JP2013163270A - Method for manufacturing nozzle plate, and method for manufacturing liquid ejecting head - Google Patents

Abstract

An object of the present invention is to prevent variation in the opening diameter of an ink discharge side of a first nozzle portion when a multi-stage nozzle hole is formed in which a first nozzle portion having a small diameter and a second nozzle portion having a large diameter communicate with each other. Further, it is possible to provide a method for manufacturing a nozzle plate and a method for manufacturing a droplet discharge head, which can form the first nozzle portion and the second nozzle portion with high positional accuracy.
In manufacturing a nozzle plate for a droplet discharge head, a first surface 100a of a substrate 100 is etched to form a first recess 12a for forming a first nozzle portion, and then a second surface 100b of the substrate 100 is formed. The substrate 100 is thinned from the side to form the first recess 12a as the through hole 12b. Next, the second surface 100b of the substrate 100 is etched to form a second recess 14a for forming a second nozzle portion having a diameter larger than that of the through hole 12b in a region overlapping with the through hole 12b.
[Selection] Figure 5

Description

  The present invention relates to a method for manufacturing a nozzle plate and a method for manufacturing a droplet discharge head.

  A droplet discharge device such as an ink jet printer has many advantages such as extremely low noise during recording, high-speed printing, and use of inexpensive plain paper with a high degree of freedom of ink. In addition, the so-called ink-on-demand method, which ejects ink droplets only when recording is necessary, is becoming mainstream because it does not require collection of ink droplets that are not necessary for recording. . Ink jet heads (droplet discharge heads) used in such ink-on-demand ink jet printers use an electrostatic force as a driving means, a piezoelectric method using a piezoelectric element, heat generation as a method for discharging ink droplets. There is a bubble jet (registered trademark) system using an element.

  Ink jet heads generally have a structure in which a cavity plate is joined to a nozzle plate in which a plurality of nozzle holes for discharging ink droplets are formed. The cavity plate is formed with an ink flow path such as a discharge chamber or a reservoir communicating with the nozzle hole, and ink droplets are discharged from the selected nozzle hole by applying pressure to the discharge chamber by the driving means.

  In the inkjet head, as a method of improving the ejection characteristics, a method of adjusting the flow path resistance of the nozzle hole and adjusting the thickness of the substrate so as to obtain an optimum nozzle length has been proposed. In addition, instead of making the nozzle hole as an integral cylindrical shape as a whole, it has a two-stage nozzle shape composed of a first nozzle portion having a small diameter (ink ejection side) and a second nozzle portion having a large diameter (ink supply side), It has been proposed to align the direction of ink pressure applied to the nozzle in the nozzle axis direction (see Patent Documents 1 and 2).

  As a method of manufacturing a nozzle plate having such a multi-stage nozzle hole, in Patent Document 1, after deeply etching one surface side (ink supply side) of a substrate to form a first recess for forming a first nozzle portion Then, the one surface side of the substrate is etched shallowly to form a second recess for forming the second nozzle portion, and then the substrate is thinned by polishing from the other surface side (ink ejection side) of the substrate. A method is employed in which the first nozzle portion is formed by penetrating the recess.

  Also, in Patent Document 2, after etching one side (ink ejection side) of the substrate to form the first recess for forming the first nozzle portion, the thin plate of the substrate is formed from the other side (ink supply side) of the substrate. Then, the substrate is etched from the other side of the substrate to form a second recess for forming the second nozzle portion, and the first nozzle portion is formed by penetrating the first recess. Has been.

JP 2007-168344 A JP 2010-240852 A

  However, in the manufacturing method described in Patent Document 1, when the substrate is thinned by polishing from the other side (ink discharge side) of the substrate, the opening edge on the ink discharge side of the first nozzle portion may be missing. . Although there is a method of thinning the substrate by etching the other surface side of the substrate, in such a method, the opening edge on the ink discharge side of the first nozzle portion is also etched. As a result, the manufacturing method described in Patent Document 1 has a problem in that the opening diameter of the first nozzle portion on the ink discharge side varies and the discharge characteristics deteriorate.

