JP4591005B2 - Method for manufacturing liquid jet head - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid ejecting head that ejects liquid, and more particularly, to a method for manufacturing an ink jet recording head that ejects ink as a liquid.

  As an ink jet recording head that is a liquid ejecting head, for example, a flow path forming substrate in which a pressure generation chamber communicating with a nozzle opening and a communication portion communicating with the pressure generation chamber are formed, and one of the flow path forming substrates is provided. A piezoelectric element formed on the surface side, and a reservoir forming substrate having a reservoir portion that is joined to the surface of the flow path forming substrate on the piezoelectric element side and forms a part of the reservoir together with the communicating portion. There is one in which a reservoir is formed by communicating a reservoir and a communicating portion through a penetrating portion that penetrates a laminated film provided on a plate (see, for example, Patent Document 1). Specifically, a portion facing the communication portion (reservoir portion) of the diaphragm and the laminated film is mechanically punched to form a through portion, thereby connecting the reservoir portion and the communication portion.

  However, when the penetrating portion is formed by such mechanical processing, there is a problem that foreign matter such as machining residue is generated and the foreign matter enters a flow path such as a pressure generating chamber, which causes discharge failure and the like. In addition, after forming the penetration part, for example, by performing cleaning or the like, foreign matters such as processing residue can be removed to some extent, but it is difficult to remove completely. Further, when the penetrating portion is mechanically processed, a crack or the like is generated around the penetrating portion, and there is a problem that a discharge failure occurs due to the occurrence of the crack. That is, when ink is filled in a cracked state and discharged from the nozzle opening, there is a problem in that a broken piece falls off from the cracked portion, and the broken piece is clogged in the nozzle opening to cause a discharge failure.

  In order to solve such a problem, Patent Document 1 described above discloses a structure in which a laminated film is fixed by a coating film made of a resin material to prevent generation of foreign matters. By adopting this structure, the generation of foreign matter may be suppressed to some extent, but it is difficult to completely prevent ejection failure due to foreign matter.

  Such a problem exists not only in a method for manufacturing an ink jet recording head that discharges ink, but also in a method for manufacturing another liquid ejecting head that discharges liquid other than ink.

JP 2003-159801 A (FIGS. 7-8)

  In view of such circumstances, it is an object of the present invention to provide a method of manufacturing a liquid ejecting head that can reliably prevent ejection failure such as nozzle clogging due to foreign matter.

A first aspect of the present invention that solves the above problem is a flow path forming substrate that includes a pressure generation chamber that is formed of a silicon substrate and communicates with a nozzle opening that ejects liquid, and a communication portion that communicates with the pressure generation chamber. Forming a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode on one surface side through a vibration plate and removing the vibration plate in a region serving as the communication portion to form a through hole; and an adhesion layer The lead electrode is formed from the piezoelectric element and is formed of the contact layer and the metal layer, and the lead electrode is a discontinuous metal layer in a region corresponding to the through hole. Forming at least a part of the flow path forming substrate, and forming the reservoir forming substrate formed with the reservoir portion that forms a part of the reservoir in communication with the communication portion after the discontinuous metal layer is formed. Bonded to the side A step of fixing through, the rear fixing reservoir forming substrate and with said passage forming substrate, the passage forming substrate in a state where the through hole is sealed with a film containing at least the discontinuous metal layer other Forming the communicating portion by wet etching from the side of the surface, and removing at least the metal layer constituting the discontinuous metal layer by wet etching to allow the reservoir portion and the communicating portion to communicate with each other. a step that form a reservoir, in the manufacturing method of the liquid ejecting head, characterized by comprising a step of forming a liquid protective film made of a material having a liquid resistant to at least the inner surface of the reservoir.
In such a first aspect, when forming the reservoir, foreign matter such as machining residue is not generated, and thus ejection failure such as nozzle clogging due to machining residue or the like is reliably prevented. Further, it is possible to prevent the etching solution when etching the flow path forming substrate from flowing into the reservoir forming substrate side through the through hole, and it is possible to prevent the reservoir forming substrate from being damaged by the etching solution. Moreover, a liquid protective film can be favorably formed by removing the metal layer which comprises a discontinuous metal layer completely.

