Liquid ejection head, liquid ejection unit, liquid ejection device, and method for manufacturing liquid ejection head

Abstract

To obtain a high liquid discharge performance in such a manner that a damper member properly functions even in a liquid discharge head having a fine structure.SOLUTION: A liquid discharge head, which discharges liquid in each pressure chamber supplied from a liquid channel from each nozzle by driving an electromechanical conversion element on an actuator substrate, comprises a damper member 60 which absorbs pressure fluctuation in the liquid channel by a damper membrane 66 deposited on a damper frame substrate 65. The damper member properly functions, and thus, the liquid discharge head obtains high liquid discharge accuracy.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, a device for ejecting liquid, and a method for manufacturing a liquid ejection head. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a liquid ejection head that ejects liquid from a nozzle by driving an electromechanical conversion element on an actuator substrate, the liquid being supplied from a liquid flow path within a pressure chamber.

[0003] For example, Patent Document 1 discloses an inkjet recording head (liquid ejection head) in which a damper plate (damper member) that absorbs pressure fluctuations in an ink storage chamber (liquid flow path) is made of ceramic to improve its ink resistance. In this recording head, the damper plate, made of a ceramic material (green sheet) on which a desired pattern has been formed using a punching method, is laid on a damper chamber forming plate (damper frame substrate) also made of a ceramic material (green sheet), and then fired to bond the damper plate to the damper chamber forming plate. Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional liquid ejection heads have a problem in that the damper member cannot fully function due to its fine structure, and crosstalk reduces the accuracy of liquid ejection. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head that ejects liquid from each nozzle by driving an electromechanical conversion element on an actuator substrate, the liquid being supplied from each pressure chamber through a liquid flow path, the liquid ejection head including a damper film formed on a damper frame substrate. and displacing the damper film within a displacement space formed between the damper frame substrate and the damper film. By 、 The device is characterized by including a damper member that absorbs pressure fluctuations within the liquid flow path. [Effects of the Invention]

[0006] According to the present invention, even in a liquid ejection head having a fine structure, the damper member can fully demonstrate its function, and therefore it is possible to suppress a decrease in liquid ejection accuracy due to crosstalk. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory perspective view of the appearance of a liquid ejection head according to an embodiment. [Figure 2] FIG. [Figure 3] FIG. 2 is a cross-sectional perspective view illustrating the liquid ejection head. [Figure 4] FIG. 2 is an exploded perspective view of the liquid ejection head excluding a frame member. [Figure 5] FIG. 2 is a cross-sectional perspective view illustrating a flow path portion of the liquid ejection head. [Figure 6] FIG. 2 is an enlarged perspective cross-sectional view of a flow path portion of the liquid ejection head. [Figure 7] FIG. 2 is a plan view illustrating a flow path portion of the liquid ejection head. [Figure 8] FIG. 3 is a perspective view showing a damper member of the liquid ejection head. [Figure 9] FIG. 9 is an enlarged plan view of the dashed line portion shown in FIG. 8. [Figure 10] 10 is a cross-sectional view of a portion indicated by the symbol A in FIG. 9. [Figure 11] 10 is a cross-sectional view of the portion indicated by the symbol B in FIG. 9. [Figure 12] 10(a) to 10(e) are cross-sectional views of the portion indicated by the symbol A in FIG. 9 in each manufacturing process of the damper member. [Figure 13] 10(a) to 10(e) are cross-sectional views of the portion indicated by the symbol B in FIG. 9 in each manufacturing process of the damper member. [Figure 14] 10 is a cross-sectional view of a portion of the damper member of the first modified example, the portion corresponding to the portion indicated by the symbol A in FIG. 9. [Figure 15] 10 is a cross-sectional view of a portion of the damper member of Modification 2 corresponding to the portion indicated by the symbol A in FIG. 9. [Figure 16] FIG. 2 is an exploded perspective view illustrating a head module according to the embodiment. [Figure 17] FIG. 2 is an exploded perspective view illustrating the head module according to the embodiment, as viewed from the nozzle surface side. [Figure 18] FIG. 1 is a schematic diagram illustrating a printing apparatus according to an embodiment. [Figure 19] FIG. 2 is an explanatory plan view of an example of a head unit of a printing device. [Figure 20] FIG. 1 is an explanatory plan view of a main part of an example of a printing apparatus. [Figure 21] FIG. 1 is an explanatory side view of a main part of an example of a printing device. [Figure 22] FIG. 2 is a plan view illustrating a main part of an example of a liquid ejection unit. [Figure 23] FIG. 2 is a front view illustrating an example of a liquid ejection unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment in which the present invention is applied to a liquid ejection head provided in an apparatus for ejecting liquid will be described below. FIG. 1 is an explanatory perspective view of the appearance of a liquid ejection head according to this embodiment. FIG. 2 is an exploded perspective view of the liquid ejection head. FIG. 3 is a cross-sectional perspective view of the liquid ejection head. FIG. 4 is an exploded perspective view of the liquid ejection head excluding the frame member. FIG. 5 is a cross-sectional perspective view of a flow path portion of the liquid ejection head. FIG. 6 is an enlarged perspective cross-sectional view of a flow path portion of the liquid ejection head. FIG. 7 is an explanatory plan view of the flow path portion of the liquid ejection head.

