JP3667553B2 - Inkjet printer head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an ink jet printer head that records characters and images by causing minute droplets to fly onto a recording medium such as paper.
[0002]
[Prior art]
FIG. 11 is a cross-sectional view schematically showing an example of the configuration of a conventional ink jet printer head that ejects ink droplets using a piezoelectric element, and FIG. 12 is an overview of functions related to ink droplet ejection operations. It is a functional block diagram shown.
[0003]
As shown in FIG. 11, a conventional ink jet printer head 100 includes a plate-like body 102 having a small hole 101 for forming a nozzle, and a frame-like pressure chamber which is superposed and fixed thereon. The component member 103 and the diaphragm 104 that is superposed on the pressure chamber component member 103 are fixed. A plurality of barriers 105 are provided in the inner part of the frame forming the pressure chamber constituting member 103 with a predetermined gap, and divided by the two adjacent barriers 105 and the plate-like body 102 and the diaphragm 104 described above. A plurality of pressure chambers 106 is formed by each formed space.
[0004]
In addition, an ink pool 107 is formed inside the pressure chamber constituting member 103 so as to penetrate the front ends of all the barriers 105, and the ink introduced through the ink tank port 111 of the diaphragm 104 receives the ink. Each pressure chamber 106 is guided through the pool 107 and an ink supply port 112 formed by a gap between the barriers 105 and 105.
[0005]
A plurality of piezoelectric elements 108 are provided on the vibration plate 104 corresponding to each pressure chamber 106, and a plurality of small holes 101 constituting the nozzle are also provided on the plate-like body 102 corresponding to each pressure chamber 106. It is drilled in the place.
[0006]
As shown in FIG. 12, the ink in the ink tank 109 is supplied to the ink pool 107 via the tube 110 and the ink tank port 111. A drive signal for driving the inkjet printer head 100 is generated by the printer main body 113, passes through a flexible printing cable (hereinafter simply referred to as FPC) 114, and reaches a circuit board 115 for a drive circuit. The piezoelectric element 108 is applied to the piezoelectric element 108 through the vibration, and the piezoelectric element 108 receiving the signal vibrates to deform the diaphragm 104 of the pressure chamber 106. As a result, the volume of the pressure chamber 106 is reduced and a pressure wave is generated. By this pressure wave, ink droplets are ejected from the small hole 101 serving as a nozzle and fly to the paper surface or the like.
[0007]
[Problems to be solved by the invention]
In recent years, in the field of ink jet printers, technical problems such as high printing speed and high image quality printing have become problems. First, as means for realizing high speed, there is an increase in the number of nozzles of the ink jet printer head. In order to achieve high image quality, it is desired to change the size of the ink droplets ejected by changing the electrical signal supplied to the piezoelectric element and to change the size of the dots attached to the paper surface. A high-density ink jet printer head is required to satisfy both of these requirements.
[0008]
However, if the number of nozzles is increased or the function of changing the electrical signal supplied to the piezoelectric element is provided, the number of required drive circuits is also redundant and the wiring capacity increases. For example, as shown in FIG. 12, when the substrate on which the piezoelectric element 108 is mounted and the circuit board 115 for the drive circuit are different, the connection is made through the FPC 116 or the like, but the wiring pitch of the FPC or the like is high. Since there is a limit to density, the number of nozzles and circuits that can be mounted on the ink jet printer head 100 is naturally limited, and a sufficient number of nozzles and circuits necessary for high speed and high image quality are necessarily mounted. It is not always possible.
[0009]
Further, it is possible to consider a means in which connection terminals are provided on different substrates, for example, the circuit substrate 115 for the drive circuit and the substrate on which the piezoelectric element 108 is mounted without using the FPC, and the terminals are brought into contact with each other. However, the problem about the limit of the high density of the wiring pitch between terminals still remains.
[0010]
The driving signal sent from the printer main body 113 to the circuit board 115 has the same problem. As the number of nozzles increases, the number of amplifier circuits on the printer main body 113 side also increases. A cooling device such as a heat sink fin is required, which makes it difficult to realize a small inkjet printer.
