JP4163075B2 - Nozzle plate manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a nozzle plate used in a fine dot forming apparatus for forming a fine pattern with fine dots.

  In the past, ink jet printers have been exclusively used as printers, literally on paper. However, in recent years, focusing on the versatility and low cost of inkjet printer technology, the formation of fine patterns such as color filters for liquid crystal display devices and the formation of conductor patterns on printed wiring boards, which have been processed by conventional photolithography technology. Inkjet printers are attracting attention for such applications. Therefore, in recent years, there has been a development of a micro dot forming apparatus capable of forming a micro pattern with high accuracy by directly drawing micro ink dots on a drawing target (for example, a color filter for liquid crystal display or a printed wiring board). It is active.

  In such a minute dot forming apparatus, a nozzle plate having high discharge characteristics such as discharge stability and high landing accuracy is required.

  The structure and manufacturing method of the conventional nozzle plate will be described below. Patent Document 1 discloses a technique for forming a nozzle plate by dry etching and wet etching. FIGS. 11A and 11B are explanatory diagrams of the nozzle plate described in Patent Document 1 (hereinafter referred to as a conventional configuration).

The conventional nozzle plate is composed of an SOI (Silicon on Insulator) substrate 21. As shown in FIGS. 11A and 11B, the SOI substrate 21 has an SiO ₂ layer 26 that is an etching stop layer over the entire area of the Si layer 25 that is a support, and further on the SiO ₂ layer 26. It has a Si layer 24 which is an active layer. An orifice 22 is formed in the Si layer 24, and a tapered portion 23 is formed in the Si layer 25. The orifice 22 and the tapered portion 23 are communicated with each other.

A conventional nozzle plate manufacturing method (hereinafter referred to as a conventional method) is as follows. First, the surface of the Si layer 24 which is an active layer is oxidized to form an oxide film (not shown). Then, a predetermined pattern is formed on the oxide film 28, dry etching is performed using this pattern as a mask, and etching is stopped with the SiO ₂ layer 26 which is an etching stop layer to form the orifice 22. Next, the surface of the Si layer 25 as a support layer is oxidized to form an oxide film (not shown). A predetermined pattern is formed on this oxide film, and dry etching is performed under the conditions that cause undercut using this pattern as a mask, and the etching is stopped with the SiO ₂ layer 26 to form the tapered portion 23. Finally, the SiO ₂ layer 26 and the oxide film on the surface between the orifice 22 and the tapered portion 23 are removed with a hydrofluoric acid-based etching solution.
JP-A-9-216368 (Publication date: August 19, 1997)

  However, the conventional configuration has the following problems.

  In this reference, an SOI substrate is used and the shape of the droplet discharge portion is processed by dry etching. However, the processing accuracy is described as ± 1 μm, and the processing accuracy is low for application to a fine dot forming apparatus. Further, in this example, the etching on the ink inflow side is performed under the condition that causes an undercut, and the ink inflow side is tapered. At this time, since the thickness on the ink inflow side is 100 μm, the ink inlet is increased to several tens of μm. As a result, there is a problem in that the integration degree of the nozzles is lowered and the drawing resolution is not improved.

  As a measure for improving processing accuracy and nozzle integration (not described in the reference), a method of reducing the etching amount of the ink discharge port and the etching amount of the ink inlet is conceivable. That is, if the etching amount is reduced, the processing variation and undercut are reduced accordingly, so that the processing accuracy is improved in principle and the degree of integration is also improved.

  In this example, since the discharge side nozzle hole and the inflow side nozzle hole are processed by etching penetrating the substrate, it is necessary to reduce the thickness of the SOI substrate in order to reduce the etching amount. However, if the thickness of the substrate is reduced in this reference, the rigidity of the substrate itself is lowered, and there is a problem that the shape accuracy is greatly lowered when a mask pattern for determining an etching shape is generated due to the deformation of the substrate.

  Furthermore, in this example, the discharge-side nozzle hole and the inflow-side nozzle hole are formed by etching from both sides of the substrate, so that the discharge-side nozzle hole is formed or flows into the formed part. There is a high risk that scratches such as scratches are imparted in a series of steps of mask pattern formation, etching, cleaning, and mask pattern removal for processing the nozzle hole on the side. In a multi-nozzle plate having a large number of nozzle holes, even if any one of the nozzle holes is damaged, it cannot be used as a nozzle plate. That is, the nozzle plate manufacturing method of the present reference has a problem that a multi-nozzle nozzle plate having a large number of nozzle holes cannot be manufactured stably.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a first nozzle hole with high formation accuracy and to stably provide a plurality of nozzle discharge processes without causing damage to droplet discharge ports. It is an object of the present invention to provide a method for manufacturing a nozzle plate that can produce a nozzle plate having a plurality of droplet discharge ports.

  In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention is a method for manufacturing a nozzle plate having at least one nozzle hole for discharging a liquid substance, the step of preparing a sacrificial member, and the sacrifice Forming a first nozzle layer on the member; processing a nozzle hole in the first nozzle layer; and etching the sacrificial member after the nozzle hole processing to form the first nozzle layer and the sacrificial member. It is characterized by comprising a step of separating.

  In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention is the above-described manufacturing method of a plate, wherein the sacrificial member includes a substrate and a layered member formed on the substrate. It is a feature.

  In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention is the first nozzle plate manufacturing method according to the first nozzle hole etching method on the first nozzle layer. The first nozzle hole is etched using the step of forming a shielding layer having higher etching resistance than the nozzle layer, the step of forming a through hole in the shielding layer, and the shape of the through hole formed in the shielding layer as a mask. A step of etching the first nozzle hole and then etching the sacrificial member to separate the first nozzle layer from the sacrificial member.

  In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention includes a first nozzle hole and a nozzle hole formed on the first nozzle layer in the step of forming a shielding layer in the nozzle plate manufacturing method. A first nozzle layer and a shielding layer having higher etching resistance than the second nozzle layer are formed on the etching processing means of the second nozzle hole, and the shielding layer is formed on the shielding layer and on the first nozzle layer. A step of forming a second nozzle layer on a portion where no is formed, and a step of forming, by etching, a second nozzle hole reaching the shielding layer from the surface of the second nozzle layer in the second nozzle layer. The first nozzle layer and the sacrificial member are separated from each other by etching the sacrificial member after etching the first nozzle hole and the second nozzle hole. There.

  In order to solve the above problems, a method for manufacturing a nozzle plate according to the present invention includes a step of etching the second nozzle hole in the method for manufacturing a nozzle plate, and an etching process for the first nozzle hole. The step of performing is performed continuously in this order by the same etching apparatus.

  In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention is the above-described nozzle plate manufacturing method, on the shielding layer and on a portion where a shielding layer is not formed on the first nozzle layer. And a step of bonding a reinforcing plate, and after the reinforcing plate is bonded, the sacrificial member is etched to separate the first nozzle layer and the sacrificial member.

  In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention is characterized in that the sacrificial member is etched using an acid or an alkaline solution in the nozzle plate manufacturing method.

In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention provides a sacrificial member at least partially made of a material mainly composed of Ni, Cu, or Al in the above-described nozzle plate manufacturing method. A step, a step of forming a first nozzle layer or a second nozzle layer made of polyimide or a material mainly containing at least one of Si, SiO ₂ , and Si ₃ N ₄ , Ti, W, _{nb, Au, Pt, SiO 2} , Si 3 N 4, a step of forming a shielding layer mainly one or more of the Al ₂ O _3, the sacrificial member with an aqueous solution containing nitric acid or potassium hydroxide And a step of etching.

  In order to solve the above-described problems, a method for manufacturing a nozzle plate according to the present invention is characterized in that the sacrificial member is etched using plasma containing oxygen in the method for manufacturing a nozzle plate.

In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention includes a step of preparing a sacrificial member made of a material mainly composed of polyimide in at least a part of the nozzle plate manufacturing method, and Si , Forming a first nozzle layer or a second nozzle layer made of a material mainly containing at least one of SiO ₂ and Si ₃ N ₄ , Al, Cu, Ni, Fe, Co, The method includes a step of forming a shielding layer mainly composed of one or more of Au, Pt, and Al ₂ O ₃ and a step of etching the sacrificial member using oxygen-containing plasma. .

  In order to solve the above-described problem, the nozzle plate manufacturing method according to the present invention performs the outer shape processing of the nozzle plate simultaneously with the first nozzle hole processing in the nozzle plate manufacturing method. It is a feature.

  In order to solve the above-described problem, the nozzle plate manufacturing method according to the present invention includes performing the outer shape processing of the nozzle plate simultaneously with the second nozzle hole processing in the nozzle plate manufacturing method. It is a feature.

  As described above, the method for manufacturing a nozzle plate according to the present invention includes a step of forming a sacrificial member, a step of forming a first nozzle layer on the sacrificial member, and a nozzle hole in the first nozzle layer. Since the first nozzle layer is formed on the sacrificial member, the step of etching and the step of etching the sacrificial member after the nozzle hole processing to separate the first nozzle layer and the sacrificial member are provided. High rigidity and low deformation of workpiece in plate manufacturing process. For this reason, since the formation precision of the mask pattern which has the shape of the nozzle hole produced when processing a nozzle plate becomes high, a nozzle hole with high shape precision can be formed. Furthermore, since at least one surface of the nozzle plate is protected by the sacrificial member in the nozzle plate processing step, in a series of steps of mask pattern formation, etching, cleaning, and mask pattern removal when creating the nozzle plate, There is no danger of scratches such as scratches.

