JP4013029B2 - Inkjet recording head and inkjet recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an inkjet in which a part of a pressure generating chamber communicating with a nozzle opening for ejecting ink droplets is constituted by a diaphragm, and a piezoelectric element is provided through the diaphragm, and ink droplets are ejected by displacement of the piezoelectric element. The present invention relates to an ink jet recording head and an ink jet recording apparatus.
[0002]
[Prior art]
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.
[0003]
The former can change the volume of the pressure generation chamber by bringing the end face of the piezoelectric element into contact with the vibration plate, and it is possible to manufacture a head suitable for high-density printing, while the piezoelectric element is arranged in an array of nozzle openings. There is a problem that the manufacturing process is complicated because a difficult process of matching the pitch into a comb-like shape and an operation of positioning and fixing the cut piezoelectric element in the pressure generating chamber are necessary.
[0004]
On the other hand, the latter can flexibly vibrate, although a piezoelectric element can be built on the diaphragm by a relatively simple process of sticking a green sheet of piezoelectric material according to the shape of the pressure generation chamber and firing it. There is a problem that a certain amount of area is required for the use of, and high-density arrangement is difficult.
[0005]
On the other hand, in order to eliminate the inconvenience of the latter recording head, a uniform piezoelectric material layer is formed by a film forming technique over the entire surface of the diaphragm as seen in Japanese Patent Laid-Open No. 5-286131. A material in which a piezoelectric layer is formed so that a material layer is cut into a shape corresponding to a pressure generation chamber by a lithography method and is independent for each pressure generation chamber has been proposed.
[0006]
[Problems to be solved by the invention]
In such an ink jet recording head, a nozzle plate having a plurality of nozzle openings is joined to a flow path forming substrate in which a pressure generating chamber is formed. Since this nozzle plate is generally made of a material different from that of the flow path forming substrate, wiring is performed when the flow path forming substrate and the nozzle plate are bonded with a thermosetting adhesive or by wire bonding to the piezoelectric element. When connecting, there is a problem that the flow path forming substrate is deformed due to a difference in thermal expansion coefficient between the nozzle plate and the flow path forming substrate, and breakage such as cracking occurs.
[0007]
In particular, the vicinity of the peripheral edge of the flow path forming substrate is higher in rigidity than the central part where the pressure generating chamber is provided, so stress concentrates and breaks near the boundary between the high rigidity region and the low rigidity region. There is a problem that is likely to occur.
[0008]
In view of such circumstances, it is an object of the present invention to provide an ink jet recording head and an ink jet recording apparatus that prevent a flow path forming substrate from being broken.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention for solving the above-described problem, the pressure is formed via a flow path forming substrate in which a pressure generation chamber communicating with a nozzle opening is defined, and a diaphragm constituting a part of the pressure generation chamber. In an ink jet recording head provided with a piezoelectric element that is provided in a region facing the generation chamber and causes a pressure change in the pressure generation chamber, both ends in the column direction of the pressure generation chamber of the flow path forming substrate are A stress relaxation portion having reduced rigidity is provided by forming a plurality of recesses having a narrower width than the pressure generation chamber, and the recess is formed by etching simultaneously with the pressure generation chamber to reduce the width of the recess. The ink jet recording head is characterized in that the rigidity of the flow path forming substrate is changed by changing in a stepwise manner so that the end portion side of the flow path forming substrate becomes narrower.
[0010]
In the first aspect, by reducing the rigidity of the flow path forming substrate in a stepwise manner, stress concentration due to deformation of the flow path forming substrate can be prevented and cracking can be prevented. Further, the rigidity gradually increases toward the end of the flow path forming substrate, and stress concentration due to deformation of the flow path forming substrate is effectively prevented.
[0013]
In the second aspect of the present invention, the flow path forming substrate is formed with a communicating portion that communicates with each pressure generating chamber and forms at least a part of a reservoir serving as a common ink chamber of the pressure generating chamber, In the ink jet recording head according to the first aspect, the stress relaxation portion is formed inside or outside a region corresponding to an end portion of the communication portion in the column direction of the pressure generating chamber. is there.
[0014]
In the second aspect, the rigidity of the flow path forming substrate can be reduced without causing a crack in the flow path forming substrate along the concave portion constituting the stress relaxation portion.