  In the manufacturing method described in Patent Document 2, the first recess for forming the first nozzle portion is formed by etching from one surface of the substrate, and the second recess for forming the second nozzle portion is etched from the other surface of the substrate. Therefore, when the etching mask is formed by the photolithography technique, alignment of the exposure mask on one side of the substrate and alignment of the exposure mask on the other side of the substrate are performed. For this reason, there is a problem in that the accuracy of the relative position or the like between the first recess (first nozzle portion) and the second recess (second nozzle portion) is low, and as a result, the discharge characteristics deteriorate.

  In view of the above problems, an object of the present invention is to form a multistage nozzle hole in which a first nozzle portion having a small diameter and a second nozzle portion having a large diameter communicate with each other. It is an object of the present invention to provide a method for manufacturing a nozzle plate and a method for manufacturing a droplet discharge head that can prevent the opening diameter of the nozzle from varying.

  Another object of the present invention is to provide a method for manufacturing a nozzle plate and a method for manufacturing a droplet discharge head, which can form a first nozzle portion having a small diameter and a second nozzle portion having a large diameter with high positional accuracy. It is to provide.

  In order to solve the above-described problem, in the method for manufacturing a nozzle plate according to the present invention, when a plurality of main surfaces of a flat substrate are respectively a first surface and a second surface, the first surface is formed on the first surface. Etching the first surface with an etching mask to form a first recess for forming a first recess for forming the first nozzle portion; and thinning the substrate from the second surface toward the first surface. The thinning step using the first recess as a through hole and the second surface is etched with a second etching mask formed on the second surface, and the through hole is overlapped with the through hole in a plan view. And a second recess forming step for forming a second recess for forming the second nozzle portion having a diameter larger than that of the hole.

  In the present invention, in the first recess forming step, the first surface of the substrate is etched to form the first recess for forming the first nozzle portion, and then in the thinning step, the substrate is thinned from the second surface side. The first recess is a through hole. Next, in the second recess formation step, the second surface of the substrate is etched to form a second recess for forming the second nozzle portion having a larger diameter than the through hole in a region overlapping the through hole in plan view. As a result, it is possible to manufacture a nozzle plate having a nozzle hole in which a first nozzle portion having a small diameter and a second nozzle portion having a large diameter communicate with each other, and the first surface side of the nozzle plate is used as an ink discharge side. . Here, the first nozzle portion opens on the ink discharge side, but the ink discharge side (first surface side) is located on the side opposite to the side to be thinned. For this reason, the opening edge on the ink discharge side of the first nozzle portion is not chipped or melted by etching during the thinning process, so that the opening diameter on the ink discharge side of the first nozzle portion is prevented from varying. be able to. Therefore, a nozzle plate excellent in discharge performance can be realized.

  In the present invention, in the second recess forming step, in the photolithography for forming the second etching mask, the exposure mask is aligned based on the through hole or the alignment through hole formed simultaneously with the through hole. It is preferable. According to such a configuration, the first nozzle portion having a small diameter and the second nozzle portion having a large diameter can be formed with high positional accuracy. That is, in the present invention, in the first recess forming step, the first surface of the substrate is etched to form the first recess for forming the first nozzle portion, and in the second recess forming step, the second surface of the substrate is etched. Then, the second concave portion for forming the second nozzle portion is formed. When the second concave portion forming step is performed, the first concave portion becomes a through hole and is opened on the second surface side. Therefore, in the photolithography process for forming the second etching mask in the second recess forming process, the alignment of the exposure mask can be performed with reference to the through hole or the alignment through hole formed simultaneously with the through hole. Accordingly, since the first nozzle portion with a small diameter and the second nozzle portion with a large diameter can be formed with high positional accuracy, a nozzle plate with excellent discharge performance can be realized.

  In the present invention, in the second recess forming step, the first surface and one main surface of the support member are surface bonded, and the cooling gas is applied to the other main surface of the support member that is not surface bonded. It is preferable to dry-etch the second surface while supplying. According to this configuration, the substrate can be cooled during dry etching, so that the shape of the second recess is stabilized. Moreover, since the opening part of the through-hole formed in the board | substrate is obstruct | occluded with the supporting member, the gas for cooling does not leak to the 2nd surface side which is performing dry etching. Therefore, dry etching can be suitably performed.

