JPWO2011099316A1 - Inkjet head manufacturing method - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing an inkjet head capable of producing a highly reliable inkjet head without adversely affecting the ejection characteristics and without having to peel off the support substrate. A method of manufacturing an ink jet head in which a pressure chamber is formed on the other surface of a diaphragm patterned on the surface, the first step of forming pressure generating means on a substrate 1, and a wiring layer 2 A second step of producing the upper layer 3 having the base material 1 and the wiring layer 2 by forming the pressure generating means on the surface of the material 1 and the base material 1 in the upper layer 3 are pressure-generated. A third step of forming a diaphragm by processing the diaphragm from a surface opposite to the surface where the means is formed into a thin film, and a surface for forming the pressure generating means in the diaphragm processed into a thin film; Has a pressure chamber on the opposite side And having a fourth step of forming a lower layer.

Description

  The present invention relates to a method of manufacturing an ink jet head, and more specifically, a pressure chamber is formed by a diaphragm and a concave portion by bonding a layer having a concave portion to the other surface of the diaphragm in which pressure generating means is patterned on one surface. The present invention relates to a method for manufacturing an ink jet head that constitutes the above.

  The inkjet head uses a piezoelectric element such as PZT that converts electrical signals into mechanical energy as pressure generating means for ejecting ink from the nozzles, and a diaphragm formed on one surface of the pressure chamber is vibrated by the piezoelectric element. Thus, there is a type that gives a pressure change for ejecting ink in a pressure chamber from a nozzle. Among them, there is known an inkjet head formed by using a thin film PZT as a piezoelectric element and growing it on the outer surface of a diaphragm by sputtering (Patent Documents 1 and 2).

  The diaphragm needs to be thinned to an order of about 1 to 10 μm in order to exhibit its performance. However, if the diaphragm is made thin, there is a problem that handling during the manufacturing process is impossible. In general, a plate-like body having a thickness of 100 μm or less needs to be supported by some kind of base material.

In Patent Document 1, a substrate in which a recess is filled is prepared by filling a glass paste in the recess of a Si substrate in which a recess serving as a pressure chamber is formed and heat-curing, and a diaphragm is formed on the substrate. to form a film a thin film made of SiO _x to be, and to be stacked by sputtering the lower electrode, PZT film and an upper electrode on the thin film. That is, the Si substrate in which the recess for the pressure chamber is filled is used as a base material when the diaphragm is handled. After the PZT film is formed, the glass filled in the recesses is removed by melting with HF, and a thin film made of SiO _x is used as a diaphragm, and a pressure chamber is formed by the diaphragm and the recesses. Yes.

  Further, in Patent Document 2, a resin adhesive is applied to a support substrate, and a diaphragm is bonded to the upper surface of the support board to temporarily fix it, and a lower electrode, a PZT film, and an upper electrode are laminated on the diaphragm by sputtering. ing. That is, the support substrate is used as a base material for handling the diaphragm. After the PZT film is formed, an upper substrate having wiring for applying a voltage to the PZT is laminated on the PZT, and then the resin adhesive is dissolved using an adhesive stripping solution to vibrate the support substrate. The pressure chamber is formed by the vibration plate and the concave portion by peeling the plate from the plate and laminating the flow path substrate on which the concave portion serving as the pressure chamber is formed on the lower surface of the vibration plate.

JP 2007-190856 A JP 2006-281777 A

  In the method of Patent Document 1, there is a problem that a residue remains in the recess when the glass filling the recess serving as the pressure chamber is melted, thereby adversely affecting the ejection characteristics of the manufactured inkjet head.

  In addition, in the method of Patent Document 2, since the support substrate once bonded must be peeled later, not only the manufacturing process becomes complicated, but also when the support substrate is peeled by dissolving the resin adhesive, There was a problem that the diaphragm could not be peeled off.

  For this reason, any of the above methods has a poor yield, and it has not been possible to produce a highly reliable ink jet head that does not adversely affect the ejection characteristics.

  In view of this, the present invention provides an injection when a pressure chamber is formed by a diaphragm and a recess by forming a layer having a recess on the other surface of the diaphragm on which pressure generating means is patterned on one surface. It is an object of the present invention to provide a method for manufacturing an ink jet head that can produce a highly reliable ink jet head without adversely affecting the characteristics and without having to peel off the supporting substrate.

