JP2005053144A - Liquid jet head and liquid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet head wherein pressure generating chambers are arranged in high density and the head can be reduced in size, and a liquid jet device. <P>SOLUTION: Thin, long pressure generating chambers 12 are arranged to form opposing two rows of pressure generating chamber arrays in parallel to a direction of two rows of nozzle arrays. A piezoelectric element 300 is provided to each of the pressure generating chambers. A discrete electrode 80 forming the piezoelectric element is connected to a connection terminal section 91. The width of the connection terminal section 91 is smaller than that of the discrete electrode 80. The connection terminals provided to the respective pressure generating chambers belonging to one pressure generating chamber array are in parallel to the connection terminals provided to the respective pressure generating chambers belonging to the other pressure generating chamber array, and the parts of them are overlapped with each other in the direction of the nozzle array. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a liquid in which a part of a pressure generating chamber communicating with a nozzle opening for discharging droplets is configured by a diaphragm, and a piezoelectric element is provided through the diaphragm, and droplets are discharged by displacement of the piezoelectric element. More particularly, the present invention relates to an ink jet recording head and an ink jet recording apparatus that eject ink as a liquid.

  A part of the pressure generation chamber communicating with the nozzle opening for discharging ink droplets is constituted by a vibration plate, and the vibration plate is deformed by a piezoelectric element to pressurize the ink in the pressure generation chamber to discharge ink droplets from the nozzle opening. Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that extends and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator.

  The former can change the volume of the pressure generation chamber by bringing the end face of the piezoelectric element into contact with the vibration plate, and it is possible to manufacture a head suitable for high-density printing, while the piezoelectric element is arranged in an array of nozzle openings. There is a problem that the manufacturing process is complicated because a difficult process of matching the pitch into a comb-like shape and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are necessary.

  On the other hand, the latter can flexibly vibrate, although a piezoelectric element can be built on the diaphragm by a relatively simple process of sticking a green sheet of piezoelectric material according to the shape of the pressure generation chamber and firing it. There is a problem that a certain amount of area is required for the use of, and high-density arrangement is difficult.

  On the other hand, in order to eliminate the disadvantages of the latter recording head, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique, and this piezoelectric material layer is shaped to correspond to the pressure generating chamber by lithography. There is proposed a structure in which a piezoelectric element is formed so as to be separated for each pressure generating chamber (see, for example, Patent Document 1).

  As such an ink jet recording head, a flow path forming substrate having at least two rows of pressure generating chambers communicating with nozzle openings, and a piezoelectric element bonded to the flow path forming substrate and driving the piezoelectric element. A structure is known in which a driving circuit is mounted on a bonding substrate, and the driving circuit and each piezoelectric element are electrically connected via a through-hole provided in the bonding substrate (for example, Patent Documents). 2).

Specifically, in such an ink jet recording head, as shown in FIG. 16, two rows of piezoelectric elements 202 are provided in a region corresponding to the row of pressure generation chambers 201. Each piezoelectric element 202 extends from a region facing the pressure generation chamber 201 to the peripheral wall on the reservoir 203 side, and is sandwiched between a flow path forming substrate 204 and a reservoir forming substrate (bonding substrate) 205. ing. Furthermore, a through-hole 206 is provided for each row of the pressure generation chambers 201 on the reservoir 203 side of the reservoir forming substrate 205, that is, in a region facing the peripheral wall of the pressure generation chamber 201. The drive circuit 207 and each piezoelectric element 202 mounted in a substantially central portion of the reservoir forming substrate 205, that is, in a region corresponding to between the rows of the piezoelectric elements 202, are through holes provided on both sides of the drive circuit 207. They are electrically connected by a bonding wire 208 through 206.
Japanese Patent Laid-Open No. 5-286131 (FIG. 3, paragraph [0013]) JP 2000-296616 A (FIG. 20, paragraphs [0161] to [0163])

  However, the conventional ink jet recording head has a structure in which two rows of piezoelectric elements are driven by one drive circuit, so that the manufacturing cost can be kept relatively low. However, through holes are formed on both sides of the drive circuit, respectively. Therefore, it is necessary to make the flow path forming substrate and the bonding substrate relatively large, and there is a problem that it is difficult to reduce the size of the head.

  In particular, if the pressure generating chambers are arranged at high density to reduce the size of the head, there is a problem that it is difficult to secure a region for forming a plurality of through holes.

  Such a problem occurs not only in an ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject liquid other than ink.

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus in which pressure generating chambers are arranged at high density and the size can be reduced.

  The present invention provides a flow path forming substrate having a plurality of pressure generating chambers that communicate with each nozzle opening of a nozzle row and sealed by a diaphragm, and the plurality of pressure generators provided on the diaphragm. A liquid ejecting head comprising: a plurality of pressure changing means for changing the pressure of the liquid supplied to each of the chambers and discharging the liquid from the corresponding nozzle openings, , Two opposing pressure generation chamber rows parallel to the direction of the nozzle row are formed, and each pressure variation means is composed of a piezoelectric element having a common electrode, a piezoelectric layer, and an individual electrode. The individual electrodes are extended to the intermediate region sandwiched between the opposing pressure generation chamber rows, and are connected to one side in the width direction on the connection terminal portion formed narrower than the width of the individual electrodes of the piezoelectric element. Connected only by The connection terminal portion connected to the individual electrode of each piezoelectric element provided corresponding to each pressure generation chamber belonging to one pressure generation chamber row, and provided corresponding to each pressure generation chamber belonging to the other pressure generation chamber row The connection terminal portion connected to the individual electrode of each piezoelectric element is a liquid ejecting head characterized by having regions that are parallel to each other and overlap in the direction of the nozzle row.

  Wiring for driving the piezoelectric layer is soldered to the connection terminal portion that is electrically connected to the individual electrode of each piezoelectric element. For the convenience of the soldering operation, the connection terminal portion needs to have a predetermined length. That is, the connection terminal portion connected to the individual electrode of each piezoelectric element provided corresponding to each pressure generation chamber belonging to one pressure generation chamber row also corresponds to each pressure generation chamber belonging to the other pressure generation chamber row The connection terminal portions connected to the individual electrodes of the piezoelectric elements provided in this way also need to have a predetermined length. In the present invention, the connection terminal portion has a portion overlapping in the direction of the nozzle row, thereby realizing a reduction in the size of the head in the longitudinal direction of the piezoelectric element.

