JP2006255972A - Liquid jetting head, and liquid jetting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting head and a liquid jetting device which can prevent the decrease of liquid discharging characteristics resulting from a voltage drop from occurring, and also, can prevent the peeling or the cracking of a vibration plate or the like from occurring. <P>SOLUTION: This liquid jetting head is equipped with a conduit forming board 10, a common electrode 60, a plurality of piezoelectric elements, an insulating film 100, and dispensing wiring 97 for a common electrode. In this case, for the conduit forming board 10, a plurality of pressure generating chambers 12 which communicate with a nozzle opening for jetting a liquid are formed. The common electrode 60 is provided on one surface side of the conduit forming board 10 through the vibration plate. A plurality of the piezoelectric elements comprise an piezoelectric body layer and an individual electrode, and are provided in parallel in the width direction. The insulating film 100 is provided to cover at least the piezoelectric elements. The dispersing wiring 97 for the common electrode is extended on the insulating film 100, and at the same time, is connected with the common electrode 60 through a contact hole 102 which is formed on the insulating film 100. Also, a plurality of the contact holes 102 are formed with a specified interval in the longitudinal direction of the piezoelectric elements on the insulating film 100 in a region facing a bulkhead 11 which partitions the pressure generating chamber. The dispersing wiring 97 for the common electrode is connected with the common electrode 60 through each of a plurality of the contact holes 102. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject liquid, and more particularly, to an ink jet recording head and an ink jet recording apparatus that eject ink droplets.

  A part of the pressure generating chamber communicating with the nozzle opening is constituted by a diaphragm, and the diaphragm is deformed by a piezoelectric element to pressurize ink in the pressure generating chamber and eject ink droplets from the nozzle opening. There are two types in practical use, one using a piezoelectric actuator in a longitudinal vibration mode that extends and contracts in the axial direction of the piezoelectric element and one using a piezoelectric actuator in a flexural vibration mode.

  For example, the latter actuator using the flexural vibration mode is formed by forming a uniform piezoelectric material layer over the entire surface of the diaphragm by a film forming technique, and generating pressure by lithography using this piezoelectric material layer. A device in which a piezoelectric element is formed so as to be separated into shapes corresponding to chambers and independent for each pressure generating chamber is known. Such piezoelectric elements can be arranged at a relatively high density.

  Here, since such a piezoelectric element has one electrode shared by a plurality of piezoelectric elements, when a large number of piezoelectric elements arranged at high density are driven simultaneously, a voltage drop occurs and the piezoelectric element There is a problem that the amount of displacement becomes unstable and the ink ejection characteristics vary. In order to solve such a problem, for example, the bypass electrode is drawn out from the lower electrode film which is a common electrode, and the resistance value of the lower electrode film is substantially reduced by the bypass electrode, so that the ink ejection characteristics as described above are obtained. (For example, see Patent Document 1).

  However, when the bypass wiring is formed in this way, for example, by sputtering or vapor deposition, the lower electrode film or the lower diaphragm is peeled off or cracked due to stress generated in the manufacturing process. There is. Specifically, in order to form a bypass wiring having good adhesion to the substrate by sputtering or the like, it is necessary to heat the flow path forming substrate on which the bypass wiring is formed to a predetermined temperature during the film formation. . Since the linear expansion coefficient is different between the bypass wiring and the diaphragm or the like provided below the bypass wiring, when the bypass wiring is formed in such a state that the substrate is heated in this way, the lower wiring of the bypass wiring is cooled during the subsequent cooling. There is a problem in that residual film stress acts on a diaphragm or the like due to a difference in shrinkage, resulting in peeling or cracking.

JP 2004-154987 A (claims, etc.)

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus that can prevent a decrease in liquid ejection characteristics due to a voltage drop and can prevent peeling and cracking of a diaphragm and the like. .

