JP7146521B2 - Inkjet head, inkjet device, and method for manufacturing inkjet head - Google Patents

Description

Embodiments of the present invention relate to an inkjet head, an inkjet device, and an inkjet head manufacturing method.

A share mode shared wall type ink jet head having a plurality of pressure chambers, in which a plurality of pressure chambers communicating with nozzles and a plurality of air chambers disposed between the pressure chambers are alternately provided in a predetermined parallel direction. configuration is known. Such a liquid ejection head is made by, for example, forming a plurality of grooves in the edges of a flat base substrate, and adhering cover plates made of thin ceramics or glass to cover air chambers on both sides of the base substrate. there is

JP-A-2000-168094

Since the cover plate has openings at positions corresponding to the plurality of pressure chambers, high processing accuracy is required. Further, high alignment accuracy is required when bonding the base substrate and the cover plate.

An object of the present invention is to provide an inkjet head, an inkjet device, and an inkjet head manufacturing method that are easy to manufacture.

An inkjet head according to one embodiment includes a base, a nozzle plate, and a cover plate. The base has a plurality of first grooves and a plurality of second grooves that are open on both sides at an edge in a second direction that extends in a first direction and intersects with the first direction. The nozzle plate has nozzles communicating with the first grooves. A cover plate is formed of a dry film resist, is arranged on both sides of the base in the second direction, closes the second groove, and has an opening communicating with the first groove.

1 is a perspective view of an inkjet head according to a first embodiment; FIG. FIG. 2 is a perspective view showing the internal structure of the inkjet head with a part broken away; Explanatory drawing which shows a part of the same inkjet head. Explanatory drawing which shows a part of the same inkjet head. Explanatory drawing which shows operation|movement of the same inkjet head. Explanatory drawing which shows operation|movement of the same inkjet head. Explanatory drawing which shows the manufacturing process of the same inkjet head. FIG. 2 is an explanatory diagram showing the configuration of an inkjet printer using the same inkjet head.

An inkjet head 1, which is a liquid ejection head, and an inkjet printer 100, which is an inkjet device, according to the first embodiment will be described below with reference to FIGS. 1 to 8. FIG. In each figure, for the sake of explanation, the configuration is shown enlarged, reduced, or omitted as appropriate. Arrows X, Y, and Z in the drawing indicate three directions orthogonal to each other. In this embodiment, the first direction of the inkjet head 1 is the X axis, the second direction is the Y axis, and the third direction is the Z axis.

FIG. 1 is a perspective view of an inkjet head 1 according to the first embodiment, and FIG. 2 is a perspective view showing the internal structure with a part of the inkjet head 1 cut away. FIG. 3 is an explanatory view showing the internal structure of the case member 40 of the inkjet head 1. As shown in FIG. FIG. 4 is an explanatory diagram showing the configuration of the base 10 of the inkjet head 1. As shown in FIG. 5 and 6 are explanatory diagrams showing the operation of the inkjet head 1. FIG.

The inkjet head 1 shown in FIGS. 1 to 6 is a so-called end shooter type shared mode shared wall inkjet head.

The inkjet head 1 includes a base 10 , a nozzle plate 20 having a plurality of nozzles 21 , a cover plate 30 as a cover member, and a case member 40 .

The base 10 includes a substrate 12 and a laminated piezoelectric body 13 as a piezoelectric portion.

The substrate 12 is configured in a rectangular plate shape. Substrate 12 is preferably constructed of PZT, ceramics, glass, machinable ceramics, or materials containing these.

The laminated piezoelectric body 13 is positioned at the edge of the substrate 12 on the nozzle plate 20 side. The laminated piezoelectric member 13 is configured by laminating two piezoelectric members. The piezoelectric member is made of, for example, a PZT (lead zirconate titanate) piezoelectric ceramic material. In addition, lead-free piezoelectric ceramics such as KNN (sodium potassium niobate) may be used as the piezoelectric member in consideration of the environment. The two piezoelectric members are polarized so that their polarization directions are opposite to each other, and are adhered via an adhesive layer.

