JPH11285275A - Electrostatic actuator, ink-jet head, silicon substrate, etching mask, and manufacture of the silicon substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate making a through-hole of an ink-jet head, reducing the size of the through-hole by providing in the ink-jet head an opposite electrode to ensuring continuity to a wiring pattern disposed in its opening portion facing a vibrational plate, and by providing in it a driving means for displacing the vibrational plate through applying voltages from the wiring pattern to the vibrational plate and the opposite electrode. SOLUTION: A silicon substrate 2 is a silicon single crystal substrate whose surface is (110) bidirectional, and applying a wet anisotropic etching from its surface to its inside, five independent ink chambers 5 are processed. Making a thin-walled bottom wall (vibrating plate) 51 in each independent ink chamber 5, the bottom wall 51 functions as a vibrational plate capable of being diplaced elastically in the outer direction of its surface. Furthermore, an opposite space between the vibrational plate 51 and a segment electrode (facing electrode) 18 disposed oppositely to the vibrational plate 51 is identical to a difference between the depth of a recessed portion and the thickness of the segment electrode 18. Then, when applying a driving voltage from a voltage applying means 21 to the opposite space between the vibrational plate 51 and the facing opposite electrode 18, deflecting the vibrational plate 51 on the side of the facing opposite electrode 18, it is displaced to expand the volume of the ink chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrostatic actuator, an ink jet head, a silicon substrate, an etching mask, and a method for manufacturing a silicon substrate. In particular, the present invention relates to an electrostatic actuator and an inkjet head driven by an electrostatic force generated by applying a voltage between a diaphragm and a counter electrode, and a method of manufacturing these.

[0002]

2. Description of the Related Art In an ink jet head of an ink jet printer, fine printing is required. Such an ink jet head is manufactured by forming an actuator having a minute structure for discharging ink on a silicon wafer by using a semiconductor fine processing technique. In addition to the inkjet head, a microactuator such as a micromirror has been proposed.

[0003] In such an actuator having a minute structure, an electrostatic force can be used as a driving source. For example, the present applicant has disclosed an inkjet head that discharges ink droplets using electrostatic force as disclosed in Japanese Patent Laid-Open No. 5-50 / 1993.
601 and JP-A-6-70882.

In an ink jet head of this type, the bottom surface of an ink flow path communicating with an ink nozzle is formed as an elastically deformable diaphragm. Substrates are arranged facing the diaphragm at regular intervals.

[0005] A plurality of ink nozzles, ink flow paths, and diaphragms are formed, and opposing electrodes facing the respective diaphragms are arranged on the substrate.

An opening (through hole) is formed in the diaphragm and the counter electrode.
, The wiring patterns are conductive, and when a voltage is applied between these wiring patterns, an electrostatic force is generated on the diaphragm and the counter electrode. The diaphragm is displaced (vibrated) by electrostatic attraction toward the substrate by the electrostatic force.

On the other hand, since the space (vibration chamber) between the vibration plate and the counter electrode is hermetically sealed by a sealing member, the internal pressure of the ink flow path varies with the vibration of the vibration plate. Is generated, and ink droplets are ejected from the ink nozzle.
By controlling the voltage applied to the wiring pattern, a so-called ink-on-demand system that discharges ink droplets only when necessary for recording is realized.

The diaphragm of an electrostatic actuator such as an ink jet head can be formed by wet anisotropic etching utilizing anisotropy of silicon. In this case, in the silicon wafer having the plane orientation (110), the wall surface (plane orientation (110)) of the hole formed by the etching is perpendicular to the front surface and the rear surface, so that the silicon wafer has the plane orientation (100). Thus, the density of the diaphragm can be increased.

On the other hand, when a silicon wafer having a (110) plane orientation is wet-anisotropically etched to form a through-hole for disposing a wiring pattern to be conducted to a counter electrode, the through-hole in the (110) plane on the front or back surface is formed. The shape of the hole is a parallelogram with one of the inner angles being 70.19 degrees.

[0010]

However, if the plane shape of the through hole is a parallelogram, the size of the through hole becomes large. For this reason, the size of an actuator such as an inkjet head becomes large, and
There has been a problem that the number of wafers that can be manufactured from one wafer is reduced, resulting in an increase in cost. In addition, since the through hole is large, the handling property in production is deteriorated, and there has been a problem that the strength is reduced.

