JPH04185348A - Liquid jet head and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily form nozzles in high density or a multi-nozzle by providing a nozzle through a nozzle plate, a pressure chamber with side walls made of non-monocrystalline silicon, and a piezoelectric element having a structure of consisting of three or more layers. CONSTITUTION:A layer of non-monocrystalline silicon 103 is formed on a nozzle plate 101 provided with a nozzle 102. Then, the non-monocrystalline silicon layer 103 is patterned to form a pressure chamber 105 having side walls 104. Furthermore, the pressure chamber 105 is filled with a sacrifice layer 106, and a piezoelectric element 110 consisting of three layers of a lower electrode 107, a piezoelectric thin film 108 and an upper electrode 109 is provided on the pressure chamber filled with the sacrifice layer 106. In the final step, the sacrifice layer 106 is removed. When a voltage is applied to the portion between the upper and lower electrodes 109, 107 of the piezoelectric element 110, the piezoelectric element 110 is strained, whereby pressure is applied to a liquid in the pressure chamber 105, and the liquid is jetted out of the nozzle 102.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid ejecting head used in an inkjet printer, etc., and a method for manufacturing the same.

[Prior Art] A liquid ejecting head in a conventional inkjet printer is described by Masato Kobayashi et al.
7-284.1983), it was formed of a substrate and a movable plate provided opposite to the substrate. Furthermore, as shown in Japanese Patent Publication No. 60-8953, there is also a liquid ejecting head that utilizes the bending vibration of a rod having a free end.

[Problems to be Solved by the Invention] In a conventional liquid ejecting head consisting of a substrate and a movable plate, a piezoelectric element was attached to the movable plate, so it was difficult to miniaturize the piezoelectric element. Therefore, it has been difficult to increase the density of nozzles that eject liquid or to form multi-nozzles in which nozzles are formed into long lines. In addition, the special public corporation Showa 6
The liquid ejecting heads shown in Nos. 0 to 8953, which utilize the bending vibration of a rod with a free end, also have a structure in which a comb-shaped rod is attached, so there are problems in the manufacture of the rod and alignment with the nozzle. Therefore, it has been difficult to increase the density of nozzles or to use multiple nozzles. Furthermore, since assembly of any of the liquid jet heads is complicated, the liquid jet heads are expensive.

The present invention is intended to solve the above-mentioned problems, and its purpose is to realize a liquid ejecting head that can easily have high nozzle density and multiple nozzles, and can be formed at a lower cost.

[Means for Solving the Problems] In order to solve the problems described above, the liquid ejecting head of the present invention includes a nozzle that penetrates a nozzle plate made of any material, a side wall connected to the nozzle, and a side wall made of non-single crystal silicon. The pressure chamber has a piezoelectric element having a structure of three or more layers on the pressure chamber, and the side wall of the pressure chamber is made of a material containing silicon dioxide as a main component.

Further, the method for manufacturing a liquid ejecting head of the present invention includes a step of forming a film of non-single crystal silicon on a nozzle plate on which a nozzle is formed and patterning it to form a pressure chamber, and a step of filling the pressure chamber with a sacrificial layer. , forming a piezoelectric element on the pressure chamber and then removing the sacrificial layer; the step of forming a film of non-single crystal silicon; the step of forming a film of a material containing silicon dioxide as a main component; It is characterized by the fact that

[Example Figures 1(a) to (e) show examples of the present invention,
FIG. 3 is a cross-sectional view of a liquid ejecting head in which a piezoelectric element is stretched over a pressure chamber in the form of a supporting beam at both ends, in the order of manufacturing steps, and FIG. Hereinafter, the liquid jet head of the present invention and its manufacturing method will be explained according to the manufacturing process. First, nozzle 10
A non-single crystal silicon film 103 is formed on the nozzle plate 101 on which the silicon oxide film 2 is formed.

The nozzle plate 101 may be made of any material such as metal or glass, and the nozzle 102 may be formed by any method such as an etching method or an electroforming method in which a metal layer is grown with the nozzle 102 open. For example, if the nozzle plate 101 is a Ni plate, LPCVD (Low Pre
ssure Chemical Vapor D
If silicon is formed into a film at a substrate temperature of about 600° C. using a deposition method, a non-single-crystal silicon layer 103 is formed.
The cross-sectional view is as shown in FIG. 1(a). Unless a special substrate such as alumina is used, the film 103 becomes polycrystalline silicon even if the film is formed at a high substrate temperature of about 1000°C. Further, if the film is formed at a substrate temperature of 550° C. or lower, 103 becomes amorphous silicon.

Film forming methods include not only LPCVD but also PECVD (Pla
SMA Enhanced CVD) method or sputtering method may also be used.

Then, the non-single crystal silicon layer 103 is patterned to form a pressure chamber 105, resulting in a cross-sectional view as shown in FIG. 1(b).

