JP2001171110A - Ink jet head and method of manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head, and a method of manufacture, in which a driving board and a board corresponding to a counter board can be made from one Si board. SOLUTION: The ink jet head comprises a driving board 1 of Si, a polysilicon film 4 formed thereon through an oxide film 2, an opening 4a made in the polysilicon film 4, a driver IC chip 11 arranged on the opening 4a and the polysilicon film 4, a piezoelectric film 6 formed on the bottom of the opening 4a to extend over the polysilicon film 4, and a pressure generating chamber 1b formed in the driving board 1 beneath the piezoelectric film 6 and receiving ink pressurized by the piezoelectric film 6. The opening 4a prevents movement of the piezoelectric film 6 from being blocked at the time of pressurizing ink in the pressure generating chamber 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a head of a piezoelectric type ink jet printer and a method of manufacturing the same.
In particular, the present invention relates to an ink jet head capable of manufacturing a substrate corresponding to a driving substrate and a counter substrate using a single Si substrate, and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a schematic structure of a conventional ink jet head.

This ink jet head has a driving substrate 101 made of Si. This driving substrate 101
Nozzle substrate 1 made of a thin stainless steel plate
03 is arranged. S on the upper surface of the driving substrate 101
An opposing substrate 105 made of i is arranged. A piezoelectric film (PZT) 106 composed of a piezo element or the like is arranged between the lower surface of the counter substrate 105 and the driving substrate 101. An organic film (PPS Fil
m) 107, and the organic film 107
A substrate 109 made of a thin stainless steel plate is arranged on the upper surface of the substrate. A driver IC chip 111 is arranged inside the organic film 107 and the substrate 109 and on the upper surface of the counter substrate 105.

[0004] An ink flow path 105a is provided in the counter substrate 105, and an ink introduction port 109a is formed at one end of the ink flow path 105a. This ink inlet 1
Reference numeral 09a is provided on the substrate 109 and the organic film 107, and is for introducing ink into the ink flow path 105a. One end of an ink supply section 101a is provided in communication with the other end of the ink flow path 105a, and a pressure generating chamber 101b is provided in communication with the other end of the ink supply section 101a. The ink supply unit 101a and the pressure generating chamber 101b are provided on the driving substrate 101.

The piezoelectric film 1 is provided above the pressure generating chamber 101b.
06 is located. Nozzle openings 103a and 103b for discharging ink droplets are formed below the pressure generating chamber 101b, and the nozzle openings 103a and 103b are formed.
Are provided on the nozzle substrate 103.

[0006] Unillustrated electrode layers are formed above and below the piezoelectric film 106. The opposing substrate 105 has a piezoelectric film 106
An upper space 105b is provided. The space 105b is of a size that does not hinder the movement of the piezoelectric film for generating pressure in the pressure generating chamber 101b.

The bonding wire 113 is provided on the electrode layer.
Are electrically connected to each other, and the other end of the bonding wire 113 is electrically connected to the driver IC chip 111. A wiring pattern 115 is formed on the counter substrate 105. This wiring pattern 115
Is electrically connected to one end of a bonding wire 114, and the other end of the bonding wire 114 is electrically connected to the driver IC chip 111.

Next, the operation when printing is actually performed using the above-described ink jet head will be described.

[0009] The ink flow path 10 from the ink introduction port 109a
The ink is introduced into 5a, and the pressure generating chamber 101b is filled with ink via the ink supply unit 101a. Then, the bonding wires 113,
By applying an electric field between the upper and lower electrode layers of the piezoelectric film via 114, the piezoelectric film 106 bends in the direction of arrow 117. The volume of the bent portion reduces the volume of the pressure generating chamber 101b, so that a part of the reduced volume of ink is ejected from the nozzle openings 103a and 103b. Printing is performed using the ink thus ejected.

[0010]

In the above-described conventional ink jet head, the driving substrate 1 made of Si is used.
The structure is such that the opposing substrates 105 made of Si and 01 are separately manufactured and then bonded together. Since two Si substrates are required,
The parts cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an ink jet head capable of manufacturing a substrate corresponding to a driving substrate and a counter substrate using a single Si substrate and a method of manufacturing the same. Is to provide.

