JP4344116B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject liquid droplets from a nozzle opening by pressurizing a liquid supplied to a pressure generating chamber communicating with a nozzle opening that ejects liquid droplets through a piezoelectric element. In particular, the present invention relates to an ink jet recording head and an ink jet recording apparatus that discharge ink droplets.
[0002]
[Prior art]
As the liquid ejecting apparatus, for example, a plurality of pressure generating chambers that generate pressure for ejecting ink droplets by piezoelectric elements or heat generating elements, a common reservoir that supplies ink to each pressure generating chamber, and each pressure generating chamber There is an ink jet recording apparatus that includes an ink jet recording head having a nozzle opening that communicates with the ink jet recording apparatus. The ink jet recording apparatus applies ejection energy to ink in a pressure generating chamber that communicates with a nozzle corresponding to a print signal. Ink droplets are ejected from the nozzle openings.
[0003]
In such an ink jet recording head, as described above, a heating element such as a resistance wire that generates Joule heat by a drive signal is provided in the pressure generation chamber as a pressure generation chamber. There are two types: one that ejects ink droplets, and one that generates a part of the pressure generation chamber with a vibration plate, and the vibration plate is deformed by a piezoelectric element to eject ink droplets from nozzle openings. Is done.
[0004]
In addition, there are two types of piezoelectric vibration type ink jet recording heads: one that uses a piezoelectric actuator in the longitudinal vibration mode that extends and contracts the piezoelectric element in the axial direction and one that uses a piezoelectric actuator in the flexural vibration mode. Has been.
[0005]
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.
[0006]
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.
[0007]
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 JP-A-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.
[0008]
This eliminates the need to affix the piezoelectric element to the diaphragm, so that not only can the piezoelectric element be created by a precise and simple technique called lithography, but also the thickness of the piezoelectric element can be reduced. There is an advantage that high-speed driving is possible.
[0009]
By using a piezoelectric element formed of such a thin film, the printing quality and the printing speed can be improved. In recent years, further improvement in the printing quality and the printing speed is desired.
[0010]
[Problems to be solved by the invention]
Such a request can be met by increasing the number of nozzle openings arranged, but there is a problem that the drive IC for driving the piezoelectric element has to be enlarged with the increase in the number of nozzle openings arranged. .
[0011]
That is, when the drive IC is formed relatively large, there is a problem that the cost is remarkably increased. Further, if the drive IC is to be increased in size, there is a risk of voltage drop and the like, and it is necessary to ensure a relatively large wiring area in order to prevent this. Therefore, there is a problem that the drive IC becomes larger than necessary.
[0012]
Furthermore, it is difficult to form the drive IC with a size greater than a certain length, and there is a possibility that the drive IC cannot fully cope with the increase in the number of nozzles arranged.
[0013]
Such a problem exists not only in an ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject liquid other than ink.
[0014]
In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus that can reduce the size of the head and increase the number of nozzle openings.
[0015]
[Means for Solving the Problems]
A first aspect of the present invention that solves the above problems includes a flow path forming substrate in which a pressure generation chamber communicating with a nozzle opening is defined, a lower electrode provided on the flow path forming substrate via a vibration plate, and a piezoelectric element. A liquid ejecting head including a piezoelectric element including a body layer and an upper electrode includes a bonding substrate bonded to the piezoelectric element side of the flow path forming substrate, and external wiring is connected to the bonding substrate. A wiring pattern is provided, and at least two driving ICs for driving the piezoelectric elements are mounted on the wiring pattern at predetermined intervals along the direction in which the pressure generating chambers are arranged in parallel. A drive voltage supply pad to which a drive voltage distributed to the piezoelectric element is supplied is provided, and a signal input to which a predetermined drive signal is input by connecting an input wiring extending from the wiring pattern is provided. A pad and a signal output pad for outputting a part of the input drive signals that are not easily affected by a voltage drop are disposed, and the signal output pad of one adjacent drive IC and the other drive IC are disposed. The signal input pad is connected to the other drive IC by a connection wiring, and a drive signal that is not easily affected by a voltage drop is supplied to the other drive IC via the connection wiring. A part of the driving signals that are easily affected by the descent are driven by the driving ICs in a direction parallel to the direction in which the pressure generating chambers are juxtaposed via the input wiring connected to the wiring pattern at the gap between the two driving ICs. The liquid jet head is characterized by being input from both ends of the liquid jet head.
