Liquid ejection head, recording apparatus, and method for manufacturing liquid ejection head

Abstract

This liquid ejection head is provided with a plurality of pressure chambers, a pressure chamber girder, a vibration plate, a plurality of separate electrodes, a plurality of wiring lines, and an insulating film. The plurality of pressure chambers include a first pressure chamber and a second pressure chamber adjacent to each other in a first direction. The pressure chamber girder is positioned between the first pressure chamber and the second pressure chamber. The vibration plate is positioned so as to overlap the first pressure chamber and the second pressure chamber in a plan view. The plurality of separate electrodes are positioned so as to overlap the plurality of pressure chambers in plan view. The plurality of wiring lines are electrically connected to the plurality of separate electrodes, respectively. The insulating film is positioned between a girder wiring line positioned so as to overlap the pressure chamber girder in a plan view and the vibration plate. The insulating film has a first surface opposed to the vibration plate and a second surface opposed to the girder wiring line, and is positioned so as to overlap the pressure chamber girder in a plan view. The length of the first surface along the first direction is smaller than the length of the second surface along the first direction.

Description

Technical Field

[0001] The disclosed embodiments relate to a liquid ejection head, a recording apparatus, and a method for manufacturing a liquid ejection head.

Background Art

[0002] As printing apparatuses, inkjet printers and inkjet plotters using an inkjet recording method are known. Such inkjet printing apparatuses are equipped with a liquid ejection head for ejecting a liquid.

[0003] In such a liquid ejection head, for example, miniaturization is achieved by disposing wiring drawn from an individual electrode provided on a piezoelectric element for ejecting a liquid on a pressure chamber row located between adjacent pressure chambers.

Prior Art Document

Patent Document

[0004]

Patent Document 1

Summary of the Invention

[0005] A liquid ejection head according to one aspect of the embodiment includes a plurality of pressure chambers, a pressure chamber row, a diaphragm, a plurality of individual electrodes, a plurality of wirings, and an insulating film. The plurality of pressure chambers include a first pressure chamber and a second pressure chamber adjacent to each other in a first direction. The pressure chamber row is located between the first pressure chamber and the second pressure chamber. The diaphragm is positioned so as to overlap from the first pressure chamber to the second pressure chamber in a plan view. The plurality of individual electrodes are respectively positioned so as to overlap the plurality of pressure chambers in a plan view. The plurality of wirings are electrically connected to each of the plurality of individual electrodes. The insulating film is located between the diaphragm and an on-beam wiring positioned so as to overlap the pressure chamber row in a plan view among the plurality of wirings. The insulating film has a first surface facing the diaphragm and a second surface facing the on-beam wiring, and is positioned so as to overlap the pressure chamber row in a plan view. The length of the first surface along the first direction is smaller than the length of the second surface along the first direction.

Brief Description of the Drawings

[0006]

Figure 1

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Figure 11A

Figure 11B

Figure 11C

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DETAILED DESCRIPTION OF THE INVENTION

[0007] In the above-described liquid ejection head, since the allowable amount with respect to misalignment in the manufacturing process is small, there is room for further improvement in terms of achieving miniaturization.

[0008] Therefore, there is an expectation for providing a liquid ejection head, a recording apparatus, and a method for manufacturing a liquid ejection head that can reduce problems associated with misalignment.

[0009] Hereinafter, embodiments of the liquid ejection head, recording apparatus, and method for manufacturing a liquid ejection head disclosed in the present application will be described with reference to the accompanying drawings. Note that the present disclosure is not limited by the embodiments described below. Also, the drawings are schematic, and it should be noted that the dimensional relationships between elements, the ratios of the elements, etc. may differ from reality. Furthermore, there may be portions where the dimensional relationships and ratios between the drawings are different from each other.

[0010] In addition, in the embodiments described below, expressions such as "constant", "orthogonal", "perpendicular", or "parallel" may be used, but these expressions do not necessarily require strict "constant", "orthogonal", "perpendicular", or "parallel". That is, each of the above expressions is assumed to allow for deviations such as manufacturing accuracy and installation accuracy.

[0011] Also, the respective embodiments can be appropriately combined within a range that does not conflict with the processing content. In addition, the same reference numerals are given to the same parts in the following embodiments, and duplicate explanations are omitted.

[0012] [Embodiment] <Configuration of Printer> First, an overview of a printer, which is an example of a recording apparatus according to an embodiment, will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view schematically showing a schematic front of the printer according to the embodiment. FIG. 2 is a plan view schematically showing a schematic plan of the printer according to the embodiment. The printer according to the embodiment is, for example, a color inkjet printer.

[0013] As shown in FIG. 1, the printer 1 includes a paper feed roller 2, a guide roller 3, an applicator 4, a head case 5, a plurality of conveyance rollers 6, a plurality of frames 7, a plurality of liquid ejection heads 8, a conveyance roller 9, a dryer 10, a conveyance roller 11, a sensor unit 12, and a recovery roller 13. The conveyance roller 6 is an example of a conveyance unit.

