JP2014097641A - Liquid jet head, liquid jet apparatus, and method of manufacturing liquid jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a nozzle 11 to be accurately aligned with a longitudinal central position of a discharge groove 6a.SOLUTION: A liquid jet head 1 of the present invention includes an actuator substrate 2 that penetrates to an undersurface LS of a substrate from a top surface US thereof and on which a plurality of long and thin discharge grooves 6a are arrayed in a face direction, and a nozzle plate that has a nozzle 11 communicating with the discharge grooves 6a and that covers an undersurface opening 8a of the discharge groove 6a. Alignment marks M1 and M2 are formed in close vicinity to an approximately central position in the longitudinal direction of the undersurface opening 8a, on the undersurface LS of the actuator substrate 2.

Description

  The present invention relates to a liquid ejecting head that discharges droplets and records on a recording medium, a liquid ejecting apparatus that uses the liquid ejecting head, and a method of manufacturing the liquid ejecting head.

  In recent years, an ink jet type liquid ejecting head has been used in which ink droplets are ejected onto recording paper or the like to record characters and figures, or a liquid material is ejected onto the surface of an element substrate to form a functional thin film. In this method, a liquid such as ink or a liquid material is guided from a liquid tank to a channel via a supply pipe, pressure is applied to the liquid filled in the channel, and the liquid is discharged from a nozzle communicating with the channel. When discharging the liquid, the liquid ejecting head or the recording medium is moved to record characters and figures, or a functional thin film having a predetermined shape is formed.

  FIG. 15 is a schematic cross-sectional view of the liquid jet head 101 described in Patent Document 1. FIG. 15A is a schematic cross-sectional view in the longitudinal direction of the groove 105 for generating a pressure wave in the liquid, and FIG. 15B is a schematic cross-sectional view in the direction orthogonal to the groove 105. FIG. 16 is a schematic plan view of the piezoelectric plate 104 viewed from the discharge side. The liquid ejecting head 101 includes a piezoelectric plate 104 made of a piezoelectric body, a cover plate 108 bonded to the surface of one side thereof, a flow path member 111 bonded to the cover plate 108, and the other side of the piezoelectric plate 104. And a nozzle plate 102 bonded to the surface of the substrate. In the piezoelectric plate 104, deep grooves 105a and shallow grooves 105b constituting the grooves 105 are alternately formed in parallel. The deep grooves 105a penetrate from one surface of the piezoelectric plate 104 to the other surface, and the shallow grooves 105b Opened on the surface of one side, the piezoelectric material is left on the other side. Side walls 106a to 106c are formed between the deep groove 105a and the shallow groove 105b. Driving electrodes 116a and 116c are formed on the side surface of the deep groove 105a, and 116b and 116d are formed on the side surface of the shallow groove 105b.

  A liquid supply port 109 and a liquid discharge port 110 are formed in the cover plate 108. The liquid supply port 109 communicates with one end of the deep groove 105a, and the liquid discharge port 110 communicates with the other end of the deep groove 105a. A liquid supply chamber 112 and a liquid discharge chamber 113 are formed in the flow path member 111, the liquid supply chamber 112 communicates with the liquid supply port 109, and the liquid discharge chamber 113 communicates with the liquid discharge port 110. The nozzle plate 102 is bonded to the lower surface of the piezoelectric plate 104 so that the nozzle 103 communicates with the deep groove 105a. Note that Patent Document 1 does not describe a positioning method between the nozzle plate 102 and the piezoelectric plate 104.

  The liquid jet head 101 is driven as follows. The liquid supplied from the supply joint 114 installed in the flow path member 111 is filled in the deep groove 105 a through the liquid supply chamber 112 and the liquid supply port 109. The liquid filled in the deep groove 105 a is further discharged to the outside from the discharge joint 115 via the liquid discharge port 110 and the liquid discharge chamber 113. When a potential difference is applied between the driving electrodes 116c and 116b and between the driving electrodes 116c and 116d, the side walls 106b and 106c are deformed in thickness, and a pressure wave is generated in the deep groove 105a, so that a droplet is discharged from the nozzle 103. Is done.

  FIG. 17 is an exploded perspective view of the ink jet head described in Patent Document 2. FIG. In the inkjet head, a laminated plate of an electrode substrate 202 and a flow path substrate 201 is installed on a frame member 225, a nozzle plate 203 is installed on the flow path substrate 201, and a filter 231 is disposed below the frame member 225. A joint member 230 is installed. Furthermore, FPC cables 221 that are electrically connected to the electrode substrate 202 and on which the driver IC 220 is mounted are installed on both sides of the frame member 225.

  Patent Document 2 describes a method of aligning the discharge chamber 206 formed in the flow path substrate 201 and the nozzle 204 formed in the nozzle plate 203. An elongated common liquid chamber 208 is formed in the flow path substrate 201, and two rows of discharge chambers 206 are formed across the common liquid chamber 208. The discharge chambers 206 in each row are elongated in a direction perpendicular to the common liquid chamber 208 and are arranged along the longitudinal direction of the common liquid chamber 208. The nozzle plate 203 is formed with two rows of nozzles 204, and each nozzle 204 is connected to the nozzle plate 203 so as to communicate with each of the two rows of discharge chambers 206 arranged along the longitudinal direction of the common liquid chamber 208. The road substrate 201 is bonded.

  Alignment holes 242 are formed on both ends of the flow path substrate 201 and on the extended line of the common liquid chamber 208 in the longitudinal direction. An alignment hole 241 is formed on the center line of the nozzles 204 in the two rows of the nozzle plate 203, and the alignment hole 241 is aligned with the alignment hole 242 on the flow path substrate 201.

JP 2011-104791 A JP 2002-96473 A

  In the case of the liquid ejecting head 101 shown in Patent Document 1, the liquid circulation type discharge groove (the deep groove 105a) through which the liquid flows in from one end and flows out from the other end is symmetric with respect to the longitudinal direction of the discharge groove. It is preferable to form. In other words, the shape of the drive wall for driving the discharge groove and the shape of the discharge groove through which the pressure wave generated by the drive wall is transmitted are formed symmetrically with respect to the center in the longitudinal direction, and the nozzle 103 is installed at the center of symmetry. Thereby, it is possible to efficiently and stably discharge droplets. Therefore, when the nozzle plate 102 is bonded to the piezoelectric plate 104, it is desirable that the nozzle 103 can be easily arranged at the center position in the longitudinal direction of the lower surface opening of the deep groove 105a. Patent Document 1 does not describe how to install the nozzle 103 at a substantially central position in the longitudinal direction of the deep groove 105a.