[0017]
According to a third aspect of the present invention, there is provided the ink jet recording head according to the first or second aspect, wherein the width of each recess constituting the stress relaxation portion is narrower than the width of the pressure generating chamber.
[0018]
In the third aspect, the rigidity of the flow path forming substrate can be appropriately reduced without excessively reducing the rigidity of the flow path forming substrate.
[0019]
According to a fourth aspect of the present invention, the pressure generation chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and lithography. The ink jet recording head according to any one of the first to third aspects.
[0020]
In the fourth aspect, an ink jet recording head having high-density nozzle openings can be manufactured in a large amount and relatively easily.
[0021]
A fifth aspect of the present invention is an ink jet recording apparatus comprising the ink jet recording head according to any one of the first to fourth aspects.
[0022]
In the fifth aspect, it is possible to realize an ink jet recording apparatus with improved head ink ejection characteristics.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments.
[0024]
(Embodiment 1)
FIG. 1 is a perspective view of an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a top view and a cross-sectional view thereof.
[0025]
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 has a thickness of 1 made of silicon dioxide previously formed by thermal oxidation on one surface side thereof. An elastic film 50 of ˜2 μm is formed.
[0026]
The flow path forming substrate 10 is formed by anisotropic etching from the surface opposite to the elastic film 50, and a plurality of pressure generating chambers 12 substantially penetrating the flow path forming substrate 10 are formed in the width direction. It is installed side by side. Further, on the outer side in the longitudinal direction of the pressure generation chamber 12, a communication portion 14 that communicates with each pressure generation chamber 12 via the ink supply path 13 is formed. The communication portion 14 communicates with a reservoir portion of a reservoir forming substrate, which will be described later, and constitutes a part of the reservoir 100 that is a common ink chamber of the pressure generation chambers 12.
[0027]
In the present embodiment, the flow path forming substrate 10 is provided with two rows of pressure generation chambers 12 arranged in parallel in the width direction, and the pressure generation chambers 12 are arranged in a straight line in the longitudinal direction. It is provided with a slight shift in the width direction.
[0028]
In addition, on both outer sides of the row of the pressure generation chambers 12 of the flow path forming substrate 10, stress relaxation portions 16 including a plurality of recesses 15 arranged in parallel in the width direction of the pressure generation chambers 12 are provided.
[0029]
Each recess 15 constituting the stress relaxation portion 16 is provided so as to substantially penetrate the flow path forming substrate 10 and has a narrower width than the pressure generation chamber 12, similarly to the pressure generation chamber 12. In the present embodiment, the width of each recess 15 is narrower toward the end of the flow path forming substrate 10. That is, by changing the width of each recess 15 constituting the stress relaxation part 16 in a stepwise manner, the rigidity of the flow path forming substrate is changed so as to gradually increase toward the end side.
[0030]
Providing such a stress relaxation portion 16 can prevent cracks from occurring in the flow path forming substrate 10 as will be described in detail later.
[0031]
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.
[0032]
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. In addition, each ink supply path 13 communicating with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and the flow path resistance of the ink flowing into the pressure generation chamber 12 is kept constant. That is, the ink supply path 13 is formed by etching the silicon single crystal substrate halfway in the thickness direction (half etching). Half etching is performed by adjusting the etching time.
[0033]
Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 in which a nozzle opening 21 communicating in the vicinity of the end portion on the opposite side of each pressure generating chamber 12 and the ink supply path 13 is formed, for example, It is fixed by a heat curable adhesive. The nozzle plate 20 is made of non-rust steel having a thickness of 0.1 to 1 mm, for example. The nozzle plate 20 also covers the entire 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.
[0034]
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.
[0035]
On the other hand, on the elastic film 50 provided on the flow path forming substrate 10, 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 μm, For example, the upper electrode film 80 of about 0.1 μm is laminated and formed by a process described later to constitute the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator.
[0036]
Further, the upper electrode film 80 that is an individual electrode of the piezoelectric element 300 is connected to a drive wiring (not shown) via a lead electrode 90 that extends from the upper electrode film 80 to the elastic film 50.
[0037]
A reservoir forming substrate 30 having a reservoir portion 31 that constitutes a part of the reservoir 100 is joined to the flow path forming substrate 10 on the piezoelectric element 300 side. In this embodiment, the reservoir portion 31 is formed across the reservoir forming substrate 30 in the thickness direction and extending in the row direction of the pressure generating chambers 12, and as described above, the communicating portion of the flow path forming substrate 10 is formed. 14 is connected to the reservoir 100.
