JP2010173288A - Silicon-made nozzle substrate, liquid droplet discharge head having silicon-made nozzle substrate, liquid droplet discharge apparatus equipped with liquid droplet discharge head, and method for manufacturing silicon-made nozzle substrate - Google Patents

Abstract

The present invention provides a silicon nozzle substrate that can reduce mechanical stress and prevent chipping or cracking due to rubbing or the like and improve assemblability when it is assembled in alignment with another substrate.
An alignment hole 15 and a track hole 16 are provided for positioning through positioning pins 51 when assembling with other substrates 2 and 3, and these holes 15 and 16 have a cross-sectional area parallel to the substrate surface and a liquid introduction surface. The cross-sectional shape that gradually increases toward the 1b side and is perpendicular to the substrate surface has an exponential curve. At this time, the alignment hole 15 is constituted by a continuous curved surface of a rotating body having a central axis perpendicular to the substrate surface, and the cross-sectional shape including the central axis has an exponential curve that is line symmetric with respect to the central axis. The angle formed between the tangent to the liquid introduction surface 1b on the side wall of the alignment hole 15 and the side wall of the track hole 16 and the perpendicular to the substrate surface is not less than 0 degrees and not more than 10 degrees.
[Selection] Figure 5

Description

  The present invention relates to a silicon nozzle substrate, a droplet discharge head provided with a silicon nozzle substrate, a droplet discharge apparatus equipped with the droplet discharge head, and a method for manufacturing a silicon nozzle substrate.

  Ink jet heads are required to have a structure having a plurality of nozzle arrays for the purpose of increasing the printing speed and colorization. Further, in recent years, the nozzle density has been increased, and the number of nozzles per row has been increased to increase the length, and high precision processing and high durability of the nozzle member are required. For this reason, various devices and proposals have been made regarding the nozzle substrate of the inkjet head.

  Conventionally, the alignment hole and the track hole formed in the nozzle substrate are formed in a circular shape (radius d1) and an elliptical shape (short diameter d1, long diameter d2, d1 <d2). Mechanical stress was reduced (see, for example, Patent Document 1).

JP 2007-144734 A (page 7, FIG. 6)

  In the technique described in Patent Document 1, the vertical cross section of the alignment hole and the track hole is a straight shape, and mechanical stress occurs when inserting the pin into the alignment hole when assembling the nozzle substrate with another substrate. It was.

  The present invention was made in order to solve the above-described problems, and when inserting a positioning pin through an alignment hole and a track hole and aligning and assembling a nozzle substrate with another substrate, mechanical stress is reduced, Silicon nozzle substrate capable of improving assemblability by preventing chipping and cracking due to rubbing, etc., droplet ejection head equipped with silicon nozzle substrate, droplet ejection apparatus equipped with droplet ejection head, and silicon nozzle An object is to provide a method for manufacturing a substrate.

The silicon nozzle substrate according to the present invention includes an alignment hole and a track hole for positioning through positioning pins when assembled with another substrate, and the alignment hole and the track hole have a cross-sectional area parallel to the substrate surface on the liquid discharge surface side. The cross-sectional shape that gradually increases from the surface toward the liquid introduction surface and is perpendicular to the substrate surface has an exponential curve.
Since the positioning pin is passed through the alignment hole and the track hole and the nozzle substrate is aligned with the other substrate and assembled, the contact area between the positioning pin side wall, the alignment hole side wall and the track hole side wall can be reduced. It is possible to improve the yield by preventing chipping and cracking. Further, when the nozzle substrate is passed through the positioning pins, the pins can be smoothly inserted even if the nozzle substrate is slightly inclined, and the working efficiency can be improved.

Further, the silicon nozzle substrate according to the present invention is configured by a continuous curved surface of a rotating body in which the alignment hole has a central axis perpendicular to the substrate surface, and the cross-sectional shape including the central axis is a line with the central axis as a symmetry axis It has a symmetrical exponential curve.
Even if the nozzle substrate is slightly tilted, the positioning pins can be inserted smoothly, and problems such as chipping and cracking peculiar to the silicon member can be eliminated and the yield can be improved.