[0012]

According to the present invention, there is provided an ink jet head comprising: a driving substrate made of Si; a polysilicon film disposed on the driving substrate via an oxide film;
An opening provided in the polysilicon film; a driver IC chip disposed on the opening and the polysilicon film; and a piezoelectric element disposed on the bottom of the opening and extended on the polysilicon film. A pressure generating chamber formed in the driving substrate and positioned below the piezoelectric film, the pressure generating chamber containing ink pressed by the piezoelectric film; Is to prevent the movement of the piezoelectric film when the ink in the pressure generating chamber is pressurized.

According to the above-described ink jet head, since the polysilicon film is disposed on the driving substrate via the silicon oxide film, two silicon substrates are required to manufacture each of the driving substrate and the opposing substrate. Is different from the conventional inkjet head. That is, the inkjet head has a structure in which a substrate corresponding to a driving substrate and a counter substrate can be manufactured by one silicon substrate.

[0014] The ink jet head according to the present invention preferably further includes a bonding wire for applying a voltage from a driver IC chip to the piezoelectric film.

Further, in the ink jet head according to the present invention, a nozzle substrate disposed below the driving substrate, and a part of the ink formed on the nozzle substrate and pressurized in the pressure generating chamber is discharged. And a nozzle opening.

Further, the ink jet head according to the present invention preferably further includes an ink supply section formed in communication with the pressure generating chamber and supplying ink to the pressure generating chamber.

The ink jet head according to the present invention preferably further includes an ink inlet for introducing ink into the ink supply section.

According to the method of manufacturing an ink jet head of the present invention, a step of forming a silicon oxide film on a silicon substrate, a step of forming a polysilicon film on the silicon oxide film, and a selective etching of the polysilicon film are performed. Forming an opening, forming a piezoelectric film at the bottom of the opening, forming a pressure generating chamber in the silicon substrate and under the piezoelectric film by selective etching, Driver I on the polysilicon film
A step of mounting a C chip, wherein the pressure generating chamber is for receiving ink pressurized by the piezoelectric film, and the opening is configured to pressurize the ink in the pressure generating chamber. It is characterized in that the movement of the piezoelectric film is not hindered.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a schematic configuration of an ink jet head according to an embodiment of the present invention.

This ink jet head has a driving substrate 1 made of Si. A nozzle substrate 3 made of a thin plate made of stainless steel is arranged on the lower surface of the driving substrate 1. A silicon oxide film 2 is formed on the upper surface of the driving substrate 1, and a polysilicon film 4 is formed on the silicon oxide film 2. An organic film (PPS Film) 7 is disposed on the polysilicon film 4, and a substrate 9 made of a stainless steel thin plate is disposed on the upper surface of the organic film 7. Organic film 7 and substrate 9
A driver IC is provided inside the polysilicon film 4 and on the upper surface of the polysilicon film 4.
A chip 11 is arranged. Between the lower surface of the IC chip 11 and the upper surface of the polysilicon film 4, a piezoelectric film (PZT) 6 composed of a piezo element or the like is arranged. By thus mounting the IC chip 11 on the piezoelectric film 6, the piezoelectric film 6 is protected by the IC chip 11.

The thickness and detailed shape of each of the driving substrate 1, the nozzle substrate 3, the organic film 7, and the substrate 9 may be various as long as they can exert mechanical strength and a printing function of an ink jet head. Shapes and the like can be used.

The driving substrate 1 is provided with an ink supply section 1a. An ink inlet 9a is disposed at one end of the ink supply unit 1a.
It is provided on the substrate 9 and the organic film 7. Since the ink introduction port 9a is for introducing the ink into the ink supply section 1a, various shapes and the like can be used as long as the size and shape of the ink introduction port 9a are suitable for introducing the ink. is there.

A pressure generating chamber 1 is provided at the other end of the ink supply section 1a.
b are formed so as to communicate with each other.
The pressure generating chamber 1b is provided on the driving substrate 1.
Since the ink supply unit 1a supplies ink to the pressure generating chamber 1b, various shapes and the like can be used as long as the size and shape of the ink supply unit 1a are suitable for ink supply. .