  Preferably, the width of the connection terminal portion is ½ or less of the width of the individual electrode. In this case, the arrangement density of the connection terminals is twice or more the arrangement density of the pressure generating chambers, which can be sufficiently realized by the current manufacturing technology. Specifically, the arrangement density of the connection terminal portions overlapping in the nozzle row direction can be 240 dots / inch (dpi) or more.

  Considering the effect of reducing the size of the head, the length of the overlapping portion of the connection terminal portion in the direction of the nozzle row is preferably longer. Specifically, it is preferable that it is 1/2 or more of the entire length of the connection terminal portion.

  Further, it is preferable that positioning reference holes are formed in the flow path forming substrate at positions outside the two nozzle rows and the two pressure generation chamber rows. In particular, the vertical reference holes and the horizontal reference holes of the planar nozzle plate and the flow path forming substrate are outside the vicinity of the midpoint of each side of the rectangle or rhombus formed by the two rows of pressure generation chambers. Are preferably provided respectively. One of the reference holes is circular and the other is a long hole.

  The present invention also includes a liquid ejecting head having any one of the above characteristics, and a liquid supply mechanism that supplies the liquid to each of the plurality of pressure generating chambers. Device.

  According to the present invention, a downsized liquid ejecting apparatus can be realized by downsizing the liquid ejecting head.

  According to the present invention, the connection terminal portion has a portion that overlaps in the direction of the nozzle row, so that the size of the head in the longitudinal direction of the piezoelectric element can be reduced.

Hereinafter, the present invention will be described in detail based on embodiments.
FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of FIG. As shown in the drawing, the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110) in this embodiment. One surface of the flow path forming substrate 10 is an opening surface, and an elastic film 50 (vibration plate) having a thickness of 1 to 2 μm made of silicon dioxide previously formed by thermal oxidation is formed on the other surface.

  On the other hand, pressure generation chambers 12 partitioned by a plurality of partition walls 11 are arranged in parallel in the width direction on the opening surface of the flow path forming substrate 10 by anisotropic etching of the silicon single crystal substrate. On the outer side in the direction, there is formed a communication portion 13 that forms part of the reservoir 100 that communicates with a reservoir portion 31 of a reservoir forming substrate 30 to be described later and serves as a common ink chamber for each pressure generating chamber 12. 12 communicated with one end portion in the longitudinal direction via an ink supply path 14.

  Here, the anisotropic etching is performed by utilizing the difference in etching rate of the silicon single crystal substrate. For example, in this embodiment, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, the first (111) plane perpendicular to the (110) plane is gradually eroded, and the first (111) plane. And a second (111) plane that forms an angle of about 70 degrees with the (110) plane and an angle of about 35 degrees appears, and the (111) plane is compared with the etching rate of the (110) plane. This is performed using the property that the etching rate is about 1/180. By this anisotropic etching, precision processing can be performed based on the parallelogram depth processing formed by two first (111) surfaces and two oblique second (111) surfaces. The pressure generating chambers 12 can be arranged with high density.

  In the present embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane and the short side is formed by the second (111) plane. The pressure generation chamber 12 is formed by etching until it substantially passes through the flow path forming substrate 10 and reaches the elastic film 50. Here, the amount of the elastic film 50 that is affected by the alkaline solution for etching the silicon single crystal substrate is extremely small. In addition, each ink supply path 14 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and the flow path resistance of the ink flowing into the pressure generation chamber 12 is kept constant. That is, the ink supply path 14 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). Half etching is performed by adjusting the etching time.

  As the thickness of the flow path forming substrate 10, an optimum thickness may be selected in accordance with the arrangement density of the pressure generating chambers 12. The arrangement density of the pressure generating chambers 12 is, for example, 120 to 150 dpi.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], glass ceramics, silicon It consists of a single crystal substrate or non-rust steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate that is the flow path forming substrate 10 from impact and external force. Further, the nozzle plate 20 may be formed of a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10. In this case, since the deformation by heat of the flow path forming substrate 10 and the nozzle plate 20 is substantially the same, it can be easily joined using a thermosetting adhesive or the like. The nozzle opening may be provided directly on the flow path forming substrate 10.

  Here, the size of the pressure generation chamber 12 that applies ink droplet discharge pressure to the ink and the size of the nozzle opening 21 that discharges the ink droplet are optimized according to the amount of ink droplet to be discharged, the discharge speed, and the discharge frequency. The For example, when recording 360 ink droplets per inch, the nozzle opening 21 needs to be accurately formed with a diameter of several tens of μm.

  On the other hand, on the elastic film 50 opposite to the opening surface of the flow path forming substrate 10, a lower electrode film 60 having a thickness of, for example, about 0.2 μm and a piezoelectric film having a thickness of, for example, about 1.0 μm. The body layer 70 and the upper electrode film 80 having a thickness of, for example, about 0.05 μm are laminated and formed by a process described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber. Here, the piezoelectric element 300 and the diaphragm (elastic film 50) that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

  Further, in such a piezoelectric element 300, a lead electrode 90 (a part of the upper electrode) made of, for example, gold (Au) or the like for connection with the drive circuit 110 is formed as a lead-out wiring. Each lead electrode 90 extends from the vicinity of the end portion of each pressure generating chamber 12 of the upper electrode film 80 to the elastic film 50. The width of each lead electrode is narrower than the width of the upper electrode film 80. Each lead electrode 90 is connected to a connection terminal portion 91 extending to a region facing the through hole 33 of the reservoir forming substrate 30, and the connection terminal portion 91 and the drive circuit 110 pass through the through hole 33. They are electrically connected by a connection wiring 120 extending through them.

  Here, the width of the connection terminal portion 91 is narrower than the width of each lead electrode 90 and is ½ of the width of the upper electrode film 80. The lead electrode 90 connected to the upper electrode film 80 of each piezoelectric element 300 provided corresponding to each pressure generating chamber 12 belonging to one pressure generating chamber row (for example, the left side in FIG. 2) Only a part on one side in the width direction (the lower side in FIG. 2) is connected to the connection terminal portion 91. On the contrary, the lead electrode 90 connected to the upper electrode film 80 of each piezoelectric element 300 provided corresponding to each pressure generating chamber 12 belonging to the other pressure generating chamber row (right side in FIG. 2) Only a part on the other side in the width direction (upper side in FIG. 2) is connected to the connection terminal portion 91.