[0014] Furthermore, the printer 1 has a control unit 14 that controls each part of the printer 1. The control unit 14 controls the operations of the paper feed roller 2, the guide roller 3, the coater 4, the head case 5, the plurality of conveyance rollers 6, the plurality of frames 7, the plurality of liquid ejection heads 8, the conveyance roller 9, the dryer 10, the conveyance roller 11, the sensor unit 12, and the recovery roller 13.

[0015] The printer 1 records images and characters on the printing paper P by landing droplets on the printing paper P. The printing paper P is an example of a recording medium. The printing paper P is in a state of being wound around the paper feed roller 2 before use. The printer 1 conveys the printing paper P from the paper feed roller 2 through the guide roller 3 and the coater 4 into the inside of the head case 5.

[0016] The coater 4 uniformly applies a coating agent to the printing paper P. As a result, since the surface treatment can be performed on the printing paper P, the printing quality of the printer 1 can be improved.

[0017] The head case 5 houses a plurality of conveyance rollers 6, a plurality of frames 7, and a plurality of liquid ejection heads 8. Inside the head case 5, a space that is isolated from the outside is formed, except for a part such as a portion where the printing paper P enters and exits that is connected to the outside.

[0018] The internal space of the head case 5 has at least one of control factors such as temperature, humidity, and air pressure controlled by the control unit 14 as necessary. The conveyance roller 6 conveys the printing paper P inside the head case 5 near the liquid ejection head 8.

[0019] The frame 7 is a rectangular flat plate and is positioned close above the printing paper P conveyed by the conveyance roller 6. Also, as shown in FIG. 2, the frame 7 is positioned such that its longitudinal direction is orthogonal to the conveyance direction of the printing paper P. And inside the head case 5, a plurality (for example, four) of frames 7 are positioned at predetermined intervals along the conveyance direction of the printing paper P.

[0020] Liquid is supplied from a liquid tank (not shown) to the liquid ejection head 8, for example, ink. The liquid ejection head 8 ejects the liquid supplied from the liquid tank.

[0021] The control unit 14 controls the liquid ejection head 8 based on data such as images and characters, and causes the liquid to be ejected toward the printing paper P. The distance between the liquid ejection head 8 and the printing paper P is, for example, about 0.5 to 20 mm.

[0022] The liquid ejection head 8 is fixed to the frame 7. The liquid ejection head 8 is positioned such that its longitudinal direction is orthogonal to the conveyance direction of the printing paper P.

[0023] That is, the printer 1 according to the present embodiment is a so-called line printer in which the liquid ejection head 8 is fixed inside the printer 1. Note that the printer 1 according to the present embodiment is not limited to a line printer, and may be a so-called serial printer.

[0024] A serial printer is a printer that alternately performs an operation of recording while moving the liquid ejection head 8, for example, reciprocating it in a direction intersecting the conveyance direction of the printing paper P, such as a substantially orthogonal direction, and the conveyance of the printing paper P.

[0025] As shown in FIG. 2, a plurality (for example, five) of liquid ejection heads 8 are fixed to one frame 7. FIG. 2 shows an example in which three liquid ejection heads 8 are located in front of the conveyance direction of the printing paper P and two liquid ejection heads 8 are located behind, and the liquid ejection heads 8 are positioned so that the centers of the respective liquid ejection heads 8 do not overlap in the conveyance direction of the printing paper P.

[0026] And, a head group 8A is constituted by a plurality of liquid ejection heads 8 located on one frame 7. The four head groups 8A are located along the conveyance direction of the printing paper P. The liquid ejection heads 8 belonging to the same head group 8A are supplied with four colors of ink. Thereby, the printer 1 can perform printing with four colors of ink using the four head groups 8A.

[0027] The colors of the ink ejected from each liquid ejection head 8 are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 can print a color image on the printing paper P by controlling each liquid ejection head 8 to eject inks of a plurality of colors onto the printing paper P.

[0028] Note that, in order to perform surface treatment on the printing paper P, a coating agent may be ejected from the liquid ejection head 8 onto the printing paper P.

[0029] Also, the number of liquid ejection heads 8 included in one head group 8A and the number of head groups 8A mounted on the printer 1 can be appropriately changed according to the object to be printed and the printing conditions. For example, if printing within the range printable by one liquid ejection head 8, the number of liquid ejection heads 8 mounted on the printer 1 may be one.

[0030] The printing paper P that has undergone printing processing inside the head case 5 is conveyed outside the head case 5 by the conveying roller 9 and passes through the inside of the dryer 10. The dryer 10 dries the printed printing paper P. The printing paper P dried by the dryer 10 is conveyed by the conveying roller 11 and collected by the collecting roller 13.

[0031] In the printer 1, by drying the printing paper P with the dryer 10, it is possible to suppress the printed printing papers P from adhering to each other when being wound up overlappingly and the un-dried liquid from being rubbed at the collecting roller 13.

[0032] The sensor unit 12 is composed of a position sensor, a speed sensor, a temperature sensor, etc. The control unit 14 can judge the states of the respective parts of the printer 1 based on the information from the sensor unit 12 and control the respective parts of the printer 1.

[0033] In the printer 1 described so far, the case where printing paper P is used as the printing target (i.e., the recording medium) has been shown. However, the printing target in the printer 1 is not limited to the printing paper P, and a roll-shaped cloth or the like may be used as the printing target.