According to a second aspect of the present invention, in the first aspect, the liquid jet head manufacturing method is characterized in that the through hole is sealed only with the discontinuous metal layer.
In the second aspect, since the through hole is reliably sealed, the communication portion and the like can be satisfactorily formed by etching.

According to a third aspect of the present invention, in the first aspect, the discontinuous metal layer is formed in a region facing the through hole, and the through hole is formed by a film including the discontinuous metal layer and the adhesive layer. The method of manufacturing a liquid jet head is characterized in that the liquid jet head is sealed.
In the third aspect, at least the adhesion layer and the metal layer constituting the discontinuous metal layer are surely removed by etching.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the diaphragm includes an elastic film made of silicon dioxide, and the reservoir forming substrate is formed on the elastic film around the discontinuous metal layer. The liquid jet head manufacturing method is characterized in that the liquid jet head is directly bonded.
In the fourth aspect, the adhesive strength between the flow path forming substrate and the reservoir forming substrate is improved.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the metal layer is made of gold (Au) and the adhesion layer is made of titanium tungsten (TiW). It is in the manufacturing method.
In the fifth aspect, the lead electrode can be satisfactorily formed and the through hole can be reliably sealed.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view showing an ink jet recording head manufactured by a manufacturing method according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of FIG. As shown in the figure, the flow path forming substrate 10 is formed of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is previously formed of silicon dioxide by thermal oxidation to a thickness of 0.5 to 2 μm. The elastic film 50 is formed.

  A plurality of pressure generating chambers 12 are arranged in parallel in the width direction of the flow path forming substrate 10. Further, a communication portion 13 is formed in a region outside the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10, and the communication portion 13 and each pressure generation chamber 12 are provided for each pressure generation chamber 12. Communication is made via a path 14. The communication portion 13 constitutes a part of a reservoir 100 that communicates with a reservoir portion 31 of a reservoir forming substrate 30 described later and serves as a common ink chamber for the pressure generation chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

  Here, on the inner wall surfaces of the pressure generation chamber 12, the communication portion 13, and the ink supply path 14 of the flow path forming substrate 10, a material having liquid resistance, for example, in this embodiment, etching resistance to alkaline ink ( A liquid protective film 15 made of a material having ink resistance is provided.

The material of the liquid protective film 15 is not particularly limited as long as it is a material having ink resistance, and examples thereof include tantalum oxide, zirconium oxide, nickel, and chromium. For example, in this embodiment, tantalum pentoxide (Ta ₂ O ₅ ) is used as the material of the liquid protective film 15. In the present embodiment, the liquid protective film 15 is provided on the surface of the flow path forming substrate 10 on the side where the pressure generating chambers 12 and the like are opened, that is, the bonding surface to which the nozzle plate 20 is bonded. In such a region, the ink does not substantially contact, and thus the liquid protective film 15 may not be provided.

Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the end of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive. Or a heat-welded film or the like. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], glass ceramics, silicon It consists of a single crystal substrate or stainless steel.

  On the other hand, as described above, the elastic film 50 having a thickness of, for example, about 1.0 μm is formed on the surface opposite to the opening surface of the flow path forming substrate 10. An insulating film 51 having a thickness of, for example, about 0.4 μm is formed. Further, on the insulator film 51, a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0 The upper electrode film 80 having a thickness of 0.05 μm is laminated by a process described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.

  In addition, a lead electrode 90 is drawn out from the upper electrode film 80 of each piezoelectric element 300, and a voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90. The lead electrode 90 includes an adhesion layer 91 made of, for example, titanium tungsten (TiW), and a metal layer 92 formed on the adhesion layer 91 and made of, for example, gold (Au). Further, as will be described in detail later, the adhesion layer 91 constituting the lead electrode 90 remains on the elastic film 50 and the insulator film 51 in the region corresponding to the peripheral edge of the opening of the communication portion 13. The adhesion layer 91 remaining at the peripheral edge of the communication portion 13 remains without being continuous with the lead electrode 90.