According to a first aspect of the present invention for solving the above-mentioned problems, a flow path forming substrate in which a plurality of pressure generating chambers communicating with a nozzle opening for ejecting a liquid are formed, and a diaphragm on one surface side of the flow path forming substrate are provided. A plurality of piezoelectric elements that are arranged in parallel along the width direction, and an insulating film that covers at least the piezoelectric element, and extends on the insulating film. And a common electrode lead-out wiring connected to the common electrode through a contact hole formed in the insulating layer film, and the contact hole faces a partition wall defining the pressure generating chamber A plurality of the insulating film in the region are formed at predetermined intervals along the longitudinal direction of the piezoelectric element, and the common electrode lead-out wiring is in contact with the common electrode through each of the plurality of contact holes. A liquid-jet head, characterized in that it is.
In the first aspect, since the common electrode lead-out wiring is provided, the resistance value of the common electrode constituting the piezoelectric element is substantially reduced. Therefore, the voltage drops even when a large number of piezoelectric elements are driven simultaneously. Can be prevented. In addition, when the common electrode lead-out wiring is formed, stress generated in the common electrode, the diaphragm, and the like can be suppressed. Therefore, it is possible to prevent the common electrode, the diaphragm and the like from being peeled off or cracked due to this stress.

According to a second aspect of the invention, in the liquid jet head according to the first aspect, the opening length of the contact hole is wider than an interval between the adjacent contact holes.
In the second aspect, when the common electrode lead-out wiring is formed, the stress generated in the common electrode, the diaphragm, and the like is more reliably suppressed.

A third aspect of the present invention is the liquid ejecting head according to the first or second aspect, wherein an opening length of the contact hole is wider than an opening width of the contact hole.
In the third aspect, when the common electrode lead-out wiring is formed, the stress generated in the common electrode, the diaphragm and the like can be more reliably suppressed.

According to a fourth aspect of the present invention, in the liquid jet head according to any one of the first to third aspects, the common electrode lead-out wiring includes a metal layer made of at least aluminum.
In the fourth aspect, the resistance value of the common electrode can be more reliably lowered to prevent a voltage drop.

According to a fifth aspect of the present invention, in the fourth aspect, the common electrode lead-out wiring is composed of the metal layer and an adhesive layer made of an adhesive metal provided below the metal layer. The liquid ejecting head is characterized by the above.
In the fifth aspect, the common electrode lead-out wiring can be satisfactorily formed, and the resistance value of the common electrode can be more reliably reduced to prevent a voltage drop.

According to a sixth aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to fifth aspects.
In the sixth aspect, it is possible to realize a liquid ejecting apparatus that greatly improves the ejection characteristics and reliability of the head.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view of the ink jet recording head according to the first embodiment. FIG. 2 is a plan view of the ink jet recording head according to the first embodiment and its AA ′ sectional view. As shown in the figure, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in the present embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation, and has a thickness of 0.5. An elastic film 50 of ˜2 μm is provided. The flow path forming substrate 10 is provided with a plurality of pressure generating chambers 12 formed by performing anisotropic etching from the other side and partitioned by partition walls 11.

  Further, on the outside of the direction (longitudinal direction) perpendicular to the direction in which the pressure generating chambers 12 are arranged (width direction), there is a communication that forms part of a reservoir that serves as a common ink chamber for each pressure generating chamber 12. A portion 13 is formed, and the communication portion 13 is in communication with one end portion in the longitudinal direction of each pressure generating chamber 12 via an ink supply path 14. The cross-sectional area of each ink supply path 14 communicating with one end of each pressure generation chamber 12 is smaller than that of the pressure generation chamber 12, and the flow path resistance of the ink flowing into the pressure generation chamber 12 is constant. keeping.

Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 in which a nozzle opening 21 communicating with the vicinity of the end portion of each pressure generating chamber 12 opposite to the ink supply path 14 is formed is a mask film. It is fixed via an adhesive or a heat-welded film via 51. 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. Further, the nozzle plate 20 may be formed of a material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10.

  On the other hand, the elastic film 50 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 as described above. For example, an insulator film 55 of about 0.4 μm is formed. Further, on the insulator film 55, 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 A piezoelectric element 300 composed of an upper electrode film 80 of .05 μm is formed. In general, one of the electrodes of the piezoelectric element 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 the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for convenience of a 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. Further, each upper electrode film 80 that is an individual electrode of the piezoelectric element 300 extends from the vicinity of the end of the pressure generating chamber 12 opposite to the ink supply path 14 to the vicinity of the end of the flow path forming substrate 10. An upper electrode lead wiring 90 is connected.