[0011]
OBJECT OF THE INVENTION
Therefore, an object of the present invention is to provide an ink jet printer head suitable for high-speed printing and high-quality printing by increasing the wiring and circuit configuration.
[0012]
[Means for Solving the Problems]
According to the present invention, a nozzle and a vibration plate are provided in a pressure chamber for storing ink, and the vibration plate is vibrated by a piezoelectric element driven by an electric signal to eject ink droplets from the nozzle. A print head body comprising a nozzle plate in which a plurality of nozzles are arranged in a matrix, a pressure chamber constituting member that constitutes a pressure chamber corresponding to the plurality of nozzles, and a diaphragm And the piezoelectric element Thin film transistor for supplying electrical signals A circuit was formed and the piezoelectric element was mounted The object is achieved by a structure in which an insulating substrate is integrally arranged in the direction of ink discharge in the nozzle so that the pressure chamber corresponds to the piezoelectric element via the diaphragm. did.
For supplying electrical signals to piezoelectric elements Transistor circuit The thin film Transistor circuit By forming the circuit structure, the circuit configuration can be densified. Also this thin film Transistor circuit By deploying together with piezoelectric elements on an insulating substrate Transistor circuit There is no need for a dedicated board, Transistor circuit The wiring capacity between the two is also reduced.
As a result, it becomes easy to arrange a large number of nozzles at a high density, and a high printing speed and high image quality printing are realized.
[0013]
In addition, when an amplifier circuit that amplifies an electrical signal and transmits it to the piezoelectric element is required, this amplifier circuit is also connected to the thin film. Transistor circuit At the same time, it is arranged integrally on the insulating substrate.
As a result of providing the amplifier circuit on the piezoelectric element side, it is not necessary to provide a large number of amplifier circuits on the printer body side, and no heat sink fins for cooling on the printer body side are required, thereby reducing the size of the entire inkjet printer. .
[0014]
Thin film Transistor circuit The amplifier circuit can be formed of, for example, polycrystalline silicon.
[ 0015 ]
A pressure chamber is integrally provided on the piezoelectric element via the diaphragm. In configuration A plate-like body having small holes is provided on the surface of the pressure chamber opposite to the diaphragm, and nozzles are formed by the small holes, thereby realizing high-density deployment of the nozzles.
[0016]
Furthermore, a thin film is formed on the same surface as the surface on which the piezoelectric element is mounted on the insulating substrate. Transistor circuit The Formation When the pressure chamber and the insulating substrate, that is, the pressure chamber and the thin film Transistor circuit A filler with high thermal conductivity is interposed between the filler and the filler to serve as a spacer between the insulating substrate and the print head body. Transistor circuit By forcibly removing the heat generated from the heat generation, the heat generation problem associated with the higher density of the circuit configuration is solved. Moreover, as a result of the filler acting as a spacer, the separation distance between the insulating substrate and the printer head main body is also kept constant.
[0017]
In addition, a thin film is formed on the insulating substrate so as to overlap with the piezoelectric element on the surface opposite to the surface on which the piezoelectric element is mounted. Transistor circuit The Formation The piezoelectric element and thin film located on the front and back of the insulating substrate. Transistor circuit Are connected by a conductive metal. Thin film using the surface opposite to the surface on which the piezoelectric element is mounted, that is, the back surface of the insulating substrate on which the piezoelectric element is not mounted Transistor circuit By arranging the above, it becomes possible to further reduce the area of the insulating substrate and further to arrange the nozzles at a high density.
[0018]
Thin film on the surface opposite to the surface on which the piezoelectric element is mounted Transistor circuit If the is installed, the surface opposite to the surface on which the piezoelectric element is mounted, that is, the thin film Transistor circuit The Formation Install a heat sink on the surface of the Transistor circuit By forcibly removing the heat generated from the circuit, the heat generation problem associated with higher circuit density is solved.
[ 0019 ]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a perspective view showing a configuration of an inkjet printer head 1 according to a first embodiment to which the present invention is applied, and FIG. 1B is a cross-sectional view showing a main part of the inkjet printer head 1 according to the embodiment in a simplified manner. FIG.