  On the surface of the flow path forming substrate 10 on the piezoelectric element 300 side, a reservoir forming substrate 30 having a reservoir portion 31 constituting at least a part of the reservoir 100 is an adhesive layer made of, for example, an epoxy-based adhesive. 35 is bonded. The reservoir portion 31 of the reservoir forming substrate 30 communicates with the communication portion 13 through through holes 50 a and 51 a provided in the elastic film 50 and the insulator film 51, and the reservoir 100 is formed by the reservoir portion 31 and the communication portion 13. Has been.

  In addition, a piezoelectric element holding portion 32 is provided in a region facing the piezoelectric element 300 of the reservoir forming substrate 30. Since the piezoelectric element 300 is formed in the piezoelectric element holding portion 32, the piezoelectric element 300 is protected in a state hardly affected by the external environment. In addition, the piezoelectric element holding | maintenance part 32 may be sealed and does not need to be sealed. Examples of the material of the reservoir forming substrate 30 include glass, ceramic material, metal, resin, and the like, but it is preferable that the reservoir forming substrate 30 be formed of a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. In this embodiment, the silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  A connection wiring 200 formed in a predetermined pattern is provided on the reservoir forming substrate 30, and a driving IC 210 for driving the piezoelectric element 300 is mounted on the connection wiring 200. Then, the leading end portion of each lead electrode 90 drawn from each piezoelectric element 300 to the outside of the piezoelectric element holding portion 32 and the driving IC 210 are electrically connected via the driving wiring 220.

  Further, a compliance substrate 40 composed of a sealing film 41 and a fixing plate 42 is bonded onto a region corresponding to the reservoir portion 31 of the reservoir forming substrate 30. The sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm). Yes. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head of this embodiment, ink is taken in from an external ink supply means (not shown), filled with ink from the reservoir 100 to the nozzle opening 21, and then subjected to pressure according to a recording signal from the driving IC 210. By applying a voltage between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the generation chamber 12 to bend and deform the piezoelectric element 300 and the diaphragm, the pressure in each pressure generation chamber 12 is increased. Ink is ejected from the opening 21.

  Hereinafter, a method for manufacturing such an ink jet recording head will be described with reference to FIGS. 3 to 6 are cross-sectional views of the pressure generating chamber 12 in the longitudinal direction. First, as shown in FIG. 3A, a channel forming substrate wafer 110 which is a silicon wafer is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film 52 constituting an elastic film 50 is formed on the surface thereof. To do. In this embodiment, a silicon wafer having a relatively thick film thickness of about 625 μm and a high rigidity is used as the flow path forming substrate wafer 110.

Next, as shown in FIG. 3B, an insulator film 51 made of zirconium oxide is formed on the elastic film 50 (silicon dioxide film 52). Specifically, after a zirconium (Zr) layer is formed on the elastic film 50 (silicon dioxide film 52) by, for example, sputtering, the zirconium layer is thermally oxidized in a diffusion furnace at 500 to 1200 ° C., for example. Thus, the insulator film 51 made of zirconium oxide (ZrO ₂ ) is formed.

  Next, as shown in FIG. 3C, for example, a lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 51, and then the lower electrode film 60 is patterned into a predetermined shape. Next, as shown in FIG. 4A, a piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) or the like, and an upper electrode film 80 made of, for example, iridium are formed on the entire surface of the flow path forming substrate wafer 110. Then, the piezoelectric layer 300 and the upper electrode film 80 are patterned in a region facing each pressure generating chamber 12 to form the piezoelectric element 300. In addition, after the piezoelectric element 300 is formed, the insulator film 51 and the elastic film 50 are patterned, and the insulator film 51 and the elastic film 50 in a region where a communication portion (not shown) of the flow path forming substrate wafer 110 is formed. To penetrate. That is, the insulating film 51 is etched to form the through hole 51a, and the elastic film 50 is further etched to form the through hole 50a. In the present embodiment, the through hole 51 a of the insulator film 51 is formed so that the opening area is larger than the through hole 50 a of the elastic film 50. Of course, these through holes 50a and 51a may be formed in the same size.

