JP2007001297A - Liquid discharge head and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress reduction in rigidity of a substrate of a liquid discharge head having high-density nozzles. <P>SOLUTION: The liquid discharge head of this invention has a plurality of pressure generating chambers 102 having respective pressure generating elements, a plurality of nozzle openings 113 which are respectively communicated with the plurality of pressure generating chambers 102 and discharge liquid, and a reservoir 108 commonly communicated with the plurality of pressure generating chambers 102 respectively via communicating portions. The pressure generating chambers 102 and the reservoir 108 have recessed portions respectively formed on a principal surface of two principal surfaces of a same substrate 100 and the other principal surface. In the reservoir, a portion having a depth less than that of a communicating portion vicinity portion 107 of the communication portion in the reservoir 108 is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid discharge head used in a liquid discharge recording apparatus that forms an image on a recording medium by discharging droplets with discharge energy generated from a pressure generating element, and a method for manufacturing the same.

  Liquid discharge type recording devices that form droplets and eject images onto the recording medium are complex and require precision microfabrication associated with the increase in the number of nozzles in order to meet the demands for high-quality and high-definition recording. Is needed. In view of this, there has been proposed an ink jet head manufacturing method using a micromachining technique that can easily form a fine and complicated shape on a single crystal Si substrate using anisotropic etching or the like.

  For example, FIG. 8 shows a method for manufacturing an inkjet head disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 5-229128). The channel substrate 500 is a silicon single crystal substrate. By performing two-step anisotropic etching on one surface of the flow path substrate 500, ink flow paths such as a nozzle 501, a pressure generation chamber 502, an ink supply port 503, and a reservoir 504 are integrally formed.

FIG. 9 shows a method for manufacturing an ink jet head disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 10-209113). When forming a groove by anisotropic etching using the Si (110) single crystal substrate 600, the area dependency of the etching rate is reduced by using the mask pattern 601 for groove formation. The process is shown in FIG. Etching with a mask pattern 601 having an opening 602 forms a narrow groove 603 as shown in FIG. 9B. Subsequently, as shown in FIG. 9C, the silicon portion 604 between the narrow-width grooves 603 is removed by etching to form a wide-width groove 605 as shown in FIG. 9D.
Japanese Patent Laid-Open No. 5-229128 Japanese Patent Laid-Open No. 10-209113

  The manufacturing method disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 5-229128) utilizes the crystal orientation dependence of the etching rate, so that a reservoir with high formation accuracy can be formed, but can be used. A process restriction may occur because the plane orientation of the silicon single crystal substrate is limited.

  In addition, if the high density nozzle is formed by anisotropic etching of the Si (100) substrate in order to form the reservoir in the silicon single crystal substrate, the substrate thickness is inevitably reduced. For this reason, it becomes difficult to ensure the rigidity of the substrate, and the yield cannot be improved, and the durability and stability of the head cannot be achieved. In particular, when a Si (110) substrate is used, it is expected that it will be more difficult in terms of process, such as limiting the degree of freedom in shape and requiring a multi-stage mask layer for adjusting the reservoir depth.

  The manufacturing method disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 10-209113) uses crystal anisotropic etching of a Si (110) single crystal substrate. In this case as well, there are cases where process restrictions may occur because the plane orientation of the usable Si single crystal substrate is limited.

  In particular, when a groove having a complicated shape other than a rectangle is desired, the depth of the bottom surface of the etching is different in the etching opening region, or a relatively large etching depth is required, the desired formation accuracy is satisfied. There is a risk of disappearing.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a liquid discharge head that suppresses a decrease in substrate rigidity and a method for manufacturing the same.

  A liquid discharge head according to the present invention includes a plurality of pressure generation chambers each including a pressure generation element, a plurality of nozzle ports that respectively communicate with the plurality of pressure generation chambers and discharge liquid, and the plurality of pressure generation chambers Each of the pressure generating chamber and the reservoir are respectively connected to one main surface and the other main surface of the two main surfaces of the same substrate. A portion having a formed recess and having a shallower depth in the reservoir near the communicating portion in the vicinity of the communicating portion is provided in the reservoir.

  In the present invention, as described above, a portion shallower than the depth of the communication portion near the communication portion in the reservoir is provided in the reservoir, so that the rigidity of the portion of the substrate where the reservoir is provided is inadvertently reduced. There is nothing to do.