[0009] The liquid ejection head 1 of this embodiment includes a nozzle plate 10, a flow path plate (individual flow path member) 20, a diaphragm member 30, a common flow path member 50, a damper member 60, a frame member 80, and a substrate (flexible wiring substrate) 101 on which a drive circuit 102 is mounted. The nozzle substrate that constitutes the nozzle plate 10, the actuator substrate that constitutes the individual flow path member 20 and the diaphragm member 30, the subframe substrate that constitutes the common flow path member 50, and the damper substrate that constitutes the damper member 60 are all made from single-crystal Si wafers as substrate materials, and multiple chips (liquid ejection heads) are simultaneously fabricated on the Si wafers using microfabrication technology for MEMS and semiconductor devices, and the substrates after being made into chips are bonded together to form the liquid ejection head.

[0010] A plurality of nozzles 11 that eject liquid are provided on the nozzle plate 10. The plurality of nozzles 11 are arranged in a two-dimensional matrix, and are aligned in three directions, a first direction F, a second direction S, and a third direction T, as shown in FIG.

[0011] The individual flow path member 20 forms a plurality of pressure chambers (individual liquid chambers) 21 each communicating with a plurality of nozzles 11, a plurality of individual supply flow paths 22 each communicating with the plurality of pressure chambers 21, and a plurality of individual recovery flow paths 23 each communicating with the plurality of pressure chambers 21. One pressure chamber 21 and the individual supply flow path 22 and individual recovery flow path 23 communicating therewith are collectively referred to as an individual flow path 25.

[0012] The vibration plate member 30 forms a vibration plate 31 which is a deformable wall surface of the pressure chamber 21, and a piezoelectric element 40 is integrally provided on the vibration plate 31. The vibration plate member 30 also has a supply-side opening 32 which communicates with the individual supply flow path 22 and a recovery-side opening 33 which communicates with the individual recovery flow path 23. The piezoelectric element 40 is an electromechanical conversion element, and is pressure generating means which deforms the vibration plate 31 to pressurize the liquid in the pressure chamber 21.

[0013] The individual flow path member 20 and the diaphragm member 30 are not limited to being separate members. For example, the individual flow path member 20 and the diaphragm member 30 can be integrally formed from the same member using an SOI (Silicon On Insulator) substrate. That is, an SOI substrate having a silicon oxide film, a silicon layer, and a silicon oxide film formed in this order on a silicon substrate can be used, with the silicon substrate serving as the individual flow path member 20 and the diaphragm 31 being formed from the silicon oxide film, the silicon layer, and the silicon oxide film. In this configuration, the layer structure of the silicon oxide film, the silicon layer, and the silicon oxide film of the SOI substrate becomes the diaphragm member 30. In this way, the diaphragm member 30 includes one made of a material formed on the surface of the individual flow path member 20.

[0014] The common flow path member 50 forms a plurality of common supply flow path tributaries 52 that lead to two or more individual supply flow paths 22 and a plurality of common recovery flow path tributaries 53 that lead to two or more individual recovery flow paths 23, which are alternately adjacent to each other in the second direction S of the nozzle 11.

[0015] The common flow path member 50 has a through hole which serves as a supply port 54 connecting the supply side opening 32 of the individual supply flow path 22 and the common supply flow path tributary 52, and a through hole which serves as a recovery port 55 connecting the recovery side opening 33 of the individual recovery flow path 23 and the common recovery flow path tributary 53.

[0016] In addition, the common flow path member 50 forms one or more common supply flow path main streams 56 that communicate with multiple common supply flow path tributaries 52, and one or more common recovery flow path main streams 57 that communicate with multiple common recovery flow path tributaries 53.

[0017] The damper member 60 has a supply side damper 62 facing (opposing) the supply port 54 of the common supply flow path branch 52, and a recovery side damper 63 facing (opposing) the recovery port 55 of the common recovery flow path branch 53.

[0018] Here, the common supply flow path branch 52 and the common recovery flow path branch 53 are formed by sealing grooves arranged alternately in the common flow path member 50, which is the same member, with supply-side dampers 62 or recovery-side dampers 63 of the damper member 60. Note that the damper material of the damper member 60 is preferably a metal thin film or an inorganic thin film that is resistant to organic solvents. The thickness of the supply-side dampers 62 and recovery-side dampers 63 of the damper member 60 is preferably 10 μm or less.

[0019] The liquid ejection head 1 of this embodiment is provided with a damper member 60 that suppresses the influence (e.g., crosstalk) that pressure fluctuations in a liquid flow path (e.g., individual supply flow path 22) that occur when liquid is ejected from a nozzle 11 have on the liquid ejection from other nozzles 11. By allowing the damper member 60 to properly perform its damping function, it is possible to suppress crosstalk, in which vibrations (pressure fluctuations) during liquid ejection are propagated through the liquid and affect the liquid ejection of adjacent nozzles, and it is possible to stabilize the liquid ejection accuracy of each nozzle 11.

[0020] A typical damper member is constructed by overlapping a damper plate on a damper frame substrate, which has a displacement space (gap) formed to allow the damper plate to displace, and then bonding the two together with an adhesive. However, bonding methods that use adhesive inevitably result in variations in the alignment accuracy between the damper plate and the damper frame substrate, as well as variations in the amount of adhesive that spills into the displacement space, which leads to large variations in damper function and variations in liquid ejection accuracy.

[0021] On the other hand, conventional liquid ejection heads, which bond a ceramic damper plate and damper frame substrate together by sintering, do not use adhesive, so there is no variation in the amount of adhesive that spills into the displacement space (gap). However, because the damper plate, which is a separate component, must be superimposed on the damper frame substrate, it is difficult to make the damper plate thin. This makes it difficult to achieve the damping function required for liquid ejection heads, which have become increasingly miniaturized in recent years, and to achieve high liquid ejection accuracy from each nozzle.

