JP2007253373A - Liquid droplet discharge head, liquid droplet discharge apparatus, method for manufacturing liquid droplet discharge head, and method for manufacturing liquid droplet discharge apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid droplet discharge head and the like capable of measuring highly accurately a nozzle pattern, and equipped with a nozzle substrate for a high density liquid droplet discharge head using a silicon single crystal substrate. <P>SOLUTION: The liquid droplet discharge head 10 is equipped with a nozzle hole 11 for discharging liquid droplets, a discharge room 21 for communicating with the nozzle hole 11, a liquid feeding part 24 for feeding a liquid to the discharge room 21, a vibrating plate 22 formed on a part of a wall face 1a of the discharge room 21, and an individual electrode 31 arranged by opposing the vibrating plate 22, and prepared by laminating a plurality of substrates 1, 2 and 3. On one 1 of the substrates, dummy patterns A and B for measuring the hole diameter or the hole length of the nozzle hole 11 are provided with the nozzle hole 11. These dummy patterns A and B are provided on the inner wall 1a side of one substrate 1. The dummy patterns A and B can be formed into the same shape as the shape of the nozzle hole 11. The hole diameters of the dummy patterns A and B can be formed larger than the hole diameter of the nozzle diameter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a droplet discharge head, a droplet discharge device, a method for manufacturing a droplet discharge head, and a method for manufacturing a droplet discharge device.

  As a droplet discharge head for discharging droplets, for example, an inkjet head mounted on an inkjet recording apparatus is known. The ink-jet head has many advantages such as extremely low noise during recording, high-speed printing, and use of inexpensive plain paper with a high degree of ink freedom. Among them, a so-called ink-on-demand system that discharges ink droplets only when recording is necessary does not require collection of ink droplets that are not necessary for recording, and is now mainstream. Ink-on-demand ink jet heads include a method using an electrostatic force as a driving means and a method using a piezoelectric vibrator, a heating element, or the like as a method for ejecting ink.

  Ink jet heads generally include a nozzle substrate in which a plurality of nozzle holes for discharging ink droplets are formed, and an ink such as a discharge chamber and a reservoir that are bonded to the nozzle substrate and communicate with the nozzle holes. And a cavity substrate on which a flow path is formed, and an ink droplet is ejected from a selected nozzle hole by applying pressure to the ejection chamber by a driving unit.

In recent years, there has been an increasing demand for ink jet heads with higher quality such as printing and image quality, and higher density and improved ejection performance have been demanded. For this reason, various devices and proposals have been made for the nozzle portion of the inkjet head.
In such an ink jet head, in order to improve ink ejection characteristics, it is desirable to adjust the flow path resistance of the nozzle portion and adjust the thickness of the substrate so that the optimum nozzle length is obtained.

  When manufacturing such a nozzle substrate, anisotropic dry etching using ICP (Inductively Coupled Plasma) discharge is performed from one surface of the silicon base material, and first recesses having different inner diameters (small diameters serving as injection ports) (Recess) and second recess (large-diameter recess serving as the inlet) are formed in two steps, and then a part of the opposite surface is dug down by anisotropic wet etching to adjust the length of the nozzle hole. (For example, refer to Patent Document 1).

  On the other hand, there is a method in which after a silicon substrate is polished to a desired thickness in advance, dry etching is performed on both sides of the silicon substrate to form an injection port portion and an introduction port portion of the nozzle hole (for example, Patent Documents) 2).

  The accuracy of the nozzle holes of the nozzle substrate formed as described above is an important parameter that affects ink ejection characteristics. Since the radius of the nozzle hole acts as a reciprocal of the fourth power with respect to the flow path resistance and is proportional to the length of the nozzle hole, it is important to increase the accuracy of the nozzle hole diameter and the nozzle length. It is important to measure the nozzle length with high accuracy.

Japanese Patent Laid-Open No. 11-28820 (pages 4-5, FIGS. 3 and 4) Japanese Patent Laid-Open No. 9-57981 (page 2 to page 3, FIGS. 1 and 2)

  However, as the nozzle hole diameter of the nozzle substrate becomes fine, the nozzle hole diameter and the nozzle length may not be measured well, and the yield may be reduced. In addition, when the nozzle hole diameter is measured with an electron microscope such as a length measuring SEM, the silicon oxide film is charged up and the image is blurred, so the nozzle hole diameter and the nozzle length may not be accurately measured.