  The ink jet head disclosed in Patent Document 2 is provided with a diaphragm on the bottom surface of the discharge chamber 206, ink flows from one end portion in the longitudinal direction of the discharge chamber 206, and is installed near the other end portion. A droplet is discharged from the nozzle 204. Therefore, the structure is different from the discharge groove described in Patent Document 1, and it is not necessary to install the nozzle 204 at the center position in the longitudinal direction of the discharge chamber 206. In Patent Document 2, alignment between the flow path substrate 201 and the nozzle plate 203 is performed using alignment holes 241 and 242 installed at positions away from the nozzle 204 and the discharge chamber 206. For this reason, the positions of the alignment holes 241 and 242 and the nozzles 204 and the discharge chambers 206 are shifted as the ambient temperature changes. When a plastic material is used as the nozzle plate 203, it is difficult to accurately position the nozzle 204 with respect to the discharge chamber 206 because the nozzle 204 and the alignment hole 241 are separated.

  The present invention has been made in view of the above problems, and provides a liquid ejecting head, a liquid ejecting apparatus, and a method for manufacturing the same that can easily and accurately align the position of a nozzle with respect to a discharge groove. Objective.

  The liquid ejecting head of the present invention includes an actuator substrate penetrating from the upper surface to the lower surface of the substrate and having a plurality of elongated discharge grooves arranged in the surface direction, and a nozzle communicating with the discharge groove, and covers the lower surface opening of the discharge groove. A nozzle plate, and an alignment mark is formed on the lower surface of the actuator substrate in the vicinity of a substantially central position in the longitudinal direction of the lower surface opening.

  The alignment mark is a linear mark that is long in a direction orthogonal to the longitudinal direction of the lower surface opening.

  The alignment mark is a linear mark that is long in a direction parallel to the longitudinal direction of the lower surface opening.

  The alignment mark is a hole-like mark that penetrates from the upper surface to the lower surface of the actuator substrate.

  The nozzle plate is made of a light transmissive film.

  In addition, a plurality of the ejection grooves are arranged to form a groove row, and the alignment mark is formed in the vicinity of the ejection groove located at the end of the groove row.

  Further, a plurality of the alignment marks are formed in the vicinity of the ejection grooves located at both ends of the groove row.

  In the actuator substrate, the ejection grooves and the non-ejection grooves parallel to the ejection grooves are alternately arranged.

  The nozzle plate is provided with an alignment mark at a position facing the alignment mark of the actuator substrate.

  A liquid discharge chamber that communicates with one end of the ejection groove; and a liquid supply chamber that communicates with the other end of the ejection groove, and is disposed on the actuator substrate so as to partially cover the upper surface opening of the ejection groove. It was decided to provide a cover plate.

  A liquid ejecting apparatus according to an aspect of the invention includes the liquid ejecting head according to any one of the above, a moving mechanism that relatively moves the liquid ejecting head and the recording medium, and a liquid supply that supplies the liquid to the liquid ejecting head. A pipe and a liquid tank for supplying the liquid to the liquid supply pipe.

  The method of manufacturing a liquid jet head according to the present invention includes a groove forming step of forming a plurality of ejection grooves arranged in parallel with the piezoelectric substrate, and a bottom surface of the piezoelectric substrate in the longitudinal direction of the lower surface opening where the ejection grooves open. An alignment mark forming step for forming an alignment mark close to a substantially central position and a nozzle plate installation step for installing a nozzle plate on the lower surface of the piezoelectric substrate are provided.

  An electrode forming step of forming an electrode on the piezoelectric substrate; a cover plate installing step of installing a cover plate on the upper surface of the piezoelectric substrate; and a lower surface of the piezoelectric substrate is ground, and a plurality of the ejection grooves are formed on the upper surface. And a piezoelectric substrate grinding step for penetrating from the bottom to the bottom surface.

  The alignment mark forming step is a step performed after the piezoelectric substrate grinding step.

  Further, the alignment mark forming step is a step of forming a groove that is parallel to the longitudinal direction of the plurality of discharge grooves and shallower than the discharge grooves.

  A liquid ejecting head according to the present invention includes an actuator substrate penetrating from the upper surface to the lower surface of the substrate and having a plurality of elongated discharge grooves arranged in the surface direction, and a nozzle plate communicating with the discharge grooves, and covering a lower surface opening of the discharge grooves An alignment mark is formed on the lower surface of the actuator substrate in the vicinity of a substantially central position in the longitudinal direction of the lower surface opening. Thereby, the nozzle of a nozzle plate can be correctly aligned with the center position of the longitudinal direction of a discharge groove.

FIG. 3 is an explanatory diagram of a liquid ejecting head according to the first embodiment of the invention. FIG. 6 is a schematic plan view of a discharge side from which a nozzle plate of a liquid jet head according to a second embodiment of the invention is removed. FIG. 10 is an explanatory diagram of a liquid jet head according to a third embodiment of the present invention. FIG. 10 is an explanatory diagram of a liquid jet head according to a fourth embodiment of the present invention. 10 is a flowchart of a manufacturing process of a liquid jet head according to a fifth embodiment of the present invention. It is explanatory drawing of the groove | channel formation process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the conductor deposition process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the electrode formation process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the cover plate installation process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the piezoelectric substrate grinding process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the alignment mark formation process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the nozzle plate installation process of the liquid jet head which concerns on 5th embodiment of this invention. It is explanatory drawing of the manufacturing method of the liquid jet head which concerns on 6th embodiment of this invention. FIG. 10 is a schematic perspective view of a liquid ejecting apparatus according to a seventh embodiment of the invention. It is a cross-sectional schematic diagram of a conventionally known liquid jet head. FIG. 6 is a schematic plan view when a piezoelectric plate of a conventionally known liquid jet head is viewed from the discharge side. It is a disassembled perspective explanatory drawing of a conventionally well-known inkjet head.

