JP2006181826A - Liquid jet head and liquid jet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet head which prevents cracks occurring in a vibrating plate due to the concentration of stress and a liquid jet device equipped with the liquid jet head. <P>SOLUTION: The liquid jet head comprises: a channel forming substrate 10 in which a pressure generation chamber communicating with nozzle openings to jet liquids is formed; a vibrating plate having at least a first elastic film 50 provided on one side of the channel forming substrate 10 and made of a silicon dioxide, and a second elastic film 55 provided on the first elastic film 50 and made of a material which is tougher than the first elastic film; a piezoelectric element 300 provided on the vibrating plate and made up of a lower electrode 60, a piezoelectric body layer 70 and an upper electrode 80; a protective substrate 30 having a piezoelectric element holding portion 31 joined onto the vibrating plate of the channel forming substrate 10 and protecting the piezoelectric element 300; and a first elastic film separation portion 51 to separate the first elastic film 50 forming the vibrating plate along the edge portion of the piezoelectric element holding portion 31 at least in the inside of the edge portion of the piezoelectric element holding portion 31. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject liquid droplets, and in particular, pressurizes ink supplied to a pressure generating chamber that communicates with a nozzle opening that ejects ink droplets by a piezoelectric element. The present invention relates to an ink jet recording head and an ink jet recording apparatus that discharge ink droplets.

  A part of the pressure generation chamber communicating with the nozzle opening for discharging ink droplets is constituted by a vibration plate, and the vibration plate is deformed by a piezoelectric element to pressurize the ink in the pressure generation chamber to discharge ink droplets from the nozzle opening. Two types of ink jet recording heads have been put into practical use: those using a longitudinal vibration mode piezoelectric actuator that extends and contracts in the axial direction of the piezoelectric element, and those using a flexural vibration mode piezoelectric actuator. As an example of using an actuator in a flexural vibration mode, for example, a uniform piezoelectric material layer is formed over the entire surface of the diaphragm by a film forming technique, and this piezoelectric material layer is formed into a pressure generating chamber by a lithography method. A device in which a piezoelectric element is formed so as to be cut into a corresponding shape and independent for each pressure generating chamber is known.

  Further, such a piezoelectric element has a problem that it is easily destroyed due to an external environment such as moisture. Such problems are more likely to occur as the layers constituting the piezoelectric element become thinner. For this reason, for example, a bonding substrate having a piezoelectric element holding portion is bonded to a flow path forming substrate in which a pressure generating chamber is formed, and a plurality of piezoelectric elements arranged in parallel in the piezoelectric element holding portion are sealed. There are some (see, for example, Patent Document 1).

  In such a structure in which the bonding substrate is bonded to the flow path forming substrate, each piezoelectric element can be prevented from being broken. However, there is a problem that cracks, cracks, etc. occur in the diaphragm in the vicinity of the edge of the piezoelectric element holding portion, and the cracks progress to the piezoelectric element side over time, and eventually the piezoelectric element is destroyed. . That is, in the structure in which the bonding substrate is bonded to the flow path forming substrate in this way, stress is also generated due to a difference in thermal expansion coefficient between the flow path forming substrate and each layer formed on the flow path forming substrate. When a bonding substrate is bonded to the flow path forming substrate, a large stress is concentrated on a region facing the edge of the piezoelectric element holding portion. In addition, for example, the region outside the region where the piezoelectric element holding portion is provided has higher rigidity, so that the flow channel forming substrate (vibration plate) is used when the bonding substrate and the flow channel forming substrate are bonded. Is deformed, and stress is concentrated in a region corresponding to the edge of the piezoelectric element holding portion. For this reason, the diaphragm in the region corresponding to the edge portion of the piezoelectric element holding portion has a problem that cracks, cracks, and the like are generated due to such stress concentration. In particular, such a problem is likely to occur when at least a part of the diaphragm is formed of a fragile material such as silicon dioxide. Such a problem exists not only in the ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject liquid other than ink.

JP 2002-113857 A (Claims etc.)

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head that can prevent cracks and the like from being generated in a diaphragm due to stress concentration, and a liquid ejecting apparatus including the liquid ejecting head. .

