JP4506145B2 - Liquid ejecting head, manufacturing method thereof, and liquid ejecting apparatus - Google Patents

Description

  The present invention relates to a liquid ejecting head that ejects a liquid to be ejected, a method for manufacturing the same, and a liquid ejecting apparatus, and in particular, pressurizes ink supplied to a pressure generating chamber that communicates with a nozzle opening that ejects ink droplets using a piezoelectric element. The present invention relates to an ink jet recording head that discharges ink droplets from a nozzle opening, a manufacturing method thereof, and an ink jet recording apparatus.

  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 an ink jet recording head requires a drive IC (semiconductor integrated circuit) for driving the piezoelectric element. This drive IC is mounted on a substrate that is bonded to a flow path forming substrate in which a pressure generating chamber is formed, for example, a reservoir forming substrate, and adopts a structure that is connected to each piezoelectric element by wire bonding (Patent Document). 1).

  However, in an ink jet recording head having such a structure, a drive wiring for connecting to an external wiring or the like is generally provided on a reservoir forming substrate, and a drive IC is fixed on the drive wiring by an adhesive. Therefore, there is a problem that the drive wiring and the drive IC are short-circuited to destroy the drive IC and the like. For example, when the drive IC is fixed on the wiring pattern in this way, an insulating material is used as the adhesive, but it is still impossible to completely prevent the short circuit between the two. 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.

Japanese Patent Laid-Open No. 2002-160366 (page 6, FIG. 1-2)

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head, a manufacturing method thereof, and a liquid ejecting apparatus that can reliably prevent a short circuit between a drive IC and a drive wiring.

According to a first aspect of the present invention for solving the above problem, a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, and a diaphragm is provided on one surface side of the flow path forming substrate. And a protective substrate having a piezoelectric element holding portion that is bonded to a surface of the flow path forming substrate on the piezoelectric element side and protects the piezoelectric element; In a liquid ejecting head including a driving IC provided on the protective substrate and driving the piezoelectric element, the driving IC is fixed on a driving wiring formed on the surface of the protective substrate with an adhesive. In addition, a liquid characterized in that the drive IC and the drive wiring are connected by a connection wiring made of a bonding wire, and a granular insulator having a certain size is mixed in the adhesive. In the injection head.
In the first aspect, since the contact between the drive IC and the drive wiring is prevented by the granular insulator, it is possible to reliably prevent the short circuit between them.

According to a second aspect of the present invention, in the first aspect, the liquid ejecting head is characterized in that a particle diameter of the insulator is larger than a thickness of the drive wiring.
In the second aspect, the contact between the drive IC and the drive wiring can be reliably prevented.

According to a third aspect of the present invention, in the liquid jet head according to the first or second aspect, the insulator is spherical.
In the third aspect, since the particle size of the insulator is constant regardless of the direction of each particle, the drive IC is not adhered in a tilted state.

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 insulator is silicon oxide, silicon nitride, or tantalum oxide.
In the fourth aspect, by using a predetermined material as the insulator, it is possible to prevent the drive IC and the drive wiring from being short-circuited and to satisfactorily join them.

According to a fifth aspect of the present invention, in the liquid jet head according to any one of the first to third aspects, the insulator is made of a resin material.
In the fifth aspect, by using a predetermined material as the insulator, it is possible to prevent a short circuit between the drive IC and the drive wiring and to satisfactorily join them.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the insulator is mixed in the adhesive at a ratio of 0.1 wt% to 30 wt%. Located in the liquid jet head.
In the sixth aspect, since the insulator is mixed with the adhesive at a predetermined ratio, the drive IC is not inclined and bonded, and no defect due to the stress of the insulator occurs.

A seventh aspect of the present invention is a liquid ejecting apparatus including any one of the first to sixth liquid ejecting heads.
In the seventh aspect, a liquid ejecting apparatus with improved durability and reliability can be realized.

