JP2009023097A - Manufacturing method of fluid passage substrate, manufacturing method of droplet discharge head, and manufacturing method of droplet discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a fluid passage substrate, in which high productivity is attained while a nozzle is formed with high accuracy, and the like. <P>SOLUTION: The manufacturing method of the fluid passage substrate has: a process of forming a resist on at least one surface of a silicon substrate 100 and etching and patterning the resist of a part serving as a plurality of nozzles 11, a plurality of first recessed portions 12a and a second recessed portion 13a; a process of forming the plurality of nozzles 11 and the plurality of first recessed portions 12a by anisotropic dry etching; a process of forming a dummy pattern 115 in a part serving as the second recessed portion 13a and oxidizing the dummy pattern 115; and a process of removing the oxidized dummy pattern by wet etching and forming the second recessed portion 13a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a channel substrate on which a channel for discharging droplets is formed, a droplet discharge head using the channel substrate, and a method for manufacturing a droplet discharge apparatus having the droplet discharge head. .

For example, microfabrication technology (MEMS: Micro) that forms fine elements by processing silicon, etc.
Electro Mechanical Systems) has made rapid progress. Examples of microfabricated elements formed by microfabrication technology include, for example, a droplet discharge head (inkjet head), a micropump, and an optical variable filter used in a recording (printing) apparatus such as a droplet discharge type printer. There are electrostatic actuators such as motors, pressure sensors and the like.

Here, a droplet discharge head that is an electrostatic actuator will be described as an example of a microfabricated element. A droplet discharge type recording (printing) apparatus is used for printing in various fields regardless of whether it is for home use or industrial use. In the droplet discharge method, for example, a droplet discharge head having a plurality of nozzles is moved relative to an object, and droplets are discharged to a predetermined position of the object to record printing or the like. . This system is a microarray of biomolecules such as color filters for producing display devices using liquid crystals, display panels (OLEDs) using electroluminescence elements such as organic compounds, DNA, proteins, etc. Etc. are also used in the manufacture of

And when manufacturing the droplet discharge head used in the apparatus, the nozzle,
A plurality of substrates in which recesses or the like to be flow paths are formed on a silicon substrate or the like are stacked and bonded.
A flow path substrate made of single crystal silicon (hereinafter simply referred to as silicon), including a plurality of nozzles, and a flow path member serving as a liquid flow path to each nozzle, a diaphragm for pressurizing the flow path, and There is a droplet discharge head manufactured by stacking a base substrate provided with a piezoelectric element for vibrating a diaphragm (see, for example, Patent Document 1). When manufacturing a droplet discharge head,
The nozzle and the flow path member are formed by repeating film formation, patterning, etching and the like on the silicon substrate.
JP 2003-326724 A (page 4, FIG. 4)

Here, consider the case where the nozzle and the flow path member are formed on one substrate as described above.
For a nozzle that directly affects the ejection characteristics, it is better that the size, shape, etc. can be formed with high accuracy. To that end, anisotropic dry etching (hereinafter referred to as dry etching)
Thus, it is desirable to form a nozzle, a hole to be a flow path member, a recess, and the like. Further, in the case of dry etching, etching can be performed in the vertical direction without being affected by the crystal plane orientation of the silicon substrate, so that the expansion of the flow path member can be suppressed and the interval between the plurality of nozzles can be reduced. Therefore, it is possible to meet the demand for higher density.

On the other hand, in order to temporarily store the liquid supplied from outside the droplet discharge head, a reservoir (common liquid chamber) is formed as a flow path member. Since this reservoir is a member common to each nozzle, the area (volume) occupied in the flow path substrate is large.

Basically, since both the nozzle and the reservoir are formed by etching the substrate, the formation of the nozzle and the formation of the reservoir are considered in consideration of the patterning of the resist and the like, the number of times of etching, and the restrictions on the crystal plane orientation of the reservoir volume. It is desirable that the same etching process can be used.

However, if the reservoir is also formed by dry etching, a large area of silicon must be etched. As a characteristic of dry etching, an etching rate is lower as etching is performed in a larger area. Therefore, the formation of the reservoir takes time compared to the formation of the nozzle. In addition, since a large area is etched, the consumption of process gas required for etching increases. From the above, it has been difficult to improve productivity in forming the nozzle and the flow path member.

Accordingly, in order to solve the above-described problems, the present invention provides a method for manufacturing a flow path substrate, a method for manufacturing a droplet discharge head, and a method for improving productivity while processing and forming a high-precision nozzle. An object of the present invention is to provide a method for manufacturing a droplet discharge device.