The present invention has been made to solve such problems, and an object thereof is to provide an electrostatic actuator, an ink jet head, a silicon substrate, an etching mask, and a method of manufacturing a silicon substrate. . In particular, it is an object of the present invention to provide an inexpensive electrostatic actuator and an ink-jet head that are easy to handle in production and are inexpensive, and a method of manufacturing the same.

[0012]

As means for solving the above-mentioned problems, the following invention is provided.

According to the electrostatic actuator of the present invention, (11)
0) An opening having a polygonal shape obtained by superimposing a plurality of parallelograms continuous on a plane, and an opening where a wiring pattern is arranged; A (110) silicon substrate having a vibrating plate displaced by the vibrating plate, a counter electrode disposed to face the vibrating plate and conducting to a wiring pattern disposed in the opening, and a vibrating plate and a counter electrode from the wiring pattern. Driving means for applying a voltage to displace the diaphragm.

It is preferable that the pitch of the parallelograms overlapping the openings is substantially the same as the pitch of the wiring patterns.

It is desirable that the electrostatic actuator of the present invention further includes a sealing member for hermetically sealing a vibration chamber formed by the diaphragm and the counter electrode.

In the electrostatic actuator of the present invention, the sealing member is an epoxy-based low-temperature thermosetting type and has a viscosity of 1,000.
It is desirably cP to 14000 cP.

The ink jet head according to the present invention is characterized in that (11)
0) An opening having a polygonal shape obtained by superimposing a plurality of parallelograms continuous on a plane, and an opening where a wiring pattern is arranged; A (110) silicon substrate having a vibrating plate displaced by the vibration plate, an opposing electrode disposed opposite to the vibrating plate and conducting to a wiring pattern disposed in the opening, and applying a voltage to the wiring pattern, A drive means for generating static electricity between the plate and the counter electrode and displacing the diaphragm, and a hermetic seal between the diaphragm and the counter electrode to provide an ink chamber in which the pressure fluctuates due to the displacement of the diaphragm. A stop member and an ink nozzle that communicates with the ink chamber and that ejects ink droplets stored in the ink chamber due to pressure fluctuations in the ink chamber are provided.

Further, the ink jet head of the present invention comprises:
A diaphragm, an ink chamber, and an ink nozzle are sectioned and formed.
10) It is desirable that a plurality of wiring patterns are provided on the silicon substrate, and a plurality of wiring patterns electrically connected to the respective counter electrodes of the plurality of diaphragms are arranged in the opening. in this case,
It is preferable that the pitch of the parallelograms overlapping the opening is substantially the same as the pitch of the wiring pattern.

The (110) silicon substrate of the present invention comprises
10) An opening having a polygonal shape in which a plurality of parallelograms continuous on a plane are overlapped, and the pitch of the overlap of the parallelograms is not more than the thickness of the (110) silicon substrate. Be composed.

In the (110) silicon substrate of the present invention, it is preferable that one of the inner angles of the parallelogram is 70.19 degrees.

The anisotropic etching mask for a (110) silicon substrate according to the present invention has a vertex of a polygon in which a parallelogram having one inner angle of 70.19 degrees is overlapped in parallel with its long side. , The mask pattern has a shape in which the correction pattern is extended in parallel with the long side of the parallelogram from the vertex where the inner angle is 289.81 degrees.

According to the method of manufacturing a (110) silicon substrate of the present invention, among the vertices of a polygon formed by superposing a parallelogram having an inner angle of 70.19 degrees in parallel with its long side, the inner angle is Masking the (110) plane of the (110) silicon wafer with a mask pattern in which the correction pattern is extended from the vertex at 289.81 degrees in parallel to the long side of the parallelogram; And a step of anisotropically etching the silicon wafer.

In the method of manufacturing a (110) silicon substrate according to the present invention, it is preferable that the length of the correction pattern is set based on an etch rate of anisotropic etching.

In the method for manufacturing a (110) silicon substrate according to the present invention, two types of lengths of the correction pattern of the mask pattern are set based on the etch rates of both surfaces of the (110) silicon wafer, and the two types of the mask patterns are set. With the mask pattern, both sides of the (110) silicon wafer can be masked, and the (110) silicon wafer can be anisotropically etched from both sides.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet head which is an electrostatic actuator to which the present invention is applied will be described with reference to the drawings.