[0034] Further, instead of directly transporting the printing paper P, the printer 1 may be configured to place it on a transport belt and transport it. By using the transport belt, the printer 1 can use single-sheet paper, cut cloth, wood, tiles, etc. as the printing target.

[0035] Further, the printer 1 may print wiring patterns of electronic devices or the like by discharging a liquid containing conductive particles from the liquid discharge head 8. Further, the printer 1 may produce chemicals by discharging a predetermined amount of a chemical agent or a liquid containing a chemical agent from the liquid discharge head 8 toward a reaction vessel or the like.

[0036] Further, the printer 1 may be provided with a cleaning unit for cleaning the liquid discharge head 8. The cleaning unit cleans the liquid discharge head 8 by, for example, wiping treatment or capping treatment.

[0037] The wiping treatment is, for example, a treatment for removing the liquid adhering to the liquid discharge head 8 by wiping the surface of the portion where the liquid is discharged with a flexible wiper.

[0038] Further, the capping treatment is carried out, for example, as follows. First, a cap is put on so as to cover the portion where the liquid is discharged, for example, the bottom surface 8e (see FIG. 4) of the liquid discharge head 8 (this is called capping). Thereby, a substantially sealed space is formed between the bottom surface 8e and the cap.

[0039] Next, the discharge of the liquid is repeated in such a sealed space. Thereby, it is possible to remove a liquid having a higher viscosity than the standard state or foreign matters that have clogged the nozzles 23 (see FIG. 4).

[0040] <Configuration of Liquid Discharge Head> [First Embodiment] Next, with reference to FIGS. 3 to 5, the configuration of the liquid discharge head 8 according to the first embodiment will be described. FIG. 3 is a plan view showing an example of a schematic configuration of the liquid discharge head according to the first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. 3.

[0041] For ease of explanation, FIG. 3 shows a three-dimensional orthogonal coordinate system including a Z-axis with the vertically upward direction as the positive direction. Such an orthogonal coordinate system may also be shown in other drawings used in the following description. In the following description, for convenience, the direction in which the bottom surface 8e (see FIG. 4) of the liquid discharge head 8 is located in the liquid discharge head 8, that is, the negative Z-axis side, may be referred to as "down" or "downward", and the positive Z-axis side may be referred to as "up" or "upward".

[0042] As shown in FIG. 3, the liquid discharge head 8 includes a pressure chamber 20, a pressure chamber beam 21, and a piezoelectric element 30. The pressure chamber 20 is a hollow region having a substantially rectangular planar shape with rounded corners. As shown in FIG. 3, the liquid discharge head 8 has a plurality of pressure chambers 20 positioned such that the longitudinal direction is along the Y-axis direction. Liquid is supplied into the pressure chamber 20 from a supply flow path (not shown).

[0043] The pressure chamber beam 21 is located between adjacent pressure chambers 20 in the X-axis direction. The plurality of pressure chambers 20 and pressure chamber beams 21 are alternately arranged in the X-axis direction to form a pressure chamber group. Such pressure chamber groups are arranged in a plurality in the Y-axis direction. Note that the pressure chamber groups may be arranged in a plurality in both the Y-axis direction and the X-axis direction.

[0044] The piezoelectric element 30 is respectively positioned so as to overlap each pressure chamber 20 in a plan view. The piezoelectric element 30 is displaced by energization to change the internal pressure of the pressure chamber 20.

[0045] Also, as shown in FIG. 4, the liquid discharge head 8 further includes a nozzle layer 22, a diaphragm 24, an individual electrode 35, and a wiring 25.

[0046] The nozzle layer 22 is located on the bottom surface 8e side of the liquid ejection head 8 and closes the lower end side of the pressure chamber 20. The nozzle layer 22 has nozzles 23. The nozzles 23 are through holes that penetrate the nozzle layer 22 in the thickness direction (Z-axis direction), and the liquid supplied into the pressure chamber 20 is ejected to the outside from the nozzles 23.

[0047] The plurality of pressure chambers 20 include a first pressure chamber 20a and a second pressure chamber 20b that are adjacent to each other in the X-axis direction with the pressure chamber row 21 interposed therebetween. The X-axis direction is an example of the first direction.

[0048] The diaphragm 24 is located above the pressure chamber 20 and the pressure chamber row 21. As shown in FIG. 4, the diaphragm 24 is positioned so as to overlap from the first pressure chamber 20a to the second pressure chamber 20b in plan view.

[0049] The individual electrodes 35 are respectively positioned so as to overlap each pressure chamber 20 in plan view. Each individual electrode 35 is electrically connected to the corresponding piezoelectric element 30. The individual electrodes 35 according to the embodiment are located on the diaphragm 24. The individual electrodes 35 may be located side by side with the piezoelectric elements 30, or may be located above or below the piezoelectric elements 30.

[0050] The wiring 25 is positioned so as to overlap the pressure chamber row 21 in plan view. The wiring 25 is an example of a wiring on a row. The wiring 25 according to the embodiment is located on the diaphragm 24. The wiring 25 is electrically connected to, for example, any one of the plurality of individual electrodes 35. The wiring 25 extends in the Y-axis direction intersecting the X-axis direction.

