JP2006320121A - Manufacturing method of electrostatic actuator, droplet discharging head, device, and droplet discharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an electrostatic actuator that does not generate cracks and breakage to a silicon substrate during manufacturing, and does not cause a thinned diaphragm and an electrode takeout to be cracked. <P>SOLUTION: The manufacturing method of the electrostatic actuator comprises a process that forms an electrode recess 10a for forming an electrode 11 on a glass substrate 2a, and forms the electrode 11 in the electrode recess 10a; a process that film-forms a getter material 31 in a recess 30 that becomes a getter chamber by forming the recess 30 of the getter chamber, for accommodating the getter material 31 that communicates with the electrode recess 10a and adsorbs gas in the electrode recess 10a on the glass substrate 2a; a process that thins the silicon substrate 1a after cathode-joining the silicon substrate 1a to the glass substrate 2a; and a process that separates the electrode recess 10a and the getter chamber by using sealing material 22, by sealing the electrode recess 10a by using the sealing material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for manufacturing an electrostatic actuator, a method for manufacturing a droplet discharge head, a method for manufacturing a device, and a method for manufacturing a droplet discharge apparatus, and in particular, a static that can prevent the thinned silicon substrate from cracking. The present invention relates to a method for manufacturing an electric actuator, a method for manufacturing a droplet discharge head using the method for manufacturing an electrostatic actuator, a method for manufacturing a device, and a method for manufacturing a droplet discharge apparatus.

In recent years, electrostatic drive type droplet discharge heads have been required to increase the density of nozzles and discharge chambers for discharging droplets in order to pursue high printing performance. In such a droplet discharge head, it is necessary to use, for example, a silicon substrate having a thickness of 200 μm or less in order to prevent so-called crosstalk, and the silicon substrate is cracked or chipped during manufacture, resulting in a high yield. There was a problem that it decreased. Further, it is difficult to increase the diameter of such a thin silicon substrate, and there is a problem that the number of droplet discharge heads that can be taken out from one silicon substrate cannot be increased.

In order to solve such problems, in the conventional inkjet head manufacturing method, after the silicon substrate is anodically bonded to the electrode glass substrate, the silicon substrate is thinned, and a concave portion serving as a discharge chamber is formed on the thinned silicon substrate. Is formed by etching (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-993 (FIGS. 3 and 4)

However, in a conventional method of manufacturing an inkjet head (see, for example, Patent Document 1), a gas such as oxygen is generated when anodically bonding a silicon substrate to an electrode glass substrate, and a gap (electrode) between the silicon substrate and the electrode glass substrate is generated. In the space between the diaphragm and the diaphragm. For this reason, when the silicon substrate is etched to reduce the thickness of the concave portion serving as a discharge chamber, the concave portion serving as a reservoir, and the electrode lead-out portion, the gap is in a pressurized state, and the thinned diaphragm (discharge chamber) ) And the electrode lead-out part may be broken.

The present invention relates to a method for manufacturing an electrostatic actuator and a method for manufacturing the electrostatic actuator in which a silicon substrate is not cracked or chipped during manufacturing, and a thinned diaphragm or electrode extraction portion is not cracked. It is an object of the present invention to provide a manufacturing method of a droplet discharge head having a high yield, a device manufacturing method, and a droplet discharging apparatus manufacturing method.

The method for manufacturing an electrostatic actuator according to the present invention includes a step of forming a recess for an electrode for forming an electrode on a glass substrate, and forming the electrode in the recess for the electrode. A step of forming a recess serving as a getter chamber for accommodating a getter material that adsorbs the gas in the electrode recess and depositing the getter material in the recess serving as the getter chamber; After anodically bonding the silicon substrate, a step of thinning the silicon substrate and a step of separating the electrode recess and the getter chamber with the sealing material by sealing the electrode recess with the sealing material I have it.
A recess serving as a getter chamber communicating with the electrode recess is formed in the glass substrate, and a getter material is formed in the recess so that a gas such as oxygen generated during anodic bonding can be adsorbed to the silicon substrate. It is possible to prevent the thinned portion (vibration plate or the like) from cracking when a recess or the like serving as a discharge chamber is formed. In addition, since the electrode recess and the getter chamber are separated by the sealing material, the gas in the gap between the silicon substrate and the glass substrate is excessively adsorbed when the driving of the electrostatic actuator is repeated, and the diaphragm and It is possible to prevent the electrodes from sticking.
Furthermore, since the silicon substrate is thinned after anodically bonding the silicon substrate to the glass substrate, handling of the silicon substrate is facilitated, and the silicon substrate can be prevented from being cracked or chipped. This also makes it possible to increase the diameter of the silicon substrate, and a number of electrostatic actuator chips can be manufactured from a single silicon substrate, thereby improving productivity.

