JP2005053117A - Liquid ejection head, its manufacturing process, and liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection head having enhanced print quality and reliability, and to provide its manufacturing process and a liquid ejector. <P>SOLUTION: On the side of a reservoir forming substrate 30 opposite to a channel forming substrate 10, a liquid inlet forming plate 40 provided with a liquid inlet 44 communicating with a reservoir section 31 is formed. At least in the vicinity of the opening of the reservoir section 31 on the liquid inlet forming plate 40 side, a protrusion 33 is provided to protrude up to halfway in the opening from the sidewall of the reservoir section 31. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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. The present invention relates to an ink jet recording head in which a piezoelectric element is provided via an ink jet and ink droplets are ejected by displacement of the piezoelectric element, 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. Inkjet recording heads have been put into practical use. As such an ink jet recording head, for example, a flow path forming substrate provided with a plurality of pressure generation chambers communicating with nozzle openings, a piezoelectric element that causes a pressure change in each pressure generation chamber, and a pressure generation chamber A configuration comprising a reservoir forming substrate provided with a reservoir portion constituting at least a part of a reservoir which is a common liquid chamber, and a nozzle plate having a nozzle opening joined to the other surface side of the flow path forming substrate. Are known. Also, a piezoelectric element holding portion capable of sealing the space is provided in a region facing the piezoelectric element of the reservoir forming substrate in a state where a space that does not hinder the movement of the piezoelectric element is secured. An ink supply path for supplying ink in the reservoir to each pressure generating chamber is provided on one end side in the longitudinal direction of each pressure generating chamber (see, for example, Patent Document 1).

  However, the compliance substrate is bonded to the opening of the reservoir portion provided on the reservoir forming substrate as a liquid inlet forming plate that closes the opening of the reservoir and includes an ink inlet that supplies ink to the reservoir. When the air bubbles remaining in the ink enter the reservoir section, the air bubbles easily collect in the corner defined by the side wall of the pressure generation chamber extending in the column direction of the pressure generation chamber of the reservoir section and the compliance substrate. Bubbles tend to accumulate at the corners at both ends in the row direction of the pressure generation chambers at the corners. If the air bubbles accumulated in the reservoir portion are ejected from the nozzle opening together with the ink during printing, there is a problem that an ink ejection failure occurs and the print quality is deteriorated. Such a problem exists not only in the ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject ink other than ink.

JP 2000-296616 A (paragraph [0100], FIGS. 1 and 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 have improved printing quality and reliability.

According to a first aspect of the present invention for solving the above problems, a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for discharging droplets is defined, and a diaphragm on one surface side of the flow path forming substrate. A piezoelectric element that is provided in a region corresponding to the pressure generation chamber via the pressure generation chamber and causes a pressure change in the pressure generation chamber; and a longitudinal direction of the pressure generation chamber that is bonded to the piezoelectric element side of the flow path forming substrate And a reservoir forming substrate provided with a reservoir portion penetrating in a thickness direction and constituting a part of a reservoir that communicates with one end portion and supplies liquid, wherein the flow of the reservoir forming substrate is A liquid introduction port forming plate provided with a liquid introduction port communicating with the opening of the reservoir portion is formed on the side opposite to the path forming substrate, and at least the opening portion of the reservoir portion on the liquid introduction port formation plate side In the vicinity, A liquid-jet head, wherein a projection protruding so pushed out from the side wall of the bar portion to the middle of the inner said opening is provided.
In the first aspect, by providing the protrusion in the region where the air bubbles stay most in the reservoir portion, the bubbles contained in the liquid do not stay in the reservoir portion when the liquid is taken in from the liquid supply port.

According to a second aspect of the present invention, in the first aspect, the protrusion formed in the vicinity of the opening of the reservoir portion of the reservoir forming substrate is provided over the entire row direction of the pressure generating chambers. In the liquid ejecting head,
In the second aspect, the protrusion can be easily formed with high accuracy in the reservoir portion, and the retention of bubbles can be prevented.