  The present invention has been made to solve the above-described problems, and includes a nozzle substrate for a high-density droplet discharge head using a silicon single crystal substrate capable of measuring a nozzle pattern with high accuracy. It is an object of the present invention to provide a droplet discharge head, a droplet discharge device, a method for manufacturing a droplet discharge head, and a method for manufacturing a droplet discharge device.

A droplet discharge head according to the present invention includes a nozzle hole that discharges a droplet, a discharge chamber that communicates with the nozzle hole, a liquid supply unit that supplies liquid to the discharge chamber, and a part of a wall surface of the discharge chamber. A droplet discharge head comprising a plurality of substrates stacked on each other, and the nozzle holes together with the nozzle holes on the substrate. A dummy pattern for measuring the hole diameter or the hole length is provided.
A dummy pattern dedicated to nozzle hole measurement is provided on the nozzle substrate, which makes it possible to measure the nozzle hole diameter and nozzle length of the actual nozzle hole with high accuracy. It can be obtained with good yield.

In the liquid droplet ejection head according to the present invention, the dummy pattern is provided on the inner wall side of the one substrate.
Since a dummy pattern is provided on the inner wall side of the nozzle substrate, whereby the nozzle hole diameter and the nozzle hole length can be measured with high accuracy, a droplet discharge head having stable characteristics can be obtained with a high yield.

In the droplet discharge head according to the present invention, the dummy pattern is formed in the same shape as the shape of the nozzle hole.
Since the dummy pattern has the same shape as the nozzle hole, the diameter of the nozzle hole and the nozzle hole length can be accurately measured by measuring the shape of the dummy pattern.

In the droplet discharge head according to the present invention, the hole diameter of the dummy pattern is formed larger than the hole diameter of the nozzle hole.
Even when a nozzle substrate having a small nozzle hole diameter and difficult to measure the nozzle hole diameter is created, the nozzle hole length can be accurately measured using a dummy pattern having a large diameter.

In the liquid droplet ejection head according to the present invention, a high reflectivity material is provided on the surface of the dummy pattern.
The outline of the dummy pattern is emphasized by the high reflectivity material. In addition, since it is possible to prevent charge-up that occurs when measuring the nozzle hole with an electron microscope, the nozzle hole can be measured with high accuracy.

In the liquid droplet ejection head according to the present invention, the high reflectivity material is preferably a metal.
The outline of the dummy pattern is emphasized by the metal which is a high reflectance material.

In the droplet discharge head according to the present invention, it is desirable that the high reflectivity material is any one of platinum, aluminum, nickel, chromium, gold, copper, and titanium.
The outline of the dummy pattern is emphasized by a metal such as platinum which is a high reflectivity material.

A droplet discharge apparatus according to the present invention includes any one of the droplet discharge heads described above.
A droplet discharge device having stable characteristics can be produced with a high yield.

A method for manufacturing a droplet discharge head according to the present invention includes a nozzle hole that discharges a droplet, a discharge chamber that communicates with the nozzle hole, a liquid supply unit that supplies liquid to the discharge chamber, and a wall surface of the discharge chamber. A droplet discharge head manufacturing method comprising: a diaphragm formed in a part of the substrate; and an individual electrode disposed opposite to the diaphragm, wherein a substrate is etched. And forming a single substrate by simultaneously forming a dummy pattern for measuring the hole diameter or the hole length of the nozzle hole together with the nozzle hole.
Since the dummy pattern is formed at the same time as the nozzle hole, the nozzle hole diameter or nozzle hole length can be accurately measured by the formed dummy pattern. Even if the size of the dummy pattern is changed, it can be formed while maintaining a high correlation. Therefore, even if a nozzle substrate having a small nozzle hole diameter, for which it is difficult to measure the nozzle hole length, is created, it is possible to accurately measure the nozzle hole length by creating a dummy pattern having a large diameter.

The method for manufacturing a droplet discharge head according to the present invention includes a step of measuring the diameter or length of the nozzle hole using the dummy pattern formed on the one substrate.
Since the hole diameter or hole length of the nozzle holes can be accurately measured by the dummy pattern, a droplet discharge head including a nozzle substrate having stable characteristics can be obtained with a high yield.