(First embodiment)
FIG. 1 is an explanatory diagram of a liquid jet head 1 according to the first embodiment of the present invention. 1A is a schematic sectional view of the ejection groove 6a, FIG. 1B is a schematic sectional view of the non-ejection groove 6b, and FIG. 1C is orthogonal to the longitudinal direction of the center of the ejection groove 6a. FIG. 1D is a schematic plan view of a lower surface LS obtained by removing the nozzle plate 4 from the actuator substrate 2. In FIG. 1D, the nozzle 11 is indicated by a broken line for easy understanding.

  The liquid ejecting head 1 has a stacked structure of an actuator substrate 2, a cover plate 3 installed on the upper surface US, and a nozzle plate 4 installed on the lower surface LS of the actuator substrate 2. The actuator substrate 2 penetrates from the upper surface US to the lower surface LS, and a plurality of elongated ejection grooves 6a are arranged in the surface direction. The cover plate 3 includes a liquid discharge chamber 10 that communicates with one end of the discharge groove 6a and a liquid supply chamber 9 that communicates with the other end of the discharge groove 6a. The nozzle plate 4 has a nozzle 11 communicating with the ejection groove 6a, and is installed on the lower surface LS of the actuator substrate 2 so as to cover the lower surface opening 8 of the ejection groove 6a. Then, alignment marks M1 and M2 are formed on the lower surface LS of the actuator substrate 2 in the vicinity of a substantially central position in the longitudinal direction of the lower surface opening 8 of the ejection groove 6a. Thereby, the nozzle 11 of the nozzle plate 4 can be accurately aligned with the central position in the longitudinal direction of the ejection groove 6a.

  This will be described more specifically. In the actuator substrate 2, ejection grooves 6a and non-ejection grooves 6b are alternately arranged in parallel. The discharge groove 6 a is formed from the front side of the outer peripheral end LE on one side of the actuator substrate 2 to the front side of the outer peripheral end RE on the other side and before the end portion of the cover plate 3. The non-ejection groove 6 b is formed from the front side of the outer peripheral end LE on one side of the actuator substrate 2 to the outer peripheral end RE on the other side. The non-ejection groove 6b is formed with a raised bottom 15 at the other end. The non-ejection groove 6b penetrates from the upper surface US of the actuator substrate 2 to the lower surface LS like the ejection groove 6a. An upper surface opening 7 of the ejection groove 6a and an upper surface opening 7 of the non-ejection groove 6b are alternately opened in parallel on the upper surface US of the actuator substrate 2, and the lower surface opening 8a of the ejection groove 6a and the non-ejection are disposed on the lower surface LS of the actuator substrate 2. The lower surface openings 8b of the grooves 6b are alternately opened in parallel. The alignment marks M1 and M2 are linear marks that are long in the direction (x direction) perpendicular to the longitudinal direction (y direction) of the lower surface opening 8a of the ejection groove 6a, and are substantially at the center in the longitudinal direction of the lower surface opening 8a. It is installed close to the ejection groove 6a (lower surface opening 8a) near the end in the arrangement direction (x direction) of the grooves 6.

  In this embodiment, the lower surface opening 8a of the ejection groove 6a and the lower surface opening 8b of the non-ejection groove 6b have the same shape, but the lower surface opening 8a and the lower surface opening 8b are different in shape or shifted in the longitudinal direction (y direction). The formation positions may be different. Even in this case, the alignment marks M1 and M2 are formed so as to be close to a substantially central position in the longitudinal direction with respect to the lower surface opening 8a of the ejection groove 6a. In the present embodiment, the raised bottom 15 is formed at the other end of the non-ejection groove 6b. However, the present invention is not limited to this non-ejection groove 6b, and the non-ejection groove 6b has the same shape as the ejection groove 6a. Alternatively, the actuator substrate 2 may be left without passing the non-ejection groove 6b through the lower surface LS of the actuator substrate 2.

  A common electrode 12a having a depth that does not reach the bottom surface of the discharge groove 6a, that is, the nozzle plate 4, is formed on both side surfaces of the wall 5 sandwiching the discharge groove 6a, and a common terminal 16a formed on the upper surface US of the other end. Is electrically connected. Similarly, on both sides of the wall 5 sandwiching the non-ejection groove 6b, the bottom surface of the non-ejection groove 6b, that is, the active electrode 12b having a depth that does not reach the nozzle plate 4, is formed on the upper surface US of the other end. Is electrically connected to the active terminal 16b. The active electrodes 12b formed on both side surfaces of the non-ejection groove 6b are electrically separated from each other. The active electrode 12b is formed above the upper surface BP of the raised bottom portion 15. Accordingly, the two active electrodes 12b facing each other inside the non-ejection groove 6b are prevented from being electrically connected via the inclined surface 22 at one end portion. Similarly, at the other end, the two active electrodes 12b facing each other inside the non-ejection groove 6b are prevented from being electrically connected via the upper surface BP.

  A non-ejection groove adjacent to the common terminal 16a electrically connected to the common electrode 12a and the active terminal 16b electrically connected to the active electrode 12b is formed on the upper surface US near the outer peripheral end RE on the other side of the actuator substrate 2. A wiring 16c that electrically connects the active electrode 12b formed on 6b is provided. The common terminal 16a and the active terminal 16b are lands connected to wiring electrodes of a flexible substrate (not shown). The active terminal 16b is electrically connected to the active electrode 12b formed on the side surface of the one wall 5 facing the non-ejection groove 6b of the two walls 5 sandwiching the ejection groove 6a. The active terminal 16b is further electrically connected to an active electrode 12b formed on a side surface facing the non-ejection groove 6b of the other wall 5 via a wiring 16c formed along the outer peripheral end RE on the other side. The

  In the cover plate 3, a liquid discharge chamber 10 is formed in front of the outer peripheral end on one side, and a liquid supply chamber 9 is formed in front of the outer peripheral end on the other side. Further, a first slit 14 a is formed at the bottom of the liquid discharge chamber 10, and a second slit 14 b is formed at the bottom of the liquid supply chamber 9. The cover plate 3 is adhered to the upper surface US of the actuator substrate 2 with an adhesive so as to partially cover the ejection grooves 6a and the non-ejection grooves 6b and to expose the common terminals 16a and the active terminals 16b. The first slit 14a communicates with one end of the ejection groove 6a, and the second slit 14b communicates with the other end of the ejection groove 6a. The non-ejection groove 6 b does not communicate with the liquid supply chamber 9 and the liquid discharge chamber 10. That is, the upper surface opening 7 of the non-ejection groove 6 b is covered with the cover plate 3.

