JP4905323B2 - Droplet discharge head - Google Patents

Description

  The present invention relates to a droplet discharge head that discharges droplets and the like.

  As an example of a liquid ejecting apparatus using an ink jet printer apparatus, a flow path unit having a liquid flow path to a nozzle hole for ejecting liquid droplets therein, and a nozzle hole by applying a discharge pressure to the liquid in the liquid flow path In some cases, there is provided a droplet discharge head configured by stacking a piezoelectric unit for discharging a liquid from a wiring unit and a wiring unit for outputting a signal to drive the piezoelectric unit (for example, see Patent Document 1).

  More specifically, as disclosed in Patent Document 1, in this type of droplet discharge head, on the upper surface of a flow path unit formed by laminating and bonding a plurality of plates having a rectangular shape in plan view, A piezoelectric unit formed by laminating and bonding a plurality of piezoelectric layers is laminated, and one end of a flexible belt-like wiring unit is laminated and bonded to the upper surface of the piezoelectric unit. In addition, a plurality of drive electrodes are disposed on the upper surface of the piezoelectric unit, and a plurality of power feeds disposed opposite to the drive electrodes are provided on the lower surface of the sheet-like base material of the wiring unit (the surface facing the upper surface of the piezoelectric unit). Terminals are provided. These drive electrodes and power supply terminals are electrically connected via solder. The flow path unit has an ink inlet for supplying ink into the flow path unit by being connected to an ink outlet of an ink tank which is an ink storage section.

On the other hand, when electrically connecting the electrode terminals via a conductive adhesive, in order to prevent the conductive adhesive from leaking and shorting with other electrode terminals, The invention which formed the flow prevention side groove of the adhesive has been proposed in the past (for example, see Patent Document 2). In this patent document 2, it is going to ensure the insulation state between the electrode terminals which should be electrically insulated by capturing the leaked conductive adhesive in a side groove.
JP 2006-44196 A (refer to FIG. 5 in particular) Japanese Patent Laid-Open No. 10-303517

  By the way, in the droplet discharge head as disclosed in Patent Document 1, ink leakage from the connection portion between the ink outlet and the ink inlet, or the user dropping the inkjet printer device, the nozzle hole causes There is a possibility that the ejected ink may enter a slight gap between the piezoelectric unit and the wiring unit. In this case, there is a possibility that an unexpected electrode terminal may be short-circuited by the liquid that has entered, which is not preferable. In addition, the invention disclosed in Patent Document 2 is for preventing a short-circuit between adjacent electrode terminals due to diffusion of the conductive adhesive, and is suitable for preventing liquid that has entered from the outside. The configuration is not disclosed.

  On the other hand, by applying a liquid sealant to the opening portion of the gap between the piezoelectric unit and the wiring unit, that is, the gap along the outer peripheral edge of the piezoelectric unit and the wiring unit. The gap is liquid-tightly sealed. However, due to warping of the wiring unit and unevenness of the surface of the piezoelectric unit, there are variations in the opening of the gap at the time of connection, and generally the liquid sealant has a variation in the amount applied, and the volume after drying after application Therefore, there are cases where all of the opening portions cannot be properly sealed.

  Accordingly, the present invention provides a liquid discharge head that can appropriately prevent short-circuits between individual drive electrodes of a piezoelectric unit and between individual power supply terminals of a wiring unit due to liquid that has entered from the outside. Objective.

  The present invention has been made in view of the above-described circumstances, and a droplet discharge head according to the present invention includes a piezoelectric unit having a drive electrode disposed on one surface thereof, and the one surface of the piezoelectric unit. A power supply terminal that is laminated on and electrically connected to the drive electrode includes a wiring unit having a sheet-like substrate provided on a surface facing the piezoelectric unit, and the power supply terminal to the drive electrode By driving the piezoelectric unit based on a driving signal, the liquid discharge head discharges the liquid in the liquid flow path included in the flow path unit stacked on the other surface of the piezoelectric unit to the outside. A plurality of drive units driven by the drive signal, wherein the drive electrodes are connected to the drive units individually and a plurality of the individual drives connected in common to the drive units; electrode And the power supply terminal of the wiring unit includes a plurality of individual power supply terminals provided at positions corresponding to the plurality of individual drive electrodes. A group and a common power supply terminal provided at a position corresponding to the common drive electrode, and the wiring unit is stacked on a surface of the base material facing the piezoelectric unit, and the individual power supply through an opening. An insulating coating layer that covers the other portion while exposing the terminal and the common power supply terminal to the piezoelectric unit side, and the coating layer has a peripheral portion corresponding to the outer peripheral edge of the piezoelectric unit. A trap groove is formed so as to be located inward so as to surround the individual power supply terminal group from the outside and to capture the liquid that opens to the piezoelectric unit side and enters from the outside.

  By adopting such a configuration, the trap groove is located at a position inward from the peripheral portion corresponding to the outer peripheral edge of the piezoelectric unit, so that the liquid that has entered from the outside can be captured by the trap groove. Furthermore, since the individual power supply terminal group individually connected to the drive unit driven by the drive signal is surrounded from the outside, a short circuit due to liquid intrusion between the individual power supply terminal and the individual drive electrode that affects driving is appropriately performed. Can be prevented, and the influence on the droplet discharge drive can be prevented.

  The trap groove may partition the individual power supply terminal group and the common power supply terminal. By adopting such a configuration, in addition to the effects described above, the trap groove is disposed inward from the common power supply terminal while surrounding the individual power supply terminal group, thereby extending the path from the outside to the trap groove. Therefore, the liquid itself entering the trap groove is reduced, so that the liquid can be more effectively prevented from entering the individual power supply terminals inside the trap groove.

  The base material has a configuration in which a first region on one end side is connected to the piezoelectric unit, and a second region on the other end side extends from the first region, and the individual power supply terminals and The common power supply terminal may be provided in the first region, and the wiring unit may further include an individual power supply wire connected to the individual power supply terminal and extending to the second region. By adopting such a configuration, a configuration suitable for driving as a droplet discharge head can be achieved, and ink that has entered from the gap between the opposing surfaces of the piezoelectric unit and the wiring unit can be reliably detected in the trap groove. And short circuiting between the individual drive electrodes and between the individual power supply terminals can be prevented.