According to a third aspect of the present invention, in the first aspect, the projecting portions formed in the vicinity of the opening of the reservoir portion of the reservoir forming substrate have both end portions of a region corresponding to the row direction of the pressure generating chambers. The liquid ejecting head is provided only in the liquid ejecting head.
In the third aspect, since the protrusions are provided only in the region corresponding to the row direction of the pressure generation chambers, the shape of the reservoir forming substrate at the location where bubbles tend to stay may be changed within a minimum range.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the protrusion is provided only on the opening side in the thickness direction of the reservoir portion. In the head.
In the fourth aspect, the protrusion can be easily and highly accurately formed in the region where the bubbles are most retained in the reservoir.

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 protrusion is provided over a thickness direction of the reservoir.
In the fifth aspect, it is possible to reliably prevent bubbles from staying in the reservoir portion by the protrusion.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the reservoir forming substrate is made of single crystal silicon, and the reservoir portion and the protrusion are etched from both sides. The liquid ejecting head is characterized in that there is.
In the sixth aspect, the reservoir portion and the protrusion can be formed simultaneously and with high accuracy.

A seventh aspect of the invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to sixth aspects.
In the seventh aspect, it is possible to realize a liquid ejecting apparatus having substantially stable liquid ejection characteristics and improved reliability.

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 discharging droplets is defined, and the pressure on one side of the flow path forming substrate via a diaphragm. A piezoelectric element provided in a region corresponding to the generation chamber and causing pressure change in the pressure generation chamber; and joined to the piezoelectric element side of the flow path forming substrate and communicated with one longitudinal end of the pressure generation chamber A reservoir forming substrate provided with a reservoir portion penetrating in a thickness direction constituting a part of a reservoir for supplying liquid, and formed on the opposite side of the reservoir forming substrate to the flow path forming substrate, A liquid ejecting head manufacturing method comprising a liquid introducing port forming plate provided with a liquid introducing port for supplying a liquid to a reservoir unit, wherein a mask film is formed on both surfaces of the reservoir forming substrate, Each of the mask films In addition, the reservoir portion is formed by forming openings that are partially different from each other in the position of the opposite edges in the thickness direction of the reservoir portion, and etching from both surfaces of the reservoir forming substrate through the mask film. And a protrusion protruding so as to protrude from the side wall of the reservoir part to the middle of the opening part at least in the vicinity of the opening of the reservoir part on the liquid introduction port forming plate side. In the manufacturing method.
In the eighth aspect, the reservoir and the protrusion can be formed simultaneously and with high accuracy without increasing the number of steps for forming the protrusion.

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 of FIG. As shown in the drawing, 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. A 2 μm elastic film 50 is formed.

  This flow path forming substrate 10 is formed with a pressure generating chamber 12 partitioned by a plurality of partition walls 11 by anisotropic etching from the other side using the protective film 51 as a mask. Further, on the outer side in the longitudinal direction of the pressure generating chambers 12 in each row, a reservoir 100 that communicates with a reservoir portion 31 provided on a reservoir forming substrate 30 that becomes a bonding substrate, which will be described later, and serves as a common ink chamber for each pressure generating chamber 12. The communication part 13 which comprises is formed. The communication portion 13 is in communication with one end portion in the longitudinal direction of each pressure generating chamber 12 via the ink supply path 14.

  The ink supply path 14 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and has a smaller cross-sectional area than the pressure generation chamber 12. For example, in the present embodiment, the ink supply path 14 has a width smaller than the width of the pressure generation chamber 12 by narrowing the flow path on the pressure generation chamber 12 side between the reservoir 100 and each pressure generation chamber 12 in the width direction. It is formed with. As described above, in this embodiment, the ink supply path 14 is formed by narrowing the width of the flow path from one side. However, the ink supply path may be formed by narrowing the width of the flow path from both sides.

