JP5396367B2 - Inkjet head manufacturing method - Google Patents

Description

  Embodiments described herein relate generally to a method for manufacturing an inkjet head.

  An ink jet head of an ink jet printer includes, for example, a base material formed by bonding two piezoelectric materials and a nozzle plate attached to the base material. The substrate is provided with a plurality of groove-shaped pressure chambers, and electrodes for applying a voltage to the piezoelectric material are formed in the pressure chambers. The volume of the pressure chamber expands or contracts depending on the voltage applied to the substrate through the electrodes. The ink supplied to the pressure chamber is ejected from the nozzles provided in the nozzle plate by being pressurized by the change in volume of the pressure chamber.

  When a current flows through the ink, the quality of the print is degraded due to the change in the quality of the ink. For this reason, a protective film is formed in the pressure chamber, and current is prevented from flowing from the electrode to the ink in the pressure chamber. This protective film is formed in the pressure chamber by vapor deposition polymerization after forming a nozzle on the nozzle plate by laser processing, for example. Furthermore, this protective film is also formed on the inner surface of the nozzle and the outer surface of the nozzle plate.

Japanese Patent Laid-Open No. 2003-266691

  In the ink jet head described above, the portions where the protective film is formed have the same wettability. For this reason, the pressure chamber in which the protective film is formed, the inner surface of the nozzle, and the outer surface of the nozzle plate all have the same wettability, and the ink in the pressure chamber may leak from the nozzle to the outside. If ink leaks from the nozzles, ink ejection during printing becomes unstable.

  An object of the present invention is to provide an ink jet head manufacturing method capable of preventing ink leakage.

An ink jet head manufacturing method according to an embodiment includes:
A base material provided with a pressure chamber, an electrode formed to cover the inner surface of the pressure chamber, and a nozzle that is attached to the base material so as to close the pressure chamber and that opens toward the pressure chamber are provided. And a nozzle plate provided with the ink jet head. First, a protective film for protecting the nozzle plate is attached to the outer surface of the nozzle plate before the nozzle is formed. The nozzle penetrating the protective film and the nozzle plate is formed. Covers the electrode in the pressure chamber, the inner surface of the nozzle plate facing the pressure chamber, the inner surface of the nozzle, and the outer surface of the protective film, and protects the electrode from ink supplied to the pressure chamber. A protective film is formed. The protective film formed on the outer surface of the protective film is removed. By removing the protective film, the outer surface of the nozzle plate having lower wettability than the protective film is exposed.

1 is a perspective view showing a partially cutaway ink jet head according to a first embodiment. FIG. Sectional drawing which shows the nozzle periphery of the inkjet head of 1st Embodiment along the F2-F2 line of FIG. The perspective view which shows the base material before a cover member and a nozzle plate are attached in 1st Embodiment. The perspective view which shows the inkjet head in the middle of the manufacturing process in 1st Embodiment. Sectional drawing which shows the inkjet head in the middle of the manufacturing process in 1st Embodiment along the F5-F5 line | wire of FIG. Sectional drawing which shows the inkjet head in the middle of the manufacturing process in which 1st Embodiment removed some protective films. The perspective view which shows the inkjet head and the manifold which were decomposed | disassembled based on 2nd Embodiment. Sectional drawing which shows the inkjet head and manifold of 2nd Embodiment along the F8-F8 line | wire of FIG. Sectional drawing which expands and shows the nozzle periphery of the inkjet head of 2nd Embodiment. Sectional drawing which shows the inkjet head in the middle of the manufacturing process in 2nd Embodiment. Sectional drawing which shows the inkjet head in the middle of the manufacturing process from which a part of protective film in 2nd Embodiment was removed.

  Hereinafter, a first embodiment of an ink jet head manufacturing method will be described with reference to FIGS. 1 to 6. FIG. 1 is a perspective view showing the inkjet head 10 with a part cut away. FIG. 2 is a cross-sectional view showing the vicinity of the nozzle 29 of the inkjet head 10 along the line F2-F2 in FIG.

  As shown in FIG. 1, the ink jet head 10 is a so-called end shooter type ink jet head, and includes a base material 13, a lid member 14, and a nozzle plate 15. The lid member 14 is attached to the upper surface 13 a of the base material 13. The nozzle plate 15 is attached to the front surface 13 b of the base material 13.