FIG. 1 is a sectional view of an ink jet head as an electrostatic actuator to which the present invention is applied, FIG. 2 is a perspective view thereof, and FIG. 3 is an exploded perspective view thereof.

This embodiment is a face-ejection type ink jet head in which ink droplets are ejected from nozzles provided on a nozzle plate.

As shown in these figures, the ink jet head 1 has a silicon substrate 2 sandwiched therebetween, a nozzle plate 3 also made of silicon on the upper side, and a glass substrate 4 made of borosilicate glass whose thermal expansion coefficient is close to that of silicon on the lower side. Are laminated in a three-layer structure.

The surface of the central silicon substrate 2 is (11)
0) A silicon single crystal substrate having a plane orientation and a thickness of 180
μm. When wet anisotropic etching is performed on silicon having a plane orientation of (110), the plane perpendicular to the silicon surface becomes 4
The surface is formed. For this reason, when a groove is formed on a silicon wafer having a plane orientation of (110) by wet anisotropic etching, compared with a case where a silicon wafer having a plane orientation of (100) is formed.
The density of the grooves can be increased.

By performing wet anisotropic etching from the surface of the silicon substrate 2, grooves each functioning as five independent ink chambers 5 and one common ink chamber 6 are formed.

In this embodiment, an etching solution used for wet anisotropic etching of silicon can be a 20% by weight aqueous solution of KOH heated to 80 ° C. Note that this concentration can be changed according to the situation. Further, the composition is not limited to the KOH aqueous solution. For example, an alkaline aqueous solution such as an aqueous ammonia solution or an organic amine-based alkaline aqueous solution can be used.

The nozzle plate 3 is a silicon single crystal having a thickness of 180 μm, and has a (100) plane orientation. By performing wet anisotropic etching from the back surface of the nozzle plate 3, five nozzle grooves 7 are formed at positions corresponding to the front end portions of the respective ink chambers 5. In order to make the ink chambers 6 communicate with each other, a groove that functions as an ink supply path 9 is formed at a position opposite to the nozzle with respect to each ink chamber. Further, by performing dry anisotropic etching from the surface of the nozzle plate 3, a nozzle hole 8 is formed at a position corresponding to the nozzle groove 7.

By joining the nozzle plate 3 and the silicon substrate 2, one common ink chamber 6 and five independent ink chambers 5 communicate with each other through ink supply paths 9. The five independent nozzle holes 8 communicate with the respective ink chambers 5.

In the present embodiment, the nozzle plate 3 and the silicon substrate 2 can be directly bonded by positioning and bonding, and then heating to 1000 ° C. The bonding between the nozzle plate 3 and the silicon substrate 2 is not limited to the direct bonding. For example, a gold film is formed on the bonding interface between the nozzle plate 3 and the silicon substrate 2 in advance to 2000 Å, and then the nozzle plate 3 and the silicon substrate 2 are bonded together. The substrate 2 is brought into close contact with the substrate 2 to 400 degrees Celsius.
By heating to ℃, eutectic bonding can be performed at a low temperature. Further, the nozzle plate 3 and the silicon substrate 2 can be joined with an adhesive.

Each of the independent ink chambers 5 has a thin bottom wall (diaphragm) 51 and is configured to function as a vibrating plate that can be elastically displaced in an out-of-plane direction, that is, in the vertical direction in FIG. Have been.

Next, in the glass substrate 4 located below the silicon substrate 2, the upper surface of the glass substrate 4, which is to be bonded to the silicon substrate 2, is located at a position corresponding to each ink chamber 5 of the silicon substrate 2. A recess 16 that forms the vibration chamber 15 that is etched shallowly and a recess that communicates with the recess 16 and forms the passage 17 are formed. In addition, ITO (Indium Tin Oxicid) is provided on the concave surface of the glass substrate 4.
The segment electrode 18 of e) is formed. The segment electrode 18 has a wiring portion 19 and a terminal portion 20.

Here, the interval between the bottom wall (diaphragm) 51 and the segment electrode (opposite electrode) 18 opposed thereto, that is, the interval (gap length) G between the vibration chambers 15
Is the difference between the depth of the recess 16 and the thickness of the segment electrode 18.