  For this reason, there is an effect that a nozzle plate having a large number of nozzle holes can be manufactured stably with high shape accuracy and with a high yield.

  In the nozzle plate manufacturing method according to the present invention, as described above, since the sacrificial member further includes a substrate and a layered member formed on the substrate, the surface of the sacrificial member is smooth and smooth. It is easy to control with high accuracy. Therefore, large unevenness formed on the surface of the sacrificial member is not transferred to the ejection surface of the first nozzle layer formed on the sacrificial member. For this reason, it is possible to manufacture a nozzle plate with little variation in shape on the liquid ejection surface of the first nozzle hole and high ejection stability.

  As described above, the manufacturing method of the nozzle plate according to the present invention further includes a shielding layer having higher etching resistance than the first nozzle layer with respect to the etching processing means of the first nozzle hole on the first nozzle layer. A step of forming a through hole in the shielding layer, and a step of etching the first nozzle hole using the shape of the through hole formed in the shielding layer as a mask. After the etching process, the sacrificial member is etched to separate the first nozzle layer from the sacrificial member, so that a nozzle hole that controls droplet discharge stability is formed in the shielding layer. Since the hole shape is used as a mask, there is little change in the shape of the through hole during processing, and there is little change in the processing shape of the nozzle hole due to overetching or thickness variation of the first nozzle layer. An effect that it is possible to perform time high reproducible good processability.

  As described above, the method for manufacturing a nozzle plate according to the present invention further includes a step of forming a shielding layer, and etching means for etching the first nozzle hole and the second nozzle hole on the first nozzle layer. A shielding layer having higher etching resistance than the first nozzle layer and the second nozzle layer, and the second nozzle layer is formed on the shielding layer and on the portion where the shielding layer is not formed on the first nozzle layer. A step of forming a nozzle layer, and a step of forming, by etching, a second nozzle hole reaching the shielding layer from the surface of the second nozzle layer in the second nozzle layer, the first nozzle hole and the second nozzle layer The first nozzle layer and the sacrificial member are separated by etching the sacrificial member after the nozzle hole is etched, so that the processing of the nozzle hole governing the droplet discharge stability is performed on the shielding layer. In Since the formed through-hole shape is used as a mask, there is little change in the shape of the through-hole during processing, and there is little change in the processed shape of the nozzle hole due to overetching or variations in the thickness of the first nozzle layer. Highly reproducible processing can be performed. Furthermore, since the processing of the second nozzle hole formed in the second nozzle layer that retains the rigidity of the entire nozzle plate can be stopped with a shielding layer with high accuracy, the shape change is small due to the high rigidity, and the liquid There is an effect that it is possible to manufacture a nozzle plate with high shape accuracy of the droplet discharge port.

  In the nozzle plate manufacturing method according to the present invention, as described above, the step of etching the second nozzle hole and the step of etching the first nozzle hole are the same in this order. Since the second nozzle hole etching process and the first nozzle hole etching process are successively performed in this order in the same etching apparatus, the etching apparatus and the etching solution or the etching gas are used. Etching can be performed as it is. As a result, the manufacturing process can be simplified.

  As described above, the method for manufacturing a nozzle plate according to the present invention further includes a step of bonding a reinforcing plate on the shielding layer and on a portion where the shielding layer is not formed on the first nozzle layer, After joining the reinforcing plate, the sacrificial member is etched to separate the first nozzle layer from the sacrificial member. Therefore, after joining the reinforcing plate, the sacrificial member is etched to separate the first nozzle layer from the sacrificial member. Therefore, the rigidity of the entire nozzle plate can be increased by the reinforcing plate, and the effect that the warpage and deformation of the nozzle plate can be reduced is achieved.

  In the nozzle plate manufacturing method according to the present invention, as described above, the sacrificial member is further etched using an acid or alkaline solution. Therefore, the sacrificial member can be etched by isotropic etching. Therefore, the sacrificial member can be etched at high speed, and the time required for the nozzle manufacturing process can be shortened. In addition, since the etching using the above solution does not require a vacuum apparatus, there is an effect that the process can be easily performed at a high throughput.

The nozzle plate manufacturing method according to the present invention includes a step of preparing a sacrificial member made of a material mainly composed of Ni, Cu, or Al, and polyimide, Si, SiO ₂ , Si, as described above. A step of forming a first nozzle layer or a second nozzle layer made of a material containing at least one of ₃ N ₄ as a main component, Ti, W, Nb, Au, Pt, SiO ₂ , Si ₃ The nozzle includes a step of forming a shielding layer mainly composed of one or more of N ₄ and Al ₂ O ₃ and a step of etching the sacrificial member with an aqueous solution containing nitric acid or potassium hydroxide. Since the sacrificial member can be etched by an etching method having high selectivity with respect to the material constituting the plate, the shape of the nozzle hole is changed in the sacrificial member etching process. There is an effect that the reliability is not reduced due to the formation of the shielding layer, the deformation of the shielding layer, the peeling of the nozzle plate or the like.

  In the nozzle plate manufacturing method according to the present invention, the sacrificial member is further etched using oxygen-containing plasma as described above, so that the nozzle plate is not wetted in the process. For this reason, the nozzle plate separated from the substrate during etching or water cleaning does not stick to the inner wall of the container used for etching or water cleaning or the substrate once separated, thereby further preventing damage to the nozzle plate surface. There is an effect that can be.

As described above, the method for manufacturing a nozzle plate according to the present invention further includes a step of preparing a sacrificial member made of a material whose main component is polyimide at least in part, and among the Si, SiO ₂ , and Si ₃ N ₄ A step of forming a first nozzle layer or a second nozzle layer made of a material having at least one as a main component, and Al, Cu, Ni, Fe, Co, Au, Pt, or Al ₂ O ₃ Since it has the process of forming the shielding layer which has one or more as a main component, and the process of etching the said sacrificial layer using the plasma containing oxygen, it has high selectivity with respect to the material which comprises a nozzle plate Since the sacrificial member can be etched by the etching method, the reliability of the sacrificial member etching process is low due to a change in nozzle hole shape, deformation of the shielding layer, peeling of the nozzle plate, and the like. It has the effect of not inviting the bottom.

  In the nozzle plate manufacturing method according to the present invention, as described above, the outer shape processing of the nozzle plate is simultaneously performed at the time of the first nozzle hole processing or the second nozzle hole processing. A plurality of nozzle plates can be arranged at the same time and manufactured at the same time, so that the throughput for manufacturing the nozzle plates can be improved. Furthermore, since the outer shape of the nozzle plate is also processed at the end of nozzle hole processing, there is no need to process the outer shape in a separate process, thereby further reducing the risk of damage to the nozzle plate, resulting in the nozzle plate The production stability of can be improved.

[Embodiment 1]
The following describes Embodiment 1 of the present invention with reference to the drawings.

(Nozzle plate)
FIG. 1A is a perspective view of a part of a nozzle plate of the present invention used in a fine dot forming apparatus, and FIG. 1B is a cross-sectional view taken along the line AA ′ in FIG. It is. One or more liquid (liquid substance) discharge ports 9 are formed in the nozzle plate, and two liquid discharge ports 9 are shown in FIG.

  As shown in FIGS. 1A and 1B, the nozzle plate 8 includes a first nozzle layer 1, a second nozzle layer 2, a stopper layer 3 (shielding layer), a liquid repellent film 4, and nozzle holes 11. . A liquid repellent film 4 is formed on the liquid ejection surface side of the first nozzle layer 1, and a second nozzle layer 2 is formed on the opposite side. The stopper layer 3 is located at the interface between the first nozzle layer 1 and the second nozzle layer 2 in the second nozzle layer 2 and is in contact with the first nozzle layer 1, and the liquid discharge port 9 serves as an opening. The first nozzle hole 11a is formed locally at the position where the first nozzle hole 11a is formed. That is, the first nozzle hole 11a passes through the liquid repellent film 4 and the first nozzle layer 1, and further passes through the central portion of the stopper layer 3 formed locally.

  More specifically, the stopper layer 3 has a shape whose center substantially coincides with the center of the cylindrical hole of the first nozzle hole 11a when viewed from the direction of liquid discharge from the first nozzle hole 11a. By extending the nozzle hole 11a, the center part is formed in a circular shape. In this example, the surface of the stopper layer 3 viewed from the liquid ejection direction is a quadrangle (here, a square) as shown in FIG. In this example, the stopper layer 3 is not formed on at least the entire surface of the first nozzle layer 1 or the second nozzle layer 2, and as shown in FIG. The stopper layer 3 is not formed, and the first nozzle layer 1 and the second nozzle layer 2 are in direct contact. Further, the thickness of the stopper layer 3 is set to be thinner than the thickness of the first nozzle layer 1.

  The second nozzle hole 11b forms a nozzle hole 11 together with the first nozzle hole 11a, and has a tapered shape (conical truncated cone shape) that expands from the communicating portion with the cylindrical first nozzle hole 11a so as to spread out from the bottom. Yes, it passes through the second nozzle layer 2 and opens on the surface 2 b on the opposite side of the liquid repellent film 4.