In the silicon nozzle substrate according to the present invention, the angle formed between the tangent to the liquid introduction surface of the alignment hole side wall and the track hole side wall and the perpendicular to the substrate surface is not less than 0 degrees and not more than 10 degrees.
Since the angle between the tangent and the perpendicular coincides with the allowable tilt amount of the nozzle substrate at the time of assembly, the angle management in the assembly process can be facilitated by setting the angle from 0 degrees to 10 degrees. Further, if the angle is set to be larger than 10 degrees, the accuracy of the alignment hole diameter is lowered, so this range is preferable.

In the silicon nozzle substrate according to the present invention, the cross section of the alignment hole parallel to the substrate surface is a perfect circle, and the cross section of the track hole 16 parallel to the substrate surface is an ellipse. The circle width in the direction perpendicular to the straight line connecting the track hole center and the track hole center is equal to the diameter of the alignment hole, and the circle width in the parallel direction is larger than the diameter of the alignment hole.
Alignment in the direction perpendicular to the straight line requires both an alignment hole and a track hole, but alignment in the parallel direction requires only the alignment hole, so there is room for the track hole dimension in the parallel direction. By doing so, chipping or cracking around the track hole can be reduced.

A droplet discharge head according to the present invention is provided with any of the silicon nozzle substrates described above.
Since the ease of assembly in the pin alignment process is improved, an inexpensive and highly accurate silicon nozzle substrate can be provided.

A droplet discharge apparatus according to the present invention is equipped with the above-described droplet discharge head.
It is possible to provide a droplet discharge device including an inexpensive and highly accurate silicon nozzle substrate.

The method for manufacturing a silicon nozzle substrate according to the present invention includes a step of performing anisotropic dry etching on a base material to form recesses to be alignment holes, track holes, and nozzle holes, respectively, and an oxide film is formed on the base material Performing isotropic dry etching on the alignment hole and track hole recesses of the substrate, removing the oxide film around the inner walls and openings of the recesses serving as the alignment holes and track holes of the substrate, , The step of expanding the side wall of the concave portion into the shape of an exponential curve on the opening side, and the surface opposite to the surface on which the concave portion of the substrate is formed are thinned to penetrate the concave portion, and the alignment hole, track hole and nozzle hole are formed. Forming the process.
Since anisotropic dry etching is employed in the manufacture of alignment holes and the like, it is possible to design alignment holes with a high degree of freedom independent of the crystal orientation of silicon. Moreover, it is only necessary to add isotropic dry etching to the conventional process to expand the side wall into an exponential curve shape, and the increase in manufacturing lead time and cost can be minimized. .

The method for manufacturing a silicon nozzle substrate according to the present invention is characterized in that the angle formed between the tangent at the introduction portion of the alignment hole and the track hole and the perpendicular to the substrate surface is the depth of anisotropic dry etching and the time of isotropic dry etching. It controls by.
Since the amount of diameter expansion in the isotropic dry etching process depends on the distance from the bottom of the vertical hole processed by anisotropic dry etching and the etching time, the amount of diameter expansion is controlled by controlling these two. As a result, the tangential angle at the liquid introduction surface can be controlled.

1 is an exploded perspective view of a droplet discharge head according to Embodiment 1 of the present invention. The longitudinal cross-sectional view of the principal part of the state which assembled FIG. The top view of the nozzle substrate of FIG. II sectional drawing of FIG. FIG. 4 is a cross-sectional view of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate of FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate following FIG. Sectional drawing which shows the manufacturing process of the nozzle substrate following FIG. Sectional drawing which shows the joining process of a cavity board | substrate and an electrode substrate. Sectional drawing which shows the manufacturing process of the joining board following FIG. Sectional drawing which shows the process of joining a nozzle substrate to the joint substrate of a cavity substrate and an electrode substrate. FIG. 6 is a perspective view of an ink jet printer according to a second embodiment of the present invention.

