JP2006205572A - Manufacturing method for three-dimensional hollow structure, and manufacturing method for liquid ejection head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a three-dimensional structure, which enables a shape of a hollow area to be arbitrarily designed. <P>SOLUTION: This method for manufacturing the three-dimensional hollow structure comprises at least a step of partially forming a porous area in a silicon substrate, a step of forming a silicon layer on the substrate forming the porous area and of partially forming the porous area in the silicon layer, and a step of forming a hollow area by removing the porous area by etching. The method for manufacturing the three-dimensional hollow structure is used for the manufacture of the an ejection head of an inkjet recording apparatus with good positional accuracy, excellent in heat resistance and durability by virtue of the absence of a joint. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for processing a silicon (hereinafter referred to as “Si”) substrate that can be applied to a semiconductor element, a light-transmitting substrate, a microelectromechanical mechanism, and the like, in particular, a Si having a hollow region in which a three-dimensional shape can be arbitrarily designed. The present invention relates to a method for producing a three-dimensional hollow structure.

  In addition, the present invention relates to a method for manufacturing a liquid discharge head (hereinafter referred to as “discharge head”) of an ink jet recording apparatus, and a method for manufacturing a discharge head that is compatible with various discharge methods. The present invention relates to a method for manufacturing a discharge head that has no joint portion and is manufactured using an integrated substrate of Si material.

  As the Si substrate, a Si substrate having an unsupported thin layer structure without a support directly underneath has been proposed, and as a processing method thereof, a porous material is partially formed on the surface or back surface of non-porous Si. Then, a method has been proposed in which a void is formed by forming a porous layer from the front surface to the back surface, forming a thin layer before and after that, and then removing the porous material by etching. In addition, as a method of partially forming a porous structure, a method of partially covering with a mask and making the exposed portion porous is proposed, and a method of partially increasing the resistance and making the exposed low resistance portion porous. (See Patent Document 1 below).

  FIG. 18 is a diagram showing a Si substrate and a processing method thereof in Patent Document 1.

  In FIG. 18, the front and back surfaces of the non-porous Si are partially covered with a mask, the exposed portion is made porous from the front surface to the back surface, and then acts as a thin layer and can finally become an unsupported thin layer. Forming.

  That is, the front and back surfaces of the non-porous Si substrate 201 are covered with the mask 202, and a window is partially opened ((a)). Here, a polyimide film, apizone wax, a high-resistance epitaxial film, a high-resistance non-epitaxial deposition film, or the like that is highly resistant to hydrofluoric acid is used as the mask. Next, the exposed portion is made porous from the front surface to the back surface to form a porous Si region 203 ((b)). Thereafter, the mask 12 is peeled off ((c)), and a thin layer 204 that can finally become an unsupported thin layer is formed on either side ((d)). Next, the porous Si region 203 is removed by chemical etching ((e)). In this way, it is possible to make a hole by leaving the non-porous Si substrate 201 partially in one or more places, leaving a thin layer 204 without a support directly on one side.

  On the other hand, in recent years, printers using an ink jet recording apparatus as a printing apparatus such as a personal computer are widely used for reasons such as good printing performance, easy handling, and low cost. In this ink jet recording apparatus, a bubble is generated in a recording liquid such as ink by thermal energy, and a droplet is discharged by a pressure wave due to the bubble, a droplet is discharged by an electrostatic force, a piezoelectric element, etc. There are various methods such as a method of ejecting droplets using pressure waves generated by a vibrator.

In general, a device using a piezoelectric element includes, for example, an individual liquid chamber that communicates with a common liquid chamber via a liquid supply path, and a discharge port that communicates with the individual liquid chamber. There is a d _31- mode ejection head that is provided with the above-described diaphragm. In such a configuration, by applying a predetermined voltage to the piezoelectric element and expanding and contracting the piezoelectric element, the recording liquid in the pressure chamber is compressed by causing a bending displacement to discharge the droplet from the discharge port. Further, there are a piston mode ejection head that utilizes displacement in the thickness direction of the piezoelectric film as the d ₃₃ mode or the d ₃₁ mode, and a piezoelectric ejection head that utilizes a d ₁₅ mode known as a shear mode.

  In addition, as a method using thermal energy, a discharge port, an individual liquid chamber, a liquid supply path, and the like are formed on a substrate having a resistor serving as a heating element, and bubbles are generated in the individual liquid chamber to discharge the liquid. is there.

  Further, the method using electrostatic force is a method in which a diaphragm is displaced by electrostatic force to discharge a liquid.

As a manufacturing method of such an ejection head of an ink jet recording apparatus, a method in which two substrates are bonded is known (see Patent Documents 2 and 3 below).
JP-A-5-90113 JP 2004-42397 A JP 2000-326516 A JP 2001-63865 A

  However, in the structure manufactured by the Si substrate manufacturing method in Patent Document 1, the shape of the hole to be formed cannot be designed freely, and it is only one part satisfying each single function. Therefore, in order to function as a product, it is necessary to combine it with many other parts, and there is a risk that the assembly accuracy will be reduced. In addition, there is a concern that miniaturization is difficult and the product becomes large.

On the other hand, in the conventional liquid discharge heads of the ink jet recording apparatus, any of the discharge heads is made of a material such as Si, SiO ₂ , SUS, or photosensitive material as a material constituting the discharge port, the individual liquid chamber, the liquid supply path, and the like. They are used, and are produced by a film forming process, bonding, adhesion, or the like.

In addition, Si substrates are mainly used for semiconductor processes, but the resulting ejection head has problems in durability and dimensional accuracy because different materials from Si occupy a part of the constituent materials. Met. For example, in the method using an adhesive, there has been proposed a method of preparing a liquid pool in the substrate so that the adhesive does not enter the individual liquid chamber. In addition, due to dimensional errors due to variations in the thickness of the adhesive layer, there are problems with variations in the discharge characteristics of the liquid from each discharge port, and when the discharge head itself is long, it is a discharge head joined with a different material. In this case, there is a problem that stress is applied due to an environmental change after a long period of use, the element itself bends, the discharge performance changes, and the discharge failure occurs due to film peeling. In addition, since the ejection head in the d ₃₁ flexure mode uses a rigid diaphragm, if a dissimilar material layer is included in the casing and the diaphragm, element warpage, separation of the diaphragm, and generation of cracks may occur. I was scared.

  Accordingly, a first object of the present invention is to form a hollow region of an arbitrary shape in a Si base, thereby selectively and finely processing it into a structure having a composite function. Another object of the present invention is to provide a method for producing a three-dimensional hollow structure made of Si that can be applied to a microelectromechanical mechanism or the like.