In the method for manufacturing an electrostatic actuator according to the present invention, the getter chamber is provided for each chip of the electrostatic actuator.
By providing the getter chamber for each chip of the electrostatic actuator, it is possible to effectively prevent the thinned portion of the silicon substrate from being broken.

In the method for manufacturing an electrostatic actuator according to the present invention, after the step of separating the electrode recess and the getter chamber by the sealing material, the getter chamber is cut from the portion that becomes the chip of the electrostatic actuator by dicing.
After the step of separating the electrode recess and the getter chamber with the sealing material, the chip of the electrostatic actuator can be reduced in size by cutting the getter chamber from the portion that becomes the chip of the electrostatic actuator by dicing.

Moreover, the manufacturing method of the electrostatic actuator which concerns on this invention etches a silicon substrate after the process of thinning a silicon substrate.
By etching the silicon substrate after the step of thinning the silicon substrate,
It is possible to effectively prevent the silicon substrate from being cracked or chipped during the processing of the silicon substrate.

The method for manufacturing an electrostatic actuator according to the present invention forms an equipotential contact that is electrically connected to the electrode and electrically connected to the silicon substrate in the step of forming the electrode in the recess for the electrode. .
By forming an equipotential contact that makes the electrode and the silicon substrate equipotential, discharge can be prevented from occurring during anodic bonding.

The method for manufacturing an electrostatic actuator according to the present invention includes a step of forming an insulating film on a silicon substrate and a step of providing an opening in the insulating film, and providing an equipotential contact at the opening. .
Since an opening is provided in the insulating film, and an equipotential contact is provided in the opening, an etching solution used in a subsequent manufacturing process does not enter the gap, thereby preventing the diaphragm from becoming inoperable. be able to.

In addition, the method for manufacturing an electrostatic actuator according to the present invention includes a plurality of electrostatic actuators by dicing a bonding substrate made of a glass substrate and a silicon substrate after the step of separating the electrode recess and the getter chamber with a sealing material. The chip is manufactured.
By dicing a bonded substrate consisting of a glass substrate and a silicon substrate, a plurality of electrostatic actuator chips can be manufactured, so that a large number of electrostatic actuator chips can be manufactured from a single silicon substrate, thereby improving productivity. Is possible.

Moreover, the manufacturing method of the electrostatic actuator which concerns on this invention cuts | releases the electrical connection of an equipotential contact and an electrode in the case of said dicing.
By disconnecting the electrical connection between the equipotential contact and the electrode at the time of dicing, it becomes possible to individually drive an actuator unit such as a diaphragm.

In the method for manufacturing an electrostatic actuator according to the present invention, the getter material is made of titanium, zirconium, an alloy containing titanium, or an alloy containing zirconium.
By constituting the getter material from titanium, zirconium, an alloy containing titanium, or an alloy containing zirconium, a gas such as oxygen in the gap can be effectively adsorbed.

A method for manufacturing a droplet discharge head according to the present invention is a method for manufacturing a droplet discharge head using any one of the above-described electrostatic actuator manufacturing methods.
By manufacturing a droplet discharge head using any one of the above-described electrostatic actuator manufacturing methods, a highly accurate droplet discharge head free from cracks and chips can be obtained.

A device manufacturing method according to the present invention manufactures a device using any one of the above-described electrostatic actuator manufacturing methods.
By manufacturing a device using any one of the above-described electrostatic actuator manufacturing methods, it is possible to obtain a highly accurate device free from cracks and chips.

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.
By manufacturing the droplet discharge device by applying the manufacturing method of the droplet discharge head described above, a droplet discharge device having high printing performance or the like can be obtained.

Embodiment 1. FIG.
FIG. 1 is an exploded perspective view showing a droplet discharge head according to Embodiment 1 of the present invention. The droplet discharge head according to the first embodiment is of an electrostatic drive type, and is of a face eject type that discharges droplets in a direction perpendicular to the nozzle substrate 3. The discharge method is
A side eject type of ejecting droplets in parallel with the nozzle substrate 3 may be used. Further, FIG. 1 shows that the nozzle substrate 3 is provided with two rows of nozzles 20 and the discharge chambers 5 and the electrodes 11 are also provided with two rows, but these may be provided in only one row. .