  The upper bottom 11y of the second nozzle hole 11b having a truncated cone shape has an annular shape centering on the first nozzle hole 11a, and the stopper layer 3 is exposed to form the upper bottom 11y. Therefore, the diameter of the communication portion 11x (substantially circular) between the first nozzle hole 11a and the second nozzle hole 11b is the outer diameter of the upper bottom 11y of the second nozzle hole 11b (the outer shape of the second nozzle hole 11b in the communication portion 11x). ), The stopper layer 3 is smaller by the area overhanging the second nozzle hole 11b. Here, as already described, the substantially circular opening of the first nozzle hole 11 a is the liquid discharge port 9. The substantially circular opening of the second nozzle hole 11 b is a liquid supply port 12.

  Specific examples of the size and material of each part will be described below, but the present invention is not limited to the specific examples.

  A polyimide film having a thickness of about 1 μm is used for the first nozzle layer 1, and a polyimide film having a thickness of about 20 μm is used for the second nozzle layer 2. That is, in this example, the material is the same in the first nozzle layer 1 and the second nozzle layer 2. In this example, the thickness of the second nozzle layer 2 is thicker than the thickness of the first nozzle layer 1.

  The stopper layer 3 is made of a metal material mainly composed of Ti, and has a substantially square shape with a side of about 20 μm in order to reduce warpage due to the stress of the entire nozzle plate 8.

  The diameter of the opening (liquid discharge port 9) of the first nozzle hole 11a is about 3 μm. The outer diameter of the upper bottom 11y of the second nozzle hole 11b is 10 μm, and the diameter of the opening (liquid inlet 12) is 30 μm.

  The liquid repellent film 4 on the first nozzle layer 1 is formed of a fluorine polymerized or silicon polymer film.

According to the present embodiment, since the stopper layer 3 is locally provided for each position where the nozzle holes 11 are formed, the stopper is provided over the entire interface between the first nozzle layer and the second nozzle layer as in the prior art. Compared with the configuration in which the layer (SiO ₂ layer 26 in FIG. 11) is formed, the generation of stress due to the difference in linear expansion coefficient between the first nozzle layer 1 and the second nozzle layer 2 and the stopper layer 3 is greatly increased. Therefore, it is possible to prevent the nozzle plate 8 from being greatly warped.

  Moreover, since generation | occurrence | production of the above stress can be suppressed, the rigidity requested | required of the 1st nozzle layer 1 and the 2nd nozzle layer 2 can be small. Thereby, the layer thickness of the first nozzle layer 1 or the second nozzle layer 2 is compared with the conventional configuration (the Si layer 24 shown in FIGS. 11A and 11B is 15 μm and the Si layer 25 is 100 μm). (In this embodiment, the first nozzle layer 1 is 1 μm and the second nozzle layer 2 is 20 μm). Accordingly, when the first nozzle hole 11a and the second nozzle hole 11b are etched as will be described later, the etching amount of the first nozzle layer 1 and the second nozzle layer 2 can be reduced, and the formation error can be reduced. Therefore, the nozzle hole 11 with high formation accuracy can be provided.

  In addition, since the second nozzle hole 11b has a tapered shape, it is difficult for liquid turbulence to occur inside the second nozzle hole 11b, and the droplet ejection stability can be improved.

  In addition, since the second nozzle layer 2 can be made thinner than the conventional configuration as described above, the liquid inlet 12 is compared with the conventional configuration even if the second nozzle hole 11b is formed in a tapered shape. And can be made smaller. Thereby, the integration degree of the nozzle hole 11 can be raised.

  Further, the liquid repellent film 4 can prevent droplets from adhering to the first nozzle layer 1 in the vicinity of the first nozzle hole 11a.

The material used for the first nozzle layer 1 is not limited to polyimide. It may be a polymer organic material other than polyimide, Si compound material such as SiO ₂ or Si ₃ N ₄ , or Si.

Further, the material used for the stopper layer 3 is not limited to a metal material mainly containing Ti. In the etching process of the first nozzle layer 1 and the second nozzle layer 2 and the etching of the sacrificial layer 5 described later, a material having high resistance to the etching, that is, an etching gas (plasma containing oxygen and fluorine) As long as the material is highly resistant to an etchant (such as nitric acid or an aqueous potassium hydroxide solution). Specifically, a metal material mainly containing Ti, Al, Cu, Au, Pt, Ta, W, Nb, etc., an inorganic oxide material mainly containing SiO ₂ , Al ₂ O _3, etc., Si ₃ N Examples include inorganic nitride materials mainly containing _{4 and the} like, and can be selected from the above materials in combination with the above etching method.

Further, the material used for the second nozzle layer 2 is not limited to polyimide. Similar to the first nozzle layer 1, it may be a high molecular organic material other than polyimide, a Si compound material such as SiO ₂ or Si ₃ N ₄ , or Si.

  Further, the shape of the stopper layer 3 is not limited to a substantially square shape as long as it is a shape localized at the position where the nozzle hole 11 is formed. For example, it may be circular. A circular shape is preferred because it has the highest isotropy of the shape, and stress reduction is isotropic. In addition, as shown in FIG. 1A, in the present embodiment, one nozzle hole 11 is formed for one stopper layer 3, but the present invention is not limited to this. A plurality of nozzle holes 11 may be formed in one stopper layer 3 as long as stress can be suppressed as compared with the conventional configuration.

  In the present embodiment, as shown in FIG. 1B, the diameter of the communication portion 11x of the first nozzle hole 11a and the second nozzle hole 11b is smaller than the diameter of the upper bottom 11y of the second nozzle hole 11b. However, it is not limited to this. The diameter of the communication part 11x may be the same as the diameter of the contact part 11y. In the present embodiment, the second nozzle hole 11b has a truncated cone shape (tapered shape) in which the communication portion 11x with the first nozzle hole 11a is narrowed, but is not limited thereto. For example, as shown in FIG. 2, the side wall of the second nozzle hole 11 b can be formed in a so-called straight shape (cylindrical shape) perpendicular to the stopper layer 3. In this case, the liquid inlet 12 of the second nozzle hole 11b can be made smaller, and the degree of nozzle integration can be further increased. Further, the second nozzle hole 11b may have a bulging taper shape as shown in FIG.

As described above, by configuring the nozzle plate to include the first nozzle layer 1, the stopper layer 3, and the second nozzle layer 2,
(1) Since the processing accuracy of the first nozzle layer 1 having a thickness of 1 μm dominates the shape of the liquid discharge port 9, the shape accuracy of the liquid discharge port 9 can be improved.
(2) Since the rigidity of the nozzle plate 8 can be maintained by the second nozzle layer 2, the rigidity of the entire nozzle plate 8 is increased and the handling becomes easy.
(3) Since the shape of the stopper layer 3 can be set to the minimum necessary, warpage of the nozzle plate 8 due to stress can be reduced.
(4) Since the thickness of the nozzle plate 8 can be kept to the minimum necessary, the liquid inlet 12 of the nozzle plate 8 can be reduced, and thereby the degree of integration of the nozzle holes 11 can be improved. Accordingly, an image with high resolution can be drawn.
(5) Since the second nozzle layer 2 is reinforced by the thick film, the rigidity of the entire nozzle plate 8 is high and warpage is unlikely to occur, and the handling becomes easy.
(6) Even if the processing accuracy of the second nozzle hole 11b processed into the thick second nozzle layer 2 is not good, the etching stops at the stopper layer 3 when processing the second nozzle hole 11b, so that the discharged liquid The first nozzle hole 11a that controls the size of the droplet is not affected.
(7) Since the nozzle layer 8 is set so that the stopper layer 3 is thinner than the first nozzle layer 1, the stopper layer 3 is not used when the stopper layer 3 is etched using a photolithography technique. Compared to the case where the first nozzle layer 1 is directly processed using a photolithography technique, the shape accuracy of the processing is high, and the first nozzle layer 1 is processed by a processing method having high etching selectivity using the stopper layer 3 as a mask. Therefore, the first nozzle hole 11a for controlling the size of the discharged droplet can be formed with high accuracy.
(8) When SiO ₂ or Si ₃ N ₄ is used for the first nozzle layer 1, when the liquid repellent film 4 is formed on the first nozzle layer 1, the adhesion of the liquid repellent film 4 is improved. Since peeling or chipping of the liquid film 4 is prevented, the ejection direction of the ejected droplets is stabilized, and the resolution of the drawn image is improved.

(Nozzle plate manufacturing method)
Next, a method for manufacturing the nozzle plate according to the present embodiment will be described. FIGS. 3A to 3G are diagrams for explaining a manufacturing process of the nozzle plate according to the present embodiment. FIG. 4 is a modification of the process shown in FIG.

  First, the sacrificial member 6 for temporary holding of arbitrary thickness is prepared. In the present embodiment, the sacrificial member 6 is composed of a substrate 51 made of Si or glass and a sacrificial layer 5, and the sacrificial layer 5 is formed by depositing Ni by wet plating (FIG. 3A). reference). The thickness of the sacrificial layer 5 is 10 μm. Here, a first nozzle layer is laminated on the surface of the sacrificial member 6 (the surface of the sacrificial layer 5 in the present embodiment) in a process to be described later, and the interface between the first nozzle layer 1 and the sacrificial member 6 is the nozzle. Since the surface is on the liquid ejection surface side of the plate, it is desirable that the surface of the sacrificial member 6 has as little as possible unevenness. From this viewpoint, in this embodiment, the sacrificial layer 5 is formed on the substrate 51 such as Si or glass that can easily achieve high flatness and smoothness by a wet plating method that easily reflects the surface shape of the substrate. A sacrificial member 6 was constructed. However, a metal block such as Ni whose surface flatness and smoothness are controlled by high-precision surface processing can also be used as the sacrificial member 6.