  The above problems are solved by the following inventions.

The invention according to claim 1 is a method for manufacturing an ink jet head, wherein the pressure generating means forms a pressure chamber on the other surface of the vibration plate patterned on one surface,
A first step of forming the pressure generating means on a base material that includes the diaphragm and is thicker than the thickness of the diaphragm;
An upper layer having the substrate and the wiring layer is formed by forming a wiring layer having a wiring for supplying power to the pressure generating unit on a formation surface of the pressure generating unit in the substrate. A second step to produce;
A third step of forming the diaphragm by processing the base material in the upper layer into a thin film shape, leaving a thickness of the diaphragm from a surface opposite to a surface on which the pressure generating unit is formed;
A method of manufacturing an ink jet head, comprising: a fourth step of forming a lower layer having the pressure chamber on a surface opposite to a surface on which the pressure generating unit is formed in the diaphragm processed into a thin film. It is.

In the invention according to claim 2, the base material has a thin film made of SiO ₂ having a thickness to be the diaphragm formed on one surface of the Si substrate,
The first step forms the pressure generating means on the thin film of the base material,
2. The method of manufacturing an ink jet head according to claim 1, wherein the third step processes the thin film by removing the Si substrate while leaving the thin film of the base material.

As for invention of Claim 3, the said base material is comprised only by Si substrate,
2. The method of manufacturing an ink jet head according to claim 1, wherein the third step is to process the Si substrate into a thin film by removing the Si substrate while leaving a thickness to be the vibration plate. 3.

  According to a fourth aspect of the present invention, in the fourth step, the lower layer is formed of a glass substrate having a through hole serving as the pressure chamber and a nozzle plate made of a Si substrate, and is processed into the thin film shape. 4. The method of manufacturing an ink jet head according to claim 3, wherein the bonding is integrally performed to the Si substrate without using an adhesive.

  A fifth aspect of the present invention is the method of manufacturing an ink jet head according to any one of the second to fourth aspects, wherein the removal of the Si substrate is an etching process.

  A sixth aspect of the present invention is the method of manufacturing an ink jet head according to any one of the second to fourth aspects, wherein the removal of the Si substrate is a polishing process.

  According to the present invention, when the pressure chamber is formed by the diaphragm and the recess by forming the layer having the recess on the other surface of the diaphragm having the pressure generating means patterned on one surface, the injection is performed. It is possible to provide a method for manufacturing an ink jet head that can produce a highly reliable ink jet head without adversely affecting the characteristics and without having to peel off the supporting substrate.

Process drawing explaining the 1st process in 1st Embodiment Process drawing explaining the 2nd process (manufacture of a wiring layer) in 1st Embodiment Process drawing explaining the 2nd process (manufacture of a wiring layer) in 1st Embodiment Process drawing explaining the 2nd process (production of an upper layer) in a 1st embodiment Process drawing explaining the 3rd process in a 1st embodiment Process drawing explaining the 4th process in a 1st embodiment Process drawing explaining the 3rd process in 2nd Embodiment Process drawing explaining the 4th process in 2nd Embodiment Process drawing explaining the 4th process in 3rd Embodiment Process drawing explaining the manufacturing method of the lower layer in 3rd Embodiment

  The present invention relates to a method of manufacturing an ink jet head in which a pressure generating means forms a pressure chamber on the other surface of a diaphragm having a pattern formed on one surface, including the diaphragm, A first step of forming the pressure generating means on a substrate thicker than a thickness, and a wiring layer having wiring for supplying power to the pressure generating means are provided on the base of the pressure generating means. A second step of forming an upper layer having the base material and the wiring layer by forming on the forming surface, and the base material in the upper layer opposite to the forming surface of the pressure generating means The third step of forming the diaphragm by processing the diaphragm from the surface while leaving the thickness of the diaphragm is opposite to the formation surface of the pressure generating means in the diaphragm processed into a thin film Form a lower layer with the pressure chamber on the surface And having a fourth step of.

  The base material in the present invention includes a diaphragm. That is, the base material has a portion to be a diaphragm formed in the third step in its thickness. For this reason, the diaphragm in the present invention is in the form of a substrate thicker than the thickness of the diaphragm until the pressure chamber is formed by forming the lower layer in the fourth step.

