JP2009179030A - Method for manufacturing nozzle plate for liquid discharge head, nozzle plate for liquid discharge head, and liquid discharge head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide liquid ejection in which the inner wall of a hole formed in a water repellent layer connected to the inner wall of a nozzle hole has good water repellency and the opening diameter of the hole formed in the water repellent layer is equal to or larger than the opening diameter of the nozzle hole A head nozzle plate manufacturing method, a liquid discharge head nozzle plate, and a liquid discharge head are provided.
When a water repellent layer is formed on a plate through which a nozzle hole penetrates, a resin layer is formed immediately above the nozzle hole by photocuring, and then a plated layer containing particles of a water repellent resin is formed. The cured oil film is removed from the formed plate, the plated layer of the plate from which the cured oil film has been removed is etched, and heat is applied to the plated layer of the plate where the plated layer is etched. This is performed by softening the particles of the water-repellent resin exposed on the surface of the plating layer to produce a nozzle plate for a liquid discharge head.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing a nozzle plate for a liquid discharge head having a water-repellent layer around the nozzle hole and capable of maintaining a stable ink discharge state, a nozzle plate for a liquid discharge head, and a liquid discharge head using the same About.

  2. Description of the Related Art In recent years, with the spread of personal computers and the development of multimedia, the use of recording devices that use ink jet type liquid ejection devices as recording devices that output information to recording media is rapidly expanding.

  Such an ink jet recording apparatus is equipped with an ink jet head. This type of ink jet head is provided with a pressurizing means in an ink flow path filled with ink. The ink in the ink flow path is pressurized by the pressurizing means, and ink droplets are ejected from the ink discharge holes. Discharged. In addition, a thermal system that includes a heater as a pressurizing unit, heats and boiles the ink with the heater, and pressurizes the ink by bubbles generated in the ink flow path, and an ink that includes a piezoelectric element as the pressurizing unit and fills the ink There is generally known a piezoelectric system in which a part of a wall of a flow path is bent and displaced by a piezoelectric element to mechanically pressurize ink in an ink flow path.

  In order to discharge ink droplets stably against the pressurization of ink from the ink flow path, the ink meniscus is stably held in the nozzle holes, which are ink discharge holes. It is necessary. Therefore, a water-repellent water-repellent film is formed in the vicinity of the nozzle hole so that the meniscus does not come out of the nozzle hole and does not interfere with the ink adhered around the nozzle hole.

  As a method of manufacturing an inkjet nozzle plate having a water-repellent film formed in the vicinity of such nozzle holes, the following method shown in FIG. 8 has been proposed (for example, Patent Document 1). (A) A plate 801 having nozzle holes 802 is prepared. (B) The front surface of the plate 801 is covered with a photosensitive resin 803. (C) It exposes from the back surface of the plate 801, and a part of the photosensitive resin 803 is cured. (D) The uncured photosensitive resin 803 is removed, and the nozzle hole 802 is closed with the cured photosensitive resin 803-1. (E) A water repellent film 804 is formed on the front surface of the plate 801. (F) By removing the cured photosensitive resin 803-1, a nozzle plate having a water-repellent film 804 formed on the surface can be obtained. Also, the following method shown in FIG. 9 has been proposed (for example, Patent Document 2). (A) A plate 901 having nozzle holes 902 is prepared. (B) The resin 907 is filled from the back surface of the plate 901 to the middle of the nozzle hole 902. (C) A water repellent film 904 is formed on the surface of the plate 901. (D) The resin 907 is removed.

The water-repellent film 804 or the water-repellent film 904 is formed by applying a water-repellent resin or forming a plating layer containing water-repellent resin particles and softening the water-repellent resin particles.
JP 2006-289863 A JP-A-7-125220

  However, in the method of manufacturing a nozzle plate for a liquid discharge head disclosed in Patent Document 1, when a plating layer containing water-repellent resin particles is formed and the water-repellent resin particles are softened to form the water-repellent film 804, There is a problem that the water repellency of the inner wall of the hole of the water repellent film 804 connected to the hole 802 is not sufficient.

  FIG. 6 is a schematic cross-sectional view showing a state in which the above-described water-repellent film, that is, the plating layer 404 including the water-repellent resin 406 particles and the metal layer 405 is formed in the water-repellent film forming step of FIG. is there. On the surface 404a of the plating layer 404 facing the plate 401, the particles of the water repellent resin 406 are exposed. On the other hand, on the inner wall 404 b of the hole of the plating layer 404 connected to the nozzle hole 402, since the cured photosensitive resin 403-1 is present, the particles of the water repellent resin 406 are hardly exposed on the surface of the plating layer 404. The plating layer 404 containing the particles of the water-repellent resin 406 is heated in a later step to soften the particles of the water-repellent resin 406 so that the plating layer 404 is covered with the water-repellent resin film.

  However, as described above, the inner wall 404b of the hole of the plating layer 404 connected to the nozzle hole 402 has little exposure of the water-repellent resin 406, and thus the water-repellent resin 406 contained in the particles of the water-repellent resin 406 that softens even when heated. The amount of water-based resin 406 was insufficient, and a water-repellent resin film could not be formed sufficiently.

  Further, in the method of manufacturing a nozzle plate for a liquid discharge head disclosed in Patent Document 2, the water repellent film 904 is directed from the end of the water repellent film 904 inside the nozzle hole 902 where the meniscus is formed toward the direction in which the liquid is discharged. Since the nozzle diameter is reduced by the thickness of the liquid, the discharge of the liquid is hindered and the liquid discharge characteristics may be unstable. In particular, when the end portion of the water repellent film 504 is at a portion where the inner wall of the nozzle hole 502 is not perpendicular to the main surface of the nozzle plate 501 as shown in FIG. As a result, the diameter r of the portion where the meniscus is formed in the nozzle hole 502 is changed, so that the fluctuation of the liquid discharge characteristic may be increased.

