JP2008254391A - Electrostatic actuator, electrostatic drive device, liquid-droplet discharge head, and manufacturing method for liquid-droplet discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an electrostatic-actuator manufacturing method or the like that makes the precise depth (a gap length) of a recess measurable. <P>SOLUTION: The electrostatic-actuator manufacturing method is configured to perform a step for forming an etching mask 51 on a glass substrate 50, a step for forming each opening part to form each electrode recessed part 11 and a dummy-pattern recessed part 14 by etching the etching mask 51, a step for forming each electrode recessed part 11 and the dummy-pattern recessed part 14 at each part corresponding to each opening part by etching, a step for further expanding each opening part to form each electrode recessed part 11 and the dummy-pattern recessed part 14, a step for forming each stepped recessed part at each part corresponding to each expanded opening part by etching, a step for forming each recessed part with a desired number of steps by repeating the recessed-part forming step once or several times, a step for forming a film as fixed electrodes, and a step for measuring a depth of the dummy-pattern recessed part 14 by a contact type level-difference meter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

According to the present invention, in the microfabricated element, the movable part is displaced by the applied force, and the operation (drive)
The present invention relates to an electrostatic actuator such as a droplet discharge head that performs the above, an electrostatic device such as a droplet discharge apparatus using the actuator, and a method for manufacturing the same.

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 droplet ejection heads (inkjet heads) used in recording (printing) devices such as droplet ejection printers, micropumps, and variable wavelength light. There are electrostatic actuators and pressure sensors used for filters and motors.

Here, a droplet discharge head using 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. The droplet discharge method is, for example, a method in which a droplet discharge head having a plurality of nozzles is moved relative to an object (such as paper) and the droplets discharged from the droplet discharge head are attached to a predetermined position of the object. Printing and so on. This method uses liquid crystal (Liquid Cryst
al) Electroluminescent (Electr) such as color filters and organic compounds when manufacturing display devices
The display panel (OLED) using the (oLuminescence) element, DNA, protein, and other biomolecule microarrays are also used for manufacturing.

The droplet discharge head is provided with a discharge chamber for storing liquid in a part of the flow path, and at least one wall of the discharge chamber (here, referred to as a bottom wall, hereinafter referred to as a diaphragm). There is a head that uses a method in which the pressure in the discharge chamber is increased by changing the shape by bending (driving) the nozzle and discharging droplets from the communicating nozzle. As a force for displacing and bending the diaphragm, for example, the diaphragm is a movable electrode, and the other electrode facing the diaphragm at a distance (
A voltage (hereinafter referred to as drive voltage) is applied to the fixed electrode), and electrostatic force (particularly electrostatic attractive force) generated by the voltage is used. Since it works by driving using electrostatic force, it becomes an electrostatic actuator.

In the case of a droplet discharge head, a diaphragm serving as a movable electrode is opposed to a fixed electrode and displaced, so that a concave portion is formed on one substrate and the fixed electrode is provided on the bottom (bottom wall) of the diaphragm. It is laminated and bonded to the formed substrate. Here, the space (gap) for the diaphragm to bend is called a gap, and the width is called the gap length.

For example, with respect to a droplet discharge head, in recent years, high-definition printing or the like is required, and the density of nozzles is increasing. Accordingly, the widths of the diaphragm and the fixed electrode corresponding to each nozzle constituting the electrostatic actuator are becoming narrower. Here, when the width of the diaphragm is narrowed, the excluded volume (diaphragm area × opposite distance between electrodes (gap length)) is reduced, and the amount of liquid droplets discharged from the nozzle is also reduced. In order to increase the excluded volume while maintaining high density, the gap length may be increased. However, in order to obtain a necessary electrostatic force, the drive voltage must be increased.

For this reason, the drive voltage is lowered by making the groove in which the elongated rectangular electrode is formed stepwise in the width (short side) direction and setting the gap length between the fixed electrode and the diaphragm to 2 or more. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2000-318155 (FIGS. 2, 4, and 5)

Here, for example, the gap length greatly affects the driving of the electrostatic actuator, for example, the droplet discharge head greatly affects the discharge performance. For this reason, it is very important to form the recess (gap length) at the designed depth (length). In particular, in the case where the stepped recesses (fixed electrodes) as described above are provided, there are a plurality of portions having different gap lengths, and accordingly, accuracy is required in forming each step of the recesses.

Such accuracy is also required when measuring the depth of the recess. Since the measurement of the depth of the recess requires nanometer-order accuracy, it is desirable to perform the measurement using a device such as a stylus type step gauge.

However, as described above, when the density is increased, the width of the recessed portion to be formed is reduced. For this reason, the recessed portion opening portion becomes small, and it is difficult to measure the depth of the recessed portion by inserting a measuring needle into the recessed portion. If measurement is not successful, the yield may be reduced. In some cases, the apparatus cannot automatically perform measurement. In this case, manual measurement must be performed, resulting in an increase in man-hours and a significant increase in cost.