The droplet discharge head according to the first embodiment is mainly configured by bonding a cavity substrate 1, an electrode substrate 2, and a nozzle substrate 3. For example, the cavity substrate 1 has a thickness of 50 μm.
Made of single crystal silicon and subjected to the following predetermined processing. In FIG. 1, single crystal silicon having (110) plane orientation is used as the cavity substrate 1. The cavity substrate 1 is a reservoir for storing droplets discharged from the plurality of discharge chambers 5 and the nozzles 20 whose bottom wall is the diaphragm 4 by anisotropic wet etching of single crystal silicon. 7 is formed.
In addition, an insulating film is formed on the cavity substrate 1 on the side of the electrode substrate 2 to prevent short circuit between the diaphragm 4 and the electrode 11 and breakdown of the insulating film (not shown in FIG. 1). This insulating film is made of, for example, TEOS (Tetraethylorthosilicate Tetraetho
xysilane (ethyl silicate) film by CVD (Chemical Vapor Depo)
and a thickness of 0.1 μm.

The electrode substrate 2 is made of, for example, borosilicate glass having a thickness of 1 mm, and is joined to the diaphragm 4 side of the cavity substrate 1. In this electrode substrate 2, an electrode recess 10 a having a depth of 0.2 μm, for example, is formed by etching in accordance with the positions of the diaphragm 4 and the discharge chamber 5 of the cavity substrate 1. An electrode 11 is formed inside the electrode recess 10 a and is connected to the lead portion 12 and the terminal portion 13. The electrode recess 10a has at least the lead portion 12.
It is assumed that the part up to is formed. The electrode 11, the lead part 12, and the terminal part 13 are made of ITO (Indium Tin Oxide) doped with tin oxide or the like, and are formed in the electrode recess 10a by a thickness of 0.1 μm, for example, by sputtering. ing.

The plurality of electrodes 11 are provided so that their longitudinal directions are substantially parallel, and equipotential contacts 15 are provided at positions shifted in a direction perpendicular to the longitudinal direction of the electrodes 11 of the electrode substrate 2. The equipotential contact 15 is made of, for example, the same ITO as the electrode 11, and is formed in a state extending from the contact recess 10 b formed on the cavity substrate 1. Equipotential contact 1
5 will be described in detail later.
The electrode substrate 2 is provided with an ink supply port 17 for supplying droplets to the reservoir 7.

The nozzle substrate 3 is made of, for example, a silicon substrate having a thickness of 180 μm, and is bonded to the surface of the cavity substrate 1 opposite to the surface to which the electrode substrate 2 is bonded. The nozzle substrate 3 includes a discharge chamber 5.
A nozzle 20 communicating with the cavity substrate 1 is formed, and droplets are ejected from a surface opposite to the bonded surface of the cavity substrate 1. An orifice 21 for communicating the discharge chamber 5 and the reservoir 7 is provided on the surface of the nozzle substrate 3 to which the cavity substrate 1 is bonded. The orifice 21 may be provided in the cavity substrate 1.

FIG. 2 is a longitudinal sectional view of the droplet discharge head shown in FIG. 2A is a longitudinal sectional view in the longitudinal direction of the discharge chamber 5, and FIG. 2B is a longitudinal sectional view in the longitudinal direction of the contact recess 10b (equipotential contact 15). 2 shows only the right half of the droplet discharge head of FIG.
First, the operation of the droplet discharge head according to the first embodiment will be described with reference to FIG. The discharge chamber 5 stores droplets to be discharged from the nozzle 20, and the pressure in the discharge chamber 5 is increased by bending the diaphragm 4, which is the bottom wall of the discharge chamber 5. Discharge.
In order to bend the diaphragm 4, an oscillation circuit 23 (shown schematically in FIG. 2A) is connected to the terminal portion 13 connected to the electrode 11 and the cavity substrate 1, and the electrode 11 and the diaphragm 4 are connected. A potential difference is generated between the two. The gap between the diaphragm 4 and the electrode 11 is sealed with a sealing material 22.

The vibration plate 4 of the droplet discharge head according to the first embodiment includes a boron-doped layer 4a and an insulating film 4b. This boron-doped layer 4a has a high concentration of boron (about 5 × 10 ¹⁹ atoms).
ms / cm ³ or higher) are formed by doping, for example a single crystal silicon with an aqueous alkaline solution upon etching, a so-called etching stop layer etching rate becomes extremely slow. Since the boron-doped layer 4a functions as an etching stop layer, the thickness of the diaphragm 4 and the volume of the discharge chamber 5 can be formed with high accuracy. Insulating film 4b
Is composed of a TEOS film or the like as described above.