An ink supply hole 10 is formed in the bottom surface of the common ink chamber 6 of the silicon substrate 2 by performing dry etching from the back side of the silicon substrate. An ink supply port 11 is also formed on the glass substrate 4 at a position corresponding to the ink supply hole 10. The ink is supplied from an external ink tank (not shown) to the common ink chamber 6 through the ink supply port 11 and the ink supply hole 10. The ink supplied to the common ink chamber 6 is supplied to each independent ink chamber 5 through each ink supply path 9.

In the silicon substrate 2, through holes 13 for taking out the segment electrode terminal portions 20 are formed by performing wet anisotropic etching from the front and back surfaces of the silicon substrate 2. According to such a forming method, the side surface on which the through hole 13 is formed is substantially constituted by a (111) crystal plane, and the discontinuous portion 14 is formed.

Here, the shape of the through hole will be described with reference to FIG. 4, FIG. 5, and FIG. FIG. 4 shows a silicon wafer 1 constituting a silicon substrate 2 to which the present invention is applied.
It is a top view which shows the planar shape of No. 01. FIG. 5 is a plan view showing a planar shape of a silicon wafer 31 constituting a silicon substrate 32 of a conventional example. FIG. 6 is an explanatory diagram showing the shape of a mask pattern for providing a through hole (opening) in a silicon substrate of an inkjet head.

In FIG. 4, according to the processing method described above,
A groove functioning as an ink chamber 5, a common ink chamber 6, an ink supply hole 10, a common electrode terminal 22, and a through hole 13 are formed. Therefore, the silicon substrate 2 is formed by cutting along the dashed line shown in FIG. Through hole 13
Has a configuration in which parallelograms indicated by broken lines are continuously superimposed.

In this embodiment, 1 is
Although one silicon substrate 2 is configured, the present invention is not limited to this.

The silicon wafer 31 is a silicon single crystal substrate whose surface has a (110) plane orientation. Ink chamber 35,
Groove serving as common ink chamber 36, ink supply hole 4
The common electrode terminal 42 and the through-hole 43 are formed by the same processing method as in this embodiment. However, the through hole 43
Is formed by one parallelogram. Therefore, the through hole 43 is larger than the through hole 13 and
The silicon substrate 32 (shape indicated by a chain line in FIG. 5) is larger than the silicon substrate 2.

In this embodiment, as shown in FIG. 3, the pitch P of the parallelograms of the through holes 13 is set to 100 μm, which is a dimension of the silicon substrate 2 having a thickness of 180 μm or less. The smaller the pitch P is, the smaller the formed through hole can be. The nozzle plate 3 has a common electrode terminal 22 formed on the silicon substrate 2.
And the segment electrode terminal 2 formed on the glass substrate 4
In order to take out 0, a through hole 12 slightly larger than the through hole 13 formed in the silicon substrate 2 is formed by performing wet anisotropic etching from the front and back surfaces of the nozzle plate 3. Further, the pitch of each segment electrode terminal 20 formed on the glass substrate 4 is formed so as to be substantially the same as the above-mentioned pitch P of the parallelogram overlapping of the through holes 13. That is, the pitch of each segment electrode terminal 20 was 100 μm.

As described above, by making the pitch P of the through holes 13 and the pitch of the segment electrode terminals 20 the same, the segment electrode terminals 20 are surely arranged at a portion where the side surface of the through hole 13 becomes the (111) plane. Can be set up. That is, it is possible to prevent an unstable surface such as a slight etching residue formed by a correction pattern in a mask pattern described later from interfering with the segment electrode terminal 20 by joining the glass substrate 4 and the silicon substrate 2. It becomes possible. Further, this makes it possible to stably match the capacitance of each actuator, and to obtain an actuator having the same characteristics in the same head even if the shape of the through hole 13 is complicated.

A mask pattern for forming such a through hole 43 in which parallelograms are overlapped will be described with reference to FIG. FIG. 6A shows a desired shape of the through hole. In the parallelogram of the through hole, one of the inner angles is (1
10) The angle is 70.19 degrees which matches the crystal structure of the silicon substrate.