  An embodiment of a method for manufacturing a liquid ejection head according to the present invention will be described with reference to the drawings.

  In order to form the reservoir of the liquid discharge head by plasma etching processing, for example, dry etching processing using ICP discharge (Inductively Coupled Plasma) (hereinafter referred to as “ICP discharge etching processing”) is used, which is substantially perpendicular to the surface of the Si substrate. A groove having a side wall is formed. Since it is a plasma etching process, there is no limitation on the plane orientation of the Si single crystal substrate to be used, but a Si (100) substrate is usually used.

  FIG. 1 is a process diagram illustrating a method for manufacturing a liquid ejection head according to an embodiment.

  (1) As shown in FIG. 1A, an opening corresponding to the pressure generation chamber 12 and the rear diaphragm 20 which is a communication portion is formed on one main surface (A surface) of the two main surfaces of the substrate 10. An etching mask pattern 11 is formed. Further, the first etching mask pattern 14 having an opening corresponding to the reservoir 18 as the first layer is formed on the other main surface (B surface) of the substrate 10. Further, a second etching mask pattern 16 having an opening that can etch only the communication portion where the rear diaphragm 20 is opened inside the reservoir and the communication portion vicinity portion 17 including the vicinity thereof is formed as the second layer above it.

  (2) After the above step (1), ICP discharge etching using the etching mask pattern 11 is performed on the A surface side of the substrate 10 to form recesses corresponding to the pressure generation chamber 12 and the rear diaphragm 20.

  (3) After the step (2), by performing ICP electric discharge etching processing using the second etching mask pattern 16 on the B surface side of the substrate 10, the communication portion in the recess corresponding to the reservoir 18 and its vicinity A recess corresponding to the communication portion vicinity portion 17 is formed.

  (4) After the above step (3), as shown in FIG. 1B, after the second etching mask pattern 16 on the B surface side is removed by etching, ICP discharge etching processing using the first etching mask pattern 14 is performed. To form a recess corresponding to the reservoir 18.

  Thus, the communication part vicinity part 17 formed using the 2nd etching mask pattern 16 has taken the form deeper (closer to A surface) than the recessed part formed using the 1st etching mask pattern 14. Therefore, it reliably communicates with the aperture 20 formed on the surface of the substrate A. Therefore, it is not necessary to over-etch the recesses formed using the first etching mask pattern 14 more than necessary, and the rigidity deterioration of the substrate can be suppressed.

  In this embodiment, as the etching mask pattern, the type of etching mask pattern can be selected as long as it has selectivity at the time of ICP electric discharge etching processing and can selectively remove the first layer and the second layer. It doesn't matter. For example, the first layer may be formed by patterning a thermal oxide film, and the second layer may be formed by patterning a resist. In this case, both etching mask patterns have a high etching selectivity with respect to Si. Regarding the removal of the etching mask pattern, the resist can be selectively removed with oxygen plasma and the thermal oxide film can be selectively removed with BHF (Buffered Hydrogen Fluoride).

  FIG. 2 is a process diagram illustrating a method for manufacturing a liquid ejection head according to another embodiment.

  (1) In the present embodiment, as shown in FIG. 2A, a plurality of small openings arranged in a mosaic pattern at intervals in the region corresponding to the reservoir 58 on the B surface side of the substrate 50. An etching mask pattern 56 having a portion is formed.

  (2) After the step (1), ICP discharge etching is performed to form a plurality of columnar bodies 59 arranged in a mosaic pattern at intervals in the recess corresponding to the reservoir 58.

  (3) After the step (2), as shown in FIG. 2C, isotropic etching such as TMAH (Tetra methyl ammonium hydroxide) is performed to remove the plurality of columnar bodies 59.

  According to this embodiment, it is possible to reduce uneven etching depth in the recess corresponding to the reservoir during ICP electric discharge etching processing, and to form a flat etching bottom surface. In this case, the minute protrusions 60 are formed in a mosaic shape in the recesses corresponding to the reservoir 58 on the etching bottom surface, but this is not a problem level. When TMAH is used for the isotropic etchant, a thermal oxide film may be used as an etching mask pattern used in ICP discharge etching.