A groove row 14A having a plurality of grooves 14 arranged in the first direction is formed on the end face of the laminated piezoelectric body 13 facing the nozzle plate 20 . A cross section along the XZ plane of the laminated piezoelectric body 13 has a comb shape. A pillar-like portion formed between adjacent grooves 14 constitutes a laminated piezoelectric element 15 that serves as a driving portion for changing the volume of the grooves 14 .

In the groove row 14A, a plurality of first grooves 14a and a plurality of second grooves 14b are alternately arranged in the first direction. The plurality of grooves 14 are arranged in parallel in the first direction, extend in the second direction, and are arranged parallel to each other. The grooves 14a and 14b are formed over the entire length of the base 10 in the second direction. That is, the grooves 14a and 14b are opened on the nozzle plate 20 side and the cover plate 30 side. Electrodes 16 are formed on the inner bottom and both side surfaces of the grooves 14a and 14b.

Both ends of the first groove 14a in the second direction are open inside the frame member 40a and communicate with the common chamber C3. A nozzle 21 is provided at a position facing the first groove 14a. That is, the first groove 14a constitutes a pressure chamber C1 communicating with the nozzle 21 as well as communicating with the common chamber C3.

Both ends of the second groove 14b in the second direction are covered with the cover plate 30 inside the frame member 40a. The second groove 14b is closed to form an air chamber C2 separated from the common chamber C3 and the pressure chamber C1.

The laminated piezoelectric element 15 is arranged between the plurality of grooves 14 on one end side of the base 10 . That is, the multiple laminated piezoelectric elements 15 are arranged in parallel in the first direction. Each laminated piezoelectric element 15 includes a first piezoelectric element 15a and a second piezoelectric element 15b laminated on the first piezoelectric element 15a.

The electrode 16 is a conductive film made of a conductive material such as nickel. The electrodes 16 are formed from the bottoms of the grooves 14 a and 14 b to the upper surface of the substrate 12 and connected to the wiring pattern 17 . The electrodes 16 are formed by, for example, a vacuum deposition method, an electroless nickel plating method, or the like. For example, if the electroless plating method is used, a metal film can be easily formed even in the fine grooves 14 . Although nickel is used as the material of the electrode 16 in this embodiment, the material is not limited to this.

The electrodes 16 may be made of gold, copper, or the like, for example. Alternatively, two or more conductive films may be laminated.

The wiring pattern 17 (wiring electrode) is a conductive film formed of a conductive material such as nickel similar to the electrode 16 and having a predetermined pattern shape. The wiring pattern 17 is formed on the pair of main surfaces 10 a and 10 b of the base 10 . The wiring pattern 17 is formed at the same time as the electrodes 16 are formed by, for example, a vacuum deposition method, an electroless plating method, or the like. A portion of the substrate 12 on the other side in the Z direction is exposed outside the frame member. Therefore, a drive circuit can be connected to the wiring pattern 17 arranged at this portion by FPC or the like.

The nozzle plate 20 is made of, for example, a polyimide film having a thickness of 10 μm to 100 μm and has a rectangular shape. A nozzle row having a plurality of nozzles 21 penetrating in the thickness direction is formed in the nozzle plate 20 . The nozzle plate 20 is arranged to face the opening of the groove row 14A on one end side of the base 10 in the second direction. The nozzles 21 are provided at positions corresponding to the plurality of pressure chambers C1. That is, the nozzle plate 20 has nozzles 21 communicating with the pressure chambers C1 formed by the first grooves 14a and closes the openings of the second grooves 14b.

The cover plate 30 is made of dry film resist. The cover plate 30 is made of, for example, an epoxy resin-based permanent film photoresist (permanent resist). The cover plate 30 has a film thickness of, for example, about 40 μm to 50 μm, and is provided on both end surfaces of the base 10 .