[0038]
As such a reservoir forming substrate 30, it is preferable to use a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, a ceramic material, etc., and in this embodiment, the same as the flow path forming substrate 10. The material silicon single crystal substrate was used. Thereby, both can be reliably bonded by high-temperature bonding using a thermosetting adhesive, and the manufacturing process can be simplified.
[0039]
Further, in a region facing the piezoelectric element 300 of the reservoir forming substrate 30, a piezoelectric element holding portion 32 capable of sealing the space is provided in a state where a space that does not hinder the movement of the piezoelectric element 300 is secured. The element 300 is sealed in the piezoelectric element holding portion 32.
[0040]
Further, in the reservoir forming substrate 30, a through-groove 37 penetrating in the thickness direction is arranged in parallel with the pressure generating chamber 12 in a region facing the vicinity of the end of the lead electrode 90 connected to the upper electrode film 80 of the piezoelectric element 300. It is provided over the installation direction. A drive wiring connected to a drive circuit (not shown) extends into the through groove 37 by, for example, wire bonding and is electrically connected to each lead electrode 90.
[0041]
In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded to the reservoir forming substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir unit 31. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Thus, the flexible portion 45 is deformable by a change in internal pressure.
[0042]
The ink jet recording head according to this embodiment takes in ink from an external ink supply unit (not shown), fills the interior from the reservoir 100 to the nozzle opening 21, and then supplies the ink from an external drive circuit (not shown). In accordance with the recording signal, a voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 to bend and deform the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70. As a result, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzle openings 21.
[0043]
Hereinafter, the manufacturing process of such an ink jet recording head will be described with reference to FIGS. 3 and 4 are cross-sectional views of the pressure generation chamber 12 in the width direction.
[0044]
First, as shown in FIG. 3A, an elastic film 50 made of silicon dioxide is formed by thermally oxidizing a silicon single crystal substrate wafer to be the flow path forming substrate 10 in a diffusion furnace at about 1100 ° C.
[0045]
Next, as shown in FIG. 3B, the lower electrode film 60 is formed over the entire surface of the flow path forming substrate 10 on the pressure generating chamber 12 side by sputtering and patterned into a predetermined shape. As a material of the lower electrode film 60, platinum, iridium or the like is suitable. This is because a piezoelectric layer 70 described later formed by sputtering or sol-gel method needs to be crystallized by firing at a temperature of about 600 to 1000 ° C. in an air atmosphere or an oxygen atmosphere after the film formation. Because. That is, the material of the lower electrode film 60 must be able to maintain conductivity at such a high temperature and in an oxidizing atmosphere, particularly when lead zirconate titanate (PZT) is used as the piezoelectric layer 70. It is desirable that the conductivity change due to diffusion of lead oxide is small, and platinum and iridium are preferable for these reasons.
[0046]
Next, as illustrated in FIG. 3C, the piezoelectric layer 300 and the upper electrode film 80 are sequentially stacked, and only the piezoelectric layer 70 and the upper electrode film 80 are etched to pattern the piezoelectric element 300. .
[0047]
For example, in this embodiment, the piezoelectric layer 70 is formed by applying and drying a so-called sol in which a metal organic material is dissolved and dispersed in a catalyst, gelling, and firing at a high temperature to form the piezoelectric layer 70 made of a metal oxide. It was formed using the so-called sol-gel method. As a material of the piezoelectric layer 70, a PZT material is suitable when used for an ink jet recording head. The method for forming the piezoelectric layer 70 is not particularly limited. For example, the piezoelectric layer 70 may be formed by a spin coating method such as a sputtering method or a MOD method (organic metal thermal coating decomposition method).
[0048]
Alternatively, a method may be used in which a lead zirconate titanate precursor film is formed by a sol-gel method, a sputtering method, a MOD method, or the like, and then crystallized at a low temperature by a high pressure treatment method in an alkaline aqueous solution.
[0049]
Further, the upper electrode film 80 may be any material having high conductivity, and many metals such as aluminum, gold, nickel, and platinum, conductive oxides, and the like can be used. In this embodiment, the platinum film is formed by sputtering.