  Here, the piezoelectric element 300 will be described in detail. The lower electrode film 60, which is a common electrode of the piezoelectric element 300, is formed in a region facing the pressure generation chamber 12 in the longitudinal direction of the pressure generation chamber 12, and a plurality of pressure generation chambers 12 in the direction in which the pressure generation chambers 12 are arranged side by side. It is provided continuously over the area corresponding to. The lower electrode film 60 is extended to the vicinity of the end of the flow path forming substrate 10 in the direction in which the pressure generating chambers 12 are arranged, and in the present embodiment, a plurality of upper electrode lead wires that are drawn from each piezoelectric element 300. It is continuously provided so as to surround the periphery of 90.

  The piezoelectric layer 70 and the upper electrode film 80 are basically provided in a region facing the pressure generation chamber 12, but in the longitudinal direction of the pressure generation chamber 12, the piezoelectric layer 70 and the upper electrode film 80 are outside the end portion of the lower electrode film 60. The end surface of the lower electrode film 60 is covered with the piezoelectric layer 70.

  In addition, a first insulating film 100 made of an inorganic insulating material is formed in the pattern region of each layer constituting such a piezoelectric element 300, and each layer constituting the piezoelectric element 300 is covered with this first insulating film 100. It has been broken. The upper electrode lead-out wiring 90 includes a first lead electrode 91 connected to the upper electrode film 80 and a second lead electrode 94 connected to the first lead electrode 91 in the present embodiment. . The first lead electrode 91 extends on the first insulating film 100 and is connected to the upper electrode film 80 through a contact hole 101 formed in the first insulating film 100. Each layer constituting the first lead electrode 91 and the piezoelectric element 300 is further covered with a second insulating film 110 made of an inorganic insulating material. The second lead electrode 94 constituting the upper electrode lead-out wiring 90 extends on the second insulating film 110, and the first lead is passed through the contact hole 111 formed in the second insulating film 110. It is connected to the electrode 91. A connection wiring 135 drawn from a driving IC 130 mounted on a protective substrate 30 described later is connected to the vicinity of the tip of the second lead electrode 94.

  Here, in the present embodiment, the first lead electrode 91 includes an adhesion layer 92 having a thickness of about 0.1 to 0.5 μm and a metal layer 93 having a thickness of about 0.5 to 3 μm. ing. Examples of the material of the adhesion layer 92 include nickel (Ni), chromium (Cr), titanium (Ti), copper (Cu), titanium tungsten (TiW), and the like. Examples of the material of the metal layer 93 include gold (Au) and aluminum (Al). In the present embodiment, the adhesion layer 92 constituting the first lead electrode 91 is made of titanium tungsten (TiW), and the metal layer 93 is made of aluminum (Al).

  Similar to the first lead electrode 91, the second lead electrode 94 includes an adhesion layer 95 and a metal layer 96. For example, in the present embodiment, the adhesion layer 95 constituting the second lead electrode 94 is made of nickel chrome (NiCr), and the metal layer 96 is made of gold (Au).

The material of the first and second insulating films 100 and 110 is not particularly limited as long as it is an inorganic insulating material, and examples thereof include aluminum oxide (AlO _x ) and tantalum oxide (TaO _x ). In particular, it is preferable to use an inorganic amorphous material such as aluminum oxide (Al ₂ O ₃ ).

In the present embodiment, the first electrode made of the same layer as the first lead electrode 91 (the adhesion layer 92 and the metal layer 93) is formed on the lower electrode film 60 in the region outside the pressure generation chamber 12 arranged side by side. The laminated electrode 140 is provided via the first insulating film 100 described above and is electrically connected to the lower electrode film 60. The first laminated electrode 140 only needs to be electrically connected to the lower electrode film 60 constituting the piezoelectric element 300, that is, the lower electrode film 60 in the region corresponding to the pressure generating chamber 12. The lower electrode film 60 may not be provided below the stacked electrode 140.
Further, in the region between the piezoelectric elements 300 arranged side by side, for example, a lower electrode lead-out wiring 97 (continuous from the first laminated electrode 140 at a ratio of about one for ten piezoelectric elements) ( Common electrode lead-out wiring) is provided.

  In the present embodiment, the lower electrode lead-out wiring 97 is composed of an adhesion layer 92 and a metal layer 93 that constitute the first lead electrode 91 as shown in FIG. 3, and is provided outside the piezoelectric element 300 in the longitudinal direction. The first laminated electrode 140 is continuously formed from the region facing the partition wall 11. The lower electrode lead-out wiring 97 is extended on the first insulating film 100, and a region corresponding to the pressure generating chamber 12 through a contact hole 102 provided in the first insulating film 100. The lower electrode film 60 is electrically connected. Note that the lower electrode lead-out wiring 97 is preferably formed as narrow as possible so as not to hinder the displacement of the diaphragm due to the driving of the piezoelectric element 300. For example, in this embodiment, the contact hole is formed as a contact hole. The width is smaller than 102.