The cover plate 30 is a rectangular plate-like member having one edge on the nozzle plate side formed in a comb shape. A plurality of cutouts 31 that are openings are formed in the edge of the cover plate 30 . That is, the cover plate 30 has a plurality of notches 31 and a plurality of convex cover pieces 32 arranged between the notches 31 . It has a plurality of notches 31 and a plurality of cover pieces 32 . The plurality of notches 31 and the plurality of cover pieces 32 are arranged alternately. The notch 31 is formed through the cover plate 30 in the thickness direction. The notch 31 is arranged at a position corresponding to the first groove 14a. Therefore, both ends of the first groove 14a in the second direction are not covered with the cover plate 30 and open inside the frame member 40a. Therefore, the pressure chamber C1 formed by the first groove 14a communicates with the common chamber C3 formed outside the cover plate 30, and liquid such as ink flows into the pressure chamber C1 through the notch 31. As shown in FIG.

On the other hand, the cover piece 32 is arranged at a position corresponding to the second groove 14b. Therefore, the openings at both ends of the second groove 14b in the second direction are closed by the cover pieces 32 of the cover plate 30, thereby preventing the inflow of ink.

That is, on one end side of the base 10, the pressure chambers C1 communicating with the common chamber C3 and the closed air chambers C2 are alternately arranged.

The case member 40 integrally includes a frame member 40a having a rectangular frame shape and a plate-like lid member 40b that closes an opening of the frame member 40a. The frame member 40 a surrounds the outer periphery of the base 10 and covers the outer periphery of a part of the base 10 . Specifically, the frame member 40a has a pair of plate-like first frame pieces 41 joined to the end face of the base 10 in the first direction, and the main surfaces 10a and 10b, which are the outer surfaces of the base 10, separated by a predetermined distance. and a pair of plate-shaped second frame pieces 42 arranged in parallel. Between the frame member 40a and the base 10 covered with the cover plate 30, a common chamber C3 is formed. The common chamber C3 communicates with the pressure chamber C1 through the notch 31 of the cover plate 30. As shown in FIG. The frame member 40a functions as a guide for guiding liquid such as ink. An opening edge on one side of the frame member 40a is joined to the outer periphery of the nozzle plate 20, and a lid member 40b is provided on an opening edge on the other side of the frame member 40a.

The lid member 40b is constructed integrally with the frame member 40a. The lid member 40b is a rectangular plate-shaped member having a supply port through which ink flows into the common chamber C3 from the outside and a discharge port through which ink is discharged from the common chamber C3 to the outside. A supply channel 133a is connected to the supply port, and a recovery channel 133b is connected to the discharge port. The lid member 40b closes one side of the opening of the frame member 40a to form a common chamber C3.

That is, the nozzle plate 20, the frame member 40a, and the lid member 40b cover the actuator portion, which is the portion of the base 10 on the nozzle plate 20 side. Various electronic components such as a drive circuit are mounted on the wiring pattern 17 of the portion of the base 10 opposite to the nozzle plate 20 and extending outside the frame member 40a and the lid member 40b.

Inside the frame member 40a of the inkjet head 1 configured as described above, there are a plurality of pressure chambers C1 communicating with the nozzles 21, a plurality of air chambers C2 closed by the cover plate 30, and a plurality of pressure chambers. A common chamber C3 communicating with C1 is formed. The ink jet head 1 circulates ink in a channel passing through pressure chambers C1 and common chambers C3 formed therein.

A method for manufacturing the inkjet head 1 according to this embodiment will be described below with reference to FIGS.

First, as ST1, the base 10 without the groove 14 is formed. As a specific example, as shown in FIG. 7, two plate-shaped piezoelectric members polarized in the plate thickness direction are laminated so that the polarization directions alternate, and the laminated body is cut to a desired width and length. to form the laminated piezoelectric body 13 .

Furthermore, the laminated piezoelectric body 13 is attached to the plate-shaped substrate 12 made of a material different from that of the piezoelectric members constituting the laminated piezoelectric body 13 with an adhesive or the like, and the surface is polished or machined using a dicing saw, a slicer, or the like. to form a base 10 having a predetermined outer shape. For example, a block-shaped base member having a thickness corresponding to a plurality of sheets may be formed in advance and then divided to manufacture a plurality of bases 10 having a predetermined shape.