  An important feature of the present embodiment is that the upper electrode film 80 of each piezoelectric element provided corresponding to each pressure generating chamber 12 belonging to one pressure generating chamber row (for example, the left side in FIG. 2) is provided. Connection terminal 91 connected and connection connected to the other upper electrode film 80 of each piezoelectric element provided corresponding to each pressure generation chamber 12 belonging to the other pressure generation chamber row (right side in FIG. 2) The terminal portions 91 are parallel to each other and have portions that overlap in the nozzle row direction.

  In the case of the present embodiment, the arrangement density of all the connection terminal portions 91 is twice the arrangement density of the pressure generating chambers 12. Further, the length of the portion of the connection terminal portion 91 that overlaps in the nozzle row direction is ½ or more of the total length of each connection terminal portion 91.

  A wiring for driving the piezoelectric layer 70 is soldered to each connection terminal portion 91. For the convenience of the soldering operation, the connection terminal portion 91 needs to have a predetermined length. In this embodiment, the connection terminal portion 91 has a portion that overlaps in the direction of the nozzle row. Thus, the size of the head in the longitudinal direction of the piezoelectric element 300 is reduced.

  Further, in the present embodiment, a reservoir forming substrate 30 that is a bonding substrate having a reservoir portion 31 constituting at least a part of the reservoir 100 is bonded onto the flow path forming substrate 10 on which such a piezoelectric element 300 is formed. Has been. In this embodiment, the reservoir portion 31 is formed across the reservoir forming substrate 30 in the thickness direction and across the width direction of the pressure generating chamber 12, and as described above, the communication portion of the flow path forming substrate 10 is formed. The reservoir 100 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12.

  Further, in the region facing the piezoelectric element 300 of the reservoir forming substrate 30, a piezoelectric element holding portion 32 capable of sealing the space is secured in a state where a space that does not hinder the movement of the piezoelectric element 300 is secured. The piezoelectric element 300 is sealed in each piezoelectric element holding portion 32. In the present embodiment, the piezoelectric element holding portion 32 is provided for each row of the piezoelectric elements 300. However, of course, the piezoelectric element holding portion 32 may be provided independently for each piezoelectric element 300. . Examples of such a reservoir forming substrate 30 include glass, ceramics, metal, and plastic, but it is more preferable to use a material that is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. It is preferable to use a ceramic material or the like, and in this embodiment, a ceramic single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  In addition, a through hole 33 that penetrates the reservoir forming substrate 30 in the thickness direction is provided in a substantially central portion of the reservoir forming substrate 30, that is, a region facing between the rows of the pressure generating chambers 12. As described above, the connection terminal portion 91 connected to the lead electrode 90 (part of the upper electrode) extending from each piezoelectric element 300 is extended to the region facing the through hole 33 and exposed. Has been.

  Further, for example, a circuit board or a semiconductor integrated circuit (IC) for driving each piezoelectric element 300 is provided on both sides of the through hole 33 of the reservoir forming substrate 30, that is, on a portion corresponding to each row of the pressure generating chambers 12. ) And the like are mounted. For example, in the present embodiment, each drive circuit 110 mounted on both sides of the through-hole 33 is for driving the piezoelectric element 300 provided in a region facing each drive circuit 110. And each drive circuit 110 and each connection terminal part 91 are each electrically connected by the connection wiring 120 which was extended through the through-hole 33 and which consists of conductive wires, such as a bonding wire, for example. (Refer FIG.2 (b)).

  As described above, in the present embodiment, one through hole 33 is provided in a region facing between the rows of the pressure generating chambers 12 of the reservoir forming substrate 30, and each connection wiring 120 extending through the through hole 33 is used to connect each through hole 33. Since the connection terminal portion 91 and the drive circuit 110 are electrically connected, the area where the through hole 33 of the reservoir forming substrate 30 is formed can be reduced. That is, the ratio of the through holes 33 to the entire surface of the reservoir forming substrate 30 can be reduced. Moreover, since the drive circuit 110 and each connection terminal part 91 are electrically connected through one through-hole 33, manufacturing efficiency can be improved. Therefore, even if the pressure generating chambers 12 are arranged at a relatively high density, the through holes 33 can be formed without increasing the size of the flow path forming substrate 10 and the reservoir forming substrate 30, thereby improving the printing quality and reducing the size. Thus, an ink jet recording head can be realized.

  Further, since the connection terminal portions 91 extending like comb teeth from each of the two rows of pressure generation chambers are formed so as to overlap in the direction of the nozzle row, the head in the longitudinal direction of the piezoelectric element 300 can be reduced in size. Has been.

  In the present embodiment, the two drive circuits 110 are mounted on both sides of the through hole 33 of the reservoir forming substrate 30, respectively. However, the number of the drive circuits 110 is not particularly limited. One drive circuit having a communication hole communicating with the hole may be mounted. Of course, three or more drive circuits may be mounted. Further, the number of through holes is not limited to one. Of course, two or more through holes may be provided as long as the ratio of the through holes to the entire surface of the reservoir forming substrate can be reduced.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the reservoir forming substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Thus, the flexible portion 35 can be deformed by a change in internal pressure. An ink introduction port 44 for supplying ink to the reservoir 100 is formed on the compliance substrate 40 on the outer side of the central portion of the reservoir 100 in the longitudinal direction. Further, the reservoir forming substrate 30 is provided with an ink introduction path 34 that communicates the ink introduction port 44 with the sidewall of the reservoir 100.

  In such an ink jet recording head of this embodiment, ink is taken in from an ink introduction port 44 connected to an external ink supply means (not shown), and the interior is filled with ink from the reservoir 100 to the nozzle opening 21. In accordance with the recording signal from 110, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed. By doing so, the pressure in each pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

  Here, an example of the manufacturing method of the ink jet recording head of the present embodiment described above will be described with reference to FIGS. 3 to 5 are cross-sectional views showing a part of the pressure generating chamber 12 in the longitudinal direction. First, as shown in FIG. 3A, an elastic film 50 made of silicon dioxide is formed by thermally oxidizing a silicon single crystal substrate wafer to be the flow path forming substrate 10 in a diffusion furnace at about 1100 ° C. Next, as shown in FIG. 3B, after forming the lower electrode film 60 on the entire surface of the elastic film 50 by sputtering, the entire pattern of the lower electrode film 60 is formed by patterning. As a material of the lower electrode film 60, platinum (Pt) or the like is suitable. This is because a piezoelectric layer 70 described later formed by sputtering or sol-gel method needs to be crystallized by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere, particularly when lead zirconate titanate (PZT) is used as the piezoelectric layer 70. It is desirable that the change in conductivity due to diffusion of lead oxide is small, and platinum is preferable for these reasons.