  The trap groove may be formed in a region excluding a portion where the individual power supply terminal, the common power supply terminal, and the individual power supply wiring are located while surrounding the individual power supply terminal group from the outside. By adopting such a configuration, it is possible to prevent liquid from entering the individual power supply terminal, the common power supply terminal, and the individual power supply wiring from the outside. Can prevent short circuit.

  The covering layer is formed by laminating a first covering layer on the base material side and a second covering layer on the piezoelectric unit side, and the second covering layer entirely surrounds the individual feeding terminal group from the outside. The trap groove may be formed by notching the circumference. By adopting such a configuration, since the first coating layer of the two-layer coating layer covers the individual power supply wiring and the common power supply wiring, exposure of each wiring can be prevented. Further, since the trap groove can be formed in the second coating layer over the entire circumference surrounding the individual power supply terminal group, it is possible to prevent liquid from entering from all sides, thereby preventing liquid from entering more effectively. be able to.

  The first cover layer may have a notch that opens to the trap groove at a position excluding a portion corresponding to the individual power supply wiring. By adopting such a configuration, it is possible to increase the liquid volume that can be trapped by deepening the bottom of the trap groove, and to prevent the individual power supply wiring from being exposed to the outside.

  The trap groove may also extend between the plurality of openings exposing the individual power supply terminals. By adopting such a configuration, even if liquid enters inward from the trap grooves surrounding the individual power supply terminals, the trap grooves extending between the individual power supply terminals are separated. Since it can be captured, a short circuit between the individual power supply terminals partitioned by the trap groove is less likely to occur.

  According to the liquid discharge head according to the present invention, it is possible to appropriately prevent a short circuit between the individual drive electrodes included in the piezoelectric unit and between the individual power supply terminals included in the wiring unit due to the liquid that has entered from the outside.

  Hereinafter, a droplet discharge head according to an embodiment of the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a carriage on which a droplet discharge head according to this embodiment is mounted, and illustrates an inkjet printer head as the droplet discharge head. 1A shows a cross-sectional view of the ink jet head as viewed from one side, and FIG. 1B shows the ink jet head cut along line AA in FIG. 1A. FIG. As shown in FIG. 1, the carriage 1 includes, for example, an ink tank 3 that supplies inks (liquids) of each color such as cyan, magenta, yellow, and black independently to a flow path unit 10 described below, A holder case 4 that accommodates and holds the ink tank 3 and an inkjet head 6 that is attached to the lower portion of the holder case 4 via a support frame 5 are provided. In addition, the inkjet head 6 includes a flow path unit 10 having a plurality of plates laminated and bonded to each other and having a liquid flow path 10a (see FIG. 2) therein, and a piezoelectric unit that is stacked and bonded to the upper surface of the flow path unit 10. 11 and a wiring unit (chip-on-film) 12 connected to the upper surface of the piezoelectric unit 11.

  A driver IC 51 (see FIG. 3) as a drive circuit is connected to the wiring unit 12, and the driver IC 51 outputs a drive signal for selectively driving the piezoelectric unit based on print data from the main body side. The carriage 1 having such an ink jet head 6 is configured to be movable in parallel with the paper surface of the recording paper, similarly to a known ink jet printer device, and by ejecting ink droplets from the ink jet head 6 while moving. An image can be formed on the paper.

  2 is an enlarged cross-sectional view of the inkjet head 6 provided in the carriage 1 shown in FIG. 1. FIG. 3 is an exploded view of the inkjet head 6 into a flow path unit 10, a piezoelectric unit 11, a wiring unit 12, and a support frame 5. FIG.

  As shown in FIG. 2, the flow path unit 10 of the inkjet head 6 includes a pressure chamber plate 20, a first spacer plate 21, a throttle plate 22, a second spacer plate 23, a first common liquid chamber plate 24, and a second common. The liquid chamber plate 25, the damper plate 26, the cover plate 27, and the nozzle plate 28 are arranged from above in this order and are laminated and bonded to each other.

  Among these, the nozzle plate 28 is a resin sheet such as polyimide, and the other plates 21 to 27 are metal plates such as 42% nickel alloy steel plate (42 alloy), and each has a rectangular shape in plan view. , Each has a thickness of about 50 to 150 μm. Each of the plates 20 to 27 is formed with an opening or a recess constituting the liquid flow path (channel) 10a by electrolytic etching, laser processing, plasma jet processing, or the like.

  The nozzle plate 28 in the lowermost layer of the flow path unit 10 is provided with a large number of nozzle holes 28a for discharging ink droplets having a minute diameter at minute intervals, and the nozzle holes 28a are arranged in the long side direction of the nozzle plate 28 ( It is arranged in a row extending along the X direction in FIG. 3, and five rows are provided in the short side direction (the Y direction in FIG. 3). Further, the pressure chamber plate 20 located in the uppermost layer in the flow path unit 10 is formed with a plurality of pressure chamber holes 20a to be a plurality of pressure chambers 31 penetrating the pressure chamber plate 20 in the thickness direction, and the nozzle Five rows are provided in the Y direction in a row along the X direction corresponding to the holes 28a. The pressure chamber hole 20a has an elongated shape in plan view that is long in the Y direction, and is arranged such that its longitudinal direction (Y direction) is along the direction (X direction) orthogonal to the row of nozzle holes 28a. The plurality of pressure chamber holes 20a form a plurality of pressure chambers 31 having an internal space by laminating the piezoelectric actuator 11 from above and laminating the first spacer plate 21 from below.

  Each opening from the first spacer plate 21 to the cover plate 27 is formed to penetrate each opening serving as a nozzle communication channel 36 that communicates with one end portion of each pressure chamber 31 and communicates with each nozzle hole 28a. The first spacer plate 21, the diaphragm plate 22, and the second spacer plate 23 are formed with openings 21 a and 23 a and a groove 22 a serving as a connection flow path 33 that communicates the common ink chamber 35 and the other end of the pressure chamber 31. ing.

  The two manifold plates 24 and 25 are extended along the row direction (X direction) at a lower position corresponding to the position where the pressure chambers 31 are arranged in the row direction (X direction). Common ink chamber holes 24a and 25a serving as the common ink chamber 35 are formed through the manifold plates 24 and 25 in the thickness direction, and five rows are provided in the horizontal direction (Y direction). In addition, a damper wall 26 a having a concave surface opposite to the surface facing the common liquid chamber 35 in the damper plate 26 and having a thin wall thickness corresponds to the shape of the common liquid chamber 35. The second spacer plate 23, the two manifold plates 24 and 25, the damper plate 26, and the cover plate 27 are stacked in this order to form a common liquid chamber 35 and a damper space 26b. Is done. Further, a nozzle plate 28 having a plurality of nozzle holes 28a is laminated and bonded to the cover plate 27 from below.

