Patent Publication Number: US-9889661-B2

Title: Liquid ejecting head and manufacturing method for liquid ejecting head

Description:
The entire disclosure of Japanese Patent Application No: 2016-074968, filed Apr. 4, 2016 is expressly incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting head such as an ink jet recording head that ejects liquid from a nozzle and a manufacturing method for the liquid ejecting head. 
     2. Related Art 
     For example, there is an image recording apparatus such as an ink jet printer or an ink jet plotter as a liquid ejecting apparatus on which a liquid ejecting head is mounted, but the liquid ejecting head is also applied to various manufacturing apparatuses by taking advantage of a recent feature in which it is possible to accurately land a very small amount of liquid at a predetermined position. For example, the liquid ejecting head is applied to a display manufacturing apparatus which manufactures a color filter of a liquid crystal display or the like, an electrode forming apparatus which forms an electrode of an organic electro luminescence (EL) display, a field emission display (FED), or the like, and a chip manufacturing apparatus which manufactures a bio chip (bio-chemical element). Then, a recording head for the image recording apparatus ejects liquid ink, and a color material ejecting head for the display manufacturing apparatus ejects solution of each color material of red (R), green (G), and blue (B). In addition, an electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and a bio-organic material ejecting head for the chip manufacturing apparatus ejects a bio-organic material solution. 
     The liquid ejecting head is provided with a liquid ejecting unit that is provided with a nozzle that ejects liquid, a pressure chamber that links with the nozzle, a piezoelectric element (type of an actuator) that generates pressure variation in liquid within the pressure chamber, and the like, a base member to which the liquid ejecting unit is fixed, and a flow path member that supplies liquid to the pressure chamber of the liquid ejecting unit. Here, the flow path member has an internal flow path and is formed using resin (synthetic resin). Therefore, during formation, there is a concern that warping is generated in the flow path member. In particular, the flow path member that is attached to the liquid ejecting head provided with a plurality of liquid ejecting units tends to be long and warping tends to occur. Therefore, a component is disclosed that is configured such that the flow path member is attached to a reinforcing member and warping of the flow path member is corrected (for example, JP-A-2012-131152). Then, the reinforcing member is attached to a base member by a screw and the like at a plurality of locations. 
     Note that, the reinforcing member has rigidity to the extent that warping of the flow path member is able to be corrected. Therefore, when the reinforcing member is attached to the base member by the screw and the like, there is a concern that the base member is distorted in response to reaction force that is received from the reinforcing member. When the base member is distorted, there is a concern that the posture of the liquid ejecting unit is changed and the position of the nozzle is deviated from a prearranged position. As a result, there is a concern that a landing position of liquid droplets that are ejected from the nozzle toward the recording medium is deviated from the prearranged position. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a liquid ejecting head that is able to suppress distortion of a base member while correcting warping of a laminated member such as a flow path member, and a manufacturing method for a liquid ejecting head. 
     According to an aspect of the invention, there is provided a liquid ejecting head including a liquid ejecting unit that has a nozzle surface to which the nozzle is open, a base member to which the liquid ejecting unit is fixed, and a cover member that is attached to the base member and on which a laminated member is laminated, in which the cover member has a fixing portion to which the laminated member is fixed and a fragile portion that has lower rigidity than the fixing portion, and is attached to the base member by fixing the fragile portion to the base member. 
     According to the aspect of the invention, even if the laminated member is distorted, it is possible to correct distortion of the laminated member using the fixing portion. Thereby, connection of the laminated member and another member that is connected to the laminated member is easy. For example, even in a case where the laminated member has a plurality of protruding parts and the plurality of protruding parts are connected to another member, connection of the laminated member and another member is easy since a position of each protruding part with respect to the other member tends not to be deviated. In addition, in a case where a liquid flow path is formed along which the liquid flows inside the laminated member, it is possible to suppress air bubbles remaining in the liquid flow path since distortion of the liquid flow path is suppressed. Furthermore, it is possible to suppress the reaction force that is generated by fixing since the cover member is fixed to the base member by the fragile portion. Thereby, it is possible to suppress force that is applied to the base member and it is possible to suppress distortion of the base member. As a result, it is possible to suppress positional deviation of the liquid ejecting head. 
     In addition, in the configuration described above, it is desirable that the cover member have side surfaces that face each other interposing the base member therebetween, the fixing portion be formed between the side surfaces that face each other, the fragile portion be formed on the side surfaces, and a gap between side surfaces that face each other be larger than the width of the base member that is interposed between the side surfaces. 
     According to the configuration, when the base member is inserted between the side surfaces and the cover member is fixed to the base member, it is possible to easily insert the base member between the side surfaces. As a result, fixing of the cover member and the base member is easy. 
     Furthermore, in the configuration described above, it is desirable that the fragile portion that is formed on one side surface out of the side surfaces that face each other extend from the one side surface toward another side surface, and the fragile portion that is formed on the one side surface and the base member be fixed by a fixing member more at the other side surface side than the one side surface. 
     According to the configuration, it is possible to suppress the fixing member from protruding further to the outside of the opposite side of the other side surface than the one side surface. Thereby, it is possible to reduce the size of the liquid ejecting head. 
     In addition, in any of the configurations described above, it is desirable that the side surfaces that face each other be disposed with positions in a longitudinal direction of the base member deviated from each other, and the fragile portions be disposed uniformly along the longitudinal direction of the base member at each side surface. 
     According to the configuration, fixing of the cover member and the base member is stable since the fragile portions are fixed to the base member at uniform positions in the longitudinal direction at each side surface of the cover member. In addition, a degree of freedom of design increases since the positions in the longitudinal direction of the base member on both side surfaces may not be aligned. 
     Furthermore, in each of the configurations described above, it is desirable that the gap between the side surfaces that face each other be formed to become larger from the opposite side from the base member toward the base member side, and the fragile portions extend further outside than the end of the side surfaces on the base member side in a direction that is orthogonal to the nozzle surface. 
     According to the configuration, when the base member is inserted between the side surfaces and the cover member is fixed to the base member, it is possible to more easily insert the base member between the side surfaces. In addition, it is possible to suppress spread of the side surfaces since the fragile portions extend further outside than the end of the side surface. As a result, it is possible to further reduce the size of the liquid ejecting head. 
     In addition, in each of the configurations described above, it is desirable that a connection member be provided between the fixing portion and the base member, and the laminated member be connected to the connection member interposing the fixing portion therebetween. 
     According to the configuration, it is easy to connect the laminated member and the connection member. In particular, in a case where the laminated member has a plurality of protruding parts and the plurality of protruding parts are connected to the connection member, connection of the laminated member and the connection member is easy since a position of each protruding part with respect to the connection member tends not to deviate. 
     Furthermore, in any of the configurations described above, it is desirable to adopt a configuration in which a circuit board is provided that supplies a driving signal to the liquid ejecting unit, the cover member is formed of metal and has a surface along the circuit board, and the laminated member is provided with a liquid flow path along which liquid flows that is supplied to the nozzle. 
     According to the configuration, it is possible for heat that is generated in the circuit board to escape to the cover member. In addition, it is possible to cool the cover member using liquid that flows along the liquid flow path since the laminated member is provided with the liquid flow path. As a result, it is possible to effectively perform heat dissipation of the circuit board. 