Further, as shown in FIG. 2B, a portion corresponding to the equipotential contact 15 of the insulating film 4b is removed, and this portion is an opening. An equipotential contact 15 made of ITO or the like is formed in the opening, and is connected to the boron-doped layer 4 a of the cavity substrate 1. As described above, the contact recess 10b is also formed on the extended line of the equipotential contact 15, and a wiring made of ITO or the like is formed therein. The equipotential contact 15 is formed, for example, so as to run on the cavity substrate 1 from the tip of the contact recess 10b (see FIG. 1).
In the first embodiment, the shape of the equipotential contact 15 is linear as shown in FIG.
The shape of the equipotential contact 15 may be other shapes.

FIG. 3 is a view of a glass substrate 2a serving as an electrode substrate 2 as viewed from a side to which a silicon substrate 1a (substrate serving as a cavity substrate 1) is bonded. FIG. 3 shows the periphery of a portion to be an individual droplet discharge head before the wafer-like glass substrate 2a is cut by dicing (described later). The manufacturing method of the droplet discharge head according to the first embodiment will be described in detail later.
As shown in FIG. 3, in the first embodiment, a recess 30 that becomes a getter chamber and an equipotential contact 15 are provided for each portion (chip) that becomes an individual droplet discharge head. Recess 3 to be a getter chamber
A getter material 31 made of titanium (Ti), zirconium (Zr), an alloy containing titanium, an alloy containing zirconium, or the like is formed inside 0, and the getter material 31 is formed during anodic bonding (described later). Gases such as oxygen that are generated and accumulated in the gap are adsorbed. The recess 30 serving as the getter chamber communicates with all the electrode recesses 10a through the recess 32.
The equipotential contact 15 has a function of making the cavity substrate 1 and the electrode 11 equipotential during anodic bonding. The equipotential contact 15 and the plurality of electrodes 11 are electrically connected via a wiring 33 such as ITO provided inside the recess 32 as shown in FIG. Two or more equipotential contacts 15 may be provided in a portion that becomes one droplet discharge head.

Here, as described above, the contact recess 10b is not formed in the equipotential contact 15 portion. Then, for example, an equipotential contact 15 made of ITO or the like is formed in such a manner as to ride on the surface of the glass substrate 2a from the tip of the contact recess 10b. The equipotential contact 15 is desirably formed simultaneously with the electrode 11. In this case, the equipotential contact 15 protrudes from the glass substrate 2a by 0.1 μm (the same thickness as the electrode 11). This equipotential contact 15 is connected to the boron-doped layer 4a at the opening of the insulating film 4b formed on the cavity substrate 1 (FIG. 2).
(See (b)).
A dicing line 1 and a dicing line 2 shown in FIG. 3 are portions that are cut when a chip of a droplet discharge head is cut out from a bonding substrate (described later) in which a silicon substrate 1a and a glass substrate 2a are bonded. The getter chamber 30 is cut off from the chip of the droplet discharge head by cutting the bonded substrate along the dicing line 1. This makes it possible to reduce the size of the droplet discharge head. Further, by cutting the bonding substrate along the dicing line 2, the wiring 33 connecting the equipotential contact 15 and the electrode 11 is cut off, and the electrical connection between the cavity substrate 1 and the electrode 11 is cut off. Thereby, after each droplet discharge head is cut out by dicing, the droplet discharge head can be driven.

4 and 5 are longitudinal sectional views showing manufacturing steps of the droplet discharge head according to Embodiment 1 of the present invention. 4 and 5 show a process of manufacturing the droplet discharge head shown in FIGS. 1 and 2, and particularly show a process of manufacturing the glass substrate 2a shown in FIG. 4 and 5
These show the AA cross section of the glass substrate 2a used as the electrode substrate 2 shown in FIG.
A method for manufacturing a droplet discharge head using the method for manufacturing an electrostatic actuator according to the present invention will be described below with reference to FIGS.

First, a glass substrate 2a made of, for example, borosilicate glass is polished on both sides to have a thickness of 1 mm (FIG. 4A), and then, for example, a thickness of 0.1 μm is formed on one side of the glass substrate 2a by sputtering.
The chromium film 40 is formed (FIG. 4B).
Next, resist patterning is performed on the surface of the chromium film 40 to form the electrode recesses 10a, the contact recesses 10b, and the recesses 32 (see FIG. 3), and a mixed liquid of a ceric ammonium nitrate aqueous solution and a perchloric acid aqueous solution. Is used to remove the chromium film 40 in the electrode recess 10a, the contact recess 10b, and the recess 32 (FIG. 3C). In FIG. 3C, the electrode recess 10a.
This shows a state where the portion of the chromium film 40 has been removed. In the process of FIG.
The recess 30 serving as a getter chamber is not formed.