  Next, as shown in FIG. 3C, a piezoelectric layer 70 is formed. The piezoelectric layer 70 preferably has crystals oriented. For example, in the present embodiment, a so-called sol-gel method is obtained in which a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied and dried to be gelled, and further baked at a high temperature to obtain a piezoelectric layer 70 made of a metal oxide. Is used. Thereby, the piezoelectric layer 70 in which the crystals are oriented is obtained. As a material of the piezoelectric layer 70, a lead zirconate titanate-based material is suitable when used for an ink jet recording head. In addition, the film-forming method of this piezoelectric material layer 70 is not specifically limited, For example, you may form by sputtering method. Furthermore, after forming a lead zirconate titanate precursor film by a sol-gel method or a sputtering method, a method of crystal growth at a low temperature by a high-pressure treatment method in an alkaline aqueous solution may be used.

  In any case, the piezoelectric layer 70 thus formed has crystals preferentially oriented unlike a bulk piezoelectric body. Furthermore, in the present embodiment, the piezoelectric layer 70 has crystals formed in a columnar shape. Note that the preferential orientation refers to a state in which the orientation direction of the crystal is not disordered and a specific crystal plane is oriented in a substantially constant direction. A columnar thin film refers to a state in which substantially cylindrical crystals are aggregated over the surface direction with the central axis substantially coincided with the thickness direction to form a thin film. Of course, it may be a thin film formed of preferentially oriented granular crystals. Note that the thickness of the piezoelectric layer manufactured in this way in the thin film process is generally 0.2 to 5 μm.

  Next, as shown in FIG. 3D, an upper electrode film 80 is formed. The upper electrode film 80 only needs to be a highly conductive material, and many metals such as aluminum, gold, nickel, and platinum, conductive oxides, and the like can be used. In this embodiment, the platinum film is formed by sputtering.

  Next, as shown in FIG. 4A, the piezoelectric element 300 is patterned by etching only the piezoelectric layer 70 and the upper electrode film 80. Next, as shown in FIG. 4B, lead electrodes 90 and connection terminal portions 91 are formed. Specifically, for example, lead electrodes 90 and connection terminal portions 91 made of, for example, gold (Au) are formed over the entire surface of the flow path forming substrate 10 and patterned for each piezoelectric element 300. The above is the film forming process.

  After the film is formed in this way, the above-described anisotropic etching of the silicon single crystal substrate with the alkaline solution is performed, and as shown in FIG. 4C, the pressure generating chamber 12, the communication portion 13, and the ink supply path 14 etc. are formed.

  Next, as shown in FIG. 5A, the reservoir forming substrate 30 and the flow path forming substrate 10 are joined. At this time, the reservoir forming substrate 30 is bonded to the flow path forming substrate 10 with each connection terminal portion 91 protruding into the through hole 33 by a predetermined amount. Subsequently, as shown in FIG. 5B, the nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate 10 opposite to the reservoir forming substrate 30 is joined, and the reservoir forming substrate 30. The compliance substrate 40 is bonded on top. Thereafter, as shown in FIG. 5C, the drive circuits 110 for driving the piezoelectric elements 300 are mounted on the reservoir forming substrates 30 on both sides of the through-hole 33. Then, for example, the connection wiring 120 is formed by wire bonding or the like, and each drive circuit 110 and each connection terminal portion 91 are electrically connected. Thereby, an ink jet recording head is manufactured.

  In practice, a large number of chips are simultaneously formed on a single wafer by the above-described series of film formation and anisotropic etching, and after the process is completed, a single chip-sized flow path is formed as shown in FIG. Divide each substrate 10. Then, the reservoir forming substrate 30 and the compliance substrate 40 are sequentially bonded and integrated with the divided flow path forming substrate 10 to form an ink jet recording head.

  While the embodiments of the present invention have been described above, the basic configuration of the ink jet recording head is not limited to that described above. For example, in the above-described embodiment, the thin film type ink jet recording head manufactured by applying the film forming and lithography process is taken as an example. However, the present invention is not limited to this. For example, a green sheet is pasted. The present invention can also be applied to a thick film type ink jet recording head formed by such a method.

  In addition, the ink jet recording heads of these embodiments constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are mounted on the ink jet recording apparatus. FIG. 6 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 6, in the recording head units 1A and 1B having the ink jet recording head, cartridges 2A and 2B constituting ink supply means are detachably provided, and a carriage 3 on which the recording head units 1A and 1B are mounted. Is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  Furthermore, since the present invention can be applied to the following second embodiment, the mode will be described.

  As shown in FIG. 7, the flow path unit 502 of the present embodiment includes an ink supply port 505 that functions as an orifice, a supply port forming substrate 507 that has a through hole that is a part of the nozzle communication port 506, and a common ink chamber. An ink chamber forming substrate 509 having a through hole 508 and a through hole serving as a part of the nozzle communication port 506, and a nozzle plate 511 having nozzle openings 510... Opened along the sub-scanning direction. The supply port forming substrate 507, the ink chamber forming substrate 509, and the nozzle plate 511 are produced, for example, by pressing a stainless plate.

  In FIG. 7, a part of the flow path unit 502 corresponding to one actuator unit 503 is shown. In this embodiment, since three actuator units 503... Are joined to one flow path unit 502, the ink supply port 505, the nozzle communication port 506, the supply port forming substrate 507, the common ink chamber 508, etc. A total of three sets are formed for each unit 503.

  The flow path unit 502 includes a nozzle plate 511 disposed on one surface (lower side in the drawing) of the ink chamber forming substrate 509 and a supply port forming substrate 507 disposed on the other surface (upper side), respectively. It is manufactured by bonding the mouth forming substrate 507, the ink chamber forming substrate 509, and the nozzle plate 511. For example, the members 507, 509, and 511 are manufactured by bonding them with a sheet-like adhesive.

  As shown in FIG. 8, the nozzle openings 510 are formed in a plurality of rows at a predetermined pitch. A nozzle row 512 is constituted by the plurality of nozzle openings 510. For example, one nozzle row 512 is constituted by 92 nozzle openings 510. Further, two nozzle rows 512 are formed for one actuator unit 503. Therefore, in this embodiment, a total of six nozzle rows 512... Are formed side by side in one flow path unit 502.

