JP2008207493A - Droplet discharge head, method for manufacturing droplet discharge head, and droplet discharge apparatus - Google Patents

Abstract

Disclosed is a droplet discharge head, a method for manufacturing the droplet discharge head, and a liquid capable of reducing the manufacturing cost while enabling a high density of nozzles and ensuring a sufficient reservoir volume for preventing crosstalk. A droplet discharge device is provided.
SOLUTION: A plurality of cavity holes 12a, a plurality of cavity recesses 12a that are communicated with each of the nozzle holes, generate pressure inside, and serve as cavities 12 for discharging droplets from the nozzle holes, and cavity recesses 12a And a reservoir recess 13a that serves as a reservoir 13 for storing droplets to be supplied to the cavity recess 12a, and a plurality of orifices that communicate the cavities 12 with the reservoir 13. The substrate 1, the diaphragm substrate 2 having the diaphragm 21 joined to the channel substrate 1 and generating pressure in the cavity 12 of the channel substrate 1, and the diaphragm 21 is deformed to change the pressure in the cavity 12. Providing actuator.
[Selection] Figure 1

Description

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

  As a droplet discharge head for discharging droplets, for example, an inkjet head mounted on an inkjet recording apparatus is known. In general, an inkjet head includes a nozzle substrate in which a plurality of nozzle holes for discharging ink droplets are formed, and a pressure chamber (cavity) that is joined to the nozzle substrate and communicates with the nozzle holes. And a flow path substrate on which ink flow paths such as a reservoir are formed, and a diaphragm formed on the bottom surface of the cavity is displaced by a driving means, and pressure is applied to the cavity so that ink droplets are selected from the selected nozzle holes. It is comprised so that it may discharge. As the driving means, there are a method using an electrostatic force, a piezoelectric method using a piezoelectric element, a method using a heating element, and the like.

In recent years, inkjet heads have increased in number of nozzles in order to cope with high-speed printing, and minute drive mechanisms (actuators) have been demanded from the demand for higher resolution. When the drive mechanism is miniaturized and densified, the partition wall of the cavity provided for each nozzle that ejects ink becomes thinner and the rigidity of the partition wall becomes lower. Therefore, when ink in one cavity is ejected There was a so-called crosstalk problem that adjacent cavities were affected. Such a crosstalk problem also occurs when the cavity pressure is applied to other cavities via the reservoir. In order to prevent such crosstalk, the conventional ink-jet head has responded by providing the reservoir separately from the flow path substrate on which the cavity is formed, and ensuring a large reservoir volume ( For example, see Patent Document 1).
Japanese Patent Laying-Open No. 2006-103167 (FIG. 1)

  However, although the conventional ink jet head has an advantage that the reservoir volume can be secured by providing the reservoir substrate, there is a problem in that the number of parts is increased, resulting in an increase in member cost and assembly cost.

  The present invention has been made in view of these points, and enables droplet discharge that enables a high density of nozzles and a sufficient reservoir volume to prevent crosstalk while reducing manufacturing costs. It is an object to obtain a head, a method for manufacturing a droplet discharge head, and a droplet discharge device.

A droplet discharge head according to the present invention includes a plurality of nozzle holes, a plurality of cavity recesses that communicate with each of the nozzle holes, generate pressure inside, and serve as cavities for discharging droplets from each nozzle hole, A flow path substrate formed on the same side as the cavity recess and serving as a reservoir for storing droplets to be supplied to the cavity recess, and a plurality of orifices communicating each cavity and the reservoir; A vibration plate substrate having a vibration plate that is bonded to the flow path substrate and generates pressure in the cavity of the flow path substrate, and an actuator that deforms the vibration plate and changes the pressure in the cavity are provided.
As described above, since the nozzle hole, the cavity, and the reservoir are formed on one flow path substrate, the member cost and the assembly cost can be reduced.
In addition, since the cavity and the diaphragm are formed of separate substrates, the cavity is not limited by the cavity depth and the diaphragm thickness, unlike the conventional structure in which the bottom surface of the cavity is a diaphragm. The thickness of the substrate on which the film is formed, that is, the flow path substrate can be freely selected. For this reason, by selecting a substrate having a sufficient thickness as the flow path substrate, it is possible to ensure a sufficient reservoir volume for preventing crosstalk while ensuring an optimum cavity depth for ejection. As a result, it is possible to increase the density of the nozzles, and it is possible to obtain an ink jet head having good ejection characteristics by preventing pressure interference between the nozzles that occurs during ink ejection.

