JP2008143088A - Nozzle plate manufacturing method, liquid discharge head, and image forming apparatus - Google Patents

Abstract

To accurately form a constricted nozzle.
SOLUTION: (A) A step of forming a photosensitive layer 241 made of a resist on a porous substrate 22, and (B) and (C) an R-shaped opening 51b made of a non-translucent material on the photosensitive layer 241. A porous substrate while exposing light from an oblique direction to the surface of the photosensitive layer 241 on which the R-shaped opening layer 32 is formed; 22 is rotated to expose the photosensitive layer 241 using the R-shaped opening layer 32 as an exposure mask, thereby forming a tapered photosensitive portion 25a in the photosensitive layer 241 and developing the tapered photosensitive portion 25a. Removing the non-photosensitive portion, leaving the tapered photosensitive portion 25a as a mold, forming a tapered opening layer having a tapered opening connected to the R-shaped opening 51b, and a tapered photosensitive portion 25a And a step of removing the porous substrate 22.
[Selection] FIG.

Description

  The present invention relates to a method for manufacturing a nozzle plate, and more particularly to a method for manufacturing a nozzle plate used in a liquid discharge head typified by an inkjet head, a liquid discharge head including the nozzle plate manufactured thereby, and an image forming apparatus.

  Since the ink jet recording apparatus is a method of forming an image on a recording medium by discharging ink from fine nozzles (liquid discharge ports) of a liquid discharge head, the nozzle plate on which the nozzles are formed has an ink discharge performance. It is one of the very important parts to decide. The ink ejection performance varies greatly depending on the nozzle shape and the like, and high dimensional accuracy is required to make the ejection performance uniform for many nozzles.

  In particular, in recent years, in the field of ink jet recording, the need for high-speed and high image quality has further increased, and a one-pass recording (recording by one sub-scan feed using a page-wide liquid discharge head) system using high-viscosity ink has been developed. However, the nozzle part of the liquid discharge head is required to have a thin and wide angle to reduce the flow resistance, and to achieve high accuracy and page wide wide recording to reduce image density unevenness. There are demands for higher nozzle reliability and higher reliability for stable operation.

  Regarding the nozzle plate manufacturing technique, Patent Document 1 discloses a technique for forming a metal taper nozzle with a counterbore having a high aspect ratio by performing double-sided exposure from the front and back sides of a substrate. In addition to an example of performing exposure with diffused light using a diffusion plate, an example of performing exposure by tilting and rotating a substrate is described in the formation of the tapered opening.

  Patent Document 2 discloses a technique for improving the wiping performance and the jetting stability by forming the nozzle lyophobic portion into a round shape with an opening increasing toward the surface. The liquid repellent material is applied by a dispenser.

Patent Document 3 discloses a technique for forming a so-called “necked” nozzle to improve landing errors. As an example of the “constriction” shape, a forward tapered shape portion that narrows from the liquid inflow side to the liquid discharge side in the thickness direction of the nozzle plate, and a liquid that is connected to the forward tapered shape portion in the thickness direction of the nozzle plate. There is described what is constituted by an inversely tapered portion widened from the inflow side toward the liquid discharge side.
JP 7-329304 A JP 2006-51808 A JP 2001-187451 A

  When the nozzle is linear, there is a problem that the meniscus position is not stable. In addition, if the corner formed with the liquid discharge surface of the nozzle is sharp, there is a problem that it is easily damaged due to sliding of the wiping member and jamming of the recording paper. Moreover, it is preferable that the liquid inflow side of a nozzle is the shape opened at the wide angle toward the liquid inflow side from the viewpoint of the refill property of the liquid to a nozzle. Therefore, the liquid inflow side of the nozzle has a forward taper shape (a shape that narrows from the liquid inflow side toward the liquid discharge side in the thickness direction of the nozzle plate), and the liquid discharge side has a reverse taper shape (liquid in the thickness direction of the nozzle plate). There is a need for a so-called “necked” nozzle having a shape that widens from the inflow side toward the liquid discharge side.

  However, it is difficult to form a “necked” wide-angle nozzle in a batch with high accuracy.

  In the invention disclosed in Patent Document 1, since double-sided exposure is performed from the front and back of the substrate, not only handling during processing is easy, but also an axis misalignment between the front and back sides of the substrate tends to occur. In addition, with exposure using diffused light, shape control is difficult and shape variations are likely to occur.

  Since the invention disclosed in Patent Document 2 is a method in which a liquid repellent material is applied by a dispenser to form a curved surface shape naturally, shape variation tends to occur.

  The invention disclosed in Patent Document 3 forms a taper of about 12 ° by exposure with a relatively large NA (numerical aperture) using a Keller illumination system, but there is a limit to increasing NA. For example, it is difficult to form a wide-angle taper of 20 to 40 °, which is expected to be necessary for high-speed discharge of a high-viscosity liquid having a viscosity of 10 to 20 mPa · s at a high discharge frequency of 20 to 40 kHz.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method of manufacturing a nozzle plate capable of forming a wide-angle nozzle having a constriction shape with a stable meniscus position with high accuracy. An object of the present invention is to provide a liquid discharge head using a nozzle plate manufactured by such a manufacturing method, and an image forming apparatus using the same.

  In order to achieve the above object, the invention described in claim 1 includes a step of forming a photosensitive layer made of a photosensitive material on one surface of a predetermined substrate, and transmitting light for exposure on the photosensitive layer. A curved opening layer forming step of forming a curved opening layer having a curved opening with a curved periphery, and a side of the photosensitive layer on which the curved opening layer is formed The photosensitive layer is exposed to light by exposing the photosensitive layer by using the curved opening layer as an exposure mask by rotating the substrate while exposing light for exposure from an oblique direction to the surface of the substrate. An exposure step for forming a shape-sensitive portion; a developing step for developing the photosensitive layer to remove the non-photosensitive portion while leaving the tapered photosensitive portion in the photosensitive layer; and the tapered photosensitive portion as a mold Connected to the curved opening. A nozzle plate manufacturing method comprising: a tapered opening layer forming step of forming a tapered opening layer having a tapered opening portion; and a removing step of removing the tapered photosensitive portion and the substrate. To do.

  The nozzle plate obtained by such a manufacturing method is arranged such that when the tapered opening layer is arranged on the liquid inflow side and the curved opening layer is arranged on the liquid discharge side, the liquid inflow side in the thickness direction of the nozzle plate A tapered opening that narrows from the liquid discharge side to the liquid discharge side, and a curved opening that connects to the taper shape opening and widens from the liquid inflow side to the liquid discharge side in the thickness direction of the nozzle plate. A “necked” shaped nozzle is constructed.

  On the other hand, a curved surface that narrows from the liquid inflow side to the liquid discharge side in the thickness direction of the nozzle plate by disposing the curved opening layer on the liquid inflow side and the tapered opening layer on the liquid discharge side. A constricted-shaped nozzle is configured by a tapered opening and a tapered opening that is connected to the curved curved opening and widens from the liquid inflow side toward the liquid discharge side in the thickness direction of the nozzle plate. Also good.

  According to the present invention, exposure using a curved opening layer as an exposure mask and rotating the substrate while exposing light from an oblique direction to the surface of the photosensitive layer on which the curved opening layer is formed (so-called exposure) Since a tapered photosensitive portion is formed as a die of a tapered opening by performing inclined rotation exposure, and a tapered opening connected to a curved opening is formed using the tapered photosensitive portion as a die. Compared with the case of using the conventional technology that exposes from both front and back surfaces, or when the curved opening layer is formed as a separate piece, the axis of the curved opening and the axis of the tapered opening can be prevented from shifting. In addition, it is easy to handle during processing. In this way, an axially symmetric `` necked '' shaped nozzle can be formed with good handling during processing, so that not only the meniscus position is stabilized but also the flying bend is eliminated, so there is less landing position variation, and wiping resistance is good. A quality nozzle plate can be easily provided.

  According to a second aspect of the present invention, in the first aspect of the invention, the curved opening layer forming step is a patterning for forming a first conductive film having an opening pattern on the non-conductive photosensitive layer. A step of electroforming using the first conductive film as an electrode, covering the first conductive film and overhanging from an opening edge of the first conductive film; An overhang electroforming process for forming a film is provided, and a method for manufacturing a nozzle plate is provided.

  According to the present invention, electroforming is performed using the first conductive film having an opening pattern as an electrode, and the second conductive film (overhanging metal) overhangs from the opening edge of the first conductive film toward the inner wall thereof. Therefore, a high-definition R shape (curved surface) having a high curvature according to the thickness of the second conductive film can be easily formed in a lump. That is, it is possible to easily provide a nozzle plate having a high-definition “necked” shape nozzle suitable for increasing the density of nozzle arrangements such as a two-dimensional matrix using a metal material having relatively high rigidity. For example, as compared with the case where laser drilling is performed on a plate-shaped member made of polyimide, it can be formed in a lump with high rigidity and high accuracy.

  The invention according to claim 3 is the invention according to claim 2, wherein the overhang electroforming step uses an electroforming liquid containing a metal material and a liquid repellent material, and the liquid repellent material in the electroforming liquid is used. And a metal material are co-deposited as the second conductive film.

  According to the present invention, by using an electroforming liquid containing a metal material and a liquid repellent material, the liquid repellent material is co-deposited together with the metal material as the second conductive film, whereby the liquid repellent portion ( Since the boundary between the curved opening) and the non-liquid-repellent portion (tapered opening) on the liquid inflow side coincides with the constricted position, the meniscus position is further stabilized and the discharge stability is further improved. become. Further, since the ejection surface has liquid repellency, ink adhesion and wiping properties are also improved.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the substrate is made of a porous material, and the step of forming the tapered opening layer includes the opening layer with a curved surface. A method for producing a nozzle plate is provided, which is performed by electroforming using as an electrode.

  According to the present invention, since the electroforming liquid and the current can be flowed quickly through the substrate having the porous member, the taper shape while sufficiently supplying the electroforming liquid between the substrate and the curved opening layer. The opening layer can be grown homogeneously and rapidly.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein a part of the photosensitive layer is exposed before the step of forming the curved opening layer. By exposing the photosensitive layer until it penetrates in the thickness direction, a support material is formed that is positioned around the tapered photosensitive portion to be formed and interposed between the substrate and the curved opening layer. There is further provided a method for producing a nozzle plate, further comprising a supporting material forming step.

  According to the present invention, the support member interposed as a bridge between the substrate and the curved opening layer can be easily formed, and the tapered opening layer can be stably electroformed. Moreover, a groove part can also be easily formed in the liquid inflow surface of a nozzle plate using a support material as a type | mold. The groove portion of the liquid inflow surface formed in this way has a function to relieve thermal stress caused by temperature change when the nozzle plate is bonded to another flow path structure or temperature change during operation, The effect of further improvement in reliability can be expected.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the opening with curved surface is after the curved opening layer forming step and before the developing step. By adhering the photosensitive material to the surface of the layer opposite to the side on which the photosensitive layer is formed, and using the photosensitive material as a mold without removing a part of the photosensitive material in the development step, Provided is a method for manufacturing a nozzle plate, wherein at least one of a concave counterbore portion connected to an opening portion with a curved surface and a concave groove portion positioned around the opening portion with a curved surface is formed. .

  According to this invention, the tapered opening layer is stably formed by improving the rigidity of the nozzle portion of the curved opening layer by the photosensitive material adhered to both surfaces of the curved opening layer, and the liquid ejection surface. At least one of the counterbore part and the groove part is formed. The counterbore portion connected to the opening with the curved surface has a function of protecting the nozzle when wiping the liquid discharge surface or jamming of the discharge medium, and can be expected to improve the reliability of liquid discharge. Moreover, the groove part located around the opening part with a curved surface has a function of trapping excess ink on the liquid discharge surface, and an effect of reducing ink contamination on the liquid discharge surface can be expected. Further, the groove portion of the liquid discharge surface may be disposed along, for example, the wiping direction of the liquid discharge surface, and the groove portion of the liquid discharge surface may have a function of improving the wiping property.