Embodiment 1 FIG.
1 is an exploded perspective view of a droplet discharge head (inkjet head) according to Embodiment 1 of the present invention, FIG. 2 is a longitudinal sectional view of a main part in a state where FIG. 1 is assembled, and FIG. 3 is a nozzle substrate of FIG. 4 is a cross-sectional view taken along the line II in FIG. 3, and FIG. 5 is a cross-sectional view taken along the roll in FIG.
In the figure, an inkjet head 10 includes a nozzle substrate 1 in which a plurality of nozzle holes 11 are provided at predetermined intervals, a cavity substrate 2 in which an ink supply path is provided independently for each nozzle hole 11, and a cavity substrate 2. The electrode substrate 3 provided with the individual electrodes 31 is bonded to the diaphragm 22 and is configured to be bonded.

  The nozzle substrate 1 is made of a silicon base material. The nozzle holes 11 for ejecting ink droplets are two-stage cylindrical nozzle holes having different diameters, that is, a first nozzle hole 11a having a small diameter that opens toward the liquid droplet ejection surface 1a, and a cavity substrate. 2 and a large-diameter second nozzle hole 11b that opens to the liquid introduction surface (bonding surface) 1b side, and is provided perpendicular to the substrate surface and coaxially.

  A first protective film 12 made of a silicon oxide film formed by thermal oxidation is continuously formed from the liquid introduction surface 1 b of the silicon substrate 1 to the inner wall 11 c of the nozzle hole 11. A second protective film 13 made of a silicon oxide film formed by plasma CVD (Chemical Vapor Deposition) is formed from the inner wall 11c of the nozzle hole 11 (on the first protective film 12) to the droplet discharge surface 1a. It is formed continuously. Further, a water repellent film 14 is formed on the second protective film 13 on the droplet discharge surface 1a side.

As shown in FIG. 3, alignment holes 15 and track holes 16 for positioning through positioning pins when assembling with the other substrates 2 and 3 are arranged at the corners in the column direction of the nozzle holes 11 of the nozzle substrate 1. These are formed and constitute so-called tapered holes.
The alignment hole 15 has a circular shape in cross section parallel to the substrate surface, and the track hole 16 has a combined curve in which the cross sectional shape parallel to the substrate surface combines an arc and a straight line. The circular curve of the alignment hole 15 is, for example, a perfect circle, and the compound curve combining the arc and straight line of the track hole 16 is, for example, an ellipse. In this case, assuming that the radius of the perfect circle of the alignment hole 15 is d1, the short circle of the ellipse of the track hole 16 is the same as the radius of the perfect circle of the alignment hole 12, and the major axis is d2, and d1 <d2. There is.
As shown in FIGS. 4 and 5, these holes 15 and 16 have a cross-sectional area gradually increasing from the droplet discharge surface 1a side to the liquid introduction surface 1b side, as shown in FIGS. A cross-sectional shape perpendicular to each other has an exponential curve. In this case, the angle between the tangent to the liquid introduction surface 1b and the perpendicular to the substrate surface is 0 degree or more and 10 degrees or less.

In addition, when the cross-sectional shape parallel to the substrate surface of the alignment hole 15 is a perfect circle, the alignment hole 15 is configured by a continuous curved surface of a rotating body having a central axis perpendicular to the substrate surface, and includes a cross-section including the central axis. The shape has an exponential curve that is symmetric about the central axis.
Thus, when the pin is inserted, the contact area between the positioning pin and the inner wall of the alignment hole 15 and the inner wall of the track hole 16 is reduced, so that problems such as chipping and cracking are avoided, and the positioning pin is smooth even if the nozzle substrate 1 is slightly tilted. Inserted.

  The cavity substrate 2 is made of a silicon base material, and a discharge recess 210, an orifice recess 230, and a reservoir recess 240 are formed. The discharge recess 210 (discharge chamber 21) and the reservoir recess 240 (reservoir 24) communicate with each other through the orifice recess 230 (orifice 23). The reservoir 24 constitutes a common ink chamber common to the discharge chambers 21 and communicates with the discharge chambers 21 via the orifices 23. An ink supply hole 25 penetrating an electrode substrate 3 described later is formed at the bottom of the reservoir 24, and ink is supplied from an ink cartridge (not shown). The bottom wall of the discharge chamber 21 is a diaphragm 22. An insulating silicon oxide film 26 is formed on at least the surface of the cavity substrate 2 facing the electrode substrate 3 by thermal oxidation or plasma CVD to prevent dielectric breakdown or short circuit when the inkjet head 10 is driven. To do.