  The base material 13 is formed, for example, by bonding two piezoelectric plates 17 and 18 made of lead zirconate titanate (PZT) so that their polarization directions are opposite to each other. A plurality of pressure chambers 21 are provided in the base material 13.

  The plurality of pressure chambers 21 are each formed in a groove shape, and are provided in parallel with each other in the longitudinal direction of the base material 13. The pressure chambers 21 open to the upper surface 13a and the front surface 13b of the base material 13, respectively. The pressure chamber 21 is closed by the lid member 14 and the nozzle plate 15.

  As shown in FIG. 2, electrodes 22 are respectively formed in the plurality of pressure chambers 21. The electrode 22 is formed of, for example, a nickel thin film, but is not limited thereto, and may be formed of, for example, gold or copper.

  The electrode 22 is formed so as to cover the inner surface of the pressure chamber 21. The electrode 22 covers at least the pair of side surfaces 21a of the pressure chamber 21, and the electrodes on both side surfaces are connected. The pair of side surfaces 21 a is included in the inner surface of the pressure chamber 21. When a voltage is applied to the electrode 22, the base material 13 formed of the piezoelectric material is deformed, and the volume of the pressure chamber 21 is expanded or reduced.

  As shown in FIG. 1, a plurality of wirings 24 are provided on the upper surface 13 a of the base material 13. The plurality of wirings 24 are formed, for example, by laser patterning a nickel thin film formed on the upper surface 13a. The plurality of wirings 24 are respectively provided between the rear end of the upper surface 13 a and the plurality of electrodes 22. One end of the wiring 24 is connected to the electrode 22.

  On the other hand, the other end of the wiring 24 is connected to a printed circuit board of an inkjet printer, for example. The printed circuit board applies a voltage to the electrode 22 through the wiring 24 based on a signal input from the control unit of the ink jet printer, and deforms the base material 13.

  The lid member 14 is attached to the upper surface 13a of the base material 13 by adhesion, for example. An ink supply path 26 is provided in the lid member 14. The ink supply path 26 opens to the plurality of pressure chambers 21 and is connected to the ink tank. The ink in the ink tank is supplied to each pressure chamber 21 via the ink supply path 26.

  The nozzle plate 15 is formed of a rectangular film made of polyimide. The material of the nozzle plate 15 is not limited to this, and any material that can be laser processed may be used. The thickness of the nozzle plate 15 is, for example, 10 to 100 μm. The nozzle plate 15 is attached to the front surface 13b of the substrate 13 by, for example, adhesion. As shown in FIG. 2, the inner surface 15 a of the nozzle plate 15 faces the pressure chamber 21.

  The nozzle plate 15 includes an ink repellent film 27. The ink repellent film 27 is applied to the member main body 28 of the nozzle plate 15 to form the outer surface 15 b of the nozzle plate 15. The ink repellent film 27 is formed of, for example, a fluorine coating agent. The thickness of the ink repellent film is, for example, about 0.1 μm.

  A plurality of nozzles 29 that are holes are provided in the nozzle plate 15. The plurality of nozzles 29 correspond to the plurality of pressure chambers 21 and are arranged side by side in the longitudinal direction of the nozzle plate 15. The plurality of nozzles 29 are open to the plurality of pressure chambers 21.

  As shown in FIG. 2, a protective film 31 is formed to cover the electrode 22 of the pressure chamber 21, the inner surface 15 a of the nozzle plate 15, and a part of the inner surfaces 29 a of the plurality of nozzles 29. The protective film 31 is made of, for example, paraxylene-based polymer. Specifically, paraxylylene-based polymers such as so-called parylene C (polychloroparaxylylene), parylene N (polyparaxylylene), and parylene D (polydichloroparaxylylene) are applied. The protective film 31 is not limited to this, and may be formed of other materials such as polyimide and polyamide.

  The thickness of the protective film 31 is, for example, 1 to 10 μm. The wettability of the protective film 31 is higher than the wettability of the ink repellent film 27 that forms the outer surface 15 b of the nozzle plate 15. The protective film 31 protects the electrode 22 from the ink supplied to the pressure chamber 21 by covering the electrode 22 formed on each of the pair of side surfaces 21 a of the pressure chamber 21.