  Further, the shape of the small openings arranged in a mosaic pattern of the etching mask pattern may be a uniform shape or a combination of shapes having different areas. In the case of a uniform shape, the etching rate is less dependent on the area, and as a result, the same depth is formed.

  In the case of shapes having different areas, it is possible to form a step shape on the bottom surface of the recess by utilizing the fact that the larger opening area has a relatively high etching rate and is easily etched.

  Note that an etchant for performing isotropic etching can be used with a mixed acid of (hydrofluoric acid, acetic acid, nitric acid), an etching gas containing F as a main component, or the like if there is no problem in the process step. As the etching mask pattern layer at that time, one that is possible in view of the above process is used.

  Typical examples of the pressure generating element include a piezoelectric film or an electrostrictive element, a heat generating element, an electrostatic force, and the like.

  As a method for forming a piezoelectric film or an electrostrictive film on a diaphragm, a piezoelectric film or an electrostrictive film formed on a film formation substrate is bonded and bonded by an adhesive or anodic bonding, and then the film formation substrate is peeled off. May be. Alternatively, after forming the lower electrode directly on the diaphragm, the piezoelectric film or the electrostrictive film may be formed using a film forming means that is within the temperature range allowed by the structure and that can be seen from the process step. For example, sputtering, CVD, sol-gel, EB vapor deposition, laser ablation, or the like is used.

Examples of materials used for the piezoelectric film or the electrostrictive film include perovskite compounds. For example, it is a piezoelectric material such as lead zirconate titanate PZT [Pb (ZrxTi1-x) O ₃ ] or barium titanate BaTiO ₃ or an electrostrictive material of a relaxor-based material. MP of lead zirconate titanate (PZT) preferably has a meso phase boundary (MPB) composition of 0.40 to 0.65, but other composition ratios may be used. The crystal structure of PZT may be either tetragonal or rhombohedral. BaTiO ₃ is tetragonal (001) oriented film is preferred. BaTiO ₃ may contain a trace amount of lead and bismuth.

  The following can be selected as the electrostrictive material used in the present invention.

For example, PMN [Pb (MxNb1-x) O ₃ ], PNN [Pb (NbxNi1-x) O ₃ ], PSN [Pb (ScxNb1-x) O ₃ ], PZN [Pb (ZxNb1-x) O ₃ ], PMN-PT {(1-y ) [Pb (MgxNb1-x) O 3] -y [PbTiO 3]}, PSN-PT
{(1-y) [Pb (ScxNb1-x) O 3] -y [PbTiO 3]}, PZN-PT {(1-y) [Pb (ZnxNb1-x) O 3] -y [PbTiO 3]} , LN [LiNbO ₃ ], KN [KNbO ₃ ]. Here, x and y are numbers of 1 or less and 0 or more. For example, x is 0.2 to 0.5 in the case of PMN, x is preferably 0.4 to 0.7 in PSN, y of PMN-PT is 0.2 to 0.4, and y of PSN-Pt is 0.35-0.5, y of PZN-PT is preferably 0.03-0.35. PMN-PT,
PMN-PZT, PZN-PZT, PNN-PZT, and PSN-PZT compounds in which Zr is substituted for Ti in PZN-PT, PNN-PT, and PSN-PT may be used.

  The piezoelectric film or the electrostrictive film may have a single composition or a combination of two or more. Moreover, the composition which doped the trace amount element to the said main component may be sufficient. The piezoelectric film or the electrostrictive film is preferably crystal-controlled in order to exhibit excellent piezoelectricity, and preferably has a specific orientation of a specific crystal structure of 50% or more by X-ray diffraction, More than 90% is more preferable.

  As a material for forming the diaphragm, a metal such as nickel or chromium is suitable in addition to borosilicate glass (SD2 glass manufactured by HOYA Corporation), silicon oxide, and ceramic material. In the vibration plate forming step, a thick plate-like vibration plate member is joined to the flow path forming substrate to reduce the thickness. Alternatively, it is possible to remove the support substrate by forming a diaphragm on the support substrate and then transferring and bonding it to the flow path forming substrate side. Here, it is preferable to use anodic bonding or solid phase bonding utilizing bonding / thermal diffusion between atoms for bonding the member including the diaphragm and the flow path forming substrate. Typical methods in solid phase bonding include Au bonding and AuSn alloy bonding. The piezoelectric actuator or the electrostrictive actuator may have a thin film configuration using a deflection displacement of a diaphragm.