In order to solve such problems, the present invention provides an electrostatic actuator, a droplet discharge head, a droplet discharge device, and an electrostatic drive device that can measure the depth (gap length) of the recess with high accuracy. It aims at obtaining a manufacturing method.

In the method for manufacturing an electrostatic actuator according to the present invention, a step of forming an etching mask on a substrate to be an electrode substrate, and etching the etching mask to form a concave portion for forming a fixed electrode and a concave portion for inspection measurement. Forming an opening for etching, etching, forming a recess for forming a fixed electrode and a dummy pattern recess in a portion corresponding to the opening of the substrate, etching the etching mask, and opening the opening By widening, an opening wider than the opening is formed, and for the opening for forming the dummy pattern recess, a process of forming a wider opening and etching is performed to cope with the widened opening. The step of forming a stepped recess in the portion to be formed, the step of forming a wide opening and the step of forming a stepped recess are repeated one or more times. The step of forming a desired number of recesses in the substrate, the step of forming a conductive film to be a fixed electrode in the recesses for forming the fixed electrodes and the dummy pattern recesses, and the depth of the dummy pattern recesses in a contact type The electrode substrate is formed by performing a step of measuring with a step gauge.
According to the present invention, since the concave portion for forming the fixed electrode is formed at the same time as the concave portion for forming the dummy pattern, the dummy pattern concave portion is measured instead of the concave portion for forming the fixed electrode. Thus, the depth of the concave portion for forming the fixed electrode can be inspected.

In the method for manufacturing an electrostatic actuator according to the present invention, one side of the concave portion of the dummy pattern is formed wider than the short side of the concave portion for forming the fixed electrode.
According to the present invention, since each side of the concave portion of the dummy pattern is formed wider than the short side of the concave portion for forming the fixed electrode, an electrode such as a stylus step meter can be used in a wide area. The depth of the recess can be inspected more accurately.

Moreover, the manufacturing method of the electrostatic actuator which concerns on this invention forms the rectangular-shaped dummy pattern recessed part which has a width | variety of 100 micrometers or more on one side.
According to the present invention, since a rectangular dummy pattern recess having a width of 100 μm or more is formed on one side, the depth of the dummy pattern recess is automatically measured using a device such as a stylus type step meter, The inspection of the concave portion for forming the fixed electrode can be performed more accurately.

Moreover, the manufacturing method of the electrostatic actuator which concerns on this invention measures the depth in the part of the formed dummy pattern recessed part with a contact-type level difference meter before forming an electrically conductive film.
According to the present invention, the depth at the concave portion of the dummy pattern is measured by the contact type step meter before forming the conductive film. Therefore, the concave portion for forming the fixed electrode can be formed even before forming the conductive film. Depth inspection can be performed more accurately.

In addition, a method for manufacturing a droplet discharge head according to the present invention is a method for manufacturing a droplet discharge head by applying the above-described method for manufacturing an electrostatic actuator.
According to the present invention, since the electrostatic actuator manufacturing method described above is applied, the inspection can be accurately performed, and the droplet discharge head can be manufactured in a form in which the defective electrode substrate is removed in advance. Therefore, the yield of the finally manufactured droplet discharge head can be improved. In addition, a predetermined discharge performance can be obtained for the manufactured droplet discharge head.

In addition, 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.
According to the present invention, since the above-described method for manufacturing a droplet discharge head is applied, a droplet discharge apparatus that can perform high-definition and high-quality printing and the like can be manufactured.

Moreover, the manufacturing method of the electrostatic drive device which concerns on this invention applies a manufacturing method of said electrostatic actuator, and manufactures a device.
According to the present invention, since the method for manufacturing an electrostatic actuator described above is applied, an electrostatic drive device having high operating performance can be manufactured.

Embodiment 1 FIG.
FIG. 1 is an exploded view of a droplet discharge head according to Embodiment 1 of the present invention. FIG. 1 shows a part of the droplet discharge head. In this embodiment, for example, a face eject type droplet discharge head will be described as a representative of a device using an electrostatic actuator driven by an electrostatic method. (In addition, in order to make the components shown and easy to see, the relationship between the sizes of the components in the following drawings including FIG. 1 may be different from the actual one. Explained with the side down).

As shown in FIG. 1, the droplet discharge head according to the present embodiment is configured by laminating three substrates of an electrode substrate 10, a cavity substrate 20, and a nozzle substrate 30 in order from the bottom. Here, in the present embodiment, the electrode substrate 10 and the cavity substrate 20 are bonded by anodic bonding. Also,
The cavity substrate 20 and the nozzle substrate 30 are bonded using an adhesive such as an epoxy resin.