  Below, an example of the manufacturing method of the inkjet head 10 of the said structure is demonstrated. FIG. 3 is a perspective view showing the base member 13 before the lid member 14 and the nozzle plate 15 are attached. First, for example, a thermosetting adhesive is applied to one piezoelectric plate 17 by, for example, screen printing. However, the present invention is not limited to this, and the adhesive may be applied by other methods such as spin coater, spray coating, and brush coating. The other piezoelectric plate 18 is laminated on the piezoelectric plate 17 coated with an adhesive. For example, the base material 13 is formed by thermosetting the adhesive with an autoclave apparatus. Note that the adhesive may be thermally cured in a later step.

  Next, a plurality of pressure chambers 21 are formed on the base material 13. The plurality of pressure chambers 21 are formed by, for example, cutting the base material 13 with a diamond wheel of a dicing saw used for cutting an IC wafer.

  Next, the electrode 22 is formed on the inner surface of each pressure chamber 21. Further, the wiring 24 is formed on the upper surface 13 a of the base material 13. The electrode 22 and the wiring 24 are formed using, for example, an electroless plating method. Next, patterning is performed by laser irradiation to remove the nickel thin film from portions other than the electrode 22 and the wiring 24.

  FIG. 4 is a perspective view showing the inkjet head 10 during the manufacturing process. FIG. 5 is a cross-sectional view showing the inkjet head 10 during the manufacturing process along the line F5-F5 in FIG. After the electrode 22 and the wiring 24 are formed on the base material 13, the lid member 14 is attached to the upper surface 13 a of the base material 13 using a thermosetting adhesive, and the nozzle 29 is formed on the front surface 13 b of the base material 13. The nozzle plate 15 before mounting is attached. The lid member 14 and the nozzle plate 15 are fixed to the base material 13 by thermosetting the adhesive. At this time, the adhesive applied to the piezoelectric plates 17 and 18 may be thermally cured.

  The nozzle plate 15 is formed by applying an ink repellent film 27 to the member main body 28 using, for example, a bar coater. As shown in FIG. 4, a protective film 32 is pasted on the outer surface 15 b of the nozzle plate 15 in advance.

  The protective film 32 is made of, for example, polyester. The thickness of the protective film 32 is 10-30 micrometers, for example. The protective film 32 covers the entire outer surface 15 b of the nozzle plate 15.

  Next, the nozzle plate 15 is irradiated with excimer laser light to form a plurality of nozzles 29. The plurality of nozzles 29 penetrate the protective film 32 and the nozzle plate 15 and open into the pressure chamber 21. For example, the nozzle plate 15 in which the nozzles 29 are formed in advance may be bonded to the substrate 13.

  Next, the protective film 31 is formed by chemical vapor deposition (CVD). As shown in FIG. 5, the protective film 31 covers the electrode 22 in each pressure chamber 21, the inner surface 15 a of the nozzle plate 15, the inner surface 29 a of each nozzle 29, and the outer surface 32 a of the protective film 32. Is done.

  FIG. 6 is a cross-sectional view showing the inkjet head 10 in the middle of the manufacturing process in which a part of the protective film 31 has been removed. After the protective film 31 is formed, the protective film 31 formed on the outer surface 32a of the protective film 32 is removed by plasma treatment.

  For the plasma treatment, for example, a plasma irradiation apparatus PDC-510 manufactured by Yamato Scientific is used in the RIE mode. As an example of processing conditions, the plasma output is 100 to 200 W, the gas is oxygen, and the oxygen flow rate is 30 cc. Under the above conditions, plasma treatment is performed for 30 to 120 minutes toward the outer surface 32a of the protective film 32. Thereby, the protective film 31 formed on the outer surface 32a of the protective film 32 and a part of the inner surface 29a of the nozzle 29 is removed. At this time, the outer surface 32 a of the protective film 32 is also slightly cut, but the nozzle plate 15 is protected by the protective film 32. Note that a portion that does not require plasma treatment is covered with a jig or masking tape before plasma treatment is performed.