     According to another aspect of the invention, there is provided a manufacturing method for a liquid ejecting head including a liquid ejecting unit that has a nozzle surface to which the nozzle is open, a base member to which the liquid ejecting unit is fixed, and a cover member that has a fixing portion to which a laminated member is fixed and a fragile portion that has lower rigidity than the fixing portion, the manufacturing method including fixing the laminated member to the fixing portion, and deforming the fragile portion to the base member side and fixing to the base member. 
     According to the aspect of the invention, even if the laminated member is distorted, it is possible to correct distortion of the laminated member using the fixing portion. In addition, it is possible to provide a gap for absorbing a dimensional error caused by a manufacturing error and the like between the base member and the fragile portion since the fragile portion is deformed to the base member side and fixed to the base member. Then, it is possible to suppress reaction force that is generated by deforming the fragile portion since the fragile portion has lower rigidity than the fixing portion. As a result, it is possible to suppress distortion of the base member. 
    
    
     
       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 perspective view describing an internal configuration of a printer. 
         FIG. 2  is an exploded perspective view of a recording head viewed from obliquely above. 
         FIG. 3  is a sectional view of the recording head. 
         FIG. 4  is a bottom surface view of the recording head. 
         FIG. 5  is a sectional view of a unit head. 
         FIG. 6  is a sectional view of an enlarged fixing portion of a fragile portion of a metal cover and a metal base. 
         FIG. 7  is a front surface view of the enlarged fixing portion of the fragile portion of the metal cover and the metal base. 
         FIG. 8  is a sectional view describing fixing of the fragile portion of the metal cover to the metal base. 
         FIG. 9  is a sectional view describing fixing of the fragile portion of the metal cover to the metal base. 
         FIG. 10  is a sectional view of an enlarged fixing portion of a fragile portion of a metal cover and a metal base in a second embodiment. 
         FIG. 11  is a front surface view of the enlarged fixing portion of the fragile portion of the metal cover and the metal base in the second embodiment. 
         FIG. 12  is a sectional view of an enlarged fixing portion of a fragile portion of a metal cover and a metal base in a third embodiment. 
         FIG. 13  is a front surface view of the enlarged fixing portion of the fragile portion of the metal cover and the metal base in the third embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Embodiments of the invention will be described below with reference to the drawings. Note that, in the embodiments described below, there are various limitations as preferred specific examples of the invention, but the scope of the invention is not limited to these aspects unless particular limitations of the invention are otherwise stated in the explanation below. In addition, in the description below, an ink jet recording head (hereinafter, recording head)  3  that is mounted on an ink jet printer (hereinafter, printer)  1  which is one type of a liquid ejecting apparatus is given as an example of the liquid ejecting head of the invention. 
     The configuration of the printer  1  will be described with reference to  FIG. 1 . The printer  1  is an apparatus which performs recording of an image or the like by ejecting ink in liquid form on the front surface of a recording medium  2  such as recording paper. The printer  1  is provided with the recording head  3  that is provided with a plurality of liquid ejecting units  4 , a transport mechanism  5  that transports the recording medium  2 , a medium support portion  6  (also referred to as a platen) that supports the recording medium  2  which is transported to a position facing a nozzle surface of the liquid ejecting unit  4 , and the like in a casing  7 . 
     The recording head  3  in the embodiment is a long line head in a direction (Y direction) in which a plurality (four in the embodiment) of liquid ejecting units  4  are attached lined up in the direction (Y direction in  FIG. 1  and the like) which intersects with the transport direction (X direction in  FIG. 1  and the like) of the recording medium  2 . A liquid supply tube  9  that is linked inside an ink cartridge  8  in which ink that is a type of liquid is retained is connected to the recording head  3 . Ink from the ink cartridge  8  is supplied to the recording head  3  via the liquid supply tube  9 . Note that, it is also possible to adopt a configuration in which the ink cartridge is mounted on the recording head. In addition, a gas supply tube  10  that supplies gas (air in the embodiment) to the recording head using a pump which is not shown in the drawings and a wiring member  11  such as FFC that supplies a driving signal and the like from a control portion which is not shown in the drawings to the recording head  3  are connected to the recording head  3 . 
     The transport mechanism  5  is provided with a first transport roller  12   a  that is disposed in an upper and lower pair further to the upstream side in the transport direction of the recording medium  2  than the medium support portion  6  and a second transport roller  12   b  that is disposed in the upper and lower pair further to the downstream side in the transport direction than the medium support portion  6 . The recording medium  2  from the supply side is transported toward the discharge side to pass above the medium support portion  6  in a state of being interposed by the upper and lower roller by driving of the transport rollers  12   a  and  12   b . Note that, in  FIG. 1 , illustration of the upper roller out of the upper and lower pair of rollers is omitted. In addition, the transport mechanism is constituted by an endless belt or a drum, and in such a configuration, the belt or the drum function as the medium support portion. Furthermore, as the medium support portion, it is also possible to adopt a configuration in which the recording medium is adsorbed by electrostatic force and a configuration in which the recording medium is adsorbed in response to generation of negative pressure. 
       FIG. 2  is an exploded perspective view illustrating the configuration of the recording head  3 .  FIG. 3  is a sectional view of the recording head  3 .  FIG. 4  is a bottom surface view (or lower surface view) of the recording head  3 . Note that, a lamination direction (Z direction) of each configuring member of the recording head  3  is described below as appropriate as in an up and down direction. As shown in  FIGS. 2 and 3 , the recording head  3  in the embodiment is provided with a flow path member  13  (one type of laminated member in the embodiment) on which a flow path that supplies ink to each liquid ejecting unit  4  is formed, a pressure adjustment member  14  (one type of connection member in the invention) that adjusts pressure of ink that flows internally, a circuit board  15  that transmits the driving signal that controls each liquid ejecting unit  4 , a metal shield  16  that internally accommodates the pressure adjustment member  14  and the circuit board  15 , and liquid ejecting units  4  that are fixed to a lower surface of a metal base  51  (one type of base member in the invention) that configures the bottom surface of the metal shield  16 . 
     The flow path member  13  is formed internally by a liquid flow path along which ink flows and an air flow path along which air flows (neither shown in the drawings), and is a plate-like member made from a synthetic resin (for example, polypropylene (PP)) that supplies ink to each liquid ejecting unit  4 . The flow path member  13  in the embodiment is fixed to (in other words, laminated to) an upper surface  65  of the metal cover  52  described later (one type of cover member in the invention). As shown in  FIG. 2 , a plurality of (four in the embodiment) liquid supply tube connecting portions  41  that are connected by the liquid supply tube  9  corresponding to each color are formed on the upper surface of the flow path member  13 . The liquid supply tube connecting portions  41  are linked to a liquid outflow port  42  that is formed on the lower surface of the flow path member  13  via the liquid flow path inside the flow path member  13 . The liquid flow path in the embodiment is branched in the middle such that ink that flows from one liquid supply tube connecting portion  41  is distributed to four liquid ejecting units  4 , and four liquid outflow ports  42  are linked. That is, one liquid supply tube connecting portion  41  is linked to four liquid outflow ports  42  via the liquid flow path. In addition, a plurality of (two in the embodiment) gas supply tube connecting portions  43  that are connected by the gas supply tube  10  are formed on the upper surface of the flow path member  13 . The gas supply tube connecting portions  43  are linked to a gas outflow port  44  that is formed on the lower surface of the flow path member  13  via the gas flow path inside the flow path member  13 . The gas flow path in the embodiment is branched in the middle, and is linked to four gas outflow ports  44 . That is, one gas supply tube connecting portion  43  is linked to four gas outflow ports  44  via the gas flow path. 