  According to a seventh aspect of the present invention, there is provided an exposure mask having an optical interference film having a characteristic in which a transmittance of the exposure light changes according to an incident angle of the exposure light, or the optical interference film, Preparing an exposure mask comprising a light blocking film that does not transmit light for exposure or an exposure mask having the light blocking film, and forming a photosensitive layer made of a photosensitive material on one surface of a predetermined substrate; And a curved opening layer forming step for forming a curved opening layer having a curved opening with a curved periphery formed of a non-translucent material that does not transmit the exposure light on the photosensitive layer; The exposure light is incident substantially perpendicularly to the surface of the photosensitive layer on which the curved opening layer is formed, and the photosensitive layer is exposed using at least the curved opening layer. An exposure step, and opening of the photosensitive layer with the curved surface. A second exposure that exposes the photosensitive layer using the curved opening layer and the exposure mask by rotating the substrate while exposing light from an oblique direction to the surface on which the layer is formed; A developing step of developing the photosensitive layer to remove a non-photosensitive portion of the photosensitive layer, and a straight-shaped opening connected to the curved opening using the photosensitive portion of the photosensitive layer as a mold A taper-shaped opening layer forming step of forming a taper-shaped opening layer having a taper-shaped opening connected to the straight-shaped opening, and a removing step of removing the photosensitive portion of the photosensitive layer and the substrate. A nozzle plate manufacturing method is provided.

  According to the present invention, since the straight opening is formed between the curved opening and the tapered opening, a smoother “necked” shape is formed.

  According to an eighth aspect of the present invention, there is provided a liquid discharge head comprising a nozzle plate manufactured by the nozzle plate manufacturing method according to any one of the first to seventh aspects.

  According to a ninth aspect of the present invention, there is provided an image forming apparatus comprising the liquid discharge head according to the eighth aspect.

  An ink jet recording apparatus as an aspect of the image forming apparatus according to claim 9 is a liquid including a nozzle for discharging ink droplets for forming dots and a pressure generating element (piezoelectric actuator) for generating discharge pressure. A discharge control means that includes a liquid discharge head in which a large number of discharge elements are arranged at high density and controls discharge of liquid droplets from the liquid discharge head based on ink discharge data (dot image data) generated from an input image And an image is formed on the recording medium by droplets ejected from the nozzle.

  For example, color conversion and halftoning processing are performed based on image data (print data) input via the image input means, and ink ejection data corresponding to the ink color is generated. Based on this ink ejection data, the drive of the pressure generating element corresponding to each nozzle of the liquid ejection head is controlled, and an ink droplet is ejected from the nozzle.

  In order to realize high-resolution image output, a droplet discharge element (ink chamber unit) including a nozzle (discharge port) for discharging an ink liquid, a pressure chamber corresponding to the nozzle, and a pressure generation element ) Is preferably used in a liquid discharge head in which a large number of nozzles are arranged at high density.

  As a configuration example of such a liquid discharge head for printing, a full line type head having a nozzle row in which a plurality of discharge ports (nozzles) are arranged over a length corresponding to the entire width of the recording medium can be used. In this case, a combination of a plurality of relatively short ejection head modules having a nozzle row less than the length corresponding to the entire width of the recording medium, and connecting them together, the nozzle having a length corresponding to the entire width of the recording medium as a whole There is an aspect that constitutes a column.

  A full-line type head is usually arranged along a direction perpendicular to the relative feeding direction (relative conveyance direction) of the recording medium, but has a certain angle with respect to the direction perpendicular to the conveyance direction. There may be a mode in which the head is arranged along the oblique direction.

  “Recording medium” is a medium (which can be referred to as a printing medium, an image forming medium, a recording medium, an image receiving medium, a discharged medium, or the like) that receives adhesion of ink discharged from the discharge port of the liquid discharge head. Various media are included regardless of material or shape, such as continuous paper, cut paper, sealing paper, resin sheets such as OHP sheets, printed boards on which films, cloths, wiring patterns, etc. are formed.

  The transporting means for moving the recording medium and the liquid discharge head relative to each other includes a mode for transporting the recording medium to the stopped (fixed) head, a mode for moving the head relative to the stopped recording medium, or a head And a mode in which both the recording medium and the recording medium are moved. When a color image is formed using an inkjet print head, a print head may be arranged for each of a plurality of colors of ink (recording liquid), or a plurality of colors of ink are ejected from one print head. It is good also as a possible structure.

  According to the present invention, a “necked” wide-angle nozzle with a stable meniscus position can be collectively formed with high accuracy.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Exposure equipment]
First, an outline of a configuration example of an inclined rotation type exposure apparatus used in a nozzle plate manufacturing method according to an embodiment of the present invention will be described.

  FIG. 1 is a block diagram showing an example of an exposure apparatus. The exposure apparatus 10 is mainly composed of a light source 12, an irradiation optical system 14, an immersion container 16, a transmission correction plate 18, and a stage 20, and the light emitted from the light source 12 is paralleled downward in the figure by the irradiation optical system 14. The resist 24 is exposed to light by irradiating the resist (photosensitive material) 24 on the stage 20 that is inclined and rotated through the exposure mask 40. The resist 24 is attached to the porous substrate 22 on the stage 20.

  The stage 20 is disposed in the immersion container 16. The stage 20 introduces a liquid (for example, pure water) into the immersion container 16 to perform exposure in the liquid, and performs exposure in the gas. It is possible to switch between normal (dry) exposure.

  In addition, the stage 20 includes a rotation mechanism that can rotate the table surface 20a in-plane, and a tilt mechanism that can adjust the tilt angle of the table surface 20a (the tilt angle with respect to the horizontal plane, that is, the incident angle of irradiation light). It is a tilting and rotating stage.

  That is, the stage 20 is attached to a rotary shaft 21 (first rotary shaft) perpendicular to the table surface 20a, and is rotatable about the rotary shaft 21. Further, the rotating shaft 21 of the stage 20 is a mechanism that can swing in a vertical plane orthogonal to the table surface 20a, and the inclination angle of the table surface 20a can be varied depending on the swinging position of the rotating shaft 21 of the stage 20. . Further, the rotation shaft 21 of the stage 20, the stage 20, and the entire liquid immersion container 16 are rotatable around a vertical axis A (second rotation axis) in a horizontal plane parallel to the vertical axis A. The specific structure of the mechanism for tilting and rotating the stage 20 will be described later.

  FIG. 2A is an enlarged view of a main part showing an example of the exposure mask 40 of FIG. In FIG. 2A, a part 32 (R-shaped opening layer) of the nozzle plate to be formed is formed on the resist 24 as the exposure mask 40 in FIG. The resist 24 is irradiated with light for exposure. A part of nozzle plate 51b (R-shaped opening) is formed in the part 32 of the nozzle plate, which is the exposure mask 40, and the resist 24 is exposed to light that has passed through part of the nozzle 51b.

  FIG. 2B shows an example in which a light blocking film 41 and a light interference film 42 are used as the exposure mask 40 in FIG.

  The light blocking film 41 has a non-light-transmitting property that does not transmit exposure light, and has an opening 410 for exposing the resist 24. The light blocking film 41 is made of, for example, chromium (Cr) or chromium oxide, and is formed by a method such as sputtering or vacuum deposition.

  The optical interference film 42 has an incident angle dependency in which the light transmittance changes depending on the incident angle of light, and has an opening 420 for exposing the resist 24. The optical interference film 42 is composed of a dielectric multilayer film in which a high refractive index material and a low refractive index material are alternately laminated. By adjusting the film thicknesses of the high refractive index material and the low refractive index material, a predetermined wavelength is obtained. In contrast, a desired light transmittance can be obtained. In addition, the photosensitive region of the resist 24 is controlled using the incident angle dependency of the light transmittance of the optical interference film 42.

  The exposure mask 40 is not particularly limited to the case where both the light blocking film 41 and the light interference film 42 are used as the exposure mask 40 as shown in FIG. 2B, and only the light blocking film 41 is exposed to the exposure mask 40. It may be used as In addition, a part of the nozzle plate (32 in FIG. 2A) to be formed may be used as an exposure mask together with the optical interference film.

  A recess 44 is formed in the table surface 20a of the stage 20 so that a gap 43 is formed on the back side of the resist 24 (photosensitive layer) with the porous substrate 22, the resist 24 and the exposure mask 40 fixed on the stage 20. Is formed. During dry exposure, the gap 43 is filled with a gas to form a gas layer. On the other hand, at the time of immersion exposure, the gap 43 is filled with a liquid to form a liquid layer. An antireflection film 46 is formed in the recess 44.

  2A and 2B, a light receiving sensor 48 capable of receiving exposure light is embedded in the stage 20, and the light for exposure is monitored by the light receiving sensor 48. The exposure amount (that is, the light irradiation time or the irradiation intensity, or a combination thereof) is controlled. Although the case where the light receiving sensor 48 directly receives the exposure light is shown as an example, preferably, the light receiving sensor 48 receives the light transmitted through the resist 24 and the light transmitted through the resist 24 by the light receiving sensor 48. The exposure amount may be controlled while monitoring.

  FIG. 3 is a plan perspective view showing an arrangement example of the light receiving sensors 48 embedded in the stage 20. FIG. 3 shows an example in which four nozzle plate forming portions 50 are provided on the stage 20 (specifically, on the porous substrate 22 of FIG. 1).

  In addition, about the shape of the nozzle plate formation part 50 or the light reception sensor 48, the number of arrangement | positioning, and an arrangement position, various forms are possible and it is not limited to the example of FIG.

  FIG. 4 is a block diagram of the light source 12 and the irradiation optical system 14 used in the exposure apparatus 10 shown in FIG. As shown in FIG. 4, the illumination unit 60 used in the exposure apparatus 10 of this example uses an ultrahigh pressure mercury lamp 61 as a light source. The light emitted from the ultra-high pressure mercury lamp 61 is collected by the elliptical condenser mirror 62, the optical path is bent in the horizontal direction by the plane reflecting mirror 63, and then enters the integrator lens 64.

  The light whose illuminance distribution has been made uniform by the integrator lens 64 is selected by the light source filter 65 and then the light path is bent by the planar reflection mirror 66 in the vertical direction and enters the collimator lens 67. The light converted into parallel light by the collimator lens 67 is irradiated toward the irradiation surface 68 as parallel irradiation light having a uniform illuminance distribution.

  In this example, of the light source spectrum of the ultrahigh pressure mercury lamp 61 shown in FIG. 5, the i-line (wavelength = 365 nm) and the wavelength region in the vicinity thereof are used, and the optical filter 65 described in FIG. In the light source spectrum of the ultra-high pressure mercury lamp 61, a filter that cuts light on the shorter wavelength side than the i-line, such as j-line (313 nm) and 334 nm, is used.

  The type and wavelength of the light source to be used are not limited to the above example, and an appropriate light source (wavelength) is selected in relation to the photosensitive characteristics of the photoresist to be used. In carrying out the present invention, a mode in which a solid-state laser, a semiconductor laser (for example, wavelengths: 355 nm, 375 nm, 405 nm) or the like is used as a light source for illumination is also possible.

  FIG. 6 is a graph showing an example of spectral characteristics of transmittance in the optical interference film 42 used in the exposure mask 40 of this example. The horizontal axis indicates the wavelength, the vertical axis indicates the transmittance, and the characteristics when the incident angle of light is 0 degrees, 15 degrees, 30 degrees, and 45 degrees are shown. As shown in FIG. 6, the transmission wavelength band has a characteristic of shifting to the short wavelength side as the incident angle of light increases (when light is irradiated obliquely).

  As described above, in this embodiment, the i-line (wavelength = 365 nm) of the ultrahigh pressure mercury lamp 61 is mainly used as the light source for exposure (see FIGS. 4 and 5). In FIG. 6, when paying attention to the wavelength 365 nm (i-line), when the incident angle is 35 degrees or more, the transmittance is approximately 0%, and the transmittance gradually increases as the incident angle decreases, and the incident angle is 0 degrees. In the case of (normal incidence), the transmittance is maximum (in this example, about 30%). Exposure is performed while changing the incident angle by utilizing such a characteristic that the light transmittance changes according to the magnitude of the incident angle.

  Next, the configuration of the means for changing the incident angle will be described.

  FIG. 7 is a block diagram of the stage tilt rotation mechanism and its surroundings in the exposure apparatus 10 of this example. Although the case of immersion exposure in which the liquid is filled in the liquid immersion container 16 is illustrated as an example, expectation is satisfied in the liquid immersion container 16 at the time of dry exposure.