104 is a side wall of the pressure chamber. The pressure chamber 105 may be formed by wet etching with a mixed aqueous solution of hydrofluoric acid and nitric acid, or dry etching with a mixed gas of carbon tetrafluoride and oxygen. Furthermore, the pressure chamber 105 is filled with a sacrificial layer 106, and the first
The cross-sectional view is as shown in Figure (c). For example, silicon dioxide may be used for the sacrificial layer 106, and may be formed by a coating method and patterned. Of course, it may be formed by the CVD method, or an organic resist or the like may be used for the sacrificial layer 106. On the pressure chamber filled with the sacrificial layer 106, the lower electrode 107, the piezoelectric thin film 108, and the upper chamber 8ii109 No. 3
A piezoelectric element 11O consisting of layers is provided, and the cross-sectional view shown in FIG. 1(d) is obtained. The lower electrode 107 and the upper electrode 109 are made of Pt.
For the piezoelectric thin film 108, piezoelectric materials such as PZT, PbTiO3, ZnO, etc. may be formed by sputtering, vapor deposition, etc., respectively. Finally, the sacrificial layer 106 is removed, resulting in a cross-sectional view as shown in FIG. 1(e). When silicon dioxide is used for the sacrificial layer 106, it can be removed by dipping it in a mixed aqueous solution of hydrofluoric acid, ammonium fluoride, and acetic acid, and when an organic resist is used, it can be removed by immersing it in an appropriate stripping solution.

An example of the operation of the liquid ejecting head formed as described above is as follows. It is assumed that the space surrounding the piezoelectric element 110, the pressure chamber 105, and the nozzle 102 are filled with liquid. Upper and lower electrodes 109 of piezoelectric element 110
．． When a voltage is applied across 107, piezoelectric element 110 is distorted. Then, pressure is applied to the liquid in the pressure chamber 105, and the liquid is jetted outward from the nozzle 102. Next, piezoelectric element 1
When the voltage application between the upper and lower electrodes 109 and 107 of 10 is stopped, the distortion of the piezoelectric element returns to its original state, the liquid in the pressure chamber 105 is depressurized, and liquid is replenished from the space surrounding the piezoelectric element. This liquid ejecting head operates by repeating the above operations.

In this liquid jet head, after forming the nozzle 102, a piezoelectric element 110 consisting of pressure chambers 105, 107 to 109 is formed.
can be formed continuously using thin film formation technology and photolithography technology, so these can be formed precisely and finely. For this reason, the density of the nozzle that ejects liquid is increased,
It has become easier to create multi-nozzles by forming long nozzles in a line shape. Furthermore, the steps required for assembling this liquid jet head are greatly reduced, making it inexpensive. In addition, when forming the pressure chamber 105, the etching of the non-single crystal silicon 103 is automatically stopped by the nozzle plate 101. Therefore, the depth of the pressure chamber 105 is uniform and has good reproducibility, and can be easily controlled by controlling the thickness of the non-single crystal silicon layer 103. As a result, the liquid ejecting characteristics of the liquid ejecting head of the present invention were also good and the reproducibility was good.

Furthermore, although the above embodiment is an example in which the pressure chamber side wall 104 is formed of non-single crystal silicon, it may be formed of a material whose main component is silicon dioxide, for example, silicon dioxide containing about 5 at% of Zr. It's okay. With such an embodiment, when an alkaline liquid is ejected, the amount of silicon dissolved from the pressure chamber side wall 104 can be suppressed, and for example, this liquid ejecting head can be used as an inkjet printer head using alkaline ink. This will be extremely useful when doing so. The liquid ejecting head of such an embodiment includes a step of forming a film of a material containing silicon dioxide as a main component instead of the step of forming a film of non-single crystal silicon 103 described above. The pressure chamber 105 may be formed by patterning the component film. At this time, silicon, organic resist, or the like may be used for the sacrificial layer 106.

FIG. 2 is a perspective view of a liquid ejecting head in which a piezoelectric element is cantilevered above a pressure chamber in an embodiment of the present invention. In this figure, the same symbols as in FIG. 1 represent the same things as in FIG. 1. The operation of this embodiment 8 is similar to that of the embodiment shown in FIG. 1, and the piezoelectric element 110 stretched on a cantilever is distorted to eject liquid. The manufacturing method can be the same, and the effects are similar, such as increasing the density of the nozzle that sprays liquid, making it easier to create multi-nozzles by forming long nozzles in a line, and having good liquid jetting characteristics and good reproducibility. It became.