  The thickness of the diaphragm processed into a thin film in the third step is preferably 1 to 18 μm. That the base material is thicker than the diaphragm is thicker than the design value of the thickness of the diaphragm formed in the third step, and has a thickness that does not hinder the handling of the base material itself. In general, it preferably has a thickness of 100 μm or more. Although the upper limit of the thickness is not particularly limited, it is preferably set to 200 μm or less from the viewpoint of suppressing the processing time and the waste of material since it is processed into a thin film in order to form the diaphragm in the third step.

Examples of the material for forming the diaphragm include Si, SiO ₂ , Si ₃ N ₄ , and SiC.

  In the present invention, until the diaphragm is processed in the third step, the diaphragm is in the form of a thick substrate, and in addition, the wiring layer is formed on the substrate in the second step. When the upper layer is produced and the diaphragm is processed from the base material in the third step by this wiring layer, and when the pressure chamber is formed in the fourth step after the diaphragm is processed, Sufficient support is provided. For this reason, even if the diaphragm processed from the base material in the third step is an extremely thin thin film that cannot be handled by itself, handling is facilitated by the support state provided by the second step. .

  After the diaphragm is formed by processing the base material into a thin film in the third step, in the fourth step, the lower layer having the pressure chamber can be directly joined to the diaphragm in the upper layer. Therefore, it is not necessary to dissolve the filler in the pressure chamber or to peel the diaphragm from the support base as in the conventional case. Therefore, there is no possibility that residues will remain in the pressure chamber and adversely affect the injection characteristics, and there is no need for a process of peeling the diaphragm, so the process can be simplified and a highly reliable ink jet head can be manufactured. Can do.

  In the present invention, in order to form the diaphragm, it is necessary to form a base material thicker than the diaphragm and then process the base material into a thin film. In the conventional method of forming the pressure generating means on the upper surface after forming the diaphragm on the pressure chamber, there is a concern that the pressure generating means of the diaphragm is applied in the process of attaching the pressure generating means or forming the spatter. Since the surface opposite to the formation surface is hollow, breakage that breaks through the diaphragm becomes a problem. In order to avoid this problem, sufficient rigidity can be obtained by providing a removable holding means in the pressure chamber, or by thickening the Si base material for making the diaphragm to make a part of Si a pressure chamber. It is necessary to make the structure to obtain. However, in the present invention, compared with the conventional method as described above, provisional holding means is not required, so there is no contamination in the pressure chamber, the range of selection of the side wall member of the diaphragm is widened, and more performance is achieved. A material excellent in cost performance can be selected, and a great effect can be obtained as compared with the conventional method.

  In the present invention, the pressure generating means uses a piezoelectric element that is an electromechanical conversion element that converts an electrical signal into mechanical energy. The material of the piezoelectric element is not particularly limited, and specific examples include PZT, PMN, PNN, PSN, PZN, PMN-PT, PSN-PT, PZN-PT and the like.

  A method for forming such a piezoelectric element on a substrate is preferably one that can form a piezoelectric element in a thin film on a substrate. For example, a film is formed directly on a substrate using a sputtering method, a CVD method, a printing method, or the like. After that, it is preferable to pattern into a desired shape. An upper electrode and a lower electrode are formed on the upper and lower surfaces of the piezoelectric element using an electrode material such as Al, Cu, Au, Pt, and Ni, and predetermined power is supplied to the upper electrode and the lower electrode from the wiring layer. Made. These upper electrode and lower electrode are also preferably formed by forming a film in the same manner as the piezoelectric element and patterning it into a desired shape.

  The wiring layer in the present invention has electrodes and wirings for supplying predetermined power necessary for driving the pressure generating means to the pressure generating means formed on the substrate. The wiring layer is integrated with the base material, so that in the third step, the diaphragm can be handled from the base material into a thin film and can be handled with respect to the diaphragm after being processed into a thin film. Any layer structure may be used as long as the state can be imparted.

  After the wiring layer is prepared in advance as a layer separate from the base material, it can be bonded to the formation surface of the pressure generating means in the base material, since it can be bonded after the inspection of the completion of the wiring layer, Although desirable from the viewpoint of yield, each layer may be sequentially stacked on the surface of the base material on which the pressure generating means is formed.