[0050]
Next, as shown in FIG. 3D, the lead electrode 90 is formed over the entire surface of the flow path forming substrate 10 and patterned for each piezoelectric element 300.
[0051]
The above is the film forming process. After the film formation is performed in this manner, as shown in FIG. 4A, the flow path forming substrate 10 made of the above-described silicon single crystal substrate by the alkaline solution is anisotropically etched, thereby generating the pressure generating chamber 12. Etc. Moreover, in this embodiment, the recessed part 15 which comprises the stress relaxation part 16 is formed in the flow-path formation board | substrate 10 simultaneously.
[0052]
Next, as shown in FIG. 4B, the reservoir forming substrate 30 is joined to the piezoelectric element 300 side of the flow path forming substrate 10, and then the pressure of the flow path forming substrate 10 as shown in FIG. 4C. The nozzle plate 20 is bonded to the surface where the generation chamber 12 opens.
[0053]
Here, as described above, the nozzle plate 20 is bonded to the flow path forming substrate 10 with a thermosetting adhesive. For this reason, each substrate such as the flow path forming substrate 10, the reservoir forming substrate 30, and the nozzle plate 20 expands due to the heat of adhesion, and warpage occurs due to the difference in thermal expansion coefficient of each substrate. There is a risk that the substrate 10 or the like may crack.
[0054]
That is, the flow path forming substrate 10 has a relatively low rigidity in the region where the pressure generation chamber 12 is provided, and its peripheral edge portion has a higher rigidity than the region where the pressure generation chamber 12 is provided. Accordingly, the regions on both outer sides of the row of the pressure generating chambers 12 serve as a boundary between a region having high rigidity and a region having low rigidity, and stress due to warp concentrates on the boundary portion, whereby pressure generation is caused in the flow path forming substrate 10. There is a possibility that breakage such as cracks may occur along the side surface of the chamber 12.
[0055]
However, in the present invention, as described above, since the stress relaxation portions 16 including the plurality of concave portions 15 are provided on both outer sides of the row of pressure generation chambers of the flow path forming substrate 10, the stress due to the warp generated in each substrate is provided. Are not concentrated in part, and breakage such as cracks can be prevented from occurring in the flow path forming substrate 10.
[0056]
Further, in the present embodiment, the rigidity of the flow path forming substrate 10 is gradually increased by gradually reducing the width of each recess 15 toward the end of the flow path forming substrate 10. Therefore, stress concentration on a part of the flow path forming substrate 10 can be reliably eliminated.
[0057]
After that, the connection wiring is connected to the lead electrode 90 by wire bonding. At this time, each substrate is heated at, for example, 100 ° C. to 120 ° C. As described above, the stress relaxation portion is formed on the flow path forming substrate 10. By providing 16, it is possible to prevent the occurrence of cracks and the like due to warpage of the flow path forming substrate 10.
[0058]
Furthermore, by providing the stress relaxation portion 16 on the flow path forming substrate 10, the rigidity of the flow path forming substrate becomes substantially uniform as a whole, so that variation in the amount of displacement of the elastic film 50 can be suppressed, and the ink ejection characteristics. Can be improved.
[0059]
(Embodiment 2)
FIG. 5 is a plan view illustrating a main part of the ink jet recording head according to the second embodiment.
[0060]
As shown in FIGS. 5A and 5B, in the present embodiment, the stress relaxation portion 16A composed of a plurality of recesses 15A is a region along the end of the communication portion 14 constituting a part of the reservoir (see FIG. 5). (In the vicinity of the middle BB ′ line) is provided inside or outside. Further, the respective recesses 15 </ b> A constituting the stress relaxation portion 16 </ b> A are formed with the same width and with a width narrower than the width of the pressure generation chamber 12.
[0061]
As described above, by providing the stress relaxation portion in the flow path forming substrate, the stress due to the warp generated in each substrate does not concentrate on a part as in the first embodiment, and the flow path forming substrate 10 is cracked. Can be prevented from occurring.
[0062]
Further, if the recess 15A is provided in a region along the end portion of the communication portion 14, the rigidity of this region is remarkably lowered, and stress due to the warp of the substrate is concentrated, so that cracking is likely to occur. However, in the present embodiment, since the recess 15A is not provided in the region along the end of the communication portion 14 and is provided inside or outside the region, the flow path forming substrate 10 is not cracked. It can prevent more reliably.