A method for manufacturing a droplet discharge device according to the present invention is a method for manufacturing a droplet discharge device by applying the method for manufacturing a droplet discharge head described above.
A droplet discharge head having stable characteristics can be produced with a high yield.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of an ink jet head according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view of a main part of the ink jet head assembled with FIG. In the figure, an inkjet head (droplet discharge head) 10 includes a single nozzle substrate 1 (hereinafter sometimes referred to as one nozzle substrate) in which a plurality of nozzle holes 11 are provided at predetermined intervals, and each nozzle hole. 11, the cavity substrate 2 provided with the ink supply path independently of the electrode substrate 11 and the electrode substrate 3 provided with the individual electrodes 31 facing the vibration plate 22 of the cavity substrate 2 are bonded together.

  The nozzle substrate 1 is made of a silicon base material. The nozzle hole 11 for discharging ink droplets is a nozzle hole formed in a two-stage cylindrical shape with different diameters, that is, located on the ink discharge surface 1b side, and the tip opens to the discharge concave surface 1e of the ink discharge concave portion 1c. A first nozzle hole with a small diameter (a small diameter hole at the injection port portion) 11a and a second nozzle with a large diameter that is located on the side of the bonding surface 1a to be bonded to the cavity substrate 2 and the introduction port portion opens to the bonding surface 1a The hole (large-diameter hole in the introduction port portion) 11b is provided on the discharge concave surface 1e of the ink discharge concave portion 1c, and is provided perpendicular to the substrate surface and coaxially. In this way, the ink droplet ejection direction is aligned with the central axis direction of the nozzle hole 11 to exhibit stable ink ejection characteristics, thereby eliminating variations in the flying direction of the ink droplets and eliminating the scattering of the ink droplets. Variation in the amount can be suppressed.

  Further, a dummy pattern A and a dummy pattern B dedicated for nozzle measurement are provided on the bonding surface 1a side (inner wall side) of the nozzle substrate 1 in a state where the nozzle substrate 1 is opened to the bonding surface 1a. As shown in FIG. 3, these dummy patterns A and B are arranged on the same straight line as the actual pattern nozzle hole 11 (on the line II in FIG. 3), and the dummy pattern B is the edge of the ink ejection recess 1c. The dummy pattern A is provided outside the portion 1d (on the right side of the figure from the edge 1d), and is provided between the nozzle hole 11 and the dummy pattern B in the ink discharge recess 1c. The dummy pattern A has the same diameter as the second nozzle hole 11b (large diameter hole) of the nozzle hole 11 (when the nozzle substrate 11 having a small nozzle hole diameter, which makes it difficult to measure the nozzle hole length, is created, a dummy having a large diameter is formed. The pattern can also be created), and is configured only by the second dummy hole (large diameter hole) 50b. The dummy pattern B has the same shape as the nozzle hole 11 and includes a first dummy hole (small diameter hole) 60a and a second dummy hole (large diameter hole) 60b.

The cavity substrate 2 is made of a silicon base material, and a discharge recess 210, an orifice recess 230, and a reservoir recess (liquid supply recess) 240 are formed in the cavity substrate 2. The discharge recess 210 (discharge chamber 21) and the reservoir recess 240 (reservoir 24 or liquid supply unit) communicate with each other through the orifice recess 230 (orifice 23). The reservoir 24 constitutes a common ink chamber common to the discharge chambers 21 and communicates with the discharge chambers 21 via the orifices 23. An ink supply hole 25 penetrating an electrode substrate 3 described later 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 discharge chamber 21 is a diaphragm 22. Note that an insulating SiO ₂ film 26 made of thermal oxidation or plasma CVD (Chemical Vapor Deposition) is applied to the entire surface of the cavity substrate 2 or at least the surface facing the electrode substrate 3. This insulating film 26 prevents dielectric breakdown and short circuit when the inkjet head 10 is driven.

The electrode substrate 3 is made from a glass base material. The electrode substrate 3 is provided with a recess 310 at a position facing each diaphragm 22 of the cavity substrate 2. In each recess 310, individual electrodes 31 made of ITO (Indium Tin Oxide) are formed by sputtering.
The individual electrode 31 includes a lead portion 31a and a terminal portion 31b connected to a flexible wiring board (not shown). The terminal portion 31b is exposed in the electrode extraction portion 41 in which the end portion of the cavity substrate 2 is opened for wiring. The terminal portions 31b of the individual electrodes 31 and the common electrode 27 on the cavity substrate 2 are connected via a drive control circuit 40 such as an IC driver.