[0016]
In the first aspect, a liquid ejecting head in which the number of nozzle openings is increased can be realized relatively easily by arranging a plurality of driving ICs in parallel. In addition, since the space for forming the wiring for supplying the drive signal to be supplied to the drive IC can be reduced, the size of the head can be reduced.
[0017]
According to a second aspect of the present invention, in the first aspect, the drive ICs are arranged in parallel along the longitudinal direction at a predetermined interval, and the signal input pad is disposed in the vicinity of one end of the drive IC in the longitudinal direction. In addition, in the liquid ejecting head, the signal output pad is disposed in the vicinity of the other end portion in the longitudinal direction of the driving IC.
[0018]
In the second aspect, since the drive IC and the connection pattern are connected on the end side in the longitudinal direction of the drive IC, the width of the head can be reduced.
[0019]
According to a third aspect of the present invention, in the second aspect, in the vicinity of the other end portion in the longitudinal direction of the drive IC, at least a part of the drive signals excluding the signal output via the signal output pad corresponds. In the liquid ejecting head, a signal input pad is further provided.
[0020]
In the third aspect, for example, a predetermined drive signal such as a power supply signal for driving the drive IC can be input from both sides in the longitudinal direction of the drive IC. Can be discharged.
[0021]
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 input wiring is connected to the wiring pattern inside a width of the driving IC. .
[0022]
In the fourth aspect, since it is not necessary to secure a space for connecting the wiring pattern and the input wiring outside the driving IC in the width direction, the size of the head, in particular, the width can be reduced.
[0023]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the drive IC is a serial-parallel conversion type driver IC, and is affected by a drive voltage output via the signal output pad. In the liquid ejecting head, the difficult driving signal includes at least a clock signal and a latch signal.
[0024]
In the fifth aspect, the head can be reduced in size without causing a voltage drop or the like.
[0025]
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the drive signal input from the signal input pad via the input wiring includes at least a ground signal and a drive power supply signal. The liquid jet head is characterized by the following.
[0026]
In the sixth aspect, the head can be downsized without causing a voltage drop or the like.
[0027]
According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the pressure generating chamber is formed by anisotropically etching a silicon single crystal substrate, and each layer of the piezoelectric element is formed and lithographically formed. The liquid ejecting head is formed by a method.
[0028]
In the seventh aspect, a large number of liquid jet heads having high-density nozzle openings can be manufactured relatively easily.
[0029]
An eighth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to seventh aspects.
[0030]
In the eighth aspect, it is possible to improve the printing quality and realize a downsized liquid ejecting apparatus.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments.
[0032]
(Embodiment 1)
FIG. 1 is an exploded perspective view illustrating an outline of an ink jet recording head according to Embodiment 1, FIG. 2 is a schematic plan view and a cross-sectional view of FIG. 1, and FIG. 3 illustrates a drive IC and connection wiring. FIG. 4 is a cross-sectional view schematically showing a main part of the ink jet recording head.
[0033]
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 film 50 is formed.
[0034]
In this flow path forming substrate 10, by performing anisotropic etching from the other direction side, two rows of pressure generating chambers 12 partitioned by a plurality of partition walls 11 are arranged in parallel in the width direction. 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, and is communicated with one end portion in the longitudinal direction of each pressure generation chamber 12 via an ink supply path 14. .
[0035]
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.
[0036]
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 14 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 14 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.
[0037]
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 wall 11 between the adjacent pressure generation chambers 12.
[0038]
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, 0.1 to 1 mm and a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], or Made of 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.
[0039]
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.
[0040]
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 constituted 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.
[0041]
Each upper electrode film 80, which is an individual electrode of the piezoelectric element 300, is a region that is drawn from the vicinity of the end of the pressure generation chamber 12 opposite to the ink supply path 14 and faces between the rows of the pressure generation chambers 12. A lead electrode 90 made of, for example, gold (Au) or the like extending to the elastic film 50 is connected.