According to an eighth aspect of the present invention, there is provided a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting a liquid is formed, and provided on one surface side of the flow path forming substrate via a diaphragm. A piezoelectric element that causes a pressure change in the pressure generating chamber; a protective substrate having a piezoelectric element holding portion that is bonded to the surface of the flow path forming substrate on the piezoelectric element side and protects the piezoelectric element; and on the protective substrate A liquid ejecting head manufacturing method comprising a driving IC for driving the piezoelectric element that is fixed, and a granular insulator having a certain size on the surface of the protective substrate on which driving wiring is formed A method of manufacturing a liquid ejecting head, comprising: applying a mixed adhesive by transfer; and placing the driving IC on the adhesive to cure the adhesive. .
In the eighth aspect, since the adhesive mixed with the insulator is applied at a predetermined thickness, the drive IC is satisfactorily fixed on the protective substrate by curing the adhesive.

According to a ninth aspect of the present invention, in the eighth aspect, in the step of curing the adhesive, the adhesive is cured by heating the adhesive to a normal temperature or a predetermined temperature and holding the adhesive for a predetermined time. The liquid jet head manufacturing method includes at least a curing step.
In the ninth aspect, the adhesive is cured well and the driving IC is securely bonded and fixed to the protective substrate.

According to a tenth aspect of the present invention, in the ninth aspect, the step of curing the adhesive includes an ultraviolet curing step in which the adhesive is cured by irradiating the adhesive with ultraviolet rays. Is in the way.
In the tenth aspect, the adhesive can be cured in a relatively short time by preventing the adhesive from sticking out by curing the adhesive in combination with the heat bonding step and the ultraviolet curing step. Can do.

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, and FIG. 2 is a plan view of the ink jet recording head according to the first embodiment and a sectional view taken along line AA ′. 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 1 to 2 μm. The elastic membrane 50 is provided.

  The flow path forming substrate 10 is provided with a plurality of pressure generating chambers 12 which are formed by anisotropic etching from the other side and are partitioned by a partition wall 11. Further, on the outer side in the longitudinal direction of the pressure generation chamber 12, a communication portion 13 constituting a part of the reservoir 100 serving as a common ink chamber for each pressure generation chamber 12 is formed. Are communicated with one end in the longitudinal direction via an ink supply path 14, respectively.

  Here, the anisotropic etching is performed by utilizing the difference in etching rate of the silicon single crystal substrate. For example, in this embodiment, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, the first (111) plane perpendicular to the (110) plane is gradually eroded, and the first (111) plane. And a second (111) plane that forms an angle of about 70 degrees with the (110) plane and an angle of about 35 degrees appears, and the (111) plane is compared with the etching rate of the (110) plane. This is performed using the property that the etching rate is about 1/180. By this anisotropic etching, precision processing can be performed based on the parallelogram depth processing formed by two first (111) surfaces and two oblique second (111) surfaces. The pressure generating chambers 12 can be arranged with high density.

  In the present embodiment, the long side of each pressure generating chamber 12 is formed by the first (111) plane and the short side is formed by the second (111) plane. The pressure generation chamber 12 is formed by etching until it substantially passes through the flow path forming substrate 10 and reaches the elastic film 50. Here, the amount of the elastic film 50 that is affected by the alkaline solution for etching the silicon single crystal substrate is extremely small. 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 kept constant. is doing.

  The thickness of the flow path forming substrate 10 may be selected in accordance with the arrangement density of the pressure generating chambers 12, and the arrangement density of the pressure generating chambers 12 is, for example, 180 per inch ( If it is about 180 dpi), the thickness of the flow path forming substrate 10 may be about 220 μm. However, for example, when arranged at a relatively high density of 200 dpi or more, the thickness of the flow path forming substrate 10 is It is preferable to make it relatively thin as 100 μm or less. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall 11 between the adjacent pressure generation chambers 12.

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 portion of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive or It is fixed via a heat welding 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 non-rust steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate from impact and external force. 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. In this case, since the deformation by heat of the flow path forming substrate 10 and the nozzle plate 20 is substantially the same, it can be easily joined using a thermosetting adhesive or the like.