[0022] Therefore, the damper member 60 in this embodiment is configured by depositing a damper film on a damper frame substrate. In this configuration, by using film deposition techniques in semiconductor manufacturing processes, it is possible to deposit a thin damper film on the damper frame substrate with high precision. Therefore, the liquid ejection head 1 of this embodiment can be equipped with a damper member 60 that can achieve the damping function required for liquid ejection heads that are becoming increasingly miniaturized. Therefore, according to this embodiment, in a liquid ejection head 1 with a fine structure, the damper member 60 can appropriately perform the damping function, and liquid ejection precision can be stabilized.

[0023] FIG. 8 is a perspective view showing the damper member 60 in this embodiment. FIG. 9 is an enlarged plan view of the dashed line portion shown in FIG. FIG. 10 is a cross-sectional view of a portion indicated by the symbol A in FIG. FIG. 11 is a cross-sectional view of the portion indicated by the symbol B in FIG.

[0024] In practice, a plurality of damper members 60 corresponding to a plurality of chips (liquid ejection heads 1) are fabricated on a Si wafer, but here, one damper member 60 corresponding to one liquid ejection head 1 will be described.

[0025] As shown in Figure 8, the damper member 60 is a rectangular plate-shaped member, and along its long sides, through holes 61A and 61B are formed in the damper member 60, which communicate with the common supply flow path main stream 56 and the common recovery flow path main stream 57 of the common flow path member 50, and a supply side damper 62 and a recovery side damper 63, which are damper membranes, are formed in the area sandwiched between these through holes 61A and 61B.

[0026] 8 and 9, the supply-side damper 62 and the recovery-side damper 63 of the damper member 60 are each composed of a recess (gap) 64 formed in a damper frame substrate 65 and a damper membrane 66 covering the recess. The recess (gap) 64 is a displacement space that allows the damper membrane 66 to be displaced. The gaps 64 of the supply-side damper 62 and the recovery-side damper 63 are separated from each other by a gap partition wall.

[0027] The damper member 60 is formed by depositing a portion of the damper film 66 out of the multiple layers (damper film) on a damper frame substrate 65, and then forming a gap-forming hole 64b, which is a space-forming hole, in the portion of the damper film. Then, using a sacrificial layer removal method, a portion of the damper frame substrate 65 surrounded by the portion of the damper film and the gap partition wall 67 is removed through the gap-forming hole 64b, and the removed space becomes the gap 64. After the gap 64 is formed, the remaining damper film is deposited to seal the gap-forming hole 64b.

[0028] Since the remaining sealing (film formation) with the damper-constituting film is performed in a vacuum, it is necessary to later open the void 64 to the atmosphere. Therefore, when the void 64 is formed, an atmosphere-communicating part 68 that communicates with the void 64 is formed, so that when the wafer is diced into chips, the atmosphere-communicating part 68 is exposed at the end of the chip, and the void 64 is opened to the atmosphere.

[0029] Next, an example of a manufacturing process for the damper member 60 of this embodiment will be described. 12(a) to 12(e) are cross-sectional views of the portion indicated by the symbol A in FIG. 9 in each manufacturing process of the damper member 60. 13(a) to 13(e) are cross-sectional views of the portion indicated by the symbol B in FIG. 9 in each manufacturing process of the damper member 60. FIG. 12(a) and 13(a) is prepared as the damper frame substrate 65 constituting the damper member 60. This SOI wafer is, for example, formed by forming a thermally oxidized film having a thickness of 0.3 μm as a BOX layer 65a on a silicon single crystal substrate (for example, a thickness of 400 μm) 65 having a (110) plane orientation, and then forming an active layer 65b having a thickness of 10 μm as a silicon single crystal film thereon.

[0030] 12(a) and 13(a), a barrier layer filling groove 65c is formed in the active layer 65b as a partition wall forming hole to be filled with a barrier layer for etching in a subsequent gap forming step using a sacrificial layer removal method. This barrier layer filling groove 65c can be formed by, for example, a general litho-etching method.

[0031] After the barrier layer filling groove 65c is formed in the active layer 65b on the damper frame substrate 65, a silicon oxide film 66a, which is the first layer of the damper-constituting films that will become the barrier layer, is formed by thermal oxidation, as shown in Figures 12(b) and 13(b). This silicon oxide film 66a becomes the barrier layer by filling the barrier layer filling groove 65c.

[0032] To fill the barrier layer filling groove 65c with the silicon oxide film 66a, which is the first layer of the damper-constituting film, it is necessary to satisfy the condition shown in the following formula (1), for example. In formula (1), "W" is the groove width of the barrier layer filling groove 65c, and "T" is the film thickness of the silicon oxide film 66a. For example, if the film thickness T of the silicon oxide film 66a is 0.9 μm, the barrier layer filling groove 65c needs a groove width W of approximately 1 μm. W ≧ 0.56×2T (1)

[0033] As will be described later, the silicon oxide film 66a filled in the barrier layer filling groove 65c becomes a gap partition 64a that partitions the gap 64. If it is necessary to ensure the strength of the gap partition 64a, a configuration may be adopted in which a plurality of barrier layer filling grooves 65c are formed in parallel, and the gap 64 is partitioned by the plurality of parallel gap partitions 64a.

[0034] Here, compressive stress acts on the formed silicon oxide film 66a, and if the void 64 is formed in this state, there is a risk that the silicon oxide film 66a will buckle. Therefore, in this embodiment, in order to suppress buckling of the silicon oxide film 66a, a film on which tensile stress acts, such as a silicon nitride film 66b, is formed on the silicon oxide film 66a. This makes it possible to achieve a balance of stress in the damper film 66 covering the void 64, and suppress the occurrence of buckling or wrinkles.