  A second object of the present invention is to provide a method for manufacturing a discharge head that is substantially free of joints and in which a casing is integrally formed. It is another object of the present invention to provide a method for manufacturing an ejection head that is free from problems such as film peeling and peeling due to a difference in coefficient of thermal expansion and has high positional accuracy.

  In order to solve the above-described problems, a method for producing a three-dimensional hollow structure according to the present invention includes a step of partially forming a porous region in a Si substrate, and forming a Si layer on the substrate on which the porous region is formed. And at least a step of forming a porous region in the Si layer and a step of etching away the porous region to form a hollow region.

  The method for producing a three-dimensional hollow structure of the present invention includes a step of partially forming a high concentration impurity region in a Si substrate, forming a Si layer on the substrate on which the high concentration impurity region is formed, At least a step of forming a high concentration impurity region in the layer, a step of forming a porous region in the high concentration impurity region, and a step of etching away the porous region to form a hollow region. Features.

  Furthermore, in the method for manufacturing a liquid discharge head according to the present invention, a step of forming a porous portion partially in a Si substrate, a Si layer is formed on the substrate, and a porous portion is partially formed in the Si layer. A step of forming, a step of forming a liquid discharge source, and a step of forming at least an individual liquid chamber and a liquid supply path communicating with the individual liquid chamber by removing the porous portion.

  According to the method for producing a three-dimensional hollow structure of the present invention, the shape of the hollow region can be arbitrarily designed in the Si substrate.

  Further, according to the method for manufacturing a liquid discharge head of the present invention, at least the liquid supply path and the individual liquid chamber that receives the pressure of the liquid are made of Si material, and there are no joints in the constituent members, and they are integrally formed. By manufacturing a discharge head, it is possible to manufacture a discharge head that is excellent in heat resistance, durability, and positional accuracy without problems such as film peeling and peeling due to a difference in thermal expansion coefficient.

  Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The first embodiment is an example in which a porous region in non-porous Si is removed to form a hollow region, and the second embodiment is a method in which an impurity region in non-porous Si is removed to form a hollow region. In the third embodiment, the Si integrated three-dimensional hollow structure manufacturing method in the first and second embodiments is applied to a printer discharge head manufacturing method.

[First embodiment]
Hereinafter, a method for producing a three-dimensional hollow structure according to a preferred first embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view schematically showing a method for producing a three-dimensional hollow structure according to a preferred first embodiment of the present invention.

  First, in the step shown in FIG. 1A, the surface of the non-porous Si 11 is covered with a mask 12 and a window is partially opened. Here, as the mask material, a polyimide film, an apizone wax, a nitride film, or the like that is highly resistant to hydrofluoric acid is suitable.

  Next, in the step shown in FIG. 1B, the porous region 13 is formed in the exposed portion of the nonporous Si11. The porous region 13 can be formed, for example, by performing anodizing treatment (anodic treatment) in an electrolytic solution (chemical conversion solution). Here, as the electrolytic solution, for example, a solution containing hydrogen fluoride, a solution containing hydrogen fluoride and ethanol, a solution containing hydrogen fluoride and isopropyl alcohol, and the like are suitable. The porous region 13 may have a multilayer structure including two or more layers having different porosities. Here, the porous region 13 having a multilayer structure includes a first porous Si layer having a first porosity on the surface side, and a second porosity having a second porosity larger than the first porosity below the first porous Si layer. It is preferable that the porous Si layer is included. Here, the first porosity is preferably 10% to 30%, and more preferably 15% to 25%. The second porosity is preferably 10% to 70%. The formation of the porous region 13 may be performed by another method, such as stain etching, instead of anodizing.

  Next, in the step shown in FIG. 1C, the mask 12 is peeled off to form a structure in which one layer of the porous region 13 is disposed.

  Next, in the step shown in FIG. 1D, a non-porous Si layer 14 is formed on the substrate of FIG. 1C in which the porous region 13 is partially arranged. There is no problem even if the non-porous Si layer 14 is a Si layer such as a single crystal Si layer, a polycrystalline Si layer, or an amorphous Si layer. Further, the surface of the non-porous Si layer 14 is covered with a mask 12 to partially open a window.

  Next, in the step shown in FIG. 1 (e), the porous region 13 is formed in the exposed portion of the non-porous Si layer 14.

  Next, in the step shown in FIG. 1F, the mask 12 is peeled off, and a structure in which the porous region 13 is partially arranged in two layers is formed.

  Next, in the steps shown in FIGS. 1 (g) to (h), the steps shown in FIGS. 1 (d) to (e) are repeated in the same manner, and the three-dimensional hollow in which the porous regions 13 are partially arranged in multiple layers. A structure is formed.

  Next, in the step shown in FIG. 1 (i), the mask 12 is peeled off, and only the porous region 13 is selectively removed by etching to form a three-dimensional hollow structure in which the hollow regions 15 are partially multilayered. The

  Here, the operation will be described. Since the porous Si used in the present invention is formed along the flow of current during anodization, the flow of current is controlled by providing a mask or impurity concentration distribution. It is possible to process non-porous Si in almost any shape and porosity. In addition, since a large amount of voids are formed inside the porous Si, the surface area increases dramatically compared to the volume. As a result, chemical etching can be performed at a significantly higher rate than non-porous Si, and a three-dimensional porous structure and a three-dimensional hollow structure can be produced with high accuracy and fineness.

  Furthermore, if the hollow region 15 is joined in multiple layers in the depth direction by the above processing method, a space of an arbitrary shape can be obtained. In addition, it is possible to manufacture a Si substrate having a hollow region having a structure and properties adapted to a design satisfying each function such as a semiconductor element, a light-transmitting substrate, and a micro electro mechanical mechanism.

  Hereinafter, although this embodiment is described based on an Example, this invention is not limited to this Example.

[Example 1]
A method for producing a three-dimensional hollow structure according to an embodiment of the present invention is shown in FIG. This example corresponds to the first embodiment.

  First, a P-type (100) specific resistance 0.01 Ωcm Si substrate was used as non-porous Si11, and a 1 μm polyimide film was applied as a mask 12 on the Si substrate. Thereafter, a window for forming a porous region was opened by photolithography (FIG. 1A).

Next, anodization was performed on a partially opened Si substrate. Anodization was carried out for 14 minutes at a current density of 10 mA / cm ² in a solution in which a 49% hydrofluoric acid solution and an alcohol solution were mixed at a ratio of 1: 1. The thickness of the porous Si layer 13 was 15 μm (FIG. 1B).

  Next, the mask 12 was peeled off to form a Si substrate in which the porous region 13 was partially disposed in one layer (FIG. 1C).

  Next, heat treatment was performed at 400 ° C. for 60 minutes in an oxygen atmosphere to stabilize the surface of the porous Si layer 13. Thereafter, Si was epitaxially grown on the Si substrate on which the porous region 13 was partially arranged, thereby forming an epitaxial Si layer 14 having a thickness of 10 μm.