  In the present invention, it is preferable that the substrate is ground or polished from the second surface toward the first surface in the thinning step. In the thinning process, if grinding or polishing is performed on the substrate from the second surface side, the opening edge of the through hole may be chipped. In the present invention, grinding or polishing processing is performed on the second surface side. Since it is performed on the side opposite to the ink discharge side, even if a chip occurs, the discharge performance is not greatly affected.

  The method for manufacturing a nozzle plate according to the present invention can be applied to a method for manufacturing a droplet discharge head. According to such a configuration, it is possible to realize a droplet discharge head having excellent discharge performance.

It is a disassembled perspective view of the droplet discharge head to which the present invention is applied. FIG. 2 is a longitudinal sectional view of a main part of the droplet discharge head shown in FIG. 1. It is a top view of the board | substrate used for manufacture of the nozzle plate shown in FIG. It is process sectional drawing which shows the manufacturing method of the nozzle plate shown in FIG. It is process sectional drawing which shows the manufacturing method of the nozzle plate performed following FIG. It is process sectional drawing which shows the manufacturing method of the nozzle plate performed following FIG. It is a perspective view of a droplet discharge device provided with a droplet discharge head to which the present invention is applied.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, an ink jet printer is exemplified as a liquid droplet ejection apparatus to which the present invention is applied, an ink jet head of an ink jet printer is illustrated as a liquid droplet ejection head to which the present invention is applied, and a nozzle plate to which the present invention is applied. As an example, a nozzle plate for an inkjet head will be described.

(Configuration of the droplet discharge head of the droplet discharge device)
FIG. 1 is an exploded perspective view of a droplet discharge head to which the present invention is applied. FIG. 2 is a longitudinal sectional view of the main part of the droplet discharge head shown in FIG. 1, and FIGS. 2A and 2B are a longitudinal sectional view of the droplet discharge head and an enlarged nozzle hole of the nozzle plate. It is a longitudinal cross-sectional view shown.

  1 and 2, a droplet discharge head 10 of this embodiment is an inkjet head of an inkjet printer, and includes a nozzle plate 1 in which a plurality of nozzle holes 11 are linearly provided at predetermined intervals, and each nozzle hole 11. On the other hand, the cavity plate 2 provided with the ink supply path independently and the electrode substrate 3 facing the vibration plate 22 of the cavity plate 2 are bonded together. In this embodiment, the nozzle holes 11 are arranged in two lines in a straight line, and, for example, 360 nozzle holes 11 are formed in one line.

In this embodiment, the nozzle plate 1 is made of, for example, a silicon substrate having a thickness of about 65 μm, and the nozzle hole 11 has a nozzle portion formed in a two-stage cylindrical shape having different diameters. More specifically, the nozzle hole 11 is located on the ink discharge surface 1a side, a small-diameter first nozzle portion (a small-diameter hole in the ejection port portion) 11a whose tip is opened on the ink discharge surface 1a, the cavity plate 2, It is composed of a large-diameter second nozzle portion (large-diameter hole in the introduction port portion) 11b that is located on the joining surface 1b side to be joined and has an introduction port portion that opens at the joining surface 1b, and includes the first nozzle portion 11a and the second nozzle portion. The nozzle portion 11b is provided perpendicular to the substrate surface and coaxially. For this reason, the discharge direction of the ink droplets can be aligned with the central axis direction of the nozzle hole 11, so that stable ink discharge characteristics are exhibited. As a result, variations in the flying direction of ink droplets and ink droplets can be prevented from scattering. In this embodiment, a liquid-resistant protective film 18 made of a SiO ₂ film or the like is formed on the surface of the nozzle plate 1. A liquid repellent layer 19 having liquid repellency with respect to ink is formed around the nozzle hole 11 on the ink ejection surface 1 a side of the nozzle plate 1. In this embodiment, the inner diameter of the first nozzle portion 11a is, for example, 15 to 30 μm, and the inner diameter of the second nozzle portion 11b is about 1.5 times the inner diameter of the first nozzle portion 11a.