  Next, the operation of the inkjet head 10 configured as described above will be described. When the drive control circuit 40 is driven and charges are supplied to the individual electrode 31 to charge it positively, the diaphragm 22 is charged negatively, and an electrostatic force is generated between the individual electrode 31 and the diaphragm 22. Due to the electrostatic force, the diaphragm 22 is attracted to the individual electrode 31 and bent. As a result, the volume of the discharge chamber 21 increases. When the supply of electric charges to the individual electrode 31 is stopped, the diaphragm 22 returns to its original state due to its elastic force, and at this time, the volume of the discharge chamber 21 decreases rapidly, and the ink in the discharge chamber 21 is reduced by the pressure at that time. A part of the ink is ejected from the nozzle hole 11 as ink droplets. Next, when the vibration plate 22 is similarly displaced, ink is supplied from the reservoir 24 through the orifice 23 into the discharge chamber 21.

  A method for manufacturing the inkjet head 10 configured as described above will be described with reference to FIGS. FIG. 3 is a top view showing the nozzle substrate 1 according to the first embodiment of the present invention, and FIGS. 4 to 5 are cross-sectional views showing the manufacturing process of the nozzle substrate 1 (cross-sectional views taken along the line II in FIG. 3). 6 to 7 are cross-sectional views showing the bonding process between the cavity substrate 2 and the electrode substrate 3. FIG. 8 shows the inkjet head 10 manufactured by bonding the nozzle substrate 1 to the bonding substrate between the cavity substrate 2 and the electrode substrate 3. It is sectional drawing which shows the manufacturing process to do.

First, the manufacturing process of the nozzle substrate 1 will be described with reference to FIGS. 4 and 5 schematically show the vicinity of the nozzle hole forming portion and the dummy pattern forming portion.
(A) First, a silicon substrate 100 having a substrate thickness of 180 μm is prepared, set in a thermal oxidation apparatus, and 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, As shown in FIG. 4A, a 1 μm thick SiO ₂ film 101 is uniformly formed on the surface of the silicon substrate 100.

(B) A resist (not shown) is coated on both surfaces of the silicon substrate 100, and the bonding surface 1a has a portion 110 that becomes the nozzle hole 11 (a portion 110b that becomes the second nozzle hole 11b) and dummy patterns A and B. Parts to be formed (the part 500b to be the second dummy hole 50b of the dummy pattern A and the part 600b to be the second dummy hole 60b of the dummy pattern B) are patterned, and a buffered hydrofluoric acid aqueous solution (hydrofluoric acid aqueous solution: ammonium fluoride) Half etching is performed with an aqueous solution = 1: 6) to thin the SiO ₂ film 2. After the resist is removed, a resist (not shown) is coated on both surfaces of the silicon substrate 100 again, and the bonding surface 1a has a portion 110 (the portion 110a that becomes the first nozzle hole 11a) and a dummy pattern. patterning the (first dummy hole 60a become part 600b of the dummy pattern B) to become part B, buffered hydrofluoric acid aqueous solution (aqueous hydrofluoric acid solution: an aqueous solution of ammonium fluoride = 1: 6) is etched by, SiO ₂ film 101 To open. When the opening of the SiO ₂ film 101 is finished, the resist on both sides is peeled off. In this way, as shown in FIG. 4B, half etching and opening of the SiO ₂ film 101 are performed.

(C) An opening of the SiO ₂ film 101 is vertically anisotropically etched at a depth of 25 μm by an ICP dry etching apparatus, so that the first nozzle hole 11a of the nozzle hole 11 and the first dummy of the dummy pattern B Hole 60a is formed. As an etching gas in this case, for example, C ₄ F ₈ and SF ₆ are used, and these etching gases may be used alternately. Here, C ₄ F ₈ is used to protect the groove side surface so that the etching does not proceed to the side surface of the groove to be formed, and SF ₆ is used to promote the etching of the silicon substrate 100 in the vertical direction. .
Next, only the SiO ₂ film 101 of the portion 110b that becomes the second nozzle hole 11b, the portion 500b that becomes the second dummy hole 50b of the dummy pattern A, and the portion 600b that becomes the second dummy hole 60b of the dummy pattern B Half-etching is performed using a buffered hydrofluoric acid solution so as to disappear, and anisotropic dry etching of the opening of the SiO ₂ film 101 is performed vertically at a depth of 40 μm using an ICP dry etching apparatus again. Thus, as shown in FIG. 4C, the nozzle holes 11 and the dummy patterns A and B are formed.