  Next, a 1 μm polyimide film was applied and formed as a mask 12 on the epitaxial Si layer 14. Thereafter, a window for forming a porous region was opened by photolithography (FIG. 1D).

Next, anodization was performed on the epitaxial Si layer 14 partially opened. Anodization was carried out for 9 minutes at a current density of 10 mA / cm ² in a solution in which a 49% hydrofluoric acid solution and an alcohol solution were mixed at a ratio of 1: 1. The thickness of the porous Si layer 13 was 10 μm (FIG. 1E).

  Next, the mask 12 was peeled off to form a Si substrate in which the porous region 13 was partially disposed in two layers (FIG. 1 (f)).

  Next, heat treatment was performed at 400 ° C. for 60 minutes in an oxygen atmosphere to stabilize the surface of the porous Si layer 13. Thereafter, Si was epitaxially grown on the Si substrate on which the porous region 13 was partially disposed, thereby forming an epitaxial Si layer 14 having a thickness of 5 μm.

  Next, a 1 μm polyimide film was applied and formed as a mask 12 on the epitaxial Si layer 14. Thereafter, a window for forming a porous region was opened by photolithography (FIG. 1 (g)).

Next, anodization was performed on the epitaxial Si layer 14 partially opened. Anodization was carried out at a current density of 10 mA / cm ² for 4 minutes in a solution in which a 49% hydrofluoric acid solution and an alcohol solution were mixed at a ratio of 1: 1. The thickness of the porous Si layer 13 was 5 μm (FIG. 1 (h)).

Next, the mask 12 was peeled off, the substrate was immersed in a hydrofluoric acid: hydrogen peroxide: water = 2: 8: 90 solution for 90 minutes, and the porous region 13 was removed by etching. A three-dimensional hollow structure Si substrate in which the hollow regions 15 are partially arranged in multiple layers was formed (FIG. 1 (i)).
[Second Embodiment]
Hereinafter, a method for manufacturing a substrate according to a preferred second embodiment of the present invention will be described.

  FIG. 2 is a conceptual diagram showing a method for manufacturing a substrate according to a preferred second embodiment of the present invention.

  First, in the step shown in FIG. 2A, the surface of the non-porous Si 21 is covered with a mask 22 and a window is partially opened. Here, as the non-porous Si, a high-resistance N-type substrate is suitable, and as the mask 22, a photoresist film, a nitride film, or the like is suitable as a protective film for ion implantation.

  Next, in the step shown in FIG. 2B, an impurity region 23 is formed in the exposed portion of the non-porous Si 21. Here, the impurity region 23 is desirably formed at a high concentration by ion implantation of As and B.

  Next, in the step shown in FIG. 2C, the mask 22 is peeled off, and a structure in which one impurity layer 23 is partially disposed is formed.

  2D, a non-porous Si layer 24 is formed on the substrate of FIG. 2C in which the impurity region 23 is partially arranged. Here, since the non-porous Si layer 24 is formed on the non-porous Si 21, it can be easily and accurately formed by conventional techniques. Further, the surface of the non-porous Si layer 24 is covered with a mask 22 to partially open a window.

  Next, in the step shown in FIG. 2E, an impurity region 23 is formed in the exposed portion of the non-porous Si layer 24. Here, the impurity region 23 is desirably formed at a high concentration by ion implantation of As and B.

  Next, the steps shown in FIGS. 2C to 2E are repeated in the same manner, and in the step shown in FIG. 2F, heat treatment is performed so that the impurity regions 23 are bonded by diffusion, and the impurity regions 23 are partially formed. A three-dimensional hollow structure having a multi-layer arrangement is formed.

  Next, in the step shown in FIG. 2G, the porous region 25 is formed in the portion where the impurity region 23 is formed in the non-porous Si 21. The porous region 25 can form the impurity region 23 along the concentration distribution by, for example, performing anodizing treatment (anodic treatment) in an electrolytic solution (chemical conversion solution). Here, as the electrolytic solution, for example, a solution containing hydrogen fluoride, a solution containing hydrogen fluoride and ethanol, a solution containing hydrogen fluoride and isopropyl alcohol, and the like are suitable. The porous region 25 may have a multilayer structure including two or more layers having different porosities. The formation of the porous region 25 may be performed by another method such as stain etching instead of anodizing.

  Next, in the step shown in FIG. 2 (h), the mask 22 is peeled off, and only the porous region 25 is selectively removed by etching to form a three-dimensional hollow structure in which the hollow regions 26 are partially arranged in multiple layers. .

  Hereinafter, although this embodiment is described based on an Example, this invention is not limited to this Example.

[Example 2]
A method for manufacturing a substrate according to an embodiment of the present invention is shown in FIG. This example corresponds to the substrate manufacturing method according to the second embodiment.

  First, an N-type (100) specific resistance 5 Ωcm Si substrate was used as the non-porous Si 21, and a 1 μm photoresist film was applied and formed as a mask 22 on the Si substrate. Thereafter, a window was formed in the portion where the impurity region was formed by photolithography (FIG. 2A).

Next, As and B ions were implanted into the surface of the Si substrate partially opened. Ion implantation was performed at an As concentration of 6E19 atms / cm ³ and a B concentration of 6E18 atms / cm ³ . (FIG. 2 (b)).

  Next, the mask 22 was peeled off to form a Si substrate in which the impurity region 23 was partially disposed in one layer (FIG. 2C).

  Next, Si was epitaxially grown on the Si substrate in which the impurity region 23 was partially disposed, thereby forming an epitaxial Si layer 24 having a thickness of 0.3 μm.

  Next, a 1 μm photoresist film was applied as a mask 22 on the epitaxial Si layer 24 to form a film. Thereafter, a window was formed in the portion where the impurity region was formed by photolithography (FIG. 2D).

Next, As and B ions were implanted into the surface of the epitaxial Si layer 24 partially opened. Ion implantation was performed at an As concentration of 6E19 atms / cm ³ and a B concentration of 6E18 atms / cm ³ . (FIG. 2 (e)).

  Next, the steps shown in FIGS. 2C to 2E were repeated in the same manner. At this time, a nitride film was formed as the mask 22 by LPCVD. Thereafter, heat treatment was performed at 1000 ° C. for 30 minutes in a nitrogen atmosphere so that the impurity regions 23 were bonded by diffusion, thereby forming a Si substrate in which the impurity regions 23 were partially arranged in layers (FIG. 2F).