[0035] In this case, the overall stress of the damper film 66 is preferably 50 MPa or less if it is a compressive stress, or 150 MPa or less if it is a tensile stress. Within these ranges, the necessary damping function can be ensured and damage to the damper film 66 due to stress can be suppressed.

[0036] Furthermore, it is preferable to form the damper film 66 from an inorganic material. By using an inorganic material, there are no restrictions on the thermal history of the construction method, as there are when using a resin material, and there is a high degree of freedom in the construction method that can be selected.

[0037] 12(c) and 13(c), in order to form the void 64, void-forming holes 64b are formed in the silicon oxide film 66a and the silicon nitride film 66b by a general litho-etching method. Thereafter, by a method capable of etching the active layer 65b, which is a silicon single crystal film, for example, a sacrificial layer removal method using SF6 gas, the active layer 65b in the portion that will become the void 64 is removed through the void-forming holes 64b, thereby forming the void 64 as a displacement space.

[0038] 12(d) and 13(d), in order to seal the gap-forming holes 64b, for example, a silicon oxide film 66c is formed by CVD or the like as the remaining damper-constituting film of the three layers that make up the damper film 66. In this way, the damper film 66 is formed as a three-layer laminated film.

[0039] As described above, the damper film 66 of this embodiment employs a layered structure to fulfill multiple roles: ensuring film rigidity as a damper, preventing buckling, forming the gap partition wall 64a by filling the barrier layer filling groove 65c, and sealing the gap-forming hole 64b. In this embodiment, the damper film 66 has a three-layer structure consisting of a silicon oxide film (silicon thermal oxide film) 66a, a silicon nitride film 66b, and a silicon oxide film 66c, but this is not limiting. The damper film 66 may be made of a different material as long as it can fulfill at least one of the multiple roles described above, and the number of layers may be two or less or four or more.

[0040] 12(e) and 13(e), through-holes 61A and 61B for supplying liquid are formed by a general litho-etching method. After that, a liquid-resistant film 69, for example, a TaSiO film with a thickness of about 50 nm, is formed by an ALD method or the like in the portions that will come into contact with the liquid.

[0041] Finally, stealth dicing is performed to divide the damper member 60 into chips. Before being divided into chips, the voids 64 are formed in a vacuum and sealed, so they are under negative pressure relative to atmospheric pressure, and the damper films 66 (66a, 66b, 66c) covering the voids 64 are bent toward the voids 64. However, this bending is eliminated because the voids 64 are opened to the atmosphere via the atmosphere communication parts 68 at the same time as being divided into chips.

[0042] As described above, in this embodiment, since the production of the damper member 60 does not involve a bonding process using an adhesive, there is no variation in damping function due to variations in the amount of adhesive spilling into the gap 64, and variation in liquid ejection accuracy is suppressed. Furthermore, as described above, the damper member 60 of this embodiment is produced using microfabrication technology in semiconductor manufacturing processes and the like, and is therefore compatible with liquid ejection heads 1 that will continue to become increasingly dense and accurate. Therefore, it is possible to provide a damper member 60 that is highly accurate and reliable, and to realize a liquid ejection head 1 that is highly accurate and reliable.

[0043] In addition, unlike conventional damper members, which are made by joining separate components, namely a damper plate and a damper frame substrate, the damper member 60 consisting of a damper film 66 and a damper frame substrate 65, is integrally formed on a Si wafer, which also reduces manufacturing costs and improves yields.

[0044] [Variation 1] Next, a modified example of the damper member 60 of the liquid ejection head 1 in this embodiment (hereinafter, this modified example will be referred to as "Modified Example 1") will be described. FIG. 14 is a cross-sectional view of the damper member 60 of the first modified example, taken at a location corresponding to the location indicated by the symbol A in FIG.

[0045] The present modified example 1 reduces material costs compared to the damper member 60 of the above-described embodiment. Specifically, the damper member 60 of the above-described embodiment is fabricated using a damper frame substrate 65 made of an SOI wafer, but the present modified example 1 is fabricated using a damper frame substrate 65 made of a silicon wafer, the wafer cost of which is significantly cheaper than that of an SOI wafer (for example, about 1 / 10).

[0046] In the above-described embodiment, during etching (sacrificial layer removal method) to form the void 64, the depth of the void 64 to be removed is determined by the thickness of the active layer 65b of the SOI wafer. That is, even if the active layer 65b is etched and the BOX layer 65a is exposed, the etching selectivity (etching rate) is so large that the etching stops at the BOX layer 65a, and as a result, the depth of the void 64 is substantially determined only by the thickness of the active layer 65b.

[0047] In contrast to this, in the present modified example 1, the void 64 is formed by removing the surface portion (silicon portion) of the silicon wafer by etching (sacrificial layer removal method). Therefore, there is no barrier layer (etching stop layer) that stops etching like the BOX layer 65a in the above-described embodiment, and therefore the depth of the removed void 64 varies more than in the above-described embodiment, as shown in Fig. 14. In particular, care must be taken to ensure that the depth of the void 64 does not exceed the height of the void partition 64a.

[0048] In this first modification, by appropriately selecting the etching conditions, it is possible to control the depth tolerance of the void 64 within the design variation range so that the desired damping function can be obtained for the depth of the void 64. Therefore, according to this first modification, it is possible to obtain a damper member 60 that exhibits sufficient damping function while suppressing material costs and reducing manufacturing costs.

[0049] [Variation 2] Next, another modified example of the damper member 60 of the liquid ejection head 1 in this embodiment (hereinafter, this modified example will be referred to as "Modified Example 2") will be described. FIG. 15 is a cross-sectional view of the damper member 60 of the second modified example, taken at a location corresponding to the location indicated by the symbol A in FIG.

