through the positioning through holes  47   a  and  47   b . Accordingly, the external circumferential surfaces of the positioning portions  49  in the first and second pipes  21   a  and  21   b  and the internal circumferential surfaces of the positioning through holes  47   a  and  47   b  can be in contact with each other in a more reliable manner and the positioning accuracy can be improved further. Other than the above, the shapes of the positioning pipes  21  and the positioning through holes  47  in plan view (in other words, the external shapes) are not limited to the shapes described above as examples and various shapes such as a polygonal shape can be adopted. In brief, any configuration configured to position the head case  11  and the electric substrate  14  by having the contact surfaces of the positioning pipes  21  and the internal circumferential surfaces of the positioning through holes  47  contact each other is sufficient. 
       FIG. 17  is a plan view of the liquid ejecting head  3  according to a second exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  is omitted. In the first exemplary embodiment described above, a configuration has been described as an example in which the direction in which the set of first pipe  21   a  and the first positioning through hole  47   a  and the set of the second pipe  21   b  and the second positioning through hole  47   b  are arranged is the X direction, in other words, a direction parallel to the longitudinal direction of the electric substrate  14 ; however, the configuration is not limited to the above. While the present exemplary embodiment is similar to the first exemplary embodiment in that the set of the first pipe  21   a  and the first positioning through hole  47   a  and the set of the second pipe  21   b  and the second positioning through hole  47   b  are disposed on both end sides of the electric substrate  14  in the X direction, the direction in which the sets are arranged is an Xa direction which is inclined against the X direction. In other words, the set of the first pipe  21   a  and the first positioning through hole  47   a  are disposed on a first side (the upper side in  FIG. 17  with respect to an imaginary center line Lb) in the Y direction and the set of the second pipe  21   b  and the second positioning through hole  47   b  are disposed on a second side (the lower side in  FIG. 17  with respect to the imaginary center line Lb) in the Y direction, so as to be point symmetric to each other about an imaginary center Cb of the electric substrate  14 . With the above, since a longer distance between the sets (in other words, the distance between the center of the first pipe  21   a  and the center of the second pipe  21   b ) can be obtained, the positioning accuracy is improved further. 
     Regarding the set of the second pipe  21   b  and the second positioning through hole  47   b  in the present exemplary embodiment, the second pipe  21   b  is formed so that a direction of a major axis of the second pipe  21   b  having an elliptic shape extends in a Ya direction, and a direction of a minor axis thereof extends in the Xa direction, in other words, the second pipe  21   b  is formed so that the major axis and the minor axis are inclined from the Y direction and the X direction, respectively. Accordingly, regarding the planar shape of the second positioning through hole  47   b , a dimension in the Ya direction is set to match the dimension of the first positioning through hole  47   a  in the Y direction, while the dimension in the Xa direction that is a direction in which the set of the second pipe  21   b  and the second positioning through hole  47   b  and the set of the first pipe  21   a  and the first positioning through hole  47   a  are arranged is set larger than the dimension of the first positioning through hole  47   a  in the X direction. With the above, the gap G formed between the external circumferential surface of the positioning portion  49  of the second pipe  21   b  and the internal circumferential surface of the second positioning through hole  47   b  becomes larger in the Xa direction, which is the direction in which the set of the first pipe  21   a  and the first positioning through hole  47   a  and the set of the second pipe  21   b  and the second positioning through hole  47   b  are arranged, than in the Ya direction orthogonal to the Xa direction. Accordingly, positioning of the head case  11  and the electric substrate  14  can be performed while absorbing the error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b . Note that there may be no gap G in the Ya direction. Note that other configurations are similar to those of the first exemplary embodiment. 