The liquid droplet ejection head according to the present invention is a piezoelectric device in which a voltage is applied to a piezoelectric element formed on the surface of the diaphragm opposite to the flow path substrate, and the diaphragm is deformed by deformation of the piezoelectric element. It is an actuator.
Thereby, an ink jet head having both high-precision ink droplet control and high-output ejection energy can be obtained.

Further, the droplet discharge head according to the present invention generates an electrostatic force by applying a voltage between the vibration plate and the electrode spaced apart from the vibration plate by a certain distance, and vibrates using the electrostatic force. This is an electrostatic actuator that deforms a plate.
Thereby, an inexpensive ink jet head having a high density and a large number of nozzles can be obtained.

Further, the droplet discharge head according to the present invention is such that the nozzle hole is gradually or gradually decreased from the joint surface of the flow path substrate with the diaphragm substrate toward the opposite surface. is there.
Thereby, it becomes possible to suppress an increase in flow path resistance due to an increase in the nozzle length. Further, since the nozzle diameter becomes smaller in the ejection direction, there is also an effect of improving the straightness in the ink ejection direction by the rectifying action.

In the droplet discharge head according to the present invention, the depth of the concave portion for the reservoir is deeper than the depth of the concave portion for the cavity.
As a result, a sufficient volume of the reservoir can be secured, and pressure fluctuations due to driving can be efficiently absorbed.

In the droplet discharge head according to the present invention, the depth of the orifice is the same as the depth of the cavity recess, and the width of the orifice is smaller than the width of the cavity recess.
Thereby, the orifice can be processed simultaneously in the process of forming the cavity, and the number of processes can be reduced.

A method for manufacturing a droplet discharge head according to the present invention is a method for manufacturing a droplet discharge head according to any one of the above, wherein a nozzle hole, a cavity, a reservoir, and an orifice are formed on a flow path substrate base material. In this method, the flow path substrate base material is formed by dry etching from one side using a single mask member in which all corresponding opening patterns are formed.
Thereby, the alignment accuracy and shape accuracy of each part (nozzle hole, cavity, orifice and reservoir) can be improved.

A method for manufacturing a droplet discharge head according to the present invention is the method for manufacturing a droplet discharge head according to any one of the above, wherein the nozzle hole, the cavity, a part of the reservoir, and the orifice are connected to the channel substrate base. When forming on the material, it is formed by dry etching the flow path substrate substrate from one side using one mask member in which all of the corresponding opening patterns are formed, and then the same as above The remaining portion of the reservoir is formed by wet etching using a mask member different from the mask member from one surface side.
As described above, when forming a reservoir with a large etching amount, dry etching and wet etching are used in combination, so that the reservoir can be formed with high throughput.

In the method for manufacturing a droplet discharge head according to the present invention, the mask member used when etching the flow path substrate base material is a thermal oxide film.
Thus, since the thermal oxide film is used as the mask member, a dense and uniform mask can be formed with good throughput.

In the method of manufacturing a droplet discharge head according to the present invention, the mask member used when the remaining portion of the reservoir is formed on the flow path substrate base material by wet etching has an opening formed in a portion corresponding to the reservoir. Yes, when forming the opening, a thermal oxide film is formed on the entire surface of the flow path substrate substrate on which the nozzle hole, cavity, part of the reservoir and orifice are formed, and then the mask corresponding to the reservoir is opened. The substrate is formed by bringing the substrate into close contact with the reservoir forming surface side of the flow path substrate base material and dry etching the thermal oxide film.
As a result, of the thermal oxide film formed on the entire substrate substrate, only the portion corresponding to the reservoir is accurately removed from the thermal oxide film on the bottom surface of the concave portion where the reservoir is formed halfway. Is possible.

The method for manufacturing a droplet discharge head according to the present invention uses RIE for dry etching of a thermal oxide film.
Due to the good straightness of RIE, the thermal oxide film on the bottom surface of the recess having a certain distance from the mask substrate can be accurately opened.