[0050] Similar to the above-described first modification, in the present second modification, the damper member 60 is manufactured using a damper frame substrate 65 made of a silicon wafer in order to reduce material costs compared to the damper member 60 of the above-described embodiment. However, in the present second modification, for example, a silicon oxide film 65d is formed on the silicon wafer as a layer that will become the sacrificial layer and the gap partition 67. Then, after forming a barrier layer filling groove 65c in this silicon oxide film 65d, a first layer of the damper-constituting films that will become the barrier layer is formed.

[0051] At this time, as the first layer of the damper-constituting films, for example, a polysilicon film 66a' having a high selectivity to the silicon oxide film 65d serving as the sacrificial layer is formed. The subsequent steps are the same as those in the above-described embodiment, but the sacrificial layer removal method uses HF vapor treatment to remove the silicon oxide film 65d.

[0052] In the second modification, too, it is possible to obtain a damper member 60 that exhibits sufficient damping function while suppressing material costs and reducing manufacturing costs.

[0053] Next, an example of a head module including the liquid ejection head 1 of this embodiment will be described with reference to FIGS. FIG. 16 is an exploded perspective view illustrating the head module of this embodiment. FIG. 17 is an exploded perspective explanatory view of the head module of this embodiment as seen from the nozzle surface side.

[0054] The head module 100 includes a liquid ejection head (hereinafter simply referred to as a "head") 1 that ejects liquid, a base member 103 that holds the multiple heads 1, and a cover member 113 that serves as nozzle covers 15 for the multiple heads 1. The head module 100 also includes a heat dissipation member 104, a manifold 105 that forms a flow path that supplies liquid to the multiple heads 1, a printed circuit board (PCB) 106 that connects to the flexible wiring member 101, and a module case 107.

[0055] Next, an example of a liquid ejection device according to the present invention will be described with reference to FIGS. FIG. 18 is a schematic explanatory diagram of a printing apparatus, which is an inkjet recording apparatus serving as a device for ejecting liquid in this embodiment. FIG. 19 is an explanatory plan view of an example of a head unit of a printing apparatus according to this embodiment.

[0056] The printing device 500, which is a device for ejecting this liquid, includes an input means 501 for inputting a continuous body 510, a guide and conveyance means 503 for guiding and conveying the continuous body 510 inputted from the input means 501 to a printing means 505, a printing means 505 for ejecting a liquid onto the continuous body 510 to perform printing to form an image, a drying means 507 for drying the continuous body 510, and an output means 509 for outputting the continuous body 510.

[0057] The continuous web 510 is sent out from a main winding roller 511 of the carry-in means 501, guided and conveyed by the rollers of the carry-in means 501, the guide and conveying means 503, the drying means 507, and the conveying means 509, and wound up by a winding roller 591 of the conveying means 509. In the printing means 505, the continuous web 510 is conveyed on a conveying guide member 559 opposite the head unit 550, and an image is printed by liquid ejected from the head unit 550.

[0058] In the printing device 500 of this embodiment, the head unit 550 includes the two head modules 100A and 100B according to this embodiment described above, mounted on a common base member 552.

[0059] When the direction in which the heads 1 are lined up in the direction perpendicular to the transport direction of the head modules 100A and 100B is defined as the head arrangement direction, the head arrays 1A1 and 1A2 of the head module 100A eject liquid of the same color. Similarly, the head arrays 1B1 and 1B2 of the head module 100A are paired, the head arrays 1C1 and 1C2 of the head module 100B are paired, and the head arrays 1D1 and 1D2 are paired, and each ejects liquid of the required color.

[0060] Next, another example of a printing apparatus as a liquid ejecting apparatus according to the present invention will be described with reference to FIGS. 20 and 21. FIG. FIG. 20 is an explanatory plan view of the main parts of the printing apparatus of this example. FIG. 21 is an explanatory side view of the main part of the printing apparatus of this example.

[0061] The printing apparatus 500 of this example is a serial type apparatus, and a carriage 403 is moved back and forth in the main scanning direction by a main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, etc. The guide member 401 is hung between left and right side plates 491A and 491B to movably hold the carriage 403. The main scanning motor 405 then moves the carriage 403 back and forth in the main scanning direction via a timing belt 408 hung between a drive pulley 406 and a driven pulley 407.

[0062] This carriage 403 is equipped with a liquid ejection unit 440 that integrates a head 1, which is a liquid ejection head according to the present invention, and a head tank 441. The head 1 of the liquid ejection unit 440 ejects liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The liquid ejection head 1 is mounted with a nozzle row consisting of multiple nozzles arranged in a sub-scanning direction perpendicular to the main scanning direction, and the ejection direction facing downward. The liquid ejection head 1 is connected to a liquid circulation device, which circulates and supplies liquid of the required color.

[0063] The printing device 500 is equipped with a transport mechanism 495 for transporting paper 410. The transport mechanism 495 includes a transport belt 412, which is a transport means, and a sub-scanning motor 416 for driving the transport belt 412. The transport belt 412 attracts the paper 410 and transports it at a position facing the head 1. The transport belt 412 is an endless belt that is stretched between a transport roller 413 and a tension roller 414. The attraction can be achieved by electrostatic attraction or air suction. The transport belt 412 moves in a circular motion in the sub-scanning direction as the transport roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0064] Furthermore, a maintenance and recovery mechanism 420 that maintains and recovers the liquid ejection head 1 is disposed on one side of the carriage 403 in the main scanning direction, beside the conveyor belt 412. The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface of the head 1, a wiper member 422 that wipes the nozzle surface, and the like. The main scanning movement mechanism 493, maintenance and recovery mechanism 420, and conveyor mechanism 495 are attached to a housing that includes side plates 491A and 491B and a back plate 491C.