  The rotating shaft 21 of the stage 20 is attached in a state of penetrating the bottom surface of the immersion container 16, and a liquid (for example, pure water 70) in the immersion container 16 is attached to a connection portion that penetrates the immersion container 16. Waterproofing is applied so as not to leak from this portion, and a spherical bearing 72 is provided so that the rotating shaft 21 can be rotated and the tilt angle can be adjusted (oscillated).

  That is, the rotary shaft 21 of the stage 20 is supported in a state of penetrating the liquid immersion container 16 via a spherical bearing 72 attached to the bottom surface of the liquid immersion container 16, and the lower end of the rotary shaft 21 has a free joint 74. And an output shaft 78 of a motor 76 (referred to as “stage rotation motor”). This stage rotation motor 76 is fixed to a slider 82 that slides along a linear motion guide 80, and the stage rotational motor 76 is linearly guided along with the slider 82 by driving a motor (referred to as an “inclination swing motor”) 84. 80 can be moved.

  By moving the stage rotation motor 76 on the slider 82 in the left-right direction in FIG. 7 by driving the tilt swing motor 84, the rotary shaft 21 of the stage 20 can be swung around the fixed point 86 in the spherical bearing 72. The tilt angle of the rotating shaft 21 (that is, the tilt angle of the table surface) can be adjusted by the swing position. Thereby, the incident angle of the light with respect to the exposure mask 40 can be changed.

  Further, when the output shaft 78 is rotated by driving the stage rotation motor 76, the rotational force is transmitted to the rotation shaft 21 via the universal joint 74, and the stage 20 is rotated.

  A liquid pump 88 is provided in the liquid immersion container 16 in which the stage 20 is accommodated, and the liquid pump 88 can supply and discharge liquid for immersion (here, pure water 70).

  During immersion exposure, pure water 70 is introduced into the immersion vessel 16 via the liquid pump 88, and the immersion vessel 16 is filled with the pure water 70. In normal exposure (during dry exposure), pure water 70 is discharged from the immersion vessel 16 and the inside of the immersion vessel 16 is replaced with gas (for example, air).

  In addition to the pure water 70, the immersion liquid includes a dedicated immersion liquid prepared for use in an exposure apparatus. In some cases, such an exclusive liquid is used. It is also possible.

  When performing immersion exposure, exposure light is absorbed by the liquid covering the periphery of the exposure mask. When light is incident perpendicularly to the liquid surface and light is irradiated substantially perpendicularly to the exposure mask 40 (in the case of vertical exposure or narrow-angle incident exposure), the light traveling in the liquid reaches the exposure mask 40. Since the distance (optical path length) until completion is substantially constant at each position of the exposure mask 40, the absorption of exposure light by the liquid can be considered to be uniform (substantially uniform) at each position on the exposure mask 40. The only problem is that it is attenuated (including substantially uniform having a range distribution).

  However, in the case of performing oblique exposure with the light incident on the liquid surface and an oblique exposure with a relatively large incident angle with respect to the exposure mask 40, the exposure light is incident perpendicular to the liquid surface. The distance (optical path length) of the traveling light to reach the exposure mask 40 varies depending on the location at each position of the exposure mask 40. A light amount distribution is generated on the exposure mask 40 due to the difference in the light absorption amount due to the difference in the optical path length, thereby making the exposure of the resist 24 non-uniform.

  Specifically, in the region where the distance (optical path length) until the exposure light enters the liquid and reaches the surface of the exposure mask 40 is short, the attenuation of the exposure light is small, and therefore reaches the surface of the exposure mask 40. Although the amount of exposure light is relatively large, the photoresist coated on the back surface of the exposure mask 40 can be sufficiently exposed, but the distance (optical path) until the exposure light reaches the surface of the exposure mask 40 after entering the liquid. In the long region, the attenuation of the exposure light is large. Therefore, the amount of the exposure light reaching the surface of the exposure mask 40 is less than when the optical path length is short, and the photoresist cannot be sufficiently exposed in the same exposure time. . On the other hand, if exposure is performed with an exposure time sufficient to perform exposure in a region with a long optical path length, overexposure occurs in a region with a short optical path length, and the photoresist is not exposed in the same state as the region with a long optical path length. For this reason, the photosensitivity of the photoresist becomes non-uniform.

  For this reason, in this embodiment, the transmission correction plate 18 for correcting the transmittance distribution is used so that a uniform light amount distribution can be obtained on the exposure mask 40 during the tilt exposure in the liquid. The transmission correction plate 18 is a transmittance gradient substrate having a transmittance distribution corresponding to the distance (optical path length) until the light incident on the liquid reaches the exposure mask 40, and after being incident on the liquid, the exposure mask. The transmittance is high in the region where the distance (optical path length) to reach 40 is long, and the transmittance is low in the region where the distance (optical path length) until it reaches the exposure mask 40 after entering the liquid is short. It is configured.

  The transmission correction plate 18 is attached to the upper part of the immersion container 16 via an opening / closing hinge 90, and the transmission correction plate 18 seals the top surface of the immersion container 16 by the opening / closing hinge 90 and the top surface. It is possible to move to a position outside the exposure area retracted from.

  In the present embodiment, during vertical exposure or tilt exposure with a relatively small incident angle (referred to as a “narrow angle tilt rotation exposure process”), the transmission correction plate 18 is moved out of the exposure area and incident. In the case of tilt exposure with a relatively large angle (referred to as “wide-angle tilt rotation exposure process”), the transmission correction plate 18 is moved to the upper part (position for sealing the top surface) on the immersion container 16 in the exposure area. Let

  Strictly speaking, an illuminance distribution is generated at the time of vertical exposure or a narrow-angle tilt rotation exposure process, but the narrow-angle taper has little influence and has no practical problem. Including the narrow-angle tilt exposure process, several types of appropriate transmission correction plates are prepared corresponding to the incident angle of light during tilted exposure, depending on the incident angle of light during tilted exposure. Thus, a mode in which the transmission correction plate is switched and used is also possible.

  By using the transmission correction plate 18 as described above, when the exposure light incident from the illumination unit 60 reaches the exposure mask 40 via the transmission correction plate 18 and the pure water 70 as the immersion liquid, the exposure mask is used. On 40, the amount of exposure light is uniform over the entire surface. In this way, illuminance change according to the optical axis distance during tilt rotation and illuminance distribution in the plane can be corrected, so even when producing a relatively large size (long) nozzle plate, there is little variation and stable. Nozzle formation is possible.

  Further, by arranging the transmission correction plate 18 so as to be in contact with the surface of the pure water 70 which is an immersion liquid, that is, a boundary surface in contact with air, and performing exposure in a state where the liquid is filled, the liquid ripples and bubbles It is possible to prevent harmful effects peculiar to immersion exposure, such as entrainment of liquid.

  As another method for equalizing the amount of light on the exposure mask 40 during immersion tilt exposure, a method in which the exposure mask 40 and the liquid surface of the liquid used for immersion are parallel may be considered. Keeping the exposure mask 40 in a parallel state always requires an apparatus for that purpose, leading to an increase in cost. Further, when light is incident on the liquid surface at a large incident angle (when the incident angle of the exposure light with respect to the exposure mask 40 is large), the exposure light is totally reflected on the liquid surface, and the exposure light reaches the exposure mask. There is also the problem of not doing.

  Specifically, in the case of pure water having a refractive index of 1.44, if light is incident at an angle of about 45 degrees with respect to the liquid surface, the light is totally reflected, so that light is incident at a larger incident angle. It is not possible. Therefore, it is desirable that the exposure light is incident perpendicular to the liquid surface from the viewpoint of the configuration of the exposure apparatus. When a wide-angle taper is formed by tilt exposure using the immersion exposure apparatus, the transmission correction plate as described above is used. The embodiment to be used is preferable.

  In addition, a light receiving sensor 92 is provided in the immersion container 16 so that the amount of light reflected by the exposure mask 40 can be measured. Thereby, it can be confirmed whether the attachment position of the exposure mask 40 and the inclination angle of the stage 20 are installed at predetermined positions and angles. When the exposure mask 40 is floating with respect to the stage 20, since the direction of the reflected light is changed by the rotation of the stage 20, the amount of reflected light from the exposure mask 40 detected by the light receiving sensor 92 is Changes with rotation. Therefore, it is possible to detect whether or not the exposure mask 40 is securely fixed to the stage 20 by the variation in the amount of reflected light. Further, when the tilt angle of the stage 20 is not set at a predetermined tilt angle, the tilt angle of the stage 20 can be adjusted based on the amount of light reflected by the light receiving sensor 92 so that the predetermined tilt angle is obtained. It is.

  Furthermore, in this example, as described above, the tilt mechanism portion 94 is configured by the rotary shaft 21 of the stage 20, the universal joint 74, the stage rotary motor 76, the linear motion guide 80, the slider 82, the tilt swing motor 84, and the like. However, the entire optical axis including the tilt mechanism 94, the immersion container 16 and the stage 20 supported by the tilt mechanism 94 can be rotated in a horizontal plane around an axis parallel to the optical axis of the exposure light. A rotation motor 96 is provided. Since the optical axis rotation motor 96 is configured to rotate around the optical axis, the uniformity of the light quantity distribution can be further enhanced.

[Nozzle plate and nozzle plate manufacturing method]
Next, various nozzle plates manufactured by the method for manufacturing a nozzle plate according to the present invention will be described in detail together with the manufacturing method for each embodiment.

(First embodiment)
FIG. 8 is a cross-sectional view illustrating an example of a nozzle plate according to the first embodiment. An arrow E in the drawing indicates a liquid discharge direction. In FIG. 8, for convenience of illustration, only two nozzles 51 are illustrated, but the number of nozzles 51 is not particularly limited.

  In FIG. 8, the nozzle plate 30 a includes a tapered opening layer 31 having a plurality of tapered openings 51 a that open to the liquid inflow surface 302, and a plurality of R shapes (curved surfaces) that open to the liquid discharge surface 301. And an R-shaped opening layer 32 having an R-shaped opening 51b.

  The tapered opening 51a has a shape in which the opening area becomes narrower from the liquid inflow surface 302 toward the liquid ejection surface 301 in the thickness direction of the nozzle plate 30a. The R-shaped opening 51b has a shape in which the opening area increases from the liquid inflow surface 302 toward the liquid ejection surface 301 in the thickness direction of the nozzle plate 30a. The tapered opening 51a and the R-shaped opening 51b are connected to each other to form a so-called “necked” nozzle 51.

  Here, at least the peripheral edge (edge) on the liquid ejection surface 301 side of the R-shaped opening 51b is a curved surface. In other words, the R-shaped opening 51b has a shape in which the liquid discharge side end continuous with the liquid discharge surface 301 is rounded.

  The R-shaped opening layer 32 includes a metal pattern film 321 (first conductive film) made of a metal thin film in which openings 320 corresponding to the arrangement pattern of the nozzles 51 are formed, and a tapered opening layer 31 of the metal pattern film 321. The overhanging metal film 322 (second conductive) made of a thin metal film that covers the entire surface opposite to the surface in contact with the surface (liquid ejection side) and overhangs from the edge of the opening 320 of the metal pattern film 321 to the inner wall surface of the opening 320. Film).

  Among such R-shaped opening layers 32, at least the overhanging metal film 322 has non-translucency that does not transmit exposure light.

  In addition, the overhanging metal film 322 includes a material that is liquid repellent with respect to the discharged liquid, while the tapered opening layer 31 does not include a liquid repellent material and has a lower liquid repellency than the overhanging metal film 322. It is set. That is, the contact angle of the liquid with respect to the overhanging metal film 322 is larger than the contact angle of the liquid with respect to the tapered opening layer 31.

  In other words, a structure in which the boundary between the tapered opening 51a and the R-shaped opening 51b (hereinafter referred to as “necked position”) and the boundary between the liquid-repellent region and the lyophilic region in the nozzle 51 are matched. It has become.