FIGS. 3(a) and 3(b) respectively show a perspective view and a sectional view of a liquid ejecting head in which a piezoelectric element is fixed and stretched around a pressure chamber in an embodiment of the present invention. In the same figure,
The same symbols as in FIG. 1 represent the same things as in FIG. 1, respectively. 301 is a liquid conduction path, 302 is a liquid storage chamber, 303
is the lower electrode of the piezoelectric element, and is configured to cover the liquid conduction path 301 and the liquid storage chamber 302 from above. Such a structure allows the sacrificial layer to be used not only in the pressure chamber 105 but also in the liquid conduction path 3.
The lower electrode 303 is formed after filling the liquid storage chamber 302 and the lower electrode 303 . The operation of this liquid jet head includes a nozzle 102, a pressure chamber 105, a liquid conduction path 301,
, the liquid storage chamber 302 is filled with liquid, and the piezoelectric element 1
10 is distorted to eject the liquid, and then the piezoelectric element 11
0 strain is returned to its original state, and the pressure chamber 105 is removed from the liquid storage chamber 302.
The effects of the liquid ejecting head of this embodiment, which supplies liquid to the liquid jet head, are not only those described in the embodiments of FIGS. 1 and 2, but also have the following effects. The structure of the peripherally fixed piezoelectric element is stronger than that of a beam supported at both ends or a cantilever beam, and its natural frequency is also large, so that the pressure applied to the liquid in the pressure chamber 105 is large. Therefore, the liquid ejecting head of this embodiment is structurally strong and also has better liquid ejecting characteristics.

The piezoelectric elements in the liquid ejecting heads shown in the examples above all have a three-layer structure, and the lower electrode is in contact with the liquid. The liquid jetting characteristics may be improved by placing a diaphragm under the diaphragm. In the liquid ejecting head of the present invention described above, the nozzle density can be increased and multi-nozzle can be easily achieved as described above, and a line liquid ejecting head having a length of 5 cm with a resolution of 10 dots/mm can be formed. Moreover, by adopting the configuration of the present invention, 100
It is also possible to increase the resolution to about dot/mm. The liquid ejecting head and the method for manufacturing the same according to the present invention can be applied not only to the embodiments described above, but also to a wide range of other applications without departing from the spirit of the present invention. Further, this liquid ejecting head is widely applied not only to inkjet printers but also to other printing devices (for example, copying machines, etc.), coating devices, textile printing devices, and the like.

[Effects of the Invention] As described above, in the liquid jet head according to the present invention, after forming the nozzle 102, the pressure chambers 105, 107 to 109 are
Since the piezoelectric elements 110 consisting of the following can be continuously formed using thin film formation technology and photolithography technology, these can be formed precisely and finely. For this reason, it has become easy to increase the density of nozzles that eject liquid and to form multi-nozzles in which nozzles are formed into long lines. Furthermore, this liquid jet head greatly reduces the steps required to assemble it.
This made it inexpensive. In addition, when forming the pressure chamber 105, the etching of the non-single crystal silicon 103 is automatically stopped by the nozzle plate 101.
The depth of 5 is uniform and has good reproducibility, and can be easily controlled by controlling the thickness of the non-single crystal silicon layer 103. As a result, the liquid ejecting characteristics of the liquid ejecting head of the present invention were also good and the reproducibility was good.

[Brief explanation of the drawing]

FIGS. 1(a) to (e) show the embodiments of the present invention.
FIG. 3(f) is a sectional view of a liquid ejecting head in the order of manufacturing steps, in which a piezoelectric element is stretched over a pressure chamber in the form of a support beam at both ends; FIG. FIG. 2 is a perspective view of a liquid ejecting head in which a piezoelectric element is cantilevered above a pressure chamber in an embodiment of the present invention. FIGS. 3(a) and 3(b) are a perspective view and a sectional view, respectively, of a liquid ejecting head in which a piezoelectric element is fixed and stretched around a pressure chamber in an embodiment of the present invention. 101... Nozzle plate 102... Nozzle 103... Non-single crystal silicon 104... Pressure chamber side wall 105... Pressure chamber 106... Sacrificial layer 107... Lower electrode 108... Piezoelectric thin film 109... Upper electrode 110... Piezoelectric element and above Applicant Seiko Epson Co., Ltd. agent Patent attorney Kizobe Suzuki and 1 other person Figure 1 (a) Figure 1 (b) Figure 1 (c) 1 Figure (d) Figure 1 (e) 101... Nozzle plate 102... Nozzle 103... Non-single crystal silicon UI Figure 3 (a> Figure 3 (b)

Claims (3)

[Claims] (1) A nozzle that penetrates a nozzle plate made of any material,
A liquid ejecting head comprising a pressure chamber connected to the nozzle and having a side wall made of non-single crystal silicon, and a piezoelectric element having a structure of three or more layers provided on the pressure chamber. (2) The liquid jet head according to claim 1, wherein the side wall of the pressure chamber is made of a material containing silicon dioxide as a main component. (3) A step of forming a film of non-single crystal silicon on the nozzle plate on which the nozzle is formed and patterning it to form a pressure chamber, a step of filling the pressure chamber with a sacrificial layer, and forming a piezoelectric element on the pressure chamber. A method for manufacturing a liquid ejecting head, comprising the step of removing the sacrificial layer after that.