Here, as a material of the piezoelectric layer 70 constituting the piezoelectric element 300, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT), niobium, nickel, magnesium, bismuth, yttrium or the like is used. A relaxor ferroelectric or the like to which any of the above metals is added is used. The composition may be appropriately selected in consideration of the characteristics, application, etc. of the piezoelectric element 300. For example, PbTiO ₃ (PT), PbZrO ₃ (PZ), Pb (Zr _x Ti _1-x ) O ₃ (PZT) ), Pb (Mg _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PMN-PT), Pb (Zn _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ (PZN-PT), Pb (Ni ₁ ) _{/ 3 Nb 2/3) O 3 -PbTiO} 3 (PNN-PT), Pb (In 1/2 Nb 1/2) O 3 -PbTiO 3 (PIN-PT), Pb (Sc 1/3 Ta 1/2 _{) O 3 -PbTiO 3 (PST-} PT), Pb (Sc 1/3 Nb 1/2) O 3 -PbTiO 3 (PSN-PT), BiScO 3 -PbTiO 3 (BS-PT), BiYbO 3 -PbTiO 3 (BY PT), and the like.

  The method for forming the piezoelectric layer 70 is not particularly limited. For example, in this embodiment, a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst is applied, dried, gelled, and further fired at a high temperature. The piezoelectric layer 70 was formed by using a so-called sol-gel method for obtaining a piezoelectric layer 70 made of an oxide.

  Next, as shown in FIG. 4B, lead electrodes 90 are formed. Specifically, first, an adhesion layer 91 made of, for example, titanium tungsten (TiW) is formed over the entire surface of the flow path forming substrate wafer 110, and, for example, gold (Au) is made on this adhesion layer 91. A metal layer 92 is formed. Then, a mask pattern (not shown) made of, for example, a resist is formed on the metal layer 92, and the metal layer 92 and the adhesion layer 91 are patterned for each piezoelectric element 300 through the mask pattern, thereby leading to the lead electrode. 90 is formed.

  At this time, the adhesion layer 91 and the metal layer 92 in the region corresponding to the through holes 50 a and 51 a are left discontinuous with the lead electrode 90. That is, the discontinuous metal layer 95 including the adhesion layer 91 discontinuous with the lead electrode 90 and the metal layer 92 is formed in at least a part of the region facing the through holes 50a and 51a. For example, in this embodiment, the discontinuous metal layer 95 is formed so as to cover the through holes 50a and 51a, and the through holes 50a and 51a are sealed only by the discontinuous metal layer 95. The discontinuous metal layer 95 plays a role of regulating the spread of etching when the pressure generating chamber 12 and the like are formed in the flow path forming substrate wafer 110 by etching in a process described later.

  Next, as shown in FIG. 4C, the reservoir forming substrate wafer 130 is fixed onto the flow path forming substrate wafer 110 via the adhesive layer 35. Here, the reservoir forming substrate wafer 130 is preliminarily formed with a reservoir portion 31, a piezoelectric element holding portion 32, and the like, and the above-described connection wiring 200 is formed in advance on the reservoir forming substrate wafer 130. Yes. The reservoir forming substrate wafer 130 is, for example, a silicon wafer having a thickness of about 400 μm, and the rigidity of the flow path forming substrate wafer 110 is significantly improved by bonding the reservoir forming substrate wafer 130. Become.

  Next, as shown in FIG. 5A, after the flow path forming substrate wafer 110 is polished to a certain thickness, the flow path forming substrate wafer 110 is further etched by fluoric nitric acid to thereby remove the flow path forming substrate wafer 110 from the predetermined thickness. Make it thick. For example, in this embodiment, the flow path forming substrate wafer 110 is processed to have a thickness of about 70 μm by polishing and wet etching. Next, as shown in FIG. 5B, a mask film 53 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape.