The flow path substrate manufacturing method according to the present invention includes a plurality of nozzles, a first recess serving as a plurality of cavities communicating with each nozzle, and a second recess serving as a reservoir communicating with the plurality of cavities. A method of manufacturing a flow path substrate to be formed on a silicon substrate, comprising: forming a resist on at least one surface of the silicon substrate; and etching the resist in a portion that becomes a plurality of nozzles, a plurality of first recesses, and a second recess Patterning, forming a plurality of nozzles and a plurality of first recesses by anisotropic dry etching, forming a dummy pattern in a portion to become the second recess, and oxidizing the dummy pattern And a step of removing the oxidized dummy pattern by wet etching to form a second recess.
According to the present invention, the silicon substrate is subjected to anisotropic etching after patterning only a part of the portion serving as the reservoir recess serving as the second recess and reducing the etching area. The remaining dummy pattern is oxidized and removed by wet etching, so that the volume of the reservoir can be increased regardless of the crystal plane orientation. Further, since the etching area (volume) can be reduced, the time required for forming a reservoir having a large area (volume) can be shortened by maintaining the etching rate (suppressing the reduction). In addition, the consumption of process gas can be suppressed and environmental considerations can be made. In order to remove the oxidized dummy pattern by wet etching, so-called batch processing can be performed in which a plurality of substrates are processed at once. As described above, the productivity can be remarkably improved as compared with the manufacture of the flow path substrate using the normal anisotropic dry etching.

In the method for manufacturing a flow path substrate according to the present invention, the plurality of nozzles are formed to have a plurality of stages in which the hole diameter decreases toward the direction in which the liquid is discharged, and the dummy pattern in the portion that becomes the second recess Is formed by the same process as anisotropic dry etching for forming at least one stage of a plurality of stages of nozzles.
According to the present invention, by forming a plurality of nozzles, it is possible to improve the straightness of the liquid droplets to be discharged and to improve the discharge characteristics. In forming a plurality of nozzles in this multi-stage nozzle formation, anisotropic dry etching is simultaneously performed on the portion that becomes the reservoir recess, which is the second recess, so that the time can be further reduced. Can do.

In the method for manufacturing a flow path substrate according to the present invention, anisotropic dry etching is performed by RIE.
According to the present invention, highly accurate anisotropic etching can be performed by performing anisotropic dry etching by RIE.

In the method for manufacturing a flow path substrate according to the present invention, anisotropic dry etching is performed by ICP discharge.
According to the present invention, by performing anisotropic dry etching by ICP discharge, the processing accuracy in the vertical direction of the silicon substrate can be further increased.

In addition, a method for manufacturing a droplet discharge head according to the present invention joins a flow path substrate manufactured by the above-described flow path substrate manufacturing method and one or more substrates serving as an actuator for pressurizing a liquid. It further has a process.
According to the present invention, since the substrate serving as the actuator is joined to the flow path substrate on which the flow path member is formed by anisotropic dry etching as described above, the droplet discharge head is manufactured. Processing can be performed, and a droplet discharge head with good discharge characteristics can be manufactured.

Further, the method for manufacturing a droplet discharge head according to the present invention includes a diaphragm substrate having a plurality of diaphragms for pressurizing a liquid and a plurality of piezoelectric elements for displacing the plurality of diaphragms.
Bonded to the flow path substrate.
According to the present invention, since the diaphragm substrate having the diaphragm and the piezoelectric element as the actuator is bonded to the flow path substrate, the piezoelectric element can obtain a large displacement of the diaphragm and realize high output driving. can do.

The method for manufacturing a droplet discharge head according to the present invention includes a diaphragm substrate having a plurality of diaphragms for pressurizing a liquid, and a plurality of diaphragms facing each other and an electrostatic force between each diaphragm. An electrode substrate having a plurality of fixed electrodes that generate a displacement and displace each diaphragm is joined to the flow path substrate.
According to the present invention, the vibration plate and the fixed electrode are used as the actuator, and the vibration plate substrate and the electrode substrate are joined to the flow path substrate. Therefore, it is possible to manufacture a liquid droplet ejection head that is inexpensive and has low power consumption. it can.

The manufacturing method of the droplet discharge device according to the present invention applies the above-described manufacturing method of the droplet discharge head to manufacture the droplet discharge device.
According to the present invention, since the droplet discharge device is manufactured by applying the above-described method for manufacturing a droplet discharge head, it is possible to manufacture a droplet discharge device having high droplet discharge performance and high reliability. it can.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a state in which the droplet discharge head according to Embodiment 1 of the present invention is disassembled. FIG. 2 is a longitudinal sectional view showing a sectional configuration of the droplet discharge head. 1 and 2
The configuration and operation of the droplet discharge head will be described based on FIG. This droplet discharge head
As a representative example of a piezoelectric drive type actuator (drive means), a face eject type droplet discharge head that discharges droplets from nozzle holes provided on the surface side of a flow path substrate is shown as an example. In addition, in the following drawings including FIG. 1, in order to make each component member easy to see, there is a case where the relationship of the size of each component member is different from the actual one.