  Next, a coating-type polyimide resin is formed on the sacrificial layer 5 with a thickness of 1 μm to form the first nozzle layer 1 (first step, FIG. 3B). Here, the coating type polyimide resin was applied on the sacrificial layer 5 by spin coating and baked at 350 ° C. for 2 hours.

  Next, the stopper layer 3 is formed on the first nozzle layer 1 (second step, FIG. 3C). First, a stopper layer 3 having a thickness of 0.5 μm (5000 mm) is formed by sputtering using a material mainly composed of Ti. Then, after forming a resist pattern having a predetermined shape by photolithography, the stopper layer 3 is processed into a substantially square shape with a side of 20 μm by dry etching using Ar ions such as ion milling. In this dry etching, one opening 11a1 having a diameter of 3 μm is formed inside the substantially square shape. The opening 11a1 is a formation pattern of a first nozzle hole 11a described later, and becomes a part of the first nozzle hole 11a.

  Next, the second nozzle layer 2 is formed to a thickness of 20 μm on the first nozzle layer 1 and the stopper layer 3 (third step, FIG. 3D). As with the first nozzle layer 1, the second nozzle layer 2 was coated with a coating type polyimide resin by a spin coating method and baked at 350 ° C. for 2 hours to a thickness of 20 μm. Here, the opening 11a1 of the stopper layer 3 is also filled with the polyimide resin.

  Next, a resist pattern 7 is formed on the second nozzle layer 2 by photolithography, and dry etching using a gas containing oxygen as a main component is performed, so that the second nozzle layer 2 has a tapered shape (conical truncated cone shape). A second nozzle hole 11b was formed (fourth step, FIG. 3 (e)). The dry etching can be stopped by the stopper layer 3. That is, dry etching does not proceed any further in the portion where the stopper layer 3 is exposed except for the opening 11a1 of the stopper layer 3.

  When processing the tapered shape of the second nozzle hole 11b, in the above etching, the etching rate of the resist pattern 7 and the etching rate of the polyimide resin of the second nozzle layer 2 are substantially equal, and the resist pattern 7 is heated at 150 ° C. for 60 minutes. The resist pattern 7 was tapered by post-baking, and a method of transferring this shape to the second nozzle layer 2 by etching was used.

  That is, as shown in FIG. 9, a resist pattern 7 having an almost equal taper cross section as the polyimide resin (second nozzle layer 2) is formed, and the resist pattern 7 is etched at the same speed as the polyimide resin etching, The edge of the resist pattern 7 is widened. At this time, the polyimide resin (second nozzle layer 2) is also etched, so that the etching wall surface (wall surface of the second nozzle hole 11b) has the same shape as the tapered wall surface (resist pattern 7) initially formed by resist. Become.

  It should be noted that the resist pattern 7 and the second nozzle layer 2 have substantially the same etching rate, and therefore it is desirable that the resist pattern 7 is formed thicker than the second nozzle layer 2.

  In addition, an outer shape pattern of a nozzle plate (not shown) can be created using the resist. In this configuration, the outer shape of the nozzle plate can be processed simultaneously with the processing of the second nozzle hole in the second nozzle hole processing step. The outer shape of the nozzle plate is processed simultaneously with the first nozzle hole even when the first nozzle hole described below is processed, and the outer shape of the nozzle plate is also processed simultaneously with the completion of the first nozzle hole processing. By processing the outer shape of the nozzle plate simultaneously with the first nozzle hole and the second nozzle hole in this way, the following effects can be obtained.

  That is, since a plurality of nozzle plates can be arranged on one substrate and manufactured at the same time, the throughput for manufacturing the nozzle plate can be improved. Furthermore, since the outer shape of the nozzle plate is also processed at the end of nozzle hole processing, there is no need to process the outer shape in a separate process, thereby further reducing the risk of damage to the nozzle plate, resulting in the nozzle plate The production stability can be improved.

  Next, etching for processing the first nozzle holes 11a in the first nozzle layer 1 is performed continuously with the fourth step (fifth step, see FIG. 3E). At this time, the 1st nozzle hole 11a is processed into the shape (substantially circular, a diameter is 3 micrometers) determined by the opening part 11a1 of the stopper layer 3 processed at the previous process. At this time, since the stopper layer 3 is hardly etched by the dry etching mainly containing oxygen in this step, the pattern formed in the stopper layer 3 does not change, and the first nozzle hole 11a is formed as shown in FIG. The first nozzle hole 11a can be formed with high accuracy by being processed substantially vertically.

  Next, the resist pattern 7 is removed using a resist stripping solution, and the nozzle plate 8 is removed from the substrate 51 by immersing in an aqueous solution mainly composed of nitric acid and water and etching only the sacrificial layer 5 (FIG. 3 (f)). At this time, it is not necessary to completely remove the sacrificial layer 5 by etching, and the nozzle plate 8 is separated from the sacrificial member 6 by etching and removing only the sacrificial layer 5 at the interface with which the first nozzle layer 1 is in contact. can do. Further, as described above, the polyimide resin forming the first nozzle layer 1 and the second nozzle layer 2 and Ti forming the stopper layer 3 are hardly etched by the etching solution for the sacrificial layer 5. Therefore, the etching of the sacrificial layer 5 does not cause a change in shape or a decrease in structural reliability.

  Next, the liquid repellent film 4 is formed on the surface of the first nozzle layer 1 (FIG. 3G). Here, a fluoropolymer was used for the purpose of considering the ease of application, and this was applied to the surface of the first nozzle layer 1 by a method such as stamping to form the liquid repellent film 4 with a polymer film. In addition, the liquid repellent film which entered the first nozzle hole 11a was removed by dry etching from the second nozzle hole 11b side using plasma containing oxygen after the liquid repellent film was formed. Thereby, damage to the nozzle plate 8 can be minimized.

  According to the present embodiment, when the first nozzle hole 11a is etched, the first nozzle hole 11a is etched using the stopper layer 3 as a mask (shielding layer), so that the first nozzle hole 11a can be formed with high accuracy.

  Further, when the second nozzle layer 2 is etched, the etching is automatically stopped by the stopper layer 3, and the etching depth of the second nozzle hole 11b can be defined.

  Further, as the material of the stopper layer 3, an optimum material can be selected as a shielding layer at the time of etching the first nozzle hole 11a or as a side wall of the first nozzle hole 11a. Thereby, the first nozzle hole 11a can be formed with higher accuracy. Further, since the first nozzle layer 1 or the second nozzle layer 2 is joined directly or indirectly to the sacrificial member 6, the sacrificial member 6 can maintain the rigidity of the nozzle plate, and the first nozzle layer 1 or the second nozzle layer. 2 can be formed thinly, the etching amount of the first nozzle layer 1 and the second nozzle layer 2 can be reduced when the first nozzle hole 11a and the second nozzle hole 11b are etched, and the formation error is reduced. Therefore, the nozzle hole 11 can be formed with high accuracy.

  Specifically, when the shape of each liquid discharge port 9 of the nozzle plate 8 having 200 liquid discharge ports 9 created by using the process of the present embodiment is evaluated, the variation is very large as ± 0.2 μm. We were able to process with high accuracy. Also, the warpage of the nozzle plate 8 was very flat at 10 μm or less.

  Furthermore, when the first nozzle hole 11a and the second nozzle hole 11b are etched, the stopper layer 3 is etched from one direction, so that etching is performed from two directions so as to face each other as in the conventional method. In comparison, the first nozzle hole 11a and the second nozzle hole 11b can be easily aligned.

  Furthermore, in the first nozzle hole 11a and second nozzle hole 11b forming steps (fourth step and fifth step), the etching in the fourth step is used as it is, and the etching in the fifth step is performed as it is. It can be carried out. Thereby, the manufacturing process can be simplified.

  In the present embodiment, Ni is used as the sacrificial layer 5, polyimide resin is used as the first nozzle layer 1 and the second nozzle layer 2, and Ti is used as the stopper layer 3. However, the present invention is not limited to this combination.

  In addition to Ni, the sacrificial layer 5 is made of a material that is soluble in nitric acid such as Al, Cu, or KOH aqueous solution in combination with materials used for the first nozzle layer 1, the second nozzle layer 2, and the stopper layer 3. Alternatively, a material that can be etched by oxygen plasma, such as polyimide, can be used. In addition to the plating, the sacrificial layer 5 can be formed by using a vapor deposition method, a sputtering method, a coating method, or the like depending on the material.

  For the first nozzle layer 1 and the second nozzle layer 2, a material that is slightly damaged by etching of the sacrificial layer 5 can be used. The stopper layer 3 can be made of a material that is highly resistant to the etching of the sacrificial layer 5 and the etching of the first nozzle hole 11a and the second nozzle hole 11b.

  Here, Table 1 shows preferable combinations of materials used (sacrificial layer, first nozzle layer, stopper layer, second nozzle layer) and processing method (stopper layer, first nozzle hole, second nozzle hole, sacrificial layer removal). Indicates.