     Note that, a plurality of (in detail, eight) the gas outflow ports  44  in the embodiment are formed along the longitudinal direction (Y direction) of the flow path member  13  in substantially the center of a direction (X direction) which is orthogonal to the longitudinal direction (Y direction) of the flow path member  13 . In addition, the liquid outflow ports  42  in the embodiment are respectively arranged side by side along the Y direction at both sides in the X direction of the columns of the gas outflow ports  44 . That is, the columns of the liquid outflow ports  42  in which a plurality of (in detail, eight) liquid outflow ports  42  are arranged side by side are formed in two columns that interpose the column of the gas outflow ports  44 . Furthermore, the liquid outflow ports  42  and the gas outflow ports  44  in the embodiment are formed in a cylindrical shape and protrudes downward from the lower surface of the flow path member  13 . The diameter of the liquid outflow ports  42  are formed to be smaller than the diameter of the gas outflow ports  44 . In addition, a flow path member through hole  80  through which the flow path member  13  passes through in the plate thickness direction is established at a center portion at four corners and in the longitudinal direction (Y direction) of the flow path member  13 . As shown in  FIG. 3 , the flow path member  13  is fixed to the upper surface  65  of the metal cover  52  by fixing a flow path member fixing screw  81  to a flow path member fixing screw hole  79  that is formed on the upper surface  65  of the metal cover  52  through the flow path member through hole  80  in a state in which the bottom surface of the flow path member  13  is abutted to the upper surface  65  of the metal cover  52 . 
     The pressure adjustment member  14  is a member made from synthetic resin that is connected below the flow path member  13  (liquid ejecting unit  4  side) that interposes the upper surface  65  of the metal cover  52  therebetween. The pressure adjustment member  14  is disposed between the upper surface  65  of the metal cover  52  and the metal base  51 . A plurality of liquid inflow ports  46  that correspond to the liquid outflow ports  42  of the flow path member  13  and gas inflow ports  47  that correspond to the gas outflow ports  44  of the flow path member  13  are respectively formed on the upper surface of the pressure adjustment member  14 . As shown in  FIG. 3 , a connecting portion of the liquid outflow ports  42  and the liquid inflow ports  46  and a connecting portion of gas outflow ports  44  and the gas inflow ports  47  are connected below (that is, within an accommodating space  68  which will be described later) the upper surface  65  of the metal cover  52 . The liquid inflow ports  46  are linked to a liquid outflow pipe  48  that protrudes below the pressure adjustment member  14  via a liquid flow path which is not shown in the drawings that is formed inside the pressure adjustment member  14 . Note that, the liquid flow path inside the pressure adjustment member  14  is configured to be able to pressurize ink within the liquid flow path in response to air that flows in from the gas inflow ports  47 . Therefore, if gas is driven by a pump and sent to the pressure adjustment member  14  via the gas supply tube  10 , the flow path member  13 , and the gas inflow ports  47 , it is possible to increase pressure within the liquid flow path, and thus, it is possible to increase pressure within the liquid ejecting unit  4 . Then, for example, a cleaning operation and the like are performed in which the nozzle surface (that is, the lower surface of a nozzle plate  23 ) of the liquid ejecting unit  4  is wiped by a wiper which is not shown in the drawings and the like in a state in which ink is caused to overflow from each nozzle  24  by controlling pressure of ink within the liquid ejecting unit  4 . 
     As shown in  FIG. 3 , the metal shield  16  is a member made from metal on which the accommodating space  68  is formed that internally accommodates the pressure adjustment member  14  and the circuit board  15 . The metal shield  16  is provided with the metal base  51  that has high rigidity that is attached on the upper surface to the pressure adjustment member  14  and the circuit board  15  and fixed on the lower surface to the plurality of liquid ejecting units  4 , and the metal cover  52  with a thin sheet shape that covers the pressure adjustment member  14  and the circuit board  15 . The metal base  51  is a plate material along a long X-Y plane in the Y direction as indicated in  FIG. 2 . The metal base  51  in the embodiment consists of aluminum, and as shown in  FIG. 4 , is formed in a long parallelogram shape in the Y direction in planar view. In addition, the metal base  51  is grounded by being electrically connected to a ground line G indicated in  FIG. 3 . A plurality of base through holes  59  into which the liquid outflow pipes  48  of the pressure adjustment member  14  are inserted are established in a state of passing through the plate thickness direction in a region in which the pressure adjustment member  14  of the metal base  51  is fixed. As shown in  FIG. 3 , the liquid outflow pipes  48  of the pressure adjustment member  14  pass through the base through holes  59  and are connected to the liquid ejecting unit  4  (in detail, the liquid introduction inlet  60 ). 
     In addition, a step  54  in which an upper surface of the metal base  51  is lowered by one step is formed on an end portion on one side (right side in  FIGS. 2 and 3 ) in the X direction of the metal base  51 . As shown in  FIG. 2 , a circuit board fixing screw hole  55  for fixing the circuit board  15  that supplies the driving signal to the liquid ejecting unit  4  is established on the side surface of the step  54 . Thereby, the circuit board  15  is fixed on the metal base  51  by fixing a circuit board fixing screw  57  to the circuit board fixing screw hole  55  through a substrate through hole  56  that is formed in the circuit board  15  in a state in which the circuit board  15  (in detail, a circuit base material  62 ) is mounted on the upper surface of the step  54  along the side surface (that is, the Y-Z plane) of the step  54 . That is, the circuit board  15  in the embodiment is fixed in a state of being erected from the metal base  51  along the Y-Z plane. Accordingly, as shown in  FIG. 3 , in a state in which the metal cover  52  is attached to the metal base  51 , the circuit board  15  is disposed along the side surface  66  on one side (step  54  side) of the metal cover  52 . In other words, the side surface  66  on one side of the metal cover  52  is formed along the circuit board  15 . Note that, the metal cover  52  and the circuit board  15  may not be disposed in parallel. That is, the circuit board  15  may be slightly inclined to the side surface  66  on one side of the metal cover  52 . In short, “the circuit board  15  is disposed along the side surface  66 ” is not limited to a case where the circuit board  15  is lined up parallel to the side surface  66 , and includes a case where the circuit board  15  is slightly inclined to the side surface  66 . 
     Note that, a wiring that has a ground potential in the circuit board  15  and a metal base  51  are conducted by the circuit board fixing screw  57 . In addition, the circuit board  15  is provided with the long circuit base material  62  in a Y direction on which a circuit and the like is formed for driving a piezoelectric element  32  that consists of the wiring and the like and a connector  63  that is connected to the wiring member  11  which is formed on the circuit base material  62 . The connector  63  in the embodiment is an upper end portion of the circuit base material  62 , and one connector  63  is disposed close to one side (left side in  FIG. 2 ) in the Y direction. In addition, the connector  63  is disposed on one surface inside the circuit base material  62  (pressure adjustment member  14  side). 
     Furthermore, a concave portion  69  that is concave inside is formed on the side surface on both sides in the X direction of the metal base  51  (refer to  FIGS. 2 and 6 ). The concave portion  69  is a space that accommodates fragile portions  73  which will be described later, and is formed at a position which corresponds to the fragile portions  73 . Five concave portions  69  in the embodiment are arranged side by side on the respective side surfaces of the metal base  51 . Then, a metal cover fixing screw hole  70  is established on the plane (that is, Y-Z plane) along the side surface in the concave portion  69 . 