  Specific examples are shown below, but the dimensions, shapes, materials, driving conditions, etc. of the pressure generating element, diaphragm, pressure generating chamber, rear throttle, reservoir, nozzle connection port, nozzle port, etc. are examples, and the design It can be arbitrarily changed as a matter. Here, the rear throttle is in communication with the pressure generating chamber as a rear resistance element, and the nozzle communication port is a flow path in communication with the nozzle port.

  FIG. 3 is a process diagram for explaining the method of manufacturing the liquid discharge head according to the first embodiment of the present invention.

  As shown in FIG. 3E, the liquid discharge head of this embodiment is formed in a pressure generating chamber 102 (width 60 μm, depth 50 μm) on a Si single crystal substrate (hereinafter referred to as “substrate”) 100 having a thickness of 200 μm. , 2.5 mm in length), a reservoir 108, a rear throttle 110 serving as a communication portion, and a nozzle communication port 103 are formed. A nozzle plate 114 having a nozzle port 113 having a 300 dpi nozzle density is bonded and fixed with an adhesive so that the nozzle port 113 and the nozzle connection port 103 on the substrate side communicate with each other.

The actuator used was 3 μm-thick borosilicate glass (SD2 glass manufactured by HOYA Corporation) as the diaphragm 112. An upper Pt film (100 nm thickness) / Pb (Zr _0.52 Ti _0.48 ) O ₃ film (1 μm thick) / lower Pt film (100 nm thickness) is formed thereon as the piezoelectric film 111. Both the lower electrode and the upper electrode are wired to the driving IC so that each actuator can be driven independently.

  Next, a method for manufacturing the liquid discharge head according to the present embodiment will be described in detail with reference to FIG.

  (1) As shown in FIG. 3A, a thermal oxide film (1 μm) is provided on the A surface side of the substrate 100, which is one of the two main surfaces of the same substrate, and corresponds to the pressure generating chamber 102. An etching mask pattern 101 having an opening corresponding to the rear aperture 110 and an opening corresponding to the rear diaphragm 110 is formed. A second surface having the opening corresponding to the reservoir 108 and the opening corresponding to the nozzle communication port 103 is formed on the B surface side of the substrate 100 which is the other main surface of the two main surfaces of the same substrate. One etching mask pattern 104 is formed. A second etching mask pattern 106 having an opening corresponding to the nozzle communication port 103 and an opening corresponding to the communication portion neighboring portion 107 in the reservoir is formed thereon as a second layer with a resist film (1.5 μm). .

  (2) After the step (1), the pressure generating chamber 102 is etched to a depth of 50 μm by ICP discharge etching. Next, as shown in FIG. 3B, the second etching mask pattern 106 is used only for the concave portion corresponding to the B-side nozzle communication port 103 and the communication portion neighboring portion 107 in the concave portion corresponding to the reservoir. Etching is performed by ICP electric discharge etching to a depth of 10 μm.

  (3) After the step (2), as shown in FIG. 3C, the resist film of the second etching mask pattern 106 on the B surface side is etched away with oxygen plasma. Next, the first etching mask pattern 104 is used to perform ICP discharge etching on the B surface side so that the reservoir 108 and the rear stop 110 are communicated with each other through the communication portion vicinity portion 107.

  In the ICP electric discharge etching process, since the etching rate shows an area-dependent relationship, the reservoir 108 having a relatively larger area than the nozzle communication port 103 communicates with the rear throttle 110 first.

  (4) After the above step (3), as shown in FIG. 3 (d), a mask layer 109 made of resist is disposed in the communicating reservoir 108 to prevent etching, and the nozzle communication port 103 (depth 150 μm) continues. ) To be communicated with the pressure generating chamber 102. After that, the thermal oxide film of the first etching mask pattern 104 existing on both surfaces of the substrate 100 is removed by etching with BHF.