       FIG. 18  is a plan view of the liquid ejecting head  3  according to a third exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  is omitted. Note that the description will be given while in  FIG. 18 , the lower side in the Y direction (the +Y direction side) is referred to as the first side, and the upper side in the Y direction (the −Y direction side) is referred to as the second side (the same applies to  FIG. 19 ). Features of the present exemplary embodiment are that walls  52   a  and  52   b  are formed at both sides of an area in the Y direction so as to surround the area, the area being an area in the mount surface of the head case  11  where the electric substrate  14  is mounted, and that urging members  53  that urge the electric substrate  14  towards the first side in a W direction, which is a fourth direction, are provided between the wall  52   a  on the second side and the electric substrate  14 . In the example in  FIG. 18 , the W direction matches the Y direction or the second direction, and the urging members  53  urge the electric substrate  14  towards the first side in the W direction or the Y direction. With the above, the surfaces of the internal circumferential surfaces of the positioning through holes  47   a  and  47   b  on the second side in the W direction, in other words, the surfaces on the upper side of the drawing, and the surfaces of the positioning portions  49  of the first pipe  21   a  and the second pipe  21   b  on the second side in the W direction become reliably in contact with each other, and the positioning of the head case  11  and the electric substrate  14  are performed with a higher accuracy. 
     Note that the W direction that is the direction in which the urging members  53  urge the electric substrate  14  to one of the sides can be any direction, and may be a direction parallel to the X direction or may be a direction inclined from the X direction and the Y direction. For example, an elastic material such as rubber or elastomer, or a biasing member such as a spring can be adopted as the urging member  53 . Furthermore, an eccentric cam, for example, can be adopted as the urging member  53 . In such a case, while an external circumference of the eccentric cam is in contact with the electric substrate  14 , the electric substrate  14  can be urged to one of the sides by the increase and decrease in the cam diameter from the rotation center of the eccentric cam to the portion in contact with the electric substrate  14  when the eccentric cam is rotated. Furthermore, a configuration, for example, in which the electric substrate  14  is urged to one of the sides according to a screwing amount of an adjusting screw while the distal end portion thereof is in contact with the electric substrate  14 . Other configurations are similar to those of the first exemplary embodiment. 
       FIG. 19  is a plan view of the liquid ejecting head  3  according to a modification of the third exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  is omitted. In the present modification, only a single set of the positioning pipe  21  and the positioning through hole  47  are provided, and the other sets are sets of the third pipe  22  and the through hole  46 . Furthermore, in the wall  52   b  on the first side (the +Y direction side) among the walls  52   a  and  52   b  of the head case  11 , a protruded portion  54  protruded towards the electric substrate  14  on the mount surface is formed on a second end side that is a side in the X direction opposite the side on which the positioning pipe  21  and the positioning through hole  47  are provided (in other words, an opposite side with the imaginary center Cb of the electric substrate  14  in between). An end surface of the protruded portion  54  on the electric substrate  14  side functions as an abutting surface  55  that defines the position of the electric substrate  14 . In other words, in the present modification, the relative position between the head case  11  and the electric substrate  14  are defined by urging the electric substrate  14  towards the first side in the W direction (the Y direction in the modification in  FIG. 19 ) with the urging members  53 , by having the surface of the internal circumferential surface of the positioning through hole  47  on the second side in the fourth direction contact the surface of the positioning portion  49  of the positioning pipe  21  on the second side in the W direction, and by having a lateral surface of the electric substrate  14  on the first side in the W direction contact the abutting surface  55  of the protruded portion  54 . In such a configuration as well, the relative position between the head case  11  and the electric substrate  14  is defined highly accurately. Note that it is only sufficient that the abutting surface  55  is disposed on the opposite side in the longitudinal direction (the X direction in the present modification) of the electric substrate  14  with respect to the set of positioning pipe  21  and the positioning through hole  47  with the imaginary center Cb of the electric substrate  14  in between, and on the first side in the fourth direction, which is the direction in which the urging member  53  urges the electric substrate  14 . In such a case as well, the positioning accuracy improves when the distance between the set of the positioning pipe  21  and the positioning through hole  47 , and the abutting surface  55  is longer. Furthermore, it is desirable that the abutting surface  55  be a surface formed in a highly accurate manner by lapping and the like. It is more desirable since the positioning accuracy becomes improved as the area becomes smaller. Furthermore, the abutting surface  55  is not limited to a surface configured as a portion of the head case  11  and, for example, can be configured of a member different from the head case  11 . In such a case, the member including the abutting surface  55  can be configured of a material different from that of the head case  11  such as, for example, metal. Other configurations are similar to those of the third exemplary embodiment. 