  Therefore, the present invention provides a nozzle plate for a liquid discharge head in which the inner wall of the hole of the water repellent layer connected to the inner wall of the nozzle hole has good water repellency, and the opening diameter of the hole in the water repellent layer is equal to or larger than the opening diameter of the nozzle hole An object of the present invention is to provide a manufacturing method, a nozzle plate for a liquid discharge head, and a liquid discharge head using the same.

  The method for manufacturing a nozzle plate for a liquid discharge head according to the present invention includes a step A for forming a nozzle hole penetrating between main surfaces of the plate, and the plate so as to fill a part of one main surface side of the nozzle hole. Step B of supplying a photocurable resin to one main surface of the substrate to form a photocurable resin film, and the light filled in the nozzle holes by irradiating light from the other main surface side of the plate Step C for curing a part of the photocurable resin film including the curable resin film, Step D for removing the uncured photocurable resin film from the plate, and the uncured photocurable resin film Step E of forming a plating layer containing water-repellent resin particles on one main surface of the plate from which the resin has been removed, and removing the photocurable resin film cured from the plate on which the plating layer has been formed Step F and the cured photocurable resin film A step G of etching the plated layer of the removed plate, and a step of softening particles of the water-repellent resin exposed to the surface of the plated layer by applying heat to the plated layer of the plate from which the plated layer has been etched. And H.

  The method for manufacturing a nozzle plate for a liquid discharge head according to the present invention includes a step A for forming a nozzle hole penetrating between main surfaces of the plate, and the plate so as to fill a part of one main surface side of the nozzle hole. A photocurable resin is supplied to one main surface of the substrate to form a photocurable resin film, and a portion of the photocurable resin film is irradiated with light from the other main surface side of the plate. On the one main surface of the plate from which the uncured photocurable resin film has been removed, on the main surface of the plate from which the uncured photocurable resin film has been removed. A step E of forming a plating layer containing particles of the above, a step I of etching the plating layer of the plate having the cured photocurable resin film, and the plate cured from the plate on which the plating layer has been etched Excluding photo-curing resin film And a step K of applying heat to the plating layer of the plate from which the cured photocurable resin film has been removed to soften the particles of the water-repellent resin exposed on the surface of the plating layer. Features.

  Further, in the step C, it is preferable that the curing range of the photocurable resin film in the vicinity of the nozzle hole is made wider on the side not in contact with the plate than on the side in contact with the plate.

  In the step E, it is preferable that the content of the water-repellent resin contained in the plate-side region of the plating layer is higher than the content of the water-repellent resin contained in the surface-side region of the plating layer. .

  In the step E, it is preferable that the content of the water repellent resin included in the region immediately above the nozzle hole of the plating layer is higher than the content of the water repellent resin included in the outer region.

  The nozzle plate for a liquid discharge head according to the present invention includes a plate provided with nozzle holes, a water repellent resin film formed on one main surface of the plate, and a hole connected to the nozzle holes. A nozzle plate for a liquid discharge head having a water repellent layer, wherein the hole has a shape similar to the shape of the nozzle hole and is equal to or larger than the nozzle hole. Features.

  Moreover, it is preferable that the opening diameter on the opposite side to the nozzle hole is larger than the opening diameter on the nozzle hole side.

  Moreover, it is preferable that the said nozzle hole becomes large gradually toward the other main surface from one main surface of the said plate.

  The liquid discharge head of the present invention includes the liquid discharge head nozzle plate, a liquid pressurizing chamber connected to the nozzle hole of the nozzle plate, and a pressurizing unit that pressurizes the liquid in the liquid pressurizing chamber. Features.

  According to the method for manufacturing a nozzle plate for a liquid discharge head of the present invention, the step A for forming a nozzle hole penetrating between the main surfaces of the plate and the filling of a part on one main surface side of the nozzle hole are performed. Step B of supplying a photocurable resin to one main surface of the plate to form a photocurable resin film, and irradiating light from the other main surface side of the plate, filling the nozzle holes Step C for curing a part of the photocurable resin film including the photocurable resin film, Step D for removing the uncured photocurable resin film from the plate, and the uncured photocurable property Step E of forming a plating layer containing water-repellent resin particles on one main surface of the plate from which the resin film has been removed, and the photocurable resin film cured from the plate on which the plating layer has been formed. Step F to remove and the cured photocurability Etching the plating layer of the plate from which the oil film has been removed; and applying the heat to the plating layer of the plate from which the plating layer has been etched to expose the water-repellent resin particles exposed on the surface of the plating layer. By including the softening step H, the water-repellent resin is exposed also to the inner wall of the hole of the plating layer connected to the inner wall of the nozzle hole after the step G, and is connected to the inner wall of the nozzle hole by the heating in the step H. A sufficiently water-repellent resin film is also formed on the inner wall of the hole in the plating layer. In addition, since the opening diameter of the water repellent layer connected to the inner wall of the nozzle hole is equal to or larger than the opening diameter of the nozzle hole, the liquid ejection characteristics are hardly adversely affected.

  According to the method for manufacturing a nozzle plate for a liquid discharge head of the present invention, the step A for forming a nozzle hole penetrating between the main surfaces of the plate and the filling of a part on one main surface side of the nozzle hole are performed. Supplying a photocurable resin to one main surface of the plate to form a photocurable resin film; and irradiating light from the other main surface side of the plate; Step C for partially curing, Step D for removing the uncured photocurable resin film from the plate, and one main surface of the plate from which the uncured photocurable resin film has been removed Step E for forming a plating layer containing aqueous resin particles, Step I for etching the plating layer of the plate having the cured photocurable resin film, and curing from the plate on which the plating layer has been etched The photo-curable resin And step K for softening the particles of the water-repellent resin exposed to the surface of the plating layer by applying heat to the plating layer of the plate from which the cured photocurable resin film has been removed. Thus, after step I, the water-repellent resin is also exposed on the inner wall of the hole of the plating layer connected to the inner wall of the nozzle hole, and is heated on the inner wall of the plating layer connected to the inner wall of the nozzle hole by heating in step K. A sufficiently water-repellent resin film is formed. Further, since the opening diameter of the water repellent layer connected to the inner wall of the nozzle hole is equal to or larger than the opening diameter of the nozzle hole, it is difficult to adversely affect the liquid discharge characteristics.