Next, anodization was performed on the impurity region 23 partially opened. Anodization is performed in a solution in which a 49% hydrofluoric acid solution, an alcohol solution, and water are mixed at a ratio of 2: 1: 7, first at a current density of 4 mA / cm ² for 90 seconds, and then at a current density of 43 mA / cm. ² for 9 seconds, followed by a current density of 170 mA / cm ² for 6 seconds. A porous region 25 having a different porosity depending on the depth was formed along the impurity region 23 (FIG. 2G).

  Next, the mask 22 was peeled off, and the substrate was immersed in a hydrofluoric acid: hydrogen peroxide: water = 2: 8: 90 solution for 30 minutes to remove the porous region 25 by etching. A three-dimensional hollow structure Si substrate in which the hollow regions 26 were partially arranged in a multilayer was formed (FIG. 2 (h)).

  When the substrate was immersed in the solution for 15 minutes, only the porous region on the surface was left, and the porous region 25 was removed by etching. A three-dimensional hollow structure Si substrate in which the porous region 25 and the hollow region 26 are partially arranged in layers was formed (FIGS. 3G and 4G described later).

  The first embodiment and the second embodiment have been described above. Next, examples of various forms of the hollow region will be described.

  3 and 4 are a cross-sectional view and a top view showing examples of various forms of the hollow region in the three-dimensional hollow structure. (A) to (g) in FIG. 3 correspond to (a) to (g) in FIG. 4, respectively. A hollow region in which each part is arranged in multiple layers is shown.

  One or more hollow regions exist in the same structure. When there are a plurality of them, their three-dimensional shapes may be the same or different.

  (A) has shown that the three-dimensional shape of a hollow area | region is arbitrary. That is, the vertical cross-sectional shape (lateral width) changes with respect to the depth direction. In the hollow region corresponding to the porous region of one layer, the vertical cross-sectional shape is the same, but may be monotonously changed as shown in FIG. 13 of the third embodiment described later. If the thickness of each porous region and the vertical cross-sectional shape are freely selected, the three-dimensional shape of the hollow region can be arbitrarily designed.

  (B) is an example having two or more hollow regions in the same structure.

  (C) to (e) are examples in which two or more separated hollow regions are joined at a certain depth.

  (F) is an example in which the hollow region communicates with the external space on both end faces of the structure.

  (G) is an example in which porous regions are mixed.

[Third embodiment]
Hereinafter, the third embodiment will be described exclusively as an example in which the first embodiment in which the porous region in the non-porous Si is removed to form the hollow region in the method of manufacturing the ejection head of the ink jet recording apparatus is applied. However, the second embodiment in which the impurity region in the non-porous Si is removed to form the hollow region can also be applied. The “hollow region” and the “porous region” in the first and second embodiments correspond to the “space portion” and the “porous portion”, respectively, in the third embodiment.

In the ejection head of the ink jet recording apparatus manufactured according to the present embodiment, first, the ejection head using the d ₃₁ mode bending displacement using the vibration plate will be described.

FIG. 5 is a schematic view of the ejection head in the d ₃₁ flexure mode, FIG. 6 is a sectional view of the individual liquid chamber of the ejection head viewed from the short side direction, and FIG. 7 is the longitudinal direction of the individual liquid chamber of the ejection head. It is sectional drawing seen from.

  In the figure, 31 is a piezoelectric film, 32 is a lower electrode, 33 is a diaphragm, 34 is an upper electrode, 35 is an individual liquid chamber, 36 is a discharge port, 37 is a communication hole connecting the individual liquid chamber and the discharge port, 38 is Si substrate. By applying a voltage between the upper and lower electrodes sandwiching the piezoelectric film, the diaphragm suppresses the piezoelectric film from expanding and contracting, so that the vibrating plate is displaced in the vertical direction on the individual liquid chamber side to fill the liquid chamber. Pressure is applied to the liquid and droplets are discharged from the discharge port. In FIG. 7, 51 is a liquid supply path, 52 is a common liquid chamber.

  The ejection head manufactured according to the present embodiment has, for example, the above-described configuration, but is an ejection head that does not have any one of the junctions 41, 42, and 43 illustrated in FIG. The ejection head does not have a portion. “Discharge head that does not have any of the joints” means, for example, a three-dimensional structure that is formed of the same material in a region having different shapes and cross-sectional areas of the individual liquid chambers or liquid flow paths and does not have a joint. Means a hollow structure. In particular, the discharge head has a small etching removal portion, which is impossible with normal etching, and has a portion with a large area in the direction in which etching stops, and does not have a bonding portion or an adhesion portion in that region.

  FIG. 8 is a diagram illustrating an example of a three-dimensional hollow structure that does not have a joint in the etched space. (A), (b) is sectional drawing of each of a transversal direction and a longitudinal direction.

In the figure, the area of the space 62 is small in the spaces 62 and 63 in which the vibration plate 61 is etched away in the direction of functioning as an etch stop layer, and the space 63 has a large area through the space 62 and 63. The hollow structure does not have a joint portion or an adhesive portion. Further, the present embodiment is characterized in that there is no portion of a different material between the thin film of the vibration plate 61 and the housing portion 64. Although it is within the scope of the present invention, a substrate having a discharge port is joined to the structure having the liquid supply path and the individual liquid chamber in FIG. 8 to form a liquid discharge head, the portion having the discharge port is also integrally formed. More preferably. Although the above embodiment has been described with an example of a d ₃₁ mode flexural mode piezoelectric head having a diaphragm, the present invention having no joint is characterized by a d ₃₃ mode / d ₃₁ mode piston mode, d It is implemented in all of ₁₅ modes, electrostatic heads, thermal heads using heat, and the like.

FIG. 9 shows a schematic diagram of a discharge head of the d ₃₃ mode called piston mode.

  In the figure, reference numerals 71 and 71 ′ denote laminated piezoelectric films, reference numeral 33 denotes a diaphragm, and reference numeral 36 denotes a discharge port. In the laminated piezoelectric films 61 and 61 ′, a plurality of electrode layers are laminated so that the electric field strength applied to one piezoelectric film is increased. The number of layers of the laminated piezoelectric film is designed from 2 layers to 100 layers depending on the ejection amount and ejection force from the ejection head.

FIG. 10 shows a schematic diagram of a discharge head of the d ₁₅ mode called shear mode.

  In the figure, reference numeral 81 denotes a piezoelectric film, on which a comb electrode (not shown) is provided, an electric field is applied obliquely in the piezoelectric film, and liquid is discharged by displacement of the piezoelectric film.

  FIG. 11 shows a schematic cross-sectional view of an ejection head having a heating element.

  In the figure, 36 and 36 'are discharge ports, 35 is an individual liquid chamber, and the discharge ports 36 and 36' are arranged in a staggered arrangement. Reference numeral 92 denotes a liquid supply path, and 91 denotes a heating element. Reference numerals 93, 94, and 95 are Si material portions, and as described above, no bonding layer or adhesive layer is interposed therebetween. The heating element is formed by a thin film forming method, but may have a structure at 93 or 94.

