JPH03295655A - Liquid jet head - Google Patents

Abstract

PURPOSE:To reduce the number of steps for manufacturing a liquid jet head by forming a piezo-electric thin film vibrator in a cantilever and covering the vibrator with a part of material of the cantilever. CONSTITUTION:After a SiO2 layer 102, a lower electrode 105, a piezo-electric thin film 106 and an upper electrode 108 are laminated on a surface of a (100) plane single crystal silicon substrate 104 and a cantilever-like piezo-electric thin film vibrator 101 is formed, the silicon substrate 104 is anisotropically etched. The anisotropic etching is stopped when (111) plane 103 is formed as the surface of the silicon substrate. Since the SiO2 layer is left between the piezo-electric thin film vibrators, the anisotropic etching is made in each cantilever section. Therefore, the steps for providing an etch-stop layer and an epitaxial layer can be eliminated, thereby making it possible to reduce the number of the steps requisite for manufacturing a liquid jet head.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid ejecting head used in an inkjet printer or the like, and particularly to a liquid ejecting head using a piezoelectric element.

[Prior Art] As shown in Japanese Patent Publication No. 60-8953, a liquid ejecting head in a conventional inkjet printer uses a piezoelectric vibrator having a cantilever structure to deflect and vibrate with a pulse voltage corresponding to a print signal. A type of ink droplet is known that applies pressure to the ink droplet.

[Problems to be Solved by the Invention] In a conventional liquid ejecting head consisting of a cantilevered piezoelectric thin film vibrator, anisotropic etching was used to form the cantilevered beam. was used to control etching. An epitaxial layer was formed on the etch stop layer to be removed leaving a cantilever, and a 5i02 layer was further formed to serve as the beam. The purpose is to reduce the number of steps by eliminating the steps of forming an etch stop layer and forming an epitaxial layer.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the liquid ejecting head of the present invention includes a nozzle plate having a plurality of nozzles, arranged to face each of the nozzles, and formed on a silicon substrate. and a cantilevered piezoelectric thin film vibrator, and the cantilevered piezoelectric thin film vibrator is displaced by voltage application to increase the pressure of the liquid existing in the gap with the nozzle, thereby ejecting droplets from the nozzle. The liquid ejecting head is characterized in that the periphery of the cantilevered piezoelectric thin film vibrator on the silicon substrate is covered with a part of the material forming the cantilever.

[Embodiment] FIGS. 1(a) and 1(b) are a plan view and a sectional view, respectively, of a cantilever piezoelectric thin film vibrator of a liquid jet head in an embodiment of the present invention. In FIGS. 1(a) and (b), 101 is a cantilevered piezoelectric thin film resonator, and 102 is a part of the cantilevered piezoelectric thin film resonator 5i.
The 02 layer and 103 are (111) planes of silicon, and form grooves that are spaces in which the cantilevered piezoelectric thin film vibrator is displaced. 105 is a lower electrode, 106 is a PZT piezoelectric thin film, 107 is an upper electrode, 108 is a protective layer of 5i02, 1
09 is a nozzle, 110 is a nozzle plate, and 111 is an adhesive layer for bonding the nozzle plate and the silicon substrate. In this structure, first, a 5i02 layer 102 and a lower electrode 105 are formed on a (100) plane single crystal silicon substrate 104.
, after laminating the piezoelectric thin film 106, the upper electrode 107, and the protective layer 108 to form the cantilever piezoelectric thin film vibrator 101,
Anisotropic etching of the silicon substrate 104 is performed.

Etching stops when the surface of the silicon substrate is covered with the (111) plane 103. Since the 5i02 layer was left between the cantilever piezoelectric thin film resonators, the anisotropic etching was performed on each piece. Now works on each beam part. Since the (111) plane is tilted approximately 55 degrees with respect to the 100) plane, if a 100 μm wide part of the (100) plane is anisotropically etched, the width will be 100 μm and the depth will be 71 μm.
If the widths of the grooves that can be formed are made the same, the depths of all the grooves will be the same.

FIG. 2 is a plan view showing another embodiment of the liquid ejecting head of the present invention, in which the supply of ink to the liquid ejecting head is improved. In the same figure, the same symbols as in FIG. 1 represent the same things as in FIG. 1.
The two layers 102 are patterned to form a cantilever piezoelectric thin film vibrator 101. After this, a hole 212 penetrating the silicon substrate is made using a laser. This hole 212 becomes an ink supply path, and ink flows from the back side of the substrate into the groove portion surrounded by the (111) plane 103. Most of the ink supplied to each groove is directly supplied from the hole 212. .

Therefore, the influence of ink supply to any groove on adjacent grooves is reduced, making it possible to increase the frequency of ink ejection and increase the density of cantilevers. The groove for forming the beam can also be shared by multiple beams as shown in the same figure.

The method of forming such a cantilever structure is not limited to the above method. In addition, hole 2 that penetrates the board
The method of forming 12 is not limited to the above method, and for example, methods such as anisotropic etching and laser assisted etching can also be used. In addition, piezoelectric thin films are not limited to PZT, and there are other types of PZT as well.
T, P b T i03, LiTaO3, LiNb
O3, BaTiO3, etc. can also be used.

In the liquid ejecting head as described above, since the cantilever piezoelectric thin film vibrator 101 can be formed using photolithography technology, it can be formed precisely and minutely. In particular, it is possible to easily control the size and thickness of the cantilever beam, which largely governs the liquid ejection characteristics of a liquid ejection head having such a structure. For this reason, the density of the nozzle that performs liquid injection is increased,
It became easy to create multi-nozzles by forming long nozzles in a line shape, and it was possible to form a line liquid jet head with a length of 5 cm at a resolution of 10 dots/mm.

The liquid ejecting head of the present invention can be applied not only to the embodiments described above, but also to a wide range of applications without departing from the spirit of the present invention. , typewriters, copy machine output, etc.), coating equipment, textile printing equipment, etc.

[Effects of the Invention] As described above, according to the present invention, by covering the periphery of the piezoelectric thin film vibrator of the cantilever beam with a part of the material forming the cantilever beam, an appropriate depth can be obtained. Cantilever beams can now be formed using anisotropic etching, which automatically terminates at . This makes it possible to omit extremely time-consuming processes such as epitaxial layer formation, which has a great effect.In addition, regarding ink supply, the ink supplied through the holes cut through the substrate is Since it flows directly into the grooves of the cantilever beams, there is little influence on the grooves of other cantilever beams, making it possible to drive without crosstalk.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are a plan view and a sectional view, respectively, of a liquid jet head in an embodiment of the present invention. FIG. 2 is a plan view of a liquid ejecting head in another embodiment of the present invention. 101...Cantilever piezoelectric thin film vibrator 102...5
i02 layer 103...Silicon (111) surface 104...Silicon substrate 105...Lower electrode 106...Piezoelectric thin film 107...Upper electrode 108...Protective film 109...Nozzle 110... Nozzle plate 111...adhesive layer 212...hole

Claims (1)

[Claims] A nozzle plate having a plurality of nozzles, and a cantilever piezoelectric thin film vibrator disposed opposite each of the nozzles and formed on a silicon substrate, and the cantilever piezoelectric thin film vibrator is displaced by applying a voltage. In a liquid ejecting head that increases the pressure of the liquid existing in a gap with the nozzle to eject droplets from the nozzle, the periphery of the cantilevered piezoelectric thin film vibrator on the silicon substrate is cantilevered. A liquid ejecting head characterized in that a beam is covered with a part of a material forming the beam.