表１に示すように、第１ノズル層１、第２ノズル層２はポリイミド樹脂のような高分子有機材料に限定されず、ＳｉまたはＳｉＯ₂などの無機シリコン化合物を選択することができる。ただし、ＳｉＯ₂やＳｉをドライエッチングするためには、Ｆを含有する反応ガスを使用する必要があり、このエッチングに対して本実施の形態で用いたＴｉは耐性が低いため、Ａｕなどのエッチング耐性を有する材料をストッパ層３として利用することが望ましい。

As shown in Table 1, the first nozzle layer 1 and the second nozzle layer 2 are not limited to a polymer organic material such as a polyimide resin, and an inorganic silicon compound such as Si or SiO ₂ can be selected. However, in order to dry-etch SiO ₂ and Si, it is necessary to use a reaction gas containing F. Since Ti used in this embodiment has low resistance to this etching, etching such as Au It is desirable to use a material having resistance as the stopper layer 3.

In addition to Ti, the materials shown in the table can be used for the stopper layer 3 according to the combinations shown in Table 1. Note that Ti, which is the material of the stopper layer 3, can be etched by plasma using a mixed gas of CF ₄ and oxygen. However, the first nozzle layer 1 (polyimide) formed under Ti is etched at a higher speed than Ti due to the plasma of the gas, and is greatly damaged. Therefore, in this embodiment, the dry etching method using Ar ions is employed for patterning the stopper layer 3. In this way, by adopting the dry etching method using Ar ions in which the difference between the etching rate of the stopper layer 3 and the etching rate of the first nozzle layer 1 is small, the stopper is suppressed while minimizing damage to the first nozzle layer 1. Layer 3 can be patterned.

  In step 2, the stopper layer 3 is formed in a square shape, but the present invention is not limited to this. When the second nozzle hole 11b is formed, any shape and size may be used as long as the second nozzle hole 11b reaches the stopper layer 3 and the progress of etching is stopped. However, it is desirable that the shape and size (minimum required size) can reduce the warpage of the nozzle plate 8 due to the stress of the stopper layer 3.

  Further, in step 2, the shape of the stopper layer 3 and the opening 11a1 that becomes the formation pattern of the first nozzle holes 11a are simultaneously formed, but it is also possible to create them by two etching steps. Furthermore, in step 2, as shown in FIG. 4, the first nozzle hole 11a can be processed at the time of creating the nozzle hole processing pattern (stopper layer 3 having the opening 11a1). However, in this case, when the second nozzle layer 2 is formed (step 3), the previously processed opening 11a1 is filled, so that the portion is processed again in step 5.

  In Step 4, the mask material and the etching conditions for processing the second nozzle hole 11b are optimized, and the side wall has a bulge (curved surface) as shown in FIGS. Two nozzle holes 11b can also be formed.

That is, as shown in FIGS. 8A to 8C, SiO ₂ or the like having high resistance to oxygen plasma etching is formed as a mask 13 on the second nozzle layer 2 (see FIG. 8A), The plasma etch is performed at a high gas pressure, for example, 500 mTorr (see FIG. 8B). As a result, an undercut is generated under the mask 13 and a swelled taper can be formed (see FIG. 8C).

  However, if the etching is over-etching, the diameter d of the second nozzle hole 11b is widened at the contact portion between the second nozzle hole 11b and the stopper layer 3, and the large-area stopper layer 3 is required. It is preferable to control.

  The liquid repellent film 4 is not limited to a fluoropolymer, and a silicon-based polymer film, DLC (diamond-like carbon), or the like can also be used.

By using the above processing steps,
(1) Since the first nozzle hole 11a is processed by a highly selective processing means using the opening 11a1 of the stopper layer 3 as a mask, there is little change in the shape of the opening 11a1 during processing, and overetching or the first nozzle layer The variation of the processing shape of the first nozzle hole 11a due to the variation in the thickness of the first nozzle is small, and processing with high shape accuracy and good reproducibility can be performed.
(2) Since the second nozzle hole 11b is processed by processing means having high selectivity with respect to the stopper layer 3, the processing of the second nozzle hole 11b can be stopped by the stopper layer 3 with high reproducibility. For this reason, the influence of the processing accuracy of the second nozzle hole 11b on the processing accuracy of the first nozzle hole 11a is slight, the shape accuracy of the liquid discharge port 9 is high, and the nozzle plate 8 having a thick layer is stably manufactured. can do.
(3) Since the interface between the first nozzle layer and the sacrificial layer that becomes the droplet discharge surface of the nozzle plate is protected by the sacrificial layer until the final stage of the process, the droplet discharge surface is damaged in the nozzle plate manufacturing process. The nozzle plate having a large number of nozzle holes with high shape accuracy can be stably manufactured.

[Embodiment 2]
The following describes Embodiment 2 of the present invention with reference to the drawings.

(Nozzle plate)
FIG. 5A is a perspective view of a part of the nozzle plate of the present invention used in the fine dot forming apparatus, and FIG. 5B is a cross-sectional view taken along the line BB ′ in FIG. It is. One or more liquid (liquid substance) discharge ports 90 are formed in the nozzle plate, and two liquid discharge ports 90 are shown in FIG.

  As shown in FIG. 5A, the nozzle plate 80 includes a nozzle layer 10, a stopper layer 30 (shielding layer), a reinforcing plate 20, and nozzle holes 110. A liquid repellent film 40 is formed on the liquid ejection surface side of the nozzle layer 10, and a reinforcing plate 20 is bonded to the opposite side. In this example, the reinforcing plate 20 is thicker than the nozzle layer 10. The stopper layer 30 is located at the interface between the nozzle layer 10 and the reinforcing plate 20, and is locally formed at the position where the first nozzle hole 110a having the liquid discharge port 90 as an opening is formed. That is, the first nozzle hole 110a penetrates the liquid repellent film 40 and the nozzle layer 10 and penetrates the central portion of the locally formed stopper layer 30.

  More specifically, the stopper layer 30 has a shape whose center substantially coincides with the center of the cylindrical hole of the first nozzle hole 110a when viewed from the liquid discharge direction from the first nozzle hole 110a. The center of the nozzle hole 110a is formed in a circular shape by extending the nozzle hole 110a. In this example, the surface of the stopper layer 30 viewed from the liquid ejection direction is a quadrangle (here, a square) as shown in FIG. In this example, the stopper layer 30 is not formed on at least the entire surface of the nozzle layer 10 or the reinforcing plate 20, and as shown in FIG. 5A, the stopper layer 30 is provided between adjacent nozzles. The nozzle layer 10 and the reinforcing plate 20 are in direct contact with each other. Further, the thickness of the stopper layer 30 is set to be thinner than the thickness of the nozzle layer 10.

  The rectangular parallelepiped second nozzle hole 110b penetrates the reinforcing plate 20 and constitutes the nozzle hole 110 together with the cylindrical first nozzle hole 110a.

  Here, the stopper layer 30 is located inside the second nozzle hole 110b (within the opening range) at the interface between the nozzle layer 10 and the reinforcing plate 20. Therefore, the bottom surface (substantially square) corresponding to the opening of the second nozzle hole 110b serves as the liquid supply port 120, and the nozzle layer 10 and the inner side of the bottom surface 110y (substantially square) corresponding to the inner wall of the second nozzle hole 110b. A contact surface (substantially square with a hole) with the stopper layer 30 is located. Note that a communication portion 110x (substantially circular) between the first nozzle hole 110a and the second nozzle hole 110b is located on the inner side (center portion) of the contact surface.

  The nozzle layer 10 is formed of a polyimide film having a thickness of 1 μm in the present embodiment.

  The stopper layer 30 is made of a metal material mainly composed of Ti, and is formed in a substantially square shape with a side of 10 μm in order to reduce warpage due to the stress of the entire nozzle plate 80.

  The diameter of the opening (liquid discharge port 90) of the first nozzle hole 110a is 3 μm.

  The liquid repellent film 40 is formed from a polymer material having a fluoropolymer.

  The reinforcing plate 20 is made of Si having a thickness of 50 μm, and the opening (liquid supply port 120) of the substantially square second nozzle hole 110 b has a side of 30 μm.

  According to the present embodiment, the stopper layer 30 is formed in a small shape so as to be positioned inside the second nozzle hole 110b because it is sufficient if it becomes a shielding layer when the first nozzle hole 110a described later is etched. ing.

  Thus, the contact surface between the nozzle layer 10 and the stopper layer 30 can be minimized, and in addition, the contact surface between the reinforcing plate 20 and the stopper layer 30 can be eliminated. The generation of stress due to the difference in the linear expansion coefficient between the plate 20 and the stopper layer 30 can be significantly suppressed as compared with the conventional configuration or the configuration of the first embodiment. Thereby, it is possible to prevent the nozzle plate 80 from being greatly warped.

The material used for the nozzle layer 10 is not limited to polyimide. It may be a polymer organic material other than polyimide, Si compound material such as SiO ₂ or Si ₃ N ₄ , or Si.

Further, the material used for the stopper layer 30 is not limited to a metal material mainly containing Ti. When the nozzle layer 10 is etched and the sacrificial layer 50 described later is etched, it is resistant to materials having high resistance to the etching, that is, plasma containing oxygen, plasma containing fluorine, nitric acid, potassium hydroxide aqueous solution, etc. As long as the material is high. Specifically, a metal material or an inorganic oxide material or an inorganic nitride mainly containing Ti, Al, Cu, Au, Pt, Ta, W, Nb, SiO ₂ , Al ₂ O ₃ , Si ₃ N ₄ or the like. Materials and the like.