  (5) After the step (4), as shown in FIG. 3E, an actuator having the diaphragm 112 and the piezoelectric film 111 is formed as follows. Here, in FIG. 3E, a schematic view of the head not provided with the diaphragm 112 and the piezoelectric film 111, as viewed from the A surface of the substrate, is shown in FIG. The plurality of pressure generation chambers 102 have reservoirs 108 that are commonly communicated with each other via a rear throttle 110 that is a communication portion.

Borosilicate glass (SD2 glass manufactured by HOYA Co., Ltd.) flat-polished to about 30 μm is anodically bonded to the pressure generation chamber 102 side of the substrate 100 under the conditions of 400 ° C. and 400V. Thereafter, the diaphragm 112 is formed by thinning into a thickness of 3 μm by wet etching using HF. An upper Pt film (100 nm thickness) / Pb (Zr _0.52 Ti _0.48 ) O ₃ film (1 μm thick) / lower Pt film (100 nm thickness) is formed thereon by vacuum film formation. Before the upper Pt electrode is formed, the PZT film is baked in an oxygen atmosphere at 680 ° C. for 5 hours, and crystallization of the PZT film is confirmed by XRD. The wiring pattern is processed by a photolithography process or a dry etching process.

  Finally, the nozzle plate 114 is bonded and fixed as follows. The nozzle plate 114 is formed by punching a SUS304 having a thickness of 50 μm and forming a nozzle port 113 (discharge φ20 μm, reverse side φ50 μm). The adhesive was spin-coated on the nozzle plate 114 side, aligned and fixed based on the alignment markers on both the nozzle plate 114 and the substrate 100, and bonded at 70 ° C. for about 30 minutes.

  According to the present embodiment, by adjusting the depth of the partial region of the recess corresponding to the reservoir 108, it is not necessary to over-etch the central portion depth of the reservoir 108 more than necessary. In this way, it is possible to provide a liquid ejection head that has higher processing accuracy than the prior art and has excellent durability and reliability during ink ejection.

  FIG. 5 is a process diagram illustrating a method for manufacturing a liquid discharge head according to the second embodiment of the present invention.

  As shown in FIG. 5 (f), the liquid discharge head of the present example includes a 300 μm thick Si single crystal substrate (hereinafter referred to as “substrate”) 200, a reservoir 208, a pressure generation chamber 202 (width 60 μm, Depth 50 μm, length 2.5 mm), a rear stop 210 and a nozzle communication port 203 are formed. Although the basic configuration is the same as that of the first embodiment, the nozzle port 213 is integrally formed in the substrate 200 so as to communicate with the nozzle communication port 203. The actuator having the diaphragm 212 and the piezoelectric film 211 is the same as that in the first embodiment.

  Next, a manufacturing method of the liquid discharge head according to the present embodiment will be described in detail with reference to FIG.

  (1) In this embodiment, since the nozzle port is formed on the same substrate, the nozzle communication port 203 is formed from the pressure generating chamber 202 side as shown in FIG. A first etching mask pattern 201 having openings corresponding to the pressure generation chamber 202 and the rear diaphragm 210 is formed on the surface A side of the substrate 200 with a thermal oxide film (1 μm). A photoresist (4 μm) is applied on the upper layer to form a second etching mask pattern 206 a having an opening corresponding to the nozzle connection port 203.

  Further, a first etching mask pattern 204 having openings corresponding to the nozzle port 213 and the reservoir 208 is formed on the surface B side of the substrate 200 with a thermal oxide film (1 μm). A photoresist (4 μm) is applied to the upper layer to form a second etching mask pattern 206 b having openings corresponding to the communication port vicinity 207 in the recess corresponding to the nozzle port 213 and the reservoir 208.

  (2) After the above step (1), a 200 μm deep recess corresponding to the nozzle connection port 203 (50 × 200 μm square area) is etched by ICP electric discharge etching using the second etching mask pattern 206a on the A side. To do.

  (3) After the step (2), as shown in FIG. 5B, the resist film of the second etching mask pattern 206a on the A surface side is stripped with oxygen plasma. Next, a recess having a depth of 50 μm corresponding to the pressure generation chamber 202 is formed using the first etching mask pattern 201 having openings corresponding to the pressure generation chamber 202 and the rear diaphragm 310. ICP discharge etching is used to form the recess. Since a recess having a depth corresponding to the nozzle communication port 203 has already been formed, the pressure generation chamber 202 and the nozzle communication port 203 communicating with each other in the same substrate are formed by this etching process.