Subsequently, in ST2, the first groove 14a and the second groove 14b are formed in the laminated piezoelectric body 13 of the base 10 by machining. Furthermore, a conductive film such as an electrode 16 and a wiring pattern 17 is formed by a vacuum deposition method or the like on predetermined portions of the outer surface of the base 10 including the insides of the grooves 14a and 14b.

Subsequently, in ST3, plate-shaped dry film resists 30A that will serve as cover plates 30 are attached to both surfaces of the base 10. Then, as shown in FIG. Specifically, for example, a plate-shaped dry film resist 30A is pressed against both end surfaces of the base 10 in the second direction, and is thermally compressed by a heat roller at about 50.degree.

Subsequently, as ST4, an exposure process is performed. Specifically, first, for example, a photomask 50 having a negative pattern shape is superimposed on the end face of the base 10, and a pre-baking process is performed using the photomask at around 90° C., thereby removing the dry film resist 30A. Predetermined portions not covered with the photomask 50 are temporarily cured. Furthermore, by immersing the dry film resist 30A in a dedicated developer, a predetermined portion corresponding to the pattern shape of the photomask 50 is dissolved to form an opening that becomes the notch portion 31 . Furthermore, the dry film resist 30A is fully cured by performing a post-baking process at around 120°C. By the above exposure and development, the dry film resist 30A is formed into a predetermined shape in which a plurality of notches 31 and convex cover pieces 32 are alternately arranged as shown in FIG. For example, in the present embodiment, the notch 31 is arranged at a position facing the first groove 14a, and the cover piece 32 covers the second groove 14b.

Further, the frame member 40a is bonded and fixed to the outside of the cover plate 30 and polished, and the lid member 40b is attached by bonding so as to cover the common chamber C3 on the upper surface. Then, the nozzle plate 20 is adhered and attached so as to cover the grooves 14a and 14b. At this time, the nozzle plate 20 is attached at a position where the nozzles 21 are arranged to face the first grooves 14a and the second grooves 14b are closed. Furthermore, as shown in FIG. 1, the inkjet head 1 is completed by connecting the driving IC chip 52 and the circuit board 53 to the wiring pattern 17 formed on the main surface of the substrate 12 via the flexible cable 51 .

Next, an inkjet printer 100 having the inkjet head 1 will be described with reference to FIG. FIG. 8 is an explanatory diagram showing the configuration of the inkjet printer 100. As shown in FIG. As shown in FIG. 8, the inkjet printer 100 includes a housing 111, a medium supply section 112, an image forming section 113, a medium discharge section 114, a conveying device 115, and a control section .

The inkjet printer 100 conveys a recording medium, such as paper P, which is an object to be ejected, along a predetermined conveyance path A1 from a medium supply unit 112 through an image formation unit 113 to a medium discharge unit 114, while feeding ink or the like. It is a liquid ejection device that performs an image forming process on a sheet of paper P by ejecting liquid.

The medium supply unit 112 includes a plurality of paper feed cassettes 112a. The medium ejection unit 114 includes a paper ejection tray 114a. The image forming section 113 includes a support section 117 that supports a sheet, and a plurality of head units 130 arranged above the support section 117 so as to face each other.

The support portion 117 includes a conveying belt 118 provided in a loop shape in a predetermined area for image formation, a support plate 119 supporting the conveying belt 118 from the back side, and a plurality of belt rollers 120 provided on the back side of the conveying belt 118 . , provided.

The head unit 130 includes a plurality of inkjet heads 1, a plurality of ink tanks 132 as liquid tanks mounted on each inkjet head 1, a connection flow path 133 connecting the inkjet heads 1 and the ink tanks 132, and a circulation pump 134 that is a circulation unit. The head unit 130 is a circulation type head unit that circulates liquid.

In the present embodiment, the ink jet heads 1C, 1M, 1Y, and 1B of four colors of cyan, magenta, yellow, and black are used as the ink jet heads 1, and ink tanks 132C and 132M are used as the ink tanks 132 that respectively contain the inks of these colors. , 132Y, 132B. The ink tank 132 is connected to the inkjet head 1 by a connection channel 133 . The connection channel 133 includes a supply channel 133 a connected to the supply port of the inkjet head 1 and a recovery channel 133 b connected to the discharge port of the inkjet head 1 .