       FIG. 20  is a plan view of the liquid ejecting head  3  according to a fourth exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  and the mounted components  44  and the like on the electric substrate  14  are omitted. The present exemplary embodiment is different from the exemplary embodiments described above in that the electric substrate  14  is long in the Y direction, which is the nozzle row direction. In the present exemplary embodiment, two nozzle rows  37   a , each provided in the Y direction, are arranged in the X direction, and a single set of positioning pipe  21  and the positioning through hole  47  are provided for each nozzle row  37   a . More specifically, a single set of positioning pipe  21  and positioning through hole  47  is provided on the first side (the upper side in  FIG. 20 ) and on the second side (the lower side in  FIG. 20 ) with respect to the center (the position corresponding to the imaginary center Cb of the electric substrate  14  in the present exemplary embodiment) of the nozzle rows  37   a  in the Y direction. The distance between the first pipe  21   a  and the second pipe  21   b  (in other words, the distance between the center of the first pipe  21   a  and the center of the second pipe  21   b  in the Z direction when in plan view), which are positioning pipes  21  disposed on both sides, is longer than the dimension of the electric substrate  14  in the short direction (the X direction in the present exemplary embodiment). In the present exemplary embodiment, a direction in which the sets of positioning pipe  21  and positioning through hole  47  are arranged is referred to as the Xa direction, and a direction orthogonal to the Xa direction is referred to as the Ya direction. 
     The positioning through hole  47  in the set, among the sets of positioning pipe  21  and the positioning through hole  47 , disposed on the first side is a first positioning through hole  47   a  in which the gap with the external circumferential surface of the positioning portion  49  is formed small within a range allowing the positioning portion  49  of the first pipe  21   a  to be inserted therethrough, and the positioning through hole  47  in the set disposed on the second side is the second positioning through hole  47   b  in which, while the dimension in the Ya direction is set to match the dimension of the first positioning through hole  47   a  in the X direction, the dimension in the Xa direction is set larger than the dimension of the first positioning through hole  47   a  in the Y direction. In accordance with the above, the second pipe  21   b  formed in an elliptic shape in plan view is formed so that the major axis direction extends in the Xa direction, and the minor axis direction extends in the Ya direction. With the above, the gap G in the Xa direction, which is the direction in which the set of the first pipe  21   a  and the first positioning through hole  47   a  and the set of the second pipe  21   b  and the second positioning through hole  47   b  are arranged, is larger than the gap G between the second pipe  21   b  and the second positioning through hole  47   b  in the Ya direction. With the above, positioning of the head case  11  and the electric substrate  14  can be performed while absorbing the error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b . Note that when the error between the distance between the positioning pipes  21  and the distance between the positioning through holes  47  is not an issue, the positioning through hole  47  on the second side can be the first positioning through hole  47   a.    
     As described above, in the present exemplary embodiment, since the set of the first pipe  21   a  and the positioning through hole  47   a  is disposed at a position corresponding to a first end portion of the nozzle row  37   a  arranged in the X direction on the first side (the left side in  FIG. 20 ), and the set of the second pipe  21   b  and the positioning through hole  47   b  is disposed at a position corresponding to a second end portion of the nozzle row  37   a  arranged in the X direction and on the second side (the right side in  FIG. 20 ), a longer distance can be obtained between the above sets. Furthermore, when the electric substrate  14  is layered on the layered surface of the head case  11 , the position of the electric substrate  14  with respect to the head case  11  is determined by inserting the first pipe  21   a  and the second pipe  21   b  on both sides in the Y direction through the positioning through holes  47   a  and  47   b , respectively, and by having the internal circumferential surface of each positioning through hole  47  come in contact with the external circumferential surface of the positioning portion  49  of the corresponding positioning pipe  21 . In the present exemplary embodiment as well, there is no need to, other than the positioning pipes  21  and the positioning through holes  47 , separately provide positioning pins and positioning holes that position the head case  11  and the electric substrate  14 . Accordingly, more space, amounting to the space saved with the above, for disposing the wiring and the mounted components  44  can be obtained on the electric substrate  14  and a reduction in the size of the electric substrate  14  can be achieved. As a result, a contribution to size reduction of the liquid ejecting head  3  can be made. Note that when the electric substrate  14  is long in the direction of the nozzle rows  37   a , the number of the nozzle rows  37   a  is not limited to two that has been illustrated as an example and can be one or three or more. In such a case, it is only sufficient that the sets of the positioning pipe  21  and the positioning through hole  47  through which the positioning pipe  21  is inserted are disposed, in the short direction of the electric substrate  14 , outside the area where the nozzle rows  37   a  are formed and on the first side and the second side of the nozzle rows  37   a  in the Y direction. 