[0051] Next, with reference to FIG. 5, the wiring 25 according to the present embodiment and the configuration in the vicinity thereof will be further described. FIG. 5 is an enlarged cross-sectional view of the region V shown in FIG. 4.

[0052] As shown in FIG. 5, the liquid ejection head 8 further includes an insulating film 26. The insulating film 26 is positioned so as to overlap the pressure chamber row 21 in plan view. The insulating film 26 is located between the diaphragm 24 and the wiring 25.

[0053] Here, the details of the insulating film 26 will be further described with reference to FIGS. 5 and 6. FIG. 6 is a cross-sectional view showing an example of the configuration of the insulating film included in the liquid ejection head according to the first embodiment.

[0054] The insulating film 26 has a first surface 26a facing the diaphragm 24, a second surface 26b facing the wiring 25, and a third surface 26c connecting the first surface 26a and the second surface 26b. Also, the length L1 of the first surface 26a along the X-axis direction is smaller than the length L2 of the second surface 26b along the X-axis direction. As a result, it becomes difficult for the insulating film 26 to be positioned above the pressure chamber 20, so that the problem of inhibiting the displacement of the pressure chamber 20 can be reduced. Further, an increase in the size of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the insulating film 26 is displaced in the X-axis direction from a predetermined position can be reduced.

[0055] Also, since the length L2 of the second surface 26b of the insulating film 26 is larger than the length L1 of the first surface 26a, it becomes easier to ensure the insulation of the wiring 25 even when the wiring 25 is displaced in the X-axis direction from a predetermined position.

[0056] Also, as shown in FIG. 6, the angle θ formed by the first surface 26a and the third surface 26c can be, for example, about 5° to 20°. Also, the ratio L1 / L2×100 of the length L1 of the first surface 26a to the length L2 of the second surface 26b can be 75 (%) to 99 (%), particularly 75 (%) to 97 (%).

[0057] Returning to FIG. 5, the wiring 25 has a first end face 25a facing the insulating film 26 and a second end face 25b located on the opposite side of the first end face 25a. Also, the length L11 of the first end face 25a along the X-axis direction may be smaller than the length L12 of the second end face 25b along the X-axis direction. As a result, it becomes difficult for the wiring 25 to be positioned above the pressure chamber 20, so that the problem of inhibiting the displacement of the pressure chamber 20 can be reduced. Further, an increase in the size of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position can be reduced.

[0058] Further, since the length L12 of the second end face 25b of the wiring 25 is greater than the length L11 of the first end face 25a, the cross-sectional area of the wiring 25 can be increased as compared with the case where the length L12 is less than or equal to the length L11, and the electrical resistance of the wiring 25 can be reduced.

[0059] Further, the liquid ejection head 8 may further include a protective film 27 that covers the wiring 25. Thereby, the durability of the wiring 25 can be enhanced. The protective film 27 may have, for example, insulating properties. Also, the material of the protective film 27 may be the same as or different from, for example, the material of the insulating film 26.

[0060] Note that FIG. 6 shows an example of the configuration of the liquid ejection head 8, and may further include members other than the members shown in FIG. 6.

[0061] [Second Embodiment] FIG. 7 is a cross-sectional view showing an example of a schematic configuration of a liquid ejection head according to the second embodiment. As shown in FIG. 7, for the wiring 25, the length L21 of the first end face 25a along the X-axis direction may be greater than the length L22 of the second end face 25b along the X-axis direction. Thereby, since the contact area between the wiring 25 and the insulating film 26 can be increased, for example, the adhesion of the wiring 25 is improved.

[0062] [Third Embodiment] FIG. 8 is a cross-sectional view showing an example of a schematic configuration of a liquid ejection head according to a third embodiment. The liquid ejection head 8 shown in FIG. 8 has a plurality of wirings 25 arranged in the X-axis direction. The wiring 25 has three wirings 25-1 to 25-3. The total length L31 of the lengths L31-1 to L31-3 of the first end faces 25a of the wiring 25 along the X-axis direction may be smaller than the total length L32 of the lengths L32-1 to L32-3 of the second end faces 25b of the wiring 25 along the X-axis direction. Thereby, since it becomes difficult for one or a plurality of wirings 25 to be located above the pressure chamber 20, the problem of inhibiting the displacement of the pressure chamber 20 can be reduced. In addition, an increase in the size of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position can be reduced.

[0063] Further, since the total length L32 of the second end faces 25b of the wiring 25 is larger than the total length L31 of the first end faces 25a, the cross-sectional area of the wiring 25 can be increased as compared with the case where the total length L32 is equal to or less than the total length L31, and the electrical resistance of the wiring 25 can be reduced.

[0064] In FIG. 8, the liquid ejection head 8 in which three wirings 25 are arranged in the X-axis direction is illustrated, but the number of wirings 25 arranged in the X-axis direction may be two or four or more.