As shown in FIGS. 1 and 2, the droplet discharge head includes a flow path substrate (nozzle plate) 10.
And the diaphragm substrate 20 are laminated and joined. As shown in FIGS. 1 and 2, a reservoir 13, an orifice 14, a cavity 12, and a nozzle 11 are processed and formed as a flow path member provided on the flow path of the liquid on the flow path substrate 10 constituting the droplet discharge head. Has been. Here, it is assumed that the flow path substrate 10 has a predetermined thickness (for example, 200 μm or more) in order to ensure a predetermined volume for the reservoir 13.

The flow path substrate 10 is made of, for example, a silicon substrate having a thickness of 300 μm and a crystal surface orientation of the substrate surface of (100). A plurality of nozzles 11 are vertically formed in the flow path substrate 10 at a predetermined pitch. Each nozzle 11 is formed so as to decrease stepwise or gradually from the joint surface (processed surface) to the diaphragm substrate 20 toward the opposite surface (discharge surface). In the first embodiment, the first nozzle 11a, the second nozzle 11b, and the third nozzle 11c have a three-stage configuration in order from a hole having a smaller diameter, assuming that the diameter is gradually reduced. And By comprising in this way, the increase in channel resistance by the nozzle length becoming long can be suppressed. Further, since the nozzle diameter becomes smaller toward the ejection surface, the straightness in the droplet ejection direction can be improved by the rectifying action.

Further, in the flow path substrate 10, the joint surface with the diaphragm substrate 20 communicates independently with each nozzle 11, and becomes a cavity 12 that generates pressure inside and discharges droplets from each nozzle 11. A plurality of orifices 1 communicating with each of the cavities 12 and the reservoir 13, and a second recess 13a serving as a reservoir 13 for storing a liquid to be supplied to each cavity 12.
4 are formed. The width of the orifice 14 is preferably smaller than the width of the first recess 12a in order to adjust the flow path resistance. Further, a liquid protective film 15 made of, for example, silicon oxide is formed on the surface of the flow path substrate 10 in order to prevent the flow path substrate 10 from being eroded by the liquid.

The diaphragm substrate 20 is made of stainless steel having a thickness of 30 μm, for example. Diaphragm substrate 2
In 0, the part facing the cavity 12 is the diaphragm 21, and the piezoelectric element 22 is provided on the surface of the diaphragm 21 opposite to the surface facing the cavity 12. Piezoelectric element 2
2 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 the first embodiment, the case where the lower electrode film 25 is the common electrode of the piezoelectric element 22 and the upper electrode film 24 is the individual electrode of the piezoelectric element 22 is shown as an example. May be reversed. A liquid protective film 27 is also formed on the surface of the vibration plate substrate 20 that is joined to the flow path substrate 10.

Further, the liquid in the external cartridge (not shown) is supplied to the diaphragm substrate 20 from the flow path substrate 10.
A liquid supply hole 26 is formed to penetrate the reservoir 13. The liquid supply hole 26 may be formed through at a position corresponding to the reservoir 13 formed in the flow path substrate 10.
In the following description, the piezoelectric element 22 and the vibration plate 21 that is displaced by driving the piezoelectric element 22 may be collectively referred to as a piezoelectric actuator. Here, the case where the diaphragm substrate 20 is made of stainless steel is described as an example.
The constituent materials are not particularly limited.

Here, the operation of the droplet discharge head will be described. In the droplet discharge head, the liquid in the external cartridge is supplied to the reservoir 13 through the liquid supply hole 26. This liquid
It is supplied to each cavity 12 through each orifice 14. And the nozzle 11
It will be filled with liquid up to the tip. Note that a drive control circuit (not shown) such as a driver IC for controlling the operation of the droplet discharge head has 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 and. 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 23, and the diaphragm 21 are deformed and the pressure in the cavity 12 increases,
A droplet is discharged from the nozzle 11.

Next, a method for manufacturing the flow path substrate 10 of the droplet discharge head according to the first embodiment will be described with reference to FIGS. In addition, the thickness and etching depth of the substrate shown below, temperature,
Values such as pressure are merely examples, and the present invention is not limited to these values. Here, a method for manufacturing the flow path substrate 10 will be described. Since a conventionally known manufacturing method can be used for the manufacturing method of the diaphragm substrate 20 having the piezoelectric element 22, the description thereof is omitted.

For example, a silicon substrate 100 having a thickness of 300 μm and a plane orientation (100) to be the flow path substrate 10.
And a resist 101 made of a silicon oxide film having a thickness of 2.8 μm is formed on the surface of the silicon substrate 100. This silicon oxide film is formed by a method such as wet thermal oxidation performed in a mixed atmosphere of water vapor and oxygen, for example. Then, the first nozzle 11 a, the second nozzle 11 b, and the third nozzle 11 are formed on the resist 101 on the flow path surface on the side to be joined to the diaphragm substrate 20.
c, respective portions 111a, 111b, 111c, 112, 114, 113 to be the first recess 12a (cavity 12), the orifice 14, and the second recess 13a (reservoir 13).
Is patterned by photolithography (FIG. 3A).