  In this embodiment, the cavity plate 2 is made from a silicon substrate. The cavity plate 2 is formed with a pressure chamber recess 210 for configuring the pressure chamber 21, an orifice recess 230 for configuring the orifice 23, and a reservoir recess 240 for configuring the reservoir 24. The pressure chamber recess 210 (pressure chamber 21) and the reservoir recess 240 (reservoir 24) communicate with each other via the orifice recess 230 (orifice 23). The reservoir 24 constitutes a common ink chamber common to the pressure chambers 21, and communicates with the pressure chambers 21 through the orifices 23. An ink supply hole 25 penetrating the cavity plate 2 and the electrode substrate 3 is formed at the bottom of the reservoir 24, and ink is supplied from an ink cartridge (not shown) through the ink supply hole 25. The bottom wall of the pressure chamber 21 is a thin diaphragm 22. Note that an insulating film 26 such as a silicon oxide film formed by thermal oxidation or plasma CVD (Chemical Vapor Deposition) is formed on the entire surface of the cavity plate 2 or at least the surface facing the electrode substrate 3. Such an insulating film 26 prevents dielectric breakdown or short circuit when the droplet discharge head 10 is driven.

  In this embodiment, the electrode substrate 3 is made of a glass base material. The electrode substrate 3 is provided with a recess 310 at a position facing the diaphragm 22 of the cavity plate 2, and inside the recess 310 is made of ITO (Indium Tin Oxide) or the like. Individual electrodes 31 are formed by sputtering. Therefore, the gap formed between the diaphragm 22 and the individual electrode 31 is determined by the depth of the recess 310, the thickness of the individual electrode 31, and the thickness of the insulating film 26 that covers the diaphragm 22. Become.

  The individual electrode 31 includes a lead portion 31a and a terminal portion 31b connected to a flexible wiring board (not shown). The terminal part 31b is located in the electrode extraction part 311 exposed from the end part of the cavity plate 2 for wiring. The terminal portions 31b of the individual electrodes 31 and the common electrode 27 of the cavity plate 2 are electrically connected to a drive control circuit 4 such as an IC driver.

(Operation of the droplet discharge head 10)
In the droplet discharge head 10, when the drive control circuit 4 supplies a positive charge to the individual electrode 31 of the droplet discharge head 10, the diaphragm 22 is negatively charged, and the individual electrode 31 and the diaphragm 22 are charged. Electrostatic force is generated during Due to the electrostatic force, the diaphragm 22 is attracted to the individual electrode 31 and bent. As a result, the volume of the pressure chamber 21 increases, and the ink accumulated in the reservoir 24 flows into the pressure chamber 21 through the orifice 23. Next, when the supply of electric charges to the individual electrode 31 is stopped, the electrostatic attractive force disappears, and the diaphragm 22 returns to its original state by the elastic force. At that time, the volume of the pressure chamber 21 is rapidly decreased, the pressure in the pressure chamber 21 is rapidly increased, and a part of the ink in the pressure chamber 21 is ejected from the nozzle hole 11 as an ink droplet. Thereafter, the above operation is repeated.

(Manufacturing method of the droplet discharge head 10)
A method of manufacturing the droplet discharge head 10 shown in FIG. 1 will be described with reference to FIGS. FIG. 3 is a plan view of the substrate 100 used for manufacturing the nozzle plate 1 shown in FIG. FIG. 4 is a process cross-sectional view showing a method for manufacturing the nozzle plate 1 shown in FIG. FIG. 5 is a process cross-sectional view illustrating a method for manufacturing the nozzle plate 1 performed subsequent to FIG. 4. FIG. 6 is a process cross-sectional view illustrating a nozzle plate manufacturing method performed subsequent to FIG. 5. In the following description, the plurality of main surfaces of the flat substrate 100 are referred to as a first surface 100a and a second surface 100b, respectively. 4 and 6, the first surface 100a and the second surface 100b of the first surface 100a and the second surface 100b are illustrated with the first surface 100a that becomes the ink ejection surface 1a upward when the nozzle plate 1 is formed, and in FIG. A first surface 100a of 100 is shown facing downward.

  In order to manufacture the nozzle plate 1 of the droplet discharge head 10 shown in FIG. 1, first, the substrate 100 shown in FIG. 3 is prepared. The substrate 100 is, for example, a silicon substrate having a thickness of 280 μm, and the nozzle holes 11 and the like are formed in each of a plurality of regions surrounded by a dicing line indicated by a one-dot chain line L1 by performing each process described below. After that, when the substrate 100 is cut along the dicing line, the plurality of nozzle plates 1 are cut out.