Nozzle openings 3a and 3b for discharging ink droplets are formed below the pressure generating chamber 1b, and the nozzle openings 3a and 3b are provided on the nozzle substrate 3. Since the pressure generating chamber 1b generates pressure by the piezoelectric film 6 in the ink supplied therein, the size and shape of the pressure generating chamber 1b may be various shapes and the like as long as they are suitable for pressure generation. Can be used. Also, various shapes and the like can be used for the nozzle openings 3a and 3b.

A piezoelectric film 6 is located above the pressure generating chamber 1b, and the piezoelectric film 6 extends over the polysilicon film 4. Electrode layers (not shown) are formed above and below the piezoelectric film 6. A space 4a located on the piezoelectric film 6 is provided below the driver IC chip 11, and the space 4a is an opening formed in the polysilicon film 4. The space 4a is of a size that does not hinder the movement of the piezoelectric film for generating pressure in the pressure generating chamber 1b.

One end of a bonding wire 13 is electrically connected to the electrode layer, and the other end of the bonding wire 13 is electrically connected to a pad on the upper surface of the driver IC chip 11.

Next, a method of manufacturing the ink jet head shown in FIG. 1 will be described.

FIGS. 2A to 2C are cross-sectional views showing a method of manufacturing the driving substrate and the polysilicon film shown in FIG.

First, as shown in FIG. 2A, a silicon substrate 1 is prepared, and a silicon oxide film 2 is formed on the silicon substrate 1 by a thermal oxidation method or a CVD (Chemical Vapor Deposition) method. Next, a polysilicon film 4 is deposited on the silicon oxide film 2 by a CVD method.

Thereafter, as shown in FIG. 2B, a resist film (not shown) is applied on the polysilicon film 4, and the resist film is exposed and developed, so that the polysilicon film 4 is exposed. A resist pattern is formed. Next, using this resist pattern as a mask, the silicon oxide film 2
The polysilicon film 4 is selectively etched by using as a stopper, the openings 4a,
4b is formed. Thereafter, a driving piezoelectric film (PZT) 6 is formed on the silicon oxide film 2 and a part of the polysilicon film 4 in the opening 4a. Electrode layers (not shown) are formed above and below the piezoelectric film 6.

Next, as shown in FIG. 2C, by selectively etching the back surface of the silicon substrate 1,
The silicon substrate 1 includes an ink supply unit 1a and a pressure generation chamber 1
b are formed in communication. Thereafter, the exposed silicon oxide film 2 is selectively removed by etching. Specifically, the silicon oxide film 2 exists between the pressure generating chamber 1b and the piezoelectric film 6, and also exists between the ink inlet (reference numeral 9a shown in FIG. 1) and the ink supply unit 1a. The silicon oxide film 2 is selectively removed. Thus, the driving substrate 1 is formed.

Thereafter, as shown in FIG. 1, a nozzle substrate 3 having a nozzle opening 3a, a driver IC chip 1
1. The organic film 7 and the substrate 9 are prepared, and the substrate 9 is attached on the organic film 7. Next, the nozzle substrate 3 is attached on the back surface of the driving substrate 1, the organic film 7 is attached on the polysilicon film 4, and the driver IC chip is provided inside the organic film 7 and the substrate 9 and on the upper surface of the polysilicon film 4. 11 is implemented. The IC chip 11 also has a role of protecting the actuator driving section (piezoelectric film). Thereafter, the electrodes 13 and the pads on the upper surface of the IC chip 11 are bonded by wires 13. Thus, the driver IC chip 11 and the bonding wires 13 are electrically connected.

Next, the operation when printing is actually performed using the above-described ink jet head will be described.

The ink is introduced into the ink supply section 1a from the ink introduction port 9a, and the pressure generation chamber 1b is filled with the ink from the ink supply section 1a. Then, an electric field is applied between the upper and lower electrode layers of the piezoelectric film via the bonding wires 13 from the driver IC chip 11 so that the piezoelectric film 6
Flex in the direction of 7. This deflected volume reduces the volume of the pressure generating chamber 1b, whereby a part of the reduced volume of ink is ejected from the nozzle openings 3a and 3b. Printing is performed using the ink thus ejected.