A droplet discharge apparatus according to the present invention is equipped with any of the above-described droplet discharge heads.
Accordingly, it is possible to obtain a droplet discharge device including a droplet discharge head having good discharge characteristics by preventing pressure interference between nozzles that occurs during droplet discharge.

  Hereinafter, embodiments of a droplet discharge head to which the present invention is applied will be described. Here, as an example of a droplet discharge head, a face discharge type inkjet head that discharges ink droplets from nozzle holes provided on the surface of a nozzle substrate will be described. Note that the present invention is not limited to the structure and shape shown in the following drawings, and is similarly applied to an edge discharge type droplet discharge head that discharges ink droplets from nozzle holes provided at the end of the substrate. Can be applied.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a schematic configuration of an ink jet head according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view showing an assembled state of the ink jet head shown in FIG. 1 and 2 show an inkjet head in which the actuator (driving means) is a piezoelectric drive system, but it is not limited to the piezoelectric drive system, and other drive systems such as an electrostatic drive system may be used. .

  In FIG. 1 and FIG. 2, an ink jet head (an example of a droplet discharge head) 10 includes a flow path substrate 1 and a diaphragm substrate 2. Hereinafter, the configuration of each substrate will be described in detail.

  The flow path substrate 1 is composed of, for example, a single crystal silicon substrate having a thickness of 300 μm and a plane orientation (100). A plurality of nozzle holes 11 are vertically formed in the flow path substrate 1 at a predetermined pitch. The nozzle row 11 may be a plurality of rows. Each nozzle hole 11 is formed so as to decrease stepwise or gradually from the joint surface with the diaphragm substrate 2 toward the opposite surface. In this example, the first nozzle hole 11a, the second nozzle hole 11b, and the third nozzle hole 11c are formed in a three-stage configuration in order from a hole having a small diameter. By comprising in this way, there exists an effect which suppresses the increase in flow-path resistance by nozzle length becoming long. In addition, since the nozzle diameter decreases toward the ejection port, there is also an effect of improving the straightness in the ink ejection direction by the rectifying action.

  Further, in the flow path substrate 1, the joint surface with the diaphragm substrate 2 communicates independently with each nozzle hole 11, and becomes a cavity 12 that generates pressure inside and discharges ink from each nozzle hole 11. A cavity recess 12 a, a reservoir recess 13 a serving as a reservoir 13 for storing ink to be supplied to each cavity 12, and a plurality of orifices 14 communicating each cavity 12 and the reservoir 13 are formed. In addition, the width of the orifice 14 is formed smaller than the width of the cavity recess 12a in order to adjust the channel resistance.

  The diaphragm substrate 2 is made of stainless steel having a thickness of 30 μm, for example. A portion of the diaphragm substrate 2 that faces the cavity 12 is a diaphragm 21, and a piezoelectric element 22 is formed on the surface of the diaphragm 21 opposite to the cavity 12. The piezoelectric element 22 has a configuration in which an upper electrode film 24 and a lower electrode film 25 are formed on both surfaces of a piezoelectric film (PZT) 23 made of, for example, a piezoelectric element. In this embodiment, the lower electrode film 25 is used as a common electrode for the piezoelectric element 22 and the upper electrode film 24 is used as an individual electrode for the piezoelectric element 22. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. Here, the piezoelectric element 22 and the vibration plate 21 that is displaced by driving the piezoelectric element 22 are collectively referred to as a piezoelectric actuator.

  The diaphragm substrate 2 is formed with an ink supply hole 26 for supplying ink in an external ink cartridge (not shown) to the reservoir 13 of the flow path substrate 1.

Here, the operation of the inkjet head 10 configured as described above will be described.
Ink jet head 10 is supplied with ink in an external ink cartridge (not shown) into reservoir 13 through ink supply holes 26, and ink is further passed from individual orifices 14 through respective cavities 12 to nozzle holes 11. Filled up to the tip. A drive control circuit (not shown) such as a driver IC for controlling the operation of the inkjet head 10 includes an upper electrode film 24 serving as each individual electrode of the piezoelectric element 22 and a lower electrode film 25 serving as a common electrode. Connected between.

  Therefore, when a drive signal (pulse voltage) is applied to the piezoelectric element 22 by this drive control circuit, the lower electrode film 25, the piezoelectric film, and the diaphragm 21 are deformed and the pressure in the cavity 12 is increased. Ink droplets are ejected.