Here, all of the resist 101 in the portion 111a to be the first nozzle 11a is removed to expose the silicon substrate 100, but the other portion is half-etched to leave a part of the resist 101. At this time, each portion 111a, 11 of the resist 101 on the flow path surface.
The remaining film thickness of the resist 101 of 1b, 111c, 112, 114, 113 is the first nozzle 1
1a becomes a portion 111a = 0 <second nozzle 11b becomes a portion 111b <third nozzle 11c
Patterning by half-etching is performed so that the portion 111c to become the portion 113 to become the second recess 13a <the portion 112 to become the first recess 12a = the portion 114 to become the orifice 14. As for the size of patterning, in consideration of the thickness of the thermal oxide film 102 to be formed later, patterning is performed smaller than the size of the channel member to be finally formed.
In particular, it is necessary to pay attention to the portion 111a that becomes the first nozzle 11a because it is necessary to control the hole diameter (herein, the diameter) with high accuracy.

FIG. 5 is a diagram illustrating an example of patterning performed on the portion 113 to be the second recess 13a.
As shown in FIGS. 3 and 5, the portion 113 to be the second recess 13a is not patterned by half-etching on the entire surface, but is patterned on the peripheral portion and the inner portion. Thus, the patterning portion 113a is formed. Therefore, dry etching is performed on the patterning portion 113a. Thus, the second
By performing dry etching on the patterning portion 113a instead of the entire surface of the portion 113 that becomes the concave portion 13a, the area (volume) of the portion where dry etching is performed can be reduced, and the reservoir 13 (second concave portion 13a) can be reduced. ), The time spent for dry etching can be reduced without reducing the etching rate. In addition, the consumption of process gas (eg, carbon tetrafluoride (CF ₄ ), sulfur hexafluoride (SF ₆ ), etc.) can be reduced. Here, a portion remaining without being etched is a dummy pattern 115. Therefore, in FIG. 5A, a lattice-like dummy pattern is formed, and in FIG. 5B, a ring-like dummy pattern is formed. Here, D _w in FIG. 5 represents the length of the dummy pattern 115 as will be described later.

As described above, it is useful to reduce the area of the portion where dry etching is performed. However, when the area to be etched is small (the portion remaining as the dummy pattern 115 increases), the portion where dry etching is performed is dense (for example, width). Is likely to be narrow). When the portion to be dry-etched becomes dense, the process gas metabolism becomes worse, and a microloading effect is generated in which the etching rate is lowered. Therefore, even if the area to be etched is too small, time is conversely spent. Further, as will be described later, the dummy pattern 11
Since the time for wet thermal oxidation of 5 and the time for wet etching increase, in some cases, the patterning portion 113a is patterned so that the entire manufacturing process can be shortened in balance with these times. You should do it. Further, in order to prevent the pattern from becoming dense, the patterning portion 11 is provided with a certain width as evenly as possible.
3a is formed and patterned (a dummy pattern 115 is formed).

Next, dry etching is performed in the order of deep formation. Here, RIE (Reactive Ion Etching), which enables anisotropic etching with high accuracy, is performed, and in particular, dry etching (ICP (Inductively Coupled Plasma) discharge) is used.
Hereinafter, it is referred to as “ICP dry etching”. ICP dry etching
Since the processing accuracy when etching is performed in a direction perpendicular to the substrate is particularly high, it is suitable for forming the flow path member at a high density. First, the part 111 which becomes the 1st nozzle 11a of a flow-path surface.
a is etched by about 100 μm by ICP dry etching (FIG. 3B). Furthermore, the resist 111 is removed by an appropriate amount, and a portion 111b that becomes the second nozzle 11b.
The silicon substrate 100 is exposed, and the portion 111b that becomes the second nozzle 11b is etched by about 50 μm by ICP dry etching (FIG. 3C).

Next, an appropriate amount of the resist 101 is removed by etching to form a portion 111 that becomes the third nozzle 11c.
The silicon substrate 100 of the portion 113 that becomes c and the second recess 13a is exposed, and the portion 111c that becomes the third nozzle 11c and the patterning portion 113a of the portion 113 that becomes the second recess 13a are etched by about 170 μm by ICP dry etching. Processing is performed (FIG. 3D). At this time, as for the portion 113 to be the second recess 13a, only the portion where the silicon substrate 100 is exposed is etched. The portion that has not been etched is left as a dummy pattern 115.