In this embodiment, first, in the first recess forming step shown in FIGS. 4A and 4B, the first surface 100 a of the substrate 100 is formed with the first etching mask 41 formed on the first surface 100 a of the substrate 100. Etching is performed to form the first recess 12a for forming the first nozzle portion. More specifically, as shown in FIG. 4A, after the photosensitive resist 40 is applied to the first surface 100a of the substrate 100, the photosensitive resist 40 is exposed through the exposure mask 42 in the photolithography process. Then, develop. As a result, a first etching mask 41 made of a resist mask is formed. In such a photolithography process, the exposure mask 42 is aligned with reference to an alignment mark (not shown) formed on the first surface 100a of the substrate 100, for example. Next, as shown in FIG. 4B, the first surface 100a of the substrate 100 is etched through the opening 41a of the first etching mask 41, and the first recess 12a for forming the first nozzle portion is formed. Form deeply. In this embodiment, as this etching, anisotropic dry etching is performed on the first surface 100a of the substrate 100 by an ICP dry etching apparatus (not shown) to form the first recess 12a perpendicular to the first surface 100a. To do. As an etching gas in this case, C ₄ F ₈ gas and SF ₆ gas are used, and these etching gases are used alternately. Here, the C ₄ F ₈ gas is used to protect the side surface so that the etching does not proceed to the side surface of the first recess 12a, and the SF ₆ gas is used to promote the etching of the substrate 100 in the vertical direction. use.

  In this embodiment, when dry etching is performed on the first surface 100 a of the substrate 100, the second surface 100 b side of the substrate 100 is held by the electrostatic chuck device 70, and the air hole 71 of the electrostatic chuck device 70 is interposed. Then, dry etching is performed while cooling the substrate 100 by supplying a cooling gas such as helium gas (He gas) to the substrate 100. Accordingly, the shape of the first recess 12a is stabilized.

Next, as shown in FIG. 4C, after removing the first etching mask 41 by sulfuric acid cleaning or the like, a protective film 13 is formed on the entire surface of the substrate 100 as shown in FIG. More specifically, the substrate 100 is set in a thermal oxidation apparatus (not shown), and the substrate 100 is subjected to a thermal oxidation process under conditions of an oxidation temperature of 1075 ° C., an oxidation time of 4 hours, and a mixed atmosphere of oxygen and water vapor, A protective film 13 made of a SiO ₂ film having a thickness of 1 μm is formed on the entire surface of the substrate 100.

  Next, as illustrated in FIG. 4E, one of the two main surfaces of the support member 50 is surface-bonded to the first surface 100 a side of the substrate 100. In this embodiment, the support member 50 is made of a protective tape that is attached to the first surface 100a side of the substrate 100 via an adhesive layer. As the protective tape, for example, a tape provided with a self-peeling layer on the surface of the adhesive layer can be used, and the self-peeling layer has a lower adhesive force due to stimuli such as ultraviolet rays or heat. Accordingly, when the protective tape is peeled off, the protective tape can be easily peeled off from the substrate 100 by applying a stimulus such as ultraviolet rays or heat.

  Next, in the thinning process illustrated in FIG. 5F, the substrate 100 from the second surface 100 b side of the substrate 100 with the one main surface of the support member 50 being surface-bonded to the first surface 100 a side of the substrate 100. The first recess 12a is formed as a through hole 12b. In performing this thinning process, in this embodiment, the substrate 100 is cleaned after being ground or polished on the second surface 100b side. For example, the second surface 100b of the substrate 100 is ground by a back grinder (not shown), and the substrate 100 is thinned until the bottom of the first recess 12a is opened. In the thinning step, the substrate 100 may be thinned until the second surface 100b is polished by a polisher and a CMP apparatus until the bottom of the first recess 12a is opened.

  Next, in the second recess forming step shown in FIGS. 5G and 5H, the second surface 100b of the substrate 100 is etched with the second etching mask 61 formed on the second surface 100b of the substrate 100. The second recess 14a for forming the second nozzle part having a larger diameter than the through hole 12b is formed in a region overlapping the through hole 12b in plan view. More specifically, as shown in FIG. 5G, after the photosensitive resist 60 is applied to the second surface 100b of the substrate 100, the photosensitive resist 60 is exposed through the exposure mask 62 in the photolithography process. Then, develop. As a result, a second etching mask 61 made of a resist mask is formed.