  Then, as shown in FIG. 5C, the flow path forming substrate wafer 110 is anisotropically etched (wet etching) through the mask film 53, and the pressure generating chamber 12 is applied to the flow path forming substrate wafer 110. The communication part 13 and the ink supply path 14 are formed. That is, in a state where the through holes 50a and 51a are sealed with the discontinuous metal layer 95, the flow path forming substrate wafer 110 is etched with an etching solution such as an aqueous potassium hydroxide (KOH) solution. Then, by etching the flow path forming substrate wafer 110 until the elastic film 50 and the discontinuous metal layer 95 are exposed, the pressure generating chamber 12, the communication portion 13, and the ink supply path 14 are formed simultaneously.

  At this time, since the through holes 50a and 51a are sealed by the discontinuous metal layer 95 including the adhesion layer 91 and the metal layer 92, the etching solution is supplied to the reservoir forming substrate wafer 130 side through the through holes 50a and 51a. There is no inflow. As a result, the etchant does not adhere to the connection wiring 200 provided on the surface of the reservoir forming substrate wafer 130, and the occurrence of defects such as disconnection can be prevented. Further, there is no possibility that the etchant enters the reservoir portion 31 and the reservoir forming substrate wafer 130 is etched.

  When forming such a pressure generating chamber 12 or the like, the surface of the reservoir forming substrate wafer 130 opposite to the flow path forming substrate wafer 110 side is made of a material having alkali resistance, such as PPS (polyphenylene sulfide). ), PPTA (polyparaphenylene terephthalamide) or the like may be further sealed. Thereby, defects such as disconnection of wiring provided on the surface of the reservoir forming substrate wafer 130 can be more reliably prevented.

  Next, as shown in FIG. 6, the discontinuous metal layer 95 composed of the adhesion layer 91 and the metal layer 92 is removed by wet etching, and the communication portion 13 and the reservoir portion 31 are communicated with each other through the through holes 50a and 51a. Thus, the reservoir 100 is formed. At this time, in the present invention, the metal layer 92 constituting the discontinuous metal layer 95 is completely removed. Specifically, first, as shown in FIG. 6A, the adhesion layer 91 in a region facing the through hole 50a is removed by wet etching to form a through portion 91a. Then, as shown in FIG. 6B, the metal layer 92 is completely removed by wet-etching the metal layer 92 through the through portion 91a of the adhesion layer 91. As a result, only the adhesion layer 91 remains at the peripheral edge of the communication portion 13.

  The metal layer 92 can be removed relatively easily by adjusting the etching time. That is, the metal layer 92 is etched in the thickness direction and gradually (side-etched) in the surface direction. For this reason, the metal layer 92 is completely removed by adjusting the etching time to be longer.

  After the metal layer 92 is completely removed in this way, as shown in FIG. 6C, the mask film 53 on the surface of the flow path forming substrate wafer 110 is removed, and the inner surface of the reservoir 100 and the like is protected against the inner surface. A liquid protective film 15 made of a material having liquidity (ink resistance), for example, tantalum pentoxide is formed by, for example, a CVD method.

  At this time, since the metal layer 92 of the discontinuous metal layer 95 is completely removed, the liquid protective film 15 can be satisfactorily formed on the inner surface of the reservoir 100 or the like. That is, when the adhesion layer 91 and the metal layer 92 constituting the discontinuous metal layer 95 are left in the peripheral portion of the through hole 50a, electric contact is caused between the metal layer 92 and the liquid protective film 15 formed on the surface thereof. There is a risk that the portion where the electric contact has occurred will be eroded by the ink. However, by completely removing the metal layer 92 constituting the discontinuous metal layer 95 as described above, the occurrence of electrical contact can be prevented, and an ink jet recording head having excellent durability can be manufactured.