[0063]
Furthermore, the width of the recess 15A constituting the stress relaxation portion 16A is not particularly limited, but it is preferable to form the recess 15A with a width narrower than that of the pressure generation chamber 12 as in this embodiment. Thereby, it is possible to prevent the rigidity of the flow path forming substrate 10 from being lowered more than necessary.
[0064]
In the present embodiment, the widths of the recesses 15A constituting the stress relaxation portion 16A are set to be substantially the same. However, the present invention is not limited to this, and of course, the end of the flow path forming substrate 10 is the same as in the first embodiment. You may make it narrow the width | variety of 15 A of recessed parts in steps toward the side.
[0065]
Further, in the present embodiment, the stress relaxation portion 16A is provided only on one side inside or outside the region along the end portion of the communication portion 14, but of course, it may be provided on both sides.
[0066]
(Other embodiments)
While the embodiments of the present invention have been described above, the basic configuration of the ink jet recording head is not limited to that described above.
[0067]
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, and 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.
[0068]
In addition, the ink jet recording head of each of these embodiments 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. 6 is a schematic view showing an example of the ink jet recording apparatus.
[0069]
As shown in FIG. 6, 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.
[0070]
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 on the platen 8. It is like that.
[0071]
【The invention's effect】
As described above, in the present invention, the flow path forming substrate is provided with the stress relaxation portions whose rigidity has been reduced by forming a plurality of recesses, and the flow paths are formed by changing the widths of these recesses stepwise. Since the rigidity of the forming substrate is changed, it is possible to effectively suppress the stress due to warpage to be concentrated on a part of the flow path forming substrate, and to prevent the flow forming substrate from being cracked. Can do. In addition, since the rigidity of the flow path forming substrate is substantially uniform, variation in the amount of displacement of the vibration plate provided on the flow path forming substrate is suppressed, and the ink ejection characteristics can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an ink jet recording head according to a first embodiment of the invention.
2A and 2B are a plan view and a cross-sectional view illustrating the ink jet recording head according to the first embodiment of the invention.
FIG. 3 is a cross-sectional view showing a manufacturing process of the ink jet recording head according to the first embodiment of the invention.
FIG. 4 is a cross-sectional view showing a manufacturing process of the ink jet recording head according to the first embodiment of the invention.
FIG. 5 is a plan view showing an ink jet recording head according to a second embodiment of the invention.
FIG. 6 is a schematic view of an ink jet 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 13 Ink supply path 14 Communication part 15, 15A Concave part 16, 16A Stress relaxation part 20 Nozzle plate 21 Nozzle opening 30 Reservoir formation board 31 Reservoir part 32 Piezoelectric element holding part 40 Compliance board 50 Elastic film 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 100 Reservoir 300 Piezoelectric element

Claims (5)

A flow path forming substrate in which a pressure generation chamber communicating with the nozzle opening is defined, and a pressure plate formed in a region facing the pressure generation chamber via a diaphragm constituting a part of the pressure generation chamber. In an ink jet recording head comprising a piezoelectric element that causes a pressure change in
At both ends in the column direction of the pressure generating chamber of the flow path forming substrate, a stress relaxation portion having a reduced rigidity by forming a plurality of recesses having a width narrower than the pressure generating chamber is provided, and A recess is formed by etching simultaneously with the pressure generating chamber, and the width of the recess is changed stepwise so as to become narrower toward the end of the flow path forming substrate, thereby changing the rigidity of the flow path forming substrate. An ink jet recording head characterized by comprising:   Each flow generation chamber communicates with the flow path forming substrate, and a communication portion constituting at least a part of a reservoir serving as a common ink chamber of the pressure generation chamber is formed. 2. The ink jet recording head according to claim 1, wherein the ink jet recording head is formed inside or outside a region corresponding to an end portion of the communication portion in the row direction of the generation chamber.   3. The ink jet recording head according to claim 1, wherein a width of each recess constituting the stress relaxation portion is narrower than a width of the pressure generating chamber.   The pressure generation chamber is formed on a silicon single crystal substrate by anisotropic etching, and each layer of the piezoelectric element is formed by film formation and lithography. The ink jet recording head described.   An ink jet recording apparatus comprising the ink jet recording head according to claim 1.

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