According to a first aspect of the present invention for solving the above-described problems, a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, and a carbon dioxide provided on one side of the flow path forming substrate. A diaphragm having at least a first elastic film made of silicon and a second elastic film formed on the first elastic film and made of a material having higher toughness than the first elastic film, and the diaphragm A piezoelectric element comprising a lower electrode, a piezoelectric layer, and an upper electrode provided on the upper surface; and a protective substrate having a piezoelectric element holding portion that is bonded onto the diaphragm of the flow path forming substrate and protects the piezoelectric element. And a first elastic membrane separating part for separating the first elastic film constituting the diaphragm along the edge of the piezoelectric element holding part at least inside the edge of the piezoelectric element holding part. The liquid ejecting head includes the liquid ejecting head.
In the first aspect of the present invention, it is possible to prevent cracks, cracks, and the like from occurring in the first elastic film constituting the diaphragm due to stress concentration, and to prevent the progress of cracks. Therefore, destruction of the piezoelectric actuator composed of the diaphragm and the piezoelectric element can be reliably prevented.

According to a second aspect of the present invention, in the first aspect, the first elastic membrane separation unit is configured by a first elastic membrane removal unit from which the first elastic membrane is removed. In the liquid jet head.
In the second aspect, the first elastic membrane separation portion can be easily formed, and cracking of the diaphragm can be reliably prevented.

According to a third aspect of the present invention, in the first aspect, the liquid ejection head is characterized in that the first elastic membrane separation unit is configured by a part of the flow path forming substrate.
In the third aspect, the first elastic membrane separation portion can be easily formed, and cracking of the diaphragm can be reliably prevented.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the first elastic membrane separation portion is continuously provided to the outside of the edge portion of the piezoelectric element holding portion. The liquid ejecting head is characterized.
In the fourth aspect, it is possible to more reliably prevent the vibration plate from being cracked.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the first elastic membrane separation portion is continuously provided across a bonding region at a peripheral edge of the piezoelectric element holding portion. The liquid ejecting head is characterized by the above.
In the fifth aspect, it is possible to more reliably prevent the vibration plate from being cracked.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the first elastic membrane separation portion is continuously provided on the edge of the piezoelectric element holding portion over the entire circumference. The liquid ejecting head is characterized by the above.
In the sixth aspect, it is possible to more reliably prevent the vibration plate from being cracked.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the flow path forming substrate has a narrower width than the pressure generation chamber and a common ink chamber of a plurality of pressure generation chambers and each pressure generation An ink supply path that communicates with the chamber, and the protective substrate is bonded to the diaphragm in a region facing the ink supply path, and faces at least the ink supply path at an edge of the piezoelectric element holding portion. The liquid ejecting head is characterized in that the first elastic membrane separation portion is provided in a region to be operated.
In the seventh aspect, even in a region where stress concentration is likely to occur, it is possible to prevent cracking of the diaphragm starting from the first elastic film due to stress concentration.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the flow path forming substrate is made of a silicon single crystal substrate, and the first elastic film thermally oxidizes the flow path forming substrate. The liquid ejecting head is characterized in that it is a thermal oxide film formed by the above.
In the eighth aspect, the first elastic film made of silicon dioxide can be formed easily and satisfactorily.

A ninth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to eighth aspects.
In the ninth aspect, a liquid ejecting apparatus with improved durability and reliability can be realized.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of FIG. The flow path forming substrate 10 according to the present embodiment is made of a silicon single crystal substrate having a plane orientation (110), and one surface thereof is made of silicon dioxide having a thickness of 0.5 to 2 μm formed in advance by thermal oxidation. A first elastic film 50 is formed. A plurality of pressure generating chambers 12 defined by the partition walls 11 are arranged in parallel in the width direction of the flow path forming substrate 10. In addition, 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 supply path 14. The communication unit 13 constitutes a part of the reservoir 100 that communicates with a reservoir unit 32 of the protective 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.