  After the liquid protective film 15 is formed, the driving IC 210 is mounted on the connection wiring 200 formed on the reservoir forming substrate wafer 130, and the driving IC 210 and the lead electrode 90 are connected by the driving wiring 220. Thereafter, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the reservoir forming substrate wafer 130 are removed by cutting, for example, by dicing. The nozzle plate 20 having the nozzle openings 21 is bonded to the surface of the flow path forming substrate wafer 110 opposite to the reservoir forming substrate wafer 130, and the compliance substrate 40 is attached to the reservoir forming substrate wafer 130. The ink jet recording head having the above-described structure is manufactured by bonding and dividing the flow path forming substrate wafer 110 and the like into a single chip size flow path forming substrate 10 as shown in FIG.

  As described above, in the present embodiment, the through holes 50 a and 51 a are sealed with the discontinuous metal layer 95 including the adhesion layer 91 and the metal layer 92 that are the same layer as the lead electrode 90. Is finally removed by etching, so that the reservoir portion 31 and the communication portion 13 are made to communicate with each other. For this reason, unlike conventional mechanical processing, foreign matter such as processing residue does not occur. Accordingly, it is possible to reliably prevent the machining residue from remaining in the ink flow paths such as the pressure generation chamber 12 and the communication portion 13 and the occurrence of defective discharge such as nozzle clogging due to the remaining machining residue.

  Further, as described above, since the metal layer 92 of the discontinuous metal layer 95 is completely removed, the liquid protective film 15 can be satisfactorily formed on the inner surface of the reservoir 100 or the like.

(Embodiment 2)
FIG. 7 is a cross-sectional view illustrating a manufacturing process of the ink jet recording head according to the second embodiment. In this embodiment, the through holes 50a and 51a are sealed by the discontinuous metal layer 95 and the adhesive layer 35 for bonding the reservoir forming substrate wafer 130 and the flow path forming substrate wafer 110. Except for this, it is the same as in the first embodiment.

  That is, in this embodiment, as shown in FIG. 7A, the through hole 51 a of the insulator film 51 is formed larger than the through hole 50 a of the elastic film 50 and faces the through hole 51 a of the insulator film 51. A discontinuous metal layer 95 is formed in the region. Thereafter, the reservoir forming substrate wafer 130 is fixed to the flow path forming substrate wafer 110 via the adhesive layer 35, and the through holes 50a and 51a are sealed by the adhesive layer 35 and the discontinuous metal layer 95. did. Then, the flow path forming substrate wafer 110 is etched in a state in which the through holes 50a and 51a are sealed by the discontinuous metal layer 95 and the adhesive layer 35 in this way, so that the pressure generating chamber 12, the communication portion 13, etc. To form.

  Of course, even in such a configuration, as shown in FIG. 7B, the metal layer 91 constituting the discontinuous metal layer 95 is completely removed, and a reservoir composed of the communication portion 13 and the reservoir portion 31 is obtained. 100 is formed.

  In such a manufacturing method of this embodiment, since the through holes 50a and 51a are sealed with the discontinuous metal layer 95 and the adhesive layer 35, the elastic material made of silicon dioxide is formed around the discontinuous metal layer 95. There is a region where the film 50 and the reservoir forming substrate wafer 130 are directly bonded. As a result, the bonding strength between the flow path forming substrate wafer 110 and the reservoir forming substrate wafer 130 can be improved. Of course, in such an embodiment, it is needless to say that the same effects as those of the first embodiment can be obtained.

  In this embodiment, the discontinuous metal layer 95 is continuously provided up to the elastic film 50 outside the through hole 50a. However, the present invention is not limited to this. For example, as shown in FIG. 8A, the discontinuous metal layer 95 may be formed only in a region facing the through hole 50a. Even when the discontinuous metal layer 95 is formed in this way, the through holes 50a and 51a are surely sealed by the discontinuous metal layer 95 and the adhesive layer 35, so that the pressure generating chamber 12, the communication portion 13 and the like are etched. Can be formed satisfactorily.