  By laminating these plates 20 to 28, communicating openings and grooves are formed, and an ink flow path 10 a through which ink flows is formed. That is, the ink flow path 10a includes the common ink chamber 35, the connection flow path 33, the pressure chamber 31, the nozzle communication flow path 36, and the nozzle 28a. With the above configuration, the ink supplied from the ink tank 3 into the flow path unit 10 is guided to the nozzle 28a through the common ink chamber 35, the connection flow path 33, the pressure chamber 31, and the nozzle communication flow path 36 in order. .

  The plates 20 to 25 from the pressure chamber plate 20 to the manifold plates 24 and 25 correspond to four color inks by corresponding the upper and lower positions to one end in each longitudinal direction (X direction). Four ink supply ports 34 are formed (see FIG. 3). The four colors of ink from the ink tank 3 are independently supplied to the ink supply port 34. The ink supply port 34 into which frequently used black ink flows is formed larger than the other, and communicates with one end portion of the two common liquid chambers 35 in the X direction and is connected to the two ink flow paths 10a. Yes. The other ink supply ports 34 communicate with one end portion in the X direction of one common liquid chamber 35 independent of each other, and are connected with the remaining ink flow passage 10a. As described above, the flow path unit 10 has five ink flow paths, and the inkjet head 6 is configured to be able to eject four types of inks independently of each other.

As shown in FIG. 1, the ink supply port 34 has each ink for each ink color of the ink tank 3 mounted on the holder 4 when the inkjet head 6 is attached to the holder 4 via the support plate 5. The outlet 3 a and the ink connection ports 5 c of the support plate 5 are connected in communication. (See Figs. 1 and 3)
On the other hand, as shown in FIG. 2, the piezoelectric unit 11 has a rectangular shape that is long in the X direction in plan view, and a large number of rectangular piezoelectric sheets 40 to 45 that are long in the X direction and an insulating top sheet 46 are laminated. Has been configured. The piezoelectric sheets 40 to 45 are made of a lead zirconate titanate (PZT) ceramic material having a thickness of about 30 μm.

Among the piezoelectric sheets 40 to 45, a large number of piezoelectric sheets 41 and 43 that are counted upward from the lowermost piezoelectric sheet 40 are arranged on the upper surface so as to individually correspond to the positions of the pressure chambers 31. The individual electrodes 47 are printed and formed in five rows so as to correspond to the respective rows formed by the pressure chambers 31. Further, on the upper surface of the odd-numbered piezoelectric sheets 40, 42, 44 counted upward from the lowermost piezoelectric sheet 40, a common electrode is arranged so as to cover all the individual electrodes 47 for each row when viewed in plan. 48 is printed. The individual electrodes 47 and the common electrode 48 are drive electrodes provided on the upper surface of the top sheet 46 via relay wirings (not shown) provided on the side end surfaces of the piezoelectric sheets 40 to 45 and the top sheet 46 or through holes (not shown). 49 (see also FIG. 3). The common electrode 48 is grounded. The drive electrode 49 will be described in detail later. The electrodes 47 and 48 and the drive electrode 49 are screen-printed with an Ag—Pd-based conductive material.
The piezoelectric unit 11 has a smaller outer shape than the flow path unit 10 and is disposed so as to expose the ink supply port 34 at one end of the flow path unit 10 in the X direction. 47 and the pressure chamber 31 of the flow path unit 10 are laminated and joined so as to face each other in a plan view.

  One end of the wiring unit 12 is joined to the upper surface of the piezoelectric unit 11. The wiring unit 12 is a flexible strip-shaped wiring member, and has a plurality of power supply terminals 50 corresponding to the drive electrodes 49 on the upper surface of the piezoelectric unit 11, and the power supply terminals 50 are connected to the other end of the wiring unit 12. It is electrically connected to a provided IC chip 51 (see FIG. 3) by a lead wire (not shown). Further, as will be described later, solder bumps 52 are attached to the power supply terminal 50, and the piezoelectric unit 11 and the wiring unit 12 laminated on the upper surface of the piezoelectric unit 11 are heated and pressurized by a bar heater or the like through the melted solder bumps 52. Thus, the power supply terminal 50 and the drive electrode 49 are electrically connected.

  The inkjet head 6 having such a configuration operates as follows, and ejects ink droplets from the nozzle holes 28a. That is, ink is supplied from the ink outlet 3 a of the ink tank 3 to the ink connection hole 5 c and the ink supply port 34 of the support plate 5. A filter (not shown) is attached to the ink supply port 34. The ink supplied into the flow path unit 10 from the ink supply port 34 is filled in the liquid flow path 10 a including the common liquid chamber 35, the throttle path 33, the pressure chamber 31, and the nozzle communication path 36. In this state, when the driver IC 51 selectively applies a driving potential from the wiring unit 12 to the piezoelectric unit 11 according to the print data and selectively sets the plurality of individual electrodes 47 to a predetermined potential, the driver IC 51 is common to the individual electrodes 47 to which the potential is applied. A potential difference is generated between the electrode 48 and an electric field acts on the active portions of the piezoelectric sheets 41 to 44 to cause distortion in the stacking direction. Here, the active portion refers to a portion sandwiched between the individual electrode 47 and the common electrode 48 in each of the piezoelectric sheets 41 to 44, and substantially refers to a portion where distortion deformation in the stacking direction as described above occurs. When the active portion is deformed in this manner, the piezoelectric sheet protrudes into the corresponding pressure chamber 31, so that the internal pressure of the pressure chamber 31 rises and the internal liquid is discharged from the nozzle hole 28 a to the outside through the nozzle passage 36. The

  Such an inkjet head 6 is supported by the holder case 4 (see FIG. 1) by a support frame 5 having a rectangular frame shape as shown in FIG. More specifically, as shown in FIG. 3, the support frame 5 is a plate member having a rectangular shape in plan view, and its outer shape in plan view is larger than that of the flow path unit 10 and is rectangular in plan view in the central portion. It has a frame shape with an opening 5a formed therethrough. In addition, four ink connection holes 5c are formed through one end portion in the longitudinal direction (X direction) of the support frame 5 along the Y direction so that the ink outlet 3a and the ink supply port 34 communicate with each other. The opening 5a has an opening area that is slightly larger than the external dimensions of the piezoelectric unit 11 in plan view, and the support frame 5 has the piezoelectric unit 11 connected to one end of the wiring unit 12 in the opening 5a, and a wiring member. The other end portion of 12 is pulled out from the opening 5a and is fixed to the upper surface 10a of the flow path unit 10 by adhesion.