  The actuator unit 503 is also called a head chip and is a kind of piezoelectric actuator. As shown in FIG. 7, the actuator unit 503 includes a pressure chamber forming substrate 514 having a through hole serving as a pressure chamber 513, a diaphragm 515 that defines a part of the pressure chamber 513, a supply side communication port 516, And a lid member 517 having a through hole that is a part of the nozzle communication port 506 and a piezoelectric vibrator 518 (piezoelectric element). Regarding the plate thickness of each of these members, the pressure chamber forming substrate 514 and the lid member 517 are preferably 50 μm or more, more preferably 100 μm or more. Moreover, the diaphragm 515 is preferably 50 μm or less, more preferably about 3 to 12 μm.

  The actuator unit 503 is manufactured by arranging a lid member 517 on one surface of the pressure chamber forming substrate 514 and a diaphragm 515 on the other surface, and integrating these members. That is, the pressure chamber forming substrate 514, the vibration plate 515, and the lid member 517 are made of ceramics such as alumina and zirconium oxide, and are integrated by firing.

  For example, a green sheet (unfired sheet material) is subjected to processing such as cutting and punching to form necessary through holes and the like, and each sheet of the pressure chamber forming substrate 514, the vibration plate 515, and the lid member 517 A precursor is formed. Then, by laminating and firing the respective sheet precursors, the respective sheet precursors are integrated into one ceramic sheet. In this case, since each sheet-like precursor is integrally fired, no special bonding treatment is required. Moreover, high sealing performance can be obtained at the joint surface of each sheet-like precursor.

  A single ceramic sheet has a plurality of units of pressure chambers 513, nozzle communication ports 506, and the like. In other words, a plurality of actuator units 503 (head chips)... Are produced from one ceramic sheet. For example, a plurality of chip regions to be one actuator unit 503 are set in a matrix in one ceramic sheet. Then, after forming necessary members such as the piezoelectric vibrator 518 in each chip region, the ceramic sheet is cut into each chip region, thereby obtaining a plurality of actuator units 503.

  The pressure chamber 513 is a hollow portion that is elongated in a direction perpendicular to the nozzle row 512, and a plurality of the pressure chambers 513 are formed corresponding to the nozzle openings 510. That is, as shown in FIG. 8, they are arranged in the nozzle row direction. One end of each pressure chamber 513 communicates with the common ink chamber 508 through the supply side communication port 516 and the ink supply port 505. Further, the other end of the pressure chamber 513 opposite to the supply side communication port 516 communicates with the corresponding nozzle opening 510 through the nozzle communication port 506. Further, a part (upper surface) of the pressure chamber 513 is partitioned by a diaphragm 515.

  The piezoelectric vibrator 518 is a so-called flexural vibration mode piezoelectric vibrator 518, and is formed for each pressure chamber 13 on the surface of the diaphragm opposite to the pressure chamber 513. The piezoelectric vibrator 518 has a block shape elongated in the longitudinal direction of the pressure chamber, and its width is substantially equal to the width of the pressure chamber 513, and its length is slightly longer than the length of the pressure chamber 513. Further, the piezoelectric vibrator 518 is disposed so that both end portions thereof exceed the longitudinal end portion of the pressure chamber 513.

  As shown in FIG. 9, the piezoelectric vibrator 518 is provided for each pressure chamber 513 on the vibration plate surface opposite to the pressure chamber 513. That is, the piezoelectric vibrators 518 are arranged in the nozzle row direction. Among these piezoelectric vibrators 518, the one located at the end of the vibrator row is a dummy vibrator 518a that does not participate in ejection of ink droplets (that is, does not deform without being supplied with a drive signal). A plurality of piezoelectric vibrators 518 other than the dummy vibrators 518a function as drive vibrators 518b involved in ink droplet ejection (that is, deformed by supplying a drive signal).

  Further, individual terminals (connection terminal portions) 519 are provided for each piezoelectric vibrator 518 on one side in the longitudinal direction of the piezoelectric vibrator 518 (drive vibrator 518b, dummy vibrator 518a). The individual terminal 519 is a portion through which the contact terminal 520 (see FIG. 12) of the wiring board 504 described above is conducted. Further, on the other side in the longitudinal direction of the piezoelectric vibrator 518, a linear common trunk electrode 521 constituting a part of the common electrode is extended in the nozzle row direction.

  As shown in FIG. 10, the piezoelectric vibrator 518 (drive vibrator 518b) in the present embodiment has a multilayer structure including a piezoelectric layer 522, a common branch electrode 523, a drive electrode (individual electrode) 524, and the like. Two piezoelectric layers 522 are sandwiched between the drive electrode 524 and the common branch electrode 523. A drive signal supply source (not shown) is connected to the drive electrode 524 through the individual terminal 519, and the common branch electrode 523 is adjusted to, for example, the ground potential through the common trunk electrode 521 and the like. When a drive signal is supplied to the drive electrode 524, an electric field having a strength corresponding to the potential difference is generated between the drive electrode 524 and the common branch electrode 523. This electric field is applied to the piezoelectric layer 522, and the piezoelectric layer 522 is deformed according to the strength of the electric field.

  That is, as the potential of the drive electrode 524 is increased, the piezoelectric layer 522 contracts in a direction orthogonal to the electric field, and the diaphragm 515 is deformed so that the volume of the pressure chamber 513 is reduced. On the other hand, as the potential of the drive electrode 524 is lowered, the piezoelectric layer 522 expands in a direction orthogonal to the electric field, and the diaphragm 515 is deformed so as to increase the volume of the pressure chamber 513.

  The actuator unit 503 and the flow path unit 502 are joined to each other. For example, a sheet-like adhesive is interposed between the supply port forming substrate 507 and the lid member 517, and in this state, the actuator unit 503 is pressed to the flow path unit 502 side to be bonded.

  The recording head 501 configured as described above has a series of ink flow paths from the common ink chamber 508 to the nozzle openings 510 through the ink supply ports 505, the supply side communication ports 516, the pressure chambers 513, and the nozzle communication ports 506. Is formed. During use, the ink flow path is filled with ink. When the piezoelectric vibrator 518 is deformed, the corresponding pressure chamber 513 contracts or expands, and pressure fluctuation occurs in the ink in the pressure chamber 513. By controlling the ink pressure, ink droplets can be ejected from the nozzle openings 510. For example, when the pressure chamber 513 having a constant volume is once expanded and then rapidly contracted, ink is filled with the expansion of the pressure chamber 513, and the ink in the pressure chamber 513 is pressurized by the subsequent rapid contraction. Ink droplets are ejected. Further, when ink droplets are ejected from the nozzle openings 510, new ink is supplied from the common ink chamber 508 into the ink flow path, so that ink droplets can be ejected continuously.