  In the present invention, the substrate may be a single layer or multiple layers. In the case of a base material composed of a single layer, the base material is preferably composed only of a single Si substrate. In this case, the diaphragm is made of thin film Si left after being processed into a thin film shape with the substrate remaining in a thickness that makes the diaphragm in the third step.

In the case of a base material composed of a plurality of layers, it is preferable that the base material has a thin film made of SiO ₂ having a thickness to be a diaphragm later formed on one surface of the Si substrate. In this case, since the thin film itself becomes a diaphragm later, in the first step, pressure generating means is formed on the thin film in the substrate. In the third step, the Si substrate portion of the base material is removed and only the thin film is left, so that the remaining thin film made of SiO ₂ becomes the diaphragm as it is.

Thus, when the base material has a Si substrate, the removal of Si can be performed by etching. As the etching process, a RIE (Reactive Ion Etching) method is preferable. The thickness of the diaphragm can be defined by the etching processing time. When Si is selectively etched on a multilayer substrate having a thin film made of SiO ₂ on a Si substrate, it is possible to reduce the etching rate of SiO ₂ by using a gas such as SF _6. By etching from the substrate side, it is easy to remove only the Si substrate while leaving a thin film made of SiO ₂ .

  The removal of Si from the base material can also be performed by polishing using a polishing apparatus used for polishing the Si substrate when manufacturing the semiconductor device.

  The lower layer in the present invention has a pressure chamber, and the diaphragm constitutes one wall surface of the pressure chamber by being bonded to the diaphragm formed by the third step. The lower layer includes a nozzle for ejecting ink by communicating the pressure chamber with the outside. In the present invention, the material for forming the lower layer is not particularly limited.

  In addition, since the lower layer is prepared in advance as a separate layer from the upper layer, and can be bonded to the diaphragm in the upper layer, it can be bonded after inspection of the completion of the lower layer. However, the layers may be sequentially stacked on the surface of the diaphragm in the upper layer opposite to the surface on which the pressure generating means is formed.

  The method for joining the lower layer to the diaphragm is not particularly limited, but the lower layer is composed of a glass substrate in which a through-hole serving as a pressure chamber is formed and a nozzle plate made of a Si substrate. It is preferable to integrally join the Si substrate processed into a thin film shape without using an adhesive. For such bonding, anodic bonding can be used.

  Next, a specific example of the manufacturing method according to the present invention will be described with reference to the drawings.

(First embodiment)
1 to 6 show steps of a method for manufacturing an ink jet head according to the first embodiment. Hereinafter, each step will be described.

(First step)
First, the Si substrate 10 (thickness: 100 [mu] m) on the entire surface of one surface of the thin film 11 (thickness: 2 [mu] m) made of SiO ₂ film was formed by a CVD (Chemical Vapor Deposition) method, a thin film of Si substrate 10 and the SiO ₂ 11 is formed (FIG. 1A).

  Next, a resist 12 is spin-coated on one surface of the thin film 11 of the base material 1 to form a film, and this is subjected to patterning by exposing and developing. By this patterning, the resist in a portion that will later become an ink supply channel is removed to form a removal portion 12a, and the thin film 11 is exposed only in the removal portion 12a (FIG. 1B).

Next, SiO ₂ is selectively etched from the upper surface of the resist 12 to the base material 1 by the RIE method, and the thin film 11 in the removal portion 12a is removed. Further, the resist 12 is peeled off by wet etching, and Si is selectively etched by RIE using SiO ₂ as a mask to form a through hole 13 (FIG. 1C).

Thereafter, a Ti film 14 (thickness: 0.02 μm) is formed on the thin film 11 of the substrate 1 by sputtering, and the lower electrode 15 (Pt film) is formed on the Ti film 14 by sputtering in the same manner. (Thickness: 0.10 μm) is formed (FIG. 1D). The Ti film 14 becomes an underlayer for the Pt film that is difficult to be directly laminated on SiO ₂ . After the formation of the lower electrode 15, the Ti film 14 and the lower electrode 15 are patterned.

  Next, a piezoelectric thin film 16 (thickness: 5 μm) made of PZT is formed on the upper surface of the lower electrode 15 by sputtering (FIG. 1E), and the piezoelectric thin film 16 is patterned to form a piezoelectric film on the lower electrode 15. The element 161 is manufactured (FIG. 1F).