  At this time, a gap path 60 is formed between the inner peripheral part 5 b forming the opening 5 a in the support frame 5 and the outer peripheral part 11 a of the piezoelectric unit 11. The gap path 60 is filled with a liquid sealant 66 (see FIG. 2), and seals the joining boundary (gap) between the support frame 5, the flow path unit 10, and the piezoelectric unit 11.

  The support frame 5 is attached to the bottom of the holder case 4 with the adhesive 4a in a state where the support frame 5 is bonded and fixed to the flow path unit 10 in this way (see FIG. 1A). This adhesive 4a is applied over the entire circumference of the outer peripheral portion of the support frame 5, and the outside of the support frame 5 from the lower surface of the nozzle plate 28 of the flow path unit 10 (the surface on the side where the nozzle holes 28a open outward). A path that passes through the piezoelectric unit 11 through the adhesive 4a is closed by the adhesive 4a.

  However, the process of introducing the sealant into the gap path 60 is a handling operation, and the gap surrounding the outer peripheral portion 11a due to variations in the amount of sealant applied, fluidity variation, and the gap path 60 is narrow. In order to sufficiently introduce the sealant into the channel 60, it takes much time and effort. Further, the ink discharged from the nozzle hole 28 a or the way from the ink outlet 3 a of the ink tank 3 to the ink connection port 5 c and the ink supply port 34, and the connection between the flow path unit 10 and the piezoelectric unit 11 and the support frame 5. When ink leaked at any of the boundaries, etc., enters the gap unexpectedly because the gap between the small connecting surfaces of the piezoelectric unit 11 and the wiring unit 12 that are soldered is not sufficiently sealed. There is. If ink enters the slight gap, there is a possibility that the power supply terminals 50 or the drive electrodes 49 are short-circuited and the ink jet head 6 cannot exhibit desired liquid ejection characteristics. Therefore, in the inkjet head 6 according to the present embodiment, such a configuration as described below prevents such ink from entering a small connection space (gap) between the piezoelectric unit 11 and the wiring unit 12. Or, even if it penetrates, it is devised so as not to short-circuit between the power supply terminals 50 and between the drive electrodes 49. Hereinafter, such a configuration will be described.

Example 1
FIG. 4 is a plan view showing a configuration for preventing liquid intrusion into the gap between the connecting surfaces of the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (opposite to the piezoelectric unit 11). It is shown from the surface side. FIG. 5 shows a state where the wiring unit 12 shown in FIG. 4 is stacked on the piezoelectric unit 11 by a cross-sectional view taken along the line VV in FIG.

  As shown in FIG. 3, a plurality of drive electrodes 49 constituting a plurality of individual drive electrodes 49 a and a common drive electrode 49 b are arranged on the upper surface of the piezoelectric unit 11 (the upper surface of the top sheet 46 shown in FIG. 2). . The individual drive electrodes 49a are arranged in a row in the X direction and 5 rows in the Y direction so as to correspond to the pressure chamber rows, and the common drive electrodes 49b are arranged along the Y direction at both ends of the piezoelectric unit 1 in the X direction. It extends in a belt shape. The individual drive electrode 49a on the piezoelectric unit 11 side is electrically connected to the individual electrode 47 (see FIG. 2), and the common drive electrode 49b is electrically connected to the common electrode 48 (see FIG. 2) through a through hole. It is connected to the.

  Next, a more detailed configuration of the wiring unit 12 will be described. As shown in FIGS. 4 and 5, the wiring unit 12 has a flexible belt-like sheet-like base material 12a (thickness 38 μm), and a power supply terminal on the back surface side (the front side in FIG. 4) of the base material 12a. 50 and a conductive wire layer that forms a conductive wire 53, and a coating layer 70 such as polyimide or a photosensitive solder resist is laminated so as to cover the conductive wire layer and the base material 12a substantially over the wide surface. The sheet-like base material 12a is bonded to the piezoelectric unit 11 at one end side having the first region 121 and extends in the Y direction toward the other end side having the second region 122. The driver IC 51 (see FIG. 3 is also implemented.

  A plurality of power supply terminals 50 are disposed in the first region 121 of the conducting wire layer, and the power supply terminals 50 include a plurality of individual power supply terminals 50a and a plurality of common power supply terminals 50b. The individual power supply terminals 50a are provided at positions corresponding to the individual drive electrodes 49a, and form individual power supply terminal groups 50c arranged in rows in the X direction and in 10 rows in the Y direction. A plurality of common power supply terminals 50b are formed at appropriate distances along the Y direction at both ends in the width direction (X direction) so as to sandwich the individual power supply terminal group 50c from both sides. In addition, a plurality of output conductors 53 a connecting between the individual power supply terminals 50 a to the driver IC 51 in the second region 122 through the adjacent individual power supply terminals 50 a are drawn in the Y direction. An input lead wire 53b connected from the driver IC 51 to a terminal (not shown) provided on the other end side is patterned on the substrate 12a. In addition, at both ends in the width direction (X direction) of the wiring unit 12, a common electrode lead wire 53 c extending from the first region 121 to the second region 122 is formed in a strip shape extending to the other end along the Y direction. . These conducting wire layers are covered with an insulating covering layer 70, and the individual electrode terminals 50a are partially formed by openings 70a formed by partially removing the covering layer at positions corresponding to the individual electrode terminals 50a. Exposed to. Further, the common power supply terminal 50b is partially exposed to the piezoelectric unit 11 side by an opening 70b formed by removing a part of the coating layer 70 that covers the wired strip-shaped common electrode conducting wire 53c. A common electrode terminal 50b is formed. That is, the common power supply terminal 50b is the common electrode lead wire 53c itself.