  Here, for high-speed recording, it is necessary to eject more ink droplets in a short time. In order to meet this requirement, it is necessary to consider the compliance of the diaphragm 515 in the portion defining the pressure chamber 513 and the deformation amount of the piezoelectric vibrator 518. That is, as the compliance of the diaphragm 515 increases, the response to deformation becomes worse and driving at a high frequency becomes difficult. Further, the smaller the compliance of the vibration plate 515, the harder the deformation of the vibration plate 515, and the smaller the amount of contraction of the pressure chamber 513, the smaller the amount of ink per drop.

  In this embodiment, the compliance of the vibration plate 515 is reduced by using the piezoelectric vibrator 518 having a multilayer structure, and a necessary amount of ink droplets can be ejected at a higher frequency than in the past. Further, the end portion of the individual terminal 519 is formed in a stacked state on the piezoelectric vibrator 518 to reduce the size in the width direction of the actuator unit 503. Further, in the present embodiment, as shown in FIG. 9, the width of the individual terminal 519 is formed to be about 1/3 of the width of the drive electrode 524, and one of the opposing pressure chamber rows (for example, the left side of FIG. 9). The individual terminals 519 of the piezoelectric vibrators 518 provided corresponding to the pressure chambers 513 belonging to) are connected to only a part of one side (upper side in FIG. 9) in the width direction of the drive electrode 24 and face each other. The individual terminal 519 of the piezoelectric vibrator 518 provided corresponding to each pressure chamber 513 belonging to the other of the chamber rows (right side in FIG. 9) is on the other side in the width direction of the drive electrode 24 (lower side in FIG. 9). Only partly connected. An important feature of the present embodiment is that the individual terminals connected to the piezoelectric vibrators 518 provided corresponding to the pressure chambers 513 belonging to one pressure chamber row (for example, the left side in FIG. 9). 519 and an individual terminal 519 connected to each piezoelectric vibrator 518 provided corresponding to each pressure chamber 513 belonging to the other pressure chamber row (right side in FIG. 9) are parallel to each other, and the nozzle row It has a part which overlaps in the direction of. Thereby, further downsizing is achieved in the width direction of the actuator unit 503.

  In the case of this embodiment, the arrangement pitch of the individual terminals 519 is three times the arrangement pitch of the pressure chambers 513. Further, the length of the portion of the individual terminal 519 that overlaps in the nozzle row direction is ½ or more of the total length of each individual terminal 519.

  In addition, a conductive electrode for conducting the common trunk electrode 521 and the individual electrode 519 is provided inside the dummy vibrator 518a. Hereinafter, these points will be described.

  First, the structure of the drive vibrator 518b will be described. As shown in FIG. 10, the piezoelectric layer 522 is composed of an upper layer piezoelectric body (outer piezoelectric body) 531 and a lower layer piezoelectric body (inner piezoelectric body) 532 which are formed in a block shape elongated in the longitudinal direction of the pressure chamber, and are stacked on each other. Is done. The common branch electrode 523 includes a common upper electrode (common outer electrode) 533 and a common lower electrode (common inner electrode) 534. The common branch electrode 523 and the drive electrode 524 constitute an electrode layer.

  Here, “upper (outer)” or “lower (inner)” indicates a positional relationship based on the diaphragm 515. That is, “upper (outer)” indicates the side far from the diaphragm 515, and “lower (inner)” indicates the side closer to the diaphragm 515.

  The drive electrode 524 is formed at the boundary between the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532. The common lower electrode 534 and the common upper electrode 533 constitute a common electrode together with the common trunk electrode 521. That is, this common electrode is formed in a comb-like shape in which a plurality of common branch electrodes 523 (common lower electrode 534, common upper electrode 533).

  The common lower electrode 534 is formed between the lower layer piezoelectric body 532 and the diaphragm 515, and the common upper electrode 533 is formed on the surface of the upper layer piezoelectric body 531 opposite to the lower layer piezoelectric body 532. That is, the drive vibrator 518b has a multilayer structure in which the common lower electrode 534, the lower layer piezoelectric body 532, the drive electrode 524, the upper layer piezoelectric body 531, and the common upper electrode 533 are stacked in this order from the vibration plate 515 side.

  In this embodiment, the thickness of the piezoelectric layer 522 is about 17 μm in total of the two layers of the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532, and the entire thickness of the piezoelectric vibrator 518 including the common branch electrode 523. Is about 20 μm. The conventional single-layer piezoelectric vibrator 518 has a thickness of the whole vibrator of about 15 μm. Accordingly, since the thickness of the piezoelectric vibrator 518 is increased, the compliance of the vibration plate 515 is reduced accordingly.

  The common upper electrode 533 and the common lower electrode 534 are adjusted to a constant potential, for example, a ground potential regardless of the drive signal. The drive electrode 524 changes the potential according to the supplied drive signal. Therefore, by supplying the drive signal, electric fields having opposite directions are generated between the drive electrode 524 and the common upper electrode 533 and between the drive electrode 524 and the common lower electrode 534, respectively.

  And as materials constituting these electrodes, for example, various conductors such as simple metals, alloys, and mixtures of electrically insulating ceramics and metals are selected, but defects such as alteration are not caused at the firing temperature. Is required. In this embodiment, gold is used for the common upper electrode 533, and platinum is used for the common lower electrode 534 and the drive electrode 524.

  Both the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532 are made of, for example, a piezoelectric material mainly composed of lead zirconate titanate (PZT). The upper layer piezoelectric body 531 and the lower layer piezoelectric body 532 have opposite polarization directions. For this reason, the expansion / contraction directions at the time of applying the drive signal are the same in the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532, and can be deformed without hindrance. That is, the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532 deform the diaphragm 515 so that the volume of the pressure chamber 513 decreases as the potential of the drive electrode 524 increases, and the potential of the drive electrode 524 decreases. The diaphragm 515 is deformed so as to increase the volume of the pressure chamber 513.

  Next, the structure on one side (the intermediate region side of two opposing pressure chamber rows) in the drive vibrator 518b will be described.