[ 0020 ]
The ink jet printer head 1 of this embodiment is generally constituted by a printer head main body 6, a piezoelectric element 7, and an insulating substrate 8. Further, the printer head main body 6 is constituted by a plate-like body 3 (hereinafter referred to as a nozzle plate) having a small hole 2 serving as a nozzle hole, a pressure chamber constituting member 4 and a diaphragm 5, and vibrates the diaphragm 5. A thin film transistor circuit 9 for transmitting an electric signal for driving to the piezoelectric element 7 is integrally formed on the surface of the insulating substrate 8 on which the piezoelectric element 7 is mounted.
[ 0021 ]
The structure of the pressure chamber constituting member 4 is substantially the same as the pressure chamber constituting member 103 of the conventional example shown in FIG.
That is, in the pressure chamber constituting member 4 of the present embodiment shown in FIG. 1B, a predetermined gap is formed in the thickness direction in the drawing on the inner side portion of the frame forming the pressure chamber constituting member 4 in the prior art of FIG. In the same manner as in the example, a plurality of barriers 105 are integrally provided, and a plurality of pressure chambers 106 are formed by spaces formed by partitioning the two barriers 105 adjacent to each other in the thickness direction of the paper, the nozzle plate 3 and the diaphragm 5. It is configured. The shape of the ink pool 107 is the same as that of the conventional example of FIG. 11, and in the pressure chamber constituting member 4 of this embodiment shown in FIG. An ink pool 107 extending in the thickness direction is formed, and the ink in the ink pool 107 is guided to each pressure chamber 106 through an ink supply port 112 formed by a gap between the barriers 105 adjacent to each other in the paper thickness direction. It is burned.
[ 0022 ]
In FIG. 1A and FIG. 1B, the configuration of the printer head body 6 is described with respect to the minimum structural unit required to form one pressure chamber 106. A large number of these structural units are superposed in the front-rear and left-right directions in FIG. 1A, and in FIG. Each nozzle plate 3 has a large number of small holes 2 formed in a matrix (see FIG. 2C).
[ 0023 ]
As shown in FIGS. 1A and 1B, the printer head main body 6 has several (three in the embodiment) rigidity for forming the nozzle plate 3, the pressure chamber constituting member 4, and the diaphragm 5. It has a laminated structure in which plates are superposed and bonded, and the small holes 2 in the nozzle plate 3, the gap (the pressure chamber 106) between the barriers 105, 105 in the pressure chamber constituent member 4, the ink pool 107, etc. are stamped by press Etc.
[ 0024 ]
The thin film transistor circuit 9 may be made of low-temperature process polycrystalline silicon that can use an inexpensive insulating substrate, or may use high-temperature process polycrystalline silicon or other thin film transistors. The vibration plate 5 also serves as a common electrode for the piezoelectric element 7 and uses a Ni plate or other conductive metal plate. As the material of the piezoelectric element 7, a material made of lead zirconate titanate ceramics or a general ferroelectric is used.
[ 0025 ]
Next, a method for manufacturing the ink jet printer head 1 of the first embodiment will be briefly described. FIG. 2 is a diagram for explaining a manufacturing process according to the first embodiment of the present invention. First, as shown in FIG. 2A, a thin film transistor circuit 9 is formed on an insulating substrate 8 by a low pressure CVD method or the like.
[ 0026 ]
Next, as shown in FIG. 2B, the piezoelectric element 7 is mounted on the insulating substrate 8 at a position adjacent to the thin film transistor circuit 8. At this time, spherical solder is arranged between the piezoelectric element 7 and the insulating substrate 8, and the already formed thin film transistor circuit 9 and the piezoelectric element 7 are electrically connected by reflow. After the connection, alignment is performed by polishing the end face of the piezoelectric element 7. Then, each end of the polished piezoelectric element 7 is diced to individualize each piezoelectric element 7 corresponding to each pressure chamber 106 of the minimum structural unit described above.