Then, the glass substrate 2a is etched using an aqueous solution of ammonium fluoride using the chromium film 40 as an etching mask to form the electrode recess 10a, the contact recess 10b, and the recess 32 (FIG. 4D). Thereafter, the resist formed in the step of FIG. 3C is stripped using, for example, an organic stripping solution.
Then, all of the chromium film 40 formed on the surface of the glass substrate 2a is removed using a mixed solution of a ceric ammonium nitrate aqueous solution and a perchloric acid aqueous solution (FIG. 4E).
Next, ITO doped with tin oxide is sputtered to a thickness of, for example, 0.1 μm over the entire surface of the glass substrate 2a where the electrode recesses 10a and the like are formed (FIG. 5F).
)).
Thereafter, a resist is patterned on the surface of the ITO film 41 into the shape of the electrode 11 (including the lead portion 12 and the terminal portion 13), the wiring 33, and the equipotential electrode 15 (see FIG. 3), and then the ITO film 4
1 is etched using a mixed solution of nitric acid and hydrochloric acid to form an electrode 11 (lead portion 12 and terminal portion 13
), Wiring 33 and equipotential electrode 15 are formed (FIG. 5G). At this time, the electrode 11 is formed in the electrode recess 10 a and the wiring 33 is formed in the recess 32 as described above. Also equipotential contact 1
5 is formed on the glass substrate 2a.

And the recessed part 3 used as a getter chamber on the surface in which the electrode recessed part 10a etc. of the glass substrate 2a were formed
0 is formed at a depth of 5 μm, for example, by sandblasting. Further, a through-hole serving as the ink supply port 17 is formed in the glass substrate 2a by sandblasting or the like (FIG. 5H)
. The recess 30 serving as a getter chamber is provided with an electrode recess 10a via a recess 32 as shown in FIG.
To communicate with.
Then, for example, a getter material 31 is formed in a thickness of 3 μm in the recess that becomes the getter chamber 30 using a metal mask (FIG. 5I). As described above, titanium, zirconium, an alloy containing titanium, an alloy containing zirconium, or the like can be used as the material of the getter material 31. Thereby, the glass substrate 2a as shown in FIG. 3 is completed.

6 and 7 are longitudinal sectional views showing the manufacturing process of the droplet discharge head according to Embodiment 1 of the present invention. 6 and 7 show a process of manufacturing the droplet discharge head shown in FIGS. 1 and 2, and in particular, a process of manufacturing the silicon substrate 1a to be the cavity substrate 1 and the silicon substrate 1a and the glass substrate 2a. A process of manufacturing a droplet discharge head after bonding is shown. 6 and 7 mainly show a longitudinal section in the longitudinal direction of the discharge chamber 5 (cross section in FIG. 2A), but a longitudinal section in the longitudinal direction of the contact recess 10b (FIG. 2B). If a cross section is indicated, it shall be indicated. Further, FIG. 6 and FIG. 7 show a peripheral portion of a portion to be a chip of each droplet discharge head.

First, for example, one surface of a silicon substrate 1a having a surface orientation of (110) and a low oxygen concentration is mirror-polished to produce a silicon substrate 1a having a thickness of 220 μm, and boron-doped on the surface opposite to the surface on which the discharge chamber 5 and the like are formed. The layer 4a is formed (FIG. 6A). Specifically, the silicon substrate 1a is made of B ₂
The quartz boat is set in a quartz boat so as to face a solid diffusion source mainly composed of O ₃ , and this quartz boat is placed in, for example, a vertical furnace. Then, the inside of the vertical furnace is set to a nitrogen atmosphere having a temperature of 1050 ° C.
Boron is diffused in the silicon substrate 1a while maintaining the time, and the boron doped layer 50 is formed.
At this time, the charging temperature of the silicon substrate 1a is set to 800 ° C., and after the temperature is raised to 1050 ° C., the temperature when the silicon substrate 1a is taken out is also set to 800 ° C. Thereby, the silicon substrate 1
It is possible to quickly pass through the region of 600 ° C. to 800 ° C. where the growth rate of oxygen defects of a is fast, and the growth of oxygen defects can be suppressed.

In the above boron diffusion step, a SiB ₆ film (not shown) is formed on the surface of the boron doped layer 4a. By oxidizing it in an oxygen and water vapor atmosphere at a temperature of 600 ° C. for about 1 hour 30 minutes, It can be chemically changed to B ₂ O ₃ and SiO ₂ that can be etched with a hydrofluoric acid aqueous solution. After the SiB ₆ film is chemically changed to B ₂ O ₃ and SiO ₂ in this way, B ₂ O ₃ and SiO ₂ are etched away with a buffered hydrofluoric acid solution.