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 thickness of the flow path forming substrate 10 may be selected as the optimum thickness according to 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 between adjacent pressure generation chambers 12. In the present embodiment, as will be described in detail later, the thickness of the flow path forming substrate 10 is set to 70 μm.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. The nozzle plate 20 has a thickness of, for example, 0.05 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 that is the flow path forming substrate 10 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 side opposite to the opening surface of the flow path forming substrate 10, an insulating film 55 having a thickness of, for example, about 0.4 μm is disposed on the elastic film 50 having a thickness of, for example, about 1.0 μm. A lower electrode film 60 having a thickness of about 0.2 μm, a piezoelectric layer 70 having a thickness of about 1.0 μm, and an upper electrode film 80 having a thickness of about 0.05 μm, for example. The piezoelectric element 300 is formed by being laminated by a process described later. 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 lower electrode film 60, the elastic film 50, and the insulating film 55 of the piezoelectric element 300 function as a diaphragm. Further, a lead electrode 90 made of, for example, gold (Au) is extended from the vicinity of one end in the longitudinal direction of the upper electrode film 80 of the piezoelectric element 300 to the vicinity of the end of the pressure generation chamber 12 of the flow path forming substrate 10. Yes. The lead electrode 90 is electrically connected to a drive IC (not shown) near the end of the flow path forming substrate 10.

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, that is, on the lower electrode film 60, the insulating film 55, and the lead electrode 90, a reservoir unit 31 constituting at least a part of the reservoir 100 is provided. The reservoir forming substrate 30 is bonded via an adhesive. In this embodiment, the reservoir portion 31 is formed across the reservoir forming substrate 30 in the thickness direction and across the width direction of the pressure generating chamber 12, and as described above, the communication portion of the flow path forming substrate 10 is formed. The reservoir 100 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12.

  Further, on the side opposite to the flow path forming substrate 10 of the reservoir unit 31, a liquid introduction port provided with an ink introduction port 44 that closes an opening of the reservoir unit 31, which will be described in detail later, and supplies ink to the reservoir unit 31. A compliance substrate 40 is bonded as a forming plate. And the area where the bubbles are most likely to accumulate in the reservoir portion 31, in this embodiment, the corner portion defined by the compliance substrate 40 and the side wall of the reservoir portion 31 on the side of the pressure generating chamber 12 extending in the row direction. A protruding portion 33 protruding so as to protrude like a bowl from the side wall of the reservoir portion 31 to the middle of the opening portion of the reservoir portion 31 is provided over the entire pressure generation chamber 12 in the row direction. This protrusion 33 reliably prevents bubbles from staying in the reservoir 31. In the present embodiment, the protrusion 33 has a triangular prism shape in which the longitudinal section of the pressure generating chamber 12 is triangular, and is provided only on the opening side of the side wall of the reservoir 31.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region facing the piezoelectric element 300 of the reservoir forming substrate 30. Examples of such reservoir forming substrate 30 include glass, ceramic, metal, plastic, and the like, but it is more preferable to use a material that is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. The silicon single crystal substrate having the same material as the flow path forming substrate 10 and having a thickness of about 400 μm was used. As will be described in detail later, in this embodiment, the reservoir portion 31 and the protrusion 33 are formed by etching the reservoir forming substrate 30 made of a silicon single crystal substrate from both sides.

  On such a reservoir forming substrate 30, a compliance substrate 40 is bonded as a liquid introducing port forming plate provided with an ink introducing port 44 for closing the opening of the reservoir unit 31 and supplying ink to the reservoir unit 31. . The compliance substrate 40 includes a sealing film 41 and a fixing plate 42. 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 one surface of the reservoir portion 31 is sealed by the sealing film 41. Has been. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  In addition, an ink introduction port 44 for supplying ink to the reservoir 100 is formed in a region of the compliance substrate 40 facing the reservoir portion 31. The ink introduction port 44 is provided on the side opposite to the pressure generation chamber 12 side with the protrusion 33 interposed therebetween. In such an ink jet recording head of this embodiment, ink is taken in from an ink introduction port 44 connected to an external ink supply means (not shown), and the interior is filled with ink from the reservoir 100 to the nozzle opening 21. In accordance with the recording signal from each, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the insulating film 55, the lower electrode film 60, and the piezoelectric layer 70 , The pressure in each pressure generating chamber 12 increases, and ink droplets are ejected from the nozzle openings 21.

  In this way, by providing the protrusion 33 in the region where the air bubbles stay most in the reservoir portion 31, the bubbles contained in the ink stay in the reservoir portion 31 when the ink is taken in from the ink introduction port 44. Therefore, bubbles accumulated in the reservoir unit 31 are not ejected together with ink from the nozzle openings 21 during printing, and the printing quality and reliability can be improved. Further, in the present embodiment, since the protrusions 33 are provided only at the corners of the reservoir portion 31, the elastic deformation of the compliance substrate 40 is not restricted by the protrusions 33, and compliance by the compliance substrate 40 is ensured. Can do.