[0065] [Fourth Embodiment] FIG. 9 is a cross-sectional view showing an example of a schematic configuration of a liquid ejection head according to a fourth embodiment. The liquid ejection head 8 shown in FIG. 9 has three or more wirings 25 arranged in the X-axis direction. Among the three or more wirings 25 arranged in the X-axis direction, the total length of the first end faces 25a along the X-axis direction of the wirings 25 located at both ends in the X-axis direction, that is, the wirings 25-1 and 25-2 (= length (L41-1) + length (41-2)) may be smaller than the total length of the second end faces 25b along the X-axis direction (= length (L42-1) + length (42-2)). Thereby, since it becomes difficult for one or a plurality of wirings 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. In addition, it is possible to reduce the enlargement of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position.

[0066] Further, among the three or more wirings 25 arranged in the X-axis direction, the difference between the length L42-3 of the second end face 25b along the X-axis direction and the length 41-3 of the first end face 25a in the wiring 25-3 which is the wiring 25 located in the central portion in the X-axis direction may be smaller than the difference between the total length of the second end faces 25b along the X-axis direction and the total length of the first end faces 25a in the wirings 25-1 and 25-2 located at both ends in the X-axis direction. Thereby, while securing a wiring pitch within a predetermined region above the insulating film 26, it is possible to secure the cross-sectional area of the wiring 25 and reduce the electrical resistance of the wiring 25. In such a case, the length L41-3 may be the same as or different from the length 42-3.

[0067] In FIG. 9, the liquid ejection head 8 in which three wirings 25 are arranged in the X-axis direction and one wiring 25 is located in the central portion in the X-axis direction is illustrated, but the number of wirings 25 arranged in the X-axis direction may be four or more. In such a case, in the central portion in the X-axis direction, two or more wirings 25 excluding the wirings 25-1 and 25-2 located at both ends in the X-axis direction will be located. At this time, the difference between the total length of the second end face 25b along the X-axis direction in two or more upper wirings located in the central portion in the X-axis direction and the total length of the first end face 25a along the X-axis direction may be smaller than the difference between the total length of the second end face 25b along the X-axis direction and the total length of the first end face 25a in the wirings 25-1 and 25-2 located at both ends in the X-axis direction. Thereby, while securing a wiring pitch within a predetermined region above the insulating film 26, the cross-sectional area of the wiring 25 can be secured, and the electrical resistance of the wiring 25 can be reduced.

[0068] [Fifth Embodiment] FIG. 10 is a cross-sectional view showing a schematic configuration of a liquid ejection head according to the fifth embodiment. As shown in FIG. 10, in the liquid ejection head 8 according to the present embodiment, the cross-sectional shape of the wiring 25-3 located in the central portion in the X-axis direction is different from that of the liquid ejection head 8 shown in FIG. 8. Specifically, in the wirings 25-1 and 25-2, the length of the first end face 25a along the X-axis direction is smaller than the length of the second end face 25b, whereas in the wiring 25-3, the length of the first end face 25a along the X-axis direction is larger than the length of the second end face 25b. Thereby, since it becomes difficult for one or a plurality of wirings 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. In addition, it is possible to reduce the enlargement of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position. Also, a plurality of wirings 25 can be efficiently arranged within a predetermined region above the insulating film 26. At this time, the cross-sectional areas of the plurality of wirings 25 may be the same. Thereby, since the electrical resistances of the plurality of wirings 25 can be made uniform, the performance of the liquid ejection head 8 is improved.

[0069] In FIG. 10, a liquid ejection head 8 in which three wirings 25 are arranged in the X-axis direction and one wiring 25 is located in the central portion in the X-axis direction is illustrated. However, the number of wirings 25 arranged in the X-axis direction may be four or more. In such a case, for one or more wirings 25 located in the central portion in the X-axis direction, the length of the first end face 25a along the X-axis direction may be larger than the length of the second end face 25b. As a result, since it becomes difficult for one or a plurality of wirings 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. Further, it is possible to reduce the increase in size of the liquid ejection head 8 due to manufacturing convenience in consideration of the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position. Further, a plurality of wirings 25 can be efficiently arranged within a predetermined region above the insulating film 26. At this time, the cross-sectional areas of two or more wirings 25 located in the central portion in the X-axis direction may be the same, and further, may be the same as the cross-sectional areas of the wirings 25 located at both ends in the X-axis direction. As a result, since the electrical resistances of the plurality of wirings 25 can be made uniform, the performance of the liquid ejection head 8 is improved.

[0070] [Sixth Embodiment] FIG. 11A is a cross-sectional view showing an example of the configuration of an insulating film included in a liquid ejection head according to the sixth embodiment. FIGS. 11B and 11C are cross-sectional views showing other examples of the configuration of the insulating film included in the liquid ejection head according to the sixth embodiment.

[0071] As shown in FIG. 11A, the insulating film 26 may have a first portion 261 having the same width in the X-axis direction as the first surface 26a and a second portion 262 having the same width as the second surface 26b.

[0072] Further, as shown in FIG. 11B, the insulating film 26 may have a fourth surface 26d extending along the YZ plane from both ends of the second surface 26b along the X-axis direction and a fifth surface 26e connecting the fourth surface 26d and the first surface 26a. Such an insulating film 26 is relatively easy to manufacture, for example.

[0073] Further, as shown in FIG. 11C, the insulating film 26 may have a first inclined surface 26f whose width in the X-axis direction gradually decreases from the first surface 26a toward the constricted portion 26g, and a second inclined surface 26h whose width in the X-axis direction gradually increases from the constricted portion 26g toward the second surface 26b. According to such an insulating film 26, for example, even when dew condensation occurs on the surface of the insulating film 26, it becomes easier to dry and the durability is improved.