[0042]
On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a piezoelectric element that has a space that does not hinder the movement of the piezoelectric element 300 in a region facing the piezoelectric element 300 and can seal the space. The sealing substrate 30 having the holding portion 31 is bonded. The sealing substrate 30 is provided with a reservoir portion 32 that constitutes at least a part of the reservoir 100. In the present embodiment, the reservoir portion 32 is formed across the width direction of the pressure generation chamber 12 through the sealing substrate 30 in the thickness direction, and as described above, the communication portion of the flow path forming substrate 10. The reservoir 100 is connected to the pressure generation chamber 12 and serves as a common ink chamber for the pressure generation chambers 12.
[0043]
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. It was formed using a silicon single crystal substrate of the material.
[0044]
Further, a through hole 33 that penetrates the sealing substrate 30 in the thickness direction is provided in a substantially central portion of the sealing substrate 30, that is, in a region facing between the rows of the pressure generation chambers 12. The vicinity of the tip of the lead electrode 90 drawn out from each piezoelectric element 300 is exposed in the through-hole 33 and is connected to a drive IC 110 (to be described later) and a drive wiring 111 made of a bonding wire.
[0045]
In addition, on the sealing substrate 30, a plurality of driving ICs 110 (first driving IC 110 </ b> A, second driving IC 110 </ b> B) are arranged in parallel with the pressure generation chambers 12 in regions corresponding to the rows of the pressure generation chambers 12. It is arranged along the installation direction. For example, in the present embodiment, the first driving IC 110A and the second driving IC 110B are fixed at a predetermined interval along the longitudinal direction in a region of the sealing substrate 30 facing the row of the pressure generation chambers 12. .
[0046]
These drive ICs 110 are connected to a wiring pattern 120 provided on the sealing substrate 30 by an input wiring 115 made of a bonding wire. The wiring pattern 120 is connected to an end portion of the sealing substrate 30 such as an FPC. It is connected to the external wiring 130. A signal supplied from the external wiring 130 is supplied to each driving IC 110 via the wiring pattern 120.
[0047]
Specifically, as shown in FIGS. 3 and 4, the first drive IC 110 </ b> A and the second drive IC 110 </ b> B are arranged in parallel along the longitudinal direction from the external wiring 130 side on the sealing substrate 30. On the first and second drive ICs 110A and 110B, a plurality of drive voltage supply pads 113 to which a drive voltage for driving each piezoelectric element 300 is input are intermittently provided in the longitudinal direction. It has been. Further, each drive voltage supply pad 113 is connected to each other by a connection wiring 114 made of a conductive wire such as a bonding wire. The drive voltage supply pads 113 at both ends arranged side by side are connected to the wiring pattern 120 by input wirings 115 made of conductive wires such as bonding wires.
[0048]
Therefore, the driving voltage input from the external wiring 130 is supplied from both ends in the longitudinal direction via the wiring pattern 120 extending along the longitudinal direction of each driving IC 110. .
[0049]
In addition, in the present embodiment, a plurality of signal input pads 116 to which drive signals that are mainly control system signals are input are arranged near one end in the longitudinal direction of each drive IC 110, in this embodiment, near the end on the external wiring 130 side. It is installed. In addition, a plurality of signal output pads 117 to which a part of the drive signal input via the signal input pad 116 is output are disposed in the vicinity of the other longitudinal end of each drive IC 110. The input wirings 115 extending from the wiring patterns 120 corresponding to the respective driving signals are connected to the respective signal input pads 116 of the first driving IC 110A.
[0050]
Furthermore, in this embodiment, a signal input pad 118 to which a part of the drive signal is input is also provided on the other longitudinal end side of each drive IC 110, and these signal input pads 118 are the first drive IC 110A. And the second driving IC 110B are connected to the wiring pattern 120 by the input wiring 115. That is, a predetermined drive signal is input from both ends in the longitudinal direction of each drive IC 110.
[0051]
On the other hand, a part of the signal input pad 116 of the second drive IC 110B has a wiring pattern in the gap portion between the first drive IC 110A and the second drive IC 110B, as with the signal input pad 118 of the first drive IC 110A. The input wiring 115 drawn from 120 is connected, but the input signal pad 116 corresponding to a predetermined drive signal, that is, the signal input pad 116 (116A corresponding to the signal output pad 117 provided in the first drive IC 110A). ) Is connected to a connection wiring 119 made of a conductive wire such as a bonding wire extending from the signal output pad 117. That is, a part of the drive signal is input to the second drive IC 110B via the first drive IC 110A.