The electrode substrate 10 is mainly made of a substrate such as a borosilicate heat-resistant hard glass having a thickness of about 1 mm. Although a glass substrate is used in this embodiment mode, for example, single crystal silicon can be used as a substrate. On the surface of the electrode substrate 10, a discharge chamber 21 of a cavity substrate 20 to be described later is provided.
Accordingly, a plurality of electrode recesses 11 are formed. Here, in the present embodiment, the portion corresponding to the discharge chamber 21 (the vibration plate 22) of the electrode recess 11 is formed in a staircase (step) shape in which the central portion is deepest particularly in the long side direction. There are steps. Although it may be in the short side direction, the long side direction is easier to process and an efficient effect can be expected. Here, it is assumed that there are three steps. In the portion where the individual electrode 12A is formed, the depth of the shallowest end portions is, for example, 150 nm here. The next shallowest part is, for example, 17
The depth is set to 0 nm, and the deepest central portion is set to 190 nm, for example. Here, in manufacturing, in order to ensure that an electrode material can be formed inside the electrode recess 11, the electrode recess 11 is formed wider than the actually formed individual electrode 12 </ b> A or the like.

Further, inside the electrode recess 11 (particularly the bottom), each discharge chamber 21 (
An individual electrode 12A serving as a fixed electrode is provided so as to face the diaphragm 22), and a lead portion 12B and a terminal portion 12C are provided integrally with the individual electrode 12A (hereinafter, it is necessary to particularly distinguish them). Otherwise, these are combined to form the electrode portion 12). The electrode part 12 is made of about 0.07 μm of ITO (Indium Tin Oxide) by sputtering, for example.
It is formed by depositing the film inside the electrode recess 11 with a thickness of (70 nm). Here, in the present embodiment, since the thickness of the electrode portion 12 is uniform with respect to the electrode recess 11, the individual electrode 12 </ b> A has the same level difference as the electrode recess 11. . Between the diaphragm 22 and the individual electrode 12 </ b> A, a gap in which the diaphragm 22 can be bent (displaced) is formed by the electrode recess 11. Since the individual electrode 12A has a stepped shape, the gap length varies depending on the position. Here, since there are three steps as described above, the individual electrode 12A
Of the shallowest end portions are 80 nm (hereinafter referred to as G1), and the next shallowest gap length is 100 nm (hereinafter referred to as G2).
And the deepest central portion has a gap length of 120 nm (hereinafter, this gap length is referred to as G3). In addition, the electrode substrate 10 is provided with a through-hole serving as a liquid supply port 13 serving as a flow path for taking in liquid supplied from an external tank (not shown).

In the embodiment, the dummy pattern recess 14 is provided on the electrode substrate 10 so that the gap length (depth of the electrode recess 11) can be measured more accurately. Since the dummy pattern recess 14 is formed in the same process as the electrode recess 11, a step having the same depth as the electrode recess 11 is formed. Here, in order to cope with the measurement by a device such as a stylus type step meter, the dummy pattern concave portion 14 has a long length, for example, the larger the area of the opening portion, the better. Since the number of manufactured electrode substrates 10 may be reduced, it is desirable to make the size appropriate. For example, considering that the width (short side) direction of the electrode recess 11 is currently about 35 μm, it is considered that one side of the dummy pattern recess 14 needs to have a length of at least about 40 μm. Moreover, in order to measure the gap length (the depth of the concave portion) with high accuracy by automatic measurement using a device such as a stylus step meter, it is preferable that one side is about 100 μm or more, and one side is 150 μm or more. It is considered that the dummy pattern concave portion 14 is formed so as to be more preferable. Considering the above, the length of the dummy pattern recess 14 is determined in accordance with the number of manufacturing per glass substrate.

The cavity substrate 20 is mainly composed of a silicon single crystal substrate (hereinafter referred to as a silicon substrate) whose surface has a (100) plane orientation, a (110) plane orientation, or the like. Cavity substrate 2
In 0, a recess (a bottom wall is a diaphragm 22 serving as a movable electrode) serving as a discharge chamber 21 for temporarily storing a liquid to be discharged is formed. In the present embodiment, the diaphragm 22 is also formed in a stepped shape such that the central portion is deepest, particularly in the long side direction. A TEOS film (here, Tetraethyl orthosi) for electrically insulating the diaphragm 22 and the individual electrode 12A is formed on the lower surface of the cavity substrate 20 (the surface facing the electrode substrate 10).
licate Tetraethoxysilane: SiO made using tetraethoxysilane (ethyl silicate)
_The insulating film 23, which is _two films), is formed by plasma CVD (Chemical Vapor Deposition: TEO)
(Also referred to as S-pCVD) is used to form a film of 0.1 μm (100 nm). Here, the insulating film 23 is a TEOS film. For example, Al2O3 (aluminum oxide (alumina)).
) May be used. In addition, a recess is formed which becomes a reservoir (common liquid chamber) 24 for supplying a liquid to each discharge chamber 21. Further, the individual electrode 1 is applied from the external oscillation circuit to the substrate (diaphragm 22).
A common electrode terminal 27 serving as a terminal for supplying a charge having a polarity opposite to that of 2A is provided.