Further, on the opening surface side of the flow path forming substrate 10, a protective film 54 used as a mask when forming the pressure generating chambers 12 is provided on the side opposite to the ink supply path 14 of each pressure generating chamber 12. A nozzle plate 20 having a nozzle opening 21 communicating in the vicinity of the end is fixed through an adhesive, 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 first elastic film 50 made of silicon dioxide and having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. On the first elastic film 50, for example, a second elastic film 55 made of a material having higher toughness than the first elastic film 50 such as zirconium oxide and having a thickness of, for example, about 0.3 μm is formed. . Further, the second elastic film 55 is made of platinum, iridium or the like and has a thickness of, for example, a lower electrode film 60 of about 0.2 μm, lead zirconate titanate (PZT), or the like. The piezoelectric layer 70 made of about 1.0 μm and the upper electrode film 80 made of iridium or the like and having a thickness of, for example, about 0.05 μm are 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 the example described above, the first elastic film 50, the second elastic film 55, and the lower electrode film 60 serve as a diaphragm.

  In addition, a lead electrode 90 made of, for example, gold (Au) or the like is connected to 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. Is applied.

  Further, the piezoelectric element holding portion 31 is provided in a region facing the piezoelectric element 300 on the surface of the flow path forming substrate 10 on the piezoelectric element 300 side, that is, on the second elastic film 55 constituting the diaphragm. The protective substrate 30 is bonded with an adhesive 35. The piezoelectric element holding portion 31 is formed to have a size that integrally covers the plurality of piezoelectric elements 300, and each piezoelectric element 300 is arranged in the piezoelectric element holding portion 31. Thereby, each piezoelectric element 300 is protected in a state hardly affected by the external environment. Note that the piezoelectric element holding portion 31 is not necessarily sealed. Examples of the material of the protective substrate 30 include glass, a ceramic material, a metal, and a resin, and the protective substrate 30 is preferably formed of a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. In the embodiment, the silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  The protective substrate 30 is provided with a reservoir portion 32 that constitutes at least a part of the reservoir 100. As described above, the reservoir portion 32 communicates with the communication portion 13 of the flow path forming substrate 10, and the reservoir 100 is formed by the reservoir portion 32 and the communication portion 13.

  Here, at least a part of the first elastic film 50 is held in the piezoelectric element holding portion 31 at least inside the edge of the piezoelectric element holding portion 31 of the protective substrate 30, that is, in a region facing the piezoelectric element holding portion 31. A first elastic membrane separation part 51 that separates along the edge of the part 31 is provided. For example, in the present embodiment, the first elastic membrane separation part 51 is continuously formed around the periphery of the piezoelectric element holding part. The first elastic membrane separation part 51 makes the first elastic film 50 discontinuous between the inside and the outside of the piezoelectric element holding part 31. In the present embodiment, the first elastic membrane separation unit 51 is constituted by a first elastic membrane removing unit 52 formed by removing the first elastic membrane 50 with a predetermined width. A second elastic film 55 is continuously formed in the elastic film removing portion 52.

  Such a first elastic membrane separation unit 51 may be provided at least in a region facing the piezoelectric element holding unit 31, but from the region facing the piezoelectric element holding unit 31, the piezoelectric element holding unit 31. It is preferable that the outer edge of the protective substrate 30 is continuously formed up to the bonding region where the protective substrate 30 is bonded to the first elastic film 55 (see FIG. 2). In other words, it is preferable that the protective substrate 30 is bonded to the flow path forming substrate 10 so that the edge portion of the piezoelectric element holding portion 31 is located in a region facing the first elastic membrane separation portion 51.

  Thereby, it can prevent that a crack and a crack generate | occur | produce in a diaphragm. Specifically, stress tends to concentrate on the edge portion of the piezoelectric element holding portion 31, and cracks or cracks due to stress concentration occur in this portion of the diaphragm, particularly the first elastic film 50 made of silicon dioxide. Easy to do. However, as in the present embodiment, the first elastic membrane separation portion 51 (first elastic membrane removal portion 52) is provided continuously from the inside to the outside of the edge of the piezoelectric element holding portion 31, and the first elastic membrane separation portion 51 is provided in this portion. If the elastic film 50 of 1 is not present, it is possible to prevent the vibration plate from being cracked due to stress concentration. Therefore, according to such a configuration, it is possible to realize an ink jet recording head in which durability and reliability of a piezoelectric actuator including a diaphragm and a piezoelectric element are improved. In addition, since the yield is improved, the manufacturing cost can be significantly reduced.