(D) The SiO ₂ film 101 remaining on the surface of the silicon substrate 100 is removed with an aqueous hydrofluoric acid solution. Thereafter, the silicon substrate 100 is set in a thermal oxidation apparatus, and a thermal oxidation process is performed under conditions in an oxidation temperature of 1075 ° C., an oxidation time of 4 hours, and a mixed atmosphere of water vapor and oxygen, as shown in FIG. Ink ejection surface 1b, bonding surface 1a of silicon substrate 100, nozzle hole 11 (first nozzle hole 11a and second nozzle hole 11b) processed by ICP dry etching apparatus, dummy pattern A (second dummy hole 50b) ) And the dummy pattern B (the first dummy hole 60a and the second dummy hole 60b), the 1 μm thick SiO ₂ film 102 is uniformly formed on the side surface and the bottom surface.
(E) Resist (not shown) is coated on both surfaces 1a and 1b of the silicon substrate 100, and the portion 100c to be the ink discharge recess 1c is patterned, and a buffered hydrofluoric acid aqueous solution (hydrofluoric acid aqueous solution: ammonium fluoride aqueous solution = 1). : Etching in 6), as shown in FIG. 5E, the SiO ₂ film 102 is opened, and the resist is peeled off.

(F) The silicon substrate 100 is immersed in a 25 wt% potassium hydroxide aqueous solution, and the portion 100c that becomes the ink discharge recess 1c is etched to form the ink discharge recess 1c as shown in FIG. 5 (f). . At this time, the thickness of the silicon substrate 100 in the etched portion is set to 60 μm.
(G) The SiO ₂ film 102 on the surface of the silicon substrate 100 is removed with a hydrofluoric acid aqueous solution or the like, and the nozzle substrate 1 as shown in FIG. 5G is completed.
By doing so, the dummy pattern B (first dummy hole 60a) formed simultaneously with the nozzle hole 11 (first nozzle hole 11a) and the dummy pattern formed simultaneously with the nozzle hole 11 (second nozzle hole 11b). A nozzle substrate 1 including A (second dummy hole 50b) and dummy pattern B (second dummy hole 60b) is formed.

(H) After the nozzle hole 11 and the dummy patterns A and B are formed and the nozzle substrate 1 is completed, the accuracy of the nozzle pattern of the nozzle hole 11 formed in the nozzle substrate 1 is increased using the dummy patterns A and B. Measure with an electron microscope (not shown).
In the measurement, the depth and the hole diameter of the nozzle holes 11 (first nozzle hole 11a, second nozzle hole 11b) are the same as the dummy pattern B (first dummy hole 60a, second dummy hole). Measurement can be performed using the hole 60b) and the dummy pattern A (second dummy hole 50b).

Since these dummy patterns A and B are formed at the same time as the nozzle holes 11, even if the size is changed, the patterns can be formed while maintaining a high correlation. Therefore, even if the nozzle substrate 1 having a small nozzle hole diameter, for which it is difficult to measure the nozzle hole length, is created, it is possible to accurately measure the nozzle hole length by creating a dummy pattern having a large diameter.
Thus, by measuring the nozzle hole 11 using the dummy patterns A and B, it is possible to measure the depth and the hole diameter of the minute nozzle hole 11 with high accuracy in a non-destructive manner.
By passing through the above process, the nozzle substrate 1 provided with the highly accurate nozzle hole 11 can be obtained from the silicon substrate 100.