  FIG. 9 is an enlarged sectional view showing the nozzle 51 of FIG. 8 in an enlarged manner. In FIG. 9, the tapered opening 51a has a shape (conical frustum shape) in which the opening width (flow channel width) decreases linearly from the liquid inflow surface 302 side to the liquid ejection surface 301 side. The R-shaped opening 51b has an R shape in which the opening width (flow channel width) increases in a curved shape from the liquid inflow surface 302 side to the liquid ejection surface 301 side.

  The tapered opening 51a shown in FIG. 9 has a truncated cone shape in which the opening width is linearly reduced, but the tapered opening 51a ′ shown in FIG. 10 has a curved opening width. It has a shape (dome shape). Such a tapered opening 51a 'can be obtained by shortening the wavelength of the exposure light when forming the tapered opening 51a' (for example, 300 nm or less).

  The nozzle 51 having the truncated conical tapered opening 51a shown in FIG. 9 can widen the tapered opening 51a toward the liquid inflow side, and the tapered opening 51a is linear on the liquid inflow side. Inflow performance and discharge performance are excellent. On the other hand, the nozzle 51 having the dome-shaped tapered opening 51a 'shown in FIG. 10 is advantageous when minimizing the opening area on the liquid inflow side.

  A plan view of an example of the metal pattern film 321 is shown in FIG. In FIG. 11, the openings 320 of the metal pattern film 321 are formed in the same arrangement pattern as the arrangement pattern of the nozzles 51 (for example, a two-dimensional arrangement as shown in FIG. 33A). The opening 320 of the metal pattern film 321 of this example is substantially circular, and the radius of the opening 320 is larger than the opening radius of the “necked position” of the nozzle 51 by the film thickness of the overhanging metal film 322. In addition, the shape of the opening of the nozzle 51 and the opening 320 of the metal pattern film 321 is not particularly limited to a circular shape in the present invention.

  12 (A) to 12 (F) and FIGS. 13 (G) to (I) are process diagrams used for explaining an example of the manufacturing process of the nozzle plate 30a of FIG.

  First, as shown in FIG. 12A, a dry film resist (DFR) is bonded and laminated on the entire surface of one surface of a so-called lotus type porous substrate 22 having a large number of holes. Then, a negative type resist 24 is attached to form a photosensitive layer 241. The film thickness of the resist 24 is, for example, 20 to 60 μm.

  Examples of the material for the porous substrate 22 include silicon, ceramics, and resin materials. Examples of the method for forming the porous substrate 22 include silicon anisotropic etching, ceramic firing, and resin formation.

  As a structure of the porous substrate 22, as schematically illustrated in FIG. 14A, a lotus-shaped structure in which the entire porous substrate 22 is made of a material having a large number of holes 220 is given as an example. As schematically shown in FIG. 14B, a structure in which a microporous film 221 having a large number of micropores is provided on the surface may be used.

  The resist 24 has negative photosensitivity that remains without being removed during development when irradiated with light for exposure having a predetermined wavelength, and is a conductive material in a eutectoid electroforming liquid by eutectoid electroforming described later. Has a resistance (non-conductivity) to the extent that hardly precipitates.

  Note that spin coating or squeegee coating may be performed instead of adhesion by dry film resist (DFR) lamination.

  Next, the resist 24 attached to the porous substrate 22 is baked.

  Next, as shown in FIG. 12B, a metal pattern film 321 made of a nickel (Ni) thin film is formed on the surface of the porous substrate 22 on which the photosensitive layer 241 is formed, using a lift-off method. .

  The material of the metal pattern film 321 is not particularly limited to nickel as long as it is a conductive material that can be used as an electrode for eutectoid electroforming described later.

  The opening width of the opening 320 of the metal pattern film 321 is larger than the opening width at the “neck” position of the nozzle 51 to be formed (the boundary between the tapered opening 51a and the R opening 51b in FIG. 8). It is larger by about twice the film thickness of 322 (for example, 1 to 5 μm).

  The formation of the metal pattern film 321 is not particularly limited to the lift-off method, and may be performed by, for example, trimming or paste printing.

  Next, as shown in FIG. 12C, the metal pattern film 321 is used as one electrode, a counter electrode is disposed on the electroforming growth side, and contains nickel (Ni) and PTFE (polytetrafluoroethylene). Eutectoid electroforming is performed using an electroforming solution (plating solution) to cover the surface of the metal pattern film 321 opposite to the side where the photosensitive layer 241 is formed (upper surface in the drawing), and the opening 320 of the metal pattern film 321. An overhanging metal film 322 is formed that overhangs from the edge of the substrate to the inner wall of the opening 320. Here, eutectoid electroforming is performed until the overhanging metal film 322 has a predetermined thickness (for example, 1 to 5 μm).

  In electroforming, since only a metal portion that is a conductive material is deposited, the upper surface of the metal pattern film 321 and the inner wall of the opening 320 are uniformly formed by a thin overhanging metal film 322 containing nickel and PTFE of a liquid repellent material. It is covered with a film thickness, and has an R shape (curved surface shape) at the edge of the opening 320 of the metal pattern film 321. The curvature of the R shape is determined by the thickness of the thin overhanging metal film 322. That is, an overhanging metal film 322 having a high-definition R shape is formed.

  Further, PTFE as a liquid repellent material is deposited together with nickel as an overhanging metal film 322 by eutectoid electroforming, so that the overhanging metal film 322 has not only conductivity but also liquid repellency.

  The electroforming liquid for eutectoid electroforming is not particularly limited when it contains nickel and PTFE, and can be used as an exposure mask and can be used as an electrode for electroforming described later. And a liquid repellent material that has liquid repellency with respect to the discharged liquid, and any of these conductive materials and liquid repellent materials may be co-deposited.

  Next, as shown in FIG. 12D, the porous substrate 22 is rotated while irradiating exposure light from an oblique direction to the surface of the photosensitive layer 241 where the R-shaped opening layer 32 is formed. Then, by performing exposure (hereinafter referred to as “tilt rotation exposure”) for exposing the photosensitive layer 241 using the R-shaped opening layer 32 as an exposure mask (40 in FIG. 1), light is applied only to the R-shaped opening 51b. A tapered photosensitive portion 25 a is formed in the resist 24 by passing through.

  In such tilt rotation exposure, a structure including a porous substrate 22, a resist 24, and an R-shaped opening layer 32 is placed on the stage 20 of the exposure apparatus 10 in FIG. 1 as shown in FIG. And do it.

  Next, as shown in FIG. 12E, a negative resist 24 is applied in the R-shaped opening 51b to seal the R-shaped opening 51b.

  Next, the resist 24 in the R-shaped opening 51b is baked.

  Next, as shown in FIG. 12 (F), the R-shaped opening layer 32 is irradiated with exposure light vertically, and the resist 24 in the R-shaped opening 51b is exposed to light so that the reverse taper-shaped photosensitivity is obtained. A portion 25b is formed. The taper-shaped photosensitive portion 25a is reinforced by such a reverse taper-shaped photosensitive portion 25b.

  Although the negative type resist 24 is applied in the R-shaped opening 51b in the step of FIG. 12E and this negative type resist 24 is exposed in the exposure step of FIG. In the process of FIG. 12E, a positive type resist may be applied in the R-shaped opening 51b, and the exposure process of FIG. 12F may be omitted. Further, the R-shaped opening 51b may be sealed with a sealing material other than the resist.

  Next, development is performed to remove the non-photosensitive portion of the photosensitive layer 241. Then, as shown in FIG. 13G, the tapered photosensitive portion 25a, which is the mold of the tapered opening (51a in FIG. 8) to be formed, and the reverse taper sealing the R-shaped opening 51b. The shape photosensitive portion 25b remains.

  Next, baking is performed on the tapered photosensitive portion 25a and the reverse tapered photosensitive portion 25b.

  Next, as shown in FIG. 13H, the taper-shaped photosensitive portion 25a is used as a mold, and the R-shaped opening layer 32 (the metal pattern film 321 and the overhanging metal film 322) is used as one electrode, and the electroforming growth side. The counter electrode is arranged on the electrode, and electroforming (nickel electroforming) is performed with an electroforming liquid containing nickel, and the tapered opening layer 31 having the tapered opening 51a is joined to the R-shaped opening layer 32. And accumulate. The thickness of the tapered opening layer 31 is 10 to 50 μm, for example.

  At the time of this electroforming, an electroforming liquid and an electric current can be quickly passed through the porous substrate 22. Means for circulating the electroforming liquid from the side surface of the porous substrate 22 are also effective.

  Next, as shown in FIG. 13I, the tapered photosensitive portion 25a and the reverse tapered photosensitive portion 25b are removed with an organic solvent, and the porous substrate 22 is peeled off. The surface of the tapered opening layer 31 may be polished as indicated by the dotted line in the figure.

  12A to 12F, the taper-shaped photosensitive portion 25a and the reverse taper-shaped photosensitive portion are subjected to two exposures (tilt rotation exposure in FIG. 12D and vertical exposure in FIG. 12F). Although the case where 25b was formed was demonstrated to the example, it is not specifically limited in such a case.

  A case where the tapered photosensitive portion 25a and the reverse tapered photosensitive portion 25b are formed by one exposure (only inclined rotation exposure) will be described with reference to FIGS.

  15A to 15C are the same as FIGS. 12A to 12C, respectively. In the state where the porous substrate 22, the photosensitive layer 241 and the R-shaped opening layer 32 are laminated as shown in FIG. 15C, a negative type is formed in the R-shaped opening 51b as shown in FIG. 15D. A resist 24 is applied to seal the R-shaped opening 51b. Next, the resist 24 in the R-shaped opening 51b is baked. Next, as shown in FIG. 15E, a tapered photosensitive portion 25a and an inversely tapered photosensitive portion 25b are collectively formed by tilt rotation exposure. The tilt rotation exposure has already been described with reference to FIG. 12D, and the subsequent steps have already been described with reference to FIGS. 13G to 13I. Therefore, the description thereof is omitted here.

(Second Embodiment)
FIG. 16 is a cross-sectional view illustrating an example of a nozzle plate according to the second embodiment. An arrow E in the drawing indicates a liquid discharge direction. In FIG. 16, for convenience of illustration, only two nozzles 51 are depicted, but the number of nozzles 51 is not particularly limited. In FIG. 16, the same components as those of the nozzle plate 30a of the first embodiment shown in FIG. 8 are denoted by the same reference numerals, and the description of the already described contents is omitted here.

  As shown in FIG. 16, the nozzle plate 30 b of this embodiment has a plurality of concave counterbore portions 33 formed on the liquid ejection surface 301.

  A bottom view of the liquid ejection surface 301 of the nozzle plate 30b of FIG. 16 is shown in FIG. FIG. 16 is a cross-sectional view taken along the line 16V-16V in FIG.

  As shown in FIGS. 16 and 17, the nozzle plate 30 b of this embodiment includes a tapered opening layer 31, an R-shaped opening layer 32 (a metal pattern film 321 and an overhang electroformed film 322), and a liquid discharge surface layer 323. It consists of. A counterbore portion 33 is formed on the liquid ejection surface layer 323.

  The counterbore part 33 is open to the liquid ejection surface 301 of the nozzle plate 30 b, and is connected to the R-shaped opening part 51 b of the nozzle 51. In other words, the R-shaped opening 51 b is connected to the bottom surface of the counterbore portion 33 that opens to the liquid discharge surface 301. The opening area of the counterbore part 28 is larger than the opening area of the liquid discharge side end of the nozzle 51 (the opening area of the liquid discharge side end of the R-shaped opening 51b). Such counterbore part 33 has the effect | action which protects the nozzle 51 at the time of wiping or jamming.

  18A to 18F and FIGS. 19G to 19J are process diagrams used for explaining an example of the manufacturing process of the nozzle plate 30b of FIG.

  The processes shown in FIGS. 18A to 18D are the same as those in the first embodiment shown in FIGS. 12A to 12D, respectively. As shown in FIG. 18A, a negative type resist 24 is attached to the entire surface of one surface of the porous substrate 22 to form a first photosensitive layer 241, and as shown in FIGS. 18B and 18C, An R-shaped opening layer 32 (a metal pattern film 321 and an overhang electroformed film 322) is formed, and a tapered photosensitive portion 25a is formed by tilt rotation exposure as shown in FIG.