  The manufacturing method of the ink jet recording head of the present embodiment described above will be described in detail with reference to FIGS. 3 to 5 and 7 are cross-sectional views showing a method for manufacturing an ink jet recording head. First, as shown in FIG. 3A, an elastic film 50 made of silicon dioxide is formed by thermally oxidizing a silicon single crystal substrate to be the flow path forming substrate 10 in a diffusion furnace at about 1100 ° C. At this time, the elastic film 50 is formed on one surface, and the protective film 51 used as a mask pattern in a subsequent process is formed on the other surface. Next, as shown in FIG. 3B, an insulating film 55 made of zirconium oxide or the like is formed on the elastic film 50.

  Next, as shown in FIG. 3C, for example, a lower electrode film 60 made of platinum and iridium is formed on the entire surface of the insulating film 55 and then patterned into a predetermined shape. Next, as shown in FIG. 3D, a piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) and an upper electrode film 80 made of, for example, iridium are sequentially stacked and patterned simultaneously. Thus, the piezoelectric element 300 is formed. Next, as shown in FIG. 3E, lead electrodes 90 are formed. Specifically, for example, a lead electrode 90 made of gold (Au) or the like is formed over the entire surface of the flow path forming substrate 10 and patterned for each piezoelectric element 300. The above is the film forming process.

  Next, a method for manufacturing the reservoir forming substrate 30 bonded to the flow path forming substrate 10 will be described. First, as shown in FIG. 4A, a silicon single crystal substrate serving as a reservoir forming substrate 30 is thermally oxidized in a diffusion furnace at about 1100 ° C. to form a silicon dioxide layer, and silicon dioxide layers provided on both sides are formed. By respectively patterning, mask films 34 and 35 having openings 34a and 35a on both surfaces are formed. The opening 35 a of the mask film 35 is formed to have the same size as the opening on the flow path forming substrate 10 side of the reservoir section 31, and the opening 34 a of the mask film 34 extends in the column direction of the pressure generation chamber 12. The pressure generating chamber 12 side of the edge is shifted so as to be inside the opening edge of the opening 35a, and the other opening edges are formed so that the positions facing the opening 35a are the same.

Next, as shown in FIG. 4B to FIG. 5B, the reservoir forming substrate 30 is subjected to anisotropic etching with an alkaline solution from both sides of the reservoir forming substrate 30 through the mask films 34 and 35. The reservoir portion 31 and the protrusion 33 are formed in the upper portion. Specifically, when the reservoir forming substrate 30 made of a silicon single crystal substrate is immersed in an alkaline solution such as KOH, it is gradually eroded from the openings 34a and 35a on both surfaces of the reservoir forming substrate 30, as shown in FIG. A first (111) plane perpendicular to the (110) plane, and a second angle that forms an angle of about 70 degrees with the first (111) plane and an angle of about 35 degrees with the (110) plane. The (111) plane appears, and concave portions 36 defined by the first (111) plane and the second (111) plane are formed on both surfaces of the reservoir forming substrate 30. Then, if etching is continued, as shown in FIG. 4C, the bottom surfaces of the concave portions 36 on both sides communicate with each other, and a side wall whose cross section protrudes in a triangular shape is formed by the second (111) surface. Further, when etching is continued, as shown in FIG. 5A, surfaces perpendicular to the surface gradually appear on both surface sides of the reservoir forming substrate 30. Finally, as shown in FIG. 5B, the side walls having the same opening edge portions facing each other in the thickness direction of the reservoir forming substrate 30 are perpendicular to the surface. In addition, the side walls in which the positions of the opening edge portions facing each other in the thickness direction of the reservoir forming substrate 30 are a surface perpendicular to the surface on the mask film 35 side and a surface inclined on the mask film 34 side. Thereby, the reservoir part 31 and the protrusion 33 are formed.
In practice, the openings 34a and 35a of the mask films 34 and 35 are shown in FIG. 6 so as to form a vertical side wall in the column direction of the pressure generating chamber 12 as the reservoir 31. Thus, the mask pattern is formed in a comb blade shape at a predetermined inclination angle.