  According to the inkjet head 10 according to the first embodiment, since the nozzle hole 11, the cavity 12, and the reservoir 13 are formed in one flow path substrate 1, the member cost and the assembly cost can be reduced. It becomes possible.

  Further, since the cavity 12 and the diaphragm 21 are formed of different substrates, the depth of the cavity 12 and the thickness dimension of the diaphragm 21 are limited as in the conventional structure in which the bottom surface of the cavity 12 is the diaphragm 21. The thickness of the substrate on which the cavity 12 is formed, that is, the flow path substrate 1 can be freely selected. For this reason, by selecting a substrate having a sufficient thickness as the flow path substrate 1, it is possible to ensure a sufficient reservoir volume for preventing crosstalk while ensuring an optimum depth of the cavity 12 for ejection. . As a result, it is possible to increase the density of the nozzles, and it is possible to obtain an ink jet head having good ejection characteristics by preventing pressure interference between the nozzles that occurs during ink ejection.

  In order to secure a sufficient reservoir volume, the first embodiment has a head structure in which the cavity 12 and the diaphragm 21 are formed of different substrates as described above, and the depth of the reservoir recess 13a. Is formed deeper than the depth of the cavity recess 12a, it is possible to efficiently absorb pressure fluctuations caused by driving.

  Further, since the ink jet head 10 of the first embodiment employs a piezoelectric drive type, an ink jet head having both high-precision ink droplet control and high-output ejection energy can be obtained.

  Further, since the nozzle hole 11 is formed so as to decrease stepwise or gradually toward the tip in the ejection direction, and the ink inlet diameter with respect to the nozzle hole 11 is formed larger than the outlet diameter, the nozzle length becomes longer. Accordingly, it is possible to suppress an increase in flow path resistance. Further, since the nozzle diameter becomes smaller in the ejection direction, there is also an effect of improving the straightness in the ink ejection direction by the rectifying action.

  Next, a method for manufacturing the inkjet head 10 according to the first embodiment will be described with reference to FIGS. Note that the values of the substrate thickness, etching depth, temperature, pressure and the like shown below are merely examples, and the present invention is not limited to these values. Here, a manufacturing method of the flow path substrate 1 will be described, and a conventionally known method can be used as a manufacturing method of the diaphragm substrate 2 having the piezoelectric elements 22, and thus description thereof is omitted here.

(A) A flow path substrate 100 made of a single crystal silicon substrate having a thickness of 300 μm and a plane orientation (100) is prepared, and a thermal oxide film having a thickness of 2.8 μm is formed on the outer surface of the flow path substrate 100. 101 is formed. The first nozzle hole 11a, the second nozzle hole 11b, the third nozzle hole 11c, the cavity 12, the orifice 14, and the reservoir 13 are formed on the thermal oxide film 101 on the surface A to be bonded to the diaphragm substrate 2. The portions 111a, 111b, 111c, 112, 114, and 113 are opened by a photolithography method. At this time, etching is performed so that the remaining film thickness of the thermal oxide film 101 in each of the portions 111a, 111b, 111c, 112, 114, and 113 on the A plane has the following relationship.
The portion 111a to be the first nozzle hole 11a = 0 <the portion 111b to be the second nozzle hole 11b <the portion 111c to be the third nozzle hole 11c = the portion 113 to be the reservoir 13 <the portion 113 to be the cavity 12 112 = the orifice 14 Part 114

(B) Next, the portion 111a which becomes the first nozzle hole 11a on the A surface is dry-etched by ICP to about 100 μm.
(C) Next, an appropriate amount of the thermal oxide film 101 is removed by etching to open the portion 111b that becomes the second nozzle hole 11b, and the portion 111b that becomes the second nozzle hole 11b is etched by about 50 μm by dry etching using ICP. To do.