  Next, as shown in FIG. 18E, a resist 24 is further adhered to the entire surface of the R-shaped opening layer 32 on the side opposite to the side where the first photosensitive layer 241 is formed. A photosensitive layer 242 is formed. Here, the resist is also filled in the R-shaped opening 51b.

  Next, the resist 24 is baked.

  Next, as shown in FIG. 18F, a light blocking film 41a having an opening 410a having the same opening area as the counterbore part to be formed (33 in FIG. 16) is used as an exposure mask (40 in FIG. 1). Vertical exposure is performed in which exposure light is incident on the second photosensitive layer 242 substantially perpendicularly to form a liquid discharge surface photosensitive portion 25c serving as a mold of a counterbore portion (33 in FIG. 16) to be formed.

  FIG. 18F shows the case where the light blocking film 41a is provided away from the second photosensitive layer 242, but is not particularly limited to such a case, and the light blocking film 41a is formed as the second photosensitive layer. It may be formed on layer 242 and removed after vertical exposure.

  Next, development is performed to remove the non-photosensitive portions of the first photosensitive layer 241 and the second photosensitive layer 242. Then, as shown in FIG. 19 (G), the tapered photosensitive portion 25a serving as a mold of the tapered opening (51a in FIG. 16) to be formed and the counterbore portion (33 in FIG. 16) to be formed. The liquid discharge surface photosensitive portion 25c serving as a mold remains without being removed.

  Next, the taper-shaped photosensitive portion 25a and the liquid discharge surface photosensitive portion 25c are baked.

  Next, as shown in FIG. 19H, the tapered opening layer 31 is formed by nickel electroforming using the tapered photosensitive portion 25a as a mold. This step is the same as the step shown in FIG. 13H of the first embodiment, and detailed description thereof is omitted. The thickness of the tapered opening layer 31 is 10 to 50 μm, for example.

  The liquid discharge surface photosensitive portion 25c that has not been removed in the above-described developing process not only functions as a mold for the counterbore portion 33 but also includes a R-shaped opening layer 32, a tapered photosensitive portion 25a, and a porous substrate 22. It also has the function of improving the rigidity of the body, which stabilizes the electroforming quality.

  Next, as shown in FIG. 19I, eutectoid electroforming is performed using an electroforming solution containing nickel and PTFE using the liquid discharge surface photosensitive portion 25c as a mold, and the liquid discharge having the counterbore portion 33 is performed. A surface layer 323 is formed. Here, eutectoid electroforming is performed until the liquid discharge surface layer 323 has a predetermined thickness (for example, 1 to 5 μm).

  Next, as shown in FIG. 19J, the tapered photosensitive portion 25a and the liquid discharge surface photosensitive portion 25c are removed with an organic solvent, and the porous substrate 22 is peeled off. The surface of the tapered opening layer 31 may be polished.

  In addition, although the case where the counterbore part 33 was formed in the liquid discharge surface 301 was demonstrated to the example using FIGS. 16-19, it is not specifically limited in such a case. A concave groove (35 in FIG. 24) located around the R-shaped opening 51b may be formed on the liquid ejection surface 301. Both the counterbore part 33 and the groove part may be formed on the liquid ejection surface 301, or only the groove part may be formed.

(Third embodiment)
FIG. 20 is a cross-sectional view illustrating an example of a nozzle plate according to the third embodiment. An arrow E in the drawing indicates a liquid discharge direction. In FIG. 20, for convenience of illustration, only two nozzles 51 are illustrated, but the number of nozzles 51 is not particularly limited. In FIG. 20, the same components as those of the nozzle plate 30a of the first embodiment shown in FIG. 8 are denoted by the same reference numerals, and the description of the already described contents is omitted here.

  As shown in FIG. 20, the nozzle plate 30 c of this embodiment has a plurality of concave grooves 34 (recesses) formed on the liquid inflow surface 302.

  An enlarged plan view of the liquid inflow surface 302 of the nozzle plate 30c is shown in FIG. FIG. 20 is a cross-sectional view taken along the line 20V-20V in FIG.

  The groove portion 34 of the liquid inflow surface 302 is formed symmetrically around the nozzle 50 around the central axis of the nozzle 50. 21 shows an arc-shaped groove 34 as an example, but the shape of the groove 34 of the liquid inflow surface 302 is not particularly limited.

  The groove 34 has an action of relaxing thermal stress generated in the nozzle plate 30c when the nozzle plate 30c and another flow path component (for example, 156 in FIG. 34) are joined or when the environmental temperature changes.

  22 (A) to 22 (E) and FIGS. 23 (F) to 23 (H) are process diagrams used for explaining an example of a manufacturing process of the nozzle plate 30c of FIG.

  First, as shown in FIG. 22A, a negative resist 24 is adhered to the photosensitive layer 241 by laminating and laminating a dry film resist (DFR) on the entire surface of one surface of the porous substrate 22. Form. The film thickness of the resist 24 is, for example, 20 to 60 μm.

  Next, the photosensitive layer 241 is baked.

  Next, as shown in FIG. 22B, a light blocking film 41b having an opening 410b having the same opening area as the groove to be formed (34 in FIG. 20) is used as an exposure mask (40 in FIG. 1). By vertically exposing the photosensitive layer 241 through the light blocking film 41b, a supporting photosensitive portion 25d (supporting material) that supports the tapered photosensitive portion 25a to be formed in a later process (shown in FIG. 22E). ). Here, in the vertical exposure, light for exposure is incident on the photosensitive layer 241 perpendicularly (that is, with an incident angle of 0 degree), and the exposed portion of the photosensitive layer 241 has a thickness of the photosensitive layer 241. The photosensitive layer 241 is exposed until it penetrates in the vertical direction.

  Next, the light blocking film 41b is removed with an organic solvent.

  The processes shown in FIGS. 22C to 22E are the same as the processes of the first embodiment shown in FIGS. 12B to 12D, respectively. Since they have already been described, detailed description will be given here. Omitted. Briefly, as shown in FIGS. 22C and 22D, an R-shaped opening layer 32 (metal pattern film 321 and overhanging metal film 322) is formed, and FIG. As shown in FIG. 1, by using the R-shaped opening layer 32 as an exposure mask (40 in FIG. 1), light is allowed to pass through only the R-shaped opening 51b by tilt rotation exposure, and the tapered photosensitive portion 25a is formed in the photosensitive layer 241. Form.

  Next, development is performed to remove the non-photosensitive portion of the photosensitive layer 241. Then, as shown in FIG. 23 (F), a tapered photosensitive portion 25a that becomes a mold of the tapered opening (51a in FIG. 20) to be formed, and a supporting photosensitive portion 25d that supports the tapered photosensitive portion 25a. Remains. The support photosensitive portion 25 d is interposed between the R-shaped opening layer 32 (specifically, the metal pattern film 321) and the porous substrate 22.

  Further, the support photosensitive portion 25d serves as a groove 34 shown in FIGS. The supporting photosensitive portion 25d is located around the tapered photosensitive portion 25a and is formed symmetrically about the central axis of the tapered photosensitive portion 25a (that is, the central axis of the nozzle 51). Specifically, the support photosensitive portion 25d is disposed symmetrically about the central axis of the tapered photosensitive portion 25a, and the support photosensitive portion 25d is formed in a symmetrical shape about the central axis of the tapered photosensitive portion 25a. .

  Next, as shown in FIG. 23G, the tapered photosensitive portion 25a and the supporting photosensitive portion 25d are used as a mold, and the R-shaped opening layer 32 (the metal pattern film 321 and the overhanging metal film 322) is used as an electrode. Then, electroforming (nickel electroforming) is performed with an electroforming solution containing nickel, and the tapered opening layer 31 having the tapered opening 51a and the groove 34 is deposited. The thickness of the tapered opening layer 31 is 10 to 50 μm, for example.

  Next, as shown in FIG. 23H, the tapered photosensitive portion 25a and the supporting photosensitive portion 25d are removed with an organic solvent, and the porous substrate 22 is peeled off. Note that the surface of the tapered opening layer 31 may be polished.

(Fourth embodiment)
FIG. 24 is a cross-sectional view illustrating an example of a nozzle plate according to the fourth embodiment. An arrow E in the drawing indicates a liquid discharge direction. In FIG. 24, for convenience of illustration, only two nozzles 51 are drawn, but the number of nozzles 51 is not particularly limited. In FIG. 24, the same components as those of the nozzle plate 30b with the counterbore portion 33 of the second embodiment shown in FIG. 16 are denoted by the same reference numerals, and the contents already described are described here. Omitted.

  As shown in FIG. 24, in the nozzle plate 30 d of the present embodiment, a plurality of concave grooves 34 are formed on the liquid inflow surface 302, and a plurality of concave grooves 35 and a plurality of grooves are formed on the liquid ejection surface 301. The concave-shaped counterbore part 33 is formed.

  A bottom view of the liquid ejection surface 301 of the nozzle plate 30d of FIG. 24 is shown in FIG. FIG. 24 is a sectional view taken along line 24V-24V in FIG.

  In FIG. 25, the groove 35 of the liquid ejection surface 301 is disposed between the nozzles 51 rows.

  As shown in FIGS. 24 and 25, the nozzle plate 30 of this embodiment includes a tapered opening layer 31, an R-shaped opening layer 32 (a metal pattern film 321 and an overhang electroformed film 322), and a liquid discharge surface layer 324. It consists of. A groove 35 and a counterbore 33 are formed in the liquid ejection surface layer 324.

  In addition, although the strip | belt-shaped groove part 35 is shown as an example in FIG. 25, the shape of the groove part 35 of the liquid discharge surface 301 is not specifically limited.

  22 (A) to 22 (E) and FIGS. 26 (F) to 26 (H) are process diagrams used for explaining an example of the manufacturing process of the nozzle plate 30d in FIG.

  Note that the steps shown in FIGS. 22A to 22E are the same as those in the third embodiment and have already been described, so the description thereof is omitted here.

  After the tapered photosensitive portion 25a is formed by the inclined rotation exposure shown in FIG. 22 (E), as shown in FIG. 26 (F), the side on which the first photosensitive layer 241 of the R-shaped opening layer 32 is formed. A second photosensitive layer 242 is formed by further attaching a resist 24 to the entire surface on the opposite side. Here, the resist is also filled in the R-shaped opening 51b.

  Next, the resist 24 is baked.

  Next, as shown in FIG. 26 (G), the opening 410c having the same width as the groove (35 in FIG. 24) on the liquid ejection surface 301 side to be formed and the counterbore (33 in FIG. 24) to be formed. A light blocking film 41c having an opening area 410a having the same opening area as the exposure mask (40 in FIG. 1) is formed by performing vertical exposure in which exposure light is incident on the second photosensitive layer 242 substantially perpendicularly. A liquid discharge surface photosensitive portion 25e serving as a mold of the groove portion 35 and the counterbore portion 33 to be formed is formed.

  FIG. 26G shows the case where the light blocking film 41c is provided apart from the second photosensitive layer 242, but is not particularly limited to such a case, and the light blocking film 41c is formed as the second photosensitive layer. It may be formed on layer 242 and removed after vertical exposure.

  Next, development is performed to remove the non-photosensitive portions of the first photosensitive layer 241 and the second photosensitive layer 242. Then, as shown in FIG. 26 (H), the tapered photosensitive portion 25a serving as the mold of the tapered opening (51a in FIG. 24) to be formed, the groove (35 in FIG. 24) and the counterbore to be formed. The liquid discharge surface photosensitive portion 25e which becomes the mold of the portion (33 in FIG. 24) remains without being removed.

  Next, the taper-shaped photosensitive portion 25a and the liquid discharge surface photosensitive portion 25e are baked.

  Next, as shown in FIG. 26I, the tapered opening layer 31 is formed by nickel electroforming using the tapered photosensitive portion 25a as a mold. This step is the same as the step shown in FIG. 13H of the first embodiment, and detailed description thereof is omitted. The thickness of the tapered opening layer 31 is 10 to 50 μm, for example.

  The liquid discharge surface photosensitive portion 25e that has not been removed in the above-described development process not only functions as a mold for the groove portion 35 and the counterbore portion 33 of the liquid discharge surface 301, but also has an R-shaped opening layer 32 and a tapered photosensitive portion 25a. In addition, it has a function of improving the rigidity of the structure made of the porous substrate 22, and this function stabilizes the electroforming quality.