  FIG. 12 is a schematic cross-sectional view in the longitudinal direction of the electrostatic liquid discharge head.

  In the figure, 101 is a diaphragm, 102 is a discharge port, 103 is an individual liquid chamber, and 105 is a common liquid chamber. The material constituting at least the above part is made of Si material, and there is no bonding layer or adhesive layer between these layers. Reference numeral 104 denotes a gap portion, 106 denotes an insulating layer, and 107 denotes an electrode. The interface between the insulating layer 106 and the electrode 107 may be bonded, or an electrode may be formed on the insulating layer. In the conventional electrostatic discharge head, the substrate having the discharge port and the substrate having the vibration plate are formed by bonding and bonding even if they are made of the same material. The present invention provides a discharge head having a long life and good environmental resistance since there is no such different layer.

  Applying water repellent treatment to the surface on the discharge port side of each discharge head is a preferable aspect in terms of aligning the droplet discharge direction.

  Next, the manufacturing method of the ejection head of the present invention will be described.

  The method for producing a discharge head according to the present invention includes a step of forming a porous portion in a Si substrate, a Si layer is formed on the substrate on which the porous portion is formed, and a porous portion is formed in the Si layer. Forming a mass part, forming a liquid discharge source, and removing the porous part to form at least an individual liquid chamber and a liquid supply path communicating with the individual liquid chamber. The porous part is a part where the density is low and the etching rate is one digit or more faster than that of the non-porous part. Therefore, when an etching process is performed, the porous portion is selectively removed, and the target three-dimensional hollow structure is obtained.

  Further, the discharge port can be formed together with the individual liquid chamber and the liquid supply path communicating with the individual liquid chamber.

  In the manufacturing method of the discharge head of the present invention, after forming the individual liquid chamber having one side opened, the discharge port, and the communication hole connecting the discharge port and the individual liquid chamber by this method, the upper and lower electrodes on another substrate, It is possible to produce a discharge head by joining a piezoelectric film and a diaphragm, but preferably after forming the diaphragm, an electrode and a piezoelectric film are formed, and then a porous film is formed. The step of removing the part is preferable.

  Next, main techniques constituting the method of manufacturing the ejection head according to the present invention will be described.

  In the present invention, the step of partially forming a porous portion on a Si substrate, the step of forming a Si epitaxial layer thereon, and the step of partially forming a porous portion in the Si layer are performed at least once. The method of manufacturing a device by removing a porous portion in an etching process is applied to a method of manufacturing a discharge head. In a discharge head having a three-dimensional structure, for example, a device is manufactured by forming an individual liquid chamber, a flow path portion, and the like with a porous portion and finally removing the portion. For this reason, there are essentially no joints and adhesions in the three-dimensional hollow structure, and the device is free from problems such that the film is peeled off due to warping due to stress or thermal effects. As a method for forming the porous portion, anodizing treatment is performed, but other methods may be used.

  In order to selectively perform the porous portion, a mask layer is formed on the Si surface, and the portion without the mask is subjected to chemical conversion treatment to become a porous portion. The mask material may be any material that is not easily damaged by chemical conversion treatment such as SiC, SiN, amorphous Si, polymer, and wax. After the chemical conversion treatment, the mask is removed, a single crystal Si film is formed on the porous portion, and a mask is formed and chemical conversion treatment is performed so as to further create a porous portion as necessary. Finally, a functional layer (for example, a piezoelectric element or a heating element) is formed on the Si substrate having the porous part created in this way as needed, and the porous part is removed by etching to form a space part as an ejection head. Can be formed. The functional layer may be formed after the porous portion is removed by etching. As described above, the material that holds the functional layer serving as the discharge source forms a three-dimensional space portion together with the housing, and the discharge head can be formed of substantially the same material as the constituent material of the discharge head.

  Since the porous part is a layer whose density is reduced to less than half, the chemical etching rate is significantly increased compared to the etching rate of a normal single crystal layer, only the porous part is removed, and the porous part is porous. It is possible to provide a three-dimensional hollow structure having no joint in the structure from which the portion has been removed.

  The porous part may have a structure with different densities in the layer, or the density of different porous parts in the substrate may be different. It is preferable because the dimensions are as designed by making the etching rate different because the volume of the porous portion is different. This is achieved by changing the current density during the anodization process.

  The discharge head manufactured in this way has a structure without a bonding layer and an adhesive layer in a three-dimensional hollow structure made of Si material in which individual liquid chambers, liquid flow paths, and / or discharge ports are included.

  FIGS. 13A to 13J are diagrams showing a process of forming a three-dimensional hollow structure of Si material without a bonding layer and an adhesive layer.

FIG. 13 shows an example of a process of manufacturing a discharge head in the d ₃₁ flexure mode, and only one portion serving as an individual liquid chamber is shown for the sake of simplicity. Created in the form. (A) is a state in which a mask 112 is formed on the front and back surfaces of the Si substrate 111. The state in which this is anodized and the mask is removed is (b). Reference numeral 113 denotes an anodizing treatment section. A single crystal Si layer 114 is formed by epitaxially growing Si on the anodized porous portion including the porous portion ((c)). Further, a mask 112 is formed as shown in (d), and the porous portion 115 is formed by anodizing treatment ((e)). Further, an Si layer 116 is formed thereon ((f)) as in the step (c). The substrate thus prepared is a substrate made of the same material that encloses the porous portion. In order to form a d ₃₁ mode piezoelectric element using the flexure mode thereon, a lower electrode 117, a piezoelectric film 118, and an upper electrode 119 are provided on the Si layer 116 corresponding to the diaphragm as shown in (g). . In (g), the upper electrode and the piezoelectric film are illustrated in a state of being patterned on the porous portion serving as the individual liquid chamber, but usually the piezoelectric film and the upper electrode are formed on the entire lower electrode. Thereafter, patterning is performed by an etching process or the like. Alternatively, when the piezoelectric film is formed by a method such as the aerosol deposition method, the film can be formed through a mask, so that the patterned piezoelectric film is formed without the etching process.

  Subsequently, 120 in (h) means that the porous portion has been removed by etching to become a space portion.

  The discharge head thus formed may be used as it is, or may be formed by bonding a substrate 121 having a discharge port portion 122 at the tip as shown in (i). A method in which an anodizing process is performed on the Si substrate and the individual liquid chamber part 123 is prepared by the above method is also within the scope of the present invention, and the latter is a more preferable embodiment. In this case, as shown in (j), an integrated discharge head which is entirely made of Si and does not have 124 junctions can be obtained. Further, the part to be etched away may be a part other than the porous part by other processes such as a dry process to complete the three-dimensional shape. That is, the present invention is a method of manufacturing a discharge head device having no joint or adhesive inside the three-dimensional hollow structure. As one of the means for realizing the method, the porous portion and the Si layer are formed once. The manufacturing method in which at least a part of the porous portion is removed as described above is exemplified.