  In the step C, when the curing range of the photocurable resin film in the vicinity of the nozzle hole is widened on the side not in contact with the plate rather than on the side in contact with the plate, the water repellent layer on the main surface of the plate and the inner wall of the nozzle hole Since the angle formed by the water-repellent layer connected to the nozzle becomes obtuse or smoothly connected, variation when the liquid separates from the water-repellent layer at the end of the nozzle hole is reduced, and variation in the discharge characteristics of the liquid can be reduced.

  In the step E, when the content of the water-repellent resin contained in the plate-side region of the plating layer is higher than the content of the water-repellent resin contained in the surface-side region of the plating layer, After G or Step I, the water-repellent resin particles are more exposed to the inner wall of the plating layer hole connected to the inner wall of the nozzle hole, particularly the end of the plating layer in the nozzle hole where the meniscus is formed, and more reliably. A water repellent resin can be formed.

  When the content of the water-repellent resin contained in the region immediately above the nozzle hole of the plating layer is higher than the content of the water-repellent resin contained in the outer region in the step E, the step G After that, the water-repellent resin particles are more exposed on the inner wall of the plated layer hole connected to the inner wall of the nozzle hole, particularly the end of the plated layer in the nozzle hole where the meniscus is formed, and the water-repellent resin is more reliably Can be formed.

  According to the nozzle plate for a liquid discharge head of the present invention, a water repellent resin film is formed on the surface of the plate provided with the nozzle holes and formed on one main surface of the plate, and is connected to the nozzle holes. A nozzle plate for a liquid discharge head having a water repellent layer having a hole, wherein the hole is similar in shape to the nozzle hole and is equal to or larger than the nozzle hole. As a result, there is no portion in which the hole diameter of the nozzle hole becomes smaller before the portion where the meniscus is formed, so that variations in the liquid ejection characteristics due to the influence can be suppressed.

  In addition, when the opening diameter on the side opposite to the nozzle hole is larger than the opening diameter on the nozzle hole side, the dispersion of the liquid when separating from the water repellent layer at the end of the nozzle hole is reduced, and the liquid discharge characteristics are reduced. Variation can be reduced.

  Further, when the nozzle hole is gradually increased from one main surface of the plate to the other main surface, the hole shape (opening shape of the nozzle hole viewed from the direction perpendicular to the main surface of the nozzle plate) Variations are reduced, and variations in liquid ejection characteristics can be reduced.

  According to the liquid discharge head of the present invention, the liquid discharge head includes a nozzle plate for the liquid discharge head, a liquid pressurization chamber connected to the nozzle hole of the nozzle plate, and a pressurizing unit that pressurizes the liquid in the liquid pressurization chamber. Thus, variation in the liquid ejection characteristics due to the influence of the nozzle holes ahead of the portion where the meniscus is formed can be suppressed.

  Hereinafter, an embodiment of a liquid discharge head of the present invention will be described in detail with reference to the drawings.

  FIG. 1A is a partial longitudinal sectional view of the liquid discharge head of this embodiment, and FIG. 1B is a top view. FIG. 1C is a partial cross-sectional view of the vicinity of a nozzle hole of a nozzle plate for a liquid discharge head according to the present invention.

  In the present embodiment, the liquid ejection head 1 is configured by laminating a flow path member 4 and a piezoelectric actuator 21.

In the flow path member 4, a plurality of liquid pressurizing chambers 3 and a plurality of nozzle holes 2 respectively connected to the plurality of liquid pressurizing chambers 3 are arranged in a matrix (that is, two-dimensionally and regularly). The flow path member 4 includes a liquid discharge head nozzle plate 4a (hereinafter simply referred to as a nozzle plate) in which a plurality of nozzle holes 2 are formed and plates 4b to 4i in which a plurality of liquid flow paths 5 are formed. In addition, a part of the liquid flow path 5 is a liquid pressurizing chamber 3. A piezoelectric actuator 21 is stacked on the flow path member 4 so as to cover the plurality of liquid pressurizing chambers 3. A common electrode 23 a is provided inside the piezoelectric actuator 21, and the surface of the piezoelectric actuator 21 opposite to the surface joined to the flow path member 4 corresponds to the liquid pressurizing chamber 3, and a plurality of drive electrodes 23 b are provided. Is provided. The drive electrode 23b can be provided at 100 pieces / cm ² or more. The piezoelectric actuator 21 includes a piezoelectric ceramic layer 21 a sandwiched between the drive electrode 23 b and the common electrode 23 a and a piezoelectric ceramic layer 21 a joined to the flow path member 4. The piezoelectric ceramic layer 21a functions as a diaphragm.

  The connection electrode 23c is drawn from the drive electrode 23b to a position where the liquid pressurizing chamber 3 is not located immediately below the connection electrode 23c.

  The piezoelectric ceramic layer 21a, the common electrode 23a, the piezoelectric ceramic layer 21b, and the drive electrode 23b immediately above each liquid pressurizing chamber 3 constitute a displacement element 11 as a whole, and the displacement element 11 is a liquid pressurizing means.

  In such a liquid discharge head 1, by applying a drive voltage from an external circuit (not shown) to the drive electrode 23b via the connection electrode 23c, the displacement element 11 in the piezoelectric actuator 21 is displaced by this drive voltage. Then, the liquid in the liquid pressurizing chamber 3 is pressurized, and droplets are ejected from the nozzle hole 2.

  The matrix arrangement of the liquid pressurizing chambers 3 may be other two-dimensional and regular arrangements such as a lattice arrangement in addition to the zigzag arrangement shown in the figure. The staggered arrangement is preferable in order to reduce the crosstalk because the distance between the liquid pressurizing chambers 3 can be increased.