  In such a photolithography process, the exposure mask 62 is aligned by using a portion of the through hole 12b that is open on the second surface 100b of the substrate 100 as an alignment mark. Alternatively, when forming the first concave portion 12a, for example, as shown in FIG. 3, the alignment concave portion 17a is simultaneously formed in an area or the like cut out as the nozzle plate 1, and the alignment concave portion 17a is used for alignment by a thinning process. The through hole 17b may be opened on the second surface 100b of the substrate 100. According to such a configuration, the alignment of the exposure mask 62 can be performed by using, as the alignment mark, the portion of the alignment through hole 17b that is open on the second surface 100b of the substrate 100.

Next, as shown in FIG. 5 (h), the second surface 100b of the substrate 100 is etched through the opening 61a of the second etching mask 61, and the second recess 14a for forming the second nozzle portion is formed. Form shallow. As this etching, in this embodiment, similarly to the first recess formation step, anisotropic dry etching is performed on the second surface 100b of the substrate 100 by an ICP dry etching apparatus (not shown), and the second recess 14a is formed in the second recess 14a. It is formed perpendicular to the surface 100b. As an etching gas in this case, C ₄ F ₈ gas and SF ₆ gas are used, and these etching gases are used alternately. Here, the C ₄ F ₈ gas is used to protect the side surface so that the etching does not proceed to the side surface of the second recess 14a, and the SF ₆ gas is used to promote the etching of the substrate 100 in the vertical direction. use.

  In this embodiment, when dry etching is performed on the second surface 100b of the substrate 100 in the second recess forming step, the side of the first surface 100a of the substrate 100 (the side on which the support member 50 is attached) is electrostatic chuck. A cooling gas such as helium gas (He gas) is supplied to the other main surface of the support member 50 to which the substrate 100 is not bonded via the vent hole 71 of the electrostatic chuck device 70. Thus, dry etching is performed while the substrate 100 is cooled. Therefore, the shape of the second recess 14a is stabilized.

  Next, as shown in FIG. 5 (i), the support member 50 (protective tape) is stimulated with ultraviolet rays or heat to peel the support member 50 from the substrate 100, and the second etching mask 61 is washed with sulfuric acid or the like. Remove.

  Next, as shown in FIG. 5J, the protective film 13 is wet-etched with a hydrofluoric acid aqueous solution or the like, for example, and the protective film 13 is removed. As a result, a nozzle hole 11 in which the first nozzle portion 11a having a small diameter and the second nozzle portion 11b having a large diameter communicate with each other is formed in the substrate 100.

Next, as shown in FIG. 6K, a liquid-resistant protective film 18 having ink resistance is formed on the entire surface of the substrate 100 including the inner wall of the nozzle hole 11. In this embodiment, the substrate 100 is put into a thermal oxidation furnace, and a thermal oxide film (SiO ₂ film) having a film thickness of, for example, 0.1 μm is formed as the liquid-resistant protective film 18 on the entire surface of the substrate 100.

Next, a liquid repelling process is performed to give the substrate 100 liquid repellency with respect to ink. Specifically, as shown in FIG. 6L, a liquid repellent material mainly composed of a silicon compound containing fluorine atoms is formed by vapor deposition or dipping, and a liquid repellent layer 19 is formed on the entire surface of the substrate 100. Form. At this time, the liquid repellent layer 19 is also formed on the inner wall of the nozzle hole 11. And as shown in FIG.6 (m), the state which applied the protective tape 80 to the part which should ensure liquid repellency among the board | substrates 100, ie, the discharge port periphery of the nozzle hole 11 of the 1st surface 100a. After removing the liquid repellent layer 19 by Ar sputtering or O ₂ plasma treatment, the protective tape 80 is peeled off as shown in FIG.

  Although illustration of the subsequent steps is omitted, after applying a dicing tape to the first surface 100a or the second surface 100b of the substrate 100, the substrate 100 is separated into individual nozzle plates 1 by dicing, The nozzle plate 1 is obtained by peeling from the dicing tape.