  Next, the protective film 32 is peeled off from the nozzle plate 15 and removed. Thereby, as shown in FIG. 2, the outer surface 15b of the nozzle plate 15 is exposed to the outside. Thus, the manufacturing process of the inkjet head 10 is completed.

  According to the method of manufacturing the inkjet head 10 having the above-described configuration, the electrode 22 in the pressure chamber 21 is covered with the protective film 31, and the outer surface 15 b of the nozzle plate 15 is covered with the ink repellent film 27 having lower wettability than the protective film 31. Is formed. For this reason, a difference arises between the wettability in the pressure chamber 21 and the wettability of the outer surface 15b of the nozzle plate 15. Therefore, it is possible to prevent the ink supplied to the pressure chamber 21 from leaking from the nozzles 29 when printing is stopped, and the ink ejection during printing is stabilized.

  Next, a second embodiment of a method for manufacturing an ink jet head will be described with reference to FIGS. Note that components having the same functions as those of the inkjet head 10 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 7 is a perspective view showing the disassembled inkjet head 40 and manifold 41. FIG. 8 is a cross-sectional view showing the inkjet head 40 and the manifold 41 along the line F8-F8 in FIG.

  As shown in FIG. 7, the ink jet head 40 is a so-called side shooter type ink jet head, and includes a base material 43, a frame member 44, and a nozzle plate 45. The base material 43 includes a base material body 46 and a pair of piezoelectric members 47. As shown in FIG. 8, an ink chamber 49 is formed inside the base material 43, the frame member 44, and the nozzle plate 45. The pair of piezoelectric members 47 are located inside the ink chamber 49.

  The base body 46 is formed in a rectangular plate shape using ceramics such as alumina. The base body 46 has a flat first surface 51 and a second surface 52 located on the opposite side of the first surface 51. The second surface 52 is attached to the manifold 41. The base body 46 is provided with a plurality of supply ports 53, a plurality of first discharge ports 54, and a plurality of second discharge ports 55.

  As shown in FIG. 7, the plurality of supply ports 53 are provided in the central portion of the base body 46. The plurality of supply ports 53 are arranged in the longitudinal direction of the base body 46. The plurality of supply ports 53 are open to the ink chamber 49.

  The supply port 53 is connected to the ink tank via the manifold 41 when the inkjet head 40 is attached to the manifold 41. The ink in the ink tank is supplied from the supply port 53 to the ink chamber 49.

  The plurality of first discharge ports 54 are provided side by side along one side edge 46 a of the base body 46. The plurality of second discharge ports 55 are provided side by side along the other side edge 46 b of the base body 46. A supply port 53 is sandwiched between the first discharge port 54 and the second discharge port 55. The first discharge port 54 and the second discharge port 55 are open to the ink chamber 49.

  The first discharge port 54 and the second discharge port 55 are respectively connected to the ink tank via the manifold 41 when the inkjet head 40 is attached to the manifold 41. The ink in the ink chamber 49 is returned to the ink tank from the first discharge port 54 and the second discharge port 55.

  The frame member 44 is attached to the first surface 51 of the base body 46 with no gap, for example, by adhesion. The frame member 44 surrounds the pair of piezoelectric members 47, the supply port 53, the first discharge port 54, and the second discharge port 55.

  The nozzle plate 45 is formed of a rectangular film made of polyimide. The nozzle plate 45 is attached to the frame member 44 without a gap, for example, by adhesion. The nozzle plate 45 faces the first surface 51 of the base body 46.

  The nozzle plate 45 is provided with a plurality of nozzles 58 that are holes. The plurality of nozzles 58 correspond to the pair of piezoelectric members 47 and are arranged in two rows along the longitudinal direction of the base body 46.

  FIG. 9 is an enlarged cross-sectional view showing the vicinity of the nozzle 58 of the inkjet head 40. As shown in FIG. 9, the nozzle plate 45 includes an ink repellent film 59. The ink repellent film 59 is applied to the member main body 60 of the nozzle plate 45 to form the outer surface 45 b of the nozzle plate 45. The ink repellent film 59 is formed of, for example, a fluorine coating agent, like the ink repellent film 27 of the first embodiment. The thickness of the ink repellent film is, for example, about 0.1 μm.