  The nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2 via an adhesive so that each nozzle 11 is arranged on a straight line connecting the alignment marks M1 and M2. The nozzle 11 formed in the nozzle plate 4 communicates with the ejection groove 6 a, and the lower surface opening 8 b of the non-ejection groove 6 b is closed by the nozzle plate 4. By using a light transmissive film as the nozzle plate 4, the nozzle 11 can be easily aligned with the alignment marks M1 and M2. Further, in the case of the nozzle plate 4 that does not transmit light, an alignment opening is formed at a position close to the nozzle at the end on the nozzle row in which the nozzles 11 are arranged, and from this opening to the lower surface LS. The actuator substrate 2 and the nozzle plate 4 may be aligned by visually recognizing the formed alignment marks M1 and M2.

  The actuator substrate 2 is made of PZT ceramic that has been polarized in a direction perpendicular to the upper surface. If PZT ceramics, which is the same material as the actuator substrate 2, is used for the cover plate 3, the thermal expansion is equal, so that warpage and deformation with respect to temperature changes do not occur. In addition, a material having a thermal expansion coefficient similar to that of PZT ceramics is preferable even with a different material. The nozzle plate 4 uses a light transmissive polyimide film. Here, the thickness of the cover plate 3 is preferably 0.3 mm to 1.0 mm, and the thickness of the nozzle plate 4 is preferably 0.01 mm to 0.1 mm. If the cover plate 3 is thinner than 0.3 mm, the strength is lowered, and if it is thicker than 1.0 mm, it takes time to process the liquid supply chamber 9, the liquid discharge chamber 10, and the first and second slits 14 a and 14 b, The cost increases due to the increase in materials. If the nozzle plate is made thinner than 0.01 mm, the strength is lowered. If the nozzle plate is made thicker than 0.1 mm, vibration is transmitted to adjacent nozzles, and crosstalk is likely to occur.

  PZT ceramics has a Young's modulus of 58.48 GPa, and polyimide has a Young's modulus of 3.4 GPa. Accordingly, the cover plate 3 covering the upper surface US of the actuator substrate 2 has higher rigidity than the nozzle plate 4 covering the lower surface LS. The cover plate 3 preferably has a Young's modulus not lower than 40 GPa, and the nozzle plate 4 preferably has a Young's modulus in the range of 1.5 GPa to 30 GPa. When the Young's modulus is less than 1.5 GPa, the nozzle plate 4 is easily scratched when it contacts the recording medium, and the reliability is lowered. When the nozzle plate 4 exceeds 30 GPa, vibration is transmitted to adjacent nozzles and crosstalk occurs. It becomes easy.

  The liquid jet head 1 is driven as follows. The liquid supplied to the liquid supply chamber 9 flows into the discharge groove 6a through the second slit 14b, and further flows out from the discharge groove 6a into the liquid discharge chamber 10 through the first slit 14a. When a drive signal is applied to the common terminal 16a and the active terminal 16b, both walls sandwiching the ejection groove 6a are subjected to thickness-slip deformation, and a pressure wave is generated in the liquid filled in the ejection groove 6a. By this pressure wave, droplets are ejected from the nozzle 11 and recorded on the recording medium. By separating the common electrode 12 a and the active electrode 12 b from the bottom surface of the groove 6, that is, the nozzle plate 4, the pressure wave induced in the liquid is stabilized and the droplets can be ejected stably. The functions of the liquid supply chamber 9 and the liquid discharge chamber 10 may be reversed.

  As described above, since the alignment marks M1 and M2 are provided on the lower surface LS of the actuator substrate 2, the nozzle 11 can be aligned at a substantially central position in the longitudinal direction of the lower surface opening 8a of the ejection groove 6a. It is possible to provide the liquid ejecting head 1 capable of ejecting droplets stably and efficiently.

(Second embodiment)
FIG. 2 is a schematic plan view on the discharge side where the nozzle plate 4 is removed from the actuator substrate 2 of the liquid jet head 1 according to the second embodiment of the present invention. The difference from the first embodiment is that the alignment marks M1 and M2 are formed in parallel with the longitudinal direction of the lower surface opening 8a, and other configurations are the same as in the first embodiment. In FIG. 2, the nozzle 11 is indicated by a broken line for easy understanding. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 2, the alignment marks M1 and M2 are linear marks that are long in a direction parallel to the longitudinal direction of the lower surface opening 8a. The nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2 with an adhesive so that each nozzle 11 is arranged in a straight line connecting the centers of the alignment marks M1 and M2. Thereby, the nozzle 11 of the nozzle plate 4 can be accurately aligned with the central position in the longitudinal direction of the ejection groove 6a. Since other configurations and features are the same as those of the first embodiment, description thereof is omitted.

(Third embodiment)
FIG. 3 is an explanatory diagram of the liquid jet head 1 according to the third embodiment of the present invention. FIG. 3A is a schematic cross-sectional view of the position of the nozzle 11, and FIG. 3B is a schematic plan view on the discharge side where the nozzle plate 4 is removed from the actuator substrate 2. In FIG. 3B, the nozzle 11 is indicated by a broken line for easy understanding. The difference from the first embodiment is that the alignment marks M1 and M2 are holes formed through the actuator substrate 2, and the other configurations are the same as in the first embodiment. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 3, the alignment marks M1 and M2 are formed in the vicinity of both ends of the groove row where the discharge grooves 6a and the non-discharge grooves 6b are alternately arranged, and penetrate from the upper surface US of the actuator substrate 2 to the lower surface LS. It consists of hole-shaped marks. The nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2 with an adhesive so that each nozzle 11 is arranged in a straight line connecting the centers of the alignment marks M1 and M2. Thereby, the nozzle 11 of the nozzle plate 4 can be accurately aligned with the central position in the longitudinal direction of the ejection groove 6a. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

(Fourth embodiment)
FIG. 4 is an explanatory diagram of the liquid jet head 1 according to the fourth embodiment of the present invention. The difference from the first embodiment is that the alignment marks N1 and N2 are also formed on the nozzle plate 4 so that the nozzle plate 4 can be accurately aligned with respect to the actuator substrate 2. Other configurations are the same as those of the first embodiment. The same portions or portions having the same function are denoted by the same reference numerals.