Further, the resist 11 is etched away by an appropriate amount to form a portion 11 that becomes the first recess 12a.
2 and the portion 114 that becomes the orifice 14 are exposed, and the portion 112 that becomes the first recess 12a and the portion 114 that becomes the orifice 14 are etched by about 80 μm by ICP dry etching (FIG. 4E). Here, the portion 1 which becomes the first recess 12a
12 and the portion 114 that becomes the orifice 14 are etched, but the portion 113 that becomes the second recess 13a may be further etched.

Then, after removing the resist 101, a thermal oxide film 102 is formed again by wet thermal oxidation on the entire surface of the silicon substrate 100 (FIG. 4F). This thermal oxide film 102 is formed to remove the dummy pattern 115. In wet thermal oxidation, silicon and oxygen are reacted to produce silicon oxide. This silicon is obtained from the silicon substrate 100. Therefore, the thermal oxide film 102 grows while consuming silicon of the silicon substrate 100. At this time, it is generally known that the thickness of the surface of the silicon substrate 100 consumed for the growth of the oxide film is about 45% of the thickness of the grown thermal oxide film 102. Therefore, when the thickness of the silicon substrate 100 consumed by wet thermal oxidation is ΔD _Si and the thickness of the thermal oxide film 102 is ΔT _SiO2 , the relationship shown in the following equation (1) is established.
ΔD _Si = ΔT _SiO2 × 0.45 (1)

Here, assuming that the thermal oxide film 102 is formed from the entire side surface of the dummy pattern 115, the thickness ΔT _SiO2 of the thermal oxide film 102 for converting the silicon remaining as the dummy pattern 115 into silicon oxide by wet thermal oxidation. Is the dummy pattern 115 described above.
The length D _w of the would be represented by the following formula (2). Here, the dummy pattern 11
The length D _w of the 5, grid-like as shown in FIG. 5, since it is formed in a ring shape, a long portion of the grid width, but the ring width, for example, in the case where the dummy pattern 115 remains in circles Represents the diameter. Further, when the dummy pattern 115 is rectangular, it represents the length of the short side,
In the case of a square, it represents the length of one side.
D _w = ΔD _Si × 2 = ΔT _SiO2 × 0.45 × 2
ΔT _SiO2 = D _w /0.9 (2)

From the above, the following equation (3) is established.
ΔT _SiO2 ≧ D _w /0.9 (3)

Here, the thermal oxide film 102 is formed on the entire surface of the silicon substrate 100. Therefore, the hole diameter of the first nozzle 11a is expanded. Therefore, the thickness ΔT _SiO2 of the thermal oxide film 102 formed by wet thermal oxidation is determined in consideration of the hole diameter of the first nozzle 11a. At this time,
The hole diameter of the first nozzle 11a before thermal oxide film 102 is formed, when the difference between the pore diameter after forming the .DELTA.N _D, the length D _w of the dummy pattern 115, in relation to the .DELTA.N _D, the following equation (4 It is desirable to decide as shown in FIG.
ΔN _D /0.9=ΔT _SiO2 ≧ D _w /0.9
_{ΔN D ≧ D w ... (4} )

FIG. 6 is a diagram showing wet thermal oxidation conditions in relation to oxidation temperature, oxidation time, and oxide film thickness. For example, the silicon substrate 100, in case of performing wet thermal oxidation in an atmosphere of temperature of 1000 ° C., when a 1μm to .DELTA.N _D, a thermal oxide film to be deposited from (4) 102
The thickness ΔT _SiO2 is 1.1 μm. It can also be seen from FIG. 6 that the required oxidation time is 340 minutes. At this time, the length D _w of the dummy pattern 115 is composed of 1μm or less.

By forming the thermal oxide film 102 by wet thermal oxidation, the silicon of the dummy pattern 115 is oxidized to become silicon oxide. Thereafter, the thermal oxide film 102 is removed (FIG. 4G).
Thereby, the dummy pattern 115 is removed and the reservoir 13 is formed. Here, depending on the degree of oxidation of the dummy pattern 115, the second recess 13a constituting the reservoir 13 is used.
There may be some unevenness on the bottom part of the. Normally, it is considered that treatment for such unevenness is not necessary. However, for example, if the unevenness is large, there is a possibility that the liquid flow will be bad and bubbles that have entered the reservoir 13 may not be removed. Depending on the case, a process for smoothing the bottom surface may be performed. After removing the thermal oxide film 102 as described above, the liquid protective film 15 having a thickness of 0.1 μm is formed again (FIG. 4H).

The droplet substrate is manufactured by adhering (bonding) the diaphragm substrate 20 having the piezoelectric element 22 and the liquid supply hole 26 formed thereon with an adhesive such as an epoxy resin to the flow path substrate 10 thus manufactured. .