  In order to manufacture the droplet discharge head 10 using the nozzle plate 1 manufactured as described above, the bonding surface of the cavity plate 2 is bonded to the bonding surface 1b of the nozzle plate 1 as shown in FIG. Thereafter, the bonding surface of the electrode substrate 3 is attached to the other bonding surface of the cavity plate 2. As a result, the droplet discharge head 10 including the joined body of the nozzle plate 1, the cavity plate 2 and the electrode substrate 3 is completed.

(Main effects of this form)
As described above, in this embodiment, in the first recess forming step, the first surface 100a of the substrate 100 is etched to form the first recess 12a for forming the first nozzle portion, and then in the thinning step, the substrate The first concave portion 12a is formed as a through hole 12b by thinning from the second surface 100b side of 100. Next, in the second recessed portion forming step, when the second surface 100b of the substrate 100 is etched to form the second recessed portion 14a for forming the second nozzle portion having a larger diameter than the through hole 12b in the region overlapping the through hole 12b, A nozzle plate 1 having a nozzle hole 11 in which a first nozzle portion 11a having a small diameter and a second nozzle portion 11b having a large diameter communicate with each other can be manufactured. Used as the ink ejection surface 1a side. Here, the first nozzle portion 11a opens on the ink ejection surface 1a side, but the ink ejection surface 1a side (first surface 100a side) is located on the opposite side to the side where the thinning is performed. For this reason, the opening edge on the ink discharge side of the first nozzle portion 11a is not chipped when thinned by grinding or polishing, so that the opening diameter on the ink discharge side of the first nozzle portion 11a varies. Can be prevented. Therefore, the nozzle plate 1 excellent in discharge performance can be realized.

  Further, in the photolithography process for forming the second etching mask 61 in the second recess forming process, the alignment of the exposure mask 62 is performed with reference to the through hole 12b or the alignment through hole 17b formed simultaneously with the through hole 12b. Do. For this reason, the small-diameter first nozzle part 11a and the large-diameter second nozzle part 11b can be formed with high positional accuracy. That is, when performing a 2nd recessed part formation process, the 1st recessed part 12a becomes the through-hole 12b, and is opened by the 2nd surface 100b side. Accordingly, in the photolithography process for forming the second etching mask 61 in the second recess forming process, the exposure mask 62 is aligned with reference to the through hole 12b or the alignment through hole 17b formed simultaneously with the through hole 12b. It can be carried out. Accordingly, since the first nozzle portion 11a having a small diameter and the second nozzle portion 11b having a large diameter can be formed with high positional accuracy, the nozzle plate 1 having excellent discharge performance can be realized.

For example, the variation S1 in the opening diameter of the first nozzle portion 11a in the nozzle plate 1 according to the present embodiment, the variation S2 in the coaxiality between the first nozzle portion 11a and the second nozzle portion 11b, and the variation S3 in the position of the nozzle hole 11 are obtained. As a result of measurement by an electron micrograph, the following values were obtained.
S1 = ± 0.1 μm
S2 = ± 0.2 μm
S3 = ± 0.1μm or less

On the other hand, as described in Patent Document 1, after deeply etching one surface of the substrate to form the first recess for forming the first nozzle portion, the first surface of the substrate is etched shallowly. The above values S1 and S2 in the case where the manufacturing method according to Reference Example 1 in which the second concave portion for forming the two nozzle portions is formed and then the first concave portion is penetrated by thinning from the other surface side of the substrate is adopted. , S3 had the following values.
S1 = ± 0.3 μm
S2 = ± 0.2 μm
S3 = ± 0.3μm or less

Further, as described in Patent Document 2, after etching one side of the substrate to form the first recess for forming the first nozzle portion, the substrate is thinned from the other side of the substrate, and then Etching the substrate from the other surface side of the substrate to form the second recess for forming the second nozzle portion, and the value S1 in the case of employing the manufacturing method according to Reference Example 2 that penetrates the first recess, S2 and S3 were the following values.
S1 = ± 0.1 μm
S2 = ± 0.4 μm
S3 = ± 0.1μm or less

  Further, in this embodiment, in the second recess forming step, the cooling gas from the side opposite to the substrate 100 with respect to the support member 50 side in a state where the support member 50 is surface-bonded to the first surface 100 a side of the substrate 100. Is dry-etched on the second surface 100b side. For this reason, since the substrate 100 can be cooled during dry etching, the shape of the second recess 14a is stabilized. Further, since the opening of the through hole 12b formed in the substrate 100 is closed by the support member 50, the cooling gas does not leak to the second surface 100b side where dry etching is performed. Therefore, dry etching can be suitably performed.