  Solder bumps are formed on exposed portions of the individual electrode terminals 50a and the common electrode terminals 50b on the piezoelectric unit 11 side. Each electrode terminal 50 and each driving electrode 49 are aligned correspondingly, the wiring unit 12 and the piezoelectric unit 11 are laminated, and heated by pressing with a bar heater or the like from the upper surface of the wiring unit 12. And the electrode terminals 50 and the drive electrodes 49 are joined.

  In the case of the inkjet head 6 according to the present embodiment, a liquid sealant 71 is applied to the gap between the connection surfaces in the outermost peripheral portion of the piezoelectric unit 11 and the wiring unit 12 (the gap is opened outward). The gap is liquid-tightly sealed from the outside by entering the gap and curing. In the wiring unit 12 according to the present embodiment, the sealant 71 easily enters the gap in the outermost peripheral portion opened to the outside, so that the opening is reliably sealed.

  That is, as shown in FIG. 4, the covering layer 70 covering the lower surface of the sheet-like substrate 12 a is formed on the outermost peripheral portion 11 a of the rectangular piezoelectric unit when the wiring unit 12 is laminated and bonded to the piezoelectric unit 11. 5 except for the side on which the other end side of the wiring unit 12 is pulled out (left side in the Y direction in FIG. 4), the peripheral portion with respect to approximately three sides is removed (notch portion 73a), as shown in FIG. When viewed in cross section, the common electrode lead wire 53c or the base material 12a corresponding to the peripheral edge is exposed to the piezoelectric unit 11 side, and a gap (space) between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12 is present. ) Is expanded to form a sealant introduction groove 73 that opens outward.

  By forming such a sealant introduction groove 73, when the liquid sealant 71 is applied, the space into which the sealant 71 enters is widened in the notch 73a. The stopper 71 is more easily penetrated, and the operation of applying the liquid sealant 71 along the sealant introduction groove 73 is facilitated. That is, since the piezoelectric unit 11 and the wiring unit 12 are joined by being heated by a bar heater under pressure, generally the distance (gap) between the joining surfaces is extremely narrow. Although it is difficult to apply and seal, the entrance portion of the gap (that is, the sealing agent introduction groove 73) is slightly widened by the cutout portion 73a, so that the operation of applying the sealing agent 71 is facilitated. Further, since the applied sealant 71 is introduced along the sealant introduction groove 73 by capillary action, the application work is easy and the sealing effect is improved.

  As shown in FIG. 4, the notch 73 a is formed at the peripheral portion with respect to approximately three sides excluding the side where the other end side of the wiring unit 11 is drawn (left side in the Y direction in FIG. 4). The other end side is provided with a plurality of individual electrode lead wires 53a for outputting a signal for driving the piezoelectric unit 11, so that the lead wires 53a are prevented from being exposed and the individual power feeding is performed. The terminal 50a and the common power supply terminal 50b are not formed at positions where they are disposed. This is for preventing an electrical short circuit, a defect, and a mechanical connection defect by the sealant. In FIG. 5, the cut-out portion of a part of the common electrode lead wire 53c is exposed, but the common electrode lead wire 53c is grounded to the ground, so that it is not electrically affected. Therefore, as shown in FIG. 4, at the position where the common electrode conducting wire 53c is formed wide, the notch 73c can be provided, and the application area of the sealant is made wider.

A coating layer 70 is laminated on the lower surface of the sheet-like base material 12a so as to cover all of the individual power supply terminals 50a, the electrode plates 50d, and the conductive wires 53, and is shared with the individual power supply terminals 50a. When the openings 70a and 70b are formed by a known means such as photoresist, etching, or laser in a portion corresponding to the power supply terminal 50b, the outermost peripheral edge portion 70c (portion indicated by a broken line in FIG. 5) in the coating layer 70 The notch 73a is formed by removing the covering layer 70 and exposing the common electrode lead wire 53c and the base material 12a. If processing is possible, the notch 73a is formed on the piezoelectric actuator 11 side. You may form in the recessed part opened in. If it is a recess, the region from which the individual electrode conductor 53a is drawn is not exposed, so a notch can be formed in the entire peripheral edge facing the four outer sides of the piezoelectric unit 11, and the sealant It is possible to introduce the ink, and it is possible to prevent the ink from entering from four directions.

(Example 2)
FIG. 6 is a plan view showing another configuration for preventing liquid intrusion into the gap between the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (the side facing the piezoelectric unit 11). ). FIG. 7 is a partial cross-sectional view showing a state in which the wiring unit 12 shown in FIG. 6 is stacked on the piezoelectric unit 11.

  In the wiring unit 12 according to the present embodiment, the coating layer 70 that covers the lower surface of the sheet-like substrate 12a has a two-layer structure of a first coating layer 75 and a second coating material 76, and a sealing agent. The introduction groove 73 is different from the wiring unit 12 according to the first embodiment in that the introduction groove 73 extends over the entire circumference surrounding the individual power supply terminal 50a and the common power supply terminal 50b. Therefore, in the following, these points will be described in detail, and the other configurations are the same as those already described, and therefore the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 6 and 7, the covering layer 70 covers the conductive layer, the first covering layer 75 laminated and bonded so as to cover substantially the entire wide surface of the sheet-like substrate 12 a, and the piezoelectric unit 11. The second covering layer 76 has the same area as the outer shape and is laminated and bonded to the first covering layer 75. In each of the first covering layer 75 and the second covering layer 76, an opening 70a for exposing the individual power supply terminal 50a and an opening 70b for exposing the common power supply terminal 50b are formed in the respective layers. . The notch 77 forming the sealant introduction groove 73 is a surface on the piezoelectric unit 11 side of the second covering layer 76 so that the individual power supply terminal 50a and the common power supply terminal 50b are positioned inward. The unit 11 is formed in a rectangular shape corresponding to the entire outer periphery (four sides of the piezoelectric unit 11). As shown in FIG. 7, since the notch 77 is not formed in the first covering layer 75, the first covering layer 75 corresponding to the entire circumference along the outermost peripheral edge in the sectional view of FIG. 7 is exposed to the piezoelectric unit 11 side. It is in the state that was done. Since the first coating layer 75 covers the region where the conductive wire 53a is disposed in the portion of the wiring unit 11 on the drawn side, the cutout portion is formed in the second coating layer 75 corresponding to the four sides of the piezoelectric unit 11. 77 can be provided.