     The metal cover  52  is a long cover member in the Y direction that is formed in a state to cover spaced apart the pressure adjustment member  14  and the circuit board  15 . The metal base  52  in the embodiment consists of an electrogalvanized steel plate (SECC and the like), and in the same manner as the metal base  51 , is formed in a long parallelogram shape in the Y direction in planar view. As shown in  FIG. 3 , the metal cover  52  is attached to the metal base  51  and forms the accommodating space  68  with the metal base  51 . In detail, the metal cover  52  is provided with the upper surface  65  along the X-Y plane that covers the upper surface of the pressure adjustment member  14 , an upper surface step portion  67  that is formed in a step shape that is lowered by one step from the end portion of one side in the X direction of the upper surface  65 , and two side surfaces  66  that interpose the metal base  51  therebetween and face each other. In other words, the upper surface  65  and the upper surface step portion  67  are formed between the two side surfaces  66 . That is, the side surface  66  is a part that extends downward respectively from another side end in the X direction of the upper surface  65  and one side end in the X direction of the upper surface step portion  67 . In addition, the upper surface  65  has rigidity to the extent to function as a correction portion that corrects distortion of the flow path member  13  while the flow path member  13  is attached. Note that, the upper surface  65  of the metal cover  52  is equivalent to the fixing portion in the invention. 
     As shown in  FIGS. 2 and 3 , a first opening  76  in which the wiring member  11  is inserted is formed on the upper surface step portion  67  of the metal cover  52 . The wiring member  11  is inserted into the first opening  76  and the wiring member  11  and the connector  63  of the circuit board  15  are connected further below the first opening  76 . Note that, the first opening  76  in the embodiment is formed in a state of an edge that is curved to the exterior. In addition, a second opening  77  into which the liquid outflow ports  42  of the flow path member  13  is inserted and a third opening  78  into which the gas outflow ports  44  of the flow path member  13  are formed on the upper surface  65  of the metal cover  52 . That is, the liquid outflow ports  42  of the flow path member  13  are inserted into the second opening  77  and is connected to the liquid inflow port  46  of the pressure adjustment member  14  that is positioned below the second opening  77 . In addition, the gas outflow ports  44  of the flow path member  13  are inserted into the third opening  78  and is connected to the gas inflow port  47  of the pressure adjustment member  14  that is positioned below the third opening  78 . That is, the first opening  76 , the second opening  77 , and the third opening  78  are connection ports that link the accommodating space  68  and connect an internal space and an external space of the accommodating space  68 . 
     As shown in  FIGS. 2 and 3 , a plurality of fragile portions  73  with lower rigidity than the upper surface  65  and the side surface  66  are provided on the lower end portion of both side surfaces  66  of the metal cover  52 . The fragile portions  73  in the embodiment are respectively disposed uniformly along the Y direction (in other words, the longitudinal direction of the metal base  51 ) on the side surface  66 . That is, the fragile portions  73  are arranged side by side at an equal pitch on each side surface  66 , and a distance between the fragile portion  73  that is positioned at one end in the Y direction and one end of the side surface  66  and a distance between the fragile portion  73  that is positioned at the other end in the Y direction and the other end of the side surface  66  are respectively set to distances at an approximate half pitch. In addition, a through hole  71  into which a metal cover fixing screw  72  (one type of fixing member in the invention) is inserted is established in each fragile portion  73 . As shown in  FIG. 3 , the side surface  66  of the metal cover  52  is fixed to the metal base  51  by fixing the metal cover fixing screw  72  to the metal cover fixing screw hole  70  of the metal base  51  through the through hole  71  of the fragile portion  73  in a state in which the metal base  51  is inserted between the side surfaces  66  that face each other (in other words, a state in which the metal base  51  is interposed between the side surfaces  66 ). In other words, the metal cover  52  is attached to the metal base  51  by fixing to the metal base  51  of the fragile portions  73 . Note that, the metal cover  52  has a ground potential since the metal base  51  and the metal cover  52  are conducted by the metal cover fixing screw  72 . That is, the metal base  51  and the metal cover  52  are conducted and joined on the side surface  66  by the metal cover fixing screw  72 . 
       FIG. 6  is a sectional view of an enlarged fixing portion of the fragile portions  73  of the metal cover  52  and a metal base  51 .  FIG. 7  is a front surface view of an enlarged fixing portion of the fragile portions  73  of the metal cover  52  and a metal base  51 . The fragile portions  73  in the embodiment extend further outside (lower side) than an end of the lower side (in other words, metal base  51  side) of the side surface  66  in the Z direction (that is, a direction that is orthogonal to a nozzle surface) and extend in the X direction from one side surface  66  toward the other side surface  66  (alternatively, one side surface  66  from the other side surface  66 ). In short, the fragile portions  73  extend from the side surface  66  toward the lower side and the inside. 
     Described in further detail, as shown in  FIGS. 6 and 7 , the fragile portion  73  is formed within a cutout portion  88  in which a portion of the lower end of the side surface  66  is cut out, and consists of two arm portions  74  that extend from the cutout portion  88  toward the lower side and the inside of the side surface  66  and a fixed base portion  75  that is formed on the tip end of the two arm portions  74 . The two arm portions  74  are bent in the middle such that the fixed base portion  75  is along a plane (Y-Z plane) on which the metal cover fixing screw hole  70  is formed inside the concave portion  69  of the metal base  51 . Then, the through hole  71  into which the metal cover fixing screw  72  is inserted is formed at a position that corresponds to the metal cover fixing screw hole  70  of the fixed base portion  75 . Thereby, the fragile portion  73  is fixed inside the concave portion  69  when the metal cover fixing screw  72  is fixed in the metal cover fixing screw hole  70  of the metal base  51  through the through hole  71  in a state in which the fragile portion  73  is accommodated inside the concave portion  69  of the metal base  51 . Accordingly, the fragile portion  73  and the metal base  51  are fixed by the metal cover fixing screw  72  further at the other side surface  66  side than the one side surface  66  (alternatively, further on one side surface  66  side than the other side surface  66 ). In other words, the fragile portion  73  and the metal base  51  are fixed by the metal cover fixing screw  72  further to the inside than the side surface  66 . In the fixed state, a part or all of the metal cover fixing screw  72  is accommodated inside the concave portion  69  of the metal base  51 . Then, the metal cover  52  is fixed to the metal base  51  by fixing each fragile portion  73  and the concave portions  69  that correspond thereto. Note that, the fragile portion  73  in the embodiment is formed with a narrower width than the width of the concave portion  69  of the metal base  51  (dimension in the Y direction) and a narrower width than the width of the cutout portion  88  of the metal cover  52 . 
     In addition, as shown in  FIG. 4 , both side surfaces  66  of the metal cover  52  in the embodiment are disposed at positions in the longitudinal direction (Y direction) of the metal base  51  that are deviated from each other along both side surfaces of the metal base  51  formed in a long parallelogram shape in the Y direction. Therefore, viewed from the X direction, both side surfaces  66  do not overlap with both end portions of the metal cover  52  in the Y direction and either becomes only one. That is, viewed from the X direction, a region in which both side surfaces  66  overlap and a region in which both side surfaces  66  do not overlap are formed. Then, since the respective fragile portions  73  are disposed uniformly on both side surfaces  66  with positions deviated from each other, a part or all of the fragile portions  73  are disposed at positions that do not overlap viewed from the X direction. In short, the fragile portions  73  in the embodiment are disposed asymmetrically to a virtual line that passes through the center of the metal cover  52  in the X direction. 