  FIG. 4 is a schematic plan view in which the lower surface LS of the actuator substrate 2 and the nozzle plate 4 are shifted in order to facilitate understanding. On the lower surface LS of the actuator substrate 2, lower surface openings 8a of the ejection grooves 6a and lower surface openings 8b of the non-ejection grooves 6b are alternately opened in parallel. The alignment marks M1 and M2 are linear marks that are long in the direction (x direction) perpendicular to the longitudinal direction (y direction) of the lower surface opening 8a of the ejection groove 6a, and are substantially at the center in the longitudinal direction of the lower surface opening 8a. It is installed close to the ejection groove 6a (lower surface opening 8a) near the end in the arrangement direction (x direction) of the grooves 6.

  The nozzle plate 4 is light transmissive, is close to the nozzle 11 near the end in the arrangement direction (x direction) in which the plurality of nozzles 11 are arranged, and faces the alignment marks M1 and M2 formed on the lower surface LS. Alignment marks N1 and N2 are provided at the positions to be operated. The alignment marks N1 and N2 can be formed by the same method as processing the nozzle 11 when forming the nozzle 11. Thus, the nozzle plate 4 can be aligned and joined to the actuator substrate 2 with high accuracy so that the alignment marks M1 and M2 of the actuator substrate 2 are aligned with the alignment marks N1 and N2 of the nozzle plate 4. it can.

  Here, the alignment marks M1, M2, N1, and N2 are not limited to linear marks, but may be quadrangular, + -shaped, ◯ -shaped, or other shapes. Further, if the alignment marks N1 and N2 are formed as through holes in the same manner as the nozzle 11, even the nozzle plate 4 that does not transmit light can be easily aligned.

  In the first to fourth embodiments described above, the ejection grooves 6a and the non-ejection grooves 6b are alternately arranged on the actuator substrate 2 to which the nozzle plate 4 is bonded, and two alignment marks M1 are formed on the lower surface LS. However, the present invention is not limited to these embodiments. The following modifications are also included in the scope of the present invention.

(Modification 1)
In the above embodiment, the ejection grooves 6a and the non-ejection grooves 6b are arranged alternately. However, all the grooves except the grooves located at both ends of the array can be used as the ejection grooves 6a. In this case, the nozzle 11 may be formed at a position corresponding to the ejection groove 6a. Thereby, the nozzle 11 of the nozzle plate 4 can be accurately aligned with the central position in the longitudinal direction of the ejection groove 6a.

(Modification 2)
In the implementation liquid, the alignment marks M1 and M2 are disposed on both ends of the lower surface LS of the actuator substrate 2 in the arrangement direction of the grooves 6 (x direction). Can only be. Even in this case, the nozzle 11 of the nozzle plate 4 can be accurately aligned with the center position in the longitudinal direction of the groove 6.

(Fifth embodiment)
5 to 12 are explanatory diagrams of the method of manufacturing the liquid jet head 1 according to the fifth embodiment of the invention. FIG. 5 is a flowchart of the manufacturing process of the liquid jet head 1 according to the fifth embodiment of the present invention, and FIGS. 6 to 12 are explanatory diagrams of each process. Hereinafter, the manufacturing method of the liquid jet head 1 will be described in detail with reference to FIGS. 5 and 6 to 12. The same portions or portions having the same function are denoted by the same reference numerals.

  First, in the resin film forming step S01, a photosensitive resin film is placed on the upper surface US of the piezoelectric substrate. PZT ceramics can be used as the piezoelectric substrate. It can be formed by applying a resist film as the resin film. Moreover, a photosensitive resin film can be installed. Next, in a pattern forming step S02, exposure / development is performed to form a resin film pattern. The resin film in the region where the electrode is formed later is removed, and the resin film is left in the region where the electrode is not formed. This is because the electrode is patterned later by a lift-off method.

  FIG. 6 is an explanatory diagram of the groove forming step S1. FIG. 6A is a schematic cross-sectional view showing a state in which the groove 6 is formed by grinding using the dicing blade 21, and FIG. 6B is a schematic cross-sectional view of the discharge groove 6a. FIG. Is a schematic cross-sectional view of the non-ejection groove 6b, and FIG. 6D is a schematic top view of the piezoelectric substrate 19 in which the groove 6 is formed. As shown in FIG. 6, in the groove forming step S <b> 1, a plurality of grooves 6 parallel to the piezoelectric substrate 19 are formed. The groove 6 includes a discharge groove 6a and a non-discharge groove 6b, and the discharge grooves 6a and the non-discharge grooves 6b are alternately formed in parallel. The dicing blade 21 is lowered to one end portion of the groove 6, moved horizontally, and raised at the other end portion. The dicing blade 21 has a depth that does not reach the lower surface of the piezoelectric substrate 19, and is ground deeper than the broken line Z that represents the depth of the ejection grooves 6a and the non-ejection grooves 6b. Further, the non-ejection groove 6 b is formed by raising the other end to the outer peripheral end of the piezoelectric substrate 19 so as to be shallow and forming the raised bottom 15. A patterned resin film 20 is formed on the upper surface of the piezoelectric substrate 19.

  By grinding deeper than the broken line Z, which is the final depth of the ejection grooves 6a and the non-ejection grooves 6b, the width W in the longitudinal direction of the inclined surface 22 can be reduced. That is, since grinding is performed using the dicing blade 21, the outer peripheral shape of the dicing blade 21 is transferred to one end of the ejection groove 6a, the other end, and the one end of the non-ejection groove 6b. Is done. For example, when a groove having a depth of 360 μm is formed by using a 2-inch dicing blade 21, the inclined surface 22 at the end has a width in the longitudinal direction of about 4 mm. On the other hand, if a groove having a depth of 590 μm is formed using the same dicing blade 21, the width W up to a depth of 360 μm can be reduced by half to about 2 mm. This can be shortened by a total of 4 mm at the two ends of the one side and the other side, and the number of piezoelectric substrates 19 taken from the piezoelectric wafer can be increased.