  According to the inkjet head 6 according to the present embodiment, since the sealant introduction groove 73 can be formed over the entire circumference surrounding the individual power supply terminal 50a and the common power supply terminal 50b, the terminals 50a and 50b can be formed from the entire periphery. It can be sealed with the sealant 71. Accordingly, it is possible to more effectively prevent liquid from entering. In addition, it cannot be overemphasized that the effect similar to what was demonstrated in Example 1 can be show | played also in the structure which concerns on a present Example. Further, the notch 77 may be a recess as in the first embodiment.

Example 3
FIG. 8 is a plan view showing another configuration for preventing liquid intrusion into the gap between the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (opposite side to the piezoelectric unit 11). ). FIG. 9 is a partial cross-sectional view showing a state in which the wiring unit 12 shown in FIG. 8 is stacked on the piezoelectric unit 11. The wiring unit 12 according to the present embodiment has a configuration in which the configuration according to the first embodiment and the configuration according to the second embodiment are combined.

  That is, as shown in FIGS. 8 and 9, the wiring unit 12 includes a coating layer 70 having a two-layer structure including a first coating layer 75 and a second coating layer 76. The second covering layer 76 is formed with a notch 77 extending over the entire circumference surrounding the individual power supply terminal 50a and the common power supply terminal 50b, as in the second embodiment. 75, as in the first embodiment, a cutout portion 73a is provided so as to surround the individual power supply terminal 50a and the common power supply terminal 50b from the outside except the portion corresponding to the position where the conducting wire 53a is disposed. Is formed. Further, when viewed in a plan view, the cutout portion 73a of the first coating layer 75 is formed so as to overlap with the cutout portion 77 of the second coating layer 76, and the sheet-like base material 12a is formed in the piezoelectric unit 11 at the overlapped portion. Exposed to the side.

  According to the ink jet head 6 according to the present embodiment, the same effects as those of the configurations according to the first and second embodiments can be obtained, and the individual power supply terminals 50a and the common power supply terminals 50b are liquid-tight over the entire periphery. In addition, the liquid can be effectively prevented from entering, and the cutout portions 73a and 77 are provided in both the first cover layer 75 and the second cover layer 76, so that the sealant is introduced. The opening area to the outside of the groove 73 is increased, and the application work of the sealant 71 becomes easier. In addition, the notch 73a may be formed in the recessed part similarly to having mentioned in Example 1. FIG.

  In Examples 1 to 3 described above, the example in which the sealant 70 is applied to the gap between the connection surfaces of the wiring unit 11 and the piezoelectric unit 12 is described. The liquid sealing agent 66 is filled into a substantially rectangular gap 60 formed between the inner peripheral portion 5b of the opening 5a and the outer peripheral portion 11a of the piezoelectric unit 11 attached to the support frame 5. (See FIG. 2). At this time, since the inkjet head 6 has the configuration as in the first to third embodiments, the liquid sealing agent 66 filled in the gap 60 is easily introduced into the sealing agent introduction groove 73. The gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12 can be easily sealed, and unexpected ink intrusion can be prevented.

Example 4
In the inkjet head 6 according to the present embodiment, unlike the first to third embodiments described above, the ink that has entered from the outside is to be captured before reaching the individual power supply terminal 50b, and a trap for that purpose. A groove 80 is provided. Such a configuration will be described with reference to FIGS.

  FIG. 10 is a plan view showing a configuration for capturing ink that has entered the gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (opposite to the piezoelectric unit 11). It is shown from the surface side. FIG. 11 is a partial cross-sectional view showing a state in which the wiring unit 12 shown in FIG. 10 is stacked on the piezoelectric unit 11.

  As shown in FIGS. 10 and 11, the wiring unit 12 is provided with a common power supply terminal 50b so as to sandwich the individual power supply terminal group 50c from both sides as in the first embodiment, and the sheet-like base material 12a. A coating layer 70 having a single layer structure is laminated on the lower surface of the substrate. The covering layer 70 has a substantially U-shaped trap surrounding the individual power supply terminal group 50 c at a position inside the outermost peripheral portion of the piezoelectric unit 11 (individual power supply electron group 50 c side). A groove 80 is formed to open downward (that is, toward the piezoelectric unit 11). Specifically, the wiring unit 12 extends linearly in the X direction from the side on one end side (the right side in FIG. 10), and both ends of the wiring unit 12 pass between the individual power supply terminal group 50c and the common electrode terminal 50b. It has a substantially U shape extending in the direction. The trap groove 80 is not formed in a portion of the coating layer 70 corresponding to the position where the individual electrode lead wire 53a is disposed, and prevents the lead wire 53a from being exposed to the outside.

  According to the ink jet head 6 according to this embodiment, even if ink enters the gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12 as shown in FIG. And can be blocked before reaching the individual power supply terminal 50a (and the individual drive electrode 49a).

  Note that the common drive electrode 49b and the common power supply terminal 49a do not cause a problem such as a short circuit even if they come into contact with ink because of their functions. In the configuration according to the present embodiment, the trap groove 80 is disposed inward of the common power supply terminal 49b (that is, a position close to the individual power supply terminal 49a). With such a configuration, it is possible to reduce the amount of liquid that reaches the trap groove 80 out of the liquid that enters inward from the gap between the piezoelectric unit 11 and the wiring unit 12. Therefore, the less liquid can be reliably captured by the trap groove 80.

  Further, even if a substantially U-shaped trap groove 80 along the outermost peripheral edge is formed at a position inside the outermost peripheral portion of the piezoelectric unit 11 (individual power supply terminal group 50c side), the trap Ink can be captured by the groove 80 to prevent ink from entering the individual power supply terminal group 50c. Further, the trap groove 80 may be formed in the concave portion in the same manner as described for the cutout portion 73c of the first embodiment.

(Example 5)
FIG. 12 is a plan view showing another configuration for capturing the liquid that has entered the gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the rear side (with the piezoelectric unit 11 and From the opposite surface side). FIG. 13 is a partial sectional view showing a state in which the wiring unit 12 shown in FIG. 12 is stacked on the piezoelectric unit 11.