And, for example, plasma CVD (Chemical Vapor Deposition)
n), an insulating film 4b made of TEOS having a thickness of 0.1 μm is formed on the surface of the silicon substrate 1a on the boron doped layer 4a side (FIG. 6B). The conditions for forming the insulating film 4b at this time are, for example, a temperature of 360 ° C., a high frequency output of 250 W, a pressure of 66.7 Pa (0.5 Torr), TE
OS flow rate 100 cm ³ / min (100 sccm), oxygen flow rate 1000 cm ³ / min (1000 s
ccm).
Then, a resist is patterned in the shape of the opening 50 for forming the equipotential contact 15 on the surface on which the boron doped layer 4a is formed. Then, the insulating film 4b at the opening 50 is removed by etching the silicon substrate 1a (FIG. 6 (b ′)). Note that FIG.
(B ') has shown the longitudinal cross-section (cross section of FIG.2 (b)) of the recessed part 10b for contacts in the longitudinal direction.

Next, the silicon substrate 1a shown in FIG. 6 (b ′) and the glass substrate 2a processed up to FIG. 5 (i) are joined by anodic bonding to form a joined substrate (FIG. 6 (c), FIG. 6 (c ′)
). This anodic bonding is performed, for example, by heating the silicon substrate 1a and the glass substrate 2a to 360 ° C. and then applying a voltage of 800 V between the silicon substrate 1a and the glass substrate 2a. In order to prevent damage to ITO or the like during anodic bonding, it is desirable to prevent a current of, for example, 10 mA or more from flowing. During this anodic bonding, the equipotential contact 15 is connected to the boron doped layer 4a of the cavity substrate 1 in the opening 50 (see FIG. 6C ′). Note that FIG.
(C ') has shown the longitudinal cross-section (cross section of FIG.2 (b)) of the recessed part 10b for contacts in the longitudinal direction.
In the anodic bonding shown in FIGS. 6C and 6C ′, the silicon substrate 1a and the glass substrate 2 are used.
The glass is electrolyzed at the interface a to generate oxygen, or gas is generated from the surfaces of the silicon substrate 1a and the glass substrate 2a by heating, but these gases accumulated in the gap are adsorbed by the getter material 31. . For this reason, it can prevent that the pressure in a gap becomes high (refer FIG. 3).
During the anodic bonding, the electrode recess 10a, the recess 32, the getter chamber, and the like are hermetically sealed.

After anodic bonding of the silicon substrate 1a and the glass substrate 2a, the silicon substrate 1a is thinned to a thickness of 60 μm, for example, by grinding. Then, for example, the silicon substrate 1a is etched by 10 μm using a 32 wt% potassium hydroxide aqueous solution to remove the work-affected layer generated during grinding (FIG. 6D). Thus, the thickness of the silicon substrate 1a is 5
0 μm. Note that all the steps of thinning the silicon substrate 1a in FIG. 6D may be performed by etching.
Then, a 1.5 μm thick T is formed on the entire surface of the silicon substrate 1a by plasma CVD.
An EOS film 51 is formed. The film formation conditions of the TEOS film 51 by plasma CVD are, for example, a temperature of 360 ° C., a high frequency output of 700 W, a pressure of 33.3 Pa (0.25 Torr), a TE
OS flow rate 100 cm ³ / min (100 sccm), oxygen flow rate 1000 cm ³ / min (1000 s
ccm). The TEOS film 51 serves as an etching mask for subsequent etching with an aqueous potassium hydroxide solution.

The TEOS film 51 is patterned on the silicon substrate 1a with a resist for forming the concave portion 5a serving as the discharge chamber 5, the concave portion 7a serving as the reservoir 7, and the electrode lead-out portion, and becomes the discharge chamber 5 using, for example, buffered hydrofluoric acid solution. The TEOS film 51 in the concave portion 5a, the concave portion 7a serving as the reservoir 7 and the electrode extraction portion is removed by etching. Here, the electrode lead-out portion refers to a portion where the terminal portion 13 is exposed (see FIG. 2B).
Thereafter, the silicon substrate 1a is etched and thinned with a 35% by weight aqueous potassium hydroxide solution until the thickness of the concave portion 5a serving as the discharge chamber 5 and the portion forming the electrode lead-out portion become 10 μm. At this time, the etching of the portion of the concave portion 7 a that becomes the reservoir 7 is delayed by half-etching the TEOS film 51.
Further, the silicon substrate 1a is etched with a 3% by weight aqueous potassium hydroxide solution until the etching stop by the boron-doped layer 4a is sufficiently effective in the portion that becomes the recess 5a that becomes the discharge chamber 5 and the portion that forms the electrode extraction portion. (FIG. 7 (e)).