  Further, a resist is applied and patterned on the substrate 1 after the piezoelectric element 161 is manufactured, and only the upper surface of the piezoelectric element 161 is exposed. Then, a Cu film (thickness: 0.5 μm) is formed, and the resist is formed. By removing, the upper electrode 17 made of a Cu film is formed only on the piezoelectric element 161 (FIG. 1G).

  In the first step described above, the thin film 11 that will later become a vibration plate constitutes the base material 1 by being laminated with the Si substrate 10 and has a sufficient thickness for handling. There is no hindrance to the film forming operation of the electrode 15 and the upper electrode 17.

(Second step)
<Fabrication of wiring layer>
First, a Si substrate 20 (thickness: 100 μm) is prepared separately from the base material 1, and an insulating film 21 (thickness: 2 μm) made of SiO _{2 is} formed on the entire surface of one surface by a CVD method. A metal film 22 (thickness: 1 μm) made of Al serving as an electrode member is formed on the upper surface of the insulating film 21 by sputtering (FIG. 2A).

  Next, a resist film is formed on the metal film 22, and the resist film is patterned by exposure and development, and a metal film other than a portion corresponding to each piezoelectric element 161 of the substrate 1 manufactured in the first step. 22 is exposed. Thereafter, etching is performed by RIE to remove the exposed metal film 22 and form an electrode 221 for electrical connection with the upper electrode of the piezoelectric element 161 (FIG. 2B).

Next, an insulating film 23 (thickness: 2 μm) made of SiO _{2 is} formed on the entire other surface of the Si substrate 20 by a CVD method (FIG. 2C). After the formation of the insulating film 23, a resist film is applied on the insulating film 23, and the resist film is patterned by exposure / development processing. The through hole communicating with the electrode 221 and the ink supply flow path are formed in the Si substrate 20. Etching is performed by an RIE method on the insulating film 23 where the through holes are to be formed, and the insulating film 23 is removed, thereby forming removal portions 23a and 23b. Further, the resist film formed on the insulating film 23 is removed by wet etching to expose the insulating film 23 (FIG. 2D).

Thereafter, the surface on which the removed portions 23a and 23b are formed is etched again by the RIE method. At this time, although the insulating film 23 made of SiO ₂ is also etched, the etching rate is slower than that of the Si substrate 20, so that the insulating film 23 serves as a mask, and is exposed to the removal portions 23 a and 23 b. The Si substrate 20 is removed first. Thereby, recesses 24a and 24b having a depth reaching the insulating film 21 formed on one surface of the Si substrate 20 are formed (FIG. 2E).

  After forming the recesses 24a and 24b, the insulating film 21 exposed at the bottoms of the recesses 24a and 24b is removed by further performing etching by the RIE method. Thus, the recesses 24a and 24b become through holes 241 and 242 that penetrate the Si substrate 20 and the insulating film 21, respectively. An electrode 221 faces the bottom of the through hole 242 (FIG. 2 (f)).

Next, an insulating film 25 (thickness: 2 μm) made of SiO _{2 is} formed again by the CVD method from the side opposite to the electrode 221. The insulating film 25 is also formed on the inner wall surface of the through hole 241, the inner wall surface of the through hole 242, and the electrode 221 facing the bottom of the through hole 242 (FIG. 2G).

After the formation of the insulating film 25, etching is performed from the surface of the insulating film 25 by the RIE method to remove the portion of the insulating film 25 formed on the electrode 221 facing the through hole 242 (FIG. 3 ( a)). Here, since the surface area per space in the through hole 242 is larger than the surface of the Si substrate 20, the Si substrate 20 is easier to form, and the film thickness of SiO ₂ in the through hole 242 is the Si substrate. Since it is thinner than 20, the through hole 242 opens faster than the Si substrate 20 is exposed by RIE. At this time, by performing anisotropic etching, the side wall of the through hole 242 is not etched, and the insulating film 25 of SiO ₂ is maintained.

  Thereafter, an unillustrated Ti film (thickness: 0.02 μm) serving as a base layer is formed on the insulating film 25 by sputtering, and a Cu film (thickness: 0.5 μm) is further formed on the Ti film by sputtering. Then, the Cu film is patterned by exposure / development processing using a resist, and the resist is removed from a portion that becomes a predetermined wiring pattern to expose the Cu film. Then, after Cu (thickness: 5 μm) is electroplated on the exposed Cu film, the resist is removed, the Cu film and the Ti film are etched, and the wiring 26 having a predetermined pattern made of Cu is formed on the insulating film 25. Form. The wiring 26 is electrically connected to the electrode 221 through the through hole 242 (FIG. 3B).