  In a discharge head having an individual liquid chamber, a discharge port, a liquid discharge source, and a communication hole connecting the individual liquid chamber and the discharge port, the communication hole and the discharge port can be easily obtained by using the dry process and the removal means of the porous portion in combination. The discharge head is characterized in that the shape includes a portion having a tapered shape from the individual liquid chamber and a portion having a constant diameter in the vicinity of the discharge port. For example, an ejection head having a portion 120 having a tapered shape as shown in FIG. 13 and a portion 122 having a constant diameter up to the ejection port can be obtained, and this shape improves droplet ejection characteristics. With an ejection head using a piezoelectric film, having the above structure makes it possible to obtain an ejection head with good characteristics. That is, by having a tapered portion, the decrease in pressure waves is reduced, and by performing meniscus control at a portion having a constant aperture, constant and stable meniscus control can be performed according to the displacement amount of the diaphragm. A certain amount of droplets can be discharged stably and at high speed.

  When the angle of the tapered portion is θ, the difference between the large diameter and the small diameter is 2a, and the film thickness having the taper is b, θ is preferably 50 ° or more and 86 ° or less when defined as tan θ = b / a. The diameter of the fixed portion is preferably 10 to 40 μm.

  The anodizing treatment is desirably performed in an HF solution. An ethanol solution of HF is preferred. In order to create a porous Si layer by anodizing treatment, holes are required in the single crystal Si layer, and P-type Si is easier to be transformed into porous Si than N-type Si. Si can also be dealt with by injecting holes.

  The structure of porous Si can be controlled by the solution concentration, current density, and Si resistivity. Further, the thickness of the porous portion is controlled by the time of anodizing treatment. During the production process, it is a preferred embodiment that dry oxidation is performed in the range of 200 ° C. to 500 ° C. to oxidize the inner walls of the pores of the porous portion. A preferred temperature range is 300 ° C to 450 ° C. Through this process, even if there is a process of 700 ° C. or higher in the process of forming and forming a functional film (for example, a piezoelectric film or a resistance film for a heating element) in a later process, the aggregation of holes occurs. In addition, the etching characteristics are not deteriorated.

An Si layer is epitaxially formed on the substrate on which the porous portion is partially formed (for example, step (c) in FIG. 13). This epitaxial film formation can be performed by a normal method, for example, it can be formed by a low pressure CVD method using a source gas of SiH ₄ .

  In the present invention, the porous part forming step and the Si layer forming step can be repeated a plurality of times. By repeating a plurality of times, porous portions having different dimensions are three-dimensionally arranged in the substrate. After creating these, the functional layer may be formed, or the functional layer may be formed during the formation of the porous portion and the Si layer.

Next, the d ₃₁ piezoelectric film for flexure mode of the present embodiment will be described.

  The piezoelectric film is formed on the epitaxially formed Si layer via a lower electrode. As the forming method, as a thin film forming method, a sputtering method, a CVD method, a sol-gel method, an MBE method, a PLD method, a hydrothermal synthesis, a gas deposition method, or the like is used. A ceramic or single crystal produced by a sintering method or a melting method may be formed by cutting a thin film and then joining, but it is preferably formed by a thin film forming method.

The piezoelectric film of this embodiment means a piezoelectric film and / or an electrostrictive film. Examples of the material used for the piezoelectric film include perovskite compounds. For example, an electrostrictive material of the piezoelectric material and a relaxor material such as lead zirconate titanate PZT _{(TM) [Pb (Zr X Ti 1} -X) O 3] or barium titanate BaTiO _3. MP of lead zirconate titanate (PZT) preferably has a morphotoropic phase boundary (MPB) composition of 0.45 to 0.65, but other composition ratios may be used.

  The following materials can be selected as the electrostrictive material used in the present embodiment.

For _{example, PMN [Pb (Mg X Nb} 1-X) O 3], PNN [Pb (Nb X Ni 1-X) O 3], PSN [Pb (Sc X Nb 1-X) O 3], PZN [Pb _{(Zn X Nb 1-X)} O 3], PMN-PT {(1-y) [Pb (Mg X Nb 1-X) O 3] -y [PbTiO 3]},
_{PSN-PT {(1-y} ) [Pb (Sc X Nb 1-X) O 3] -y [PbTiO 3]}, PZN-PT {(1-y) [Pb (Zn X Nb 1-X) O ₃ ] -y [PbTiO ₃ ]}, LN [LiNbO ₃ ], KN [KNbO ₃ ].

  Here, x and y are numbers of 1 or less and 0 or more. For example, in the case of PMN, x is 0.2 to 0.5, and in PSN, x is preferably 0.4 to 0.7, PMN-PT y is 0.1 to 0.4, and PSN-PT y is 0.3 to 0.5 and y of PZN-PT is preferably 0.03 to 0.35. Further, PMN-PZT, PZN-PZT, PNN-PZT, and PSN-PZT compounds in which Zr is substituted for Ti in PMN-PT, PZN-PT, PNN-PT, and PSN-PT may be used.

The piezoelectric layer is preferably an ABO ₃ type perovskite oxide.

  The piezoelectric film may have a single composition or a combination of two or more. Moreover, the composition which doped the trace amount element to the said main component may be sufficient. The piezoelectric / electrostrictive film of this embodiment is preferably crystal-controlled in order to exhibit excellent piezoelectricity. Preferably, it is a pseudo-cubic crystal or a mixed phase system in which at least two of pseudo-cubic, rhombohedral and tetragonal crystals exist.

  As described above, sputtering method, MO-CVD method, laser ablation method, sol-gel method, MBE method, etc., preferably sputtering method, MO-CVD method, sol-gel method. More preferably, the MO-CVD method and the sputtering method are used.

  As a condition other than the substrate temperature according to the MO-CVD method, it is preferable to adopt a pulse MO-CVD method in which the source gas is supplied continuously rather than continuously on the substrate.

When the crystal of the piezoelectric film is controlled, it is preferable to form a buffer layer on the Si substrate in order to obtain lattice matching. The buffer layer is preferably a fluorite-type oxide and has a thickness of 10 nm to 5 μm. The fluorite type oxide, for _{example, AmO 2, CeO 2, CmO} 2, K 2 O, Li 2 O, Na 2 O, NpO 2, PaO 2, PuO 2, RbO 2, TbO 2, ThO 2, UO ₂ , ZrO ₂ , preferably CeO ₂ , ZrO ₂ , and a crystal structure in which the (100) plane of the buffer layer is parallel to the diaphragm surface is preferable. ZrO ₂ preferably contains a rare earth element as a dopant.