[0065] In the printing device 500 configured in this manner, the paper 410 is fed onto and adsorbed to the conveyor belt 412, and the paper 410 is conveyed in the sub-scanning direction by the circular movement of the conveyor belt 412. Then, by driving the head 1 in accordance with an image signal while moving the carriage 403 in the main scanning direction, liquid is ejected onto the stationary paper 410 to form an image.

[0066] Next, another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 22 is a plan view illustrating the main parts of the liquid discharge unit of this example.

[0067] This liquid ejection unit 440 is composed of the components that make up the device that ejects the liquid, including a housing portion consisting of side plates 491A, 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a head 1.

[0068] It is also possible to configure a liquid discharge unit in which the above-described maintenance and recovery mechanism 420 is further attached to, for example, the side plate 491B of this liquid discharge unit 440.

[0069] Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 23 is an explanatory front view of the liquid discharge unit of this example.

[0070] This liquid discharge unit 440 is composed of a head 1 to which a flow path part 444 is attached, and a tube 456 connected to the flow path part 444 .

[0071] The flow path part 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path part 444. A connector 443 for electrically connecting with the liquid ejection head 1 is provided on the upper part of the flow path part 444.

[0072] In the present application, the liquid to be ejected may have a viscosity and surface tension that allows it to be ejected from the head, and is not particularly limited, but preferably has a viscosity of 30 mPa·s or less at room temperature and normal pressure, or upon heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or the like, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural colorant, and the like. These liquids can be used, for example, as inkjet inks, surface treatment liquids, liquids for forming components of electronic devices or light-emitting elements, or electronic circuit resist patterns, and material liquids for 3D modeling.

[0073] Energy sources for ejecting liquid include piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators consisting of a vibration plate and an opposing electrode.

[0074] A "liquid ejection unit" is a liquid ejection head integrated with functional parts and mechanisms, and includes a collection of parts related to ejecting liquid. For example, a "liquid ejection unit" includes a liquid ejection head combined with at least one of the following components: a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, a main scanning movement mechanism, and a liquid circulation device.

[0075] Here, "integrated" includes, for example, a liquid ejection head and a functional part or mechanism that are fixed to each other by fastening, bonding, engaging, etc., or one that is held movably relative to the other. The liquid ejection head, functional part, or mechanism may also be configured to be detachable from each other.

[0076] For example, some liquid ejection units have a liquid ejection head and a head tank integrated together, while others have a liquid ejection head and a head tank integrated together by being connected to each other by a tube, etc. Here, a unit including a filter can be added between the head tank and the liquid ejection head of these liquid ejection units.

[0077] Furthermore, there is a liquid ejection unit in which the liquid ejection head and the carriage are integrated.

[0078] In some liquid ejection units, the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated together. In other liquid ejection units, the liquid ejection head, the carriage, and the main scanning movement mechanism are integrated together.

[0079] Furthermore, there is a liquid ejection unit in which a cap member, which is part of the maintenance and recovery mechanism, is fixed to a carriage on which a liquid ejection head is attached, thereby integrating the liquid ejection head, carriage, and maintenance and recovery mechanism.

[0080] In some liquid ejection units, a tube is connected to a head tank or a liquid ejection head equipped with a flow path component, integrating the liquid ejection head with a supply mechanism. Liquid is supplied from a liquid reservoir to the liquid ejection head via this tube.

[0081] The main scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0082] Here, the "liquid ejection unit" is described in combination with a liquid ejection head, but the "liquid ejection unit" also includes a head module or head unit that includes the liquid ejection head described above, and that integrates the functional components and mechanisms described above.

[0083] "Liquid ejection devices" include devices that are equipped with a liquid ejection head, a liquid ejection unit, a head module, a head unit, etc., and that eject liquid by driving the liquid ejection head. Liquid ejection devices include not only devices that can eject liquid onto objects to which the liquid can adhere, but also devices that eject liquid into air or liquid.

[0084] This "liquid ejecting device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0085] For example, examples of "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0086] Furthermore, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0087] The above-mentioned "object onto which a liquid can adhere" means an object onto which a liquid can adhere at least temporarily, an object onto which the liquid can adhere and stick, an object onto which the liquid can penetrate, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which a liquid can adhere.

[0088] The material of the "substance to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0089] Furthermore, the "liquid ejection device" may be a device in which a liquid ejection head and an object onto which liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which a liquid ejection head moves, and a line type device in which a liquid ejection head does not move.

[0090] Other examples of "liquid ejecting devices" include a treatment liquid application device that ejects a treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and an injection granulation device that ejects a composition liquid in which raw materials are dispersed through a nozzle to granulate fine particles of the raw materials.

[0091] In the present application, the terms image formation, recording, printing, copying, printing, modeling, etc. are all synonymous.