  Note that such a first elastic membrane separation unit 51 (first elastic membrane removal unit 52) is formed continuously over the bonding region of the protective substrate 30, for example, as shown in FIG. Also good. Thereby, generation | occurrence | production of the crack of the diaphragm by stress concentration can be prevented further reliably.

  Further, the first elastic membrane separation unit 51 (first elastic membrane removal unit 52) may be provided only at least inside the edge portion of the piezoelectric element holding unit 31, for example, as shown in FIG. That is, it does not have to be provided in the bonding region of the piezoelectric element holding portion 31. In such a configuration, there is a possibility that cracks or the like due to stress concentration may occur in the diaphragm (first elastic film 50) in a region facing the edge of the piezoelectric element holding portion. However, even if a crack or the like occurs, the progress of the crack stops at the first elastic membrane separation portion 51, and therefore does not proceed to the diaphragm in the region facing the piezoelectric element 300. Therefore, destruction of the piezoelectric actuator can be surely prevented.

  In addition, the first elastic membrane separation unit 51 (first elastic membrane removal unit 52) may be provided at least inside the edge of the piezoelectric element holding unit 31 as described above. It is desirable to form near the edge of 31, that is, at a position away from the piezoelectric element 300. This is so that the elastic membrane separation portion 51 does not affect the displacement characteristics of the diaphragm due to the driving of the piezoelectric element 300.

  In the present embodiment, the first elastic membrane separation portion 51 is continuously formed around the periphery of the piezoelectric element holding portion 31. However, the present invention is not limited thereto, and the first elastic membrane separation portion 51 is not limited thereto. May be provided only in a part of the periphery of the piezoelectric element holding portion 31. For example, as in this embodiment, an ink supply path 14 that connects the pressure generating chamber 12 and the communication portion 13 is formed in the flow path forming substrate 10, and the piezoelectric element is held in a region corresponding to the ink supply path 14. When the edge of the part 31 is located, it is desirable to provide the first elastic membrane separation part 51 at least in this part. This is because there is a region where the flow path forming substrate 10 does not exist below the vibration plate in a region corresponding to the ink supply path 14, and cracks due to stress concentration are likely to occur in this portion of the vibration plate.

  In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, 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), and the sealing film 41 seals one surface of the reservoir portion 31. It has been stopped. 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. Thus, it is a flexible part that can be deformed by a change in internal pressure.

  In such an ink jet recording head of this embodiment, ink is taken in from an ink introduction port connected to an external ink supply means (not shown), and the interior from the reservoir 100 to the nozzle opening 21 is filled with ink, and then driving (not shown) is performed. In accordance with a recording signal from the circuit, a voltage is applied between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, and the first elastic film 50, the second elastic film 55, the lower electrode By bending and deforming the film 60 and the piezoelectric layer 70, the pressure in each pressure generating chamber 12 is increased and ink droplets are ejected from the nozzle openings 21.

  Hereinafter, a method for manufacturing such an ink jet recording head will be described with reference to FIGS. 5 to 7 are cross-sectional views of the pressure generation chamber 12 in the longitudinal direction. First, as shown in FIG. 5A, a flow path forming substrate wafer 110 made of a silicon wafer and integrally formed with a plurality of flow path forming substrates 10 is thermally oxidized in a diffusion furnace at about 1100 ° C. Then, a silicon dioxide film 53 constituting the first elastic film 50 is formed. Further, by patterning the silicon dioxide film 53, the first elastic film separating portion 51 is formed at a predetermined position, that is, in a region corresponding to the edge portion of the piezoelectric element holding portion 31 of the protective substrate 30 to be bonded in a process described later. The first elastic film removing portion 52 is formed. 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. 5B, a second elastic film 55 made of zirconium oxide is formed on the first elastic film 50 (silicon dioxide film 53). Specifically, after a zirconium (Zr) layer is formed on the first elastic film 50 (silicon dioxide film 53) by, for example, sputtering, the zirconium layer is formed in a diffusion furnace at 500 to 1200 ° C., for example. A second elastic film 55 made of zirconium oxide (ZrO ₂ ) is formed by thermal oxidation. At this time, the second elastic membrane 55 is continuously formed from above the first elastic membrane 50 to the inside of the first elastic membrane removing section 52, whereby the first elastic membrane separating section 51 is formed. The

  Next, as shown in FIG. 5C, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the second elastic film 55, the lower electrode film 60 is patterned into a predetermined shape. To do. Next, as shown in FIG. 5 (d), a piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) and an upper electrode film 80 made of, for example, iridium are connected to a wafer 110 for flow path forming substrate. The piezoelectric element 300 is formed by patterning the piezoelectric layer 70 and the upper electrode film 80 in regions facing the pressure generation chambers 12.