The nozzle substrate 30 is also mainly made of a silicon substrate, for example. Nozzle substrate 30
A plurality of nozzle holes 31 are formed. Each nozzle hole 31 discharges liquid pressurized by driving (displacement) of the diaphragm 22 to the outside as droplets. If the nozzle holes 31 are formed in a plurality of stages, it is expected to improve straightness when ejecting liquid droplets.
Are formed in two stages. In the present embodiment, a diaphragm 32 is further provided for buffering the pressure applied in the direction of the reservoir 24 when the diaphragm 22 is displaced. In addition, an orifice 33 for communicating the discharge chamber 21 and the reservoir 24 is provided on the lower surface.

FIG. 2 is a cross-sectional view of the droplet discharge head. The sealing material 25 is provided at the electrode outlet 26 so as to block and seal the gap from the outside space so that foreign matter, moisture (water vapor) or the like does not enter the gap. The electrode outlet 26 is provided to expose the terminal portion 12C to the outside. The oscillation circuit 41 is electrically connected to the terminal portion 12C exposed from the common electrode terminal 27 and the electrode outlet 25 through a wire 42 such as a wire or FPC (Flexible Print Circuit), and the individual electrode 12A and the cavity substrate 20 are connected. Supply and stop of electric charge (electric power) to (vibration plate 22) are controlled. The oscillation circuit 41 oscillates at, for example, 24 kHz, supplies charges to the individual electrodes 12A, and applies pulse voltages of, for example, 0V and 30V. When the oscillation circuit 41 is driven to oscillate to supply charges to the individual electrodes 12A to be positively charged and the diaphragm 22 is relatively negatively charged, the diaphragm 22 is attracted to the individual electrodes 12A by electrostatic force. Bend. As a result, the volume of the discharge chamber 21 is expanded. When the supply of electric charges is stopped, the diaphragm 22 returns to its original shape (restores), but the volume of the discharge chamber 21 at that time also returns to its original value, and a differential droplet is discharged by the pressure.
Recording such as printing is performed when the droplets land on a recording sheet to be recorded, for example.

FIG. 3 is a diagram illustrating an example of a manufacturing process of the electrode substrate 10. Based on FIG. 3, a manufacturing procedure of the electrode substrate 10 according to the present embodiment will be described. Here, in the manufacture of the droplet discharge head, a plurality of substrates such as the electrode substrate 10 are actually manufactured at the same time in units of wafers. Although the ejection head is manufactured, in the drawings showing the following steps, a cross section when a part of one droplet ejection head is cut in the long side direction is shown.
3 shows the side on which the electrode recess 11 is formed, and the right side shows the side on which the dummy pattern recess 14 is formed. Here, theoretically, it is only necessary to form one dummy pattern concave portion 14 for one wafer, but here, each electrode substrate 10 can be measured with high accuracy in a portion close to each electrode substrate 10. It is assumed that one dummy pattern recess 14 is formed.

First, for example, a glass substrate 50 having a thickness of 2 to 3 mm is ground (grinded) by mechanical grinding, etching or the like until the thickness of the substrate 3a becomes about 1 mm, for example. Then, for example, the glass substrate 50 is etched by 10 to 20 μm to remove the work-affected layer (FIG. 3A
)). For removing the work-affected layer, for example, dry etching with SF ₆ or the like, spin etching with hydrofluoric acid aqueous solution, or the like may be performed. When dry etching is performed, the work-affected layer formed on one surface of the glass substrate 50 can be efficiently removed, and protection of the opposite surface is not required. Further, when performing spin etching (wet etching), a small amount of etching solution is required, and a new etching solution is always supplied, so that stable etching can be performed.

A film to be an etching mask 51 made of chromium (Cr) is formed on the entire surface of the glass substrate 50 by, for example, sputtering. Then, a resist (not shown) is patterned on the surface of the etching mask 51 by photolithography so as to correspond to the shape (rectangular shape) of the central portion (portion of gap length G3) and the shape of a part of the dummy pattern concave portion 14. Further, wet etching or the like is performed to expose the glass substrate 50 (FIG. 3B). afterwards,
For example, the glass substrate 50 is wet-etched with a hydrofluoric acid aqueous solution such as a BHF (buffered hydrofluoric acid; hydrofluoric acid: ammonium fluoride = 1: 6) aqueous solution to form the recess 52 (FIG. 3C
)). The etching amount (etching depth) at this time is about 20 nm (a step between the gap length G3 portion and the gap length G2 portion).