Next, the bonding process of the cavity substrate 2 and the electrode substrate 3 will be described with reference to FIGS. Note that the bonding process of the cavity substrate 2 and the electrode substrate 3 is not limited to the one shown in FIGS.
(A) First, as shown in FIG. 6 (a), a glass substrate 300 made of borosilicate glass or the like is etched with hydrofluoric acid using, for example, a gold / chromium etching mask, thereby forming a recess 310. Form. The recess 310 has a groove shape slightly larger than the shape of the electrode 31, and a plurality of the recesses 310 are formed.
Then, an electrode 31 made of ITO (Indium Tin Oxide) is formed inside the recess 310 by sputtering. Thereafter, a hole 25a to be the ink supply hole 25 is formed by a drill or the like.

(B) Next, after both surfaces of the silicon substrate 200 are mirror-polished, as shown in FIG. 6 (b), silicon made of TEOS (TetraEthylOrthosilicate) is formed on one surface of the silicon substrate 200 by plasma CVD (Chemical Vapor Deposition). An oxide film 201 is formed. Note that a boron doped layer for etching stop may be formed before the silicon oxide film 201 is formed. By forming the diaphragm 22 from a boron-doped layer, the diaphragm 22 with high thickness accuracy can be formed.
(C) Then, as shown in FIG. 6 (c), the silicon substrate 200 shown in FIG. 6 (b) and the glass substrate 300 shown in FIG. 6 (a) are heated to, for example, 360 ° C. An anode is connected to 200 and a cathode is connected to the glass substrate 300, and a voltage of about 800 V is applied to perform anodic bonding.
(D) After anodic bonding of the silicon substrate 200 and the glass substrate 300, the bonded substrate obtained in the step of FIG. 6 (c) is etched with an aqueous potassium hydroxide solution or the like, so that it is shown in FIG. 6 (d). Thus, the entire silicon substrate 200 is thinned.

(E) Then, a TEOS film is formed on the entire upper surface of the silicon substrate 200 (the surface opposite to the surface to which the glass substrate 300 is bonded) by plasma CVD.
Then, a resist for forming a recess 210 serving as the discharge chamber 21, a recess 240 serving as the reservoir 24, and a recess 230 serving as the orifice 23 is patterned on the TEOS film, and the TEOS film in this portion is removed by etching.
Thereafter, as shown in FIG. 7E, the silicon substrate 200 is etched with a potassium hydroxide aqueous solution or the like, thereby forming a recess 210 serving as the discharge chamber 21, a recess 240 serving as the reservoir 24, and a recess 230 serving as the orifice 23. Form. At this time, the portion 41a to be the electrode extraction portion 41 is also etched to be thinned. In the wet etching step shown in FIG. 7E, for example, a 35% by weight potassium hydroxide aqueous solution can be used first, and then a 3% by weight potassium hydroxide aqueous solution can be used. Thereby, surface roughness of the diaphragm 22 can be suppressed.

(F) After the etching of the silicon substrate 200 is completed, the bonding substrate is etched with a hydrofluoric acid aqueous solution to remove the TEOS film formed on the silicon substrate 200. Then, as shown in FIG. 7 (f), laser processing is performed on the hole 25 a that becomes the ink supply hole 25 of the glass substrate 300 so that the ink supply hole 25 penetrates the glass substrate 300. Thus, the electrode substrate 3 is manufactured.
(G) Next, as shown in FIG. 7G, a droplet protective film 202 made of TEOS or the like is formed on the surface of the silicon substrate 200 where the recesses 21a to be the discharge chambers 21 are formed, as shown in FIG. To do.
(H) Then, as shown in FIG. 7 (h), the electrode extraction portion 41 is opened by RIE (Reactive Ion Etching) or the like. Further, the silicon substrate 200 is machined or laser processed to penetrate the ink supply hole 25 to the concave portion 240 that becomes the reservoir 24. As a result, a bonded substrate in which the cavity substrate 2 and the electrode substrate 3 are bonded is completed.
A sealing agent (not shown) for sealing the space between the diaphragm 22 and the electrode 31 may be applied to the electrode extraction portion 41.

Next, the bonding process of the nozzle substrate 1, the cavity substrate 2 and the electrode substrate 3 will be described below with reference to FIG.
As shown in FIG. 8, an adhesive layer is formed on the bonding surface 1 a of the nozzle substrate 1, and the cavity substrate 2 to which the electrode substrate 3 is bonded is bonded to the nozzle substrate 1.
By passing through the above manufacturing process, the joined body of the nozzle substrate 1, the cavity substrate 2 and the electrode substrate 3 is completed.
Finally, the bonded substrate to which the nozzle substrate 1, the cavity substrate 2, and the electrode substrate 3 are bonded is separated by dicing (cutting), and the inkjet head 10 is completed.