According to the above-described embodiment, an ink jet head can be manufactured by forming the silicon oxide film 2 and the polysilicon film 4 on the driving substrate 1 and performing etching as described above. For this reason, in the conventional inkjet head, two silicon substrates were required to manufacture the driving substrate and the opposing substrate, whereas in the present embodiment, the inkjet head was manufactured using one silicon substrate. it can. That is, the driving substrate 1
And a substrate corresponding to the counter substrate can be manufactured using one silicon substrate. Therefore, the manufacturing process can be simplified and the cost of parts can be reduced.

Further, in the conventional ink jet head, the space formed in the opposite substrate is formed by selectively etching the polysilicon film 4. That is,
By forming a space (opening) 4a in the polysilicon film 4 on the back surface side of the IC chip 11, a structure in which the counter substrate in the conventional ink jet head is unnecessary is obtained. In this embodiment, since the counter substrate is not used as described above,
The height difference between the upper surface of the IC chip 11 and the electrode layer can be made smaller than that in the related art. Specifically, the height difference can be reduced to about half that of the conventional one. Therefore,
The pad on the upper surface of the IC chip 11 and the electrode layer
When bonding is performed, bonding speed can be increased and occurrence of bonding failure can be suppressed. Thereby, the yield can be improved and the reliability of the product can be improved.

The present invention is not limited to the above embodiment, but can be implemented with various modifications.

[0039]

As described above, according to the present invention, it is possible to provide an ink jet head capable of manufacturing a substrate corresponding to a driving substrate and a counter substrate by using one Si substrate, and a method of manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an inkjet head according to an embodiment of the present invention.

FIGS. 2A to 2C are cross-sectional views showing a method of manufacturing the driving substrate and the polysilicon film shown in FIG.

FIG. 3 is a cross-sectional view illustrating a schematic configuration of a conventional inkjet head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Driving substrate 1a Ink supply part 1b Pressure generation chamber 2 Silicon oxide film 3 Nozzle substrate 3a, 3b Nozzle opening 4 Polysilicon film 4a Space (opening) 4b Opening 6 Piezoelectric film (PZT) 7 Organic film (PPS) 9 Substrate 9a Ink inlet 11 Driver IC chip 13 Bonding wire 17 Arrow 101 Driving substrate 101a Ink supply unit 101b Pressure generation chamber 103 Nozzle substrate 103a, 103b Nozzle opening 105 Counter substrate 105a Ink flow path 105b Space 106 Piezoelectric body Film (PZT) 107 Organic film (PPS Film) 109 Substrate 109a Ink inlet 111 Driver IC chip 113, 114 Bonding wire 115 Wiring pattern 117 Arrow

Claims (6)

[Claims] A driving substrate made of Si; a polysilicon film disposed on the driving substrate via an oxide film; an opening provided in the polysilicon film; A driver IC chip disposed on the film; a piezoelectric film disposed on the bottom of the opening and extended on the polysilicon film; and a piezoelectric film formed in the driving substrate and positioned below the piezoelectric film. A pressure generating chamber for storing ink to be pressurized by the piezoelectric film, wherein the opening moves the piezoelectric film when the ink in the pressure generating chamber is pressurized. An ink jet head characterized in that it does not hinder the printing. 2. The ink jet head according to claim 1, further comprising a bonding wire for applying a voltage from a driver IC chip to said piezoelectric film. 3. A nozzle substrate disposed below the driving substrate, and a nozzle opening formed on the nozzle substrate and configured to discharge a part of ink pressurized in the pressure generating chamber. The ink jet head according to claim 1, wherein the ink jet head comprises: 4. The ink-jet apparatus according to claim 1, further comprising an ink supply unit formed in communication with said pressure generation chamber and supplying ink to said pressure generation chamber. head. 5. The ink jet head according to claim 4, further comprising an ink inlet for introducing ink into said ink supply unit. 6. A step of forming a silicon oxide film on a silicon substrate, a step of forming a polysilicon film on the silicon oxide film, a step of forming an opening in the polysilicon film by selective etching, A step of forming a piezoelectric film at the bottom of the opening; a step of forming a pressure generating chamber by selective etching in the silicon substrate and below the piezoelectric film; and a driver IC chip over the opening and the polysilicon film Wherein the pressure generating chamber is for receiving ink that is pressurized by the piezoelectric film, and the opening is configured to press the piezoelectric material when pressurizing the ink in the pressure generating chamber. A method for manufacturing an ink jet head, wherein the method does not hinder the movement of a film.