  As described above, the individual terminal 519 is formed on this one side. The individual terminal 519 of the drive vibrator 518b is a drive potential supply terminal to which a drive signal (drive potential) is supplied, and is electrically connected to a contact terminal 520 (see FIG. 12) of the wiring board 504 that is overlaid on the upper surface of the actuator unit 503. The The individual terminal 519 is electrically connected to a drive electrode 524 extending in the longitudinal direction of the pressure chamber. That is, a part of the individual terminal 519 is provided in a laminated state on the end of the drive electrode 524.

In the present embodiment, the end of the individual terminal 519 is formed so as to overlap the surface of the vibrator end (upper piezoelectric body) that does not overlap the pressure chamber 513. Further, the individual terminal 519 is formed apart from the common upper electrode 533 (common branch electrode 523).
That is, as shown in FIGS. 11 and 12, one end of the piezoelectric vibrator 518 exceeds the end of the pressure chamber 513, in other words, a non-overlapping area outside the overlapping area with the pressure chamber 513. It is extended to. The vibrator-side end of the individual terminal 519 is connected to the drive electrode 524 in this non-overlapping region and is formed in a laminated state on the upper surface of the piezoelectric vibrator 518. A part of the individual terminal 519 formed on the piezoelectric vibrator 518 serves as a conductive portion with the wiring board 504 (contact terminal 520) (hereinafter also referred to as a conductive portion 519a). On the other hand, the end of the common upper electrode 533 is formed up to the front of the individual terminal 519, but is not electrically connected to each other because the separation region X is provided between the individual terminal 519.

  By adopting such a configuration, the actuator unit 503 can be downsized. That is, since the end of the individual terminal 519 is positively formed so as to overlap the surface of the piezoelectric vibrator 518, the individual terminal 519 can be formed as a whole close to the piezoelectric vibrator. Therefore, regarding the individual terminal 519, the width of the actuator unit 503, specifically, the longitudinal direction of the pressure chamber (vibrator) is ensured while ensuring the length necessary for conduction (that is, the length necessary for joining with the contact terminal 520). The width in the longitudinal direction can be shortened.

  Furthermore, since the individual terminals 519 extending in a comb shape from each of the two pressure chamber rows are formed so as to overlap in the nozzle row direction, the width in the pressure chamber longitudinal direction (vibrator longitudinal direction) is further shortened. can do.

  Due to this downsizing, more actuator units 503 can be laid out with respect to the ceramic sheet having the same area as the conventional one at the time of manufacture. Therefore, more actuator units 503 can be manufactured even in the same process as the conventional process, and the manufacturing efficiency can be improved. In addition, raw materials can be saved. As described above, since the manufacturing efficiency can be improved and the raw materials can be saved, the cost of the actuator unit 503 can be reduced.

  When connecting to the wiring board 504, as shown in FIG. 12, with the contact terminals 520 of the wiring board 504 superimposed on the individual terminals 519, a heating terminal (see FIG. By pressing (not shown), the individual terminal 519 and the contact terminal 520 can be melt-bonded (soldered). In this case, since the conducting portion 519a of the individual terminal 519 is located above the piezoelectric vibrator 518 and is at the highest position in the actuator unit 503, it is most strongly pressurized by the heating terminal. For this reason, soldering can be performed reliably.

  Furthermore, since the conducting portion 519a is formed on the piezoelectric vibrator 518, the rigidity of the member is increased, and the pressing force from the heating terminal can be reliably received.

  Next, the structure on the other side (nozzle opening 510 side) in the drive vibrator 518b will be described.

  As shown in FIGS. 11 and 13, on the other side of the drive vibrator 518b, the common upper electrode 533 and the common lower electrode 534 extend in the vibrator longitudinal direction. That is, the common lower electrode 534 is formed up to the lower surface of the common trunk electrode 521 through the diaphragm 515. The common upper electrode 533 is formed on the surface of the common lower electrode 534 through the end surface of the piezoelectric layer 522. Further, the common upper electrode 533 is also formed in series up to the lower surface of the common trunk electrode 521.

  Therefore, both the common upper electrode 533 and the common lower electrode 534 are electrically connected to the common trunk electrode 521.

  Next, the structure of the dummy vibrator 518a will be described. The basic structure of the dummy vibrator 518a is the same as that of the drive vibrator 518b described above. That is, as shown in FIGS. 14 and 15, this dummy vibrator 518a also includes an upper layer piezoelectric body 531 and a lower layer piezoelectric body 532, and also has a block-shaped piezoelectric body layer 522 elongated in the longitudinal direction of the pressure chamber. Electrode layers are provided between the plate 515 and the lower piezoelectric body 532, the boundary between the upper piezoelectric body 531 and the lower piezoelectric body 532, and the surface of the upper piezoelectric body 531 opposite to the lower piezoelectric body 532.

  In this embodiment, an electrode layer provided between the diaphragm 515 and the lower layer piezoelectric body 532 (hereinafter referred to as the first conduction electrode 535), and an electrode provided at the boundary between the upper layer piezoelectric body 531 and the lower layer piezoelectric body 532 A layer (hereinafter referred to as a second conductive electrode 536) extends to both sides in the longitudinal direction of the vibrator so that the common trunk electrode 521 and the individual terminal 519 are electrically connected. That is, the first conductive electrode 535 is formed in series from the common trunk electrode 521 through the lower piezoelectric body 532 to the individual terminals 519, and the second conductive electrode 536 passes from the common trunk electrode 521 under the upper piezoelectric body 531. Thus, the individual terminals 519 are formed in series. In the present embodiment, these conductive electrodes are made of the same electrode material as the common lower electrode 534 and the drive electrode 524.

  With this configuration, the individual terminal 519 provided on the dummy vibrator 518a and the common trunk electrode 521 are electrically connected via the conduction electrodes 535 and 536, and thus the individual terminal 519 is connected to the common potential (for example, the ground potential). ) Can be used as a supply terminal (common potential supply terminal). Since the individual terminals 519 are similarly formed in the same row as the individual terminals 519 for the drive vibrator 518b, the actuator unit 503 can be reduced in size. Further, when the wiring board 504 and the individual terminals 519 are brought into conduction, the individual terminals 519 for the dummy vibrator 518a and the individual terminals 519 for the driving vibrator 518b can be brought into conduction together, so that work efficiency can be improved.