  Next, a photosensitive dry film 27 (thickness: 50 μm) is laminated on the side of the electrode 221 in the Si substrate 20, and patterning is performed by exposure / development processing to remove the dry film at the site of the through hole 241 and the electrode 221. (FIG. 3C). Thereafter, the contact point 28 is formed so as to protrude by applying a low melting point solder paste to the surface of the electrode 221. Thereby, the wiring layer 2 is produced (FIG. 3D).

<Preparation of upper layer>
Next, the dry film 27 side of the wiring layer 2 is arranged on the formation surface of the piezoelectric element 161 in the base material 1 manufactured in the first step, and the through hole 13 of the base material 1 and the through hole of the wiring layer 2 are arranged. 241, the contact portion 28 and the upper electrode 17 of the piezoelectric element 161 are aligned and overlapped with each other (FIG. 4A), and both are joined by heating and pressing to produce the upper layer 3. (FIG. 4B). By this heating and pressing, the dry film 27 functions as an adhesive layer and adheres to the base material 1, and the contact portion 28 melts and joins to the upper electrode 17 of the piezoelectric element 161 to obtain a reliable electrical connection. Further, the through hole 241 and the through hole 13 communicate with each other to form the ink supply flow path 31.

(Third step)
After producing the upper layer 3, the base material 1 in the upper layer 3 is etched by RIE from the surface opposite to the surface on which the piezoelectric element 161 is formed, and the Si substrate 10 constituting the base material 1 is removed. Then, the diaphragm is formed by the thin film 11 left after processing by thinly processing so as to leave only the thin film 11 (FIG. 5). Since the thin film 11 made of SiO ₂ has a slower etching rate than the Si substrate 10, only the thin film 11 can easily remain.

  Since the wiring layer 2 is bonded to one surface of the thin film 11 at the time of this etching process, the substrate 1 is processed into a thin film and the handling when processing to leave the thin film 11 is hindered. There is no.

  Further, the Si substrate 10 may be polished so as to leave only the thin film 11 by using a polishing apparatus instead of etching. In this case, the wiring layer 2 provides a sufficient support state for handling.

(Fourth process)
In the upper layer 3, the lower layer 4 is bonded to the surface of the thin film 11 that is a vibration plate opposite to the surface on which the piezoelectric element 161 is formed, and an ink jet head is manufactured. The lower layer 4 is formed by laminating a photosensitive dry film layer 42 (thickness: 100 μm) on a nozzle plate 41 (thickness: 150 μm) made of a Si substrate (FIG. 6A).

  In the nozzle plate 41, nozzles 411 are opened so as to correspond to the number of piezoelectric elements 161 and to be positioned below the piezoelectric elements 161.

  The dry film layer 42 serves as an adhesive layer for bonding the nozzle plate 41 to the thin film 11 of the upper layer 3, and after being laminated on the nozzle plate 41, by exposure and development processing, The pressure chambers 43 are formed so as to correspond to the number of piezoelectric elements 161 and to be positioned below the piezoelectric elements 161. The nozzle 411 is disposed at the bottom of the pressure chamber 43.

  The lower layer 4 is aligned below the upper layer 3 and then bonded to the upper layer 3 by the dry film layer 42 by heating and pressing. Thereby, the dry film layer 42 and the thin film 11 which is a diaphragm constitute the wall surface of the pressure chamber 43. The ink supply channel 31 communicates with the inside of the pressure chamber 43 (FIG. 6B).

  Here, since the photosensitive dry film layer 42 is used as a material constituting the wall surface of the pressure chamber 43, it is not necessary to use a separate substrate for forming the pressure chamber 43, and it can be easily performed by exposure / development processing. In addition to patterning, there is an advantage that the distance from the pressure chamber 43 to the nozzle 411 can be shortened and the flow path resistance can be reduced.

  A common ink chamber (not shown) is provided on the upper surface of the wiring layer 2. As a result, the ink in the common ink chamber is supplied to the pressure chamber 43 via the ink supply channel 31. The diameter of the inlet portion of the ink supply channel 31 is made narrower than the other portions to form a throttle portion (diameter 50 μm), so that the impedance for supplying ink and for forming droplets can be reduced. It has a function to adjust.