  Here, the first insulating film 100 in the region facing the partition wall 11 is provided with a plurality of contact holes 102 at predetermined intervals along the longitudinal direction of the piezoelectric element 300. Each of the plurality of contact holes 102 is connected to the lower electrode film 60. In this way, the lower electrode lead-out wiring 97 and the lower electrode film 60 are connected via the plurality of contact holes 102, thereby forming the lower electrode lead-out wiring 97 (first laminated electrode 140). At this time, the stress generated in the lower electrode film 60, the insulator film 55, the elastic film 50, and the like in the region corresponding to the contact hole 102 can be suppressed to be relatively small. Therefore, it is possible to prevent the lower electrode film 60, the insulator film 55, or the elastic film 50 in the region corresponding to the contact hole 102 from being peeled off during the manufacturing process. In particular, the insulating film 55 and the elastic film 50 have weak adhesion between the layers, and peeling between them is likely to occur. However, according to the present invention, the peeling of the insulating film 55 and the elastic film 50 can be prevented. Can do. Even if peeling occurs, since there are a plurality of contact holes 102 and the size of each contact hole is small, the peeling region does not extend to a region corresponding to the piezoelectric element 300 and affects the driving of the piezoelectric element 300. Can be kept extremely small. A method of manufacturing the lower electrode lead-out wiring 97 will be described later in detail.

  In addition, a plurality of such contact holes 102 may be provided in a region facing the partition wall 11, but each contact hole 102 is a contact hole adjacent to the opening length a as shown in FIG. It is preferable that the relationship with the distance b to 102 satisfies a <b. Further, each contact hole 102 is preferably formed so that the relationship between the opening length a and the opening width c satisfies c <a. Thereby, it is possible to more reliably prevent the lower electrode film 60, the insulator film 55, the elastic film 50, and the like described above from being peeled by stress.

  In addition, on the surface of the flow path forming substrate 10 on the piezoelectric element 300 side, a protective substrate 30 having a piezoelectric element holding portion 31 capable of ensuring a space that does not hinder the movement of the region facing the piezoelectric element 300 is provided, for example. And are bonded via an adhesive 35. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. The piezoelectric element holding portion 31 may be sealed, but of course may not be sealed.

  The protective substrate 30 is provided with a reservoir portion 32 in a region corresponding to the communication portion 13 of the flow path forming substrate 10. In this embodiment, the reservoir portion 32 is provided along the direction in which the pressure generating chambers 12 are arranged so as to penetrate the protective substrate 30 in the thickness direction, and as described above, the communication portion of the flow path forming substrate 10. The reservoir 120 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12. Furthermore, an exposed hole 33 through which the second lead electrode 94 is exposed through the protective substrate 30 in the thickness direction is formed in a region opposite to the reservoir portion 32 of the piezoelectric element holding portion. Then, the connection wiring 135 drawn from the driving IC 130 mounted on the protective substrate 30 is connected to the second lead electrode 94 and the first laminated electrode 140 (lower electrode film 60) in the exposed hole 33. ing.

  Examples of the material of the protective substrate 30 include glass, ceramic material, metal, resin, and the like, but it is more preferable that the protective substrate 30 be formed of substantially the same material as the thermal expansion coefficient of the flow path forming substrate 10. In the embodiment, a single crystal silicon substrate made of the same material as the flow path forming substrate 10 is used.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective 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 area of the fixing plate 42 facing the reservoir 120 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 120 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 120 to the nozzle opening 21, and then mounted on the protective substrate 30. In accordance with a recording signal from the IC 130, 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 elastic film 50, the insulator film 55, the lower electrode film 60, and the piezoelectric body. By bending and deforming the layer 70, the pressure in each pressure generation 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. FIG. 6 is a cross-sectional view in the width direction of the pressure generating chamber, and the other drawings are cross-sectional views in the longitudinal direction of the pressure generating chamber.