(D) Next, an appropriate amount of the thermal oxide film 101 is removed by etching to open the portion 111c that becomes the third nozzle hole 11c and the portion 113 that becomes the reservoir 13, and the third nozzle hole 11c is formed by dry etching using ICP. The portion 111 c to be formed and the portion 113 to be the reservoir 13 are etched by about 170 μm.
(E) Then, the thermal oxide film 101 is removed by an appropriate amount to open the portion 112 that becomes the cavity 12 and the portion 114 that becomes the orifice 14, and the portion 112 and orifice 14 that become the cavity 12 by dry etching using ICP. The portion 114 to be formed is etched by about 80 μm. At this time, the portion 113 which becomes the reservoir 13 is similarly etched, and the cavity recess 12a, the orifice 14 and the reservoir recess 13a are formed at desired depths, respectively. Also, the portion 111a that becomes the first nozzle hole 11a, the portion 111b that becomes the second nozzle hole 11b, and the portion 111c that becomes the third nozzle hole 11c are similarly dry-etched and penetrate the flow path substrate base material 100 to form nozzle holes. 11 is formed.
(F) Then, after removing the thermal oxide film 101, a thermal oxide film 120 having a thickness of 0.1 μm is formed again as an ink protective film.
Thus, the flow path substrate 1 is manufactured.

  The ink jet head 10 is manufactured by adhering the diaphragm substrate 2 formed with the piezoelectric elements 22 and the ink supply holes 26 to the flow path substrate 1 manufactured in this way with an adhesive.

  As described above, in the method of manufacturing the inkjet head 10 according to the first embodiment, the nozzle hole 11, the cavity 12, the orifice 14, and the reservoir 13 are provided on the joint surface side with the diaphragm substrate 2, and all of the flow path substrate 1 is provided. This process can be completed by single-sided processing from the joint surface side, so that yield and productivity can be improved.

  Further, when forming each part (nozzle hole 11, cavity 12, orifice 14 and reservoir 13) in the flow path substrate base material 100, each part (nozzle hole 11, cavity 12, orifice 14 and reservoir 13) is formed. Since it is formed by single-sided dry etching using one mask member (thermal oxide film 101) in which all the opening patterns corresponding to each are formed, each time each part is formed, a mask corresponding to that part is formed. Compared with the method of re-forming the member, the alignment accuracy and shape accuracy of each part can be improved.

  Further, since all the parts of the flow path substrate 1 are formed by dry etching, each part can be formed with high accuracy.

  Further, since the thermal oxide film 101 is used as a mask member used when forming each part on the flow path substrate base material 100, a dense and uniform mask can be formed with good throughput.

Embodiment 2. FIG.
5 is an exploded perspective view showing a schematic configuration of the inkjet head according to Embodiment 2 of the present invention, and FIG. 6 is a longitudinal sectional view showing an assembled state of the inkjet head shown in FIG. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and description is abbreviate | omitted.
In the inkjet head 200 according to the second embodiment, the actuator (driving means) is an electrostatic drive system, and the reservoir 13 portion of the flow path substrate 1 is manufactured only by dry etching in the first embodiment. Instead of this, in the second embodiment, both dry etching and wet etching are used.

The inkjet head 200 according to the second embodiment is of the electrostatic drive type as described above, and the piezoelectric element 22 provided on the diaphragm substrate 2 in the first embodiment is omitted. Further, at least the surface of the diaphragm substrate 2 on the electrode substrate 3 side is made of SiO ₂ by plasma CVD (Chemical Vapor Deposition) using, for example, TEOS (Tetraethylorthosilicate Tetraethoxysilane) as a raw material. An insulating film made of a film is formed with a thickness of 0.1 μm, for example (not shown). This insulating film is provided in order to prevent dielectric breakdown or short circuit when the inkjet head 10 is driven.

An electrode substrate 3 is bonded to the surface of the diaphragm substrate 2 opposite to the flow path substrate 1. The electrode substrate 3 is made of, for example, a glass material having a thickness of about 1 mm. The electrode substrate 3 is provided with electrode recesses 31 at positions on the surface of the diaphragm substrate 2 facing the diaphragms 21. Each electrode recess 31 is formed to a depth of about 0.3 μm by etching. In general, individual electrodes 32 made of ITO (Indium Tin Oxide) are formed on the bottom surface of each electrode recess 31 to a thickness of, for example, 0.1 μm by sputtering. Therefore, the gap G (gap) formed between the diaphragm 21 and the individual electrode 32 is determined by the depth of the electrode recess 31 and the thickness of the insulating film covering the individual electrode 32 and the diaphragm 21. Become. This gap G greatly affects the ejection characteristics of the inkjet head 200. In the case of the second embodiment, the gap G is 0.2 μm. The open end of the gap G is hermetically sealed with a sealing material 33 made of an epoxy adhesive or the like. Thereby, it is possible to prevent foreign matter, moisture, and the like from entering the gap G, and the reliability of the ink jet head 200 can be kept high.
The material of the individual electrode 32 is not limited to ITO, and metal such as IZO (Indium Zinc Oxide) or gold or copper may be used. However, since ITO is transparent, ITO is generally used because it is easy to check the contact state of the diaphragm 21.
Further, here, an electrostatic actuator is configured by the diaphragm 21 and the individual electrode 32 arranged to face the diaphragm 21 with a certain distance (gap G) therebetween. The diaphragm 21 is displaced by electrostatic force generated by applying a voltage therebetween.

