Electrical generator or motor structure – Piezoelectric polymers
Patent
1996-10-21
1998-09-29
Dougherty, Thomas M.
Electrical generator or motor structure
Piezoelectric polymers
H01L 4108
Patent
active
058149236
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a piezoelectric thin-film device which can convert electric energy to mechanical energy, or vice versa. More particularly, the present invention relates to a piezoelectric thin-film device usable in actuators, pressure sensors, thermal sensors, heads for ink jet recording and the like.
2. Background Art
A piezoelectric device of a three-component system comprising a third component in addition to lead zirconate titanate ("two-component PZT") is known to have good properties. Therefore, a thin piezoelectric device made from the three-component PZT advantageously will enables an ink jet recording head to be further miniaturized.
However, it is difficult to prepare a piezoelectric thin-film device, of a three-component system, having good properties.
So far as the present inventors know, there is no report on a piezoelectric thin film wherein attention has been focused on deviation of lead content in the thicknesswise direction of the piezoelectric thin film and the deviation been regulated to improve good properties of the piezoelectric thin film.
For example, ferroelectric materials using a two-component PZT is disclosed in Applied Physics Letters, 1991, Vol. 58, No. 11, pp. 1161-1163. Although this report discloses in detail properties of the ferroelectric materials, no evaluation is made for the properties of the ferromagnetic materials as an piezoelectric material.
Further, Japanese Patent Laid-Open Publication No. 504740/1993 discloses a recording head using a two-component PZT. It, however, neither discloses nor suggests the fact that, for a three-component system, the regulation of lead content in the thicknesswise direction leads to advantageous results.
SUMMARY OF THE INVENTION
We have now found that, in the case of a piezoelectric thin film using a three-component PZT, the deviation of lead content in the thicknesswise direction has a great effect on the properties thereof. Further, we have established a process for producing a piezoelectric thin film which enables the lead content deviation the thicknesswise direction to be successfully regulated.
Accordingly, an object of the present invention is to provide a piezoelectric thin-film device, having good properties, using a three-component PZT.
The piezoelectric thin-film device according to the present invention comprises: a piezoelectric film of a polycrystalline material; and two electrodes, the piezoelectric film being sandwiched between the two electrodes, wherein the piezoelectric film comprises a three-component PZT containing 5% by mole or more of a third component and having a thickness of not more than 5 .mu.m, and the deviation of Pb content of the piezoelectric film in the thicknesswise direction thereof is within .+-.5% .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the structure of the piezoelectric thin-film device according to the present invention,
FIG. 2 is an explanatory view showing a process for producing an ink jet recording head using the piezoelectric thin-film device according to the present invention, wherein FIG. 2(a) shows a monocrystalline Si substrate 101 having thereon a Si oxide film 102 formed by thermal oxidation, an antidiffusion film 103, a lower electrode 104, and a film 505 as a precursor of a piezoelectric film, FIG. 2(b) an assembly prepared by sintering the precursor film 505 in the assembly shown in FIG. 2(a) to convert the precursor film 505 to a piezoelectric film 105, forming an upper electrode 106 on the piezoelectric film 105, and forming a chamber as an ink cavity 502 in the substrate 101 by etching, FIG. 2(c) an assembly prepared by removing the Si oxide film 501 and a part of the Si oxide film 102, formed by thermal oxidation, by etching, and FIG. 2(d) an assembly prepared by adhering an orifice plate 503 having a nozzle opening 504 to the substrate 101; and
FIG. 3 is a diagram showing another preferred structure of an ink jet recording head using the piezoelectric thin-film device accordin
REFERENCES:
patent: 4565642 (1986-01-01), Jyomura et al.
patent: 4636908 (1987-01-01), Yoshihara et al.
patent: 4862029 (1989-08-01), Kasai et al.
patent: 5032471 (1991-07-01), Sakata et al.
patent: 5093291 (1992-03-01), Kawabata et al.
patent: 5126615 (1992-06-01), Takeuchi et al.
patent: 5141903 (1992-08-01), Kawabata et al.
patent: 5173460 (1992-12-01), Kuang et al.
patent: 5210455 (1993-05-01), Takeuchi et al.
patent: 5430344 (1995-07-01), Takeuchi et al.
patent: 5631040 (1997-05-01), Takuchi et al.
patent: 5643379 (1997-07-01), Takeuchi et al.
patent: 5645753 (1997-07-01), Fukuoka et al.
patent: 5658485 (1997-08-01), Cava et al.
Dougherty Thomas M.
Seiko Epson Corporation
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