  FIG. 7 is an explanatory diagram of the conductor deposition step S20. In the conductor deposition step S20, the conductor 24 is deposited on the upper surface US of the piezoelectric substrate 19 from the angles + θ and −θ inclined in the direction perpendicular to the longitudinal direction of the groove 6 with respect to the normal line of the upper surface US. . In the present embodiment, the conductor 24 is deposited to a depth of approximately d / 2 of the depth d from the upper surface US of the wall 5 to the broken line Z. Since the upper surface BP of the raised bottom portion 15 is located below the lower end E (see FIG. 9), the conductor 24 is not deposited on the upper surface BP. On the other hand, the conductor 24 is deposited on the inclined surface formed at the other end of the ejection groove 6a in a region shallower than the depth d / 2 in the same manner as the upper surface US. The conductor 24 may be formed shallower than the broken line Z, which is the final depth of the groove 6, and deeper than d / 2.

  FIG. 8 is an explanatory diagram of the electrode formation step S2. In the electrode forming step S2, the conductor 24 is patterned to form the common electrode 12a and the active electrode 12b. That is, the conductor 24 deposited on the upper surface is removed by a lift-off method for removing the resin film 20. Thereby, the conductor 24 deposited on both side surfaces of the wall 5 is separated to form the common electrode 12a and the active electrode 12b. In the electrode formation step S2, the common terminal 16a and the active terminal 16b are formed at the same time (see FIG. 9). In the electrode formation step S2, the common terminal 16a, the active terminal 16b, and the wiring 16c are formed at the same time (see FIG. 6D). Thereby, the active electrodes 12b formed on both side surfaces of the non-ejection groove 6b are electrically separated from each other, and the common electrodes 12a formed on both side surfaces of the ejection groove 6a are electrically connected. Furthermore, the common electrode 12a is electrically connected to the common terminal 16a, and the active electrode 12b is electrically connected to the active terminal 16b. The active terminal 16b is electrically connected to the active electrode 12b formed on the side surface of the one wall 5 facing the non-ejection groove 6b of the two walls 5 sandwiching the ejection groove 6a. The active terminal 16b is further electrically connected to an active electrode 12b formed on a side surface facing the non-ejection groove 6b of the other wall 5 via a wiring 16c formed along the outer peripheral end RE on the other side. The

  Thereby, the active electrodes 12b formed on both side surfaces of the non-ejection groove 6b are electrically separated from each other, and the common electrodes 12a formed on both side surfaces of the ejection groove 6a are electrically connected. Note that the lower end E of the common electrode 12a and the active electrode 12b formed by the oblique deposition method is set to about ½ of the final depth d of the ejection groove 6a and the non-ejection groove 6b. Good. Even in such a case, the broken line Z that is the final depth of the ejection grooves 6a and the non-ejection grooves 6b is not reached. By separating the common electrode 12a and the active electrode 12b from the broken line Z, which is the bottom surface of the ejection grooves 6a and the non-ejection grooves 6b, it is possible to eject liquid droplets stably.

  FIG. 9 is an explanatory diagram of the cover plate installation step S3. FIG. 9A is a schematic sectional view in the longitudinal direction of the ejection groove 6a, and FIG. 9B is a schematic sectional view in the longitudinal direction of the non-ejection groove 6b. As shown in FIG. 9, in the cover plate installation step S <b> 3, the cover plate 3 is installed above the piezoelectric substrate 19. The cover plate 3 has a liquid discharge chamber 10 formed on one side and a liquid supply chamber 9 formed on the other side. The first slit 14 a penetrating from the liquid discharge chamber 10 to the back surface on the opposite side and the liquid supply chamber 9 A second slit 14b penetrating the back surface on the opposite side is formed. The liquid discharge chamber 10 communicates with one end of the ejection groove 6a via the first slit 14a, and the liquid supply chamber 9 communicates with the other end of the ejection groove 6a via the second slit 14b. The non-ejection groove 6 b is closed at the upper surface opening 7 by the cover plate 3 and does not communicate with the liquid discharge chamber 10 and the liquid supply chamber 9.

  FIG. 10 is an explanatory diagram of the piezoelectric substrate grinding step S4. 10A is a schematic cross-sectional view in the longitudinal direction of the ejection groove 6a, and FIG. 10B is a schematic cross-sectional view in the longitudinal direction of the non-ejection groove 6b. As shown in FIG. 10, in the piezoelectric substrate grinding step S4, the piezoelectric substrate 19 on the side opposite to the side where the grooves 6 are formed is ground, and the grooves 6 are penetrated from the upper surface US to the lower surface LS. Form. The back surface of the piezoelectric substrate 19 is ground to the broken line Z that is the final depth of the groove 6. The upper surface US of each wall 5 is fixed by the cover plate 3, and the piezoelectric substrate 19 is left at one end of each groove 6 and the other end including the raised bottom 15, so that during grinding, Breakage can be prevented.

  FIG. 11 is an explanatory diagram of the alignment mark forming step S5 and is a schematic plan view seen from the discharge side of the actuator substrate 2. FIG. In the alignment mark forming step S5, after the piezoelectric substrate grinding step S4, alignment marks M1 and M2 composed of linear marks that are long in the direction orthogonal to the lower surface opening 8a that opens to the lower surface LS of the actuator substrate 2 are formed. . Specifically, the alignment marks M1 and M2 are formed in the vicinity of both ends of the lower surface LS in the groove row direction (x direction) and at a substantially central position in the longitudinal direction (y direction) of the lower surface opening 8a. The alignment marks M1 and M2 can be formed linearly in a direction perpendicular to the longitudinal direction (y direction) of the lower surface opening 8a by a hard cutter or a dicing blade.