  (4) After the step (3), as shown in FIG. 5 (c), to form the nozzle opening 213 on the B surface side, the reservoir 208, and the communication portion vicinity portion 207 in the vicinity of the communication portion in the reservoir, As in the previous step, multi-stage ICP electric discharge etching processing is performed using a two-layer etching mask pattern. First, using the second etching mask pattern 206b, the recess corresponding to the communication portion vicinity portion 207 in the vicinity of the communication portion in the nozzle port 213 and the reservoir 208 is etched to a depth of 25 μm by ICP discharge etching.

  (5) After the above step (4), as shown in FIG. 5 (d), the ICP electric discharge etching process is performed on the B surface side to correspond to the nozzle port 213 having a depth of 50 μm (discharge φ20 μm, reverse φ20 μm). A recess is formed. At this time, the mask layer 209a that protects the communication portion vicinity portion 207 in the reservoir 208 is disposed to prevent the progress of etching.

  (6) After the step (5), as shown in FIG. 5E, the resist film of the second etching mask pattern 206b on the B surface side is etched away with oxygen plasma. Again, in order to prevent the etching of the nozzle port 213 from progressing, the mask layer 209b is used to prevent the progress of etching. After that, the ICP electric discharge etching process is continuously performed using the first etching mask pattern 204 on the B surface side, and the reservoir 208 and the rear stop 210 are communicated with each other via the communication portion vicinity portion 207. Next, the thermal oxide film existing on both surfaces of the substrate is removed by etching with BHF.

  (7) After the step (6), as shown in FIG. 5F, an actuator having the diaphragm 212 and the piezoelectric film 211 is formed in the same procedure as in the first embodiment. Further, the opening of the reservoir 208 is closed with a sealing plate 214.

  As described above, by adjusting the depth of the partial region of the reservoir 208, it becomes unnecessary to over-etch the central portion more than necessary. Further, since the flow path configuration including the nozzle port 213 is formed on the same substrate, there is no occurrence of an adhesion position error or the like at the time of adhesion as in the case of adhering the nozzle plate. As a result, it is possible to provide a liquid discharge head having higher accuracy than the conventional one and having excellent durability and reliability during liquid discharge.

  As shown in FIG. 6F, the liquid discharge head of this embodiment uses a 300 μm thick Si single crystal substrate (hereinafter referred to as “substrate”) 400, a reservoir 408, a pressure generation chamber (width 60 μm). , Depth 50 μm, length 2.5 mm) 402, a rear diaphragm 410, a nozzle communication port 403, and a nozzle port 413 are formed. As in the first embodiment, the basic configuration is that the nozzle port 413 is integrally formed on the substrate 400 side and communicates with the nozzle communication port 403. The actuator having the vibration plate 412 and the piezoelectric film 411 is the same as that in the first embodiment.

  Next, the manufacturing method of the liquid discharge head in the present embodiment will be described in detail.

  (1) In this embodiment, since the nozzle port is formed on the same substrate, the nozzle communication port 403 is formed from the pressure generating chamber 402 side as shown in FIG. A thermal oxide film having a thickness of 1 μm is formed on two main surfaces of the substrate 400. A first etching mask pattern 401 having openings for forming the pressure generation chamber 402 and the rear diaphragm 410 is formed of a thermal oxide film (1 μm) on one main surface (A surface) side. A second etching mask pattern 404 having an opening for forming a nozzle connection port 403 is formed by applying a photoresist (4 μm) thereon. After that, using the second etching mask pattern 404, a 200 μm deep recess corresponding to the nozzle connection port 403 (50 × 200 μm square area) is etched by ICP discharge etching.

  (2) After the above step (1), as shown in FIG. 6B, the resist film of the second etching mask pattern 404 on the A surface side is stripped with oxygen plasma to form the pressure generating chamber 402. The thermal oxide film of the first etching mask pattern 401 is used as an etching surface.

  (3) After the step (2), using the first etching mask pattern 401 on the A surface side, a 50 μm deep recess corresponding to the pressure generating chamber 402 and the rear diaphragm 410 is etched by ICP electric discharge etching. Since a recess having a depth corresponding to the nozzle connection port 403 has already been formed, the pressure generation chamber 402 and the nozzle connection port 403 are formed in the same substrate by this etching process.