  In addition, the wiring 26 of the wiring layer 2 and the lower electrode 15 on the thin film 11 are electrically connected to a driving circuit (not shown). Electric power from the drive circuit is applied to the upper electrode 17 and the lower electrode 15 of the piezoelectric element 161 via the wiring 26, the electrode 221, and the contact portion 28, and drives the piezoelectric element 161 therebetween.

(Second Embodiment)
7 and 8 show the steps of the method of manufacturing the ink jet head according to the second embodiment. The second embodiment is a case where the base material 1 in the first embodiment is made of a single plate of the Si substrate 10. Since the first step and the second step are the same as those in the first embodiment except that the base material 1 is composed only of the Si substrate 10, detailed description thereof is omitted.

(Third step)
The upper layer 3 is formed by bonding the wiring layer 2 on the base material 1 composed only of the Si substrate 10 having the piezoelectric element 161, the lower electrode 15, and the upper electrode 17 (FIG. 7A), and thereafter The Si substrate 10 in the material 1 is processed into a thin film from the surface opposite to the surface on which the piezoelectric element 161 is formed, by etching using the RIE method or polishing using a polishing apparatus, leaving a thickness to be a vibration plate. Then, a Si thin film 101 (thickness: 5 μm) is formed (FIG. 7B). Here, this Si thin film 101 becomes a diaphragm as it is.

  During this etching process or polishing process, since the wiring layer 2 is bonded to one surface of the Si substrate 10, handling when forming the Si thin film 101 by processing the Si substrate 10 into a thin film is hindered. There is no.

(Fourth process)
The lower layer 4 is bonded to the upper layer 3 on the surface opposite to the surface on which the piezoelectric element 161 is formed in the Si thin film 101 which is a vibration plate, and an ink jet head is manufactured. The lower layer 4 is formed by laminating a glass substrate 44 (thickness: 150 μm) on a nozzle plate 41 (thickness: 150 μm) made of a Si substrate (FIG. 8).

  In the glass substrate 44, a pressure chamber 43 formed of a through hole is formed in advance by etching or sandblasting so as to correspond to the number of piezoelectric elements 161 and to be positioned below the piezoelectric elements 161.

  In the lower layer 4, the glass substrate 44 in which a through-hole serving as the pressure chamber 43 is formed and the nozzle plate 41 are aligned below the upper layer 3 so that the glass substrate 44 is in contact with the Si thin film 101 in the upper layer 3. Thereafter (FIG. 8A), the Si thin film 101 in the upper layer 3, the glass substrate 44, and the nozzle plate 41 made of the Si substrate are anodically bonded together without using an adhesive. Thus, the wall surface of the pressure chamber 43 is formed by the Si thin film 101 that is the vibration plate and the glass substrate 44. The ink supply channel 31 and the nozzle 411 communicate with the inside of the pressure chamber 43 (FIG. 8B).

  Also in this case, since the glass substrate 44 is used as the material constituting the side wall of the pressure chamber 43, the distance from the pressure chamber 43 to the nozzle 411 can be shortened, and the flow path resistance can be reduced.

(Third embodiment)
9 and 10 show the steps of the method of manufacturing the ink jet head according to the third embodiment. Since the third embodiment is the same as the first embodiment except that the lower layer 4 in the first embodiment is different, a detailed description of the first to third steps is omitted.

  9 and 10, the Ti film 14 is not shown.

(Fourth process)
The lower layer 4 is bonded to the upper layer 3 on the surface opposite to the surface on which the piezoelectric element 161 is formed in the thin film 11 which is a vibration plate, and an ink jet head is manufactured. The lower layer 4 is made of SUS (stainless steel), and is formed by laminating a pressure chamber substrate 46 (thickness: 150 μm) made of SUS on a nozzle plate 45 (thickness: 150 μm) made of SUS (FIG. 9).

  In the pressure chamber substrate 46, pressure chambers 43 each having a through-hole are formed in advance so as to correspond to the number of piezoelectric elements 161 and to be positioned below the piezoelectric elements 161.