  The electrode substrate 3 is provided with an ink supply hole 34 connected to an ink cartridge (not shown). The ink supply hole 34 communicates with the reservoir 13 through the ink supply hole 26 provided in the vibration plate substrate 2.

Here, the operation of the inkjet head 200 configured as described above will be described.
Ink jet head 200 is supplied with ink in an external ink cartridge (not shown) into reservoir 13 through ink supply holes 34 and 26, and ink is further passed from individual orifices 14 through respective cavities 12 to nozzle holes. 11 is filled. A drive control circuit (not shown) such as a driver IC for controlling the operation of the inkjet head 10 is provided between each individual electrode 32 and a common electrode (not shown) provided on the diaphragm substrate 2. It is connected to the.

  Therefore, when a drive signal (pulse voltage) is supplied to the individual electrode 32 by this drive control circuit, a pulse voltage is applied to the individual electrode 32 from the drive control circuit, and the individual electrode 32 is positively charged, while corresponding to this. The vibrating plate 21 is negatively charged. At this time, since an electrostatic force (Coulomb force) is generated between the individual electrode 32 and the diaphragm 21, the diaphragm 21 is pulled toward the individual electrode 32 by this electrostatic force and bends. This increases the volume of the cavity 12. Next, when the pulse voltage is turned off, the electrostatic force disappears, and the vibration plate 21 returns to its original state due to its elastic force. At this time, the volume of the cavity 12 rapidly decreases. A part of the ink in the inside is ejected from the nozzle hole 11 as ink droplets.

  According to the ink jet head 200 according to the second embodiment, substantially the same effects as those of the first embodiment can be obtained, and the actuator is an electrostatic actuator, so that the miniaturization can be achieved as compared with the case where a piezoelectric actuator is used. An inexpensive inkjet head having a high density and a large number of nozzles can be obtained because it is easy and has a simple structure.

  Next, a method for manufacturing the inkjet head 10 according to the second embodiment will be described with reference to FIGS. Note that the values of the substrate thickness, etching depth, temperature, pressure and the like shown below are merely examples, and the present invention is not limited to these values. Here, a manufacturing method of the flow path substrate 1 will be described, and a conventionally known method can be used as the manufacturing method of the diaphragm substrate 2 and the electrode substrate 3, and thus description thereof is omitted here.

(A) A flow path substrate 100 made of a single crystal silicon substrate having a thickness of 300 μm and a plane orientation (100) is prepared, and a thermal oxide film having a thickness of 2.8 μm is formed on the outer surface of the flow path substrate 100. 101 is formed. The first nozzle hole 11a, the second nozzle hole 11b, the third nozzle hole 11c, the cavity 12, the orifice 14, and the reservoir 13 are formed on the thermal oxide film 101 on the surface A to be bonded to the diaphragm substrate 2. The portions 111a, 111b, 111c, 112, 114, and 113 are opened by a photolithography method. At this time, etching is performed so that the remaining film thickness of the thermal oxide film 101 in each of the portions 111a, 111b, 111c, 112, 114, and 113 on the A plane has the following relationship.
The portion 111a that becomes the first nozzle hole 11a = 0 <the portion 111b that becomes the second nozzle hole 11b <the portion 111c that becomes the third nozzle hole 11c <the portion that becomes the cavity 12 112 = the portion that becomes the orifice 14 114 = the reservoir 13 Part 113

(B) Next, the portion 111a which becomes the first nozzle hole 11a on the A surface is dry-etched by ICP to about 100 μm.
(C) Next, an appropriate amount of the thermal oxide film 101 is removed by etching to open the portion 111b that becomes the second nozzle hole 11b, and the portion 111b that becomes the second nozzle hole 11b is etched by about 50 μm by dry etching using ICP. To do.