     Furthermore, as shown in  FIG. 3 , the dimension between the side surfaces  66  of the metal cover  52  that face each other (that is, the gap between the side surfaces  66 ) is formed to become larger from the upper surface  65  side (that is, opposite side from the metal base  51 ) toward the metal base  51  side. In the embodiment, the side surfaces  66  are formed in a state of being slightly inclined to the Y-Z plane so as to gradually become larger from the upper surface  65  side toward the metal base  51  side. In short, in sectional view, an outline of the metal base  51  is formed in a substantially trapezoidal shape. Then, a gap W 1  between the side surfaces  66  of the region that corresponds to at least the metal base  51  (that is, the gap W 1  of the lower end portion of the side surfaces  66 ) out of the gap between the side surfaces  66  is formed to be larger than a dimension W 2  of the metal base  51  that is interposed between the side surfaces  66 . Therefore, a slight gap is formed between the side surface  66  of the metal cover  52  and the metal base  51 . Note that, in the embodiment, the thickness of each portion of the metal cover  52  is aligned with a substantially constant thickness. 
     The liquid ejecting unit  4  is fixed by a screw fastening or an adhesive to the lower surface of the metal base  51  (that is, surface of the medium support portion  6  side) lined up in the Y direction in a state in which the respective relative positions are specified. As shown in  FIG. 2 , each liquid ejecting unit  4  is provided with a plurality of unit heads  83  (referred to as a head chip), a flow path structure  84  in which the supply flow path (not shown in the drawings) is formed along which ink that is supplied to each unit head  83  flows, and a protective plate  85  that protects each unit head  83 . The unit heads  83  are configured such that the configuring members such as a nozzle plate  23  on which the nozzles  24  as will be described later are established, a substrate on which the flow path that is linked to the nozzles  24  is formed, an actuator unit  17  that is a driving source that discharges ink, and the like are laminated. The unit head  83  exhibits a substantially parallelogram shape in planar view from the lower surface of the nozzle plate  23  (surface on the side at which ink is ejected from the nozzles  24 ). That is, as shown in  FIG. 4 , a nozzle column  24   a  in which a plurality of nozzles  24  are arranged side by side are provided inclined to the transport direction (X direction) of the recording medium  2  and a side by side direction (Y direction) of the liquid ejecting unit  4 , and is formed such that the outline of the unit head  83  that matches the inclination of the nozzle column  24   a  is a substantially parallelogram shape. Note that, the inclination angle of the nozzle column  24   a  is determined according to the formation pitch of the nozzle  24  and the recording resolution in the X direction. In the embodiment, a total of two nozzle columns  24   a  are provided on one unit head  83 . Then, in each liquid ejecting unit  4 , a total of six unit heads  83  are disposed lined up along the Y direction that is the side by side direction of the liquid ejecting unit  4 . Accordingly, in the embodiment, each liquid ejecting unit  4  respectively has  12  nozzle columns  24   a.    
     The protective plate  85  is a plate-shaped plate material made from metal common to each unit head  83  that is provided in the liquid ejecting unit  4 . A nozzle exposure opening  86  that exposes the nozzle  24  which is formed on the nozzle plate  23  is open to a position that corresponds to the nozzle plate  23  of each unit head  83  on the protective plate  85 . The nozzle exposure opening  86  in the embodiment exhibits a long parallelogram shape in the nozzle column direction (Xa direction). Each unit head  83  is joined using adhesive to the upper surface of the protective plate  85  (surface on the opposite side from the medium support portion  6 ) in a state in which the nozzle  24  is exposed to the corresponding nozzle exposure opening  86 . 
     The flow path structure  84  is a member in which a plurality of members that distribute and supply ink that is sent from the ink cartridge  8  to each unit head  83  that are joined to the lower surface side of the flow path structure  84 . A plurality of liquid introduction inlets  60  are established on the upper surface of the flow path structure  84  and ink is introduced to the internal flow path from the liquid introduction inlets  60 . In the embodiment, the liquid introduction inlets  60  that correspond to a total of four colors of ink are provided to the flow path structure  84 . Filters which are not shown in the drawings are respectively disposed in the middle of the supply flow paths that correspond to each color inside the flow path structure  84 , and air bubbles or foreign matter are removed from the ink that flows along the supply flow path. Each supply flow path is branched in a branched flow path of a number according to a number of the unit heads  83  that are provided in the liquid ejecting unit  4  inside the flow path structure  84 , and is linked to the liquid introduction path  21  of the plurality of unit heads  83 . 
       FIG. 5  is a sectional view of the unit head  83 . As shown in  FIG. 5 , the unit head  83  in the embodiment is attached to a head casing  19  in a state in which the actuator unit  17  and a flow path unit  18  are laminated. 
     The head casing  19  in the embodiment is a box-shaped member made of a synthetic resin. As shown in  FIG. 5 , an actuator accommodation space  20  and a through space  22  that are long spaces along the nozzle column direction are formed in the center portion of the head casing  19 . The actuator accommodation space  20  is a space in which the actuator unit  17  is accommodated, and is formed in a state of being concave in the middle in the plate thickness direction from the lower surface (that is, a direction orthogonal to the lower surface) of the head casing  19  by only the thickness of the actuator unit  17 . The through space  22  is formed in a state of being linked to a ceiling surface on the top surface side of the actuator accommodation space  20 , and passing through the head casing  19  in the plate thickness direction. A flexible substrate  35  that supplies the driving signal to the piezoelectric element  32  (described later) is disposed in the through space  22  and the actuator accommodation space  20 . Note that, although illustration is omitted, the flexible substrate  35  extends outside of the unit head  83  from the upper surface opening of the through space  22 , and is connected to an aggregate substrate (not illustrated) that is provided in the flow path structure  84 . Then, the aggregated substrate is connected to the circuit board  15  via a cable that is not illustrated. For example, the cable is connected to the circuit board  15  through a gap between the metal base  51  and the metal cover  52 . In addition, as shown in  FIG. 5 , the liquid introduction path  21  along which ink flows is formed inside the head casing  19 . The lower end of the liquid introduction path  21  is connected to a common liquid chamber  26  which will be described later. In the embodiment, two liquid introduction paths  21  are formed corresponding to the nozzle columns  24   a  which are formed in two columns. 
     The flow path unit  18  is connected to the lower surface of the head casing  19 . The flow path unit  18  is a long substrate along the nozzle column direction that consists of a linking substrate  25 , a nozzle plate  23 , and a compliance substrate  37  that are laminated. For example, the linking substrate  25  is a substrate that is manufactured from a silicon single crystal substrate. As shown in  FIG. 5 , the common liquid chamber  26  in which ink is retained common to each pressure chamber  30  and that is linked to the liquid introduction path  21 , an individual linking path  27  that individually supplies ink from the common liquid chamber  26  to each pressure chamber  30 , and the nozzle linking path  28  that is linked to the pressure chamber  30  and the nozzle  24  are formed on the linking substrate  25  by anisotropic etching. The common liquid chamber  26  is a long space portion along the nozzle column direction and is formed in two columns corresponding to the liquid introduction path  21 . A plurality of individual linking paths  27  and the nozzle linking paths  28  are formed along the side by side direction of the pressure chamber  30  (in other words, the nozzle column direction). 