  In this way, the opening edge on the pressure generating chamber 12 side extending in the column direction of the pressure generating chamber 12 of the opening 34 a of the mask film 34 used when etching from both sides to form the reservoir portion 31 on the reservoir forming substrate 30. By projecting the portion to the inside of the opening 35 a of the mask film 35, the protrusion 33 can be simultaneously formed when the reservoir portion 31 is formed. Thereby, the process of forming the protrusion 33 separately becomes unnecessary, and the protrusion 33 can be formed easily and with high accuracy without complicating the manufacturing process.

  The formation of the reservoir portion 31 and the protrusion 33 may be performed before the piezoelectric element holding portion 32 is formed on the reservoir forming substrate 30 or after the piezoelectric element holding portion 32 is formed. . For example, when the reservoir portion 31 and the protrusion 33 are formed after the piezoelectric element holding portion 32 is formed, the protective film is prevented from being etched simultaneously when forming the reservoir portion 31 and the protrusion 33 on the inner surface of the piezoelectric element holding portion 32. Etc. must be formed. Similarly, when the piezoelectric element holding portion 32 is formed after the reservoir portion 31 and the protrusion 33 are formed, it is necessary to form a protective film or the like on the inner surfaces of the reservoir portion 31 and the protrusion 33. The piezoelectric element holding part 32 can be formed by adjusting the etching time (half etching).

  Next, as shown in FIG. 7A, the reservoir forming substrate 30 formed with the reservoir portion 31, the piezoelectric element holding portion 32, and the protrusion 33 is bonded to the flow path forming substrate 10 on the piezoelectric element 300 side. In the present embodiment, the flow path forming substrate 10 and the reservoir forming substrate 30 are bonded with, for example, a thermosetting epoxy adhesive. The flow path forming substrate 10 and the reservoir forming substrate 30 are not limited to bonding via an adhesive. For example, a film made of gold (Au) is formed on each of the bonding surfaces, and the two are bonded to each other by gold-gold bonding. Alternatively, it may be bonded by anodic bonding.

  Next, as shown in FIG. 7B, anisotropic etching of the silicon single crystal substrate with the alkali solution described above is performed to form the pressure generating chamber 12, the communication portion 13, the ink supply path 14, and the like. In practice, a large number of chips are simultaneously formed on a single silicon wafer by the above-described series of film formation and anisotropic etching, and after the completion of the process, the nozzle plate 20 and the compliance substrate 40 are bonded. Then, the ink jet recording head is obtained by dividing the flow path forming substrate 10 of one chip size as shown in FIG.

(Embodiment 2)
FIG. 8 is a plan view of an ink jet recording head according to the second embodiment and a cross-sectional view thereof taken along the line BB ′. As shown in the figure, the reservoir forming substrate 30A of the present embodiment includes a pressure at a corner defined by the compliance substrate 40 and a side wall of the reservoir portion 31A on the side of the pressure generating chamber 12 extending in the column direction. Protrusions 33 </ b> A protruding so as to protrude in a bowl shape are provided at the corners at both ends in the row direction of the generation chamber 12.

  As described above, since the flange-shaped protrusion 33A for preventing the bubble retention is formed only in the portion where the bubbles are most likely to stay, the ratio of the formation area of the protrusion 33A to the compliance area can be minimized. It is possible to prevent air bubbles from being retained while ensuring sufficient compliance. In addition, the protrusion 33A can be easily and highly accurately formed at the same time as the reservoir 31A by shifting the positions of the openings 34a and 35b of the mask film when forming the reservoir 31A. Can do.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above. For example, in Embodiments 1 and 2 described above, the protrusions 33 and 33A are provided on the side of the reservoir portions 31 and 31A on the side of the opening where the compliance substrate 40 is joined. The projecting portion may be provided over the thickness direction of the reservoir portion.
Further, for example, in the above-described embodiment, a thin film type ink jet recording head manufactured by applying a film forming and lithography process is taken as an example. However, the present invention is not limited to this. For example, a green sheet is used. The present invention can also be applied to a thick film type ink jet recording head formed by a method such as sticking.