[0074] Note that the insulating film 26 according to the present embodiment can be manufactured by appropriately combining known methods such as dry etching and lift-off method. Further, for example, the shape of the insulating film 26 shown in FIGS. 11A to 11C may be applied to the shape of the wiring 25.

[0075] [Seventh Embodiment] FIG. 12 is a cross-sectional view showing an example of a schematic configuration of a liquid ejection head according to the seventh embodiment. In the liquid ejection head 8 shown in FIG. 12, a wiring 25 positioned so as to overlap with the pressure chamber row 21 in a plan view is located on the diaphragm 24. The wiring 25 has a first end face 25a facing the diaphragm 24 and a second end face 25b located on the opposite side of the first end face 25a. Further, the length L51 of the first end face 25a along the X-axis direction is smaller than the length of the second end face 25b. As a result, since it becomes difficult for the wiring 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. Further, it is possible to reduce the increase in size of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position.

[0076] Further, since the length L52 of the second end face 25b of the wiring 25 is larger than the length L51 of the first end face 25a, the cross-sectional area of the wiring 25 can be increased as compared with the case where the length L52 is less than or equal to the length L51, and the electrical resistance of the wiring 25 can be reduced.

[0077] [Eighth Embodiment] FIG. 13 is a cross-sectional view showing an example of a schematic configuration of a liquid ejection head according to an eighth embodiment. As shown in FIG. 13, in the liquid ejection head 8, the length L61 of the first end face 25a along the X-axis direction may be smaller than the length L62 of the second end face 25b along the X-axis direction. Further, the thickness L71 in the X-axis direction of the protective film 27 along the first end face 25a of the wiring 25 may be larger than the thickness L72 in the X-axis direction of the protective film 27 along the second end face 25b. Further, the length L82 in the X-axis direction of the end face 28 of the protective film 27 located on the opposite side of the first end face 25a with the wiring 25 interposed therebetween may be equal to or greater than the length L81 in the X-axis direction of the wiring 25 and the protective film 27 along the first end face 25a. Thereby, since it becomes difficult for the wiring 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. Further, it is possible to reduce the increase in size of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position.

[0078] Further, by making the thickness L71 in the X-axis direction of the protective film 27 along the first end face 25a larger than the thickness L72 in the X-axis direction of the protective film 27 along the second end face 25b, for example, even when dew condensation or the like occurs in the vicinity of the interface between the diaphragm 24 and the protective film 27, it is possible to improve the water resistance protection performance against water droplets that tend to remain at the acute angle portions, and it is possible to further improve the reliability.

[0079] [Ninth Embodiment] FIG. 14 is a cross-sectional view showing a schematic configuration of a liquid ejection head according to a ninth embodiment. As shown in FIG. 14, in the liquid ejection head 8, among the wirings 25 from the open end 29 on the pressure chamber beam 21 side of the first pressure chamber 20a, the distance from the open end 29 to the end 25a1 on the first pressure chamber 20a side of the first end face 25a facing the diaphragm 24 is defined as a radius r. When viewed in cross section along a virtual circle VC centered on the open end 29, the wiring 25 may not be located within the virtual circle VC. Thereby, since it becomes difficult for the wiring 25 to be located above the pressure chamber 20, it is possible to reduce the problem of inhibiting the displacement of the pressure chamber 20. In addition, it is possible to reduce the enlargement of the liquid ejection head 8 due to manufacturing convenience considering the possibility that the wiring 25 is displaced in the X-axis direction from a predetermined position. Furthermore, it is possible to make it difficult for problems such as aggregation of the liquid located inside the pressure chamber 20 to occur due to the electric field generated when energizing the wiring 25, and to improve the reliability of the liquid ejection head 8.

[0080] In FIG. 14, the case where the wiring 25 is located on the diaphragm 24 is shown as an example. However, for example, as shown in FIG. 5, it can also be applied to the case where the wiring 25 is located on the insulating film 26.

[0081] <Method for manufacturing a liquid ejection head> Next, an example of a method for manufacturing the liquid ejection head 8 according to the first embodiment will be described. First, a plurality of pressure chambers 20 including a first pressure chamber 20a and a second pressure chamber 20b adjacent to each other in the X-axis direction, and a pressure chamber beam 21 positioned between the first pressure chamber 20a and the second pressure chamber 20b are formed. Next, the diaphragm 24 is positioned so as to overlap from the first pressure chamber 20a to the second pressure chamber 20b in a plan view. Also, a plurality of individual electrodes 35 are respectively positioned so as to overlap the plurality of pressure chambers 20 in a plan view. Further, a plurality of wirings are electrically connected to each of the plurality of individual electrodes 35. Furthermore, an insulating film 26 is positioned between a wiring 25 positioned so as to overlap the pressure chamber beam 21 in a plan view among the plurality of wirings and the diaphragm 24. At this time, an insulating film 26 having a first surface 26a facing the diaphragm 24 and a second surface 26b facing the wiring 25, and having a length of the first surface 26a along the X-axis direction smaller than the length of the second surface 26b is prepared and positioned so as to overlap the pressure chamber beam 21 in a plan view. Thereby, the liquid ejection head 8 according to the present embodiment is obtained.