As described above, according to the first embodiment, the nozzle 11, the cavity 12, and the reservoir 13
Are formed on a single flow path substrate 10 and the two substrates of the flow path substrate 10 and the diaphragm substrate 20 are laminated and joined, so that the number of substrates is reduced and the flow path member is By consolidating, member costs and assembly costs can be reduced. In addition, since the cavity 12 and the diaphragm 21 are formed of different substrates, compared with the structure in which the bottom surface of the cavity 12 is the diaphragm 21,
The thickness of the flow path substrate 10 can be freely selected without being restricted by the depth of the cavity 12 and the thickness of the diaphragm 21. For this reason, by selecting a substrate having a sufficient thickness as the flow path substrate 10, it is possible to secure a sufficient reservoir volume to prevent crosstalk while ensuring an optimum depth of the cavity 12 for ejection. it can. In addition, since the diaphragm 21 is displaced by the piezoelectric element 22, the displacement of the diaphragm 21 can be easily increased, and high output driving can be achieved.

Furthermore, in the first embodiment, since the flow path member of the flow path substrate 10 is formed by dry etching when manufacturing the droplet discharge head, each member can be formed with high accuracy. . Further, since the flow path member can be formed in a direction perpendicular to the substrate surface, it is not affected by the crystal plane orientation and does not have an oblique angle. For example, the density can be increased. Further, the volume of the reservoir 13 can be increased.

Then, the entire portion 113 to be the reservoir 13 is not formed by dry etching, but a part thereof is left as a dummy pattern 115, and the dummy pattern 115 is formed by wet thermal oxidation.
The area (volume) for dry etching can be reduced and the area (volume) can be increased by maintaining the etching rate (suppressing the reduction). The time required for forming the reservoir 13 can be shortened. Also, by reducing the area (volume) for dry etching, process gas consumption is reduced,
Environmental considerations can also be made. Further, since the oxidized dummy pattern 115 can be removed by using wet etching, so-called batch processing can be performed in which a plurality of substrates are processed at once. As described above, the productivity of the droplet discharge head (channel substrate) using dry etching can be improved.

Embodiment 2. FIG.
FIG. 7 is an exploded perspective view showing a state in which the droplet discharge head according to Embodiment 2 of the present invention is disassembled. FIG. 8 is a longitudinal sectional view showing a sectional configuration of the droplet discharge head. 7 and 8
The configuration and operation of the droplet discharge head will be described based on FIG. This droplet discharge head
As a representative of an electrostatic drive type actuator (driving means), a face eject type droplet discharge head that discharges droplets from nozzle holes provided on the surface side of a flow path substrate is shown as an example. In the second embodiment, the differences from the first embodiment will be mainly described, and the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 7 and 8, the droplet discharge head according to the second embodiment has a flow path substrate (nozzle plate) 10, a vibration plate substrate (cavity plate) 20a, and an electrode substrate 30 stacked in order and bonded. It is composed.

The diaphragm substrate 20a in the present embodiment is a substrate formed using, for example, silicon. Further, on the surface of the diaphragm substrate 20a on the electrode substrate 30 side, for example, TEOS (Tetr
An insulating film 28 is formed to a thickness of, for example, 0.1 μm from silicon oxide by plasma CVD (Chemical Vapor Deposition) using aethylorthosilicate Tetraethoxysilane (tetraethoxysilane, ethyl silicate) as a raw material. This insulating film 28 is provided in order to prevent dielectric breakdown and short circuit when the droplet discharge head is driven.

An electrode substrate 30 is bonded to the surface of the diaphragm substrate 20a opposite to the surface to which the flow path substrate 10 is bonded. The material of the electrode substrate 30 is not particularly limited, but in the present embodiment, the electrode substrate 30 is made of, for example, glass having a thickness of about 1 mm.
The electrode substrate 30 includes each diaphragm 21 of the diaphragm substrate 20 a and each cavity 1 of the flow path substrate 10.
An electrode recess (third recess) 31 is formed at a position facing 2. Each electrode recess 31 may be formed to a depth of about 0.3 μm, for example, by etching. And
In general, individual electrodes 32 made of ITO (Indium Tin Oxide) are formed on the bottom surface of each electrode recess 31 by sputtering or the like with a thickness of 0.1 μm, for example. Further, the electrode substrate 30 is provided with a liquid supply hole 34 communicating with the liquid supply hole 26 formed in the vibration plate substrate 20a. The liquid supply hole 34 is the liquid supply hole 26 of the diaphragm substrate 20a.
Through the reservoir 13.

Here, when the individual electrode 32 is made of ITO, it is transparent in the visible light region.
It is easy to check the contact state of the diaphragm 21 after manufacture. However, it is not limited to this. For example, IZO (Indium Zinc Oxide) or gold (Au)
Alternatively, a metal such as copper (Cu) may be used.

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. A 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 28 covering the individual electrode 32 and the diaphragm 21. Become. Since this gap G greatly affects the ejection characteristics of the droplet ejection head, strict accuracy control is required. In the second embodiment, a case where the gap G is 0.2 μm will be described as an example. The open end of the gap G is hermetically sealed with a sealing material 33 made of an epoxy adhesive or the like. As a result, foreign matter, moisture, and the like can be prevented from entering the gap G, and the reliability of the droplet discharge head can be kept high.