Further, the material used for the reinforcing plate 20 is not limited to Si. Si compound materials such as SiO ₂ and Si ₃ N ₄ may be used.

  Further, the shape of the stopper layer 30 is not limited to a substantially square shape as long as the shape is localized at the position where the nozzle hole 110 is formed. For example, it may be circular. A circular shape is preferred because it has the highest isotropy of the shape, and stress reduction is isotropic. Further, as shown in FIG. 5A, in the present embodiment, one nozzle hole 110 is formed for one stopper layer 30, but the present invention is not limited to this. A plurality of nozzle holes 110 may be formed in one stopper layer 30 as long as stress can be suppressed as compared with the conventional configuration.

  Further, the second nozzle hole 110b provided in the reinforcing plate 20 is not limited to a rectangular parallelepiped shape (the cross section is a square shape). It may be cylindrical or tapered (conical shape).

As described above, the nozzle plate is configured to include the nozzle layer 10, the stopper layer 30, and the reinforcing plate 20,
(1) Since the processing accuracy of the nozzle layer 10 having a thickness of 1 μm dominates the shape of the liquid discharge port 90, the shape accuracy of the liquid discharge port 120 can be improved.
(2) Since the rigidity of the nozzle plate 80 can be maintained by the reinforcing plate 20, the rigidity of the entire nozzle plate 80 is increased, and the handling becomes easy.
(3) Since the shape of the stopper layer 30 can be further reduced, warpage of the nozzle plate 80 due to stress can be reduced.
(4) Since the thickness of the nozzle plate 80 can be kept to the minimum necessary, the liquid inlet 120 of the nozzle plate 80 can be reduced, and thereby the degree of integration of the nozzle holes 110 can be improved. Accordingly, an image with high resolution can be drawn.
(5) Further, since the stopper layer 30 can be processed into a predetermined minimum shape without being affected by the shape of the second nozzle hole 110b formed in the reinforcing plate 20, a nozzle plate due to a difference in linear expansion coefficient. The warpage of 80 can be further reduced.
(6) In the nozzle plate 80, since the stopper layer 30 is set to be thinner than the nozzle layer 10, the nozzle layer is used without using the stopper layer 30 when the stopper layer 30 is etched using a photolithography technique. Compared to the case of processing 10 directly using photolithography technology, the shape accuracy of the processing is high, and the nozzle layer 10 can be processed by a processing method with high etching selectivity using the stopper layer 30 as a mask. The first nozzle hole 110a that controls the size of the droplets to be formed can be formed with high accuracy.

(Nozzle plate manufacturing method)
6A to 6G show the manufacturing process of the nozzle plate according to the present embodiment. Below, the manufacturing method of the nozzle plate concerning this Embodiment is demonstrated using the same figure.

  First, the sacrificial member 60 for temporary holding of arbitrary thickness is prepared. In the present embodiment, the sacrificial member 60 includes a substrate 510 made of Si or glass and a sacrificial layer 50, and the sacrificial layer 50 is formed by depositing Ni by wet plating (FIG. 6A). reference). The thickness of the sacrificial layer 50 is 10 μm. Here, the nozzle layer 10 is laminated on the surface of the sacrificial member 60 (the surface of the sacrificial layer 50 in the present embodiment) in a process described later, and the interface between the nozzle layer 10 and the sacrificial member 60 is the liquid ejection surface of the nozzle plate. Therefore, it is desirable that the surface of the sacrificial member 60 has as little as possible unevenness. From this viewpoint, in this embodiment, the sacrificial layer 50 is formed on the substrate 510 such as Si or glass that can easily realize high flatness and smoothness by a wet plating method that easily reflects the surface shape of the substrate. A sacrificial member 60 was configured. However, a metal block such as Ni whose surface flatness and smoothness are controlled by high-precision surface processing can be used as the sacrificial member 60.

  Next, a coating-type polyimide resin is formed on the sacrificial layer 50 to a thickness of 1 μm to form the nozzle layer 10 (FIG. 6B). Here, the coating type polyimide resin was applied on the sacrificial layer 50 by spin coating and baked at 350 ° C. for 2 hours.

  Next, a stopper layer 30 (shielding layer) is formed on the nozzle layer 10 (FIG. 6C). First, a stopper layer 30 having a thickness of 5000 mm is formed by sputtering using a material mainly composed of Ti. Then, after forming a resist pattern having a predetermined shape by photolithography, the stopper layer 30 is processed into a substantially square shape having a side of 10 μm by dry etching using Ar ions such as ion milling. During this dry etching, one opening 110a1 having a diameter of 3 μm is formed inside the substantially square shape. The opening 110a1 is a formation pattern of a first nozzle hole 110a, which will be described later, and becomes a part of the first nozzle hole 110a.

  Next, a resist pattern 70 having a pattern corresponding to the opening 110a1 of the stopper layer 30 is formed. That is, the opening 110 a 1 of the stopper layer 30 is formed so as to be positioned in the opening 70 a of the resist pattern 70. Thereafter, using the stopper layer 30 as a mask, the nozzle layer 10 is etched from the opening 110a1 to form the first nozzle hole 110a. This etching is performed by dry etching using a gas containing oxygen as a main component (FIG. 6D).

  Subsequently, the resist 70 is removed using a stripping solution or the like. Here, since the stopper layer 30 is hardly etched by the dry etching mainly containing oxygen in this step, the pattern formed in the stopper layer 30 does not change, and the first nozzle hole 110a is formed as shown in FIG. As shown, it is processed almost vertically.

  Therefore, the first nozzle hole 110a can be formed with extremely high processing accuracy of ± 0.1 μm, which is close to the pattern accuracy of photolithography, without any change in the processing shape due to overetching. Further, it is desirable that the thickness of the resist 70 is larger than the thickness of the nozzle layer 10, and in the present embodiment, the resist thickness is set to 2 μm.

  In addition, an outer shape pattern of a nozzle plate (not shown) can be created using the resist. In this configuration, in the first nozzle hole processing step, the outer shape of the nozzle plate can be processed simultaneously with the processing of the first nozzle hole, and the outer shape of the nozzle plate can be changed simultaneously with the completion of the first nozzle hole processing. Processing is complete. Thus, the following effects are acquired by processing the external shape of a nozzle plate simultaneously with a 1st nozzle hole.

  That is, since a plurality of nozzle plates can be arranged on one substrate and manufactured at the same time, the throughput for manufacturing the nozzle plate can be improved. Furthermore, since the outer shape of the nozzle plate is also processed at the end of nozzle hole processing, there is no need to process the outer shape in a separate process, thereby further reducing the risk of damage to the nozzle plate, resulting in the nozzle plate The production stability can be improved.

  Next, a reinforcing plate 20 having a rectangular parallelepiped second nozzle hole 110b having a side of 15 μm is positioned and bonded so that the stopper layer 30 is disposed in the second nozzle hole 110b (see FIG. 6E). . Here, the adhesion surface of each member (the nozzle layer 10 and the reinforcing plate 20) was observed with a camera or the like, and the above-mentioned members were moved by a predetermined amount from the observation position and mechanically joined.

  FIG. 10A shows positioning (alignment phase) in this method, and FIG. 10B shows joining (joining phase).

  First, as shown in FIG. 10A, in the reinforcing plate position measurement area 65, the joint surface of the reinforcing plate 20 is observed by the camera 61, and the contour pattern of the second nozzle hole 110b is measured. Similarly, in the nozzle layer position measurement area 67, the joining surface of the nozzle layer 10 is observed by the camera 62, and the contour pattern of the stopper layer 30 is measured.

  Next, as shown in FIG. 10B, the proper movement amounts of the nozzle layer 10 and the reinforcing plate 20 are calculated from the measurement results, and the nozzle layer 10 and the reinforcing plate 20 are joined to the joining area 66 according to the proper movement amount. Move to the proper position in (alignment phase).

  In the joining area 66, the joining surface is pressed up and down without observing in real time, and the reinforcing plate 20 and the nozzle layer 10 are joined.

  The reinforcing plate 20 is made of Si, and an epoxy system with high chemical resistance is used for the adhesive. At the time of bonding, it is desirable to cure at normal temperature so that the nozzle plate 80 is not warped due to the difference in linear expansion coefficient between the adhesive and the nozzle layer 10 or the reinforcing plate 20.

  Next, the nozzle plate 80 is removed from the substrate 510 by immersing in an aqueous solution containing nitric acid and water as main components and etching only the sacrificial layer 50 (see FIG. 6F). At this time, it is not necessary to completely remove the sacrificial layer 50 by etching, and the nozzle plate 80 can be separated from the sacrificial member 60 by etching and removing only the sacrificial layer 50 at the interface with which the nozzle layer 10 is in contact. it can. Further, the polyimide resin forming the nozzle layer 10, Ti forming the stopper layer 30, and Si forming the reinforcing plate 20 are hardly etched by the sacrificial layer 50 etching solution. Therefore, there is no change in shape or deterioration in structural reliability.

  Next, the liquid repellent film 40 is formed on the surface of the nozzle layer 10 (FIG. 6G). Here, for the purpose of considering the ease of application, a fluoropolymer was used, and this was applied to the surface of the nozzle layer 10 by a method such as stamping, whereby the liquid repellent film 40 was formed of a polymer film. The liquid repellent film 40 that has entered the first nozzle hole 110a is removed by dry etching from the second nozzle hole 110b side using plasma containing oxygen after the liquid repellent film 40 is formed. did. Thereby, damage to the nozzle plate 80 can be minimized.