     The nozzle plate  23  is a substrate made of silicon (for example, a silicon single crystal substrate) that is joined to the lower surface of the linking substrate  25  (that is, surface on the opposite side from a pressure chamber forming substrate  29 ). The nozzle plate  23  in the embodiment is joined to a region that is separated from the compliance substrate  37  so as not to overlap with the compliance substrate  37 . In other words, the nozzle plate  23  is joined to the region that is separated from the opening on the lower surface side of the common liquid chamber  26  of the linking substrate  25 . The plurality of nozzles  24  are established on the nozzle plate  23  in a straight line shape (in other words, a column shape) along the longitudinal direction of the nozzle plate  23 . That is, the nozzle column  24   a  is formed. The plurality of established nozzles  24  (the nozzle column  24   a ) are uniformly provided at a pitch corresponding to the dot formation density from the nozzle  24  on one end side up to the nozzle  24  on the other end side. Note that, the lower surface of the nozzle plate  23  is equivalent to the nozzle surface in the invention. 
     The compliance substrate  37  is a substrate that has flexibility that is joined to the region that corresponds to the common liquid chamber  26  on the lower surface of the linking substrate  25 . That is, the compliance substrate  37  is joined to the region that does not cover the nozzle plate  23  of the linking substrate  25 . The compliance substrate  37  in the embodiment is a substrate on which a sealing film  39  that has flexibility with low rigidity is laminated on a fixed substrate  38  that consists of a rigid material such as metal. The region that faces the common liquid chamber  26  of the fixed substrate  38  is an opening portion that is removed in the thickness direction. Therefore, the lower surface of the common liquid chamber  26  functions as a compliance portion that is sealed by only the sealing film  39  and absorbs pressure variation of ink within the common liquid chamber  26 . 
     As shown in  FIG. 5 , the actuator unit  17  in the embodiment is a composite substrate formed of laminated substrates such as the pressure chamber forming substrate  29 , a vibration plate  31 , and a sealing plate  33 . The actuator unit  17  is formed in a size to be accommodatable in the actuator accommodation space  20  of the head casing  19 , and is accommodated in the actuator accommodation space  20 . 
     For example, the pressure chamber forming substrate  29  is a substrate that is manufactured from a silicon single crystal substrate. A part of the pressure chamber forming substrate  29  is removed from the entirety in the plate thickness direction by anisotropic etching and the like, and a plurality of spaces that are to be the pressure chamber  30  are established along the nozzle column direction. The lower part of the space is partitioned by the linking substrate  25 , the upper part is partitioned by the vibration plate  31 , and constitutes the pressure chamber  30 . In addition, the space, that is, the pressure chamber  30  is formed to be long in a direction orthogonal to the nozzle column direction, the individual linking path  27  is linked to one end portion in the longitudinal direction, and the nozzle linking path  28  is linked to the other end portion. In addition, the plurality of pressure chambers  30  in the embodiment are formed along the nozzle column direction. 
     For example, the vibration plate  31  is a thin-film member that consists of an elastic film made from silicon dioxide (SiO 2 ) that is formed on the upper surface of the pressure chamber forming substrate  29  (that is, the surface on the opposite side from the linking substrate  25  side) and an insulation film made from zirconium dioxide (ZrO 2 ) that is formed on the elastic film. An upper opening of the space that is to be the pressure chamber  30  is sealed by the vibration plate  31 . In other words, the upper surface of the pressure chamber  30  is partitioned by the vibration plate  31 . A part which corresponds to the pressure chamber  30  on the vibration plate  31  (in detail, the upper opening of the pressure chamber  30 ) functions as a displaced portion that is displaced in a direction that is far from the nozzle  24  or in a direction that is close accompanying deflection of the piezoelectric element  32 . That is, a region which corresponds to the upper opening of the pressure chamber  30  on the vibration plate  31  is a driving region in which deflection is permissible. Then, the capacity of the pressure chamber  30  is changed by the deflection (displacement) of the driving region (displaced portion). Meanwhile, a region which is separated from the upper opening of the pressure chamber  30  on the vibration plate  31  is a non-driving region in which deflection is inhibited. 
     The piezoelectric elements  32  (equivalent to driving elements in the invention) are respectively laminated in a region (that is, driving region) which corresponds to each pressure chamber  30  on the upper surface (that is, the surface on the opposite side from the pressure chamber forming substrate  29  side of the vibration plate  31 ) of the vibration plate  31  (in detail, an insulation film of the vibration plate  31 ). The piezoelectric element  32  in the embodiment is a piezoelectric element of a so-called deflection mode. The plurality of piezoelectric elements  32  are established along the nozzle column direction corresponding to each nozzle  24 . For example, on each piezoelectric element  32 , a lower electrode layer that is an individual electrode, a piezoelectric body layer, and an upper electrode layer that is a common electrode are sequentially laminated in order from above the vibration plate  31 . Note that, it is also possible for the lower electrode layer to be the common electrode and the upper electrode layer to be the individual electrode according to the circumstance of the driving circuit or the wiring. When the piezoelectric element  32  that is configured in this manner applies an electric field according to potential differences of both electrodes between the lower electrode layer and the upper electrode layer, the piezoelectric element  32  deforms by deflection in the direction that is far from the nozzle  24  or in a direction that is close. 
     As shown in  FIG. 5 , the sealing plate  33  is a substrate on which a piezoelectric element accommodation space  34  that is able to accommodate the piezoelectric elements  32  is formed. The sealing plate  33  is joined on the vibration plate  31  in a state in which the piezoelectric elements  32  are accommodated in the piezoelectric element accommodation space  34 . In the embodiment, the piezoelectric element accommodation spaces  34  are formed in two columns which correspond to the columns of the piezoelectric elements  32  which are formed in two columns. A connection space  36  in which the sealing plate  33  is removed in the plate thickness direction is formed between the two piezoelectric element accommodation spaces  34 . The connection space  36  is linked to the through space  22 , and the end portion of the flexible substrate  35  that is inserted in the through space  22  is disposed inside of the connection space  36 . Then, the flexible substrate  35  and a lead wiring (not shown in the drawings) that extends from the piezoelectric element  32  are connected in the connection space  36 . 
     Then, the recording head  3  that is configured in the manner above supplies ink inside the individual unit heads  83  via the flow path member  13 , the pressure adjustment member  14 , and the flow path structure  84  by supplying ink from the ink cartridge  8 . The unit head  83  changes the capacity of the pressure chamber  30  by supplying the driving signal from the control portion to the piezoelectric element  32  via the wiring member  11 , the circuit board  15 , the flexible substrate  35 , and the like in a state in which the flow path from the liquid introduction path  21  to the pressure chamber  30  is filled with ink. By using the pressure variation of ink in the pressure chamber  30  accompanying the change of capacity, ink droplets are ejected from the nozzle  24  that is linked to the pressure chamber  30  via the nozzle linking path  28 . 