  Here, the size of the pressure generation chamber 12 that applies ink droplet discharge pressure to the ink and the size of the nozzle opening 21 that discharges the ink droplet are optimized according to the amount of ink droplet to be discharged, the discharge speed, and the discharge frequency. The For example, when recording 360 ink droplets per inch, the nozzle opening 21 needs to be accurately formed with a diameter of several tens of μm.

  On the other hand, on the elastic film 50 opposite to the opening surface of the flow path forming substrate 10, the lower electrode film 60 with a thickness of, for example, about 0.2 μm and a thickness of, for example, about 0.5 to 5 μm. The piezoelectric layer 70 and the upper electrode film 80 having a thickness of, for example, about 0.1 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 any case, a piezoelectric active part is formed for each pressure generating chamber 12. 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 elastic film 50 and the lower electrode film 60 act as a diaphragm. In addition, each upper electrode film 80 that is an individual electrode of the piezoelectric element 300 is connected to a lead electrode 90 made of, for example, gold (Au) or the like and having one end extending to a region facing the ink supply path 14. .

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a protective substrate 30 having a piezoelectric element holding portion 31 capable of ensuring a space that does not hinder its movement in a region facing the piezoelectric element 300 is provided. It is joined. 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. In addition, this piezoelectric element holding | maintenance part 31 is provided for every row | line | column of the piezoelectric element 300 arranged in parallel. The protective substrate 30 is provided with a reservoir portion 32 constituting at least a part of the reservoir 100 for each row of the pressure generating chambers 12. In the present embodiment, these reservoir portions 32 are formed through the protective substrate 30 in the thickness direction and across the width direction of the pressure generation chamber 12, and through the communication holes provided in the elastic film 50. Reservoirs 100 that are in communication with the communication portion 13 of the flow path forming substrate 10 and serve as a common ink chamber for each row of the pressure generating chambers 12 are respectively configured. A through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 31 and the reservoir portion 32 of the protective substrate 30. The lead electrode 90 drawn from each piezoelectric element 300 is exposed in the through hole 33 in the vicinity of its end. Examples of such a protective substrate 30 include glass, a ceramic material, a metal, a resin, and the like, but it is more preferable that the protective substrate 30 is 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.

  Further, an insulating film 35 made of, for example, silicon dioxide is provided on the surface of the protective substrate 30, that is, the surface opposite to the bonding surface with the flow path forming substrate 10, and on the insulating film 35, A driving IC (semiconductor integrated circuit) 120 for driving the piezoelectric element 300 is mounted. Specifically, drive wiring 130 for controlling the drive IC 120 is formed in a predetermined pattern on the insulating film 35 on the surface of the protective substrate 30. The driving IC 120 is fixed on the driving wiring 130 with an insulating adhesive 140, and the driving IC 120 and each driving wiring 130 are electrically connected by a first connection wiring 151 made of a bonding wire. Each piezoelectric element 300 and the driving IC 120 are electrically connected by a lead electrode 90 drawn from each piezoelectric element 300 and a second connection wiring 152 made of a bonding wire and extending into the through hole 33. ing.

  Here, a granular insulator 141 having a certain size is mixed in the adhesive 140 for bonding the driving IC 120 onto the driving wiring 130. For this reason, when the drive IC 120 is bonded, the drive wiring 130 and the drive IC 120 do not come into contact with each other. That is, as shown in FIG. 2B, since the granular insulator 141 exists between the driving IC 120 and the driving wiring 130, they do not come into contact with each other, and a short circuit between them can be prevented.

  The particle size (average particle size) of the insulator 141 is preferably larger than the thickness of the drive wiring 130. For example, in this embodiment, the thickness of the drive wiring 130 is 1 to 3 μm, whereas the particle size of the insulator 141 is about 5 μm. As a result, as shown in FIG. 3, even when the insulator 141 enters between the drive wirings 130, the drive IC 120 and the drive wiring 130 do not come into contact with each other, and the two are reliably prevented from coming into contact with each other. be able to.