[ 0027 ]
Thereafter, as shown in FIG. 2C, the printer head body 6 including the diaphragm 5, the pressure chamber constituting member 4, and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0028 ]
Next, the operation of the ink jet printer head 1 formed by this manufacturing method will be described with reference to FIG. Ink is supplied from the printer main body via a tube, and is guided to the pressure chamber 106 via the ink pool 107 and the ink supply port 112. The electrical signal is supplied from the printer main body to the thin film transistor circuit 9 on the insulating substrate 8 through the FPC (not shown) and applied to the piezoelectric element 7. In addition, each piezoelectric element 7 individualized corresponding to the minimum structural unit by dicing functions independently of each other. In response to this signal, the piezoelectric element 7 vibrates and deforms the diaphragm 5 to generate a pressure wave in the pressure chamber 106. Ink droplets are ejected from the small holes 2 serving as nozzle holes by this pressure wave.
[ 0029 ]
FIG. 3A is a perspective view showing the configuration of the ink jet printer head 11 according to the second embodiment of the present invention, and FIG. 3B is a cross-sectional view schematically showing the main part of the ink jet printer head 11 according to the embodiment. It is.
[ 0030 ]
The ink jet printer head 11 of this embodiment is different from the first embodiment described above in that it includes a filler 10 installed for the purpose of conducting and eliminating heat generated from the thin film transistor circuit 9, but other parts. Since the configuration is the same as that of the first embodiment, the same components as those used in the description of FIGS. 1A and 1B are denoted by the same reference numerals, and description thereof is omitted. To do. Note that the filler 10 of this embodiment also has a function as a spacer for maintaining a constant distance between the insulating substrate 8 and the vibration plate 5 of the printer head body 6.
[ 0031 ]
Next, a method for manufacturing the ink jet printer head 11 according to the second embodiment of the present invention will be briefly described. FIG. 4 is a diagram for explaining a manufacturing method according to the second embodiment of the present invention. First, as shown in FIG. 4A, a thin film transistor circuit 9 is formed on an insulating substrate 8 by a low pressure CVD method or the like. Next, as shown in FIG. 4B, the piezoelectric element 7 is mounted on the insulating substrate 8 at a position adjacent to the thin film transistor circuit 9. Similarly to the above, spherical solder is arranged between the piezoelectric element 7 and the insulating substrate 8, and the already formed thin film transistor circuit 9 and the piezoelectric element 7 are electrically connected by reflow. After the connection, alignment is performed by polishing the end face of the piezoelectric element 7. Then, by dicing the polished end face of the piezoelectric element 7, each piezoelectric element 7 which is the minimum structural unit is individualized as described above.
[ 0032 ]
Thereafter, as shown in FIG. 4C, the filler 10 is mounted on the portion covering the thin film transistor circuit 9. Regarding the material of the filler 10, a metal having good thermal conductivity such as aluminum is used. Finally, the printer head main body 6 including the vibration plate 5, the pressure chamber constituting member 4 and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0033 ]
The operation of the inkjet printer head 11 manufactured by this manufacturing method is the same as that of the first embodiment described above. Therefore, the thin film transistor circuit 9 used in this embodiment may be made of low-temperature process polycrystalline silicon using an inexpensive insulating substrate, as in the case of the first embodiment described above, Crystalline silicon or other thin film transistors may be used.
[ 0034 ]
According to this embodiment, the heat generated in the thin film transistor circuit 9 during the operation of the inkjet printer head 11 is absorbed by the filler 10 and released into the atmosphere, so that the temperature rise of the circuit caused by the increase in density is suppressed. be able to.
[ 0035 ]
FIG. 5A is a perspective view showing a configuration of an ink jet printer head 12 according to a third embodiment of the present invention, and FIG. 5B is a cross-sectional view showing a main part of the ink jet printer head 12 according to the embodiment in a simplified manner. It is.
[ 0036 ]
The inkjet printer head 12 of this embodiment is different from the first embodiment described above in that the amplifier circuit 13 is integrally formed with the thin film transistor circuit 9, but the configuration of the other parts is the first embodiment described above. Therefore, the same components as those used in the description of FIGS. 1A and 1B are denoted by the same reference numerals, and description thereof is omitted.