[0092] The above description is merely an example, and each of the following aspects provides unique effects. [First aspect] The first aspect is a liquid ejection head 1 that ejects liquid (e.g., ink) in each pressure chamber 21 supplied from a liquid flow path (e.g., individual supply flow path 22) from each nozzle 11 by driving an electromechanical conversion element (e.g., piezoelectric element 40) on an actuator substrate (e.g., individual flow path member 20 and vibration plate member 30), and is characterized by having a damper member 60 that absorbs pressure fluctuations in the liquid flow path by a damper film 66 formed on a damper frame substrate 65. A typical damper member is constructed by overlapping a damper plate on a damper frame substrate in which a displacement space (for example, gap 64) is formed to allow the damper plate to be displaced, and then bonding the two together with an adhesive. However, with adhesive bonding methods, variations in the alignment accuracy between the damper plate and the damper frame substrate and variations in the amount of adhesive that spills into the displacement space are unavoidable, resulting in large variations in damper function and variations in liquid ejection accuracy. On the other hand, conventional liquid ejection heads, which bond a damper plate and a damper frame substrate made of ceramic materials (green sheets) together by sintering, do not use adhesive, resulting in no variation in the amount of adhesive spilling into the displacement space. However, because the damper plate, which is a separate component, must be superimposed on the damper frame substrate, the damper plate must be thick enough to ensure the rigidity required during the superimposition process, making it difficult to thin the damper plate. In recent years, liquid ejection heads have become increasingly miniaturized, and thinner damper plates are required to achieve sufficient damping function. However, conventional liquid ejection heads have difficulty achieving the damping function required for miniaturization, making it difficult to achieve high liquid ejection accuracy from each nozzle. In this embodiment, the damper member is configured by depositing a damper film on a damper frame substrate. In this configuration, by using film-deposition techniques from semiconductor manufacturing processes, it is possible to deposit a thin damper film on the damper frame substrate with high precision. Therefore, the liquid ejection head of this embodiment can be equipped with a damper member that can achieve the damping function required for liquid ejection heads that are becoming increasingly miniaturized. Therefore, according to this embodiment, even in liquid ejection heads with fine structures, the damper member can properly function, achieving high liquid ejection precision.

[0093] [Second mode] The second aspect is characterized in that in the first aspect, the damper film is a laminated film made up of a plurality of layers 66a to 66c made of different materials. This makes it easier to control the stress and stiffness of the damper film 66 .

[0094] [Third aspect] The third aspect is characterized in that, in the second aspect, the plurality of layers include a layer in which compressive stress occurs (e.g., silicon oxide films 66a, 66c) and a layer in which tensile stress occurs (e.g., silicon nitride film 66b). When a large compressive stress acts on the damper membrane 66, the damper membrane 66 buckles and breaks or wrinkles after forming a displacement space (e.g., void 64) to allow displacement of the damper plate. On the other hand, when a large tensile stress acts on the damper membrane 66, excessive tension is generated in the damper membrane 66, causing the damper membrane 66 to break. According to this embodiment, it is easy to control the stress acting on the damper membrane 66 within an appropriate range (stress control).

[0095] [Fourth aspect] The fourth aspect is characterized in that, in any of the first to third aspects, the stress of the damper film is 50 [MPa] or less if it is a compressive stress, and 150 [MPa] or less if it is a tensile stress. Within this stress range, the necessary damping function can be ensured, and damage to the damper film 66 due to stress can be suppressed.

[0096] [Fifth mode] A fifth aspect is characterized in that in any one of the first to fourth aspects, the damper film is made of an inorganic material. This allows for a high degree of freedom in the selection of construction methods, since there are no restrictions on the thermal history of the construction methods that are required when using a resin material for the damper film.

[0097] [Sixth aspect] A sixth aspect is a liquid ejection unit, characterized in that it includes the liquid ejection head according to any one of the first to fifth aspects. According to this aspect, it is possible to provide a liquid ejection unit in which the damper member functions appropriately and high liquid ejection accuracy can be obtained even in a liquid ejection head having a fine structure.

[0098] [Seventh aspect] A seventh aspect is a device for ejecting liquid, characterized in that it comprises the liquid ejection head of any one of the first to fifth aspects or the liquid ejection unit of the sixth aspect. According to this aspect, it is possible to provide a liquid ejection device in which the damper member functions appropriately even in a liquid ejection head having a fine structure, and high liquid ejection accuracy can be obtained.

[0099] [Eighth aspect] The eighth aspect is a manufacturing method for a liquid ejection head 1 in which liquid (e.g., ink) in each pressure chamber 21 supplied from a liquid flow path (e.g., individual supply flow path 22) is ejected from each nozzle 11 by driving an electromechanical conversion element (e.g., piezoelectric element 40) on an actuator substrate (e.g., individual flow path member 20 and vibration plate member 30), and pressure fluctuations in the liquid flow path are absorbed by a damper member 60, characterized in that the damper member 60 is formed by depositing a damper film 66 on a damper frame substrate 65. According to this aspect, it is possible to provide a liquid ejection head in which the damper member functions properly and high liquid ejection accuracy can be obtained even in a liquid ejection head having a fine structure.

[0100] [Ninth aspect] The ninth aspect is characterized in that in the eighth aspect, a damper film constituting layer (e.g., silicon oxide film 66a) that constitutes the damper film is formed on a sacrificial layer (e.g., active layer 65b) formed on the damper frame substrate, and then a portion of the sacrificial layer is removed to form a displacement space (e.g., void 64) for the damper film. According to this aspect, it is possible to provide a liquid ejection head in which the damper member functions properly and high liquid ejection accuracy can be obtained even in a liquid ejection head having a fine structure.

[0101] [Tenth aspect] The tenth aspect is characterized in that in the ninth aspect, the space-forming hole (e.g., void-forming hole 64b) formed in the damper film-constituting layer to remove a portion of the sacrificial layer is sealed by another damper film-constituting layer (e.g., silicon oxide film 66c) stacked on top of the damper film-constituting layer. If the space-forming holes are left unsealed, it becomes difficult to employ existing general construction methods in subsequent processes. However, according to this embodiment, the space-forming holes are sealed, so existing general construction methods can be employed in subsequent processes. Furthermore, because the space-forming holes can be sealed during the damper film formation process, an additional sealing process is not required. Therefore, the manufacturing process can be simplified and manufacturing costs can be reduced.