       FIG. 21  is a plan view of the liquid ejecting head  3  according to a first modification of the fourth exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  and the mounted components  44  and the like on the electric substrate  14  are omitted. In the present modification, two sets of the third pipe  22  and the through hole  46  or two sets of the positioning pipe  21  and the positioning through hole  47  are provided for each of the nozzle row  37   a . More specifically, corresponding to the nozzle row  37   a  disposed on the first side (the left side in  FIG. 21 ) in the X direction, a set of the third pipe  22  and the through hole  46  are provided, with respect to the center of the nozzle row  37   a , on each of the first side (the upper side in  FIG. 21 ) and the second side (the lower side in  FIG. 21 ) in the Y direction. Furthermore, corresponding to the nozzle row  37   a  disposed on the second side (the right side in  FIG. 21 ) in the X direction, a set of the first pipe  21   a  and the first positioning through hole  47   a  is provided, with respect to the center of the nozzle row  37   a , on the first side in the Y direction and a set of the second pipe  21   b  and the second positioning through hole  47   b  is provided, with respect to the center of the nozzle row  37   a , on the second side. In the present modification as well, when the electric substrate  14  is layered on the layered surface of the head case  11 , the position of the electric substrate  14  with respect to the head case  11  is determined by inserting the first pipe  21   a  and the second pipe  21   b  on both sides in the Y direction through the positioning through holes  47   a  and  47   b , respectively, and by having the internal circumferential surface of the positioning through holes  47   a  and  47   b  come in contact with the external circumferential surface of the positioning portion  49  of the first pipe  21   a  and the second pipe  21   b , respectively. Note that in the present modification, a configuration in which, regarding the positional relationship between the set of the first pipe  21   a  and the first positioning through hole  47   a  and the set of the second pipe  21   b  and the second positioning through hole  47   b , the positions in the X direction are the same has been described as an example; however, not limited to the above and similar to the fourth exemplary embodiment, the positions in the X direction may be different. Furthermore, it is only sufficient that at least the set of the first pipe  21   a  and the first positioning through hole  47   a  is included, and the set of the second pipe  21   b  and the second positioning through hole  47   b  does not necessarily have to be included. In such a case, a configuration in which the third pipe  22  and the through hole  46  are provided at positions corresponding to the set of the second pipe  21   b  and the second positioning through hole  47   b  may be adopted. Other configurations are similar to those of the fourth exemplary embodiment. 
       FIG. 22  is a plan view of the liquid ejecting head  3  according to a second modification of the fourth exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  and the mounted components  44  and the like on the electric substrate  14  are omitted. In the present modification, three sets including the set of the third pipe  22  and the through hole  46  and the set of the positioning pipe  21  and the positioning through hole  47  are provided for each of the nozzle row  37   a . More specifically, corresponding to the nozzle row  37   a  disposed on the first side (the left side in  FIG. 22 ) in the X direction, three sets of the third pipe  22  and the through hole  46  are disposed with a space between each other. Furthermore, corresponding to the nozzle row  37   a  disposed on the second side (the right side in  FIG. 22 ) in the X direction, the set of the first pipe  21   a  and the first positioning through hole  47   a , the set of the third pipe  22  and the through hole  46 , and the set of the second pipe  21   b  and the second positioning through hole  47   b  are provided in that order from the first side towards the second side in the Y direction with a space between each other. Note that other configurations are similar to those of the fourth exemplary embodiment. 