  In the wiring unit 12 according to the present embodiment, the coating layer 70 that covers the lower surface of the sheet-like substrate 12a has a two-layer structure of a first coating layer 75 and a second coating material 76, and the trap groove 80. Is different from the wiring unit 12 according to the fourth embodiment in that it extends over the entire circumference surrounding the individual power supply terminal group 50c. Therefore, in the following, these points will be described in detail, and the other configurations are the same as those already described, and therefore the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 12 and 13, the covering layer 70 includes a first covering layer 75 similar to the structure according to the second embodiment and a second covering layer 76 laminated and adhered thereto. Each of the first covering layer 75 and the second covering layer 76 is formed with an opening 70a for exposing the individual power supply terminal 50a and an opening 70b for exposing the common power supply terminal 50b. On the other hand, the trap groove 80 cut out only about the second coating layer 76 is formed at a position surrounding the individual power supply terminal group 50 c, and the cutout is not formed in the first coating layer 75.

  The trap groove 80 formed in the second coating layer 76 is formed in a substantially rectangular shape that passes between the common power supply terminal 50b and the individual power supply terminal group 50c and surrounds the individual power supply terminal group 50c over the entire circumference. ing. Accordingly, the trap groove 80 is also formed in the portion of the second covering layer 76 corresponding to the portion where the conducting wire 53a is disposed. The first covering layer 75 is connected to the conducting wire 53a at the bottom of the trap groove 80. Since it is provided so as to cover, the conducting wire 53a is not exposed to the outside.

  According to the inkjet head 6 including such a wiring unit 12, the ink that has entered from the outside can be captured from four directions by the trap groove 80, as in the case of the configuration according to the fourth embodiment. Since the trap groove 80 is provided so as to surround the individual power supply terminal group 50c from the entire circumference, it is possible to prevent ink from entering from any direction. Further, the trap groove 80 may be formed in the concave portion as mentioned for the cutout portion 73a of the first embodiment. Further, the second coating layer 76 of the present embodiment and the coating layer 70 of the fourth embodiment may be combined and laminated so that the trap grooves 80 and 80 coincide (communicate). In this case, the positions of the trap grooves 80 and 80 overlap in the stacking direction, so that the ink capturing space of the trap grooves is widened, and the capturing effect is improved.

(Example 6)
FIG. 14 is a plan view showing another configuration for capturing the liquid that has entered the gap between the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (the side facing the piezoelectric unit 11). ). The wiring unit 12 according to the present embodiment has a configuration in which another trap groove 81 that passes through the individual power supply terminal group 50c is further provided to the wiring unit 12 according to the fifth embodiment. This is the same as that already described with reference to FIGS.

  The trap groove 81 extends linearly in the X direction by dividing the plurality of individual power supply terminals 50a constituting the individual power supply terminal group 50c for each ink channel (nozzle row) for each ink color. Further, both ends thereof are connected to a trap groove 80 surrounding the individual power supply terminal group 50c from the outside, and the trap grooves 80 and 81 communicate with each other.

  According to the liquid discharge head 6 including such a wiring unit 12, even if the liquid enters inward from the individual power supply terminal group 50 c, the ink can be captured by the trap groove 81 for each ink channel. Is possible. That is, since the trap groove 80 is partitioned for each ink channel (nozzle row) that discharges the same ink color, a short circuit may occur even when ink enters the area of the individual power supply terminal group 50c. It can be avoided that a certain terminal occurs only in an ink channel that discharges the same ink color, and influences an ink channel that discharges another ink color. For example, the individual power supply terminal group 501c and the individual power supply terminal group 502c correspond to ink channels having different ink colors to be ejected. If ink enters and the individual power supply terminals 501c and 502c cause a short circuit, two colors are generated. An ejection failure occurs in the ink channel that ejects the ink, but such a failure can be prevented. Preferably, the trap grooves 80 are formed in a lattice shape for partitioning each individual power supply terminal 50.

  Further, since the trap groove 81 communicates with the trap groove 80, the liquid captured in the trap groove 80 surrounding the individual power supply terminal group 50c can be diffused into the trap groove 81 by capillary action. For this reason, it is equivalent to the capacity of the trap groove 80 being substantially increased by the capacity of the trap groove 81, and more liquid entering from the outside can be captured.

  Note that the trap groove 80 and the trap groove 81 do not necessarily need to communicate with each other. 14 shows a configuration in which three trap grooves 81 are provided, but it is better to provide more trap grooves 81 in terms of a substantial increase in the capacity of the trap grooves 80.

  Further, even in the case of a one-layer coating layer structure as in the first embodiment, the same effect can be obtained by simply forming a trap groove for each ink channel if a depression can be formed in the coating layer.

  The ink jet head 6 having the configuration as in the above Examples 4 to 6 is attached to the support frame 5 and is formed in a substantially rectangular shape formed between the inner peripheral portion 5b of the opening 5a and the outer peripheral portion 11a of the piezoelectric unit 11. When the liquid sealant 66 (see FIG. 2) was filled in the gap path 60, the sealant was not sufficiently sealed in the gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12. Even in this case, unexpected ink intrusion can be prevented.

(Example 7)
FIG. 15 is a plan view showing another configuration for capturing the liquid that has entered the gap between the piezoelectric unit 11 and the wiring unit 12, and the configuration of the wiring unit 12 is the back side (the side facing the piezoelectric unit 11). ). The wiring unit 12 according to the present embodiment includes a configuration (see FIG. 4) including the notch 73a that forms the sealant introduction groove 73 described in the first embodiment, and the trap groove 80 described in the fourth embodiment. This is a combination of the configuration provided (see FIG. 10).

  That is, in the covering layer 70 of the wiring unit 12, a notch 73 a is formed in a portion corresponding to the outermost peripheral edge of the piezoelectric unit 11 so as to surround the individual power supply terminal 50 a and the common power supply terminal 50 b from the outside. When the wiring unit 12 and the piezoelectric unit 11 are laminated, the notch 73a forms a sealant introduction groove 73 that opens outward as in the case shown in FIG. A trap groove 80 is formed in the coating layer 70 so as to pass between the common power supply terminal 50b and the individual power supply terminal group 50c and to surround the individual power supply terminal group 50c from the outside. Since other configurations are the same as those already described, the detailed description is omitted by assigning the same reference numerals to the corresponding configurations.

  By setting it as such a structure, there can exist an effect similar to each structure of Example 1 and Example 4. FIG. That is, the sealant 71 can be easily applied to the sealant introduction groove 73 formed by the notch 73a, and liquid can be prevented from entering the gap between the piezoelectric unit 11 and the wiring unit 12. be able to. In addition to this, even if the liquid enters the gap, the liquid that has entered can be captured by the trap groove 80, so that it is possible to prevent the individual power supply terminal 50a from being short-circuited by the liquid. it can.