First, as shown in FIG. 4A, a channel forming substrate wafer 160, which is a silicon wafer, is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film 52 constituting the elastic film 50 is formed on the surface. To do. In the present embodiment, a silicon wafer having a relatively large thickness and high rigidity of about 625 μm is used as the flow path forming substrate wafer 160 (flow path forming substrate 10). Next, as shown in FIG. 4B, a zirconium (Zr) layer is formed on the elastic film 50 (silicon dioxide film 52), and then thermally oxidized in a diffusion furnace at 500 to 1200 ° C., for example, to form zirconium oxide ( An insulator film 55 made of ZrO ₂ ) is formed. Next, as shown in FIG. 4C, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 55, the lower electrode film 60 is patterned into a predetermined shape.

  Next, as shown in FIG. 4D, for example, a piezoelectric layer 70 made of lead zirconate titanate (PZT) or the like and an upper electrode film 80 made of iridium (Ir) or the like are formed as flow paths. After forming the entire surface of the substrate wafer 160, 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.

As a material of the piezoelectric layer 70, for example, a relaxor ferroelectric material obtained by adding a metal such as niobium, nickel, magnesium, bismuth or yttrium to a ferroelectric piezoelectric material such as lead zirconate titanate (PZT). Etc. may be used. The composition may be appropriately selected in consideration of the characteristics and application of the piezoelectric element. 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 Etc. The. The method for manufacturing the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or the like may be used.

  Next, a first insulating film 100 made of aluminum oxide is formed. Specifically, as shown in FIGS. 5A and 6A, first, after the first insulating film 100 is formed on the entire surface of the flow path forming substrate wafer 160, for example, a mask made of resist or the like. The first insulating film 100 is etched through (not shown) to form contact holes 101 and 102.

  In the present embodiment, the first insulating film 100 other than the pattern region of each layer constituting the piezoelectric element 300 is removed. Of course, the first insulating film 100 may be provided other than the pattern region. The patterning method of the first insulating film 100 is not particularly limited, but it is preferable to use dry etching such as ion milling, for example. Thereby, the first insulating film 100 can be selectively removed favorably.

  Next, the first lead electrode 91 is formed, and the first laminated electrode 140 and the lower electrode lead wiring 97 are formed. Specifically, first, as shown in FIGS. 5B and 6B, an adhesion layer 92 made of, for example, titanium tungsten (TiW) is formed over the entire surface of the flow path forming substrate wafer 160. Then, a metal layer 93 made of, for example, aluminum (Al) is formed on the entire surface of the adhesion layer 92. Thereafter, as shown in FIGS. 5C and 6C, for example, the metal layer 93 and the adhesion layer 92 are sequentially etched (wet etching) through a mask (not shown) made of a resist or the like. The first lead electrode 91, the first laminated electrode 140, and the lower electrode lead-out wiring 97 are formed.

  Here, the adhesion layer 92 and the metal layer 93 constituting the lower electrode lead-out wiring 97 are formed while the flow path forming substrate wafer 160 is heated, and then cooled. Since the linear expansion coefficients of the materials constituting the layers such as the lower electrode lead-out wiring 97, the lower electrode film 60, the insulator film 55, and the elastic film 50 are different, the shrinkage rates of the layers during the cooling are also different. Due to the difference in shrinkage rate, stress is generated in each of the layers, and there is a possibility that the lower electrode film 60, the insulator film 55, the elastic film 50, and the like are peeled off due to the stress. In particular, in a region corresponding to the contact hole 102 in which the lower electrode lead-out wiring 97 is in contact with the lower electrode film 60, peeling due to such stress is likely to occur.

  However, in the present invention, the lower electrode lead-out wiring 97 is connected through the plurality of contact holes 102 provided in the first insulating film 100, and the lower electrode film 60 and the lower electrode lead-out are connected to each contact hole 102. The contact area with the wiring 97 is kept relatively small. For this reason, when the adhesion layer 92 and the metal layer 93 are formed, the stress generated in the portion corresponding to the contact hole 102 is suppressed to be extremely small, and peeling of the lower electrode film 60, the insulator film 55, the elastic film 50, and the like is prevented. can do.

  After forming the lower electrode lead-out wiring 97 and the like in this way, as shown in FIG. 7A, the second insulating film 110 is formed on the entire surface of the flow path forming substrate wafer 160. Etching through a mask (not shown) made of resist or the like forms contact holes 111 and the like. In the present embodiment, like the first insulating film 100, the second insulating film 110 other than the pattern region of each layer constituting the piezoelectric element 300 is removed.