  In the present invention, as shown in the first embodiment, the dummy patterns A and B dedicated to nozzle measurement are formed at the same time as the nozzle holes 11 which are actual patterns on one nozzle substrate 1, so that the nozzle pattern is measured with high accuracy. can do. Thus, since the nozzle hole diameter and nozzle hole length of the nozzle hole 11 can be measured with high accuracy, the inkjet head 10 having stable characteristics can be manufactured with high yield.

Embodiment 2. FIG.
FIG. 9 is a cross-sectional view showing the nozzle substrate 1 of the inkjet head 10 according to Embodiment 2 of the present invention. In the first embodiment, the dummy patterns A and B dedicated to nozzle measurement are formed on the nozzle substrate 1, but in the second embodiment, a high reflectivity material is provided on the surfaces of the dummy patterns A and B.
That is, in the first embodiment, the dummy patterns A and B are provided on the bonding surface 1a side of the nozzle substrate 1 (FIGS. 2 and 5G). In the second embodiment, the dummy patterns A and B are shown in FIG. As described above, the high-reflectance material 70 is formed on the surfaces of the dummy patterns A and B to emphasize the outline, and when the pattern of the nozzle holes 11 is measured using the dummy patterns A and B, The pattern can be measured with higher accuracy.
In this case, in order to emphasize the outline of the dummy patterns A and B, a metal high reflectivity material 70 such as platinum (Pt), aluminum (Al), nickel (Ni), chromium (Cr), gold (Au) or the like is used. The selective sputtering is performed only on the dummy patterns A and B.

The manufacturing process of the nozzle substrate 1 according to the second embodiment is the manufacturing process shown in FIG. 9 after the manufacturing processes (a) to (g) of the nozzle substrate 1 shown in the first embodiment. In this case, a metal film is selectively formed on only the dummy patterns A and B by sputtering to form the high reflectivity material 70.
By doing so, it is possible to prevent charge-up that occurs when measuring the nozzle hole diameter with an electron microscope, and therefore it is possible to measure the nozzle hole diameter with high accuracy.
According to the second embodiment, since the nozzle hole diameter and the nozzle hole length can be measured with high accuracy, the inkjet head 10 including the nozzle substrate 1 having stable characteristics can be produced with a high yield. .

Embodiment 3. FIG.
FIG. 10 is a perspective view of an ink jet printer according to Embodiment 3 of the present invention. According to the present invention, it is possible to produce an inkjet head 10 having stable characteristics with a high yield, and an inkjet printer 500 that requires high nozzle hole diameter accuracy as shown in FIG. 10 using the inkjet head 10. Can be obtained.
The inkjet head 10 obtained by the manufacturing method of Embodiments 1 and 2 is an example of a droplet discharge head. By changing the droplets in various ways, a liquid crystal display color filter can be manufactured, and an organic EL display device can be manufactured. The present invention can also be applied to micro-droplet discharge devices such as the formation of a light emitting portion and the discharge of a biological liquid.

1. The depth of the dummy pattern A formed with a large hole diameter was measured using an image measuring machine and compared with the true value.
The depth of the second nozzle hole 11b is an important measurement value for calculating the nozzle length of the first nozzle hole 11a that cannot be directly measured, but when the second nozzle hole 11b becomes smaller, the depth is focused on the bottom surface. It becomes very difficult to measure together. Therefore, the depth of the dummy pattern A was measured using a Mitutoyo three-dimensional image measuring machine QVT404-PRO. Moreover, the true value of the depth of the second nozzle hole 11b was measured using an electron microscope S-4700 manufactured by Hitachi. In Example 1, the dummy pattern A had a diameter of 29.56 μm, and the second nozzle hole 11b had a diameter of 20.8 μm.
The results of each depth measurement are shown in Table 1 (unit: μm).

  By measuring using the dummy pattern A in this way, it becomes possible to measure the depth of the minute nozzle hole 11 in a non-destructive manner with high accuracy.