  In addition, although the present Example demonstrated the combination of Example 1 and Example 4 mentioned above, arbitrary one of Examples 1-3 and arbitrary one of Examples 4-6 were used. Combinations are also possible.

  Further, the inkjet head 6 having the configuration as in the seventh embodiment is attached to the support frame 5 and has a substantially rectangular shape formed between the inner peripheral portion 5b of the opening 5a and the outer peripheral portion 11a of the piezoelectric unit 11. When the liquid sealant 66 (see FIG. 2) is filled in the gap path 60, the liquid sealant 66 filled in the gap path 60 is easily introduced into the sealant introduction groove 73, and the piezoelectric unit. 11 can easily seal the gap between the connection surfaces of the wiring unit 12 and the ink can be prevented from entering unexpectedly. Furthermore, even if the sealing agent is not sufficiently sealed in the gap between the connection surfaces of the piezoelectric unit 11 and the wiring unit 12, unexpected ink intrusion can be prevented.

  The present invention can be applied to a droplet discharge head that can appropriately prevent a short circuit between individual drive electrodes of a piezoelectric unit and between individual power supply terminals of a wiring unit due to liquid that has entered from the outside. it can.

It is sectional drawing of a carriage provided with the droplet discharge head which concerns on this Embodiment which makes an inkjet printer head an example. It is an expanded sectional view of the inkjet head with which the carriage shown in FIG. 1 is provided. It is a perspective view when an inkjet head is disassembled into a flow path unit, a piezoelectric unit, a wiring unit, a heat conductive plate material, and a support frame. It is a top view which shows the structure for preventing the liquid penetration | invasion to the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back surface side (opposite surface side with a piezoelectric unit). FIG. 5 is a partial cross-sectional view showing a state in which the wiring unit shown in FIG. 4 is stacked on the piezoelectric unit. It is a top view which shows the other structure for preventing the liquid penetration | invasion to the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back surface side. FIG. 7 is a partial cross-sectional view showing a state in which the wiring unit shown in FIG. 6 is stacked on the piezoelectric unit. It is a top view which shows the other structure for preventing the liquid penetration | invasion to the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back surface side. FIG. 9 is a partial cross-sectional view illustrating a state in which the wiring unit illustrated in FIG. 8 is stacked on the piezoelectric unit. It is a top view which shows the structure for capturing the liquid which permeated into the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back side. The state where the wiring unit shown in FIG. 10 is laminated on the piezoelectric unit is shown by a partial cross-sectional view. It is a top view which shows the other structure for catching the liquid which permeated into the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back side. FIG. 13 is a partial cross-sectional view illustrating a state in which the wiring unit illustrated in FIG. 12 is stacked on the piezoelectric unit. It is a top view which shows the other structure for catching the liquid which permeated into the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back side. It is a top view which shows the other structure for catching the liquid which permeated into the clearance gap between a piezoelectric unit and a wiring unit, and has shown the structure of the wiring unit from the back side.

Explanation of symbols

6 Liquid droplet ejection head 11 Piezoelectric unit 12 Wiring unit 12a Base sheet 49 Drive electrode 49a Individual drive electrode 49b Common drive electrode 50 Power supply terminal (land)
50a Individual power supply terminal 50b Common power supply terminal 50c Individual power supply terminal group 53 Conductor (individual power supply wiring, common power supply wiring)
70 Cover Layer 71 Sealant 73 Sealant Introducing Groove 73a, 77 Notch 75 First Cover Layer 76 Second Cover Layer 80, 81 Trap Groove 121 First Area 122 Second Area

Claims (7)

A piezoelectric unit having a drive electrode disposed on one surface thereof, and a power feeding terminal laminated on the one surface of the piezoelectric unit and electrically connected to the drive electrode are disposed on a surface facing the piezoelectric unit. A flow path unit stacked on the other surface of the piezoelectric unit by driving the piezoelectric unit based on a drive signal from the power supply terminal to the drive electrode. A liquid droplet ejection head for ejecting liquid in a liquid flow path to the outside,
The piezoelectric unit includes a plurality of driving units that are driven by the driving signal, and the driving electrodes are connected in common to the driving units and a plurality of individual driving electrodes individually connected to the driving unit. A common drive electrode disposed outside the plurality of individual drive electrodes,
The power supply terminal of the wiring unit includes an individual power supply terminal group including a plurality of individual power supply terminals provided at positions corresponding to the plurality of individual drive electrodes, and a common power supply provided at a position corresponding to the common drive electrodes. And the wiring unit is laminated on the surface of the substrate facing the piezoelectric unit, and the individual power supply terminal and the common power supply terminal are exposed to the piezoelectric unit side through the opening. It has an insulating covering layer that covers the part,
The coating layer is located on the inner side of the peripheral portion corresponding to the outer peripheral edge of the piezoelectric unit so as to surround the individual power supply terminal group from the outer side, and opens to the piezoelectric unit side to enter from the outside. A droplet discharge head, wherein a trap groove for capturing a liquid is formed.   The liquid droplet ejection head according to claim 1, wherein the trap groove further partitions the individual power supply terminal group and the common power supply terminal. The base material has a configuration in which a first region on one end side is connected to the piezoelectric unit and a second region on the other end side extends from the first region, and the individual power supply terminal and the common The power supply terminal is provided in the first region,
3. The droplet discharge head according to claim 1, wherein the wiring unit further includes an individual power supply wiring that is connected to the individual power supply terminal and extends to the second region.   The trap groove is formed in a region excluding a portion where the individual power supply terminal, the common power supply terminal, and the individual power supply wiring are located while surrounding the individual power supply terminal group from the outside. Item 4. The droplet discharge head according to Item 3.   The coating layer is formed by laminating a first coating layer on the substrate side and a second coating layer on the piezoelectric unit side, and the entire circumference of the second coating layer surrounding the individual power supply terminal group from the outside is formed. 4. The droplet discharge head according to claim 1, wherein the trap groove is formed by being cut out.   6. The droplet discharge head according to claim 5, wherein the first covering layer is formed with a notch opening in the trap groove at a position excluding a portion corresponding to the individual power supply wiring.   7. The droplet discharge head according to claim 3, wherein the trap groove is also extended between the plurality of openings that expose the individual power supply terminals. 8.

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