  When the discontinuous metal layer 95 is formed only in the region facing the through hole 50a as described above, both the metal layer 92 and the adhesion layer 91 are completely removed as shown in FIG. 8B. Thus, the reservoir 100 composed of the communication portion 13 and the reservoir portion 31 is formed.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the through holes 50a and 51a are formed after the piezoelectric element 300 is formed. Conversely, the through holes 50a and 51a are formed before the piezoelectric element 300 is formed. Good. In the above-described embodiments, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention broadly applies to all liquid ejecting heads and ejects liquids other than ink. Of course, the present invention can also be applied to a method of manufacturing a liquid jet head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (surface emitting displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. 5 is a cross-sectional view showing a manufacturing process according to Embodiment 1. FIG. 5 is a cross-sectional view showing a manufacturing process according to Embodiment 1. FIG. 5 is a cross-sectional view showing a manufacturing process according to Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view showing a manufacturing process according to the first embodiment. 6 is an enlarged cross-sectional view showing a manufacturing process according to Embodiment 2. FIG. 12 is an enlarged cross-sectional view showing another example of the manufacturing process according to Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 15 Liquid protective film, 20 Nozzle plate, 21 Nozzle opening, 30 Reservoir formation board | substrate, 31 Reservoir part, 32 Piezoelectric element holding | maintenance part, 35 Adhesion layer, 40 Compliance board | substrate, 50 Elastic film , 51 insulator film, 50a, 51a through hole, 60 lower electrode film, 70 piezoelectric layer, 80 upper electrode film, 90 lead electrode, 91 adhesion layer, 92 metal layer, 95 discontinuous metal layer, 100 reservoir, 110 flow Wafer for path forming substrate, 130 Wafer for reservoir forming substrate, 200 Connection wiring, 205 Metal layer, 210 Driving IC, 220 Driving wiring, 230 Protective film, 300 Piezoelectric element

Claims (5)

A lower electrode and a piezoelectric body via a vibration plate on one side of a flow path forming substrate in which a pressure generating chamber made of a silicon substrate and communicating with a nozzle opening for ejecting liquid and a communicating portion communicating with the pressure generating chamber are formed Forming a piezoelectric element comprising a layer and an upper electrode and removing the diaphragm in the region serving as the communicating portion to form a through hole; and a lead electrode drawn from the piezoelectric element comprising an adhesion layer and a metal layer And forming the discontinuous metal layer in at least part of the region corresponding to the through hole, and the discontinuous metal layer comprising the adhesion layer and the metal layer, Forming a reservoir forming substrate in which a reservoir portion composing a part of the reservoir in communication with the communication portion is formed on the one surface side of the flow path forming substrate via an adhesive layer; The reserve After the formation substrate is fixed to said passage forming substrate, the communicating by wet etching the passage forming substrate from the other surface side in a state in which the through hole is sealed with a film containing at least the discontinuous metal layer forming a part, comprising the steps you forming the reservoir at least the metal layer constituting the discontinuous metal layer communicates with said communicating portion and the reservoir portion is completely removed by wet etching, at least Forming a liquid protective film made of a liquid-resistant material on the inner surface of the reservoir. The method of manufacturing a liquid jet head according to claim 1, wherein the through hole is sealed only with the discontinuous metal layer. 2. The discontinuous metal layer according to claim 1, wherein the discontinuous metal layer is formed in a region facing the through hole, and the through hole is sealed with a film including the discontinuous metal layer and the adhesive layer. A method for manufacturing a liquid jet head. 4. The diaphragm according to claim 1, wherein the diaphragm includes an elastic film made of silicon dioxide, and the reservoir forming substrate is directly bonded to the elastic film around the discontinuous metal layer. A method for manufacturing a liquid jet head. 5. The method of manufacturing a liquid jet head according to claim 1, wherein the metal layer is made of gold (Au), and the adhesion layer is made of titanium tungsten (TiW).

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