  The nozzle plate 4 a has a water repellent layer 8 formed on one main surface of a plate 7 having a plurality of nozzle holes 2. The water repellent layer 8 has holes 9 connected to the plurality of nozzle holes 2. A water repellent resin film 10 is formed on the front surface of the water repellent layer 8 and the wall surface of the hole 9 formed in the water repellent layer connected to the nozzle 2. The film thickness of the water repellent resin film 10 is 100 to 300 nm.

  The size of the nozzle hole 2 is preferably 18 to 24 μm in order to obtain an appropriate droplet amount and droplet discharge speed, and the thickness of the plate 7 is preferably 20 to 70 μm. If the thickness is 20 μm or less, it is difficult to handle the nozzle plate 4a itself because it is fragile in the manufacturing process, etc., and the pressure propagation in the nozzle hole 2 varies, making it difficult to obtain straightness in the discharge direction of the droplets. is there. On the other hand, if it is 70 μm or more, the resistance on the inner wall surface of the nozzle 2 is increased, and the discharge speed may be reduced.

  The thickness of the water repellent layer 8 is preferably 0.5 to 3 μm. If the thickness is 0.5 μm or less, it is difficult to stably form the density of the water-repellent resin in the plating layer, and even if 3 μm or more is applied, the characteristics of the water-repellent film do not change so much. It will be in vain. Further, since the thickness is large, stress remains in the water-repellent layer 8 formed by plating, and the nozzle plate 4a is warped.

  In such a liquid discharge head 1, an interface (meniscus) between the liquid and air (external gas) is formed inside the nozzle hole 2, and the end of the meniscus is in a state where no pressure is applied, It is located at the boundary between the plate 7 and the water repellent layer 8 in the nozzle hole 2. When the liquid in the liquid pressurizing chamber 3 is pressurized by the displacement element 11, the meniscus swells outside the liquid discharge head 1, tears off, and then flies as a droplet, land on a recording medium such as paper, and record. Can leave. At this time, if the water repellency of the water repellent layer 8 is not sufficient, the liquid is difficult to peel off from the water repellent layer 8, so that the liquid ejection characteristics are changed. The liquid ejection characteristics are specifically the flying direction and flying speed of the droplets. If the liquid ejection characteristics change, the landing position of the droplet on the recording medium is displaced, which may result in insufficient recording accuracy.

  Further, even if the water-repellent layer 8 has sufficient water repellency, the liquid ejection characteristics change even if the nozzle hole 2 has a minute shape difference. For example, the size of the nozzle hole 2 where the meniscus is formed, the shape of the water-repellent layer 8, the hole shape of the nozzle hole 2 viewed from the main surface, and the like. The shape of the water repellent layer 8 has a shape of a hole 9 connected to the nozzle hole 2 formed in the water repellent layer 8 (on the main surface of the nozzle plate 4a) in order to reduce the influence on the droplets flying away from the meniscus. The shape as viewed from the vertical direction) is preferably similar to the shape of the nozzle hole 2 at the boundary between the plate 7 and the water-repellent layer 8 in the nozzle hole 2 where the meniscus is formed, and is preferably the same size or larger. . Due to the similar shape, the droplet is less likely to receive a force from a specific direction of the hole 9. When the size is the same or larger, the droplet is unlikely to receive an extra force unlike a narrow hole.

For example, when the shape of the nozzle hole 2 and the hole 9 is a circle, the diameter r ₁ on the nozzle hole 2 side of the hole 9 and the diameter r ₂ on the opposite side of the nozzle hole 2 are the plates in the nozzle hole 2 where the meniscus is formed. it is preferable equal to or greater than 7 and the diameter r _N of the nozzle hole 2 of the boundary of the water-repellent layer 8.

Further, in order to reduce the influence on the droplets flying away from the meniscus, the hole 9 formed in the water repellent layer 8 has an opening diameter on the side opposite to the nozzle hole 2 larger than the opening diameter on the nozzle hole 2 side. Is preferred. For example, when the shape of the nozzle hole 2 and the hole 9 is a circle, it is more preferable that the diameter r ₂ on the opposite side of the nozzle hole 2 is larger than the diameter r _{1 of the} hole 9 on the nozzle hole 2 side. Further, it is preferable that the hole 9 of the water repellent layer 8 and the front surface of the water repellent layer 8 are connected by a smooth curve rather than a corner.

  Furthermore, when the nozzle hole 2 is formed by punching or the like, the opening diameter of the nozzle hole 2 gradually decreases from the main surface into which the punching die is inserted toward the other main surface. The variation in the shape of the nozzle hole viewed from the direction perpendicular to the main surface of the plate 7 of the hole 2 can be reduced. For example, when the design shape of the nozzle hole 2 is a circle, the shape is closer to a perfect circle, and variations in liquid ejection characteristics due to the hole shape can be reduced.

  Although the liquid discharge head and the nozzle plate have been described above, the liquid discharge head and the nozzle plate of the present invention are not limited to the above-described embodiment. In particular, for the liquid ejection head, the liquid pressurizing chamber may be a metal press-molded one, a resin injection-molded one, or the like. The same applies to the pressurizing means, and another piezoelectric method or a thermal method in which the liquid is boiled by the heat generated by the heater and a droplet is discharged by the generated bubbles may be used.

  Next, a method for manufacturing the nozzle plate will be described. 2 (a) to 2 (g) are partial cross-sectional views of the plate in each step of the manufacturing process according to one embodiment of the present invention. The steps are performed in the order of FIG. 2 (a) to FIG. 2 (g). move on.

  First, the plate 101 is prepared. Examples of the raw material for the plate 101 include metal materials such as stainless steel plates, aluminum plates, and molybdenum plates, semiconductor materials such as silicon, ceramic materials such as alumina and silicon carbide, and the like. It is preferable to use a metal material that can be precisely processed. For example, it is desirable to be formed of at least one selected from the group consisting of an alloy mainly composed of Fe and Cr, an alloy mainly composed of Fe and Ni, and an alloy mainly composed of WC and TiC. . In particular, in applications where ink is ejected, it is desirable to be made of a material having excellent corrosion resistance against ink, and an alloy containing Fe and Cr as main components is more preferable.