[0052]
Here, the drive signal includes, for example, a power supply signal and a ground signal for driving the drive IC, various control system signals such as a serial signal, a clock signal, and a latch signal. Of the drive signals supplied to the first and second drive ICs 110A and 110B, a drive signal that is easily affected by a voltage drop, such as a power supply signal or a ground signal, is input to the drive IC 110 from the connection wiring 114 to the input wiring. It is desirable to supply via 115.
[0053]
For this reason, in this embodiment, signal input pads corresponding to the power supply signal (VDD), the ground signal (GND), and the like are provided on both sides in the longitudinal direction of the first and second drive ICs.
[0054]
On the other hand, since the clock signal, the latch signal, and the like, which are drive signals of the control system, are less affected by the voltage drop, they may be input to the second drive IC 110B via the first drive IC 110A. Even if the predetermined signal output pad 117 of the first driving IC 110A and the signal input pad 116 of the second driving IC 110B are connected by the connecting wiring 119, the print quality is not deteriorated.
[0055]
For this reason, in the present embodiment, the latch signal (LAT), the clock signal (SCLK), and the like, which are drive signals for the control system, are supplied from the signal output pad 117 of the first drive IC 110A to the second drive via the connection wiring 119. The signal is input to the signal input pad 116 (116A) of the IC 110B. In FIG. 3, the number of signal input pads 116 and the like are partially omitted, which is different from the actual one.
[0056]
The serial signal may also be supplied to the second drive IC 110B via the first drive IC 110A. However, it is necessary to increase the clock signal. Because it leads to up, it is not so preferable.
[0057]
As described above, in the configuration of the present embodiment, the space for drawing out the input wiring 115 from the wiring pattern 120 can be kept small, so that the head can be reduced in size relatively easily. In addition, since a plurality of drive ICs 110 can be easily arranged side by side, a significant increase in cost can be suppressed, and an increase in the number of nozzles, for example, an ink jet recording head having about 360 nozzles per row can be realized. be able to.
[0058]
Furthermore, in this embodiment, the signal input pads 116 and 118 are provided in the vicinity of the longitudinal ends of the first and second drive ICs 110A and 110B, and the input wiring 115 is extended along the longitudinal direction. . That is, the input wiring 115 is connected to the wiring pattern 120 inside the width of the driving IC 110. Thereby, it is not necessary to secure a space for drawing out the input wiring 115 outside the driving IC 110 in the width direction, and the width of the head can be greatly reduced.
[0059]
As shown in FIGS. 1 and 2, a compliance substrate including a sealing film 41 and a fixing plate 42 is further provided on the sealing substrate 30 on which the first and second driving ICs are mounted. 40 is joined. 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.
[0060]
Although not shown, the sealing substrate 30 and the compliance substrate 40 are formed with ink inlets that allow the reservoir 100 to communicate with the outside, and ink is supplied into the reservoir 100 from the ink inlets.
[0061]
In such an ink jet recording head according to the present embodiment, ink connected to an external ink supply unit (not shown) is taken in, filled with ink from the reservoir 100 to the nozzle opening 21, and then driven by the driving ICs 110A and 110B. A drive voltage is applied between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the generation chamber 12 to cause the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 to bend and deform, thereby generating each pressure. The pressure in the chamber 12 increases and ink droplets are ejected from the nozzle openings 21.
[0062]
(Other embodiments)
Although the present invention has been described above, of course, the present invention is not limited to the above-described embodiment.
[0063]
For example, in the above-described embodiment, two drive ICs are provided in a region facing each row of pressure generation chambers, but, of course, three or more drive ICs may be provided in parallel. .
[0064]
Further, for example, in the above-described embodiment, a driving voltage for driving the piezoelectric element 300 is input from both ends in the longitudinal direction of each driving IC 110. Of course, either one end of the driving IC 110 in the longitudinal direction is input. It may be input from only the side.
[0065]
Further, for example, in the above-described embodiment, the thin film type ink jet recording head manufactured by applying the film forming and lithography method is taken as an example, but of course, the present invention is not limited thereto. The present invention can also be applied to a pressure film type ink jet recording head formed by a method such as sticking.
[0066]
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. 5 is a schematic view showing an example of the ink jet recording apparatus.
[0067]
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.
[0068]
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.