  FIG. 12 is an explanatory diagram of the nozzle plate installation step S6. 12A is a schematic diagram immediately before the nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2, and FIG. 12B is a discharge groove after the nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2. FIG. 12C is a schematic cross-sectional view in the longitudinal direction of the non-ejection groove 6b after the nozzle plate 4 is bonded to the lower surface LS of the actuator substrate 2. FIG. As shown in FIG. 12, in the nozzle plate installation step S6, the nozzle plate 4 is placed on the lower surface LS of the actuator substrate 2 with an adhesive so that the nozzle row composed of the nozzles 11 coincides with the alignment marks M1 and M2. Glue. As a result, the lower surface opening 8b of the non-ejection groove 6b is closed, and each nozzle 11 communicates with the corresponding longitudinal center of the lower surface opening 8a, that is, at the substantially central position of the ejection groove 6a.

  As described above, since the alignment marks M1 and M2 are close to the ejection grooves 6a and the nozzles 11, even when the environmental temperature changes or when the nozzle plate 4 made of a plastic material is used, the nozzles 11 are placed in the ejection grooves. It can be easily installed at a substantially central position of 6a.

  In addition, the piezoelectric substrate 19 can use a piezoelectric body for the part of the wall 5 which partitions at least each groove | channel 6, and can make it an insulator which consists of a non-piezoelectric body in another area | region. Further, the lower surface opening 8a of the ejection groove 6a and the lower surface opening 8b of the non-ejection groove 6b do not have to have the same shape, and the non-ejection groove 6b leaves the piezoelectric substrate 19 at the bottom and eliminates the lower surface opening 8b. Also good. Further, the nozzle plate 4 does not have to be a single layer, and can be composed of a plurality of thin film layers made of different materials. In the present embodiment, the common electrode 12a, the active electrode 12b, the common terminal 16a, and the active terminal 16b are patterned by the lift-off method, but the present invention is not limited to this. For example, after the conductor 24 is formed on the upper surface US of the piezoelectric substrate 19 and the side surface of the wall 5 by the oblique deposition method in the conductor deposition step S20, the common electrode 12a, the active electrode 12b, and the common terminal 16a are formed by photolithography and etching methods. A pattern of the active terminals 16b may be formed. Further, the piezoelectric substrate grinding step S4 can be omitted. That is, the thickness of the piezoelectric substrate 19 is set to about the final depth of the groove 6, and in the groove forming step S 1 shown in FIG. 6, the dicing blade 21 is deeply cut so as to penetrate the lower surface of the piezoelectric substrate 19. The groove 6 may be formed so that the lower surface opening 8 is formed on the lower surface 19 and the raised bottom 15 is left at the same time.

(Sixth embodiment)
FIG. 13 is an explanatory diagram of a method for manufacturing the liquid jet head 1 according to the sixth embodiment of the invention. FIG. 13A shows a state in which the alignment grooves M1 ′ and M2 ′ are formed at the end of the groove 6 in the column direction, which is substantially the center in the longitudinal direction of the discharge groove 6a and is perpendicular to the longitudinal direction. FIG. 13B is a schematic cross-sectional view of the piezoelectric substrate 19, and FIG. 13B is a schematic plan view of the lower surface LS of the actuator substrate 2. The difference from the fifth embodiment is that shallow grooves are formed in the direction parallel to the longitudinal direction of the groove 6 as the alignment grooves M1 ′ and M2 ′, and the other points are the same as in the fifth embodiment. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 13A, in the alignment mark formation step S5, both end portions in the column direction of the grooves 6 are formed before and after the groove formation step S1 in which the discharge grooves 6a and the non-discharge grooves 6b are alternately formed in parallel. The alignment grooves M1 ′ and M2 ′ are formed in The alignment grooves M1 ′ and M2 ′ are parallel to the longitudinal direction of the discharge groove 6a and are shallower than the discharge groove 6a by using a dicing blade for forming the discharge groove 6a or the non-discharge groove 6b. It is slightly deeper than the broken line Z, which is the final depth of the groove 6a, and is formed at a substantially central position in the longitudinal direction of the discharge groove 6a.

  Next, as shown in FIG. 13B, the lower surface openings 8a and 8b are formed in the lower surface LS by grinding the lower surface of the piezoelectric substrate 19 in the piezoelectric substrate grinding step S4. Thereby, alignment grooves M1 'and M2' are exposed at both ends in the column direction. Therefore, the alignment mark formation step S5 can be performed in substantially the same step as the groove formation step S1, so that the manufacturing steps are hardly increased.

  In this embodiment, the alignment grooves M1 ′ and M2 ′ are formed in parallel with the longitudinal direction of the groove 6 before and after the groove forming step S1, but instead, before and after the piezoelectric substrate grinding step S4. In addition, a hole-like mark penetrating from the upper surface to the lower surface of the piezoelectric substrate 19 may be formed in the vicinity of the end in the row direction of the grooves 6 and at a substantially central position in the longitudinal direction of the ejection grooves 6a.

(Seventh embodiment)
FIG. 14 is a schematic perspective view of a liquid ejecting apparatus 30 according to the seventh embodiment of the present invention. The liquid ejecting apparatus 30 includes a moving mechanism 40 that reciprocates the liquid ejecting heads 1 and 1 ′, and a flow path unit that supplies the liquid to the liquid ejecting heads 1 and 1 ′ and discharges the liquid from the liquid ejecting heads 1 and 1 ′. 35, 35 ', liquid pumps 33, 33' for supplying liquid to the flow path portions 35, 35 ', and liquid tanks 34, 34'. Each liquid jet head 1, 1 ′ includes a plurality of head chips, each head chip includes a plurality of channels, and ejects droplets from nozzles communicating with the respective channels. As the liquid pumps 33 and 33 ′, either or both of a supply pump that supplies the liquid to the flow path portions 35 and 35 ′ and a discharge pump that discharges the liquid are installed. In addition, a pressure sensor and a flow rate sensor (not shown) may be installed to control the liquid flow rate. The liquid ejecting heads 1 and 1 ′ use the first embodiment described above. The liquid ejecting heads 1 and 1 ′ use any one of the first to fourth embodiments already described.