     Next, the manufacturing method of the recording head  3 , and in particular, the fixing method for the metal base  51  of the metal cover  52  will be described in detail.  FIG. 8  is a sectional view describing fixing of the fragile portion  73  to the metal base  51 .  FIG. 9  is a sectional view describing fixing of the fragile portion  73  to the metal base  51 . First, the liquid ejecting unit  4  is fixed to the lower surface of the metal base  51 , and the pressure adjustment member  14  and the circuit board  15  are fixed to the upper surface (refer to  FIG. 2  and the like). In addition, in a flow path member fixing process (equivalent to the laminated member fixing step in the invention), the flow path member  13  is fixed to the upper surface  65  of the metal cover  52 . By the fixing, distortion of the flow path member  13  is corrected. In short, the flow path member  13  is made from a synthetic resin, and warping tends to be generated during formation. In addition, in a case where the flow path member  13  fuses a plurality of members, warping is more likely to occur in response to heat during fusing. However, in the embodiment, it is possible to suppress warping of the flow path member  13  since the flow path member  13  is fixed to the upper surface  65  of the metal cover  52  by the flow path member fixing screw  81 . 
     The metal cover  52  is fixed to the metal base  51  if the liquid ejecting unit  4  or the like are fixed to the metal base  51 , and the flow path member  13  is fixed to the metal cover  52 . In detail, either one of the metal cover  52  or the metal base  51  is relatively moved toward the other end while matching both relative positions. Then, the plurality of liquid outflow ports  42  and the plurality of gas outflow ports  44  of the flow path member  13  that protrudes below the metal cover  52  are connected to the corresponding plurality of liquid inflow ports  46  and the plurality of gas inflow ports  47  of the pressure adjustment member  14 . In this case, as shown in  FIG. 8 , the fragile portions  73  of the metal cover  52  are inserted into the concave portions  69  of the corresponding metal bases  51 . Note that, the fragile portion  73  is in a state of being slightly separated from the surface on which the metal cover fixing screw hole  70  is formed in the concave portion  69 . That is, as shown by a broken line in  FIG. 9 , a slight gap is formed between the fragile portion  73  and the surface on which the metal cover fixing screw hole  70  of the concave portion  69  is formed. Then, in this state, the process transitions to the metal cover fixing step (cover member fixing step in the invention). In detail, as shown in  FIG. 9 , the metal cover fixing screw  72  is inserted into the through hole  71  of the fragile portion  73 , and the metal cover fixing screw  72  is tightened in the metal cover fixing screw hole  70  while the fragile portion  73  is deformed inside (that is, the metal base  51  side). When the metal cover fixing screw  72  is tightened until the last in the metal cover fixing screw hole  70 , the fragile portion  73  abuts with the side surface of the metal base  51  and is fixed to the metal base  51 . In the same manner, the metal cover  52  is fixed to the metal base  51  and the recording head  3  is manufactured by fixing each fragile portion  73  to the metal cover  52 . 
     In this manner, in the manufactured recording head  3 , since the flow path member  13  is fixed on the upper surface  65  of the metal cover  52 , for example, even if the flow path member  13  is distorted, it is possible to correct distortion of the flow path member  13  using the upper surface  65  of the metal cover  52 . Thereby, connection between the flow path member  13  and the pressure adjustment member  14  is easy. That is, since the position tends not to be deviated with respect to the plurality of the liquid outflow ports  42  of the flow path member  13  and the pressure adjustment member  14  of the plurality of gas outflow ports  44 , connection between the plurality of liquid outflow ports  42  and the plurality of gas outflow ports  44  and the corresponding plurality of liquid inflow ports  46  and the plurality of gas inflow ports  47  is easy. In addition, it is possible to suppress air bubbles remaining in the liquid flow path since distortion of the liquid flow path inside the flow path member  13  is suppressed. Then, it is possible to suppress the reaction force that is generated by fixing since the metal cover  52  is fixed to the metal base  51  by the fragile portion  73 . Thereby, it is possible to suppress force that is applied to the metal base  51  and it is possible to suppress distortion of the metal base  51 . In short, for example, when the metal cover that does not have a fragile portion is fixed to the metal base by the metal cover fixing screw, a recovery force that returns the metal cover to original position acts on the metal base, and the metal base deforms very slightly (for example, around several microns to several tens of microns). As a result, there is a concern that the position of the liquid ejecting unit that is attached to the metal base is deviated, and the nozzle position that is established on the nozzle surface of the liquid ejecting unit is deviated. In particular, in the embodiment, when the fixing portion of the metal cover and the metal base are disposed asymmetrically in the X direction, the force acting on the metal base is asymmetrical, and the metal base tends to distort. However, in the invention, since the metal base  51  is fixed by the fragile portion  73 , the recovery force of the fragile portion  73  is weak, and it is possible to suppress deformation in the metal base  51 . As a result, it is possible to suppress positional deviation of the recording head  3 , and thus, it is possible to suppress positional deviation of the nozzle  24 . 
     In addition, in the embodiment, since the gap between both side surfaces  66  is larger than the width of the metal base  51  in the X direction, when the metal base  51  is inserted between the side surfaces  66  and the metal cover  52  is fixed in the metal base  51 , it is possible to easily insert the metal base  51  between the side surfaces  66 . In particular, in the embodiment, since the gap between both side surfaces  66  is formed to become larger downward, when the metal cover  52  is fixed in the metal base  51 , it is possible to more easily insert the metal base  51  between the side surfaces  66 . As a result, fixing of the metal cover  52  and the metal base  51  is easy. Furthermore, since the positions in the Y direction of both side surfaces  66  are disposed deviated from each other, the positions in the Y direction may not be aligned and a degree of freedom of design increases. 
     Furthermore, since the fragile portion  73  in the embodiment is fixed inside the concave portion  69 , it is possible to suppress protrusion of the metal cover fixing screw  72  further outside in the X direction than the side surfaces  66 . That is, it is possible to reduce (alternatively, eliminate) the amount of protrusion from both side surfaces  66  of the metal cover fixing screw  72 . As a result, it is possible to reduce the size of the recording head  3 . Additionally, since the fragile portion  73  extends further to the lower side than the lower end of the side surfaces  66 , it is possible to suppress spread of the gap of the side surfaces  66  in comparison to the recording head in which the lower end of the side surface extends to the same position as the lower end of the fragile portion. As a result, it is possible to further reduce the size of the recording head  3 . In addition, since the fragile portions  73  are disposed uniformly in the Y direction on the respective side surfaces  66 , fixing of the metal cover  52  and the metal base  51  is stable. Then, it is possible to provide a gap for absorbing a dimensional error caused by a manufacturing error and the like between the metal base  51  and the fragile portions  73  since the fragile portions  73  are deformed to the metal base  51  side and fixed to the metal base  51 . As a result, when the metal cover  52  is fixed in the metal base  51 , it is possible to more easily insert the metal base  51  between the side surfaces  66 . 
     In addition, in the recording head  3  in the embodiment, since the circuit board  15  is disposed along the side surfaces  66  of the metal cover  52 , it is possible for heat that is generated in the circuit board  15  to escape to the metal cover  52 . Furthermore, since the flow path member  13  is fixed on the upper surface  65  of the metal cover  52 , it is possible to cool the metal cover  52  using liquid that flows along the flow path member inside the flow path member  13 . As a result, it is possible to more effectively perform heat dissipation of the circuit board  15 . 