  Here, a method of manufacturing the reinforcing plate 20 will be briefly described with reference to FIG.

  First, grooves having a width of 15 μm and a depth of 15 μm to be the second nozzle holes 110b are formed at predetermined intervals on a Si substrate 31 having a thickness of 200 μm in the direction of arrow D in the figure by a dicing device. Next, the Si substrate 32 having a thickness of 100 μm in the direction of the arrow D is bonded to the surface 33 on which the groove of the Si substrate 31 obtained by processing the groove is provided using an epoxy adhesive. Next, it cut | disconnects in the direction (arrow D direction in a figure) orthogonal to a groove | channel with a dicing apparatus. Thereby, a plurality of reinforcing plates 20 having a thickness of 50 μm in the direction of arrow F and having one row of second nozzle holes 110b (substantially square having a cross section of 15 μm on one side) along the direction of arrow E in FIG. it can.

  Here, the above method is merely an example of a method of manufacturing the reinforcing plate 20, and, for example, a row of second nozzle holes 110b (substantially square having a cross section of 15 μm on the side) along the direction of arrow E in the figure is indicated by arrow D in the figure. It is also possible to manufacture the reinforcing plate 20 having a plurality of rows in the direction. In this case, a plurality of Si substrates 31 processed with grooves may be used. Note that the second nozzle holes 110b arranged in a staggered manner can also be formed by using a plurality of the Si substrates 31 processed with the grooves and adjusting the position of the grooves or the joining position.

  According to the present embodiment, the stopper layer 30 may be of a size that becomes a shielding layer (mask) when the first nozzle hole 110a is etched. Therefore, the stopper layer 30 can be formed in a smaller shape as compared with the first embodiment.

  Further, since the reinforcing plate 20 and the nozzle layer 10 can be formed separately, the nozzle plate 80 can be manufactured simply and stably.

  When the shape of each discharge port of the nozzle plate 80 having 200 liquid discharge ports 90 created using the above process was evaluated, the variation was processed with extremely high accuracy of ± 0.2 μm. Further, the warpage of the nozzle plate 80 was very flat at 5 μm or less.

  In this embodiment, Ni is used for the sacrificial layer 50, polyimide resin is used for the nozzle layer 10, Si is used for the reinforcing plate 20, and Ti is used for the stopper layer 30. However, the present invention is not limited to this combination.

  In addition to Ni, the sacrificial layer 50 may be made of a material that is soluble in nitric acid such as Al, Cu, or KOH aqueous solution, or polyimide, depending on the combination of materials used for the nozzle layer 10, the reinforcing plate 20, and the stopper layer 30. A material that can be etched by such oxygen plasma can be used. As a method for forming the sacrificial layer 50, a vapor deposition method, a sputtering method, a coating method, or the like can be used in addition to the plating depending on the material.

  For the nozzle layer 10 and the reinforcing plate 20, a material that is slightly damaged by etching of the sacrificial layer 50 can be used. The stopper layer 30 can be made of a material that is highly resistant to the etching of the sacrificial layer 50 and the etching of the first nozzle hole 110a.

  Here, Table 2 shows preferable combinations of materials used (sacrificial layer, nozzle layer, stopper layer, reinforcing plate) and processing method (removal of stopper layer, first nozzle hole, sacrificial layer).

表２に示すように、ノズル層１０はポリイミド樹脂のような高分子有機材料に限定されず、ＳｉまたはＳｉＯ₂などの無機シリコン化合物を用いることができる。また、補強板２０についても、Ｓｉ以外にガラスやＡｌ₂Ｏ₃などを主成分とするセラミックあるいはポリイミド樹脂といった材料を使用することができる。

As shown in Table 2, the nozzle layer 10 is not limited to a polymer organic material such as polyimide resin, and an inorganic silicon compound such as Si or SiO ₂ can be used. In addition to the Si, the reinforcing plate 20 may be made of a material such as ceramic or polyimide resin mainly composed of glass, Al ₂ O ₃ or the like.

Note that Ti, which is the material of the stopper layer 30, can also be etched by plasma using a mixed gas of CF ₄ and oxygen. However, the nozzle layer 10 (polyimide) formed under Ti is etched at a higher speed than Ti due to the plasma of the gas, and is greatly damaged. Therefore, in this embodiment, the dry etching method using Ar ions is employed for patterning the stopper layer 30. In this way, by employing the dry etching method using Ar ions that has a small difference in etch rate between the stopper layer 30 and the nozzle layer 10, the stopper layer 30 can be patterned while minimizing damage to the nozzle layer 10. it can.

  The liquid repellent film 40 is not limited to a fluoropolymer, and a silicon-based polymer film, DLC (diamond-like carbon), or the like can also be used.

  Further, in the present embodiment, the reinforcing plate 20 is obtained by merely processing the second nozzle hole 110b in the Si plate. However, by changing the thickness of the reinforcing plate 20, the droplet discharge mechanism and the droplet discharge signal transmission are performed. Means can be arranged.

By using the above processing steps,
(1) Since the processing accuracy of the nozzle layer 10 having a thickness of 1 μm dominates the shape of the liquid discharge port 90, the shape accuracy of the liquid discharge port 90 can be improved.
(2) Since the rigidity of the nozzle plate 80 can be maintained by the reinforcing plate 20, the rigidity of the entire nozzle plate 80 is increased, and the handling becomes easy.
(3) Since the shape of the stopper layer 30 can be further reduced, warpage of the nozzle plate 80 due to stress can be reduced.
(4) Since the thickness of the nozzle plate 80 can be kept to the minimum necessary, the liquid inlet 120 of the nozzle plate 80 can be reduced, and thereby the degree of integration of the nozzle holes 110 can be improved. Accordingly, an image with high resolution can be drawn.
(5) The nozzle plate 80 can be manufactured easily and stably.
(6) Since the interface between the nozzle layer and the sacrificial layer that becomes the droplet ejection surface of the nozzle plate is protected by the sacrificial layer until the final stage of the process, the droplet ejection surface is damaged in the nozzle plate manufacturing process. No nozzle plate having many nozzle holes with high shape accuracy can be manufactured stably.

  In addition, the nozzle plate 8 (80) of the said embodiment can also be characterized by the film thickness of the said stopper layer 3 (30) being thinner than the 1st nozzle layer 1 (nozzle layer 10).

  In the nozzle plate 8 (80) configured as described above, the stopper layer 3 (30) is set to be thinner than the first nozzle layer 1 (nozzle layer 10). Therefore, the stopper layer 3 (30) is formed using a photolithography technique. When the etching process is performed, the shape accuracy of the process is higher than when the first nozzle layer 1 (nozzle layer 10) is directly processed using the photolithography technique without using the stopper layer 3 (30). Since the first nozzle layer 1 (nozzle layer 10) can be processed by the processing method with high etching selectivity using the layer 3 (30) as a mask, the first nozzle hole 11a for controlling the size of the ejected droplets. (110a) can be formed with high accuracy.

  In the nozzle plate 8 of the above embodiment, the first nozzle layer 1 or the second nozzle layer 2 is formed of a polymer organic material or a material selected from Si or an inorganic silicon compound, respectively, and the stopper layer 3 is The first nozzle layer 1 or the second nozzle layer 2 may be formed of a material having high resistance to the processing means.

  Since the nozzle plate 8 having the above-described configuration is formed in the first nozzle layer 1 so that the first nozzle hole 11a penetrates the stopper layer 3, the shape accuracy of the first nozzle hole 11a is high. In addition, since the second nozzle hole 11b formed in the second nozzle layer 2 does not penetrate the stopper layer 3, the thickness of the first nozzle layer 1 is constant and there is no variation in flow resistance.

  In addition, the manufacturing method of the nozzle plate 8 (80) in the above embodiment includes the step of attaching the first nozzle layer 1 (nozzle layer 10) and the stopper layer 3 (on the first nozzle layer 1 (nozzle layer 10)). 30), the step of forming an opening in the stopper layer 3 (30), and the shape of the opening formed in the stopper layer 3 (30) as a mask, the first nozzle hole 11a (110a) is processed. A process and the process of separating the 1st nozzle layer 1 (nozzle layer 10) and a support substrate can also be provided.

  In the manufacturing method of the nozzle plate 8 (80) configured as described above, when the opening of the stopper layer 3 (30) serving as a mask for the first nozzle hole 11a (110a) is formed, the first nozzle layer 1 (nozzle layer 10) is formed. Since the opening is supported by the support substrate, the opening can be processed with high accuracy. For this reason, the first nozzle hole 11a (110a) for processing using the opening as a mask is formed with high accuracy.

  In addition, the manufacturing method of the nozzle plate in the said embodiment can also be characterized by processing the said 1st nozzle hole 11a or the 2nd nozzle hole 11b using dry etching.

  In the manufacturing method of the nozzle plate 8 having the above-described configuration, the first nozzle hole 11a or the second nozzle hole 11b is processed by etching having high anisotropy. Can be processed.

  In all the embodiments described above, the shielding layer is processed into a predetermined outer shape in order to reduce deformation due to stress of the nozzle plate. However, in the gist of the present invention, the outer shape of the shielding layer is changed to the nozzle. It is also possible to have a shape that covers almost the entire surface of the nozzle plate without processing each hole.