Then, by photolithography, patterning is performed in accordance with the shape of the gap length G2 portion, wet etching or the like is performed, and the glass substrate 50 is made to correspond to the shape of the gap length G2 portion and further part of the dummy pattern recesses 14. Are also exposed (FIG. 3D). Then, for example, the glass substrate 50 is wet-etched with a hydrofluoric acid aqueous solution to form the recess 53 (FIG. 3E). The etching amount (etching depth) at this time is about 20 nm (step difference between the gap length G2 portion and the gap length G1 portion). As a result, the recess 53 becomes 2
The depth of the central part by etching becomes 40 nm.

Further, wet etching or the like is performed by patterning in accordance with the shape of the gap length G1 (including the portion where the lead portion 12B and the terminal portion 12C are formed) and the shape of a part of the dummy pattern recess 14 by photolithography. To expose the glass substrate 50 at the gap length G1 (FIG. 3F). For example, a glass substrate 5 with a hydrofluoric acid aqueous solution.
0 is wet-etched, and finally the electrode recess 11 is formed (FIG. 3G). Also,
For example, an air opening hole (not shown) for making the pressure in the gap the same as the external pressure may be formed in a later step. The etching amount (etching depth) at this time is 150 nm (same as the gap length G1). Here, for example, four or more recesses 1 for electrodes
1 and the dummy pattern recess 14 are formed, the above steps are repeated.

Thereafter, an ITO film 54 having conductivity is formed by sputtering, for example, on the entire surface of the glass substrate 50 on which the electrode recess 11 is formed (FIG. 3H). At this time, the ITO film 54 is formed to be thicker than any step included in the recess 11 for electrodes formed in a staircase shape to prevent disconnection. Then, a resist (not shown) is patterned by photolithography, and the ITO film 54 is etched after protecting the portion left as the electrode portion 12.
Here, the ITO film 54 is also protected at the dummy pattern recess 14 to leave the ITO film 54. For example, as described later, this is provided to prevent the silicon substrate and the glass substrate from being bonded when anodic bonding to the silicon substrate is performed. Another reason is that the inspection can be performed under the same conditions as the portion where the electrode is formed when the gap length is inspected. Further, a through hole that becomes the liquid supply port 13 is formed by a sandblasting method or a cutting process (FIG. 3 (i)). The electrode substrate 10 is manufactured through the above steps.

For the electrode substrate 10 formed as described above, automatic measurement is performed using an apparatus such as a stylus type step gauge using the dummy pattern concave portion 14. Since the ITO film 54 having the same thickness as the electrode part 12 is formed inside the dummy pattern concave part 14, the individual electrode 12A (electrode part 1
The depth (gap length) of the part 2) can be measured in the dummy pattern recess 14 part. Here, the depth of the electrode substrate 10 that was finally produced was measured. However, for example, the measurement may be performed before the ITO film 54 is formed.

FIG. 4 is a diagram showing a manufacturing process of the droplet discharge head. One side of the silicon substrate 60 (becomes the bonding surface side with the electrode substrate 10) is mirror-polished to produce, for example, a 220 μm thick substrate (becomes the cavity substrate 20). Next, the surface of the silicon substrate 60 on which the boron doped layer 61 is formed is opposed to a solid diffusion source mainly composed of B ₂ O ₃ , and is placed in a vertical furnace to diffuse boron into the silicon substrate 60. Boron doped layer 61 with a concentration (about 5 × 10 ¹⁹ atoms / cm ³ )
Form. Then, on the surface on which the boron doped layer 61 is formed, the plasma CVD method is used, the processing temperature during film formation is 360 ° C., the high frequency output is 250 W, and the pressure is 66.7 Pa (0.5 Torr).
r), the gas flow rate is TEOS flow rate 100 cm ³ / min (100 sccm), oxygen flow rate 10
The insulating film 23 is formed to a thickness of 0.1 μm under the condition of 00 cm ³ / min (1000 sccm) (FIG. 4A).

After the silicon substrate 60 and the electrode substrate 10 are heated to 360 ° C., a negative electrode is connected to the electrode substrate 10 and a positive electrode is connected to the silicon substrate 60, and a voltage of 800 V is applied to perform anodic bonding. At this time, at the interface between the silicon substrate 60 and the electrode substrate 10, the glass may be electrochemically decomposed to generate oxygen as a gas. Gas (gas) adsorbed on the surface by heating
May occur. However, since these gases escape from the air opening holes, the gap does not become positive pressure. Then, the surface of the silicon substrate 60 is ground until the thickness of the silicon substrate 60 becomes about 60 μm in the substrate after the anodic bonding (hereinafter referred to as a bonded substrate). Thereafter, in order to remove the work-affected layer, the silicon substrate 60 is wet-etched by about 10 μm with a potassium hydroxide solution having a concentration of 32 w%. As a result, the thickness of the silicon substrate 60 is reduced to about 50 μm (FIG. 4B).