[ 0037 ]
Similarly to the thin film transistor 9, the amplifier circuit 13 may be made of low-temperature process polycrystalline silicon that can use an inexpensive insulating substrate, or high-temperature process polycrystalline silicon or another thin film transistor.
[ 0038 ]
Since the amplifier circuit 13 is formed together with the thin film transistor 9, higher circuit density can be achieved than in the first embodiment.
[ 0039 ]
Next, a method for manufacturing the inkjet printer head 12 according to the third embodiment of the present invention will be briefly described. FIG. 6 is a diagram for explaining a manufacturing process according to the third embodiment of the present invention. First, the thin film transistor circuit 9 and the amplifier circuit 13 are formed on the insulating substrate 8 as shown in FIG.
[ 0040 ]
Next, as shown in FIG. 6B, the piezoelectric element 7 is mounted on the insulating substrate 8 at a position adjacent to the thin film transistor circuit 9 and the amplifier circuit 13. At this time, spherical solder is arranged between the piezoelectric element 7 and the insulating substrate 8, and the thin film transistor circuit 9 and the amplifier circuit 13 already formed are electrically connected by reflow. After the connection, alignment is performed by polishing the end face of the piezoelectric element 7. Then, each end of the polished piezoelectric element 7 is diced to individualize each piezoelectric element 7 which is the minimum constituent unit.
[ 0041 ]
Then, as shown in FIG. 6C, the printer head body 6 including the diaphragm 5, the pressure chamber constituent member 4, and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0042 ]
Next, the operation of the ink jet printer head 12 formed by this manufacturing method will be described with reference to FIG. Ink is supplied from the printer main body via a tube, filled in the ink pool 107, and guided to the pressure chamber 106 via the ink supply port 112. The electrical signal is supplied from the printer main body to the thin film transistor circuit 9 on the insulating substrate 8 through the FPC (not shown), amplified by the amplifier circuit 13, and applied to the piezoelectric element 7. In response to this signal, the piezoelectric element 7 vibrates and deforms the diaphragm 5 to generate a pressure wave in the pressure chamber 106. Ink droplets are ejected from the small holes 2 serving as nozzle holes by this pressure wave.
[ 0043 ]
FIG. 7A is a perspective view showing a configuration of an inkjet printer head 14 according to a fourth embodiment of the present invention, and FIG. 7B is a cross-sectional view showing a simplified main portion of the inkjet printer head 14 according to the embodiment. It is.
[ 0044 ]
The inkjet printer head 14 of this embodiment is different from the third embodiment described above in that a filler 10 that conducts and eliminates heat generated from the thin film transistor circuit 9 and the amplifier circuit 13 is installed. Since the configuration of the portion is the same as that of the third embodiment described above, the same reference numerals as those used in the description of FIGS. 5A and 5B are attached to the overlapping configuration portions. Description is omitted.
[ 0045 ]
Next, a manufacturing method according to the fourth embodiment of the present invention will be briefly described. FIG. 8 is a diagram for briefly explaining the manufacturing process of the fourth embodiment of the present invention. First, as shown in FIG. 8A, the thin film transistor circuit 9 and the amplifier circuit 13 are formed on the insulating substrate 8.
[ 0046 ]
Next, as shown in FIG. 8B, the piezoelectric element 7 is mounted on the insulating substrate 8 at a position adjacent to the thin film transistor circuit 9 and the amplifier circuit 13. At this time, spherical solder is arranged between the piezoelectric element 7 and the insulating substrate 8, and the thin film transistor circuit 9 and the amplifier circuit 13 already formed and the piezoelectric element 7 are electrically connected by reflow. After the connection, alignment is performed by polishing the end face of the piezoelectric element 7. Then, each end of the polished piezoelectric element 7 is diced to individualize each piezoelectric element 7 corresponding to the above-described minimum structural unit.