The ink tank 132 is also connected to a negative pressure control device such as a pump (not shown). The negative pressure in the ink tank 132 is controlled by the negative pressure control device corresponding to the head pressure of the ink jet head 1 and the ink tank 132, so that the ink supplied to each nozzle of the ink jet head 1 is formed into a predetermined shape. A meniscus is formed.

The circulation pump 134 is, for example, a liquid feed pump configured by a piezoelectric pump. The circulation pump 134 is provided in the supply channel 133a. The circulation pump 134 is connected to the drive circuit of the controller 116 by wiring. A CPU (Central Processing Unit) 116 a is configured to be able to control a circulation pump 134 . A circulation pump 134 circulates the liquid in a circulation channel including the inkjet head 1 and the ink tank 132 .

The transport device 115 transports the paper P along the transport path A1 from the paper feed cassette 112 a of the medium supply unit 112 to the paper discharge tray 114 a of the medium discharge unit 114 through the image forming unit 113 . The conveying device 115 includes a plurality of guide plate pairs 121a to 121h arranged along the conveying path A1 and a plurality of conveying rollers 122a to 122h.

The control unit 116 includes a CPU 116a as a controller, a ROM (Read Only Memory) for storing various programs, a RAM (Random Access Memory) for temporarily storing various variable data, image data, and the like. and an interface unit for inputting data from and outputting data to the outside.

When the inkjet head 1 and the inkjet printer 100 are driven to eject liquid from the nozzles 21 , the control unit 116 applies a driving voltage via the wiring pattern 17 by the driving circuit. When a potential difference is applied between the electrodes in the pressure chamber C1 driven by voltage application and the electrodes in the air chambers C2 on both sides, the first piezoelectric element 15a and the second piezoelectric element 15b are deformed in the opposite directions to each other. The deformation of the element bends and deforms the driving element. For example, as shown in FIG. 5, first, the pressure chamber C1 to be driven is deformed in the opening direction to create a negative pressure in the pressure chamber C1, thereby introducing the ink into the pressure chamber C1 through the notch 31. As shown in FIG. Subsequently, as shown in FIG. 6, the pressure chamber C1 is deformed in a closing direction to pressurize the inside of the pressure chamber C1, thereby ejecting an ink droplet from the nozzle 21. As shown in FIG.

According to the inkjet head 1 and the inkjet printer 100 according to the present embodiment, the cover plate 30 that closes the air chamber C2 and opens the pressure chamber C1 is formed of dry film resist. Therefore, it is possible to precisely form the pressure chambers C1 and the air chambers C2 that are densely arranged. For example, if the base 10 is made of a ceramic material and a cover plate made of a resin material is bonded by thermocompression bonding, the difference in thermal expansion coefficient between the base and the cover plate may cause a positional difference during heat treatment during bonding. Due to the misalignment, it is difficult to manufacture with high accuracy. On the other hand, when using an adhesive that can bond at low temperatures, it becomes difficult to ensure chemical resistance due to restrictions on the material, so the inks that can be used are limited. It is also conceivable to form the cover plate from a ceramic material in the same manner as the base. On the other hand, according to the present embodiment, since the cover plate 30 is made of dry film resist, high-definition molding can be easily performed using exposure processing. It is easier to manufacture than the case of machining the , and the manufacturing cost can be kept low. Furthermore, compared with the case where the cover plate 30 made of a resin material is adhered by thermocompression, displacement due to thermal deformation is less likely to occur.

It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the present invention at the implementation stage.

In the above embodiment, the so-called end shooter type inkjet head 1 is exemplified, but the present invention is not limited to this. For example, it may be applied to a side shooter type inkjet head. In the above embodiment, the base 10 has the grooves 14a and 14b extending to both ends in the second direction, and the cover plates 30 are provided on both sides, but the present invention is not limited to this. For example, the base 10 may have a first groove 14a and a second groove 14b that open on one side, and the cover plate 30 may be arranged only on one side of the base 10. FIG. Also in this case, the same effect as the above embodiment can be obtained.