Here, the term “etching stop” refers to a state in which bubbles are no longer generated from the surface of the silicon substrate 1a to be etched, and etching is performed until no bubbles are actually generated. As a result, the concave portion 5a serving as the discharge chamber 5, the concave portion 7a serving as the reservoir 7, and the electrode extraction portion are formed.
As described above, by performing etching using two types of aqueous potassium hydroxide solutions having different concentrations, the surface roughness of the diaphragm 4 which is the bottom wall of the discharge chamber 5 can be suppressed to 0.05 μm or less. The discharge performance of the droplet discharge head 10 can be stabilized. Here, the thickness of the diaphragm 4 is 0.8 μm.

Then, all the TEOS film 51 formed on the silicon substrate 1a is removed using a hydrofluoric acid aqueous solution.
Thereafter, the electrode extraction portion of the silicon substrate 1a is removed by RIE (Reactive Ion Etching) (FIG. 4G). This RIE is a kind of dry etching. For example, the output is 200 W, the pressure is 40 Pa (0.3 Torr), and the CF ₄ flow rate is 30 c.
This is performed for 30 minutes using a silicon mask under the condition of m ³ / min (30 sccm). At this time, the inside of the gap is released to the atmosphere.

Then, a sealing material 22 such as an epoxy resin is poured along the end of the electrode extraction portion to seal the gap (electrode recess 10a) between the diaphragm 4 and the electrode 11 (FIG. 7 (h)). . As a result, the gap between the diaphragm 4 and the electrode 11 is sealed again. Sealing material 2
2 is formed on the left side of the dicing line 2 in FIG.
As a result, the gap (electrode recess 10a) between the diaphragm 4 and the electrode 11 and the getter chamber are spatially separated.

Then, the nozzle substrate 3 is bonded to the silicon substrate 1a using an epoxy adhesive or the like (
FIG. 7 (i)).
Finally, dicing is performed along the dicing line 1 and the dicing line 2 shown in FIG. 3 and divided into individual chips, thereby completing a plurality of droplet discharge heads (FIG. 7J).
). In this step, the getter chamber is cut from the chip of the droplet discharge head by performing dicing along the dicing line 1 as described above. Further, by performing dicing along the dicing line 2, the electrical connection between the equipotential contact 15 and the electrode 11 is broken (see FIG. 3). In this dicing step, the equipotential contact 15 may also be cut.

In the first embodiment, a recess 30 serving as a getter chamber communicating with the electrode recess 10a is formed in the glass substrate 2a, and a getter material 31 is formed therein, so that a gas such as oxygen generated during anodic bonding is formed. Can be prevented, and when the concave portion 5a or the like to be the discharge chamber 5 is formed on the silicon substrate 1a, it is possible to prevent the thinned portion (the diaphragm 4 or the like) from cracking. Further, since the electrode recess 10a and the getter chamber are separated by the sealing material 22, when the driving of the droplet discharge head is repeated, the gas in the gap between the cavity substrate 1 and the electrode substrate 2 is excessively adsorbed. Thus, the vibration plate 4 and the electrode 11 can be prevented from sticking.
Furthermore, since the silicon substrate 1a is thinned after the silicon substrate 1a is anodically bonded to the glass substrate 2a, the silicon substrate 1a can be easily handled, and the silicon substrate 1a can be prevented from being cracked or chipped. This also makes it possible to increase the diameter of the silicon substrate 1a and to manufacture a large number of droplet discharge head chips from a single silicon substrate 1a, thereby improving productivity.
In addition, since the equipotential contact 15 for making the electrode 11 and the silicon substrate 1a equipotential is formed, it is possible to prevent discharge from occurring during anodic bonding.

Embodiment 2. FIG.
FIG. 8 is a view showing an example of a droplet discharge device according to Embodiment 2 of the present invention. A droplet discharge device 100 shown in FIG. 8 is a general ink jet printer, and includes a droplet discharge head obtained by the method of manufacturing a droplet discharge head shown in the first embodiment. Since the droplet discharge head obtained by the manufacturing method of the droplet discharge head shown in the first embodiment is a droplet discharge head with few cracks and chips, the droplet discharge apparatus 100 according to the second embodiment is capable of printing. It has high performance. In addition, the droplet discharge apparatus 100 as shown in FIG. 8 can be manufactured using a well-known manufacturing method.