  In the following description of the steps, when the water repellent layer is finally formed and incorporated in the liquid discharge head, the main surface facing the outside of the liquid discharge head is the front surface, and the opposite main surface Is referred to as the back side.

  First, as step A, nozzle holes 102 penetrating between the main surfaces of the plate 101 are formed. FIG. 2A shows the plate 101 after the process A is completed. The nozzle hole 102 can be formed by a method such as punching using a mold, etching, or drilling. Punching with a mold is a preferable forming method in that the cost can be reduced. In the case of punching with a mold, in order to form a stable shape when viewed from a direction perpendicular to the main surface of the plate 101 of the nozzle hole 102, the nozzle hole 102 is formed from the main surface on the side where the mold enters. It is preferable to punch into a shape that gradually decreases toward the opposite main surface. Further, in order to stabilize the shape, it is preferable that after the punching is finished, the convex part on the punched side is polished and flattened.

  Next, as a process B, a photocurable resin is supplied to one main surface of the plate so as to fill a part of one main surface side of the nozzle hole 102 to form a photocurable resin film 103. FIG. 2B shows the plate 101 after the process B is completed. In FIG. 2B, a film-like photocurable resin film 103 is attached to the front surface of the plate 101, and the photocurable resin film 103 is heated and pressed to soften the photocurable resin film 103. Part of the nozzle hole 102 was filled into part of one main surface side. It is preferable not to fill the nozzle hole 102 until it reaches the back surface. By doing so, it becomes easy to mask in the plating process described later, and it becomes easy to remove the photocurable resin film 103 after curing. Further, the photocurable resin film 103 may be formed by applying a resin whose viscosity has been lowered by heating, or by applying a photocurable resin film 103 mixed with a solvent and drying it. .

  The supply of the photocurable resin film 103 may be performed from the back side. In that case, the photocurable resin film 103 is filled until it reaches the front surface. The photocurable resin film 103 is preferably supplied from the front surface because the amount and shape of the photocurable resin film 103 on the front surface are stabilized.

  Next, as a process C, light is irradiated from the back side of the plate 101 to cure a part of the photocurable resin film 103. FIG. 2C shows the plate 101 in the process C. The photocurable resin film 103 in the nozzle hole 102 and the photocurable resin 103 immediately above the nozzle hole 102 are cured by the irradiated light. The photocurable resin film 103 that is cured at this time has the same shape as the front surface of the nozzle hole 102. By extending the curing time at this time, the curing range of the photocurable resin film 103 in the vicinity of the nozzle hole 102 can be made wider on the side not in contact with the plate 101 than on the side in contact with the plate 101. If you do this. Since the opening diameter of the hole formed in the plating film 104 on the side opposite to the nozzle hole 102 can be made larger than the opening diameter on the nozzle hole 102 side, it is preferable.

  Next, as a process D, a development process for removing an uncured portion of the photocurable resin film 103 from the plate 101 is performed. FIG. 2D shows the plate 101 after the process D is completed. The uncured photocurable resin film is removed, and the cured photocurable resin film 103-1 remains in a columnar shape in the same shape as the front surface of the nozzle hole 102 in the nozzle hole 102 and immediately above the nozzle hole 102. The development process is performed with a developer that dissolves an uncured photocurable resin. The developer is, for example, an alkaline aqueous solution. The development process is performed by spraying a developer on the plate 101 or immersing the plate 101 in a tank filled with the developer.

  Next, as step E, a plating layer 104 containing particles of the water repellent resin 106 is formed on the front surface of the plate 101. FIG. 2E shows the plate 101 after the process E, and FIG. 3A is an enlarged partial cross-sectional view of a portion A in FIG. In FIG. 3A, the cured photocurable resin 103-1 is omitted. The plating layer 104 contains particles of a metal 105 and a water repellent resin 106. The metal 105 is, for example, nickel, and the water repellent resin 106 is a fluorine-based polymer resin, for example, polytetrafluoroethylene. For example, the plated layer 104 disperses the particles of the water-repellent resin 106 in a plating tank for plating the metal 105 so that the particles of the water-repellent resin 106 adhere to the metal 105 while the metal 105 is deposited. Formed. During plating, portions such as the back surface of the plate where the plating layer 104 is not formed may be masked.

  When forming the plating layer, as shown in FIG. 4, the content of the water repellent resin 206 in the plate 101 side region of the plating layer 204 is set to the water repellent resin 206 in the front surface region of the plating layer 104. It may be higher than the content of. In FIG. 4, the content of the water-repellent resin 206 in the plating layer 204 d is higher than the plating layer 204 e on the surface side of the plating layer 204. For example, the plating layer 204 can be formed by changing the amount of the water-repellent resin 206 particles dispersed in the plating tank or changing the plating conditions while plating the plating layer 204. It can be formed by changing the amount of formation. In such a plated layer 204, the particles of the water repellent resin 206 are more exposed at the inner wall 204b of the plated layer hole connected to the inner wall of the nozzle hole 102, particularly at the end of the plated layer 204 in the nozzle hole 102 where the meniscus is formed. In addition, the water repellent resin can be formed more reliably.

  Further, when forming the plating layer, as shown in FIG. 5, the content of the water-repellent resin 306 in the plating layer 304 in the region immediately above the nozzle hole 102 is determined based on the content of the water-repellent resin 306 in the outer region. It can be high. In FIG. 5, the content of the water repellent resin 306 in the plating layer 304f around the nozzle hole 102 in the plating layer 304 is higher than the content of the water repellent resin 306 in the outer plating layer 304g. Such a plating layer 304 can be formed, for example, by causing the particles of the water-repellent resin 306 to stay around the cured photocurable resin 103-1, by slowing the circulation rate of the plating solution in the plating tank. . In such a plated layer 304, particles of the water-repellent resin 306 are more exposed on the inner wall of the hole 304b of the plated layer connected to the inner wall of the nozzle hole 102, and the water-repellent resin can be more reliably formed.