[0069]
In the above-described embodiment, an example of an ink jet recording head that prints a predetermined image or character on a print medium has been described as an example of a liquid ejecting head, but the present invention is not limited to this. For example, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used for forming an electrode such as an organic EL display and an FED (surface emitting display), and a bio-organic ejecting head used for manufacturing a biochip The present invention can also be applied to other liquid ejecting heads.
[0070]
【The invention's effect】
As described above, in the present invention, at least two drive ICs are arranged side by side on the bonding substrate, the signal output pad of one drive IC and the signal input pad of the other drive IC are directly connected, and the drive signal Since a part is input to the other drive IC via one drive IC, the space for connecting each drive IC and the wiring pattern can be kept small, and the head can be miniaturized.
[0071]
Also, since a plurality of drive ICs can be arranged side by side to make a substantially long drive IC, an ink jet recording head having a significantly increased number of nozzles per row can be realized relatively easily. This can also reduce the cost.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an outline of 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 an outline of the ink jet recording head according to the first embodiment of the invention.
FIG. 3 is a plan view showing a connection state between the drive IC and the connection wiring according to the first embodiment of the present invention.
FIG. 4 is a cross-sectional view schematically showing a main part of the ink jet recording head according to the first embodiment of the invention.
FIG. 5 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 20 Nozzle plate 21 Nozzle opening 30 Sealing board 31 Piezoelectric element holding | maintenance part 32 Reservoir part 40 Compliance board | substrate 60 Lower electrode film 70 Piezoelectric layer 80 Upper electrode film 90 Lead electrode 100 Reservoir 110A 1st Drive IC
110B second driving IC
111 drive wiring 113 drive voltage supply pad 114 connection wiring 115 input wiring 116, 116A, 118 signal input pad 117 signal output pad 119 connection wiring 120 wiring pattern 130 external wiring 300 piezoelectric element

Claims (8)

A liquid comprising a flow path forming substrate in which a pressure generation chamber communicating with a nozzle opening is defined, and a piezoelectric element including a lower electrode, a piezoelectric layer, and an upper electrode provided on the flow path forming substrate via a vibration plate In the jet head,
A bonding substrate bonded to the piezoelectric element side of the flow path forming substrate is provided, and a wiring pattern to which external wiring is connected is provided on the bonding substrate, and at least two for driving the piezoelectric element Two drive ICs are mounted on the wiring pattern at predetermined intervals along the direction in which the pressure generating chambers are juxtaposed,
These drive ICs are provided with a drive voltage supply pad to which a drive voltage distributed to the piezoelectric element is supplied, and an input wiring extending from the wiring pattern is connected to a predetermined drive signal. And a signal output pad for outputting a part of the input drive signals that are not easily affected by a voltage drop, and a signal output of one adjacent drive IC. The pad and the signal input pad of the other driving IC are connected by a connection wiring,
The other drive IC is supplied with a drive signal that is hardly affected by a voltage drop through the connection wiring, and some of the drive signals that are easily affected by a voltage drop including a serial signal are 2 Input from both ends of the drive IC in a direction parallel to the direction in which the pressure generating chambers are arranged in parallel through the input wiring connected to the wiring pattern at a gap between two drive ICs Liquid jet head.   The drive ICs are arranged in parallel along the longitudinal direction at predetermined intervals, the signal input pad is disposed near one end of the drive IC in the longitudinal direction, and the signal output pad is disposed in the longitudinal direction of the drive IC. The liquid jet head according to claim 1, wherein the liquid jet head is disposed in the vicinity of the other end of the liquid jet head.   The signal input pad corresponding to at least a part of drive signals excluding the signal output via the signal output pad is further provided in the vicinity of the other longitudinal end of the drive IC. 2. A liquid jet head according to 2.   The liquid ejecting head according to claim 1, wherein the input wiring is connected to the wiring pattern inside a width of the driving IC.   The drive IC is a serial-parallel conversion type driver IC, and the drive signal hardly affected by the drive voltage output via the signal output pad includes at least a clock signal and a latch signal. The liquid jet head according to any one of 1 to 4.   The liquid ejecting head according to claim 1, wherein the drive signal input from the signal input pad via the input wiring includes at least a ground signal and a drive power supply signal.   The pressure generation chamber is formed by anisotropically etching a silicon single crystal substrate, and each layer of the piezoelectric element is formed by film formation and lithography. A liquid ejecting head according to claim 1.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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