[0082] Subsequently, an example of a method for manufacturing the liquid ejection head 8 according to the seventh embodiment will be described. First, a plurality of pressure chambers 20 including a first pressure chamber 20a and a second pressure chamber 20b adjacent to each other in the X-axis direction, and a pressure chamber beam 21 positioned between the first pressure chamber 20a and the second pressure chamber 20b are formed. Next, the diaphragm 24 is positioned so as to overlap from the first pressure chamber 20a to the second pressure chamber 20b in a plan view. Also, a plurality of individual electrodes 35 are respectively positioned so as to overlap the plurality of pressure chambers 20 in a plan view. Further, a plurality of wirings are electrically connected to each of the plurality of individual electrodes 35. At this time, a wiring 25 having a first end face 25a facing the diaphragm 24 and a second end face 25b positioned on the opposite side of the first end face 25a among the plurality of wirings, and having a length of the first end face 25a along the X-axis direction smaller than the length of the second end face 25b is positioned so as to overlap the pressure chamber beam 21 in a plan view. Thereby, the liquid ejection head 8 according to the present embodiment is obtained.

[0083] Also, the liquid ejection head 8 according to other embodiments can be produced in the same manner as the liquid ejection head 8 according to each of the above-described embodiments. Note that the manufacturing method of the liquid ejection head 8 according to each of the above-described embodiments is merely an example, and there is no limitation, for example, on the order of each step.

[0084] As described above, the liquid ejection head 8 according to the embodiment includes a plurality of pressure chambers 20, a pressure chamber row 21, a diaphragm 24, a plurality of individual electrodes 35, a plurality of wirings, and an insulating film 26. The plurality of pressure chambers 20 includes a first pressure chamber 20a and a second pressure chamber 20b adjacent to each other in a first direction. The pressure chamber row 21 is located between the first pressure chamber 20a and the second pressure chamber 20b. The diaphragm 24 is located so as to overlap from the first pressure chamber 20a to the second pressure chamber 20b in a plan view. The plurality of individual electrodes 35 are respectively located so as to overlap the plurality of pressure chambers 20 in a plan view. The plurality of wirings are electrically connected to each of the plurality of individual electrodes 35. The insulating film 26 is located between the diaphragm 24 and an on-row wiring (wiring 25) that is located so as to overlap the pressure chamber row 21 in a plan view among the plurality of wirings. The insulating film 26 has a first surface 26a facing the diaphragm 24 and a second surface 26b facing the on-row wiring (wiring 25), and is located so as to overlap the pressure chamber row 21 in a plan view. The length of the first surface 26a along the first direction is smaller than the length of the second surface 26b along the first direction. Thereby, according to the liquid ejection head according to the embodiment, it is possible to reduce problems associated with displacement of the insulating film 26 and / or the wiring 25.

[0085] Further, the liquid ejection head 8 includes a plurality of pressure chambers 20, a pressure chamber row 21, a diaphragm 24, a plurality of individual electrodes 35, and a plurality of wirings. The plurality of pressure chambers 20 includes a first pressure chamber 20a and a second pressure chamber 20b adjacent to each other in a first direction. The pressure chamber row 21 is located between the first pressure chamber 20a and the second pressure chamber 20b. The diaphragm 24 is positioned so as to overlap from the first pressure chamber 20a to the second pressure chamber 20b in a plan view. The plurality of individual electrodes 35 are respectively positioned so as to overlap the plurality of pressure chambers 20 in a plan view. The plurality of wirings are electrically connected to each of the plurality of individual electrodes 35. Among the plurality of wirings, a row wiring (wiring 25) positioned so as to overlap the pressure chamber row 21 in a plan view has a first end face 25a facing the diaphragm 24 and a second end face 25b located on the opposite side of the first end face 25a. The length of the first end face 25a along the first direction is smaller than the length of the second end face 25b along the first direction. Thereby, according to the liquid ejection head according to the embodiment, it is possible to reduce the problem associated with the displacement of the wiring 25.

[0086] Further effects and modifications can be easily derived by those skilled in the art. For this reason, the broader aspects of the present invention are not limited to the specific details and representative embodiments presented and described above. Therefore, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Reference Numerals

[0087] 1 Printer 8 Liquid ejection head 14 Control unit 20 Pressure chamber 21 Pressure chamber row 24 Diaphragm 25 Wiring 26 Insulating film 27 Protective film 30 Piezoelectric element 35 Individual electrode

Claims

1. A plurality of pressure chambers including a first pressure chamber and a second pressure chamber adjacent to each other in a first direction, A pressure chamber girder positioned between the first pressure chamber and the second pressure chamber, A diaphragm positioned so as to overlap from the first pressure chamber to the second pressure chamber in a plan view, A plurality of individual electrodes respectively positioned so as to overlap the plurality of pressure chambers in a plan view, A plurality of wirings electrically connected to each of the plurality of individual electrodes, An insulating film positioned between an on-girder wiring positioned so as to overlap the pressure chamber girder in a plan view among the plurality of wirings and the diaphragm, comprising, The insulating film has a first surface facing the diaphragm and a second surface facing the on-girder wiring, and is positioned so as to overlap the pressure chamber girder in a plan view, A liquid ejection head in which a length of the first surface along the first direction is smaller than a length of the second surface along the first direction.