  Next, as the process F, the cured photocurable resin film 103-1 is removed from the plate 101 on which the plating layer 104 is formed. FIG. 2F shows the plate 101 after the process F. The removal is performed by immersing the plate 101 in a stripping solution or by applying a stripping solution to the plate 101. The stripping solution dissolves the surface of the cured photocurable resin film 103-1, enters between the cured photocurable resin film 103-1 and the plate 101, and removes the cured photocurable resin film 103-1. remove. As the stripping solution, one corresponding to the type of the photocurable resin film 103, for example, a sodium hydroxide solution is used.

  Next, as a process G, the plating layer 104 of the plate 101 is etched. FIG. 2G shows the plate 101 after the process G, and FIG. 3B is an enlarged partial cross-sectional view of a portion B of FIG. Etching is performed by immersing the plate 101 in an etching solution. The etching solution etches the metal 105 in the plating layer 104 and exposes the particles of the water repellent resin 106 to the surface of the plating layer 104. In particular, since the inner wall surface 104b of the hole formed in the plating layer 104 connected to the nozzle hole 102 was in contact with the cured photocurable resin film 103-1, when the plating layer 104 was formed, the exposed water-repellent resin 106 was exposed. However, by etching, the water-repellent resin 106 particles can be exposed to the same extent as the front surface 104a of the plating layer 104. As the etching solution, an acid solution such as nitric acid with respect to nickel is used according to the type of the metal 105.

  Further, by adjusting the etching conditions such as increasing the etching amount, the boundary 104c between the front surface 104a of the plating layer 104 and the inner wall surface 104b of the hole formed in the plating layer 104 connected to the nozzle hole 102 is rounded, The hole formed in the plating layer 104 connected to the nozzle hole 102 can have an opening diameter on the side opposite to the nozzle hole 102 larger than the opening diameter on the nozzle hole 102 side. By adopting such a shape, variation when the liquid is separated from the water repellent layer 104-1 at the end of the nozzle hole 102 when used in a liquid ejection head is reduced, and variation in liquid ejection characteristics can be reduced.

  Next, in step H, heat is applied to the plated layer 104 of the etched plate 101 to expose the surface 104a of the plated layer 104 and the wall surface 104b of the hole formed in the plated layer 104 connected to the nozzle 102. Resin 106 is softened. The water repellent resin 106 is softened and spreads on the surface of the plating layer 104 to form a water repellent resin film of the water repellent resin 106. Thus, the plating layer 104 becomes a water-repellent layer in which the water-repellent resin film of the water-repellent resin 106 is formed on the surface (the wall surface of the hole formed in the water-repellent layer connected to the front surface and the nozzle 102). .

  Step F and step G may be performed in the reverse order. That is, after step E, an etching step is performed as step I, a step of removing the cured photosensitive resin film 103-1 is thereafter performed as step J, and a step of softening the water-repellent resin 106 is further performed as step K. You can do it. The conditions of each process may be the same as the above-mentioned same process. In the etching process, the etching solution enters between the plating layer 104 and the cured photosensitive resin film 103-1, and etching is performed.

  A liquid discharge head using the nozzle plate for a liquid discharge head prepared as described above is manufactured as follows, for example. Here, an example in which the liquid discharge head shown in FIG.

  A tape made of a piezoelectric ceramic and an organic composition is formed by a general tape forming method such as a roll coater method or a slit coater method, and a plurality of green sheets that become the piezoelectric ceramic layers 21a and 21b after firing are produced. An electrode paste to be the common electrode 23a is formed on a part of the green sheet by a printing method or the like. Further, if necessary, a via hole is formed in a part of the green sheet, and a via conductor is inserted into the via hole.

  Next, each green sheet is laminated to produce a laminate, and pressure adhesion is performed. After firing the pressure-bonded laminate in a high-concentration oxygen atmosphere, the drive electrode 23b is printed on the surface of the fired body using an organic gold paste and fired, and then the connection electrode 23c is printed using an Ag paste. The piezoelectric actuator 21 is produced by firing.

  Next, the flow path member 4 is obtained by laminating plates 4a to 4i obtained by a rolling method or the like. The plate 4a is a nozzle plate manufactured by the above-described manufacturing method, and the plates 4b to 4i are processed into a predetermined shape by etching so that the liquid pressurizing chamber 3 and the liquid flow path 5 are formed.

  These plates 4a to 4i are preferably formed of at least one metal selected from the group of Fe—Cr, Fe—Ni, and WC—TiC, particularly when ink is used as a liquid. Since it is desired to be made of a material having excellent corrosion resistance against ink, Fe-Cr is more preferable.

  The piezoelectric actuator 21 and the flow path member 4 can be laminated and bonded via an adhesive layer, for example. A well-known adhesive layer can be used as the adhesive layer. However, in order not to affect the piezoelectric actuator 21 and the flow path member 4, an epoxy resin, a phenol resin, or a polyphenylene ether having a thermosetting temperature of 100 to 150 ° C. It is preferable to use at least one thermosetting resin adhesive selected from the group of resins. By heating to the thermosetting temperature using such an adhesive layer, the piezoelectric actuator 21 and the flow path member 4 can be heat-bonded.

  Thereafter, in order to electrically connect the piezoelectric actuator upper 21 and an external circuit as necessary, a flexible flat cable or the like is joined to the connection electrode 23c to obtain a liquid discharge head.

The liquid discharge head shown in FIGS. 1A to 1C was manufactured. That is, a PbZrTiO ₃ system powder having an average particle size of 0.5 μm is mixed with a binder and an organic solvent to prepare a slurry of a piezoelectric material, and then a green having a thickness of 30 μm is formed by a roll coater method using the obtained slurry. A sheet was produced.

  On the other hand, Ag—Pd powder was blended so that the mixing ratio was Ag: Pd = 7: 3, and a predetermined amount of an organic binder and a solvent was mixed to prepare a conductive paste.