  The electrode substrate 3 is made from a glass base material. The electrode substrate 3 is provided with a recess at a position facing the diaphragm 22 of the cavity substrate 2. In each recess, individual electrodes 31 made of ITO (Indium Tin Oxide) are formed by sputtering. The individual electrode 31 includes a lead portion 31a and a terminal portion 31b connected to a flexible wiring board (not shown). The terminal portion 31b has an end portion of the cavity substrate 2 opened for wiring. It is exposed in the electrode extraction part 41. The terminal portions 31b of the individual electrodes 31 and the common electrode 27 on the cavity substrate 2 are connected via a drive control circuit 40 such as an IC driver. The open end of the gap G formed between the diaphragm 22 and the individual electrode 31 is sealed with a sealant 42 made of a resin such as epoxy.

Next, the operation of the inkjet head 10 configured as described above will be described.
When the drive control circuit 40 is driven and charges are supplied to the individual electrodes 31 to charge them positively, the diaphragm 22 is negatively charged and an electrostatic attractive force is generated between the individual electrodes 31 and the diaphragm 22. . Due to the electrostatic attractive force, the diaphragm 22 is attracted to the individual electrode 31 and bent. As a result, the volume of the discharge chamber 21 increases. When the supply of electric charges to the individual electrode 31 is stopped, the electrostatic attractive force disappears, and the vibration plate 22 returns to its original state due to its elastic force. At this time, the volume of the discharge chamber 21 decreases rapidly, and the pressure at that time causes Part of the ink in the discharge chamber 21 is discharged from the nozzle hole 11 as an ink droplet. Next, when the vibration plate 22 is similarly displaced, ink is supplied from the reservoir 24 through the orifice 23 into the discharge chamber 21.

  A method for manufacturing the inkjet head 10 configured as described above will be described with reference to FIGS. 6 to 8 are cross-sectional views illustrating the manufacturing process of the nozzle substrate 1, FIGS. 9 to 10 are cross-sectional views illustrating the bonding process of the cavity substrate 2 and the electrode substrate 3, and FIG. 11 is a cross-sectional view illustrating the bonding process of the nozzle substrate. FIG. In addition, the numerical value described in the following description shows the example, and is not limited to this.

First, the manufacturing process of the nozzle substrate 1 will be described with reference to FIGS.
(A) As shown in FIG. 6A, a thermal oxide film 101 of 0.5 μm is formed on the surface of a single crystal silicon substrate 100 (nozzle substrate 1) having a thickness of 725 μm, and a liquid introduction surface (adhesion surface). On the 1b side, the second nozzle hole pattern 102, the alignment hole pattern 103, the track hole pattern (not shown), and the chip outer edge pattern 104 are opened.

(B) As shown in FIG. 6B, a resist film 105 having a thickness of 1.0 μm is formed on the liquid introduction surface 1b side, and the first nozzle hole pattern 106, the alignment hole pattern 107, and the like are formed by photolithography. A track hole pattern (not shown) and a chip outer edge pattern 108 are opened.

(C) As shown in FIG.6 (c), by anisotropic dry etching, the 1st nozzle hole (the recessed part used as the 1st nozzle hole) 11a, the alignment hole (the recessed part used as the alignment hole) 15, The track holes (recesses to be track holes, not shown) and the chip outer edge (portion to be the chip outer edge) 17 are etched to a depth of 40 μm.

(D) As shown in FIG. 6D, after removing the resist film 105, the second nozzle hole (recessed portion serving as the second nozzle hole) 11b is etched to a depth of 40 μm by anisotropic dry etching. To do. At this time, the first nozzle hole 11a, the alignment hole 15, the track hole (not shown) 16, and the chip outer edge (portion serving as the chip outer edge) 17 are also etched to a depth of about 70 to 80 μm. .

(E) As shown in FIG. 7E, after the oxide film 101 is peeled off, a first protective film (silicon oxide film) 12 having a thickness of 0.2 μm is formed by thermal oxidation. The protective film 12 also serves as a mask in an isotropic dry etching process described later.