The material of the piezoelectric layer 70 constituting the piezoelectric element 300 is, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT), or niobium, nickel, magnesium, bismuth, yttrium, or the like. A relaxor ferroelectric or the like to which a metal 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 2/3 ) O ₃ —PbTiO ₃ (PST-PT), Pb (Sc _1/3 Nb _2/3 ) 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. 6A, lead electrodes 90 are formed. Specifically, first, a metal layer 95 made of, for example, gold (Au) or the like is formed over the entire surface of the flow path forming substrate wafer 110. Then, a mask pattern (not shown) made of, for example, a resist is formed on the metal layer 95, and the lead electrode 90 is formed by patterning the metal layer 95 for each piezoelectric element 300 through the mask pattern. .

  Next, as shown in FIG. 6B, a protective substrate wafer 130 in which a plurality of protective substrates 30 holding a plurality of patterned piezoelectric elements are integrally formed is formed on a flow path forming substrate wafer 110. For example, the bonding is performed by the adhesive 35. Note that a reservoir portion 32, a piezoelectric element holding portion 31, and the like are formed in advance on the protective substrate wafer 130. Further, the protective substrate wafer 130 is a silicon wafer having a thickness of about 400 μm, for example, and the rigidity of the flow path forming substrate wafer 110 is significantly improved by bonding the protective substrate wafer 130.

  Next, as shown in FIG. 6C, the surface opposite to the protective substrate wafer 130 side of the flow path forming substrate wafer 110 is processed so that the flow path forming substrate wafer 110 has a predetermined thickness. . Specifically, the flow path forming substrate wafer 110 is first ground to a certain thickness. Thereafter, the flow path forming substrate wafer 110 is formed to a predetermined thickness by wet etching using an etchant such as hydrofluoric acid.

  Next, as shown in FIG. 7A, a protective film 54 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. 7B, the flow path forming substrate wafer 110 is anisotropically etched (wet etching) using the protective film 54 as a mask, so that a pressure generating chamber is formed in the flow path forming substrate wafer 110. 12, a communication portion 13, an ink supply path 14, and the like are formed. Next, as shown in FIG. 7C, the first elastic film 50 and the second elastic film between the communication portion 13 of the flow path forming substrate wafer 110 and the reservoir portion 32 of the protective substrate wafer 130. 55 is removed, and the communication unit 13 and the reservoir unit 32 are connected to form the reservoir 100.

  Thereafter, although not shown, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer 130 are removed by cutting, for example, by dicing. The nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 130. The ink jet recording head having the above-described structure is manufactured by separating the flow path forming substrate wafer 110 and the like into a single chip size flow path forming substrate 10 as shown in FIG.

(Embodiment 2)
FIG. 8 is a cross-sectional view of the ink jet recording head according to the second embodiment. The present embodiment is another example of the first elastic membrane separation unit 51. As shown in FIG. 8, the first elastic membrane separation unit 51 is configured by a silicon single crystal substrate that is the flow path forming substrate 10. Except that, it is the same as the first embodiment. Of course, even with such a configuration, the same effect as in the first embodiment can be obtained.

  A method for forming the first elastic membrane separation unit 51 according to the present embodiment is not particularly limited. For example, as in the first embodiment, the flow path forming substrate 10 (flow path forming substrate wafer 110). ) Is thermally oxidized to form the first elastic film 50 (silicon dioxide film 53), the flow path forming substrate 10 is protected in a state in which a portion serving as the first elastic film separating portion 51 is protected by a predetermined mask. The first elastic membrane 50 made of a thermal oxide film may be formed in a region other than the portion that becomes the first elastic membrane separation portion 51 by thermal oxidation.