Examples of the material of the insulator 141 include resin materials such as hard plastic, silicon oxide (SiO _x ), silicon nitride (SiN), tantalum oxide (TaO _x ), and the like. It is preferable that the thermal expansion coefficient of the material used for the substrate 30 is close. For example, in this embodiment, since the protective substrate 30 is made of a silicon single crystal substrate, a granular insulator 141 made of silicon dioxide (SiO ₂ ) is mixed with the adhesive 140. Accordingly, even when heated at the time of bonding, the occurrence of warpage or the like due to the difference in the thermal expansion coefficient of the insulator 141 mixed in the protective substrate 30 and the adhesive 140 is prevented, so that the protective substrate 30 (drive wiring 130) And the driving IC 120 can be satisfactorily bonded.

  Furthermore, the particle shape of the insulator 141 is preferably spherical. Accordingly, the drive IC 120 is not adhered in a tilted state regardless of the direction of each particle of the insulator 141. Therefore, when the drive IC 120 and the drive wiring 130 are connected by wire bonding, that is, when the first connection wiring 151 that connects the drive IC 120 and the drive wiring 130 is formed, a connection failure occurs. Can be prevented. Note that the particle shape of the insulator 141 may be a polygon as shown in FIG. 4 as long as the particle size of each particle is uniform, but the length of each side is constant, such as a cube. It is desirable that

  And it is preferable that such an insulator 141 is mixed with the adhesive agent 140 in the ratio of 0.1 weight%-30 weight%, It is 0.1 weight%-10 weight% suitably. If the amount of the insulator 141 mixed is too small, for example, when the insulator 141 is not evenly mixed, the drive IC 120 is tilted and fixed, causing a connection failure of the first connection wiring 151. In addition, when the amount of the insulator 141 mixed is too large, warping or the like may occur due to a difference in thermal expansion coefficient between the driving IC 120 or the protective substrate 30 and the insulator 141. For this reason, it is preferable that the insulator 141 is mixed with the adhesive 140 at the above-described ratio.

  As described above, according to the present invention, the driving IC 120 is bonded and fixed by the adhesive 140 in which the granular insulator 141 is mixed on the driving wiring 130 provided on the surface of the protective substrate 30. And the drive wiring 130 can be reliably prevented. Further, the drive IC 120 can be satisfactorily bonded and fixed by controlling the amount of warping of the protective substrate 30 and the like by the material and the mixing amount of the insulator 141.

  The method of applying the adhesive 140 mixed with the insulator 141 is not particularly limited, but it is preferable to apply the adhesive formed with a predetermined thickness to the surface of the protective substrate 30 by transfer. . This makes it possible to reliably form the adhesive 140 in which the insulator 141 is mixed relatively uniformly with a predetermined thickness, rather than directly applying the adhesive to the surface of the protective substrate 30 with a dispenser or the like. Can be fixed well. In addition, the thickness of the adhesive 140 at the time of application | coating should just be more than the thickness of the drive wiring 130, and should just be suitably determined according to the particle size of the insulator 141 mixed, for example, 3 to 3 It is preferably about 10 μm. This is because if the adhesive 140 is too thin, the drive IC 120 cannot be securely fixed, and if the adhesive 140 is too thick, there is a possibility that misalignment or the like may occur when the drive IC 120 is fixed.

  The applied adhesive 140 is preferably cured at room temperature or by a thermosetting process in which the adhesive 140 is heated to a predetermined temperature, for example, about 65 ° C. and held for a predetermined time. As a result, the adhesive 140 can be cured satisfactorily, and the drive IC 120 can be reliably fixed at a predetermined position. Furthermore, you may make it combine the ultraviolet curing process which hardens the adhesive agent 140 by ultraviolet irradiation. Thereby, the hardening time of the adhesive agent 140 can be shortened and manufacturing efficiency improves.