(F) As shown in FIG. 7F, the tape 109 protects the periphery of the alignment hole 15, the periphery of the track hole (not shown), and the periphery of the chip outer edge 17, and the alignment hole 15, the track hole, The oxide film 12 on the chip outer edge 17 is removed with hydrofluoric acid.

(G) As shown in FIG. 7G, the tape 109 is removed, and the alignment holes 15, the track holes, and the side walls of the chip outer edge 17 are processed into a tapered shape by isotropic dry etching.

(H) As shown in FIG. 7 (h), the support substrate 110 is bonded to the liquid introduction surface 1b, and a thinning process is performed from the surface on the liquid discharge side. The nozzle hole 11, the alignment hole 15, the track hole, The chip outer edge 17 is penetrated.

(I) As shown in FIG. 8 (i), a second protective film (silicon oxide film) 13 made of TEOS (TetraEthylOrthosilicate) is formed to 0.1 μm on the thinned discharge surface 1a by plasma CVD.

(J) As shown in FIG. 8J, a silane coupling material is dip coated to form a water repellent film 14 on the ejection surface 1a. At this time, the water repellent film 14 is also formed on the inner wall of the nozzle hole 11.

(K) As shown in FIG. 8 (k), a support tape 111 is attached to the discharge surface 1a, the support substrate 110 on the liquid introduction surface 1b is peeled off, and oxygen or argon plasma treatment is performed from the adhesive surface 1b side. The water-repellent film 14 on the inner wall of the nozzle hole 11 is broken to become hydrophilic.

(L) As shown in FIG. 8 (l), the support tape 111 is peeled off.
The nozzle substrate 1 is manufactured from the silicon base material 100 through the above steps.

Next, the bonding process of the cavity substrate 2 and the electrode substrate 3 will be described with reference to FIGS.
(A) As shown in FIG. 9A, a glass substrate 300 (electrode substrate) made of borosilicate glass or the like is etched with hydrofluoric acid using an etching mask to form a plurality of groove-shaped recesses 310. . Next, the electrode 31 is formed in the recess 310 by sputtering ITO and patterning by photolithography. Thereafter, the ink supply holes 25 are formed by sandblasting or the like.

(B) After mirror-polishing one surface of the silicon substrate 200, as shown in FIG. 9B, the silicon oxide film 201 (insulating film 26, FIG. h)). Note that before the silicon oxide film 201 is formed, a boron doped layer for etching stop may be formed. By forming the diaphragm from the boron-doped layer, a diaphragm with high thickness accuracy can be formed.

(C) As shown in FIG. 9 (c), the silicon substrate 200 shown in FIG. 9 (b) and the glass substrate 300 shown in FIG. 9 (a) are heated to 360 ° C. A cathode is connected to the anode and the glass substrate 300, and a voltage of about 800 V is applied to perform anodic bonding.

(D) After anodic bonding of the silicon substrate 200 and the glass substrate 300, the bonded substrate obtained in the step of FIG. 9 (c) is etched with an aqueous potassium hydroxide solution or the like, as shown in FIG. 9 (d). Then, the entire silicon substrate 200 is thinned.

(E) A TEOS film 201 is formed on the entire upper surface of the silicon substrate 200 (the surface opposite to the surface to which the glass substrate 300 is bonded) by plasma CVD.
Then, the TEOS film 201 is patterned by photolithography in the recess 210 serving as the discharge chamber 21, the recess 240 serving as the reservoir 24, and the recess 230 serving as the orifice 23.
Thereafter, as shown in FIG. 10E, the silicon substrate 200 is etched with a potassium hydroxide aqueous solution or the like using the TEOS film 201 as a mask, so that a recess 210 serving as the discharge chamber 21, a recess 240 serving as the reservoir 24, and an orifice 23 are obtained. A recess 230 is formed. At this time, the portion 41a that becomes the electrode lead-out portion 41 (see FIG. 10H) is also etched and thinned. In the wet etching step shown in FIG. 10E, a 35% by weight potassium hydroxide aqueous solution is used first, and then a 3% by weight potassium hydroxide aqueous solution is used. Thereby, surface roughness of the diaphragm 22 is suppressed.