  Next, as shown in FIG. 26J, eutectoid electroforming is performed using an electroforming solution containing nickel and PTFE, using the liquid discharge surface photosensitive portion 25e as a mold, and the counterbore portion 33 and the groove portion 35 are formed. A liquid discharge surface layer 324 having the same is formed. Here, eutectoid electroforming is performed until the liquid discharge surface layer 324 has a predetermined thickness (for example, 1 to 5 μm).

  Next, as shown in FIG. 26 (K), the tapered photosensitive portion 25a and the liquid discharge surface photosensitive portion 25e are removed with an organic solvent, and the porous substrate 22 is peeled off. The surface of the tapered opening layer 31 may be polished.

(Fifth embodiment)
FIG. 27 is a cross-sectional view showing an example of a nozzle plate according to the fifth embodiment. An arrow E in the drawing indicates a liquid discharge direction. In FIG. 27, for convenience of illustration, only two nozzles 51 are illustrated, but the number of nozzles 51 is not particularly limited. FIG. 28 is an enlarged sectional view showing one nozzle 51 in an enlarged manner. 27 and 28, the same components as the nozzle plate 30a of the first embodiment of FIG. 8, the same components as the nozzle plate 30b of the second embodiment of FIG. 16, and the nozzles of the third embodiment of FIG. The same components as those of the plate 30c and the nozzle plate 30d of the fourth embodiment in FIG. 24 are denoted by the same reference numerals, and the description of the already described contents is omitted here.

  As shown in FIGS. 27 and 28, the nozzle 51 of the nozzle plate 30e of the present embodiment includes a tapered opening 51a, a straight opening 51c continuous with the tapered opening 51a, and a straight opening 51c. It consists of a continuous R-shaped opening 51b. The tapered opening 51a has a shape in which the opening area becomes narrower from the liquid inflow surface 302 toward the liquid ejection surface 301 in the thickness direction of the nozzle plate 30e. The straight opening 51c has a shape with the same opening area in the thickness direction of the nozzle plate 30e. The R-shaped opening 51b has a shape in which the opening area increases from the liquid inflow surface 302 toward the liquid ejection surface 301 in the thickness direction of the nozzle plate 30e.

  Further, in the nozzle plate 30 e of this embodiment, a plurality of concave counterbore portions 33 are formed on the liquid ejection surface 301, and a plurality of concave grooves 34 are formed on the liquid inflow surface 302. The counterbore part 33 is the same as that of the nozzle plate 30d of the fourth embodiment shown in FIG. 24, and the groove 34 of the liquid inflow surface 302 is the same as that of the nozzle plate 30d of the fourth embodiment shown in FIG. Since they are the same and have already been described, the description thereof is omitted here.

  As shown in FIGS. 27 and 28, the nozzle plate 30e of the present embodiment has a tapered opening layer 31 in which a tapered opening 51a and a straight opening 51c are formed, and an R-shaped opening 51b. R-shaped opening layer 32 (metal pattern film 321 and overhang electroformed film 322) and liquid discharge surface layer 323. A groove 34 is formed in the tapered opening layer 31, and a counterbore portion 33 is formed in the liquid discharge surface layer 323.

  FIG. 27 shows the case where the groove 34 is formed only on the liquid inflow surface 302. However, the present invention is not particularly limited to this case, and the nozzle plate 30d of the fourth embodiment shown in FIG. As described above, the groove 35 may also be formed in the liquid discharge surface 301.

  29 (A) to 29 (G) and FIGS. 30 (H) to 30 (K) are process diagrams used for explaining an example of the manufacturing process of the nozzle plate 30e in FIG.

  The processes shown in FIGS. 29A to 29D are the same as the processes in the third embodiment shown in FIGS. 22A to 22D, respectively. As shown in FIG. 29A, a negative type resist 24 is deposited on the entire surface of one surface of the porous substrate 22 to form a first photosensitive layer 241. As shown in FIG. As shown in FIGS. 29C and 29D, an R-shaped opening layer 32 (a metal pattern film 321 and an overhang electroformed film 322) having an R-shaped opening 51b is formed.

  Next, as shown in FIG. 29E, a negative resist 24 is further adhered to the entire surface of the R-shaped opening layer 32 opposite to the side on which the first photosensitive layer 241 is formed. Two photosensitive layers 242 are formed. Here, the resist 24 is also filled in the R-shaped opening 51b, and the first photosensitive layer 241 and the second photosensitive layer 242 are connected via the R-shaped opening 51b.

  Next, the resist 24 is baked.

  Next, as shown in FIG. 29F, the surface of the first photosensitive layer 241 on the side where the R-shaped opening layer 32 is formed (in this example, the surface on which the second photosensitive layer 242 is formed). The first photosensitive layer is subjected to vertical exposure in which exposure light is incident substantially vertically, and the exposure mask 40 and the R-shaped opening layer 32 in which the light blocking film 41a and the light interference film 42 are laminated are formed. 241 and the second photosensitive layer 242 are exposed.

  Here, the light blocking film 41a is the same as the light blocking film 41a used in the second embodiment shown in FIG. That is, the light blocking film 41a is made of a material that does not transmit exposure light, and has an opening 410a having the same opening area as the opening area of the counterbore part (33 in FIG. 27) to be formed.

  In this example, as shown in FIG. 27, the light blocking film 41a for forming the counterbore portion 33 on the liquid discharge surface 301 is used. However, like the nozzle plate 30d of the fourth embodiment shown in FIG. When a groove (35 in FIG. 24) is to be formed along with the counterbore 33 on the discharge surface 301, a light blocking film 41c shown in FIG. 26 (G) is used.

  The optical interference film 42 has a characteristic that the transmittance of the exposure light changes according to the incident angle of the exposure light. Further, the optical interference film 42 has an opening 420 having an opening area smaller than the opening area of a straight opening (51c in FIG. 27) to be formed.

  In the optical interference film 42 of this example, the transmittance decreases as the incident angle of the exposure light increases. For example, as shown in FIG. 6, i-line (wavelength = 365 nm) is used as exposure light, and the optical interference film 42 exhibits a transmittance of approximately 0% when the incident angle is, for example, 35 degrees. When the angle is 0 degree (perpendicular incidence), the one having the characteristic that the transmittance is maximum (in this example, 30% or more) is used. In addition, you may use the optical interference film of a different characteristic according to the wavelength of the light used for exposure, and the incident angle to utilize.

  In the exposure step of FIG. 29F, the incident angle of light with respect to the first photosensitive layer 241 and the second photosensitive layer 242 is 0 degree, and the exposure light is transmitted through the optical interference film 42, so that the first photosensitive layer is exposed. A screw-shaped photosensitive portion 25 f is formed in the 241 and the second photosensitive layer 242. The screw-shaped photosensitive portion 25f includes a circumferential side surface 26b (R-shaped side surface) corresponding to the R-shaped opening (51b in FIG. 27) and a circumferential side surface 26c (51c in FIG. 27). Straight shape side). The straight side surface 26c is continuous with the R-shaped side surface 26b.

  Next, as shown in FIG. 29G, the surface of the first photosensitive layer 241 on the side where the R-shaped opening layer 32 is formed (in this example, the surface on which the second photosensitive layer 242 is formed). In contrast, tilt rotation exposure is performed to rotate the porous substrate 22 while exposing light from an oblique direction, and an exposure mask 40 in which a light blocking film 41d and a light interference film 42 are laminated is used to form a first photosensitive film. Layer 241 is exposed.

  In the tilt rotation exposure shown in FIG. 29G, the exposure light does not pass through the optical interference film 42, and the screw-shaped photosensitive portion 25f shown in FIG. 29F is replaced with the drum-shaped photosensitive portion shown in FIG. Deforms to 24g. The drum-shaped photosensitive portion 25g includes a circumferential side surface 26b (R-shaped side surface) corresponding to the R-shaped opening (51b in FIG. 27) and a circumferential side surface 26c (51c in FIG. 27). Straight side surface) and circumferential side surface 26a (tapered side surface) corresponding to the tapered opening (51a in FIG. 27). The tapered side surface 26a is continuous with the straight shape side surface 26c.

  In other words, the R-shaped side surface 26b and the straight-shaped side surface 26c are formed by the vertical exposure shown in FIG. 29F, and the tapered side surface 26a is formed by the inclined rotation exposure shown in FIG.

  29 (F) and 29 (G) show the case where the exposure mask 40 composed of the light blocking film 41a and the light interference film 42 is provided apart from the second photosensitive layer 242, but in this case However, the exposure mask 40 may be formed on the second photosensitive layer 242 and removed after the vertical exposure.

  Next, development is performed to remove the non-photosensitive portions of the first photosensitive layer 241 and the second photosensitive layer 242. Then, as shown in FIG. 30A, the drum-shaped photosensitive portion 25g and the supporting photosensitive portion 25d remain.

  Next, the drum-shaped photosensitive portion 25g and the support photosensitive portion 25d are baked.

  Next, as shown in FIG. 30 (I), the drum-shaped photosensitive portion 25g and the support photosensitive portion 25d are used as a mold, and the R-shaped opening layer 32 (the metal pattern film 321 and the overhanging metal film 322) is used as an electrode. Then, electroforming (nickel electroforming) is performed with an electroforming solution containing nickel, and a tapered opening having a tapered opening 51a and a straight opening 51c between the porous substrate 22 and the R-shaped opening layer 32. Layer 31 is deposited. The thickness of the tapered opening layer 31 is 10 to 50 μm, for example.

  Next, as shown in FIG. 30 (J), the drum-shaped photosensitive portion 25g is used as a mold, and the R-shaped opening layer 32 (mainly the overhanging metal film 322) is used as an electrode, and electroforming containing nickel and PTFE. Eutectoid electroforming is performed with a liquid, and a liquid-repellent liquid discharge surface layer 323 having an opening as a counterbore portion 33 is formed on the overhanging metal film 322 of the R-shaped opening layer 32.

  Next, as shown in FIG. 30K, the drum-shaped photosensitive portion 25g and the supporting photosensitive portion 25d are removed with an organic solvent, and the porous substrate 22 is peeled off. The surface of the tapered opening layer 31 may be polished.

  Although the case where the counterbore portion 33 is formed on the liquid discharge surface 301 has been described as an example, a groove portion (35 in FIG. 24) may be formed on the liquid discharge surface 301. Both the counterbore part 33 and the groove part 35 may be formed on the liquid ejection surface 301.

  Further, when neither the counterbore part 33 nor the groove part 35 is formed on the liquid discharge surface 301, the second photosensitive layer 242 shown in FIG. 29E is omitted, and in the vertical exposure step shown in FIG. The vertical exposure may be performed using only the R-shaped opening layer 32 without using the exposure mask 40 made of the blocking film and the optical interference film, and it is intended to be formed in the inclined rotation exposure process shown in FIG. The tilt rotation exposure may be performed using a light blocking film (not shown) having an opening 420 having an opening area smaller than the opening area of the straight opening (51c in FIG. 27).

[Overall configuration of inkjet recording apparatus]
Next, an example of an ink jet recording apparatus provided with an ink jet head using a nozzle plate manufactured by the nozzle plate manufacturing method according to the embodiment of the present invention will be described.

  FIG. 31 is an overall configuration diagram showing an outline of an ink jet recording apparatus which is an image forming apparatus according to an embodiment of the present invention. As shown in FIG. 31, the inkjet recording apparatus 210 includes a printing unit having a plurality of liquid ejection heads (hereinafter simply referred to as “heads”) 212K, 212C, 212M, and 212Y provided for each color of ink. 212, an ink storage / loading unit 214 that stores ink to be supplied to each of the heads 212K, 12C, 12M, and 12Y, a paper feeding unit 218 that supplies recording paper 216, and a decurl that removes curl from the recording paper 216 An adsorption belt that is disposed to face the processing unit 220 and the nozzle surfaces (ink ejection surfaces) of the heads 212K, 212C, 212M, and 212Y and conveys the recording paper 216 while maintaining the flatness of the recording paper 216 (recording medium). Remove the transport unit 222, the print detection unit 224 that reads the print result of the print unit 212, and the printed recording paper (printed material). And a paper output unit 226 for discharging the.