(D) Next, an appropriate amount of the thermal oxide film 101 is removed by etching to open the portion 111c to be the third nozzle hole 11c, and the portion 111c to be the third nozzle hole 11c is etched by about 170 μm by dry etching using ICP. To do.
(E) Then, the thermal oxide film 101 is removed by an appropriate amount to open the portion 112 that becomes the cavity 12, the portion 114 that becomes the orifice 14, and the portion 113 that becomes the reservoir 13, and is about 80 μm by dry etching using ICP. Etch. As a result, the cavity recess 12a and the orifice 14 are formed to a desired depth. The portion 113 which becomes the reservoir 13 is still being manufactured, and here, it is formed to the same depth as the cavity 12 and the orifice 14. At this time, the portion 111a that becomes the first nozzle hole 11a, the portion 111b that becomes the second nozzle hole 11b, and the portion 111c that becomes the third nozzle hole 11c are similarly dry-etched and penetrate the flow path substrate 100. Thus, the nozzle hole 11 is formed.
(F) Then, after removing the thermal oxide film 101, a thermal oxide film 120 having a thickness of 1.1 μm is formed again. This thermal oxide film 120 is used as a mask member when the remaining portion of the reservoir 13 is formed by wet etching in the next step (g).

(G) Next, the silicon mask substrate 130 in which the opening 131 is formed is brought into close contact with the A surface side of the flow path substrate base material 100, and the thermal oxide film 120 is dry-etched by RIE (Reactive Ion Etching). An opening 140 is formed in a portion corresponding to 13. By using dry etching as the etching here, of the thermal oxide film 120 formed on the entire flow path substrate base material 100, the thermal oxide film on the bottom portion of the portion where the reservoir 13 is formed halfway and becomes concave. Only a portion corresponding to the reservoir 13 can be accurately removed from 120.
(H) Next, the flow path substrate base material 100 is immersed in wet etching with a 25% KOH solution, and a portion that becomes the reservoir 13 is etched by about 170 μm to form a reservoir recess 13 a that becomes the reservoir 13.
(I) Then, after removing the thermal oxide film 120, a thermal oxide film 140 having a thickness of 0.1 μm is formed again as an ink protective film.
Thus, the flow path substrate 1 is manufactured.

  The ink jet head 200 is manufactured by adhering the bonded substrate obtained by bonding the vibration plate substrate 2 and the electrode substrate 3 to the flow channel substrate 1 manufactured in this manner with an adhesive.

  As described above, in the method of manufacturing the inkjet head 10 according to the second embodiment, substantially the same operational effects as those of the first embodiment can be obtained, and the depth of the cavity 12 can be increased when the reservoir 13 having a large etching amount is formed. Since the cavity 12 is formed by dry etching at the same time as the manufacturing process and the remaining portion of the reservoir 13 is formed by wet etching, the reservoir 13 can be formed efficiently and with high throughput as compared with the first embodiment.

  Further, since the thermal oxide film 120 is used as a mask member when the remaining portion of the reservoir 13 is formed by wet etching, a dense and uniform mask can be formed with good throughput.

  In addition to the ink jet printer shown in FIG. 9, the ink jet heads 10 and 200 according to each of the above embodiments can be used to manufacture liquid crystal display color filters and light emitting portions of an organic EL display device by variously changing droplets. The present invention can be applied to a droplet discharge apparatus for various uses such as formation of a wiring board, formation of a wiring portion of a wiring board manufactured by a printed wiring board manufacturing apparatus, and discharge of a biological liquid (manufacture of a protein chip and a DNA chip). In addition, the droplet discharge device including the ink jet head (droplet discharge head) according to the first and second embodiments described above prevents droplet interference between the nozzles that occurs during droplet discharge, and has excellent discharge characteristics. It can be set as the droplet discharge device provided with the head.