(F) After the etching of the silicon substrate 200 is completed, the bonded substrate is etched with a hydrofluoric acid aqueous solution, and the TEOS film 201 formed on the silicon substrate 200 is removed as shown in FIG.

(G) As shown in FIG. 10G, a protective film 202 made of TEOS or the like is formed by CVD on the surface of the silicon substrate 200 on which the recesses 210 to be the discharge chambers 21 are formed.

(H) As shown in FIG. 11 (h), the electrode extraction part 41 is opened by RIE (Reactive Ion Etching) or the like. In addition, the silicon substrate 200 is machined or laser processed to penetrate the ink supply holes 25 through the recesses 240 serving as the reservoirs 24. Thus, a bonded substrate (actuator substrate) in which the cavity substrate 2 and the electrode substrate 3 are bonded is completed.
A sealant 42 for sealing the space between the diaphragm 22 and the individual electrode 31 is applied to the electrode extraction portion 41.

Next, a process of bonding the nozzle substrate 1 to the bonding substrate of the cavity substrate 2 and the electrode substrate 3 will be described with reference to FIG.
(A) As shown in FIG. 11A, the pin holes 15 a and 16 a of the bonding substrate between the cavity substrate 2 and the electrode substrate 3 are set through the positioning pins 51 of the jig 50.

(B) As shown in FIG. 11 (b), an adhesive is applied to the liquid introduction surface 1 b of the nozzle substrate 1, and the alignment holes 15 and the track holes 16 of the nozzle substrate 1 are passed through the positioning pins 51 of the jig 50. Then, the cavity substrate 2 and the electrode substrate 3 are laminated on the bonding substrate.

(C) As shown in FIG. 11 (c), the nozzle substrate 1 is bonded to the bonding substrate of the cavity substrate 2 and the electrode substrate 3 by applying pressure and heating.
By passing through the above manufacturing process, the joined body of the nozzle substrate 1, the cavity substrate 2 and the electrode substrate 3 is completed.
Finally, the bonded substrate to which the cavity substrate 2, the electrode substrate 3, and the nozzle substrate 4 are bonded is separated by dicing to complete the inkjet head 10 (see FIG. 2).

  According to the present invention, since the alignment hole 15 and the track hole 16 are tapered holes in the process of aligning and assembling the nozzle substrate 1 with the other members 2 and 3, the alignment hole 15 and the track hole 16 are positioned. When passing through the pin 51, the contact area between the side wall of the positioning pin 51, the side wall of the alignment hole 15, and the side wall of the track hole 16 can be reduced, and the yield is avoided by avoiding problems such as chipping and cracking due to rubbing. Can be improved. Further, when the nozzle substrate 1 is passed through the positioning pins 51, the positioning pins 51 can be smoothly inserted even if the nozzle substrate 1 is slightly inclined, so that the assembling property can be improved and the working efficiency can be improved.

  The cross section of the alignment hole 15 parallel to the substrate surface is, for example, a perfect circle, and the cross section of the track hole 16 parallel to the substrate surface is, for example, an ellipse. The ellipse connects the alignment hole center and the track hole center. If the circular width in the direction perpendicular to the straight line is equal to the diameter of the alignment hole and the circular width in the parallel direction is larger than the diameter of the alignment hole, the track hole size in the alignment in the direction parallel to the straight line Therefore, chipping or cracking around the track hole can be reduced.

  Further, since the angle formed between the tangent to the liquid introduction surface 1b and the perpendicular to the substrate surface matches the allowable tilt amount of the nozzle substrate 1 at the time of assembly, the angle management in the assembly process can be performed by setting it from 0 degrees to 10 degrees. Has the effect of facilitating If the angle is larger than 10 degrees, the accuracy of the diameters of the alignment hole 15 and the track hole 16 is lowered.

  In addition, the alignment hole 15 and the track hole 16 are anisotropically dry etched simultaneously with the nozzle hole 11 and then formed into a tapered shape by isotropic dry etching, so that they depend on the silicon crystal direction by anisotropic dry etching. It is possible to design alignment holes with a high degree of freedom. Furthermore, it is only necessary to add isotropic dry etching to the conventional process to expand the side wall into an exponential curve shape, thereby minimizing an increase in manufacturing lead time and cost.