FIGS. 6B and 6C show the shapes of the respective mask patterns on both surfaces when such a through hole is subjected to wet anisotropic etching from both surfaces. FIG. 6 (b),
The shape of the mask pattern shown in FIG.
In the polygon of the shape of the through hole shown in FIG.
The correction pattern extends from the vertex at 89.81 degrees, that is, the vertex pointed inward, parallel to the long side of the parallelogram. In this embodiment, the correction pattern of the mask pattern shown in FIG. 6B is longer than the correction pattern of the mask pattern shown in FIG. This is because the back surface is doped with boron, so that the etch rate from the front surface is different from the etch rate from the back surface.

In this embodiment, the correction pattern from the front surface has a length of about 210 μm, the correction pattern from the back surface has a length of about 105 μm, and the width is about 20 μm. The width of the correction pattern can be set in consideration of a certain margin to the processing limit.

FIG. 6D shows the state shown in FIG. 6B and FIG.
The mask pattern shown in FIG.
It is explanatory drawing for comparing with the desired shape of the through-hole shown in (a). The shape obtained by superposing both mask patterns and removing the correction pattern in parallel with the sides of the parallelogram is shown in FIG.
It can be seen that the shape of the through hole shown in FIG.

The pitch of the correction pattern, that is,
It is desirable that the pitch P of the parallelogram overlap is the same as the pitch of the counter electrode. This is to prevent the remaining portion from overlapping with the counter electrode even if silicon in the portion masked by the correction pattern remains. Therefore, this pitch is determined by the processing ability when connecting the counter electrode and the external circuit, and as described above, it is about 100 μm in this embodiment.

After bonding the silicon substrate 2 and the glass substrate 4, a sealing adhesive 30 is applied through the through holes 13 of the silicon substrate 2. Thereby, the vibration chamber 15 can be hermetically sealed.

As shown in FIG. 1, the voltage applying means 21
A drive voltage is applied between the bottom wall (diaphragm) 51 of the silicon substrate 2 and the segment electrode (counter electrode) 18 according to an external print signal (not shown). One output of the voltage applying means 21 is connected to a terminal portion 20 of each segment electrode 18, and the other output is connected to a common electrode terminal 22 formed on the silicon substrate 2.

Since the silicon substrate 2 itself has conductivity,
A voltage can be supplied from the common electrode terminal 22 to the common electrode of the bottom wall (diaphragm) 51. Since the silicon substrate 2 has a relatively high electric resistance, the voltage supplied to the common electrode drops. In order to avoid such a voltage drop, it is necessary to lower the electric resistance. If a thin film of a conductive material such as gold is formed on one surface of the silicon substrate 2 by using a vapor deposition method, a sputtering method, or the like, the electric resistance can be reduced. In this embodiment, the silicon substrate 2 and the glass substrate 4
An anode junction is used for the connection with the substrate, and a conductive film is formed on the flow channel forming surface side of the silicon substrate 2.

In the ink jet head 1 configured as described above, when the driving voltage from the voltage applying means 21 is applied between the bottom wall (diaphragm) 51 and the segment electrode (counter electrode) 18, a voltage is applied between them. An electrostatic force is generated by the charged electric charges, and the bottom wall (diaphragm) 51 is bent and displaced toward the segment electrode (counter electrode) 18, and the volume of the ink chamber 5 is enlarged.

When a pulsed voltage is applied, when the charged charge is discharged, the bottom wall (diaphragm) 51 is moved by the elastic restoring force of the segment electrode (counter electrode) 18.
The ink chamber 5 is displaced by returning from the side, and the volume of the ink chamber 5 is rapidly contracted. Due to the change in the internal pressure in the ink chamber 5 generated at this time, a part of the ink filling the ink chamber 5 is ejected as an ink droplet from the nozzle hole 8 communicating with the ink chamber.

Next, the hermetic sealing of the vibration chamber 15 will be described with reference to FIGS. In order to prevent the intrusion of moisture, dust, and the like in the atmosphere during driving, the hermetic sealing of the vibration chamber 15 must be reliably performed.

FIG. 7 is an enlarged view of the vicinity of the passage 17 in the embodiment of the present invention shown in FIG. FIG. 8 is an enlarged view of the vicinity of the passage 17 of the prototype example when the pitch of the parallelograms of the through holes 13 is set to 200 μm for comparison with FIG. 7 and 8, the hatched portion indicates a portion where the sealing adhesive 30 has entered.