Further, in the above-described embodiment, the base 10 having the laminated piezoelectric member 13 made of a piezoelectric member on the substrate 12 is illustrated, but the present invention is not limited to this. For example, the base 10 may be formed only by a piezoelectric member without using the substrate 12 . Also, instead of using two piezoelectric members, one piezoelectric member may be used.

According to at least one embodiment described above, it is possible to provide an inkjet head and an inkjet device that are easy to manufacture.

Additionally, while several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.
Description equivalent to the invention described in the scope of claims at the time of filing of the present application will be added below.
[1] a base having a plurality of first grooves and a plurality of second grooves opening in at least one of a first direction and a second direction crossing the first direction;
a nozzle plate having nozzles communicating with the first groove;
a cover plate formed of a dry film resist, disposed on at least one side of the base in the second direction, closing the second groove, and having an opening communicating with the first groove;
an inkjet head.
[2] The inkjet head according to [1], wherein the cover plate is made of a permanent resist.
[3] A frame member having a frame piece arranged opposite to the outer surface of the base and forming a common chamber between itself and the base,
the first groove constitutes a pressure chamber that communicates with the nozzle and the common chamber;
said second groove defines an air chamber adjacent to said pressure chamber and separated from said common chamber by said cover plate;
The inkjet head according to [1] or [2].
[4] The inkjet head according to any one of [1] to [3];
and a transport device that transports a medium along a predetermined transport path.
[5] At least one side in the second direction of a base having a plurality of first grooves and a plurality of second grooves opening in at least one of a second direction that extends in a first direction and intersects with the first direction. affix dry film resist to
A method for manufacturing an inkjet head, wherein the dry film resist is formed into a shape in which a portion facing the first groove is opened by exposure processing.

DESCRIPTION OF SYMBOLS 1... Inkjet head 10... Base 12... Substrate 13... Laminated piezoelectric body 14... Groove 14A... Groove row 14a... First groove 14b... Second groove 15... Laminated piezoelectric element 15a... Piezoelectric element 15b Piezoelectric element 16 Electrode 17 Wiring pattern 20 Nozzle plate 21 Nozzle 30 Cover plate 30A Dry film resist 31 Notch 32 Cover piece 40 Case Members 40a Frame member 40b Lid member 41 Frame piece 42 Frame piece 50 Photomask 51 Flexible cable 52 Drive IC chip 53 Circuit board 100 Inkjet printer 111 Housing 112 Medium supply unit 112a Paper feed cassette 113 Image forming unit 114 Medium discharge unit 114a Paper discharge tray 115 Conveyor 116 Control unit 116a CPU 133 Connection Flow path 133a Supply flow path 133b Recovery flow path 134 Circulation pump A1 Transfer path C1 Pressure chamber C2 Air chamber C3 Common chamber.

Claims (5)

a base having a plurality of first grooves and a plurality of second grooves opening on both sides at an edge in a second direction that extends in a first direction and intersects with the first direction;
a nozzle plate having nozzles communicating with the first groove;
a cover plate formed of a dry film resist, disposed on both sides of the base in the second direction, closing the second groove, and having an opening communicating with the first groove;
an inkjet head. 2. The inkjet head of claim 1, wherein the cover plate is made of permanent resist. A frame member having a frame piece arranged opposite to the outer surface of the base and forming a common chamber between itself and the base,
the first groove constitutes a pressure chamber that communicates with the nozzle and the common chamber;
said second groove defines an air chamber adjacent to said pressure chamber and separated from said common chamber by said cover plate;
The inkjet head according to claim 1 or 2. The inkjet head according to any one of claims 1 to 3;
and a transport device that transports a medium along a predetermined transport path. on both sides in the second direction of a base having a plurality of first grooves and a plurality of second grooves opening on both sides at edges in a first direction and in a second direction intersecting the first direction; , apply dry film resist,
A method of manufacturing an inkjet head, wherein the dry film resist is formed into a shape in which a portion facing the first groove is opened by exposure processing.

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