  Next, the green sheet coated with the conductive paste and the green sheet not coated with the electrode paste are laminated, heat is applied to form a mother laminate, and the mother laminate is cut and laminated. A body was formed and baked by holding at 1000 ° C. for 2 hours in an oxygen atmosphere to form a piezoelectric actuator body.

  Next, a metal paste mainly composed of Au was screen-printed on one surface of the piezoelectric actuator body and baked at 750 ° C. to form the drive electrode 23b.

  Further, a metal paste mainly composed of Ag was screen-printed and baked at 600 ° C. to form a connection electrode 23b that is electrically connected to an external circuit, thereby completing the piezoelectric actuator 21.

  Next, the Fe—Cr alloy was formed to a thickness of 30 μm by a rolling method, punched to a predetermined size, and a plate 101 was manufactured. A plurality of nozzle holes 102 were formed by punching with a mold from the back surface. The shape of the nozzle hole 102 was a circle having a diameter of 20 μm on the back surface side and a diameter of 40 μm on the front surface side, and the inner wall between them was formed by straight lines. The front side was flattened by polishing after punching.

  Next, a film-like photocurable resin film 103 is attached to the front surface of the plate 101, and heat and pressure are applied to the photocurable resin film 103, and a part of the softened photocurable resin film 103 is applied. Part of the nozzle hole 102 was filled.

  Next, light is irradiated from the back side of the plate 101, and the columnar photocurable resin 103 having the same cross-sectional shape as the front surface of the photocurable resin 103 in the nozzle hole 102 and the nozzle hole 102 immediately above the nozzle hole 102 is applied. Cured.

  Next, an alkaline aqueous solution was sprayed onto the plate 101 to remove an uncured portion of the photocurable resin film 103 and develop.

  Next, after masking the back surface of the plate 101 so as not to be plated, the plate 101 is placed in a plating solution in which particles having an average particle diameter of 0.2 μm of polytetrafluoroethylene, which is a water repellent resin, are dispersed. A plating layer 104 having a thickness of 1 μm containing metal 105 and polytetrafluoroethylene particles was formed on the front surface.

  Next, the plate 101 was placed in a 2% sodium hydroxide solution as a stripping solution, and the cured photocurable resin film 103-1 was removed.

  Next, the plating layer 104 of the plate 101 was etched with a 2% nitric acid solution.

  Next, the plate 101 is placed in an oven and heated at 350 ° C. for 30 minutes to soften the polytetrafluoroethylene, which is a water-repellent resin, on the front surface of the plating layer 104, and a water-repellent resin film of polytetrafluoroethylene. To obtain a nozzle plate 4a.

  Next, the Fe—Cr alloy was formed into a plate shape by a rolling method, and processed into a predetermined shape by etching so that the liquid pressurizing chamber 3 and the liquid flow path 5 could be formed, and the plates 4b to 4i were manufactured. The plates 4a to 4i were joined with an epoxy resin to produce the flow path member 4, and the piezoelectric actuator 21 was further joined with an epoxy adhesive to produce a liquid ejection head (liquid ejection head No. 1).

  Further, the plating tank in which plating is performed during the formation of the plating layer is changed, and the content of the water-repellent resin on the plate side of the plating layer is changed to the content of the water-repellent resin on the surface side of the plating layer as shown in FIG. A liquid discharge head was manufactured using a higher nozzle plate (liquid discharge head No. 2).

  Further, the stirring condition of the plating solution in the plating tank for plating is changed, the circulation rate of the plating solution is lowered, and the content of the water-repellent resin particles in the plating layer around the nozzle hole as shown in FIG. A liquid discharge head was manufactured using a nozzle plate having a higher content of the water-repellent resin particles on the outer side (liquid discharge head No. 3).

  Further, as shown in FIG. 3B, a liquid discharge head is manufactured by using a nozzle plate having an opening diameter on the side opposite to the nozzle hole larger than the opening diameter on the nozzle hole side of the hole, as shown in FIG. (Liquid discharge head No. 4).

  Further, a liquid discharge head was manufactured using a nozzle plate that was not subjected to the etching process (liquid discharge head No. 5).

  The thickness of the water-repellent film on each nozzle plate was measured using Auger electron spectroscopy. At this time, the film thickness was defined as the distribution thickness of fluorine distributed in a film shape on the surface.

  The thickness of the water repellent film on the inner wall of the hole connected to the nozzle hole formed in the water repellent layer of each nozzle plate was as follows. Liquid discharge head No. 1 is 100 nm, the liquid discharge head No. 2 is 150 nm on the nozzle hole side, and 100 nm is on the opposite side of the nozzle hole. 3 is 150 nm, the liquid discharge head No. 4 is 100 nm, the liquid ejection head No. 5 was 50 nm.

  The thickness of the water-repellent film on the main surface of each nozzle plate was 100 nm in any nozzle plate. However, the liquid discharge head No. In No. 3, the vicinity of the nozzle holes was 150 nm, and between the nozzle holes was 100 nm.

  Liquid discharge head No. 1 using the nozzle plate of the present invention. 1-4 showed the favorable discharge characteristic with few dispersion | variations for every nozzle hole. In particular, the liquid discharge head no. No. 4 had less variation.

  In addition, the liquid discharge head No. The water repellent resin film having two nozzle holes is formed to be thicker at the 204d portion than the 204e portion in FIG. 4, and the manufacturing conditions of the nozzle plate vary, and the water repellent layer deteriorates when the liquid discharge head is used. It is considered that the water repellency of the water-repellent resin film is maintained even when the water is generated.

  In addition, the liquid discharge head No. The water repellent resin film having three nozzle holes is formed so that the portion 304a is thicker than the portion 304b in FIG. 5, and the manufacturing conditions of the nozzle plate vary, and when the liquid discharge head is used, the water repellent resin film It is considered that the water repellency of the water repellent layer is maintained even when deterioration occurs.