[0102] [Eleventh aspect] The eleventh aspect is a method in which, in the ninth or tenth aspect, the sacrificial layer is formed on the damper frame substrate, a partition-forming hole (e.g., barrier layer filling groove 65c) is formed between a part of the sacrificial layer (e.g., the part that will become the gap 64) and another part (e.g., the part that will become the gap partition 67) and then the damper film-constituting layer is formed and the partition-forming hole is filled with the damper film-constituting layer, and then the part of the sacrificial layer is removed by etching (sacrificial layer removal method), and the sacrificial layer is characterized by having a high etching rate relative to the damper film-constituting layer. This makes it possible to prevent the remaining portion (e.g., gap partition 67) of the sacrificial layer from being etched away when the portion of the sacrificial layer that will become the displacement space (e.g., gap 64) is removed by etching.

[0103] [12th aspect] A twelfth aspect is the liquid ejection head of the eleventh aspect, characterized in that the sacrificial layer is silicon, and the damper film constituent layer is a silicon oxide film. According to this embodiment, as described in the first modification, the damper member 60 can be manufactured using an inexpensive silicon wafer, thereby reducing the manufacturing cost.

[0104] [13th aspect] A thirteenth aspect is the liquid ejection head of the eleventh aspect, characterized in that the sacrificial layer is a silicon oxide film, and the damper film constituent layer is a silicon film or a polysilicon film. According to this embodiment, as described in the second modification, the damper member 60 can be manufactured using an inexpensive silicon wafer, thereby reducing the manufacturing cost. [Explanation of symbols]

[0105] 1: Liquid ejection head 10: Nozzle plate 11: Nozzle 20: Individual flow path member 21: Pressure chamber 22: Individual supply channel 23: Individual collection channel 25: Individual flow path 30: Diaphragm member 31: Vibration plate 32: Supply side opening 33: Collection side opening 40: Piezoelectric element 50: Common flow path member 52: Common supply channel tributary 53: Common collection channel tributary 54: Supply port 55: Collection port 56: Main common supply channel 57: Main common recovery channel 60: Damper member 61: Through hole 62: Supply side damper 63: Recovery side damper 64 :Void 64a :Void bulkhead 64b: Void forming hole 65: Damper frame board 65a:BOX layer 65b:Active layer 65c: Barrier layer filling groove 65d: Silicon oxide film 66: Damper membrane 66a: Silicon oxide film 66a': Polysilicon film 66b: Silicon nitride film 66c: Silicon oxide film 67:Void bulkhead 68: Atmospheric communication part 69: Liquid-resistant membrane 80: Frame member 100: Head module 101: Flexible wiring material 102: Drive circuit 103: Base member 104: Heat dissipation material 105: Manifold 107: Module case 440: Liquid dispensing unit 500:Printing device [Prior art documents] [Patent documents]

[0106] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-36539

Claims

1. A liquid ejection head that ejects liquid from each nozzle by driving an electromechanical conversion element on an actuator substrate, the liquid being supplied from each pressure chamber through a liquid flow path, A liquid ejection head characterized by comprising a damper member that absorbs pressure fluctuations within the liquid flow path by displacing a damper film formed on a damper frame substrate within a displacement space formed between the damper frame substrate and the damper film.

2. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the damper film is a laminated film made up of a plurality of layers made of different materials.

3. 3. The liquid ejection head according to claim 2, The liquid ejection head is characterized in that the plurality of layers include a layer in which compressive stress occurs and a layer in which tensile stress occurs.

4. 4. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the stress of the damper film is 50 MPa or less if it is a compressive stress, and 150 MPa or less if it is a tensile stress.

5. 5. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the damper film is made of an inorganic material.

6. A liquid ejection unit comprising the liquid ejection head according to claim 1 .

7. 7. A liquid ejection device comprising: a liquid ejection head according to claim 1; or a liquid ejection unit according to claim 6.

8. A method for manufacturing a liquid ejection head in which liquid in each pressure chamber supplied from a liquid flow path is ejected from each nozzle by driving an electromechanical conversion element on an actuator substrate, and pressure fluctuations in the liquid flow path are absorbed by a damper member, forming a damper film on a damper frame substrate to form the damper member; A method for manufacturing a liquid ejection head, characterized in that in the above process, a damper film constituting layer that constitutes the damper film is formed on a sacrificial layer formed on the damper frame substrate, and then a portion of the sacrificial layer is removed to form a displacement space for the damper film.

9. The method for manufacturing a liquid ejection head according to claim 8, A method for manufacturing a liquid ejection head, characterized in that a space-forming hole formed in the damper film constituent layer in order to remove a portion of the sacrificial layer is sealed with another damper film constituent layer laminated on top of the damper film constituent layer.

10. 10. The method for manufacturing a liquid ejection head according to claim 8, forming the sacrificial layer on the damper frame substrate, forming a partition wall-forming hole between the part and another part of the sacrificial layer, then forming the damper film constituting layer to fill the partition wall-forming hole with the damper film constituting layer, and then removing the part of the sacrificial layer by etching; The method for manufacturing a liquid ejection head, wherein the sacrificial layer has a high etching rate relative to the damper film forming layer.

11. 11. The method for manufacturing a liquid ejection head according to claim 10, The method for manufacturing a liquid ejection head, wherein the sacrificial layer is made of silicon, and the damper film forming layer is made of silicon oxide.

12. 11. The method for manufacturing a liquid ejection head according to claim 10, The method for manufacturing a liquid ejection head, wherein the sacrificial layer is a silicon oxide film, and the damper film constituent layer is a silicon film or a polysilicon film.

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