  Next, as shown in FIG. 7B, an adhesion layer 95 made of, for example, nickel chrome (NiCr) is formed over the entire surface of the flow path forming substrate wafer 160, and the entire surface on the adhesion layer 95 is formed. For example, a metal layer 96 made of gold (Au) or the like is formed. Thereafter, the metal layer 96 and the adhesion layer 95 are sequentially etched through a mask pattern (not shown) to form the second lead electrode 94.

  Next, as shown in FIG. 7C, a protective substrate wafer 170 that is a silicon wafer and serves as a plurality of protective substrates is bonded to the flow path forming substrate wafer 160 on the piezoelectric element 300 side. Next, as shown in FIG. 8 (a), the flow path forming substrate wafer 160 is polished to a certain thickness, and then wet etched with hydrofluoric acid to make the flow path forming substrate wafer 160 a predetermined thickness. To. For example, in this embodiment, the flow path forming substrate wafer 160 is processed so as to have a thickness of about 70 μm. Next, as shown in FIG. 8B, a mask film 51 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 160 and patterned into a predetermined shape. Then, the flow path forming substrate wafer 160 is anisotropically etched through the mask film 51 to form the pressure generating chamber 12, the communication portion 13, the ink supply path 14, and the like in the flow path forming substrate wafer 160. (FIG. 8 (c)).

  After that, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 160 and the protective substrate wafer 170 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 160 opposite to the protective substrate wafer 170 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 170. The ink jet recording head of this embodiment is obtained by dividing the flow path forming substrate wafer 160 and the like into the flow path forming substrate 10 and the like having one chip size as shown in FIG.

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the lower electrode lead-out wiring 97 made of the same layer as the first stacked electrode 140 (first lead electrode 91) is illustrated, but the present invention is not limited to this. The lower electrode lead wiring made of the same layer as the lead electrode may be connected to the lower electrode film via a plurality of contact holes formed in the first and second insulating films. Even in such a configuration, by connecting to the lower electrode film through a plurality of contact holes, the same effects as those of the above-described embodiment can be obtained.

  The ink jet recording head according to the above-described embodiment 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, the ink jet recording head has been described as an example of the liquid ejecting head of the present invention. However, the basic configuration of the liquid ejecting head is not limited to the above-described configuration. The present invention covers a wide range of liquid ejecting heads, and can naturally be applied to those ejecting liquids other than ink. 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. It is the top view and sectional drawing which show the structure of the extraction wiring for lower electrodes. 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. 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. 1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board | substrate, 40 Compliance board | substrate, 60 Lower electrode film, 70 Piezoelectric layer, 80 Upper electrode film, 90 Lead-out wiring for upper electrode, 91 First lead electrode, 92, 95 Adhesion layer, 93, 96 Metal layer, 94 Second lead electrode, 97 Lower electrode lead-out wiring, 100 First insulating film, 110 Second insulating film, 120 Reservoir, 140 First laminated electrode, 300 piezoelectric element

Claims (6)

  A flow path forming substrate in which a plurality of pressure generating chambers communicating with nozzle openings for injecting liquid are formed, and a common electrode, a piezoelectric layer, and individual electrodes provided on one surface side of the flow path forming substrate via a vibration plate And a plurality of piezoelectric elements arranged in parallel along the width direction, an insulating film provided to cover at least the piezoelectric element, and a contact hole extending on the insulating film and formed in the insulating film. A common electrode lead-out line connected to the common electrode, and the contact hole extends along the longitudinal direction of the piezoelectric element in the insulating film in a region facing the partition wall defining the pressure generating chamber. A liquid ejecting head, wherein a plurality of common electrode lead-out lines are connected to the common electrode through each of the plurality of contact holes.   The liquid ejecting head according to claim 1, wherein an opening length of the contact hole is wider than an interval between the adjacent contact holes.   3. The liquid ejecting head according to claim 1, wherein an opening length of the contact hole is wider than an opening width of the contact hole.   The liquid ejecting head according to claim 1, wherein the common electrode lead-out wiring includes a metal layer made of at least aluminum.   5. The liquid jet head according to claim 4, wherein the common electrode lead-out wiring includes the metal layer and an adhesive layer made of an adhesive metal provided below the metal layer. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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