  The ink storage / loading unit 214 includes ink tanks that store inks of colors corresponding to the heads 212K, 212C, 212M, and 212Y, and the tanks 212K, 212C, 212M, and 212Y are connected to each other through a required pipe line. Communicated with. In addition, the ink storage / loading unit 214 includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. ing.

  In FIG. 26, a magazine for rolled paper (continuous paper) is shown as an example of the paper supply unit 218, but a plurality of magazines having different paper widths, paper quality, and the like may be provided side by side. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  When multiple types of recording paper are used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Therefore, it is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 216 delivered from the paper supply unit 218 retains curl due to having been loaded in the magazine. In order to remove the curl, heat is applied to the recording paper 216 by the heating drum 230 in the direction opposite to the curl direction of the magazine in the decurling unit 220. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  After the decurling process, the recording paper 216 cut to a predetermined size by the cutter 228 is sent to the suction belt conveyance unit 222. The suction belt conveyance unit 222 has a structure in which an endless belt 233 is wound between rollers 231 and 232 and faces at least the nozzle surfaces of the heads 212K, 212C, 212M, and 212Y and the sensor surface of the print detection unit 224. The part to be made is a flat surface.

  The belt 233 has a width that is greater than the width of the recording paper 216, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 31, an adsorption chamber 234 is provided at a position facing the nozzle surface of the print unit 212 and the sensor surface of the print detection unit 224 inside the belt 233 spanned between the rollers 231 and 232. Then, the suction chamber 234 is sucked by the fan 235 to be a negative pressure, whereby the recording paper 216 on the belt 233 is sucked and held.

  The power of a motor (not shown) is transmitted to at least one of the rollers 231 and 232 around which the belt 233 is wound, whereby the belt 233 is driven in the clockwise direction in FIG. 31 and held on the belt 233. The recording paper 216 is conveyed from left to right in FIG. In addition, instead of the suction suction method, an aspect using an electrostatic suction type transport mechanism is also possible.

  Since ink adheres to the belt 233 when a borderless print or the like is printed, the belt cleaning unit 236 is provided at a predetermined position outside the belt 233 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 236 are not illustrated, for example, there are a method of niping a brush roll, a water absorption roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  A heating fan 240 is provided on the upstream side of the printing unit 212 on the paper conveyance path formed by the suction belt conveyance unit 222. The heating fan 240 heats the recording paper 216 by blowing heated air onto the recording paper 216 before printing. Heating the recording paper 216 immediately before printing makes it easier for the ink to dry after landing.

  Each of the heads 212K, 212C, 212M, and 212Y of the printing unit 212 has a length corresponding to the maximum paper width of the recording paper 216 targeted by the ink jet recording apparatus 210, and the nozzle surface has a recording medium of the maximum size. This is a full-line type head in which a plurality of nozzles for ejecting ink are arranged over a length exceeding at least one side (full width of the drawable range) (see FIG. 32).

  The heads 212K, 212C, 212M, and 212Y are arranged in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side along the feeding direction of the recording paper 216. 212K, 212C, 212M, and 212Y are fixedly installed so as to extend along a direction substantially orthogonal to the conveyance direction of the recording paper 216.

  A color image can be formed on the recording paper 216 by ejecting different color inks from the heads 212K, 212C, 212M, 212Y while conveying the recording paper 216 by the suction belt conveyance unit 222.

  As described above, according to the configuration in which the full-line heads 212K, 212C, 212M, and 212Y having nozzle rows that cover the entire width of the paper are provided for each color, the recording paper 216 and the printing unit in the paper feeding direction (sub-scanning direction). The image can be recorded on the entire surface of the recording paper 216 by performing the operation of moving the 212 relatively once (that is, by one sub-scan). Thereby, high-speed printing is possible and productivity can be improved as compared with a serial scan type (shuttle type) head in which the recording head reciprocates in a direction perpendicular to the paper conveyance direction.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an ink jet head that discharges light ink such as light cyan and light magenta. Also, the arrangement order of the color heads is not particularly limited.

  The print detection unit 224 illustrated in FIG. 31 includes an image sensor (line sensor or area sensor) for imaging the droplet ejection result of the printing unit 212, and nozzle clogging is performed from the droplet ejection image read by the image sensor. It functions as a means for checking ejection failures such as landing position deviation. Test patterns or practical images printed by the heads 212K, 212C, 212M, and 212Y of the respective colors are read by the print detection unit 224, and ejection determination of each head is performed. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 242 is provided following the print detection unit 224. The post-drying unit 242 is means for drying the printed image surface, and for example, a heating fan is used.

  A heating / pressurizing unit 244 is provided following the post-drying unit 242. The heating / pressurizing unit 244 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 245 having a predetermined uneven surface shape while heating the image surface, and transfers the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 226. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 210 is provided with a sorting means (not shown) for switching the paper discharge path in order to select the printed matter of the main image and the printed matter of the test print and send them to the respective discharge portions 226A and 226B. Yes. When the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by the cutter (second cutter) 248. Although not shown in FIG. 26, the paper output unit 226A for the target prints is provided with a sorter for collecting prints according to print orders.

[Head structure]
Next, the structure of the head will be described. Since the structures of the respective heads 212K, 212C, 212M, and 212Y for each color are common, the heads will be represented by the reference numeral 250 in the following.

  FIG. 33A is a perspective plan view showing a structural example of the head 250. As shown in FIG. 33 (a), the head 250 of this example has an ink chamber unit (recording corresponding to one nozzle) composed of a nozzle 51, which is an ink droplet ejection port, and a pressure chamber 252 corresponding to each nozzle 51. It has a structure in which droplet discharge elements 253 as element units are arranged in a zigzag matrix (two-dimensionally), so that they are arranged along the longitudinal direction of the head (direction perpendicular to the paper feed direction). High density of the substantial nozzle interval (projection nozzle pitch) projected onto the screen is achieved. The nozzle 51 is the nozzle described with reference numeral 51 in FIG. 8, FIG. 16, FIG. 20, FIG.

  In addition, a nozzle row having a length corresponding to the entire width of the recording medium 216 is formed in a direction (arrow M direction; main scanning direction) substantially orthogonal to the feeding direction of the recording medium 216 (arrow S direction; sub-scanning direction). The form is not limited to this example. For example, instead of the configuration of FIG. 33A, as shown in FIG. 33B, short head units 250 ′ in which a plurality of nozzles 51 are two-dimensionally arranged are arranged in a staggered manner and connected. The line head having a nozzle row having a length corresponding to the entire width of the recording medium 216 may be configured.

  The pressure chambers 252 provided corresponding to the respective nozzles 51 have a substantially square planar shape, and the outlets to the nozzles 51 and the supply ink inlets (supply ports) are provided at both diagonal corners. 254 is provided. Note that the shape of the pressure chamber 252 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse. Further, the arrangement of the nozzle 51 and the supply port 254 is not limited to the arrangement shown in FIGS. 33A and 33B, and for example, the nozzle 51 may be arranged in the substantially central portion of the pressure chamber 252, or the pressure chamber A supply port 254 may be disposed on the side wall side of 252.

  FIG. 34 is a cross-sectional view showing a three-dimensional configuration of a droplet discharge element for one channel (an ink chamber unit 253 corresponding to one nozzle 51). 34 shows an example of the head 250 including the nozzle plate 30c of the third embodiment described in FIG. 20, but the nozzle plates of other embodiments (30a in FIG. 8, 30b in FIG. 16, 30 in FIG. 24) are shown. 30d, 30e of FIG. 27 is also possible.

  As shown in FIG. 34, the head 250 has a structure in which a nozzle plate 30, a communication plate 156, a common flow path forming plate 260, a diaphragm plate 262, a pressure chamber forming plate 264, a vibration plate 266, and a piezoelectric element 268 are laminated and joined. .

  The communication plate 156 forms a part of a communication path (nozzle flow path) 270 connecting from the pressure chamber 252 to the nozzle 51, and also forms a floor surface of a common flow path 272 for supplying ink to each pressure chamber 252. It is a member to do. The common flow path forming plate 260 is a flow path forming member that forms a portion that becomes the side wall portion of the common flow path 272 and also forms a part of the communication path 270.

  The diaphragm plate 262 forms an ink supply port 254 as a throttle part (a narrowest part) of an individual supply path that guides ink from the common channel 272 to the pressure chamber 252 and a channel that forms a part of the communication path 270. It is a forming member. The pressure chamber forming plate 264 is a flow path forming member that forms a portion that becomes a side wall portion of the pressure chamber 252.

  The diaphragm 266 is a member constituting a part of the pressure chamber 252 (the top surface in FIG. 29) and is made of a conductive material such as stainless steel (SUS), and corresponds to each pressure chamber 252. It also serves as a common electrode for a plurality of piezoelectric elements 268 to be arranged. It is also possible to form the diaphragm with a non-conductive material such as resin. In this case, a common electrode layer made of a conductive material such as metal is formed on the surface of the diaphragm member.

  On the surface of the diaphragm 266 opposite to the pressure chamber 252 side (upper side in FIG. 34), a piezoelectric body 274 is provided at a position corresponding to each pressure chamber 252, and the upper surface (common electrode) of the piezoelectric body 274 is provided. The individual electrode 275 is formed on the surface opposite to the surface in contact with the diaphragm 266 that also serves as the same. A piezoelectric element (corresponding to an “actuator”) 268 is constituted by the individual electrode 275, a common electrode (here also serving as the diaphragm 266) facing the individual electrode 275, and a piezoelectric body 274 interposed so as to be sandwiched between these electrodes. Is done. A piezoelectric material such as lead zirconate titanate or barium titanate is preferably used for the piezoelectric body 274.

  In the configuration of FIG. 34, the common flow path 272 communicates with an ink tank (not shown in FIG. 34, equivalent to the ink storage / loading unit 214 in FIG. 31) as an ink supply source, and is supplied from the ink tank. Ink is supplied to each pressure chamber 252 via the common flow path 272 of FIG.

  In a state where ink is filled in the pressure chamber 252, the piezoelectric element 268 is deformed by applying a driving voltage between the individual electrode 275 and the common electrode (also used as the vibration plate 266), and the volume of the pressure chamber 252 is changed, Ink is ejected from the nozzle 51 by the pressure change accompanying this. After the ink is ejected, when the displacement of the piezoelectric element 268 is restored, new pressure ink is refilled into the pressure chamber 252 from the common flow path 272 through the ink supply port 254.

  34, the taper-shaped opening layer 31 is arranged on the liquid inflow side and the R-shaped opening layer 32 is arranged on the liquid discharge side. However, as shown in FIG. The opening layer 31 may be disposed on the liquid discharge side, and the R-shaped opening layer 32 may be disposed on the liquid inflow side. Then, an R-shaped opening 51b having a small flow resistance is arranged on the liquid inflow side, and even if the R-shaped opening layer 32 having the R-shaped opening 51b is thinned, a wide-angle taper is formed on the liquid discharge side. The tapered opening layer 31 having the shape opening 51 a and thicker than the R shape opening layer 32 is arranged as a reinforcing layer of the R shape opening layer 32. That is, it is possible to further reduce the nozzle resistance on the liquid inflow side without reducing the rigidity in the vicinity of the nozzle opening.

  FIG. 35 shows an example of the head 250 including the nozzle plate 30c of the third embodiment described in FIG. 20, but a configuration employing the nozzle plate (30a of FIG. 8) of another embodiment is also possible. .

  FIG. 36 is a schematic diagram illustrating the configuration of an ink supply system and a discharge recovery device (maintenance unit) in the inkjet recording apparatus 210. The ink tank 290 is a base tank for supplying ink to the head 250, and is installed in the ink storage / loading unit 214 described with reference to FIG. In the form of the ink tank 290, there are a method of replenishing ink from a replenishing port (not shown) and a cartridge method of replacing the entire tank when the remaining amount of ink is low. When the ink type is changed according to the usage, the cartridge method is suitable. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type.

  As shown in FIG. 36, a filter 292 is provided in the middle of the conduit connecting the ink tank 290 and the head 250 in order to remove foreign substances and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter of the head 250 (generally about 20 μm).

  Although not shown in FIG. 36, a configuration in which a sub tank is provided in the vicinity of the head 250 or integrally with the head 250 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the head.