2. The on-girder wiring has a first end surface facing the insulating film and a second end surface positioned on the opposite side of the first end surface, The liquid ejection head according to claim 1, wherein a length of the first end surface along the first direction is smaller than a length of the second end surface along the first direction.

3. The on-girder wiring has a first end surface facing the insulating film and a second end surface positioned on the opposite side of the first end surface, The liquid ejection head according to claim 1, wherein a length of the first end surface along the first direction is larger than a length of the second end surface along the first direction.

4. Having a plurality of the on-girder wirings arranged in the first direction, Each of the on-girder wirings has a first end surface facing the insulating film and a second end surface positioned on the opposite side of the first end surface, The liquid ejection head according to claim 1, wherein a total length of the first end surfaces along the first direction is smaller than a total length of the second end surfaces along the first direction.

5. having three or more of the upper digit wirings arranged in the first direction, each of the upper digit wirings having a first end face facing the insulating film and a second end face located on the side opposite to the first end face, The total length of the first end faces along the first direction in the upper digit wirings located at both ends in the first direction is smaller than the total length of the second end faces along the first direction, the liquid ejection head according to claim 1.

6. The difference between the total length of the second end faces along the first direction and the total length of the first end faces along the first direction in one or more of the upper digit wirings located in the central portion in the first direction is smaller than the difference in the upper digit wirings located at both ends in the first direction, the liquid ejection head according to claim 5.

7. having three or more of the upper digit wirings arranged in the first direction, In one or more of the upper digit wirings located in the central portion in the first direction, the length of the first end face along the first direction is larger than the length of the second end face along the first direction, the liquid ejection head according to claim 4.

8. a plurality of pressure chambers including a first pressure chamber and a second pressure chamber adjacent to each other in a first direction, a pressure chamber digit located between the first pressure chamber and the second pressure chamber, a diaphragm positioned so as to overlap from the first pressure chamber to the second pressure chamber in a plan view, a plurality of individual electrodes respectively positioned so as to overlap the plurality of pressure chambers in a plan view, and a plurality of wirings electrically connected to each of the plurality of individual electrodes provided, Among the plurality of wirings, the upper digit wiring positioned so as to overlap the pressure chamber digit in a plan view has a first end face facing the diaphragm and a second end face located on the side opposite to the first end face, The length of the first end face along the first direction is smaller than the length of the second end face along the first direction, the liquid ejection head.

9. Further comprising a protective film covering the wiring on the digit, The thickness of the protective film in the first direction along the first end face is greater than the thickness of the protective film in the first direction along the second end face, The length of the end face of the protective film in the first direction located on the opposite side of the first end face across the wiring on the digit is equal to or greater than the length of the wiring on the digit and the protective film in the first direction along the first end face. The liquid ejection head according to claim 8.

10. Using, as a radius, the distance from the open end on the digit side of the first pressure chamber to the end on the first pressure chamber side of the first end face of the wiring on the digit facing the diaphragm, and when viewed in cross-section along a virtual circle centered on the open end, the wiring on the digit is not located within the virtual circle. The liquid ejection head according to claim 1.

11. A recording apparatus comprising the liquid ejection head according to any one of claims 1 to 10.

12. A step of forming a plurality of pressure chambers including a first pressure chamber and a second pressure chamber adjacent to each other in a first direction, and a pressure chamber digit located between the first pressure chamber and the second pressure chamber; A step of positioning a diaphragm so as to overlap from the first pressure chamber to the second pressure chamber in a plan view; A step of respectively positioning a plurality of individual electrodes so as to overlap the plurality of pressure chambers in a plan view; A step of electrically connecting a plurality of wirings to each of the plurality of individual electrodes; A step of positioning an insulating film between the diaphragm and the wiring on the digit, which is located so as to overlap the pressure chamber digit in a plan view among the plurality of wirings, the insulating film having a first surface facing the diaphragm and a second surface facing the wiring, and positioning the insulating film so as to overlap the pressure chamber digit in a plan view, wherein the length of the first surface along the first direction is smaller than the length of the second surface along the first direction. A method for manufacturing a liquid ejection head, including the above steps.

13. A step of forming a plurality of pressure chambers including a first pressure chamber and a second pressure chamber adjacent to each other in a first direction, and a pressure chamber beam located between the first pressure chamber and the second pressure chamber; A step of positioning a diaphragm so as to overlap from the first pressure chamber to the second pressure chamber in a plan view; A step of respectively positioning a plurality of individual electrodes so as to overlap the plurality of pressure chambers in a plan view; A step of electrically connecting a plurality of wirings to each of the plurality of individual electrodes, the plurality of wirings having a first end face facing the diaphragm and a second end face located on the opposite side of the first end face, and positioning a beam wiring in which the length of the first end face along the first direction is smaller than the length of the second end face along the first direction so as to overlap the pressure chamber beam in a plan view; A method for manufacturing a liquid ejection head, including the above steps.

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