FIG. 2 is an exploded perspective view illustrating a schematic configuration of the inkjet head according to the first embodiment. Sectional drawing which shows the assembly state of the inkjet head of FIG. Sectional drawing of the manufacturing process of the flow-path board | substrate of FIG. Sectional drawing of the manufacturing process of the flow-path board | substrate following FIG. FIG. 4 is an exploded perspective view showing a schematic configuration of an inkjet head according to a second embodiment. FIG. 6 is a longitudinal sectional view showing an assembled state of the ink jet head of FIG. 5. Sectional drawing of the manufacturing process of the flow-path board | substrate of FIG. Sectional drawing of the manufacturing process of the flow-path board following FIG. 1 is a perspective view showing an ink jet printer according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Flow path board | substrate, 2 Vibration board substrate, 10 Inkjet head, 11 Nozzle hole, 12 Cavity, 12a Cavity recessed part, 13 Reservoir, 13a Reservoir recessed part, 14 Orifice, 21 Vibration board, 22 Piezoelectric element, 32 Individual electrode, 100 Flow path substrate base material, 101 thermal oxide film, 120 thermal oxide film, 131 opening, 200 inkjet head.

Claims (12)

A plurality of nozzle holes, a plurality of cavity recesses that communicate with each of the nozzle holes, generate pressure inside, and serve as cavities for discharging droplets from the nozzle holes, and the same cavity side as the cavity recesses A channel substrate formed with a reservoir recess that serves as a reservoir for storing droplets to be supplied to the cavity recess, and a plurality of orifices that communicate the cavities with the reservoir;
A diaphragm substrate having a diaphragm bonded to the channel substrate and generating pressure in a cavity of the channel substrate;
A droplet discharge head, comprising: an actuator that deforms the diaphragm and applies a pressure change in the cavity.   The actuator is a piezoelectric actuator that applies a voltage to a piezoelectric element formed on a surface of the diaphragm opposite to the flow path substrate and deforms the diaphragm by deformation of the piezoelectric element. The droplet discharge head according to claim 1.   The actuator is an electrostatic actuator that generates an electrostatic force by applying a voltage between the diaphragm and an electrode spaced apart from the diaphragm and uses the electrostatic force to deform the diaphragm. The droplet discharge head according to claim 1, wherein the droplet discharge head is provided.   The nozzle hole is formed so as to be gradually or gradually reduced from a joint surface of the flow path substrate to the diaphragm substrate toward a surface on the opposite side. 4. The droplet discharge head according to any one of 3 above.   5. The droplet discharge head according to claim 1, wherein a depth of the reservoir recess is deeper than a depth of the cavity recess. 6.   6. The droplet discharge head according to claim 1, wherein a depth of the orifice is the same as that of the concave portion for the cavity, and a width of the orifice is smaller than that of the concave portion for the cavity. . A method for manufacturing a droplet discharge head according to any one of claims 1 to 6,
When the nozzle hole, the cavity, the reservoir, and the orifice are formed on the flow path substrate base material, the flow path substrate is formed using one mask member in which all corresponding opening patterns are formed. A method of manufacturing a droplet discharge head, wherein the substrate is formed by dry etching from one side. A method for manufacturing a droplet discharge head according to any one of claims 1 to 6,
When forming the nozzle hole, the cavity, a part of the reservoir, and the orifice on the flow path substrate base material, using one mask member in which all corresponding opening patterns are formed, Forming the flow path substrate base material by dry etching from one side, and then forming the remaining portion of the reservoir by wet etching using a mask member different from the mask member from the same one side as described above. A manufacturing method of a droplet discharge head characterized by the above.   9. The method of manufacturing a droplet discharge head according to claim 7, wherein the mask member used when etching the flow path substrate base material is a thermal oxide film.   The mask member used when the remaining portion of the reservoir is formed on the flow path substrate base material by wet etching has an opening formed in a portion corresponding to the reservoir, and when the opening is formed, After forming a thermal oxide film on the entire surface of the flow path substrate base material after forming a part, a mask substrate having an opening corresponding to the reservoir is brought into close contact with the reservoir formation surface side of the flow path substrate base material, 10. The method of manufacturing a droplet discharge head according to claim 9, wherein the thermal oxide film is formed by dry etching.   The method of manufacturing a droplet discharge head according to claim 10, wherein RIE is used for dry etching of the thermal oxide film.   A droplet discharge apparatus comprising the droplet discharge head according to any one of claims 1 to 6.

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