  Furthermore, in this embodiment, the substrate 100 is ground or polished from the second surface 100b side in the thinning step. In such a configuration, the opening edge of the through hole 12b may be chipped. However, in this embodiment, grinding and polishing are performed on the second surface 100b side (the side opposite to the ink ejection side). Therefore, even if chipping occurs, the discharge performance is not greatly affected.

[Other embodiments]
In the above embodiment, the substrate 100 is thinned by grinding or polishing, but the substrate 100 may be thinned using dry etching. For example, after removing the protective film 13 made of the SiO ₂ film from the second surface 100b of the substrate 100 by dry etching using an etching gas such as CF ₄ gas or CHF ₃ gas in the state shown in FIG. The second surface 100b of the substrate 100 may be etched by dry etching using ₆ gas as an etching gas until the bottom of the first recess 12a is opened.

  In the said embodiment, although the 2nd recessed part 14a was formed by anisotropic dry etching, you may form the 2nd recessed part 14a by isotropic dry etching.

  In the above embodiment, the manufacturing method of the nozzle plate 1 of the ink jet head using the electrostatic force as the driving means has been described. However, the present invention is not limited to the above embodiment, and the technical idea of the present invention. Various modifications can be made within the range of

  For example, the present invention may be applied to the nozzle plate 1 of the droplet discharge head 10 that uses a piezoelectric element, a heating element, or the like as a driving unit. Further, by changing the liquid material discharged from the nozzle hole 11, it can be applied to other droplet discharge devices and devices in addition to the droplet discharge head 10 of the inkjet printer 200 shown in FIG.

1 .... Nozzle plate, 2 .... Cavity plate, 3 .... Electrode substrate, 1a..Ink discharge surface, 1b..Joint surface, 10..Droplet discharge head, 11..Nozzle hole, 11a..First Nozzle part, 11b .. second nozzle part, 12a .. first recess, 12b .. through hole, 14a .. second recess, 17a .. alignment recess, 17b .. alignment through hole, 18. Liquid protective film, 19 ... Liquid repellent layer, 21 ... Pressure chamber, 22 ... Vibration plate, 23 ... Orifice, 24 ... Reservoir, 25 ... Ink supply hole, 41 ... First etching mask, 42 ... .. Exposure mask, 50 .. Support member, 61 .. Second etching mask, 62 .. Exposure mask, 70 .. Electrostatic chuck device, 71 .. Ventilation hole, 100 .. Substrate, 100 a. 100b ... second side, 200 ... Ink-jet printer

Claims (5)

When the plurality of main surfaces of the flat substrate are respectively the first surface and the second surface,
A first recess forming step of forming the first recess for forming the first nozzle portion by etching the first surface with the first etching mask formed on the first surface;
Thinning the substrate from the second surface toward the first surface and using the first recess as a through hole;
A second recess for forming a second nozzle part having a larger diameter than the through hole in a region overlapping the through hole in a plan view by etching the second surface with a second etching mask formed on the second surface A second recess forming step for forming
A method for producing a nozzle plate, comprising:   In the second recess forming step, in the photolithography for forming the second etching mask, the alignment of the exposure mask is performed with reference to the through hole or the alignment through hole formed simultaneously with the through hole. The method for manufacturing a nozzle plate according to claim 1. In the second recess forming step, the first surface and one main surface of the support member are surface bonded,
3. The method of manufacturing a nozzle plate according to claim 1, wherein the second surface is dry-etched while supplying a cooling gas to the other main surface of the support member that is not surface-bonded.   4. The nozzle plate according to claim 1, wherein, in the thinning step, the substrate is ground or polished from the second surface toward the first surface. 5. Production method.   A method for manufacturing a droplet discharge head, wherein the droplet discharge head is manufactured by applying the method for manufacturing a nozzle plate according to any one of claims 1 to 4.

Images