     Note that, the shape of the fragile portions  73  is not limited to the shape in the first embodiment described above. In short, the fragile portions  73  may be any shape as long as the rigidity is lower than the upper surface  65  of the metal cover  52 . For example, the fragile portion  73  in the second embodiment that is shown in  FIGS. 10 and 11  does not extend further toward the inside than the side surface  66  in the X direction, and the lower end of the side surfaces  66  are aligned at substantially the same position. In detail, as shown in  FIGS. 10 and 11 , the fragile portion  73  in the embodiment consists of two arm portions  74  that extend from the cutout portion  88  toward the lower side of the side surface  66  and the fixed base portion  75  that is formed on the tip end of the two arm portions  74  and on which the through hole  71  is established. In addition, the side surfaces of both sides in the X direction of the metal base  51  in the embodiment is not formed in a concave portion, and are formed to be flat. Furthermore, the metal cover fixing screw hole  70  is formed at a position that corresponds to the fragile portion  73  on the side surface. Therefore, in a state in which the metal base  51  is inserted between both side surfaces  66  of the metal cover  52  and the fragile portion  73  is not fixed to the metal base  51 , the fragile portion  73  opens a slight gap between the side surfaces of the metal base  51  and extends along the side surfaces. Then, the fragile portion  73  slightly deforms inside, abuts with the side surfaces of the metal base  51  and is fixed to the metal base  51  by tightening the metal cover fixing screw  72  to the metal cover fixing screw hole  70  through the through hole  71  of the fragile portion  73 . Thereby, even in the embodiment, it is possible to suppress distortion of the metal base  51  while correcting distortion of the flow path member  13  using the upper surface  65  of the metal cover  52 . Note that, since other configurations are the same as the first embodiment described above, explanation is omitted. 
     In addition, the fragile portion  73  in a third embodiment shown in  FIGS. 12 and 13  is not provided with the arm portion  74 , and simply, a portion extends from the lower end of the side surface  66  of the metal cover  52 . The width of the fragile portion  73  (that is, the dimension in the Y direction) is formed to be as narrow as possible in a range that it is possible to establish the through hole  71 . Therefore, the fragile portion  73  in the embodiment is also able to have low rigidity in comparison to the other portion of the metal cover  52 . In addition, the side surfaces of both sides in the X direction of the metal base  51  in the embodiment is formed to be flat in the same manner as in the second embodiment described above. Therefore, in a state in which the metal base  51  is inserted between both side surfaces  66  of the metal cover  52  and the fragile portion  73  is not fixed to the metal base  51 , the fragile portion  73  opens a slight gap between the side surfaces of the metal base  51  and extends along the side surfaces. Then, even in the embodiment, the fragile portion  73  slightly changes shape inside, abuts with the side surfaces of the metal base  51  and is fixed to the metal base  51  by tightening the metal cover fixing screw  72  in the metal cover fixing screw hole  70  through the through hole  71  of the fragile portion  73 . Thereby, it is possible to suppress distortion of the metal base  51  while correcting distortion of the flow path member  13  using the upper surface  65  of the metal cover  52 . Note that, since other configurations are the same as the first embodiment described above, explanation is omitted. 
     Note that, in the each embodiment described above, the flow path member  13  is fixed to the metal cover  52 , but the invention is not limited thereto. For example, the flow path member may be attached to the upper portion of the pressure adjustment member inside the metal cover, and may be provided with a through hole into which a liquid supply tube and a gas supply tube are inserted into the metal cover. By doing this, for example, it is possible to fix an aggregated circuit board to the upper surface of the metal cover as one type of laminated member. Thereby, it is possible to correct distortion of the aggregated circuit board. As a result, connection is easy to the circuit board that is one type of connection member which is disposed below the aggregated circuit board by interposing the upper surface of the metal cover therebetween (in detail, one or a plurality of connectors that are provided on the circuit board). In addition, connection between the metal cover and the laminated member of the flow path member, the aggregated circuit board, or the like is not limited to so-called surface connection in which the upper surface of the metal cover and the lower surface of the laminated member abut. For example, a support pin may protrude to either one of the upper surface of the metal cover and the lower surface of the laminated member, and the support pin may be in so-called point contact abutting with the other of the upper surface of the metal cover and the lower surface of the laminated member. In addition, an intermediate member may be interposed between the metal cover and the laminated member, and the metal cover and the laminated member may be fixed. 
     In addition, in each embodiment described above, the recording head  3  is formed in a parallelogram shape in planar view, but is not limited thereto. For example, it is also possible to adopt a configuration in which the recording head is formed in a rectangular shape, a square shape, or another polygonal shape in planar view. In a case where the recording head is formed in the rectangular shape or the square shape in planar view, the metal cover and the metal base are formed in the rectangular shape or the square shape in planar view, and the positions are aligned in the longitudinal direction (Y direction) on both side surfaces of the metal cover. In addition, the fragile portion is formed to be symmetrical left and right with respect to a virtual line that passes through the center of the metal cover in a short direction (X direction). By doing this, it is possible for force that acts on the metal base caused by fixing of the fragile portion to be symmetrical left to right and to further suppress distortion of the metal base. 
     Furthermore, in each embodiment described above, a line head that is provided with a plurality of liquid ejecting units  4  is given as an example of the recording head  3 , but the invention is not limited thereto. It is also possible to apply the invention to a liquid ejecting head (so-called serial head) that performs discharge of ink while scanning (reciprocating movement) in the direction (Y direction) which is orthogonal to the transport direction of the recording medium. In such a liquid ejecting head, it is possible to adopt a configuration in which only one liquid ejecting unit is provided. In addition, in either of a line head and a serial head, the number of unit heads that configure the liquid ejecting unit may be one or more. In short, it is possible to apply the invention if a recording head is provided with the metal base to which the liquid ejecting unit is fixed that has one or more unit head and the metal cover that is attached to the metal base. In addition, it is possible to adopt the base member that consists of another member (for example, synthetic resin) as the base member not limited to the metal base  51  made from metal. Furthermore, it is possible to adopt the cover member that consists of another member (for example, synthetic resin) as the cover member not limited to the metal cover  52  made from metal. 
     In addition, the fragile portion  73  in the first embodiment and the second embodiment described above is provided with two arm portions  74 , but the invention is not limited thereto. One or more arm portions may be provided. In addition, it is possible to appropriately set the length (dimension in the Z direction) and the width (dimension in the Y direction) of the arm portion. For example, in a case where it is desirable to further weaken rigidity, it is possible to lengthen the length of the arm portion and narrow the width of the arm portion. Furthermore, the thickness of the fragile portion  73  in each embodiment described above is aligned with the thickness of the side surface  66 , but the invention is not limited thereto. For example, it is also possible to further weaken rigidity by making the thickness of the fragile portion thinner than the thickness of the side surface. 
     Then, above, the ink jet recording head  3  is described as an example of the liquid ejecting head, but the invention is also able to be applied to another liquid ejecting head that is provided with the cover member and the base member. For example, it is also possible to apply the invention to a color material ejecting head which is used in manufacture of a color filter of a liquid crystal display or the like, an electrode material ejecting head that is used in electrode formation such as an organic electro luminescence (EL) display, a field emission display (FED), or the like, a biological organic matter ejecting head which is used in manufacture biochips (bio-chemical element), and the like. A color material ejecting head for the display manufacturing apparatus ejects solution of each color material of red (R), green (G), and blue (B) as one type of liquid. In addition, an electrode material ejecting head for the electrode forming apparatus ejects electrode material in liquid form as one type of liquid, and a bio-organic material ejecting head for the chip manufacturing apparatus ejects a bio-organic material solution as one type of liquid.