  As shown in FIG. 7, the pair of piezoelectric members 47 are respectively attached to the first surface 51 of the base body 46 and extend parallel to each other in the longitudinal direction of the base body 46. One piezoelectric member 47 is disposed between the supply port 53 and the first discharge port 54. The other piezoelectric member 47 is disposed between the supply port 53 and the second discharge port 55.

  The pair of piezoelectric members 47 are formed, for example, by bonding two piezoelectric plates made of lead zirconate titanate (PZT) so that their polarization directions are opposite to each other. The pair of piezoelectric members 47 are each formed in a bar shape having a trapezoidal cross section.

  A plurality of pressure chambers 61 are respectively formed in the pair of piezoelectric members 47. The plurality of pressure chambers 61 are grooves that respectively intersect the direction in which the piezoelectric member 47 extends. The plurality of pressure chambers 61 are provided side by side corresponding to the plurality of nozzles 58.

  As shown in FIG. 8, electrodes 62 are respectively formed in the plurality of pressure chambers 61. The electrode 62 is formed on the side surface and the bottom surface of the pressure chamber 61. When a voltage is applied to the electrode 62, the piezoelectric member 47 is deformed and the volume of the pressure chamber 61 is expanded or reduced.

  As shown in FIG. 7, a plurality of wirings 64 are provided on the first surface 51 of the base body 46. The plurality of wirings 64 are formed, for example, by laser patterning a nickel thin film formed on the first surface 51.

  Several wires 64 are provided between one side edge 46 a of the base body 46 and one piezoelectric member 47, and are connected to a plurality of electrodes 62 of the one piezoelectric member 47. The surplus wiring 64 is provided between the other side edge 46 b of the base body 46 and the other piezoelectric member 47, and is connected to the plurality of electrodes 62 of the one piezoelectric member 47.

  An IC for driving the pair of piezoelectric members 47 is connected to the plurality of wirings 64. The IC applies a voltage to the electrode 62 via the wiring 64 based on a signal input from the control unit of the inkjet printer, and deforms the piezoelectric member 47.

  As shown in FIG. 9, a protective film 71 is formed to cover the electrode 62 of the pressure chamber 61, the inner surface 45 a of the nozzle plate 45, and a part of the inner surfaces 58 a of the plurality of nozzles 58. The protective film 71 is formed of, for example, a paraxylylene polymer, similarly to the protective film 31 of the first embodiment.

  The thickness of the protective film 71 is, for example, 1 to 10 μm. The wettability of the protective film 71 is higher than the wettability of the ink repellent film 59 that forms the outer surface 45 b of the nozzle plate 45. The protective film 71 covers the electrodes 62 respectively formed on the inner surface of the pressure chamber 61, thereby protecting the electrodes 62 from the ink supplied to the pressure chamber 61.

  Below, the manufacturing method of the inkjet head 40 of the said structure is demonstrated. First, the supply port 53, the 1st discharge port 54, and the 2nd discharge port 55 are formed in the base-material main body 46 comprised with the ceramic sheet (ceramics green sheet) before baking by press molding. Subsequently, the base body 46 is fired.

  Next, a pair of piezoelectric members 47 are bonded to the base body 46. The pair of piezoelectric members 47 is positioned on the base body 46 via a jig and attached to the base body 46. Subsequently, so-called taper processing is performed on each corner of the pair of piezoelectric members 47. Thereby, each cross section of the pair of piezoelectric members 47 becomes trapezoidal.

  Next, a plurality of pressure chambers 61 are formed in the pair of piezoelectric members 47. The plurality of pressure chambers 61 are formed by, for example, a diamond wheel of a dicing saw used for cutting an IC wafer.

  Next, the electrode 62 is formed on the inner surface of each of the plurality of pressure chambers 61. Further, a plurality of wirings 64 are formed on the first surface 51 of the base body 46. The electrode 62 and the wiring 64 are formed by, for example, a nickel thin film using an electroless plating method. Next, patterning is performed by laser irradiation to remove the nickel thin film from portions other than the electrode 62 and the wiring 64.