  In addition, since these conductive electrodes are all provided below the piezoelectric layer 522, no burr-like portion is generated. For this reason, it is possible to reliably prevent a problem that the wiring is disconnected by the burr-like portion after the wiring board 504 is mounted or a short circuit is caused. Therefore, the recording head 501 can exhibit stable performance with few troubles.

  Furthermore, since these conducting electrodes 535 and 536 are divided into two layers, a sufficient thickness can be ensured. Thereby, the resistance value of an electrode can be restrained low. In addition, since each conductive electrode 535, 536 is made of the same electrode material as the common lower electrode 534 and the drive electrode 524, each conductive electrode 535, 536 is made simultaneously with the common lower electrode 534 and the drive electrode 524. Can do. That is, the first conduction electrode 535 can be produced at the same time as the common lower electrode 534, and the second conduction electrode 536 can be produced at the same time as the drive electrode 524. Thereby, it is not necessary to perform a forming process for forming the conductive electrode exclusively, and the manufacturing efficiency can be improved.

  9, the actuator unit 503 (and the flow path unit 502) have positioning reference holes 01 to 604 at positions outside the two rows of nozzle openings 510 and the two rows of pressure chambers 513. Preferably it is formed.

  In the example shown in FIG. 9, the vertical reference holes 601 and 603 and the horizontal reference holes 602 and 604 are outside the vicinity of the midpoint of each side of the rectangular shape formed by the two rows of pressure chambers 513. Is provided. One reference hole 601 is configured in a circular shape, and the other reference holes 602 to 604 are configured as long holes.

  Conventionally, the reference hole for positioning has been provided at the center of the unit member. However, the use efficiency of the space of the unit member can be improved by providing it at the periphery of the unit member.

FIG. 2 is an exploded perspective view of a recording head according to Embodiment 1 of the invention. 2A and 2B are a plan view and a cross-sectional view of the recording head according to Embodiment 1 of the invention. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the recording head according to the first embodiment of the invention. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the recording head according to the first embodiment of the invention. FIG. 6 is a cross-sectional view illustrating a manufacturing process of the recording head according to the first embodiment of the invention. 1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention. It is sectional drawing explaining the actuator unit and flow path unit in Embodiment 2 of this invention. It is the elements on larger scale explaining the nozzle plate which concerns on Embodiment 2 of this invention. It is the perspective view which looked at the actuator unit which concerns on Embodiment 2 of this invention from the piezoelectric vibrator side. It is sectional drawing explaining the structure of the piezoelectric vibrator which concerns on Embodiment 2 of this invention. It is a figure explaining the edge part structure of the drive vibrator concerning Embodiment 2 of the present invention. It is the A section enlarged view of FIG. It is the B section enlarged view of FIG. It is a figure explaining the structure of the one side edge part of the dummy vibrator | oscillator which concerns on Embodiment 2 of this invention. It is a figure explaining the structure of the other end part of the dummy vibrator | oscillator which concerns on Embodiment 2 of this invention. It is sectional drawing of the recording head which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate 11 Partition 12 Pressure generation chamber 13 Communication part 14 Ink supply path 20 Nozzle plate 21 Nozzle opening 30 Reservoir formation board 31 Reservoir part 32 Piezoelectric element holding part 33 Through hole 34 Ink introduction path 50 Elastic film (vibration plate)
60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode (part of upper electrode)
91 connection terminal portion 100 reservoir 110 drive circuit 120 connection wiring 300 piezoelectric element 501 recording head 502 flow path unit 503 actuator unit 504 wiring substrate 505 ink supply port 506 nozzle communication port 507 supply port formation substrate 508 common ink chamber 509 ink chamber formation substrate 510 Nozzle opening 511 Nozzle plate 512 Nozzle row 513 Pressure chamber 514 Pressure chamber forming substrate 515 Vibration plate 516 Supply side communication port 517 Lid member 518 Piezoelectric vibrator 519 Individual terminal 520 Contact terminal 521 of wiring board Common trunk electrode 522 Piezoelectric layer 523 Common branch electrode 524 Drive electrode (individual electrode)
531 Upper layer piezoelectric body 532 Lower layer piezoelectric body 533 Common upper electrode 534 Common lower electrode 535 First conduction electrode 536 Second conduction electrode 601 to 604 Reference hole

Claims (7)

A flow path forming substrate that communicates with each nozzle opening of the nozzle row and has a plurality of pressure generation chambers sealed by a diaphragm;
A plurality of pressure changing means provided on the diaphragm for changing the pressure of the liquid supplied into each of the plurality of pressure generating chambers and discharging the liquid from the corresponding nozzle openings;
A liquid jet head comprising:
The pressure generating chambers form two opposing pressure generating chamber rows parallel to the nozzle row direction,
Each pressure variation means is composed of a piezoelectric element having a common electrode, a piezoelectric layer and an individual electrode,
The individual electrodes of each piezoelectric element are extended toward the intermediate region sandwiched between the pressure generation chamber rows facing each other, and are formed to be narrower than the width of the individual electrode of the piezoelectric element only at a part of one side in the width direction. Connected to the connected terminal section,
Corresponding to each of the pressure generating chambers belonging to the other pressure generating chamber row and the connection terminal portion connected to the individual electrode of each piezoelectric element provided corresponding to each pressure generating chamber row belonging to one pressure generating chamber row A liquid ejecting head comprising: a connecting terminal portion connected to an individual electrode of each provided piezoelectric element; and a region that is parallel to each other and overlaps in a nozzle row direction. The liquid ejecting head according to claim 1, wherein a width of the connection terminal portion is ½ or less of a width of the individual electrode. 3. The liquid jet head according to claim 1, wherein the arrangement density of the connection terminal portions overlapping in the direction of the nozzle row is at least twice the arrangement density of the pressure generating chambers. 4. The liquid jet head according to claim 1, wherein the arrangement density of the connection terminal portions overlapping in the direction of the nozzle row is 240 dots / inch (dpi) or more. 5. The liquid jet head according to claim 1, wherein a length of a portion of the connection terminal portion that overlaps in a nozzle row direction is ½ or more of a total length of the connection terminal portion. . The positioning reference hole is formed in the flow path forming substrate at a position outside the two nozzle rows and the two pressure generation chamber rows. The liquid jet head described in 1. A liquid ejecting head according to any one of claims 1 to 6;
A liquid supply mechanism for supplying the liquid into each of the plurality of pressure generating chambers;
A liquid ejecting apparatus comprising:

Images