  The lower layer 4 is formed by integrally bonding a pressure chamber substrate 46 having a through-hole serving as the pressure chamber 43 and the nozzle plate 45 by, for example, diffusion bonding, and then upper surface of the pressure chamber substrate 46 (bonding surface with the upper layer 3). A transfer adhesive layer 47 (thickness: 0.5 μm) is formed. The nozzle 451 faces the pressure chamber 43.

  The transfer adhesive layer 47 can be formed as follows, for example. First, the lower layer 4 with the pressure chamber substrate 46 down is disposed above the thin film-like transfer adhesive 471 (FIG. 10A), and the lower layer 4 is lowered to attach the pressure chamber substrate 46 to the transfer adhesive. It is made to contact 471 (FIG.10 (b)). Thereafter, when the lower layer 4 is raised, a part of the transfer adhesive 471 is transferred to the upper surface of the pressure chamber substrate 46 to form the transfer adhesive layer 47 (FIG. 10C).

  After the lower layer 4 having the transfer adhesive layer 47 is positioned below the upper layer 3 (FIG. 9A), it is heated and pressurized and joined to the upper layer 3 by the transfer adhesive layer 47. Thereby, the wall surface of the pressure chamber 43 is formed by the thin film 11 which is a vibration plate and the pressure chamber substrate 46. The ink supply channel 31 communicates with the inside of the pressure chamber 43 (FIG. 9B).

  Also in this case, since the pressure chamber substrate 46 made of SUS is used as the material constituting the side wall of the pressure chamber 43, the distance from the pressure chamber 43 to the nozzle 451 can be shortened, and the flow path resistance can be reduced.

DESCRIPTION OF SYMBOLS 1 Base material 10 Si substrate 11 Thin film 12 Resist 12a Removal part 13 Through-hole 14 Ti film 15 Lower electrode 16 Piezoelectric thin film 161 Piezoelectric element 17 Upper electrode 2 Wiring layer 20 Si substrate 21 Insulating film 22 Metal film 221 Electrode 23 Insulating film 23a, 23b Removal part 24a, 24b Concave part 241, 242 Through hole 25 Insulating film 26 Wiring 27 Dry film 28 Contact part 3 Upper layer 31 Ink supply flow path 4 Lower layer 41 Nozzle plate 411 Nozzle 42 Dry film layer 43 Pressure chamber 44 Glass substrate 45 Nozzle plate 451 Nozzle 46 Pressure chamber substrate 47 Transfer adhesive layer 471 Transfer adhesive

Claims (6)

A pressure generating means is a method for manufacturing an ink jet head in which a pressure chamber is formed on the other surface of a diaphragm patterned on one surface,
A first step of forming the pressure generating means on a base material that includes the diaphragm and is thicker than the thickness of the diaphragm;
An upper layer having the substrate and the wiring layer is formed by forming a wiring layer having a wiring for supplying power to the pressure generating unit on a formation surface of the pressure generating unit in the substrate. A second step to produce;
A third step of forming the diaphragm by processing the base material in the upper layer into a thin film shape, leaving a thickness of the diaphragm from a surface opposite to a surface on which the pressure generating unit is formed;
A method of manufacturing an ink jet head, comprising: a fourth step of forming a lower layer having the pressure chamber on a surface opposite to a surface on which the pressure generating unit is formed in the diaphragm processed into a thin film. . In the base material, a thin film made of SiO ₂ having a thickness to be the diaphragm is formed on one surface of a Si substrate,
The first step forms the pressure generating means on the thin film of the base material,
2. The method of manufacturing an ink jet head according to claim 1, wherein the third step is processed into a thin film by removing the Si substrate while leaving the thin film of the base material. 3. The base material is composed only of a Si substrate,
2. The method of manufacturing an ink jet head according to claim 1, wherein in the third step, the Si substrate is processed into a thin film by removing the Si substrate while leaving a thickness to be the vibration plate.   In the fourth step, the lower layer includes a glass substrate in which a through-hole serving as the pressure chamber is formed and a nozzle plate made of a Si substrate, and an adhesive is applied to the Si substrate processed into the thin film shape. 4. The method of manufacturing an ink-jet head according to claim 3, wherein the ink-jet head is integrally joined without being used.   The method of manufacturing an ink jet head according to claim 2, wherein the removal of the Si substrate is an etching process.   The method of manufacturing an ink jet head according to claim 2, wherein the removal of the Si substrate is a polishing process.