As a piezoelectric film of the bending mode d ₃₁ or piston mode d ₃₃ mode, a plurality of layers of the above materials are sandwiched between electrodes. The film thickness per layer is 0.5 μm to 20 μm, and the number of layers is 2 or more and 100 or less, but preferably 5 or more and 50 or less. For the electrodes between the layers, metal materials such as Pt, Ni, Cu, Cr, Au, Ir, and Ru are preferably used, and in order to prevent leakage, alternate electrode layers are not exposed to the end faces as shown in FIG. Stopped on the way. These laminated piezoelectric layers may be made of a polycrystalline material and may be made of a BaTiO ₃ based material.

  In the piston mode discharge head, the diaphragm does not need to be made of Si material, and may be formed by forming the individual liquid chambers with Si material and bonding and bonding a thin film diaphragm thereon. As a diaphragm made of a material other than Si, a polymer material such as polyimide or a metal material such as Ti foil may be used. In order to align the diaphragm and the laminated piezoelectric film, a metal material, a polymer material, or a glass material that serves as a protrusion may be provided on the diaphragm. These protrusions and the laminate are joined using an adhesive.

The piezoelectric film of the discharge head of the d ₁₅ mode of the present embodiment may not be patterned as illustrated in 81 in FIG. 10, one piezoelectric-electrostrictive film of the individual liquid chamber having a constant thickness Bonded and bonded in a closed form. The piezoelectric-electrostrictive film, the electric field is arranged comb-shaped electrodes are subjected to an oblique direction with respect to the film thickness of the piezoelectric film 81, d ₁₅ mode becomes available.

  The following materials are used as the heating elements of the ejection head using thermal displacement as the ejection source of the present embodiment.

  A thin film heating element of TaN or TaNSiN is used. Other than that, a general thin film heating element may be used, and examples thereof include a cermet material, poly-Si, an alloy, and a metal compound.

  Examples of these film forming methods include sputtering, vacuum deposition, CVD, and coating.

  Further, a protective film for protecting from ink is formed as necessary.

  FIG. 14 is a schematic diagram of an ink jet recording apparatus using the ink jet head manufactured according to the present embodiment. The configuration is the same as that disclosed in Patent Document 4 above. Thus, the present invention can achieve an ink jet recording apparatus with stable ejection characteristics, a long-life ink jet head, and good performance.

  In the apparatus main body 131 of FIG. 14, a lower case 132, an upper case 133, and an access cover 134 are exteriors, 135 is a paper discharge tray, and 136 is an automatic feeding unit.

  FIG. 15 shows the operating mechanism part with the exterior of FIG. 14 removed. An automatic feeding unit 137 for automatically feeding a recording sheet as a recording medium into the apparatus main body, and a recording sheet sent from the automatic feeding unit 136 are guided to a predetermined recording position, and from the recording position to the discharge port 141. And a transport unit 142 that guides the recording paper, a recording unit 143 that performs recording on the recording paper transported to the recording position, and a recovery unit 144 that performs recovery processing on the recording unit 143. The ink jet head of this embodiment is disposed on the carriage 145 and used. Although FIG. 14 shows an example of a printer, the discharge head according to the present embodiment may be used for a fax, a multifunction peripheral, a copying machine, or an industrial discharge apparatus.

Next, the present embodiment will be described with respect to each of the ejection heads in the d ₃₁ bending mode and the d ₃₃ piston mode.

[Example 3-1]
FIG. 16 is a cross-sectional view of the ejection head in the d ₃₁ flexure mode viewed from the longitudinal direction.

In FIG. 13, a SiN mask 112 is formed so that the porous portion forms tapered portions 113 as shown in the figure on both surfaces of a 100 μm thick Si substrate as the substrate 111. The opening on the upper surface was designed to be 45 μmφ, and the opening on the lower surface was designed to be 25 μmφ. Anodization treatment was performed in a solution having a current density of 30 mA / cm ² and HF: H ₂ O: ethanol = 1: 1: 1, and the porous portion was penetrated from the upper surface to the lower surface. After removing and cleaning the mask using hot phosphoric acid, a single-crystal Si layer is formed with a thickness of 40 μm by low-pressure CVD on the upper surface side. As shown in the longitudinal sectional view of FIG. A porous part was created. Further, a 40 μm Si layer was formed, and the portion corresponding to 153 was similarly processed to be a porous portion. Further, a Si layer having a thickness of 20 μm was formed thereon, and the portions 155 and 156 were similarly made porous portions. On top of this, Si157 was further epitaxially formed with a thickness of 4 μm to prepare a diaphragm. The vibration plate 157 has the same (100) crystal structure as the Si crystal structure of the substrate 111. Further, the portion 158 was made porous. The porous portion 151 side is a portion that becomes an individual liquid chamber, and the porous portion 152 side is a portion that becomes a common liquid chamber. A central portion 154 of the porous portion 153 is a portion serving as a liquid supply path for the common liquid chamber and the individual liquid chamber. Reference numeral 158 denotes a portion serving as a liquid supply port.

  Thereafter, a Si layer was formed on the lower surface side of the substrate for forming the discharge port, and the discharge port 161 was drilled in the layer by a dry process (diameter 25 μm). Thereafter, a lower electrode 162, a piezoelectric film 163, and an upper electrode 164 are formed. Before forming these, heat treatment is performed at 200 to 450 ° C. as described above. In addition, a buffer layer is preferably provided between the lower electrode 162 and the diaphragm 157. In this way, a device having no bonding layer, adhesive layer or the like in the three-dimensional hollow structure can be obtained. In addition, there was a communication hole connecting the individual liquid chamber and the discharge port, and the shape from the individual liquid chamber to the discharge port was initially tapered, and a constant diameter was obtained on the discharge port side.

  Thus, the ejection head of the present invention can be obtained by patterning the upper electrode and the piezoelectric film and removing the porous portion by wet etching. During the above-described treatment, it is preferable to protect the polymer with a polymer material or the like so as not to cause etchant contamination in unnecessary portions as necessary. In particular, it is preferable to use a protective material resistant to a hydrofluoric acid-based solution which is an etchant.

A voltage of 25 V was applied to the discharge head to discharge a liquid having a viscosity of 3.8 cps, and the characteristics were evaluated. The droplet amount and the discharge speed were converted from the droplet size and moving distance by a high-speed camera, and values of 2.5 pL and 7.8 m / second were obtained. Moreover, the discharge head is durable, that no initial major characteristics decrease was confirmed in the discharge of more than 10 ⁹ times.