The droplet discharge head obtained by the method of manufacturing a droplet discharge head shown in Embodiment 1 of the present invention is not limited to the inkjet printer as shown in FIG. It can also be used for manufacturing color filters and DNA devices.
In addition, the manufacturing method of the electrostatic actuator according to the first embodiment of the present invention can be used not only for manufacturing a droplet discharge head but also for manufacturing other devices such as a capacitive pressure sensor and an optical MEMS device. . For such a device, for example, Japanese Patent Application Laid-Open No. 2004-2457.
See No. 53 publication.

The manufacturing method of the electrostatic actuator, the manufacturing method of the droplet discharge head, the manufacturing method of the device, and the manufacturing method of the droplet discharge device according to the present invention are not limited to the above-described embodiments, but the idea of the present invention. It can be changed within the range. For example, the equipotential contact 15 is not necessarily provided.

1 is an exploded perspective view showing a droplet discharge head according to Embodiment 1 of the present invention. FIG. 2 is a longitudinal sectional view of the droplet discharge head shown in FIG. 1. The figure which looked at the glass substrate used as an electrode substrate from the side by which a silicon substrate is joined. FIG. 3 is a longitudinal sectional view illustrating a manufacturing process of a droplet discharge head according to Embodiment 1 of the invention. FIG. 5 is a longitudinal sectional view showing a manufacturing process continued from FIG. 4. FIG. 3 is a longitudinal sectional view illustrating a manufacturing process of a droplet discharge head according to Embodiment 1 of the invention. FIG. 7 is a longitudinal sectional view showing a manufacturing process continued from FIG. 6. The figure which showed the example of the droplet discharge apparatus which concerns on Embodiment 2 of this invention.

Explanation of symbols

1 cavity substrate, 2 electrode substrate, 3 nozzle substrate, 4 diaphragm, 5 discharge chamber, 7
Reservoir, 10a electrode recess, 10b contact recess, 11 electrode, 12 lead, 1
3 terminal portion, 15 equipotential contact, 17 ink supply port, 20 nozzle, 21 orifice, 22 sealing material, 23 oscillation circuit, 100 droplet discharge device.

Claims (12)

Forming an electrode recess for forming an electrode on the glass substrate, and forming an electrode in the electrode recess;
A recess that serves as a getter chamber for accommodating a getter material that adsorbs gas in the electrode recess is formed in the glass substrate, and the getter material is formed in the recess that serves as the getter chamber. Forming a film;
A step of thinning the silicon substrate after anodically bonding the silicon substrate to the glass substrate;
A method of manufacturing an electrostatic actuator, comprising: sealing the electrode recess with a sealing material to separate the electrode recess and the getter chamber with the sealing material. 2. The getter chamber is provided for each chip of the electrostatic actuator.
The manufacturing method of the electrostatic actuator of description. 3. The static electricity according to claim 1, wherein after the step of separating the electrode recess and the getter chamber by the sealing material, the getter chamber is cut by dicing from a portion to be a chip of an electrostatic actuator. Manufacturing method of electric actuator. The method for manufacturing an electrostatic actuator according to claim 1, wherein the silicon substrate is etched after the step of thinning the silicon substrate. 5. The step of forming an electrode in the recess for an electrode forms an equipotential contact that is electrically connected to the electrode and electrically connected to the silicon substrate. A method for producing the electrostatic actuator according to 1. 6. The method of manufacturing an electrostatic actuator according to claim 5, further comprising: forming an insulating film on the silicon substrate; and providing an opening in the insulating film, and providing an equipotential contact in the opening. Method. A plurality of electrostatic actuator chips are manufactured by dicing the bonding substrate made of the glass substrate and the silicon substrate after the step of separating the recess for the electrode and the getter chamber by the sealing material. A method for manufacturing an electrostatic actuator according to claim 5 or 6. 8. The method of manufacturing an electrostatic actuator according to claim 7, wherein the equipotential contact and the electrode are disconnected from each other during the dicing. The method for manufacturing an electrostatic actuator according to claim 1, wherein the getter material is made of titanium, zirconium, an alloy containing titanium, or an alloy containing zirconium. A method for manufacturing a droplet discharge head, wherein the droplet discharge head is manufactured using the method for manufacturing an electrostatic actuator according to claim 1. A device manufacturing method, wherein a device is manufactured using the electrostatic actuator manufacturing method according to claim 1. 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 10.

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