  Further, the inkjet recording apparatus 210 is provided with a cap 294 as a means for preventing the nozzle from drying or preventing an increase in ink viscosity near the nozzle, and a cleaning blade 296 as a means for cleaning the nozzle surface 250A.

  The maintenance unit including the cap 294 and the cleaning blade 296 can be moved relative to the head 250 by a moving mechanism (not shown), and is moved from a predetermined retracted position to a maintenance position below the head 250 as necessary. It is like that.

  The cap 294 is displaced up and down relatively with respect to the head 250 by an elevator mechanism (not shown). The lifting mechanism is configured to cover the nozzle region of the nozzle surface 250A with the cap 294 by raising the cap 294 to a predetermined raised position when the power is turned off or waiting for printing, and bringing the cap 294 into close contact with the head 250. In addition, the cap 294 functions as a suction unit for suctioning the nozzle and can also function as a preliminary discharge ink receiver.

  The cleaning blade 296 is made of an elastic member such as rubber, and can slide on the ink ejection surface (nozzle surface 250A) of the head 250 by a blade moving mechanism (not shown). When ink droplets or foreign matter adheres to the nozzle surface 250A, the nozzle surface 250A is wiped by sliding the cleaning blade 296 on the nozzle surface 250A to clean the nozzle surface 250A.

  During printing or standby, when a specific nozzle 51 is used less frequently and the ink viscosity in the vicinity of the nozzle 51 increases, preliminary ejection toward the cap 294 is performed in order to discharge the ink that has deteriorated due to the increased viscosity. Is done.

  That is, if the head 250 is not ejected for a certain period of time, the ink solvent near the nozzles evaporates and the viscosity of the ink near the nozzles increases, and the ejection driving actuator (piezoelectric element 268) operates. However, no ink is ejected from the nozzle 51. Therefore, before this state is reached (within the viscosity range in which ink can be ejected by the operation of the piezoelectric element 268), the piezoelectric element 268 is operated toward the ink receiver, and the ink in the vicinity of the nozzle whose viscosity has increased is removed. “Preliminary discharge” is performed. Further, after the dirt on the nozzle surface 250A is cleaned by a wiper such as a cleaning blade 296 provided as a cleaning means for the nozzle surface 250A, foreign matter is prevented from being mixed into the nozzle 51 by this wiper rubbing operation. Also, preliminary discharge is performed. Note that the preliminary discharge may be referred to as “empty discharge”, “purge”, “spitting”, or the like.

  When air bubbles are mixed in the ink in the head 250 (ink in the pressure chamber 252), the cap 294 is applied to the head 250, and the ink in the pressure chamber 252 (ink mixed with air bubbles) is sucked by the suction pump 297. The ink removed and sucked and removed is sent to the collection tank 298. This suction operation is also performed when the initial ink is loaded into the head or when the ink is used after being stopped for a long time, and the deteriorated ink solidified by increasing the viscosity is sucked and removed.

  Specifically, when air bubbles are mixed in the nozzle 51 or the pressure chamber 252 or the viscosity of the ink in the nozzle 51 exceeds a certain level, ink is ejected from the nozzle 51 in the preliminary ejection for operating the piezoelectric element 268. become unable. In such a case, the pump 297 sucks ink or thickened ink in which bubbles in the pressure chamber 252 are mixed by applying a cap 294 to the nozzle surface 250A of the head 250.

  However, since the above suction operation is performed on the entire ink in the pressure chamber 252, the amount of ink consumed is large. Therefore, when the increase in viscosity is small, it is preferable to perform preliminary discharge as much as possible. Preferably, the inside of the cap 294 is divided into a plurality of areas corresponding to the nozzle rows by a partition wall, and each of the partitioned areas can be selectively sucked by a selector or the like.

  In this embodiment, a full-line head is exemplified, but the scope of application of the present invention is not limited to this, and a short head having a nozzle row having a length shorter than the width of the recording medium is arranged in the width direction of the recording medium. The present invention is also applicable to a serial type (shuttle scan type) head that performs printing in the width direction of the recording medium while scanning.

  In the above-described embodiment, the method for manufacturing the nozzle plate of the inkjet head has been described. However, the applicable range of the nozzle plate manufactured by the method for manufacturing a nozzle plate according to the present invention is not limited to the above-described ink jet recording apparatus. It can be applied to droplet ejection heads used in various droplet ejection devices that eject (spray) liquids, such as industrial precision coating devices, resist printing devices, wiring drawing devices for electronic circuit boards, and dyeing devices. .

  The present invention is not limited to the examples described in the present specification and the examples illustrated in the drawings, and various design changes and improvements may be made without departing from the spirit of the present invention.

The block diagram which shows an example of the exposure apparatus used for the manufacturing method of the nozzle plate which concerns on embodiment of this invention Enlarged view of the exposure part of the exposure equipment Plan view showing an example of arrangement of light receiving sensors attached to the stage Configuration diagram of illumination unit used in exposure apparatus Diagram showing an example of light source spectrum Graph showing transmittance characteristics (incident angle dependency) of an example of an optical interference film The block diagram which shows the example of the inclination rotation mechanism in exposure apparatus Sectional drawing which shows an example of the nozzle plate of 1st Embodiment Enlarged sectional view of the nozzle of FIG. Expanded sectional view of other nozzles The top view which shows an example of the metal pattern film of the nozzle plate of FIG. Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the first embodiment Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the first embodiment Explanatory drawing showing an example of a porous substrate Process drawing used for explanation of another example of the manufacturing method of the nozzle plate of the first embodiment Sectional drawing which shows an example of the nozzle plate of 2nd Embodiment The bottom view which shows the surface by the side of the liquid discharge of the nozzle plate of FIG. Process drawing used for description of an example of the manufacturing method of the nozzle plate of the second embodiment Process drawing used for description of an example of the manufacturing method of the nozzle plate of the second embodiment Sectional drawing which shows an example of the nozzle plate of 3rd Embodiment FIG. 20 is a plan view showing the surface of the nozzle plate of FIG. 20 on the liquid inflow side. Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the third embodiment Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the third embodiment Sectional drawing which shows an example of the nozzle plate of 4th Embodiment The bottom view which shows the surface by the side of the liquid discharge of the nozzle plate of FIG. Process drawing used for description of an example of the manufacturing method of the nozzle plate of the fourth embodiment Sectional drawing which shows an example of the nozzle plate of 5th Embodiment Enlarged sectional view of the nozzle of FIG. Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the fifth embodiment Process drawing used for explaining an example of the manufacturing method of the nozzle plate of the fifth embodiment 1 is an overall configuration diagram of an ink jet recording apparatus as an example of an image forming apparatus according to the present invention. FIG. 31 is a plan view of the main part around the printing unit of the ink jet recording apparatus of FIG. Plane perspective view showing an example of the structure of an example of a liquid discharge head according to the present invention Sectional view showing an example of the internal structure of the liquid discharge head Sectional drawing which shows the other example of the internal structure of a liquid discharge head Schematic configuration diagram of an ink supply system in an ink jet recording apparatus

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Exposure apparatus, 12 ... Light source, 14 ... Irradiation optical system, 16 ... Immersion container, 18 ... Transmission correction plate, 20 ... Stage, 22 ... Porous substrate, 24 ... Resist, 25a ... Tapered photosensitive part, 25b ... Reverse taper-shaped photosensitive part, 25c, 25e ... liquid ejection surface photosensitive part, 25d ... support photosensitive part, 25f ... screw-shaped photosensitive part, 25g ... drum-shaped photosensitive part, 30 (30a, 30b, 30c, 30d, 30e) ... nozzle Plate, 31 ... Tapered opening layer, 32 ... R-shaped opening layer (opening layer with curved surface), 33 ... Counterbore part, 34, 35 ... Groove part, 40 ... Exposure mask, 41 (41a, 41b, 41c) ... Light blocking film , 42 ... Optical interference film, 51 ... Nozzle, 51 a ... Tapered opening, 51 b ... R opening (curved opening), 51 c ... Straight opening, 241 ... First photosensitive layer, 242 ... Second photosensitive , 301 ... liquid ejection surface, 302 ... liquid inflow surface, 321 ... metal pattern layer, 322 ... overhang electroforming film, 323, 324 ... liquid ejection surface layer

Claims (9)

Forming a photosensitive layer made of a photosensitive material on one surface of a predetermined substrate;
On the photosensitive layer, formed of a non-translucent material that does not transmit light for exposure, and a curved opening layer forming step of forming a curved opening layer having a curved opening with a curved periphery.
Using the curved opening layer as an exposure mask by rotating the substrate while exposing light from an oblique direction to the surface of the photosensitive layer where the curved opening layer is formed. An exposure step of forming a tapered photosensitive portion in the photosensitive layer by exposing the photosensitive layer; and
Developing the photosensitive layer to remove the non-photosensitive portion while leaving the tapered photosensitive portion in the photosensitive layer; and
A tapered opening layer forming step of forming a tapered opening layer having a tapered opening connected to the curved opening using the tapered photosensitive portion as a mold;
A removal step of removing the tapered photosensitive portion and the substrate;
The manufacturing method of the nozzle plate characterized by including. The curved opening layer forming step includes
A patterning step of forming a first conductive film having an opening pattern on the non-conductive photosensitive layer;
Electroforming is performed using the first conductive film as an electrode to form a non-translucent second conductive film that covers the first conductive film and overhangs from the opening edge of the first conductive film. An overhang electroforming process,
The manufacturing method of the nozzle plate of Claim 1 characterized by the above-mentioned.   The overhang electroforming step uses an electroforming liquid containing a metal material and a liquid repellent material, and causes the liquid repellent material in the electroforming liquid to eutect with the metal material as the second conductive film. The method for producing a nozzle plate according to claim 2. The substrate is made of a porous material,
The method for manufacturing a nozzle plate according to any one of claims 1 to 3, wherein the tapered opening layer forming step is performed by electroforming using the curved opening layer as an electrode.   Before the step of forming the curved opening layer, the tapered photosensitive film to be formed is formed by exposing a part of the photosensitive layer and exposing the photosensitive layer until it penetrates the photosensitive layer in the thickness direction. 5. The method according to claim 1, further comprising a support material forming step of forming a support material positioned around the portion and interposed between the substrate and the curved opening layer. 6. The manufacturing method of the nozzle plate of description.   After the curved opening layer forming step and before the developing step, a photosensitive material is attached to the surface of the curved opening layer opposite to the side where the photosensitive layer is formed. By using the photosensitive material as a mold without removing a part thereof in the development step, a concave counterbore portion connected to the curved opening and a periphery of the curved opening are located. The method for manufacturing a nozzle plate according to any one of claims 1 to 5, wherein at least one of the concave grooves is formed. An exposure mask having an optical interference film having a characteristic that the transmittance of the exposure light changes according to the incident angle of the exposure light, or light that does not transmit the optical interference film and the exposure light Prepare an exposure mask comprising a blocking film, or an exposure mask having the light blocking film,
Forming a photosensitive layer made of a photosensitive material on one surface of a predetermined substrate;
On the photosensitive layer, a curved opening layer forming step of forming a curved opening layer made of a non-translucent material that does not transmit the light for exposure and having a curved opening with a curved periphery.
The exposure light is incident substantially perpendicularly to the surface of the photosensitive layer on which the curved opening layer is formed, and the photosensitive layer is exposed using at least the curved opening layer. 1 exposure process;
Using the curved opening layer and the exposure mask, the substrate is rotated while exposing light from an oblique direction to the surface of the photosensitive layer on which the curved opening layer is formed. A second exposure step of exposing the photosensitive layer;
Developing the photosensitive layer to remove a non-photosensitive portion of the photosensitive layer;
Using the photosensitive part of the photosensitive layer as a mold, a tapered opening forming a tapered opening layer having a straight opening connected to the curved opening and a tapered opening connected to the straight opening. A layer forming step;
A removal step of removing the photosensitive portion of the photosensitive layer and the substrate;
The manufacturing method of the nozzle plate characterized by including.   A liquid discharge head comprising a nozzle plate manufactured by the method for manufacturing a nozzle plate according to claim 1.   An image forming apparatus comprising the liquid discharge head according to claim 8.

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