In this grinding step and work-affected layer removal step, the air release hole is closed and protected using a single-sided protective jig, tape, or the like so that liquid does not enter the gap from the air release hole. Here, in the next step, since the substrate is heated again, gas may be generated in the gap. Therefore, in this step, the air opening hole is not completely blocked, and the gap (electrode recess 11) can be communicated with the outside again.

For example, here, when the diaphragm 22 (silicon substrate 60) is viewed through the transparent glass substrate 10 and ITO film in the visible light region, the color changes depending on the gap length due to light interference and the like. To do. Thereby, the gap length can be inspected. In the present embodiment, this inspection is performed in a portion where the dummy pattern recess 14 is formed. Since the dummy pattern concavity 14 is formed larger than the electrode concavity 11, it is easy to catch a change in color and facilitate inspection. Therefore, it is possible to perform a highly accurate inspection more easily.

Next, a TEOS etching mask (hereinafter referred to as a TEOS etching mask) 61 is formed on the wet-etched surface by plasma CVD. As film formation conditions, for example, the processing temperature during film formation is 360 ° C., the high frequency output is 700 W, and the pressure is 33.
3 Pa (0.25 Torr), gas flow rate is TEOS flow rate 100 cm ³ / min (100 s
ccm) and an oxygen flow rate of 1000 cm ³ / min (1000 sccm), about 1.0 μm
A film is formed (FIG. 4C). Since film formation using TEOS can be performed at a relatively low temperature,
This is convenient in that the heating of the substrate can be suppressed as much as possible. After forming the TEOS etching mask 61, for example, an epoxy adhesive or the like is poured into the air opening hole to seal the air opening hole.
As a result, the gap is hermetically sealed, so that liquid or the like does not enter from the air opening hole in the subsequent steps. By sealing the air opening hole after forming the TEOS etching mask 61, gas expansion in the gap due to heating during film formation can be prevented.

Then, the TEOS etching mask 61 in the portion that becomes the discharge chamber 22 and the electrode outlet 25 is formed.
In order to etch, resist patterning is performed. Then, using a hydrofluoric acid aqueous solution, T
The portion is etched until the EOS etching mask 61 disappears, and the TEOS etching mask 61 is patterned to expose the silicon substrate. Then, after etching, the resist is peeled off. Here, with respect to the portion to be the electrode extraction port 25, for example, even if silicon is not exposed for all, for example, a portion that becomes a boundary between the electrode extraction port 25 and the cavity substrate 20 is exposed, and the remaining portion is left in an island shape. The silicon may be prevented from cracking.

Further, resist patterning is performed in order to etch the TEOS etching mask 61 in the portion that becomes the reservoir 24. Then, the TEOS etching mask 61 in those portions is etched by about 0.7 μm with a hydrofluoric acid aqueous solution and patterned. As a result, the thickness of the TEOS etching mask 61 remaining in the portion that becomes the reservoir 24 becomes about 0.3 μm, but the silicon substrate is not exposed. Here, the thickness of the TEOS etching mask 43 to be left is about 0.3 μm, but this thickness needs to be adjusted according to the desired depth of the reservoir 24. Then, after the etching, the resist is peeled off (FIG. 4D).

Next, the bonded substrate is immersed in a 35 wt% potassium hydroxide aqueous solution, and the thickness of the portion where the silicon serving as the discharge chamber 22 and the portion serving as the electrode outlet 26 is exposed is about 10 μm.
Wet etching is performed until m is reached. Thereafter, in order to remove the TEOS etching mask 61 in the portion to be the reservoir 24, the bonded substrate is immersed in a hydrofluoric acid aqueous solution and etched to be removed. Further, the bonded substrate is immersed in a 3 wt% potassium hydroxide aqueous solution, and etching is continued until it is determined that the etching stop is sufficiently effective in the boron doped layer. As described above, by performing etching using the two types of potassium hydroxide aqueous solutions having different concentrations, the surface roughness of the diaphragm 22 to be formed is suppressed, and the thickness accuracy is 0.80 ± 0.05 μm or less. be able to. As a result, the discharge performance of the droplet discharge head can be stabilized. And the diaphragm 2 formed in a step shape (three steps) in this process
2 appears (FIG. 4E).