[ 0047 ]
Thereafter, as shown in FIG. 8C, the filler 10 is mounted on the portion covering the thin film transistor circuit 9 and the amplifier 13. As for the material of the filler 10, a metal having good thermal conductivity such as aluminum is used as in the case of the second embodiment described above. Finally, the printer head main body 6 including the vibration plate 5, the pressure chamber constituting member 4 and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0048 ]
The operation of the inkjet printer head 14 formed by this manufacturing method is the same as that of the third embodiment described above, and the effect of suppressing the temperature rise of the circuit is the same as that of the second embodiment described above. It is. The thin film transistor circuit 9 and the amplifier circuit 13 used in the present embodiment may be made of low-temperature process polycrystalline silicon using an inexpensive insulating substrate, as in the above-described embodiments, or a high-temperature process polycrystal. Silicon or other thin film transistors may be used.
[ 0049 ]
FIG. 9 is a cross-sectional view schematically showing the main part of the configuration of the inkjet printer head 15 according to the fifth embodiment of the present invention. In the ink jet printer head 15 of the present embodiment, the thin film transistor circuit 9 and the amplifier and buffer circuit 17 are formed on the surface of the insulating substrate 8 opposite to the piezoelectric element 7, and the electrical connection 16 made of conductive metal is formed on the end surface of the insulating substrate 8. The thin film transistor circuit 9 and the amplifier / buffer circuit 17 are electrically connected to the piezoelectric element 7, and a heat radiating plate 18 is installed on the thin film transistor circuit 9, the amplifier and buffer circuit 17.
[ 0050 ]
Silver paste, silver palladium paste, or other conductive metal is used as the material of the electrical connection 16, and a metal having good thermal conductivity such as aluminum is used as the material of the heat sink 18. Since the thin film transistor circuit 9 and the amplifier and buffer circuit 17 are formed on the back surface of the insulating substrate 8, they are the same by avoiding the installation surface of the piezoelectric element 7 as in the case where these are formed on the surface of the insulating substrate 8. It is not necessary to arrange on a plane, and the mounting area of the insulating substrate 8 itself can be reduced. In addition, since heat generated from the thin film transistor circuit 9 and the amplifier and buffer circuit 17 can be forcibly removed by the heat radiating plate 18, more stable operation can be achieved.
[ 0051 ]
Next, a manufacturing method according to the fifth embodiment of the present invention will be described. First, the thin film transistor circuit 9 and the amplifier and buffer circuit 17 are formed on the back surface of the insulating substrate 8. Next, a heat radiating plate 18 is mounted on a portion of the insulating substrate 8 that covers the thin film transistor circuit 9 and the amplifier and buffer circuit 17. Then, the piezoelectric element 7 is mounted on the surface of the insulating substrate 8 opposite to the thin film transistor circuit 9 and the amplifier and buffer circuit 17, that is, the front surface of the insulating substrate 8. Thereafter, the alignment is performed by polishing the end face of the piezoelectric element 7. Then, each end of the polished piezoelectric element 7 is diced to individualize each piezoelectric element 7 corresponding to the above-described minimum structural unit.
[ 0052 ]
The electrical connection between the thin film transistor circuit 9 on the back side, the amplifier / buffer circuit 17 and the piezoelectric element 7 on the front side is achieved, for example, by means such as spraying silver paste on the side surface of the insulating substrate 8. Finally, the printer head main body 6 including the vibration plate 5, the pressure chamber constituting member 4 and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0053 ]
Next, the operation of the inkjet printer head 15 formed by this manufacturing method will be described with reference to FIG. Ink is supplied from the printer main body via a tube, and is filled in the ink pool 107. The electrical signal is supplied from the printer main body to the thin film transistor circuit 9 on the insulating substrate 8 through the FPC (not shown), and is amplified by the amplifier of the amplifier and the buffer circuit 13. Then, it is applied to the piezoelectric element 7 on the upper surface side through the electrical connection 16. In response to this signal, the piezoelectric element 7 vibrates and deforms the diaphragm 5 to generate a pressure wave in the pressure chamber 12. Ink droplets are ejected from the small holes 2 serving as nozzle holes by this pressure wave.