  Subsequently, in this embodiment, since an alkali etchant is used when the reservoir 408 is formed, a thermal oxide film 415 is formed to a thickness of 50 nm on the formed channel wall surface.

  (4) After the step (3), the nozzle port 413 and the reservoir 408 are formed as shown in FIG. A second etching mask pattern 406 having openings for forming the nozzle opening 413 and the reservoir 408 on the B surface side of the substrate 400 is formed of a thermal oxide film (1 μm).

  In FIG. 6C, a schematic view seen from the substrate B surface (where the reservoir is formed) is shown in FIG. Here, the mask pattern of the reservoir 408 is formed so as to divide the reservoir formation region into a lattice shape (matrix shape). The lattice pattern is composed of an etching mask pattern 406 having a plurality of small openings arranged in a mosaic pattern at intervals in a region corresponding to the reservoir 408.

  The opening area corresponding to one lattice of the etching pattern formed in the opening corresponding to the communication portion vicinity 407 in the reservoir 408 is formed in the opening corresponding to the reservoir 408 other than the opening corresponding to the communication portion vicinity. It is larger than the corresponding opening area per lattice of the etching pattern to be formed. Specifically, the lattice pattern (opening area) of the etching pattern in the portion corresponding to the reservoir 408 excluding the vicinity of the communicating portion 407 is 50 μm × 50 μm. The width of the etching pattern between the lattices is 5 μm. These are aligned in the region of 850 μm (length direction including each head) × 20 mm (length direction including all heads) of the recess corresponding to the reservoir 408. The lattice pattern (opening area) of the etching pattern in the portion corresponding to the communicating portion neighboring portion 407 in the vicinity of the rear stop 410 that is the communicating portion is 50 μm × 85 μm, and the opening area is larger than the other lattice patterns.

  (5) After the step (4), using the etching mask pattern 406, the recesses corresponding to the nozzle opening 413 and the reservoir 408 are etched by ICP discharge etching until the nozzle depth reaches 50 μm deep. To do. The formed nozzle port 413 has a discharge diameter of 20 μm and a reverse side diameter of 20 μm.

(6) Subsequent to the step (5), ICP electric discharge etching is performed, and as shown in FIG. 6D, the communication portion vicinity portion 407 in the reservoir 408 communicates with the rear throttle 410 on the pressure generation chamber 402 side. . In this embodiment, two types of patterns with different etching areas are provided in the recess corresponding to the reservoir 408 by utilizing the fact that the etching rate depends on the area in the ICP discharge etching process. For this reason, in the reservoir 408, the communication portion vicinity portion 407 in the vicinity of the communication portion in the reservoir 408 having a relatively wide etching opening is etched deeper than the average depth in the reservoir 408. In the above description, the lattice pattern of the portion corresponding to the reservoir 408 excluding the communication portion vicinity 407 is 50 μm × 50 μm, and the lattice pattern of the portion corresponding to the communication portion vicinity portion 407 is 50 μm × 85 μm. However, in order to make the etching rate more prominent, the lattice pattern of the portion corresponding to the reservoir 408 excluding the communication portion vicinity 407 may be 20 μm × 20 μm, and the lattice pattern of the portion corresponding to the communication portion vicinity 407 may be 50 μm × 85 μm. Good. At this time, the nozzle opening 413 is protected by the resist film 411a to prevent the progress of etching.

  (7) After the step (6), as shown in FIG. 6 (e), the formed plurality of support structures 408a are immersed in a TMAH solution at 80 ° C. for about 1 minute and removed by etching. At this time, the nozzle opening 413 is protected using a mask layer 414 and a jig to prevent the progress of etching. After that, the thermal oxide film existing on both surfaces of the substrate 400 is removed by etching with BHF.

  (8) After the step (7), as shown in FIG. 6F, the actuator having the vibration plate 412 and the piezoelectric film 411 is formed in the same procedure as in the first embodiment.

  As described above, the bottom surface of the reservoir can be formed with a flattened region having a depth of two stages, and a reservoir adjusted to an arbitrary shape and with high formation accuracy can be formed. Further, since the liquid flow path including the nozzle opening is formed on the same substrate, there is no possibility that an adhesion position error occurs when the nozzle plate is adhered as in the conventional example. In this way, it is possible to provide a liquid ejection head that has higher processing accuracy than the prior art and has excellent durability and reliability during ink ejection.