  In addition, the ink jet recording heads of these embodiments constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are 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 addition, although the ink jet recording head and the ink jet recording apparatus that discharge ink as the liquid ejecting head have been described as examples, the present invention is widely intended for the liquid ejecting head and the liquid ejecting apparatus in general. Examples of the liquid ejecting head include a recording head used in an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (surface emitting display). Electrode material ejecting heads used in manufacturing, bioorganic matter ejecting heads used in biochip production, and the like.

FIG. 2 is a perspective view illustrating an outline of a recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. 5 is a cross-sectional view 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. FIG. 3 is a bottom view of the reservoir forming substrate according to the first embodiment. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 6A and 6B are a plan view and a cross-sectional view of a recording head according to Embodiment 2. 1 is a schematic view of an ink jet recording apparatus according to an embodiment.

Explanation of symbols

  10 flow path forming substrate, 12 pressure generating chamber, 20 nozzle plate, 21 nozzle opening, 30, 30A reservoir forming substrate, 31, 31A reservoir portion, 32 piezoelectric element holding portion, 33, 33A protrusion, 40 compliance substrate, 60 bottom Electrode film, 70 piezoelectric layer, 80 upper electrode film, 90 extraction electrode, 100 reservoir, 300 piezoelectric element

Claims (8)

A flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening for discharging droplets is defined, and a surface corresponding to the pressure generating chamber is provided on one surface side of the flow path forming substrate via a vibration plate. A piezoelectric element that causes a pressure change in the pressure generating chamber, and a part of a reservoir that is bonded to the piezoelectric element side of the flow path forming substrate and that communicates with one longitudinal end of the pressure generating chamber to supply liquid And a reservoir forming substrate provided with a reservoir portion penetrating in the thickness direction constituting the liquid jet head,
On the opposite side of the reservoir forming substrate from the flow path forming substrate, a liquid introducing port forming plate provided with a liquid introducing port communicating with the opening of the reservoir portion is formed, and on the liquid introducing port forming plate side A liquid ejecting head characterized in that a protrusion is provided at least in the vicinity of the opening of the reservoir so as to protrude from the side wall of the reservoir to the middle of the opening. The liquid ejecting head according to claim 1, wherein the protrusion formed in the vicinity of the opening of the reservoir portion of the reservoir forming substrate is provided over the entire row direction of the pressure generating chamber. 2. The projection according to claim 1, wherein the protrusion formed in the vicinity of the opening of the reservoir portion of the reservoir forming substrate is provided only at both ends of a region corresponding to the column direction of the pressure generating chamber. Liquid ejecting head. The liquid ejecting head according to claim 1, wherein the protrusion is provided only on the opening side in the thickness direction of the reservoir. The liquid ejecting head according to claim 1, wherein the protrusion is provided across a thickness direction of the reservoir. 6. The liquid ejecting head according to claim 1, wherein the reservoir forming substrate is made of single crystal silicon, and the reservoir portion and the protrusion are formed by etching from both sides. 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 discharging droplets is defined, and a surface corresponding to the pressure generating chamber is provided on one surface side of the flow path forming substrate via a vibration plate. A piezoelectric element that causes a pressure change in the pressure generating chamber, and a part of a reservoir that is bonded to the piezoelectric element side of the flow path forming substrate and that communicates with one longitudinal end of the pressure generating chamber to supply liquid A reservoir forming substrate provided with a reservoir portion penetrating in the thickness direction, and a liquid introduction unit that is formed on the opposite side of the reservoir forming substrate from the flow path forming substrate and supplies a liquid to the reservoir portion. A liquid ejecting head manufacturing method comprising a liquid introduction port forming plate provided with a mouth,
A mask film is formed on both surfaces of the reservoir forming substrate, and an opening is formed in each of the mask films on both surfaces, the opening portions being partially different from each other in positions opposite to each other in the thickness direction of the reservoir portion. Etching from both sides of the formation substrate through the mask film forms the reservoir portion and at least near the opening of the reservoir portion on the liquid inlet forming plate side from the side wall of the reservoir portion to the inside of the opening portion. A method of manufacturing a liquid ejecting head, comprising: forming a protruding portion protruding so as to protrude halfway.

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