(Other embodiments)
While the embodiments of the present invention have been described above, the basic configuration of the ink jet recording head is not limited to that described above. For example, in the above-described embodiment, the first elastic film 50 made of the thermal oxide film is exemplified by thermally oxidizing the flow path forming substrate (flow path forming substrate wafer). However, the first elastic film 50 is formed. The method is not particularly limited. Of course, the first elastic film 50 may be formed by a CVD method or the like. Further, for example, in the first embodiment, the structure in which the second elastic film 55 formed on the first elastic film 50 is continuously formed in the first elastic film removing unit 52 is exemplified. However, the present invention is not limited thereto, and the first elastic membrane separation unit 51 may be formed by separately providing a layer made of, for example, silicon nitride in the first elastic membrane removal unit 52.

  Such an ink jet recording head constitutes a part of a recording head unit including an ink flow path communicating with an ink cartridge or the like, and is mounted on the ink jet recording apparatus. FIG. 9 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 9, in the recording head units 1A and 1B having the ink jet recording head, cartridges 2A and 2B constituting ink supply means are detachably provided, and a carriage 3 on which the recording head units 1A and 1B are mounted. Is provided on a carriage shaft 5 attached to the apparatus body 4 so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  In the above-described embodiment, an ink jet recording head has been described as an example of a liquid ejecting head. However, the present invention is intended for a wide range of liquid ejecting heads, and is a liquid that ejects liquids other than ink. Of course, the present invention can also be applied to an ejection 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. FIG. 6 is a cross-sectional view illustrating a modification of the recording head according to the first embodiment. FIG. 6 is a cross-sectional view illustrating a modification of the recording head according to the first embodiment. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 6 is a cross-sectional view of a recording head according to Embodiment 2. FIG. 1 is a schematic diagram of a recording apparatus according to an embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Piezoelectric element holding part, 32 Reservoir part, 40 Compliance board, 50 1st Elastic membrane, 51 first elastic membrane separation unit, 52 first elastic membrane removal unit, 55 second elastic membrane, 60 lower electrode film, 70 piezoelectric layer, 80 upper electrode film, 90 lead electrode, 100 reservoir, 300 Piezoelectric element

Claims (9)

A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for injecting liquid is formed, a first elastic film made of silicon dioxide provided on one side of the flow path forming substrate, and the first elasticity A diaphragm having at least a second elastic film made of a material having higher toughness than the first elastic film provided on the film, and a lower electrode, a piezoelectric layer, and an upper electrode provided on the diaphragm And a protective substrate having a piezoelectric element holding portion which is bonded onto the diaphragm of the flow path forming substrate and protects the piezoelectric element, and at least inside the edge of the piezoelectric element holding portion The liquid ejecting head further includes a first elastic film separating portion that separates the first elastic film constituting the diaphragm along the edge of the piezoelectric element holding portion. The liquid ejecting head according to claim 1, wherein the first elastic membrane separation unit includes a first elastic membrane removing unit from which the first elastic membrane is removed. The liquid ejecting head according to claim 1, wherein the first elastic membrane separation unit is configured by a part of the flow path forming substrate. 4. The liquid ejecting head according to claim 1, wherein the first elastic membrane separation portion is continuously provided to an outside of an edge portion of the piezoelectric element holding portion. 5. The liquid ejecting head according to claim 1, wherein the first elastic membrane separation unit is continuously provided over a bonding region at a peripheral edge of the piezoelectric element holding unit. The liquid ejecting head according to claim 1, wherein the first elastic membrane separating portion is continuously provided over an entire circumference at an edge of the piezoelectric element holding portion. . 7. The ink supply path according to claim 1, wherein the flow path forming substrate has a narrower width than the pressure generation chamber and communicates the common ink chamber of the plurality of pressure generation chambers with each pressure generation chamber. In addition, the protective substrate is bonded to the diaphragm in a region facing the ink supply path, and the first elastic film is formed in at least a region of the edge of the piezoelectric element holding portion facing the ink supply path. A liquid ejecting head including a separation unit. 8. The flow path forming substrate according to claim 1, wherein the flow path forming substrate is a silicon single crystal substrate, and the first elastic film is a thermal oxide film formed by thermally oxidizing the flow path forming substrate. A liquid ejecting head characterized by the above. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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