  On the other hand, the liquid discharge head No. which does not use the nozzle plate of the present invention. No. 5 had nozzle holes that varied in discharge, and the formation of the water-repellent resin film was insufficient.

(A) It is a partial longitudinal cross-sectional view of one Embodiment of the liquid discharge head of this invention. FIG. 4B is a top view of the liquid discharge head. (C) It is a partial expanded sectional view of the nozzle hole vicinity of the nozzle plate of this invention. It is a fragmentary longitudinal cross-sectional view in each process which shows one Embodiment of the manufacturing method of the nozzle plate of this invention. It is a fragmentary longitudinal cross-sectional view of the nozzle plate which shows the detail of the etching process of FIG.2 (g). It is a fragmentary longitudinal cross-sectional view of the nozzle plate after the plating process in other embodiment of the manufacturing method of the nozzle plate of this invention. It is a fragmentary longitudinal cross-sectional view of the nozzle plate after the plating process in other embodiment of the manufacturing method of the nozzle plate of this invention. It is the fragmentary longitudinal cross-sectional view of the nozzle plate after the plating process in the manufacturing method of the nozzle plate of a reference example. It is a fragmentary longitudinal cross-sectional view of the nozzle plate after the plating process in the manufacturing method of the nozzle plate of another reference example. It is a fragmentary longitudinal cross-sectional view of the nozzle plate in each process which shows the manufacturing method of the conventional nozzle plate. It is a fragmentary longitudinal cross-sectional view of the nozzle plate in each process which shows the manufacturing method of the other conventional nozzle plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid discharge head 2 ... Nozzle hole 3 ... Ink pressurization chamber 4 ... Flow path member 4a ... Liquid discharge head nozzle plates 4b-4i ... Plate 5 ... Liquid Channel 7 ... Plate 8 ... Water-repellent layer (plating layer)
9 ... hole 10 ... water-repellent resin film 11 ... ink pressurizing means 21 ... piezoelectric actuator 21a ... piezoelectric ceramic layer (vibrating plate)
21b: Piezoelectric ceramic layer (piezoelectric layer)
23a ... Common electrode 23b ... Drive electrode 23c ... Connection electrode 101 ... Plate 102 ... Nozzle hole 103 ... Photosensitive resin film 103-1 ... Cured photosensitive resin film 104 , 204, 304... Plating layers 104a, 204a, 304a... Plate surface 104b, 204b, 304b... Inner wall surface 104c of the hole formed in the plating layer connected to the nozzle hole ... Boundary between the plating layer surface on the plate front side and the inner wall surface of the hole formed in the plating layer connected to the nozzle hole

Claims (9)

  Forming a nozzle hole penetrating between the principal surfaces of the plates, and supplying a photocurable resin to one principal surface of the plate so as to fill a part of one principal surface side of the nozzle holes; A step B of forming a photocurable resin film, and one of the photocurable resin films including the photocurable resin film filled with the nozzle holes by irradiating light from the other main surface side of the plate A step C for curing the portion; a step D for removing the uncured photocurable resin film from the plate; and one main surface of the plate from which the uncured photocurable resin film has been removed. Step E for forming a plating layer containing resin particles, Step F for removing the cured photocurable resin film from the plate on which the plated layer is formed, and removal of the cured photocurable resin film Etching the plated layer of the plate And a step H for softening the particles of the water-repellent resin exposed to the surface of the plating layer by applying heat to the plating layer of the plate on which the plating layer has been etched. Manufacturing method of head nozzle plate.   Forming a nozzle hole penetrating between the principal surfaces of the plates, and supplying a photocurable resin to one principal surface of the plate so as to fill a part of one principal surface side of the nozzle holes; , A step B of forming a photocurable resin film, a step C of irradiating light from the other main surface side of the plate to cure a part of the photocurable resin film, and the uncured from the plate Step D for removing the photocurable resin film, Step E for forming a plating layer containing water-repellent resin particles on one main surface of the plate from which the uncured photocurable resin film has been removed, Step I of etching the plating layer of the plate with the cured photocurable resin film, Step J of removing the photocurable resin film cured from the plate with the plated layer etched, and curing The photocurable resin film was removed The method of manufacturing a nozzle plate for a liquid discharge head which comprises a step K to soften the particles of water-repellent resin exposed to the plating layer by applying heat the plating layer surface to the serial plate.   3. The liquid ejection head according to claim 1, wherein, in the step C, the curing range of the photocurable resin film in the vicinity of the nozzle hole is widened on the side not in contact with the plate rather than on the side in contact with the plate. Manufacturing method of nozzle plate.   In the step E, the content of the water-repellent resin contained in the plate-side region of the plating layer is made higher than the content of the water-repellent resin contained in the surface-side region of the plating layer. The manufacturing method of the nozzle plate for liquid discharge heads in any one of Claim 1 to 3.   The content rate of the water-repellent resin contained in the region immediately above the nozzle hole of the plating layer is made higher than the content rate of the water-repellent resin contained in the outer region in the step E. Item 5. A method for producing a nozzle plate for a liquid discharge head according to any one of Items 1 to 4.   A liquid having a plate having nozzle holes and a water repellent layer having a water repellent resin film formed on one surface of the plate and having holes connected to the nozzle holes. A nozzle plate for a liquid discharge head, wherein the hole has a shape similar to the shape of the nozzle hole and is the same size or larger than the nozzle hole.   The nozzle plate for a liquid discharge head according to claim 6, wherein the hole has an opening diameter on the side opposite to the nozzle hole that is larger than an opening diameter on the nozzle hole side.   8. The nozzle plate for a liquid discharge head according to claim 6, wherein the nozzle hole is gradually increased from one main surface to the other main surface of the plate.   The nozzle plate for a liquid discharge head according to any one of claims 6 to 8, a liquid pressurization chamber connected to the nozzle hole of the nozzle plate for the liquid discharge head, and pressurization for pressurizing the liquid in the liquid pressurization chamber Means. A liquid discharge head comprising: means.

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