In the electrostatic actuator, in order to make the electrostatic force generated between the diaphragm and the segment electrode (opposite electrode) relatively displaced sufficiently large, the distance (gap length G) between them is set as small as possible. I want to make it narrow. In this embodiment, the depth of the concave portion 16 of the glass substrate 3 is set to 0.3 μm,
The thickness of the segment electrode 18 is set to 0.1 μm. Therefore, the gap length G of the vibration chamber 15 is 0.2 μm.

In order to hermetically seal the electrostatic actuator having such a shape with the sealing adhesive 30, the sealing adhesive 30 is used.
Was infiltrated from the side of the passage 17 open to the atmosphere, and the sealing adhesive 30 was cured. Then, as shown in FIG. 7, the sealing adhesive 30 was able to securely hermetically seal the vibration chamber 15.

On the other hand, the pitch P of the parallelogram of the through hole 13
Was set to 200 μm, and the sealing adhesive 30 was similarly infiltrated and cured to perform hermetic sealing. Then, as shown in FIG. 8, the sealing adhesive 30 did not sufficiently penetrate into the passage 17, and the vibration chamber 15 was not securely hermetically sealed. When this state is observed in more detail, as shown in FIG. 8, the sealing adhesive 30 has taken in bubbles 310 near the discontinuous portion 14 of the through hole 13 of the silicon substrate 2.

In the present embodiment, the sealing adhesive 30 is made of Able Bond 342 manufactured by Able Stick.
37, epoxy-based low-temperature thermosetting type, viscosity 1000c
P-14000 cP is used. The curing of this adhesive proceeds within a range of room temperature (25 ° C.) to 150 ° C. for 48 hours to 2 hours
Curing is completed in time. Epoxy resin has good wettability with silicon and borosilicate glass, and has excellent gas barrier properties against water vapor, so that good hermetic sealing can be achieved. When hermetically sealed with this sealing adhesive, air bubbles were surely penetrated into the passage without taking in bubbles at the discontinuous portions. In addition, the same applies to Able Bond 342-3 manufactured by Able Stick for the sealing adhesive 30.

In this embodiment, the face eject type ink jet head has been described as an example. However, the present invention is not limited to the face eject type ink jet head. For example, the present invention can be applied to an edge-ejection type inkjet head having a nozzle in the length direction of the ink chamber.

(Other Embodiments) The above description is an example in which the present invention is applied to an ink jet head. The present invention can be similarly applied to an electrostatic actuator other than the inkjet head. For example, the present invention can be similarly applied to a micro-mechanical device and a micro-mirror disclosed in Japanese Patent Application Laid-Open No. 7-13007.

[0064]

As described above, in the electrostatic actuator of the present invention, particularly in the ink jet head, the through hole has a planar shape in which continuous parallelograms are overlapped. Thereby, the size of the through hole can be reduced, and an inexpensive electrostatic actuator and ink jet head that can be easily formed can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of an ink jet head to which the present invention is applied.

FIG. 2 is a perspective view of the inkjet head of FIG.

FIG. 3 is an exploded perspective view of the inkjet head of FIG.

FIG. 4 is a plan view of a silicon wafer to which the present invention is applied.

FIG. 5 is a plan view of a silicon wafer showing one example of a conventional example.

FIG. 6 is an explanatory diagram of a mask pattern for forming a through hole of the inkjet head of FIG. 1;

FIG. 7 is an enlarged view of the inkjet head in which the vicinity of the passage in FIG. 1 is enlarged.

FIG. 8 shows a parallelogram overlapping pitch of 200 μm.
FIG. 4 is an enlarged view of the inkjet head in which the vicinity of a passage is enlarged in the case of FIG.