  In addition, since the amount of diameter expansion in the isotropic dry etching process depends on the distance from the bottom surface of the vertical hole processed by anisotropic dry etching and the etching time, the amount of diameter expansion can be controlled by controlling these two. Thus, the tangential angle at the liquid introduction surface 1b can be controlled.

Embodiment 2. FIG.
FIG. 12 is a perspective view of a droplet discharge device (inkjet printer) according to Embodiment 2 of the present invention. In the inkjet head 10 obtained in the first embodiment, the assembly alignment hole 15 and the track hole 16 are formed in a tapered shape to improve the assemblability in the pin alignment process, and thus the inkjet head 10 is used. Thus, an inexpensive and highly accurate ink jet printer as shown in FIG. 12 can be obtained.
The ink jet head 10 according to the first embodiment is an example of a liquid droplet ejection head, and the liquid droplet ejection head is not limited to the ink jet head 10, and the color of the liquid crystal display can be changed by variously changing the liquid droplets. The present invention can also be applied to the manufacture of filters, the formation of light emitting portions of organic EL display devices, the discharge of biological liquids, and the like.

  DESCRIPTION OF SYMBOLS 1 Nozzle substrate, 1a Droplet discharge surface, 1b Liquid introduction surface, 2 Cavity substrate, 3 Electrode substrate, 10 Inkjet head, 11 Nozzle hole, 11a 1st nozzle hole, 11b 2nd nozzle hole, 11c Inner wall of nozzle hole , 12 First protective film (silicon oxide film), 13 Second protective film (silicon oxide film), 14 Water repellent film, 15 Alignment hole, 16 Track hole, 51 Positioning pin, 100 Silicon substrate.

Claims (8)

Alignment holes and track holes for alignment through positioning pins when assembled with other substrates,
The alignment hole and the track hole gradually increase in cross-sectional area parallel to the substrate surface from the liquid discharge surface side toward the liquid introduction surface side,
A cross-sectional shape perpendicular to the substrate surface has an exponential curve;
A silicon nozzle substrate characterized by that.   The alignment hole is composed of a continuous curved surface of a rotating body having a central axis perpendicular to the substrate surface, and the cross-sectional shape including the central axis has an exponential curve that is line symmetric with respect to the central axis. The silicon nozzle substrate according to claim 1.   3. The silicon nozzle substrate according to claim 1, wherein an angle formed between a tangent to the liquid introduction surface of the alignment hole side wall and the track hole side wall and a perpendicular to the substrate surface is 0 ° to 10 °. .   The cross section of the alignment hole parallel to the substrate surface is a perfect circle, the cross section of the track hole parallel to the substrate surface is an ellipse, and the ellipse is perpendicular to a straight line connecting the alignment hole center and the track hole center. The silicon nozzle substrate according to claim 1, wherein a circular width in a direction is equal to a diameter of the alignment hole, and a circular width in a parallel direction is larger than a diameter of the alignment hole.   A droplet discharge head comprising the silicon nozzle substrate according to claim 1.   A droplet discharge apparatus comprising the droplet discharge head according to claim 5. Performing anisotropic dry etching on the substrate to form recesses to be alignment holes, track holes, and nozzle holes, respectively;
Forming an oxide film on the substrate;
Removing the oxide film around the inner wall and the opening of the concave portion to be the alignment hole and the track hole of the substrate;
Performing isotropic dry etching on the recesses to be the alignment holes and track holes of the base material, and expanding the side walls of the recesses into an exponential curve shape on the opening side;
Forming the alignment hole, the track hole, and the nozzle hole by thinning the surface on the opposite side of the surface on which the concave portion of the substrate is formed and penetrating the concave portion;
A method for producing a silicon nozzle substrate, comprising:   8. The angle formed between a tangent line at the introduction portion of the alignment hole and the track hole and a perpendicular to the substrate surface is controlled by the depth of anisotropic dry etching and the time of isotropic dry etching. The manufacturing method of the nozzle board | substrate made from silicon of description.

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