[ 0054 ]
The thin film transistor circuit 9 and the amplifier and buffer circuit 17 used in the fifth embodiment of the present invention are made of polycrystalline silicon of a low temperature process using an inexpensive insulating substrate, as in the embodiments described so far. Alternatively, high-temperature process polycrystalline silicon or other thin film transistors may be used.
[ 0055 ]
The heat generated in the thin film transistor circuit 9 and the amplifier and buffer circuit 17 during the operation of the ink jet printer head 15 is absorbed by the heat radiating plate 18 and released into the atmosphere, thereby suppressing the temperature rise of the circuit caused by the increase in density. can do.
[ 0056 ]
FIG. 10 is a cross-sectional view schematically showing the main part of an ink jet printer head 19 according to a sixth embodiment of the present invention.
[ 0057 ]
In the ink jet printer head 19 of this embodiment, a protective film 20 is further formed on the thin film transistor circuit 9 and the amplifier circuit 13 formed integrally on the surface of the insulating substrate 8, and the piezoelectric element 7 is mounted on the protective film 20. ing. The electrical connection between the thin film transistor circuit 9 and the amplifier circuit 13 and the piezoelectric element 7 is achieved, for example, by forming the contact 20 with aluminum or a conductive metal through the protective film 20 by sputtering or the like. The As the material of the protective film 20, an organic thin film is used.
[ 0058 ]
Next, a manufacturing method according to the sixth embodiment of the present invention will be briefly described. First, the thin film transistor circuit 9, the amplifier circuit 13, and the protective film 20 are formed on the insulating substrate 8. Then, a contact hole is opened in the protective film 20, and the contact 21 is formed by sputtering using aluminum or a conductive metal. Next, the piezoelectric element 7 is mounted in accordance with the contact 21 on the protective film 20. At this time, spherical solder is arranged on the contact surface between the piezoelectric element 7 and the contact 21, and the thin film transistor circuit 9 and the amplifier circuit 13 and the piezoelectric element 7 which are already formed are electrically connected by reflow. Thereafter, alignment is performed by polishing the end face of the piezoelectric element 7, and further, the piezoelectric element 7 is individualized by dicing the end face of the polished piezoelectric element 7. Finally, the diaphragm 5, the pressure chamber constituent member A printer head main body 6 composed of 4 and the nozzle plate 3 is mounted on the piezoelectric element 7.
[ 0059 ]
Next, the operation of the ink jet printer head 19 formed by this manufacturing method will be described with reference to FIG. Ink is supplied from the printer main body through a tube, and is filled in the ink pool 107. The electrical signal is supplied from the printer main body to the thin film transistor circuit 9 on the insulating substrate 8 via the FPC (not shown), amplified by the amplifier circuit 13, and then applied to the piezoelectric element 7 via the contact 21. In response to this signal, the piezoelectric element 7 vibrates and deforms the diaphragm 5 to generate a pressure wave in the pressure chamber 12. Ink droplets are ejected from the small holes 2 serving as nozzle holes by this pressure wave.
[ 0060 ]
The thin film transistor circuit 9 and the amplifier circuit 13 used in the sixth embodiment of the present invention may be made of low-temperature process polycrystalline silicon using an inexpensive insulating substrate, as in the above-described embodiments. High temperature process polycrystalline silicon or other thin film transistors may also be used.
[ 0061 ]
【The invention's effect】
The inkjet printer head of the present invention forms a drive circuit such as a piezoelectric element or a transistor on the same insulating substrate. And superimposing in the direction of ink ejection at the nozzle. Has achieved high-density mounting of nozzles and circuits. In a matrix It becomes easy to deploy with high density, and high-speed printing and high-quality printing are realized.
[Brief description of the drawings]
FIG. 1A is a perspective view showing a configuration of a first embodiment to which the present invention is applied, and FIG. 1B is a cross-sectional view showing a main part of the embodiment in a simplified manner.
FIG. 2 is a diagram illustrating the manufacturing process of the embodiment in the order of FIG. 2A, FIG. 2B, and FIG. 2C;
FIG. 3A is a perspective view showing a configuration of a second embodiment to which the present invention is applied, and FIG. 3B is a cross-sectional view showing a simplified main portion of the embodiment.