  In particular, when the adhesive 140 is cured by heating, it is preferable to combine these thermosetting process and ultraviolet curing process. That is, when the adhesive 140 is heated and cured, the viscosity of the adhesive 140 is once reduced, and thus the adhesive 140 may protrude. For this reason, it is desirable to cure the adhesive 140 instantaneously to some extent by ultraviolet irradiation, and then heat and cure the adhesive 140. As a result, the adhesive 140 can be prevented from sticking out, and the adhesive 140 can be cured well in a relatively short time.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded to a region corresponding to the reservoir portion 32 of 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). The sealing film 41 seals one surface of the reservoir portion 32. 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. Has been.

  The ink jet recording head of the present embodiment described above takes in ink from an ink supply means (not shown), fills the interior from the reservoir 100 to the nozzle opening 21, and then generates pressure according to the drive signal from the drive IC 120. By applying a driving voltage between the lower electrode film 60 and the upper electrode film 80 corresponding to the chamber 12 and displacing the elastic film 50, the lower electrode film 60, and the piezoelectric body layer 70, each pressure generating chamber 12. The internal pressure increases and ink droplets are ejected from the nozzle openings 21.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to the above-mentioned embodiment. For example, in the above-described embodiment, the thin film type ink jet recording head manufactured by applying the film forming and lithography processes is taken as an example. However, the present invention is not limited to this. For example, a green sheet is pasted. The present invention can also be applied to a thick film type ink jet recording head formed by such a method.

  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. 5 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 5, 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 not-shown paper feed roller, is conveyed onto 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 manufacturing 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. 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 Elastic film, 60 lower electrode film, 70 piezoelectric layer, 80 upper electrode film, 100 reservoir, 120 drive IC, 130 drive wiring, 140 adhesive, 141 insulator, 151 first connection wiring, 152 second connection wiring, 300 piezoelectric element

Claims (9)

A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, and a pressure plate is provided on one surface side of the flow path forming substrate via a vibration plate to cause a pressure change in the pressure generating chamber. A piezoelectric element, a protective substrate having a piezoelectric element holding portion that is bonded to the surface of the flow path forming substrate on the piezoelectric element side and protects the piezoelectric element, and provided on the protective substrate to drive the piezoelectric element A liquid ejecting head having a driving IC for
The drive IC is fixed on the drive wiring formed on the surface of the protective substrate by an adhesive, and the drive IC and the drive wiring are connected by a connection wiring made of a bonding wire, and the adhesive A liquid ejecting head, wherein a granular insulator larger than the thickness of the drive wiring is mixed . The liquid ejecting head according to claim 1, wherein the insulator has a spherical shape. The liquid ejecting head according to claim 1, wherein the insulator is silicon oxide, silicon nitride, or tantalum oxide. The liquid ejecting head according to claim 1, wherein the insulator is made of a resin material. 5. The liquid jet head according to claim 1, wherein the insulator is mixed with the adhesive at a ratio of 0.1 wt% to 30 wt%. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1. A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, and a pressure plate is provided on one surface side of the flow path forming substrate via a vibration plate to cause a pressure change in the pressure generating chamber. A piezoelectric element, a protective substrate having a piezoelectric element holding portion that is bonded to the surface of the flow path forming substrate on the piezoelectric element side and protects the piezoelectric element, and fixed on the protective substrate to drive the piezoelectric element And a liquid ejecting head manufacturing method comprising:
A step of applying an adhesive mixed with a granular insulator larger than the thickness of the driving wiring on the surface of the protective substrate on which the driving wiring is formed, and mounting the driving IC on the adhesive And a step of curing the adhesive. 8. The step of curing the adhesive according to claim 7, further comprising a thermosetting step of curing the adhesive by heating the adhesive to normal temperature or a predetermined temperature and holding the adhesive for a predetermined time. A method for manufacturing a liquid jet head. 9. The method of manufacturing a liquid jet head according to claim 8, wherein the step of curing the adhesive includes an ultraviolet curing step of irradiating the adhesive with ultraviolet rays to cure.

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