  According to the present invention, not only the plasma etching used in the above embodiments but also other etching methods such as dry etching and wet etching may be used.

It is process drawing explaining the manufacturing method of the liquid discharge head by one Embodiment. It is process drawing explaining the manufacturing method of the liquid discharge head by other embodiment. It is process drawing explaining the manufacturing method of the liquid discharge head by Example 1 which concerns on this invention. It is a figure which shows the mask pattern of the liquid discharge head by Example 1 which concerns on this invention. It is process drawing explaining the manufacturing method of the liquid discharge head by Example 2 which concerns on this invention. It is process drawing explaining the manufacturing method of the liquid discharge head by Example 3 which concerns on this invention. It is a figure which shows the mask pattern of the liquid discharge head by Example 3 which concerns on this invention. It is a schematic cross section which shows the inkjet head of a prior art example. It is process drawing explaining the manufacturing method of the inkjet head of another prior art example.

Explanation of symbols

10, 50, 100, 200, 300, 400 Substrate 11, 56, 101, 201, 301, 401 First etching mask pattern (A surface side)
12, 102, 202, 302, 402 Pressure generation chamber 14, 104, 204, 301 First etching mask pattern (B surface side)
16, 106, 206b, 304, 404 Second etching mask pattern 18, 108, 208, 308, 408 Reservoir 20, 110, 210, 310, 410 Back diaphragm

Claims (8)

  A plurality of pressure generating chambers each having a pressure generating element, a plurality of nozzle ports that respectively communicate with the plurality of pressure generating chambers and discharge liquid, and the plurality of pressure generating chambers via a communicating portion, respectively. A reservoir that is communicated, and the pressure generating chamber and the reservoir each have a recess formed on one main surface and the other main surface of two main surfaces of the same substrate, A liquid discharge head characterized in that a portion shallower than the depth of the communicating portion in the vicinity of the communicating portion in the reservoir is provided in the reservoir.   The liquid ejection head according to claim 1, wherein the communication portion is provided in a region in the vicinity of the communication portion of the reservoir.   The liquid discharge head according to claim 1, wherein the nozzle port is formed in the same substrate as the reservoir.   3. The liquid ejection head according to claim 1, wherein a nozzle plate having the nozzle ports is stacked on the substrate such that the nozzle ports communicate with the pressure generation chamber via a nozzle communication portion. .   The liquid discharge head according to claim 1, wherein the pressure generating element is a piezoelectric actuator or an electrostrictive actuator. A plurality of pressure generating chambers each having a pressure generating element, a plurality of nozzle ports that respectively communicate with the plurality of pressure generating chambers and discharge liquid, and the plurality of pressure generating chambers via a communicating portion, respectively. In a method of manufacturing a liquid ejection head having a reservoir connected to each other,
Forming a recess by etching at least a portion corresponding to the communication portion in one of the two principal surfaces of the substrate;
Forming a recess to be the reservoir by etching a portion corresponding to the reservoir in the one main surface;
Etching the second main surface of the two main surfaces of the substrate to form a recess serving as the pressure generating chamber; and
A method for manufacturing a liquid discharge head, comprising: Etching the portion corresponding to the reservoir to form a recess serving as the reservoir includes sequentially forming a first etching pattern having an opening corresponding to the reservoir on the substrate and the at least the reservoir. Laminating a second etching pattern having an opening corresponding to the communication portion,
The opening corresponding to the at least communication portion is included in the opening corresponding to the reservoir, and after the etching process using the second etching pattern and the separation thereof, the etching process using the first etching pattern is performed. The method of manufacturing a liquid discharge head according to claim 6.   Etching the portion corresponding to the reservoir to form a recess serving as the reservoir includes forming a lattice-like etching pattern in a portion corresponding to the reservoir on the substrate, The opening area corresponding to at least one lattice of the etching pattern formed in the opening corresponding to the communication part is formed in the opening corresponding to the reservoir other than the opening corresponding to the communication part. The method of manufacturing a liquid discharge head according to claim 6, wherein the opening area is larger than a corresponding opening area per lattice of the etching pattern.

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