When the wet etching is finished, the bonded substrate is immersed in a hydrofluoric acid aqueous solution, and the TEOS etching mask 61 on the surface of the silicon substrate 60 is peeled off. Then, in order to remove silicon in a portion that becomes the electrode extraction port 25 of the silicon substrate 60, a silicon mask having an opening in the portion that becomes the electrode extraction port 25 is attached to the surface of the bonded substrate on the silicon substrate 60 side. And
For example, RF power 200 W, pressure 40 Pa (0.3 Torr), CF ₄ flow rate 30 cm ³
RIE dry etching (anisotropic dry etching) is performed for 2 hours under the condition of / min (30 sccm), and plasma is applied only to a portion that becomes the electrode extraction port 25 to open. Opening also opens the gap to the atmosphere. Here, the electrode outlet 2
The portion of silicon that becomes 5 may be removed.

Then, a sealing material 25 made of, for example, epoxy resin is poured along the end of the electrode outlet 26 (the opening portion of the gap formed between the cavity substrate 20 and the recess of the electrode substrate 10) to seal the gap. Stop. In addition, a mask having an opening in a portion to be the common electrode terminal 27 is
It is attached to the surface of the bonding substrate on the silicon substrate 60 side. Then, for example, sputtering is performed using platinum (Pt) as a target to form the common electrode terminal 27. The liquid supply port 1
3 is formed in the silicon substrate 60 to allow the reservoir 3 to communicate with the reservoir 24. Here, in order to protect the cavity substrate 20 from the liquid flowing through the flow path, a liquid protective film (not shown) such as silicon oxide may be further formed. Thereby, the processing performed on the bonded substrate is completed (FIG. 4F).

By forming the nozzle hole 31, the diaphragm 32, and the orifice 33 in advance, the manufactured nozzle substrate 30 is bonded from the cavity substrate 20 side of the bonded substrate with, for example, an epoxy adhesive. Then, dicing is performed to cut into individual droplet discharge heads, thereby completing the droplet discharge heads (FIG. 4G). Here, the dummy pattern concave portion 14 is left in the finally manufactured droplet discharge head, but it may be cut together with dicing.

As described above, in the electrostatic actuator (droplet discharge head) according to the first embodiment, the electrode recess 11 is simultaneously formed, and at the same time, the dummy pattern recess 14 having a long side in the short side direction of the electrode recess 11 is simultaneously formed. Since the depth of the electrode recess 11 is inspected by automatically measuring the portion of the dummy pattern recess 14 with a device such as a stylus type step gauge, the gap length formed (by wet etching) The measurement of the depth of the formed recess) can be performed more accurately. In addition, even after the silicon substrate serving as the cavity substrate 20 is bonded, the change in the interference light based on the length of the gap length in a large area can be captured better, and the width of the gap length can be accurately measured. Accordingly, the yield of the finally manufactured droplet discharge head can be improved without using the electrode substrate 10 in which the predetermined gap length is not formed in advance for manufacturing the subsequent droplet discharge head. In addition, a predetermined discharge performance can be obtained for the manufactured droplet discharge head. Here, for convenience of manufacturing, the individual electrodes 12A and the like are stepped and have a stepped structure, but may be formed to have a slope or the like, for example.

Embodiment 2. FIG.
In the above-described embodiment, the measurement was performed on the electrode recess 11 and the dummy pattern recess 14 configured in three stages. However, for example, a single-stage recess can also be applied. Further, in the above-described embodiment, the shape of the dummy pattern concave portion 14 is rectangular according to the shape of the electrode concave portion 11, but the depth can be measured by a device such as a stylus step meter, A predetermined number of electrode substrates 10
As long as it can be manufactured, the shape is not limited.

Embodiment 3 FIG.
FIG. 5 is an external view of a droplet discharge apparatus using the droplet discharge head manufactured in the above embodiment. FIG. 6 is a diagram illustrating an example of main components of the droplet discharge device. 5 and 6 is intended for printing by a droplet discharge method (inkjet method). Further, it is a so-called serial type device. In FIG. 6, a drum 101 that supports a printing paper 100 that is a substrate to be printed and a droplet discharge head 102 that discharges ink to the printing paper 100 and performs recording are mainly configured. Although not shown, there is an ink supply means for supplying ink to the droplet discharge head 102. The print paper 110 is held by being pressed against the drum 101 by a paper press roller 103 provided parallel to the axial direction of the drum 101. A feed screw 104 is provided parallel to the axial direction of the drum 101, and the droplet discharge head 102 is held. As the feed screw 104 rotates, the droplet discharge head 102 is moved to the drum 1.
It moves in the axial direction of 01.

On the other hand, the drum 101 is rotationally driven by a motor 106 via a belt 105 or the like.
The print control means 107 also feeds the feed screw 104 based on the print data and the control signal.
The motor 106 is driven, and although not shown here, the oscillation circuit 4 is driven to vibrate the diaphragm 4, and printing is performed on the print paper 110 while being controlled.

Here, the liquid is ejected onto the print paper 110 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.