4 is a diagram for explaining the manufacturing process of the embodiment in the order of FIG. 4A, FIG. 4B, and FIG. 4C;
FIG. 5A is a perspective view showing a configuration of a third embodiment to which the present invention is applied, and FIG. 5B is a cross-sectional view showing a simplified main portion of the embodiment.
6 is a diagram for explaining the manufacturing process of the embodiment in the order of FIG. 6A, FIG. 6B, and FIG. 6C;
FIG. 7A is a perspective view showing a configuration of a fourth embodiment to which the present invention is applied, and FIG. 7B is a cross-sectional view showing a simplified main portion of the embodiment.
FIG. 8 is a diagram for explaining the manufacturing process of the embodiment in the order of FIG. 8A, FIG. 8B, and FIG. 8C;
FIG. 9 is a cross-sectional view schematically showing a main part of a fifth embodiment to which the present invention is applied.
FIG. 10 is a simplified cross-sectional view showing a main part of a sixth embodiment to which the present invention is applied.
FIG. 11 is a cross-sectional view schematically showing an example of the configuration of a conventional inkjet printer head that ejects ink droplets using a piezoelectric element.
FIG. 12 is a functional block diagram showing an outline of functions related to an ink droplet ejection operation of a conventional inkjet printer head.
[Explanation of symbols]
1 Inkjet printer head
2 Small holes (nozzle holes)
3 Plate (nozzle plate)
4 Pressure chamber components
5 Diaphragm
6 Printer head body
7 Piezoelectric elements
8 Insulating substrate
9 Thin film transistor circuit
10 Filler
11 Inkjet printer head
12 Inkjet printer head
13 Amplifier circuit
14 Inkjet printer head
15 Inkjet printer head
16 Electrical connection
17 Amplifier and buffer circuit
18 Heat sink
19 Inkjet printer head
20 Protective film
21 Contact
105 Barrier
106 Pressure chamber
107 Ink pool
112 Ink supply port

Claims (7)

An inkjet printer head configured to provide a nozzle and a vibration plate in a pressure chamber for storing ink, and to vibrate the vibration plate by a piezoelectric element driven by an electric signal to discharge ink droplets from the nozzle,
Supply and a nozzle plate in which a plurality of nozzles are arranged in a matrix, and a print head body comprising a pressure chamber constituting member and the diaphragm constituting the pressure chambers corresponding to said plurality of nozzles, the electrical signal to said piezoelectric element And an insulating substrate on which the piezoelectric element is mounted and integrated with the pressure chamber on the piezoelectric element via the diaphragm in the direction of ink discharge in the nozzle. An inkjet printer head, wherein the inkjet printer head is provided. 2. The ink jet printer head according to claim 1, wherein the thin film transistor circuit is made of polycrystalline silicon. The amplifier circuit which amplifies the said electric signal and transmits to the said piezoelectric element is provided, This amplifier circuit is integrally formed on the said insulated substrate with the said thin-film transistor circuit , The Claim 1 or 2 characterized by the above-mentioned. Inkjet printer head.   4. The ink jet printer head according to claim 3, wherein the amplifier circuit is made of polycrystalline silicon. Forming the thin film transistor circuit on the same surface as the surface on which the piezoelectric element is mounted in the insulating substrate, and interposing a filler having high thermal conductivity in the space between the pressure chamber and the insulating substrate; this filler with serve also as a spacer between the insulating substrate and the printhead body, according to claim 1, characterized in that so as to forcibly removed the heat generated from the thin film transistor circuit via the filler The inkjet printer head as described in any one of thru | or 4 . The thin film transistor circuit is formed on the surface of the insulating substrate opposite to the surface on which the piezoelectric element is mounted so as to overlap with the piezoelectric element, and the thin film transistor circuit and the piezoelectric element are electrically connected by a conductive metal. inkjet printer head according to any one of claims 1 to 4, characterized in that connected. 7. The ink jet printer head according to claim 6, wherein a heat radiating plate is installed on the thin film transistor circuit to forcibly exclude heat generated from the thin film transistor.

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