2. The hole diameter of the dummy pattern B was measured with a length measurement SEM, and the result compared with the true value was as follows.
The hole diameter of the first nozzle hole 11a and the hole diameter of the first dummy hole 60a of the dummy pattern B were measured using a length measuring electron microscope S-6100 manufactured by Hitachi, Ltd. Further, in order to measure the true value, the first nozzle hole 11a was measured by depositing Au by sputtering with 20 nm.
The results of each depth measurement are shown in Table 2 (unit: μm).

  By measuring using the dummy pattern B in this way, it is possible to measure the diameter of the minute nozzle hole 11 with nondestructive accuracy.

1 is an exploded perspective view of a droplet discharge head according to a first embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a main part of a droplet discharge head assembled from FIG. 1. The top view of the principal part of the nozzle substrate of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate following FIG. Sectional drawing which shows the manufacturing process of the joining board | substrate which joined the cavity board | substrate and the electrode substrate. Sectional drawing which shows the manufacturing process of the bonded substrate following FIG. Sectional drawing which shows the manufacturing process which joins the bonding substrate of a cavity substrate and an electrode substrate to a nozzle substrate. Sectional drawing which shows 1 process of nozzle board | substrate manufacture which concerns on Embodiment 2 of this invention. FIG. 6 is a perspective view of an ink jet printer according to a third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle board | substrate (one board | substrate), 1a Joining surface (inner wall) of nozzle board | substrate, 1c Ink discharge recessed part, 1e Discharge concave surface, 2 Cavity board | substrate, 3 Electrode board | substrate, 10 Inkjet head (droplet discharge head), 11 Nozzle hole, 11a 1st nozzle hole (small diameter hole), 11b 2nd nozzle hole (large diameter hole), 21 discharge chamber, 22 diaphragm, 24 reservoir (liquid supply part), 31 individual electrode, 50b 2nd dummy hole ( Large diameter hole), 60a first dummy hole (small diameter hole), 60b second dummy hole (large diameter hole), 70 high reflectivity material, 100 silicon substrate, 500 inkjet printer (droplet ejection device), A , B Dummy pattern.

Claims (11)

A nozzle hole for discharging liquid droplets, a discharge chamber communicating with the nozzle hole, a liquid supply unit for supplying liquid to the discharge chamber, a diaphragm formed on a part of the wall surface of the discharge chamber, and the vibration A droplet discharge head comprising a plate and an individual electrode arranged opposite to each other, wherein a plurality of substrates are laminated,
A droplet discharge head, wherein a dummy pattern for measuring a hole diameter or a hole length of the nozzle hole is provided on one substrate together with the nozzle hole.   The droplet discharge head according to claim 1, wherein the dummy pattern is provided on an inner wall side of the one substrate.   3. The liquid droplet ejection head according to claim 1, wherein the dummy pattern is formed in the same shape as the shape of the nozzle hole.   The droplet discharge head according to claim 1, wherein a hole diameter of the dummy pattern is formed larger than a hole diameter of the nozzle hole.   The liquid droplet ejection head according to claim 1, wherein a high reflectivity material is provided on a surface of the dummy pattern.   6. The droplet discharge head according to claim 5, wherein the high reflectivity material is a metal.   7. The droplet discharge head according to claim 6, wherein the high reflectivity material is any one of platinum, aluminum, nickel, chromium, gold, copper, and titanium.   A droplet discharge apparatus comprising the droplet discharge head according to claim 1. A nozzle hole for discharging liquid droplets, a discharge chamber communicating with the nozzle hole, a liquid supply unit for supplying liquid to the discharge chamber, a diaphragm formed on a part of the wall surface of the discharge chamber, and the vibration A method for manufacturing a droplet discharge head, comprising a plate and an individual electrode disposed opposite to each other, and a plurality of substrates laminated.
A droplet discharge head comprising: a step of etching a base material and simultaneously forming a dummy pattern for measuring a hole diameter or a hole length of the nozzle hole together with the nozzle hole to form a substrate. Manufacturing method.   The method of manufacturing a droplet discharge head according to claim 9, further comprising a step of measuring a hole diameter or a hole length of the nozzle hole using the dummy pattern formed on the one substrate. A method for manufacturing a droplet discharge device, wherein the method for manufacturing a droplet discharge head according to claim 9 or 10 is applied to manufacture a droplet discharge device.

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