Embodiment 4 FIG.
FIG. 7 is a diagram showing an optical switch using an electrostatic actuator using the present invention. In the above-described embodiment, the liquid droplet ejection head and the liquid droplet ejection apparatus using the liquid droplet ejection head have been described as examples. However, the present invention is not limited thereto, and other microfabricated elements (devices) and apparatuses. It can also be applied to.

For example, the optical switch of FIG. 7 used in optical communication, optical calculation, optical storage device, optical printer, video display device, etc. changes the tilt angle of the micro mirror 200 and reflects light in the selected direction, It plays the role of using a switching element based on light. In order to control the tilt angle of the micromirror 200, a support shaft 210 that supports the micromirror 200 is provided.
For example, a movable electrode 220 which is a driven portion is provided in a line-symmetric position with respect to the electrode substrate 24.
The fixed electrode 230, which is a driving unit, formed at 0 is arranged to face the gap at a predetermined interval (gap). Then, the micromirror 20 is rotated by rotating the support shaft 210 using the electrostatic force.
Control the tilt angle of zero. At this time, as in the first embodiment, the movable electrode 220 and the fixed electrode 230 are formed in a step shape, so that the movable electrode 220 can be driven with respect to the driving voltage as compared with the conventional case.
, And the inclination angle of the micromirror 200 can be changed to a desired angle. Similarly, the above-mentioned movable electrode and fixed electrode are also applied to other types of microfabricated electrostatic actuators such as motors, sensors, resonator elements such as SAW filters, wavelength tunable optical filters, and other mirror devices. Combinations can be applied. In particular, in the droplet discharge head, both ends of the diaphragm serving as the movable electrode are supported on the long side, but the diaphragm can also be used for an actuator having a structure supporting one end.

2 is an exploded view of a droplet discharge head according to Embodiment 1. FIG. It is sectional drawing of a droplet discharge head. 5 is a diagram illustrating an example of a manufacturing process of the electrode substrate 10. It is a figure which shows the manufacturing process of a droplet discharge head. It is an external view of a droplet discharge device using a droplet discharge head. It is a figure showing an example of the main structural means of a droplet discharge apparatus. It is a figure showing the optical switch using the electrostatic actuator of this invention.

Explanation of symbols

10 electrode substrate, 11 electrode recess, 12 electrode portion, 12A individual electrode, 12B lead portion, 12C terminal portion, 13 liquid supply port, 20 cavity substrate, 21 discharge chamber, 22
Diaphragm, 23 Insulating film, 24 Reservoir, 25 Sealing material, 26 Electrode outlet, 27
Common electrode terminal, 30 nozzle substrate, 31 nozzle hole, 32 diaphragm, 33 orifice, 41 oscillation circuit, 42 wiring, 50 glass substrate, 51 etching mask, 52
, 53 Recess, 54 ITO film, 60 Silicon substrate, 61 TEOS etching mask, 100 Printer, 101 drum, 102 Droplet ejection head, 103 Paper pressure roller, 104 Feed screw, 105 Belt, 106 Motor, 107 Print control means, 1
10 Print paper, 200 Micromirror, 210 Support shaft, 220 Movable electrode, 230
Fixed electrode, 240 electrode substrate.

Claims (7)

Forming an etching mask on a substrate to be an electrode substrate;
Etching the etching mask to form openings for forming concave portions for forming fixed electrodes and dummy pattern concave portions for inspection and measurement;
Etching, forming a concave portion for forming a fixed electrode and the concave portion of the dummy pattern in a portion corresponding to the opening of the substrate;
By etching the etching mask to widen the opening, an opening wider than the opening is formed, and a wider opening is also formed for the opening for forming the dummy pattern recess. Process,
Etching and forming the step-shaped recess in the portion corresponding to the widened opening,
The step of forming the wide opening and the step of forming the stepped recesses one or more times to form a desired number of recesses on the substrate;
Forming a conductive film to be the fixed electrode in the recessed portion for forming the fixed electrode and the recessed portion of the dummy pattern;
And a step of measuring the depth of the concave portion of the dummy pattern with a contact-type step meter to form the electrode substrate. 2. The method of manufacturing an electrostatic actuator according to claim 1, wherein each side of the concave portion of the dummy pattern is formed wider than a short side of the concave portion for forming the fixed electrode. 3. The method for manufacturing an electrostatic actuator according to claim 2, wherein the dummy pattern concave portion having a rectangular shape having a width of 100 [mu] m or more on one side is formed. The method for manufacturing an electrostatic actuator according to any one of claims 1 to 3, wherein a depth of the formed dummy pattern recess is measured by a contact-type step gauge before forming the conductive film. . A method for manufacturing a droplet discharge head, wherein the method for manufacturing an electrostatic actuator according to claim 1 is applied to manufacture a droplet discharge head. 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. A device is manufactured by applying the method for manufacturing an electrostatic actuator according to claim 1.

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