Next, the operation of the droplet discharge head in this embodiment will be described. In the droplet discharge head, liquid from an external cartridge (not shown) is supplied to the liquid supply hole 34 and the liquid supply hole 2.
6 through the reservoir 13. This liquid is supplied to each cavity 12 and nozzle 11 through each orifice 14. Then, the tip of the nozzle 11 is filled with the liquid. A driver I for controlling the operation of the droplet discharge head
A drive control circuit (not shown) made of C or the like is connected between each individual electrode 32 and a common electrode (not shown) provided on the diaphragm substrate 20a.

Accordingly, a drive signal (pulse voltage) is applied to the individual electrode 32 selected by the drive control circuit, and the individual electrode 32 is charged positively (positively). On the other hand, at this time, a negative polarity charge is supplied to the diaphragm 21 via the common electrode, and the positively charged individual electrode 3 is supplied.
The diaphragm 21 at a position corresponding to 2 is relatively negatively charged. Therefore, an electrostatic force (Coulomb force) is generated between the selected individual electrode 32 and the diaphragm 21. If it does so, the diaphragm 21 will be drawn near to the individual electrode 32 side by an electrostatic force, and will be bent. This increases the volume of the cavity 12.

Thereafter, when the pulse voltage to the individual electrode 32 is turned off, the electrostatic force between the diaphragm 21 and the individual electrode 32 disappears, and the diaphragm 21 is restored to the original state by the elastic force. At this time, since the volume of the cavity 12 decreases rapidly, the pressure inside the cavity 12 increases rapidly. As a result, a part of the liquid in the cavity 12 is discharged as a droplet from the nozzle 11. For example, printing is performed by the droplets landing on a recording sheet, for example. Thereafter, a droplet is discharged from the reservoir 13 through the orifice 14 into the cavity 1.
2 is replenished to return to the initial state.

According to the droplet discharge head according to the second embodiment, it is possible to obtain substantially the same operational effects as the droplet discharge head according to the first embodiment. Further, since the actuator as the driving means is an electrostatic actuator, it can be easily miniaturized and the structure can be simplified as compared with the case where the piezoelectric actuator of the first embodiment is used. Therefore, a droplet discharge head in which a large number of nozzles 11 are formed at a high density can be manufactured at a relatively low cost.

Embodiment 3 FIG.
In the above embodiment, ICP dry etching is used as dry etching, but the present invention is not limited to this. You may make it perform dry etching by other RIE. RIE dry etching is effective when accuracy is required. Therefore, you may make it utilize especially when forming the 1st nozzle 11a which requires a highly accurate etching process.

Embodiment 4 FIG.
FIG. 9 is an external view of a droplet discharge apparatus using the droplet discharge head manufactured in the above embodiment. FIG. 10 is a diagram showing an example of main constituent means of the droplet discharge device. 9 and 1
The zero droplet discharge device 200 is intended for printing by a droplet discharge method (inkjet method). Further, it is a so-called serial type device. In FIG. 10, recording is performed by ejecting ink to the drum 201 on which the printing paper 210 that is the printing object is supported, and the printing paper 210.
It is mainly composed of the droplet discharge head 202 described in the above embodiment. Although not shown, there is an ink supply means such as an ink cartridge for supplying ink to the droplet discharge head 202. The print paper 210 is held by being pressed against the drum 201 by a paper press roller 203 provided in parallel to the axial direction of the drum 201. And feed screw 2
04 is provided parallel to the axial direction of the drum 201, and the droplet discharge head 202 is held. As the feed screw 204 rotates, the droplet discharge head 202 moves in the axial direction of the drum 201.

On the other hand, the drum 201 is rotationally driven by a motor 206 via a belt 205 or the like.
The print control means 207 such as a drive control circuit drives the feed screw 204 and the motor 206 based on the print data and the control signal. Although not shown here, an oscillation circuit that constitutes the drive control circuit The vibration plate is vibrated, and printing is performed on the print paper 210 while being controlled.

Here, the liquid is ejected onto the print paper 210 as ink, but the liquid ejected from the droplet ejection head is not limited to ink. For example, in an application to be discharged onto a substrate to be a color filter, a liquid containing a pigment for a color filter, an application to be discharged to a display substrate such as an OLED, an application to be wired on a substrate, a liquid containing a compound to be a light emitting element In this case, for example, a liquid containing a conductive metal may be discharged from a droplet discharge head provided in each device. Moreover, let the droplet discharge head be a dispenser,
In the case of use for the discharge to a substrate that becomes a microarray of biomolecules, DNA (Deoxyr
A liquid containing a probe such as ibo Nucleic Acids: deoxyribonucleic acid) or other nucleic acids (for example, Ribo Nucleic Acid: ribonucleic acid, Peptide Nucleic Acids: peptide nucleic acid) may be discharged. In addition, it can also be used for discharging dyes such as cloth.