       FIG. 23  is a plan view of the liquid ejecting head  3  according to a third modification of the fourth exemplary embodiment viewed in the +Z direction. Illustration of the liquid supplying unit  10  and the mounted components  44  and the like on the electric substrate  14  are omitted. In the present modification, three sets including the set of the third pipe  22  and the through hole  46  and the set of the positioning pipe  21  and the positioning through hole  47  are provided for each of the nozzle row  37   a . More specifically, corresponding to the nozzle row  37   a  disposed on the first side (the left side in  FIG. 23 ) in the X direction, the set of the first pipe  21   a  and the first positioning through hole  47   a  and two sets of the third pipe  22  and the through hole  46 , or a total of three sets, are provided with a space between each other. Furthermore, corresponding to the nozzle row  37   a  disposed on the second side (the right side in  FIG. 23 ) in the X direction, two sets of the third pipe  22  and the through hole  46 , and the set of the second pipe  21   b  and the second positioning through hole  47   b  are provided in that order from the first side towards the second side in the Y direction with a space between each other. Similar to the fourth exemplary embodiment, while the dimension of the second positioning through hole  47   b  according to the present modification in the Ya direction is set to match the dimension of the first positioning through hole  47   a  in the X direction, the dimension in the Xa direction is set larger than the first positioning through hole  47   a  in the Y direction. In accordance with the above, the second pipe  21   b  formed in an elliptic shape in plan view is formed so that the major axis direction extends in the Xa direction, and the minor axis direction extends in the Ya direction. With the above, positioning of the head case  11  and the electric substrate  14  can be performed while absorbing the error between the distance between the first pipe  21   a  and the second pipe  21   b  and the distance between the positioning through holes  47   a  and  47   b . Other configurations are similar to those of the fourth exemplary embodiment. According to the above configuration, compared with the second modification, a longer distance between the set of the positioning pipe  21  and the positioning through hole  47   a  and the set of the positioning pipe  21  and the positioning through hole  47   b  on the second side can be obtained; accordingly, the positioning accuracy is improved. Other configurations are similar to those of the fourth exemplary embodiment. 
     Note that in the exemplary embodiments described above, a configuration in which the positioning is performed with sets of positioning pipe  21  and the positioning through hole  47 , or a configuration in which positioning is performed with a set of positioning pipe  21  and the positioning through hole  47 , and the abutting surface  55  have been described as examples; however, not limited to the above configurations, a configuration in which the positioning of the head case  11  and the electric substrate  14  is performed using the set of the positioning pipe  21  and the positioning through hole  47  and a set of a positioning pin and a positioning hole, which is a known technique, can be adopted. In other words, by adopting at least one set of the positioning pipe  21  and the positioning through hole  47  as the component that positions the head case  11  and the electric substrate  14 , more space, amounting to the space saved with the above, for disposing the wiring and the mounted components  44  can be obtained on the electric substrate  14  and a reduction in the size of the electric substrate  14  can be achieved. 
     Furthermore, in the exemplary embodiments described above, while the nozzle rows  37   a  have been provided in the transport direction (the Y direction) of the medium  2 , a configuration in which the nozzle rows  37   a  are provided in a direction inclined from the transport direction (the Y direction) of the medium  2  can be adopted as well. 
     Furthermore, the liquid ejecting head  3  of each exemplary embodiment described above is a so-called serial head that performs printing operation by ejecting a liquid while the carriage  4  reciprocates in the X direction; however, a so-called line head in which, by arranging a plurality of liquid ejecting heads  3  in the X direction, the dimension of the plurality of liquid ejecting heads  3  in the X direction becomes larger than the size of the medium  2  in the width direction (the X direction) can be adopted. 
     Furthermore, a description has been given above with an ink jet liquid ejecting head, which is a type of liquid ejecting head, as an example; however, the present disclosure can adopt other liquid ejecting heads that adopt a configuration in which the flow path member and the electric substrate are positioned and layered. For example, the present disclosure can also be applied to a color material ejecting head used to manufacture a color filter of a liquid crystal display and the like, an electrode material ejecting head used to form electrodes of an organic electroluminescence (EL) display and a field emission display (FED), a bio-organic matter ejecting head used to manufacture biochips (biotips).