[Explanation of symbols]

 P Pitch of overlapping parallelograms of through-holes 13 1 Ink-jet head 2 Silicon substrate 3 Nozzle plate 4 Glass substrate 5 Ink chamber 6 Common ink chamber 8 Nozzle hole 9 Ink supply path 12 Through-hole of nozzle plate 3 13 Silicon substrate 2 Through hole 14 discontinuous portion of through hole 13 15 vibration chamber 17 passage 18 segment electrode 19 segment electrode wiring portion 20 segment electrode terminal portion 21 voltage applying means 22 common electrode terminal portion 30 sealing adhesive 31 silicon wafer 32 silicon substrate 35 ink chamber 36 common ink chamber 40 ink supply hole 42 common electrode terminal 43 through hole 51 bottom wall of ink chamber (common electrode, diaphragm) 101 silicon wafer 310 bubble

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeo Nojima 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (13)

[Claims] An opening is formed in a polygonal shape in which a plurality of parallelograms continuous on a (110) plane are superimposed, and an opening in which a wiring pattern is arranged is provided thinly on the (110) plane. A (110) silicon substrate having a vibrating plate that conducts to a wiring pattern and is displaced by static electricity; a counter electrode disposed to face the vibrating plate and conductive to a wiring pattern disposed in the opening; A driving unit for applying a voltage from the wiring pattern to the diaphragm and the counter electrode to displace the diaphragm. 2. The electrostatic actuator according to claim 1, wherein a pitch of overlapping the parallelograms of the openings is substantially the same as a pitch of the wiring patterns. 3. The electrostatic actuator according to claim 1, further comprising a sealing member for hermetically sealing a vibration chamber formed by the vibration plate and the counter electrode. 4. The electrostatic actuator according to claim 3, wherein the sealing member is an epoxy-based low-temperature thermosetting type and has a viscosity of 1000 cP to 14000 cP. 5. An opening having a polygonal shape obtained by superimposing a plurality of parallelograms continuous on a (110) plane, and an opening in which a wiring pattern is arranged; A (110) silicon substrate having a vibrating plate that conducts to a wiring pattern and is displaced by static electricity; a counter electrode that is disposed to face the vibrating plate and conducts to a wiring pattern disposed in the opening; A driving means for applying a voltage to the wiring pattern to generate static electricity between the diaphragm and the counter electrode and displacing the diaphragm, and hermetically sealing the gap between the diaphragm and the counter electrode. A sealing member for providing an ink chamber that fluctuates in pressure due to the displacement of the vibration plate; and an ink that communicates with the ink chamber and discharges ink droplets accumulated in the ink chamber due to the fluctuating pressure in the ink chamber. Ink jet head, characterized in that it comprises a nozzle, a. 6. A plurality of wirings, wherein the vibration plate, the ink chamber, and the ink nozzle are formed in a partitioned manner, and a plurality of wirings are provided on the (110) silicon substrate, and are electrically connected to respective counter electrodes of the plurality of vibration plates. The ink jet head according to claim 5, wherein a pattern is arranged in the opening. 7. The ink jet head according to claim 6, wherein a pitch of the parallelogram overlapping the openings is substantially the same as a pitch of the wiring pattern. 8. A (110) silicon substrate having a polygonal opening formed by superposing a plurality of parallelograms continuous on a (110) plane, wherein the parallelogram of the opening is formed. 7. The (110) silicon substrate according to claim 6, wherein an overlapping pitch is equal to or less than a thickness of said (110) silicon substrate. 9. One of the interior angles of the parallelogram is 70.1.
(110) according to claim 8, characterized in that it is 9 degrees.
Silicon substrate. 10. A vertex of a polygon formed by superposing a parallelogram having an inner angle of 70.19 degrees in parallel with its long side, from a vertex having an inner angle of 289.81 degrees to the parallelogram. A mask pattern having a shape obtained by extending the correction pattern in parallel with the long side of the shape (110).
Mask for anisotropic etching of silicon substrate. 11. Among the vertices of a polygon formed by superposing a parallelogram having an inner angle of 70.19 degrees in parallel with its long side, from the vertex having an inner angle of 289.81 degrees to the parallelogram. Masking the (110) plane of the (110) silicon wafer with a mask pattern in which the correction pattern is extended in parallel with the long side of the shape, and anisotropically etching the masked (110) silicon wafer And (11)
0) A method for manufacturing a silicon substrate. 12. The method according to claim 11, wherein the length of the correction pattern is set based on an etch rate of the anisotropic etching. 13. The two types of lengths of the correction pattern of the mask pattern are set based on the etch rates of both surfaces of the (110) silicon wafer, and the two types of mask patterns are used. The (110) according to claim 11, wherein the (110) silicon wafer is anisotropically etched from both sides.
A method for manufacturing a silicon substrate.