  The liquid ejecting apparatus 30 includes a pair of conveying units 41 and 42 that convey a recording medium 44 such as paper in the main scanning direction, liquid ejecting heads 1 and 1 ′ that eject liquid onto the recording medium 44, and a liquid ejecting head. 1, 1 ′ carriage unit 43, liquid tanks 34, 34 ′ and liquid pumps 33, 33 ′ that supply the liquid stored in the liquid tanks 34, 34 ′ to the flow path portions 35, 35 ′, the liquid jet head 1, And a moving mechanism 40 that scans 1 ′ in the sub-scanning direction orthogonal to the main scanning direction. A control unit (not shown) controls and drives the liquid ejecting heads 1, 1 ′, the moving mechanism 40, and the conveying units 41 and 42.

  The pair of conveying means 41 and 42 includes a grid roller and a pinch roller that extend in the sub-scanning direction and rotate while contacting the roller surface. A grid roller and a pinch roller are moved around the axis by a motor (not shown), and the recording medium 44 sandwiched between the rollers is conveyed in the main scanning direction. The moving mechanism 40 couples a pair of guide rails 36 and 37 extending in the sub-scanning direction, a carriage unit 43 slidable along the pair of guide rails 36 and 37, and the carriage unit 43 to move in the sub-scanning direction. An endless belt 38 is provided, and a motor 39 that rotates the endless belt 38 via a pulley (not shown) is provided.

  The carriage unit 43 mounts a plurality of liquid jet heads 1, 1 ′, and ejects, for example, four types of liquid droplets of yellow, magenta, cyan, and black. The liquid tanks 34 and 34 'store liquids of corresponding colors and supply them to the liquid jet heads 1 and 1' via the liquid pumps 33 and 33 'and the flow path portions 35 and 35'. Each liquid ejecting head 1, 1 ′ ejects droplets of each color according to the drive signal. An arbitrary pattern is recorded on the recording medium 44 by controlling the timing at which liquid is ejected from the liquid ejecting heads 1, 1 ′, the rotation of the motor 39 that drives the carriage unit 43, and the conveyance speed of the recording medium 44. I can.

  In this embodiment, the moving mechanism 40 moves the carriage unit 43 and the recording medium 44 to perform recording, but instead, the carriage unit is fixed and the moving mechanism is the recording medium. It may be a liquid ejecting apparatus that records the image by moving it two-dimensionally. That is, the moving mechanism may be any mechanism that relatively moves the liquid ejecting head and the recording medium.

DESCRIPTION OF SYMBOLS 1 Liquid ejecting head 2 Actuator board | substrate 3 Cover plate 4 Nozzle plate 5 Wall 6 Groove, 6a Discharge groove, 6b Non-discharge groove 7 Upper surface opening 8, 8a, 8b Lower surface opening,
DESCRIPTION OF SYMBOLS 9 Liquid supply chamber 10 Liquid discharge chamber 11 Nozzle 12 Drive electrode, 12a Common electrode, 12b Active electrode 14 Slit, 14a First slit, 14b Second slit 15 Raised bottom part 16a Common terminal, 16b Active terminal 19 Piezoelectric substrate 20 Resin film 21 Dicing blade 22 Inclined surface 24 Conductor US Upper surface, LS lower surface, BP upper surface, LE One outer peripheral end, RE The other outer peripheral end M, M1, M2, N1, N2 Alignment marks M1 ′, M2 ′ Alignment Groove

Claims (15)

An actuator substrate penetrating from the upper surface to the lower surface of the substrate, and a plurality of elongated ejection grooves arranged in the surface direction;
A nozzle plate having a nozzle communicating with the discharge groove, and covering a lower surface opening of the discharge groove;
A liquid jet head in which an alignment mark is formed on the lower surface of the actuator substrate in the vicinity of a substantially central position in the longitudinal direction of the lower surface opening.   The liquid ejecting head according to claim 1, wherein the alignment mark is a linear mark that is long in a direction orthogonal to a longitudinal direction of the lower surface opening.   The liquid ejecting head according to claim 1, wherein the alignment mark is a linear mark that is long in a direction parallel to a longitudinal direction of the lower surface opening.   The liquid ejecting head according to claim 1, wherein the alignment mark is a hole-shaped mark that penetrates from the upper surface to the lower surface of the actuator substrate.   The liquid ejecting head according to claim 1, wherein the nozzle plate is made of a light transmissive film.   6. The discharge groove according to claim 1, wherein a plurality of the discharge grooves are arranged to form a groove row, and the alignment mark is formed close to the discharge groove located at an end of the groove row. Liquid jet head.   The liquid ejecting head according to claim 6, wherein a plurality of the alignment marks are formed in proximity to the ejection grooves located at both ends of the groove row.   The liquid ejecting head according to claim 1, wherein the actuator substrate has alternately arranged the ejection grooves and the non-ejection grooves parallel to the ejection grooves.   The liquid ejecting head according to claim 1, wherein an alignment mark is formed on the nozzle plate at a position facing the alignment mark of the actuator substrate.   A liquid discharge chamber communicating with one end of the discharge groove and a liquid supply chamber communicating with the other end of the discharge groove are installed on the actuator substrate so as to partially cover the upper surface opening of the discharge groove. The liquid jet head according to claim 1, further comprising a cover plate. A liquid ejecting head according to claim 1;
A moving mechanism for relatively moving the liquid ejecting head and the recording medium;
A liquid supply pipe for supplying a liquid to the liquid ejecting head;
And a liquid tank that supplies the liquid to the liquid supply pipe. A groove forming step of forming a plurality of ejection grooves parallel to the piezoelectric substrate;
An alignment mark forming step for forming an alignment mark that is a lower surface of the piezoelectric substrate and is close to a substantially central position in a longitudinal direction of the lower surface opening in which the discharge groove opens;
And a nozzle plate installation step of installing a nozzle plate on the lower surface of the piezoelectric substrate. Forming an electrode on the piezoelectric substrate; and
A cover plate installation step of installing a cover plate on the upper surface of the piezoelectric substrate;
The method of manufacturing a liquid jet head according to claim 12, further comprising: grinding a lower surface of the piezoelectric substrate and penetrating the plurality of ejection grooves from the upper surface to the lower surface.   The method of manufacturing a liquid jet head according to claim 13, wherein the alignment mark forming step is a step performed after the piezoelectric substrate grinding step.   The method of manufacturing a liquid jet head according to claim 12, wherein the alignment mark forming step is a step of forming a groove that is parallel to a longitudinal direction of the plurality of discharge grooves and is shallower than the discharge grooves.

Images