The flow path substrate and the manufacturing method thereof according to the present invention are not applied only to those relating to the droplet discharge head, but can also be applied to microfabricated elements formed by other MEMS and the manufacture thereof.

FIG. 3 is a diagram illustrating a state where the droplet discharge head according to Embodiment 1 is disassembled. 2 is a longitudinal sectional view showing a cross-sectional configuration of a droplet discharge head according to Embodiment 1. FIG. FIG. 6 is a longitudinal sectional view (No. 1) showing the manufacturing process of the flow path substrate according to the first embodiment. FIG. 6 is a longitudinal sectional view (No. 2) showing the manufacturing process of the flow path substrate according to the first embodiment. It is a figure showing the example of patterning of the part 113 used as the 2nd recessed part 13a. It is the figure which showed the conditions of wet thermal oxidation by the relationship of temperature, time, and thickness. 6 is a diagram illustrating a state in which a droplet discharge head according to Embodiment 2 is disassembled. FIG. 6 is a longitudinal sectional view showing a sectional configuration of a droplet discharge head according to Embodiment 2. FIG. 1 is an external view of a droplet discharge device using a droplet discharge head according to the present invention. It is a figure showing an example of the main structural means of a droplet discharge apparatus.

Explanation of symbols

10 channel substrate, 11 nozzle, 11a first nozzle, 11b second nozzle, 11c
3rd nozzle, 12 cavity, 12a 1st recessed part, 13 reservoir, 13a 2nd recessed part, 14 orifice, 15 liquid protective film, 20 diaphragm substrate, 21 diaphragm, 22
Piezoelectric element, 24 upper electrode film, 25 lower electrode film, 26 liquid supply hole, 27 liquid protective film, 2
8 Insulating film, 30 electrode substrate, 31 electrode recess, 32 individual electrode, 33 sealing material, 34
Liquid supply hole, 100 silicon substrate, 101 resist, 102 thermal oxide film, 111a
A portion that becomes the first nozzle 11a, 111b A portion that becomes the second nozzle 11b, 111c A portion that becomes the third nozzle 11c, 112 A portion that becomes the first recess 12a, 113 A portion that becomes the second recess 13a, 113a A patterning portion, 114 part which becomes the orifice 14, 1
15 dummy pattern, 200 printer, 201 drum, 202 droplet discharge head,
203 Paper pressure roller, 204 Feed screw, 205 Belt, 206 Motor, 207
Print control means, 210 print paper.

Claims (8)

A flow path substrate manufacturing method in which a plurality of nozzles, a first recess serving as a plurality of cavities communicating with each nozzle, and a second recess serving as a reservoir communicating with the plurality of cavities are formed on one silicon substrate. Because
Forming a resist on at least one surface of the silicon substrate, and etching and patterning the resist of the plurality of nozzles, the plurality of first recesses, and the second recesses; and
Forming the plurality of nozzles and the plurality of first recesses by anisotropic dry etching; and
Forming a dummy pattern in a portion that becomes the second recess, and oxidizing the dummy pattern;
And removing the oxidized dummy pattern by wet etching to form the second recess. The plurality of nozzles are formed to have a plurality of stages in which the hole diameter decreases toward the direction in which the liquid is discharged,
2. The flow according to claim 1, wherein the dummy pattern in the portion to become the second recess is formed by the same process as anisotropic dry etching for forming at least one stage of the plurality of stages of nozzles. A method for manufacturing a road substrate. 3. The anisotropic dry etching is performed by RIE.
The manufacturing method of the flow-path board | substrate of description. The method for manufacturing a flow path substrate according to claim 1, wherein the anisotropic dry etching is performed by ICP discharge. A flow path substrate manufactured by the flow path substrate manufacturing method according to any one of claims 1 to 4,
A method of manufacturing a droplet discharge head, further comprising a step of bonding one or a plurality of substrates serving as an actuator for pressurizing the liquid. The diaphragm substrate having a plurality of diaphragms for pressurizing the liquid and a plurality of piezoelectric elements for displacing each of the plurality of diaphragms is joined to the flow path substrate. 6. A method of manufacturing a droplet discharge head according to 5. A diaphragm substrate having a plurality of diaphragms for pressurizing the liquid;
An electrode substrate having a plurality of fixed electrodes facing each of the plurality of diaphragms and generating an electrostatic force between the diaphragms to displace the diaphragms;
The method of manufacturing a droplet discharge head according to claim 5, wherein the droplet discharge head is bonded to the flow path substrate. A method for manufacturing a droplet discharge device, wherein the droplet discharge device is manufactured by applying the method for manufacturing a droplet discharge head according to claim 5.

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