  FIG. 10 is a cross-sectional view showing the inkjet head 40 during the manufacturing process. After forming the electrode 62 and the wiring 64, the frame member 44 is bonded to the base body 46. The nozzle plate 45 is bonded to the frame member 44 attached to the base body 46.

  The nozzle plate 45 is formed by applying an ink repellent film 59 to the member main body 60 using, for example, a bar coater. As shown in FIG. 10, a protective film 73 is attached in advance to the outer surface 45 b of the nozzle plate 45.

  The protective film 73 is made of polyester, for example. The thickness of the protective film 73 is, for example, 10 to 30 μm. The protective film 73 covers the entire outer surface 45 b of the nozzle plate 45.

  Next, the nozzle plate 45 is irradiated with laser light to form a plurality of nozzles 58. The plurality of nozzles 58 pass through the protective film 73 and the nozzle plate 45 and open toward the pressure chamber 61 in the ink chamber 49. For example, the nozzle plate 45 in which the nozzles 58 are formed in advance may be bonded to the base material 43.

  Next, the protective film 71 is formed by CVD. As shown in FIG. 10, the protective film 71 includes electrodes 62 in each pressure chamber 61, an inner surface 45 a of the nozzle plate 45 that forms the ink chamber 49, a first surface 51 of the base body 46, and each nozzle 58. The inner surface 58a of the protective film 73 and the outer surface 73a of the protective film 73 are deposited.

  FIG. 11 is a cross-sectional view showing the inkjet head 40 in the middle of the manufacturing process from which part of the protective film 71 has been removed. After the protective film 71 is formed, plasma processing is performed on the protective film 71 as in the first embodiment.

  By the plasma treatment, the protective film 71 formed on the outer surface 73a of the protective film 73 and a part of the inner surface 58a of the nozzle 58 is removed. At this time, the outer surface 73 a of the protective film 73 is also slightly cut, but the nozzle plate 45 is protected by the protective film 73.

  Next, the protective film 73 is peeled off from the nozzle plate 45 and removed. Thereby, as shown in FIG. 9, the outer surface 45b of the nozzle plate 45 is exposed to the outside. Next, the IC is fixed to the first surface 51 of the base body 46 and connected to the wiring 64. Thus, the manufacturing process of the inkjet head 40 is completed.

  As described above, even when the inkjet head 40 of a method different from that of the inkjet head 10 of the first embodiment is manufactured, the same effect as that of the first embodiment can be obtained.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10, 40 ... Inkjet head, 13, 43 ... Base material, 15, 45 ... Nozzle plate, 15a, 45a ... Inner surface of nozzle plate, 15b, 45b ... Outer surface of nozzle plate, 21, 61 ... Pressure chamber, 22, 62 ... Electrodes, 27, 59 ... ink repellent film, 29, 58 ... nozzle, 29a, 58a ... inner surface of nozzle, 31, 71 ... protective film, 32, 73 ... protective film, 32a, 73a ... outer surface of protective film.

Claims (4)

A base material provided with a pressure chamber, an electrode formed to cover the inner surface of the pressure chamber, and a nozzle that is attached to the base material so as to close the pressure chamber and that opens toward the pressure chamber are provided. A nozzle plate, and an inkjet head manufacturing method comprising:
Affixing a protective film for protecting the nozzle plate on the outer surface of the nozzle plate before the nozzle is formed,
Forming the nozzle penetrating the protective film and the nozzle plate;
Covers the electrode in the pressure chamber, the inner surface of the nozzle plate facing the pressure chamber, the inner surface of the nozzle, and the outer surface of the protective film, and protects the electrode from ink supplied to the pressure chamber. Forming a protective film,
Removing the protective film formed on the outer surface of the protective film;
A method for manufacturing an ink jet head, comprising: removing the protective film to expose an outer surface of the nozzle plate having lower wettability than the protective film.   The method of manufacturing an ink jet head according to claim 1, wherein the nozzle plate includes an ink repellent film that forms an outer surface of the nozzle plate.   The inkjet head according to claim 2, wherein when removing the protective film formed on the outer surface of the protective film, the protective film formed on at least a part of the inner surface of the nozzle is further removed. Production method.   The method of manufacturing an ink jet head according to claim 3, wherein the protective film is removed by plasma treatment.

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