[Example 3-2]
Figure 17 is a sectional view seen from the longitudinal direction of the ejection head of d ₃₃ piston mode.

  As shown in the cross-sectional view in the longitudinal direction of FIG. 17, a porous portion 174 serving as a discharge port was formed in the substrate. Further, in the same manner as in the above method, a multi-layer porous portion 175 serving as an individual liquid chamber and a multi-layer porous portion 176 serving as a common liquid chamber were formed by repeating a plurality of steps. These porous parts are removed by wet etching to form cavities, and have liquid supply ports, common liquid chambers, individual liquid chambers, flow paths between liquid chambers, and discharge ports, and tertiary layers without bonding layers and adhesive layers in them. An original hollow structure was obtained. As in Example 3-1, 154 is a portion that serves as a liquid supply path for the common liquid chamber and the individual liquid chambers, and 158 is a portion that serves as a liquid supply port. A diaphragm having a thickness of 100 μm was adhered so as to block the porous portion 177, and a dicer-cut laminated piezoelectric material was placed thereon, thereby obtaining an ejection head shown in the schematic diagram of FIG. Although the laminated piezoelectric bodies 71, 71 'and the like are not shown, a common substrate for holding them is disposed.

  When a voltage of 15 V was applied between the piezoelectric layers and ejection of a liquid of 3.8 cps was attempted, it was possible to eject accurately with a droplet volume of 5 pl and a droplet ejection speed of 6 m / sec.

[Example 3-3]
A diaphragm was formed by epitaxially forming a Si layer with a thickness of 3.5 μm on the porous portion 177 of the substrate shown in FIG. This was heated at 400 ° C. for 30 minutes, and then the diaphragm was cleaned, and the SiO ₂ layer was removed. Then, a Y-containing stabilized zirconia layer having a thickness of 20 nm was formed by sputtering under heating at 800 ° C. (100). did. On this, a perovskite type metal oxide electrode 150 nm is epitaxially formed with a (001) / (100) orientation, and a piezoelectric film having a Pb _1.05 (Zr _0.55 Ti _0.45 ) O ₃ composition is formed thereon. (100) epitaxial formation was performed with a thickness of 3 μm. The piezoelectric film is a pseudo cubic system or a crystal system in which at least two of a pseudo cubic system, a rhombohedral system, or a tetragonal system are mixed, so that the characteristics of the piezoelectric film can be improved. I was able to improve. A perovskite-type metal oxide electrode was placed as the upper electrode, and the upper electrode and the piezoelectric film were patterned to correspond to the individual liquid chambers by etching. Thereafter, the piezoelectric element side was protected with a polymer, and then the porous portion was removed with a hydrofluoric acid / acetic acid-based aqueous solution to obtain an ejection head according to the present invention.

  With the above-described configuration, the discharge head can discharge droplets with good characteristics even when the density is increased to 480 dpi per line, and it is possible to discharge 6 cps with high viscosity.

Sectional drawing which shows typically the preparation methods of the three-dimensional hollow structure which concerns on the 1st Embodiment of this invention Sectional drawing which shows typically the preparation methods of the three-dimensional hollow structure which concerns on the 2nd Embodiment of this invention. Sectional view schematically showing an example of a three-dimensional hollow structure Top view schematically showing an example of a three-dimensional hollow structure d ₃₁ Schematic diagram of ejection head in flexure mode Similarly, a cross-sectional view of the individual liquid chamber of the discharge head as seen from the short side Similarly, a sectional view of the individual liquid chambers of the discharge head as seen from the longitudinal direction The figure which shows the example of the three-dimensional hollow structure which does not have a junction part in the space part removed by etching d Schematic of _33- piston mode discharge head d Schematic of the discharge head in ₁₅ share mode Schematic cross-section of a discharge head using a heating element Longitudinal cross-sectional schematic view of an electrostatic liquid discharge head Diagram showing the process of forming a three-dimensional hollow structure of Si material without a bonding layer or adhesive layer Schematic diagram of inkjet recording device Schematic diagram of the operation mechanism of the ink jet recording apparatus d _{31 is} a sectional view of the ejection head in the flexure mode as seen from the longitudinal direction d Cross section viewed from longitudinal direction of _33- piston mode discharge head The figure which shows Si substrate of the prior art, and its processing method

Explanation of symbols

11, 21 ... non-porous Si
12, 22 ... Mask 13, 25 ... Porous region 14, 24 ... Non-porous Si layer (epitaxial layer)
DESCRIPTION OF SYMBOLS 15,26 ... Hollow area | region 23 ... Impurity area | region 31 ... Piezoelectric film 32 ... Lower electrode 33 ... Diaphragm 34 ... Upper electrode 35 ... Individual liquid chamber 36 ... Discharge port 37 ... Communication hole 38 ... Si substrate 51 ... Liquid supply path 52 ... Common liquid chamber 61 ... Diaphragm 71, 71 '... Multilayer piezoelectric film 81 ... Piezoelectric film 91 ... Heating element 120 ... Space (hollow region)

Claims (9)

  Forming a porous region partially in the silicon substrate, forming a silicon layer on the substrate on which the porous region has been formed, and forming a porous region partially in the silicon layer; A method for producing a three-dimensional hollow structure comprising at least a step of forming a hollow region by etching away a porous region.   The manufacturing method according to claim 1, wherein a step of further forming a silicon layer on the silicon layer in which the porous region is formed and partially forming the porous region in the silicon layer is repeated.   A step of partially forming a high-concentration impurity region in a silicon substrate, a step of forming a silicon layer on the substrate on which the high-concentration impurity region has been formed, and a step of partially forming a high-concentration impurity region in the silicon layer; A method for producing a three-dimensional hollow structure comprising at least a step of forming a porous region in the high-concentration impurity region and a step of forming a hollow region by etching away the porous region.   4. The manufacturing method according to claim 3, wherein a step of further forming a silicon layer on the silicon layer in which the high concentration impurity region is formed and partially forming the high concentration impurity region in the silicon layer is repeated. Method.   5. The method according to claim 3, wherein the step of forming the high concentration impurity region includes at least two types of ion implantation steps and a diffusion step.   The method according to claim 1 or 3, wherein the porous region is a region having two or more layers having different porosities.   The method according to claim 1 or 3, wherein the step of forming the porous region includes at least an anodizing step or a stain etching step.   The manufacturing method according to claim 1 or 3, wherein a part of the porous region is removed in the step of forming the hollow region by removing the porous region by etching.   A step of partially forming a porous portion in a silicon substrate, a step of forming a silicon layer on the substrate on which the porous portion is formed, and a portion of forming a porous portion in the silicon layer, a liquid discharge source And a step of forming at least the individual liquid chamber and a liquid supply path communicating with the individual liquid chamber by removing the porous portion.

Images