  The method for manufacturing a nozzle plate according to the present invention is a method for manufacturing a nozzle plate having at least one nozzle hole for discharging a liquid substance in order to solve the above problem, and a step of preparing a sacrificial member; Forming a first nozzle layer on the sacrificial member; processing a nozzle hole in the first nozzle layer; etching the sacrificial member after the nozzle hole processing; and the first nozzle layer and the sacrificial member It can also comprise so that the process of separating may be provided.

  In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention is configured such that the sacrificial member includes a substrate and a layered member formed on the substrate. You can also.

  In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention is the above-described nozzle plate manufacturing method, wherein the first nozzle layer is formed on the first nozzle layer with respect to the nozzle hole etching processing means. A step of forming a shielding layer having higher etching resistance, a step of forming a through hole in the shielding layer, a step of etching the first nozzle hole using the through hole shape formed in the shielding layer as a mask, It may be configured to include a step of separating the first nozzle layer and the substrate by etching the sacrificial member.

  In order to solve the above problems, a method for manufacturing a nozzle plate according to the present invention includes a step of preparing a sacrificial member and a step of forming a first nozzle layer on the sacrificial member in the method of manufacturing a nozzle plate. Then, a shielding layer having higher etching resistance than the first nozzle layer and the second nozzle layer is formed on the first nozzle layer with respect to the etching processing means for the first nozzle hole and the second nozzle hole. A step of forming a through hole in the shielding layer, a step of etching the first nozzle hole using the shape of the through hole formed in the shielding layer as a mask, and on the first nozzle layer or the shielding layer Forming a second nozzle layer, etching a second nozzle hole reaching the shielding layer from the second nozzle layer surface, and etching the sacrificial member. By ring may be configured to include the step of separating the first nozzle layer and the substrate.

  In order to solve the above problems, a method for manufacturing a nozzle plate according to the present invention includes a step of etching the second nozzle hole in the method for manufacturing a nozzle plate, and an etching process for the first nozzle hole. It is also possible to configure so that the steps to be performed are continuously performed in this order by the same etching apparatus.

  In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention includes a step of forming a through hole of a shielding layer to be a mask pattern of a first nozzle hole in the method for manufacturing a nozzle plate, A step of bonding a reinforcing plate to the first nozzle layer or the shielding layer; and a step of etching the sacrificial member after the reinforcing plate is bonded to separate the first nozzle layer from the substrate. You can also.

  In order to solve the above-described problem, the nozzle plate manufacturing method according to the present invention may be configured such that the sacrificial member is etched using an acid or alkaline solution in the nozzle plate manufacturing method. .

In order to solve the above-described problem, a method for manufacturing a nozzle plate according to the present invention provides a sacrificial member at least partially made of a material mainly composed of Ni, Cu, or Al in the above-described nozzle plate manufacturing method. A step, a step of forming a first nozzle layer or a second nozzle layer made of polyimide or a material mainly containing at least one of Si, SiO ₂ , and Si ₃ N ₄ , Ti, W, _{nb, Au, Pt, SiO 2} , Si 3 N 4, a step of forming a shielding layer mainly one or more of the Al ₂ O _3, the sacrificial member with an aqueous solution containing nitric acid or potassium hydroxide And a step of etching the substrate.

  In order to solve the above-described problem, the nozzle plate manufacturing method according to the present invention may be configured such that the sacrificial member is etched using plasma containing oxygen in the nozzle plate manufacturing method. it can.

In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention includes a step of preparing a sacrificial member made of a material mainly composed of polyimide in at least a part of the nozzle plate manufacturing method, and Si , Forming a first nozzle layer or a second nozzle layer made of a material mainly containing at least one of SiO ₂ and Si ₃ N ₄ , Al, Cu, Ni, Fe, Co, And a step of forming a shielding layer mainly composed of one or more of Au, Pt, and Al ₂ O ₃ and a step of etching the sacrificial member using oxygen-containing plasma. You can also.

  In order to solve the above-described problem, a nozzle plate manufacturing method according to the present invention is the above nozzle plate manufacturing method, wherein the nozzle plate is simultaneously processed during the first nozzle hole processing or the second nozzle hole processing. It can also comprise so that external shape processing may be performed.

  Finally, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and technical means disclosed in different embodiments are appropriately combined. Embodiments obtained in this manner are also included in the technical scope of the present invention.

  It is possible to create a nozzle plate having a plurality of droplet discharge ports stably without damaging the droplet discharge ports in the nozzle manufacturing process, with a first nozzle hole with high formation accuracy, and a fine pattern with minute dots It can also be applied to the use of a fine dot forming apparatus for forming the.

(A) is a perspective view which shows the nozzle plate concerning Embodiment 1 of this invention, (b) is explanatory drawing which shows the A-A 'arrow cross section of (a). It is explanatory drawing which shows the modification of the said nozzle plate by the structure of a cross section. (A)-(g) is explanatory drawing which shows the manufacturing method of the nozzle plate concerning Embodiment 1 of this invention by the structure of a cross section. It is explanatory drawing which shows the modification of the manufacturing method of the said nozzle plate by the structure of a cross section. (A) is a perspective view which shows the nozzle plate concerning Embodiment 2 of this invention, (b) is explanatory drawing which shows the B-B 'arrow cross section in (a). (A)-(g) is explanatory drawing which shows the manufacturing method of the nozzle plate concerning Embodiment 2 of this invention by the structure of a cross section. FIG. 6 is a perspective view illustrating a configuration of a reinforcing plate according to a second embodiment. (A)-(c) is explanatory drawing which shows the other manufacturing method of the nozzle plate concerning Embodiment 1 of this invention by the structure of a cross section. It is explanatory drawing which shows the other manufacturing method of the nozzle plate concerning Embodiment 1 of this invention by the structure of a cross section. (A) (b) is a schematic diagram explaining the joining method of a nozzle layer and a reinforcement board. (A) is a perspective view which shows the conventional nozzle plate, (b) is explanatory drawing which shows the C-C 'arrow cross section in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st nozzle layer 2 2nd nozzle layer 3, 30 Stopper layer (shielding layer)
4, 40 Liquid repellent film 5, 50 Sacrificial layer 51, 510 Substrate 6, 60 Sacrificial member 8, 80 Nozzle plate 10 Nozzle layer 20 Reinforcing plates 11a, 110a First nozzle holes 11b, 110b Second nozzle holes

Claims (9)

A method for producing a nozzle plate having at least one nozzle hole for discharging a liquid substance,
Preparing a sacrificial member comprising a substrate and a sacrificial layer formed on the substrate;
Forming a first nozzle layer on the sacrificial layer;
Forming a shielding layer having a higher etching resistance to the first etching processing means than the first nozzle layer on the formed first nozzle layer;
After forming the shielding layer, etching the through hole in the shielding layer by the second etching means;
Forming the second nozzle layer on the shielding layer and on the first nozzle layer where the shielding layer is not formed, after forming the through hole;
Forming a second nozzle hole in the formed second nozzle layer by etching from the second nozzle layer surface to reach the shielding layer; and
Etching the first nozzle hole by the first etching means using the shielding layer in which the through hole is formed as a mask;
After the first nozzle hole and the second nozzle hole by etching, and characterized in that it comprises by etching the sacrificial layer, and a step of separating the substrate and the first nozzle layer A method for manufacturing a nozzle plate. A step of etching the second nozzle holes, according to the first nozzle hole and the step of etching, in claim 1, characterized in that continuously performed in the same etching apparatus in this order Manufacturing method of nozzle plate.   The shielding layer has higher etching resistance with respect to the first etching processing means than the first nozzle layer, and an etching rate with respect to the second etching processing means is similar to that of the first nozzle layer. The method for manufacturing a nozzle plate according to claim 1. 2. The method of manufacturing a nozzle plate according to claim 1, wherein the sacrificial layer is etched using an acid or alkaline solution. Preparing a sacrificial layer at least partially of a material mainly composed of Ni, Cu, or Al;
Forming a first nozzle layer or a second nozzle layer made of polyimide or a material mainly composed of at least one of Si, SiO ₂ , and Si ₃ N ₄ ;
Forming a shielding layer mainly composed of one or more of Ti, W, Nb, Au, Pt, SiO ₂ , Si ₃ N ₄ , and Al ₂ O ₃ ;
And a step of etching the sacrificial layer with an aqueous solution containing nitric acid or potassium hydroxide. 2. The method for manufacturing a nozzle plate according to claim 1, wherein the etching of the sacrificial layer is performed using plasma containing oxygen. A step of preparing a sacrificial layer at least partially made of a material mainly composed of polyimide;
Forming a first nozzle layer or a second nozzle layer made of a material mainly composed of at least one of Si, SiO ₂ , and Si ₃ N ₄ ;
Forming a shielding layer mainly composed of one or more of Al, Cu, Ni, Fe, Co, Au, Pt, and Al ₂ O ₃ ;
And a step of etching the sacrificial layer using a plasma containing oxygen.   2. The nozzle plate manufacturing method according to claim 1, wherein the outer shape processing of the nozzle plate is performed at the same time as the first nozzle hole processing. 2. The nozzle plate manufacturing method according to claim 1 , wherein the outer shape processing of the nozzle plate is performed at the same time as the second nozzle hole processing.

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