EP0094078A2
Expired / Lapsed
EP
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Multilayer electrostrictive element which withstands repeated application of pulses
Assignee: NEC Corp
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Filing: 1983-05-09
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Granted: —
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Expires: 2003-05-09
Abstract
Abstract In a multilayer electrostrictive element wherein electrostrictive sections (31) are defined by internal electrodes (32) in a stack having a peripheral surface which has a predetermined outline perpendicularly of an axis of the stack, each internal electrode is given an outline which is approximately congruent with the predetermined outline. In order that external electrodes (33, 34) may readily be connected to the internal electrodes grouped into two, each internal electrode may have a peripheral end which is partly recessed from the predetermined outline. Alternatively, the internal electrodes of each group may be connected together by a conductor rod which passes through the electrostrictive sections. For a great number of internal electrodes, an element may be manufactured by laminating conductive-paste-printed green sheets transversely of the stack axis and then sintering the lamination. Each internal electrode may include a ceramic material, such as an electrostrictive material of the electrostrictive sections, another electrostructive material of a lower sintering temperature, or glass.
Inventors
- 👤 Sadayuki Takahashi
- 👤 Masatomo Yonezawa
- 👤 Atsushi Ochi
- 👤 Takeshi Yano
- 👤 Takeshige Hamatsuki
- 👤 Izumu Fukui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 22:49
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/80; H10N30/87; H10N30/871; H10N30/872; H10N30/874; H10N30/877; H10N30/878
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
95 words
In an electrostrictive element comprising a plurality of electrostrictive sections of an electrostrictive material defined in a stack by a plurality of internal electrodes which are perpendicular to an axis of said stack, first means for electrically connecting alternate ones of said internal electrodes together, and second means for electrically connecting others of said internal electrodes together, said stack having a peripheral surface which has a predetermined outline perpendicularly of said axis, the improvement wherein each internal electrode has a peripheral end of an internal electrode outline which is approximately congruent with said predetermined outline.
Claim 2
Dependent Claim
95 words
In an electrostrictive element comprising a plurality of electrostrictive sections of an electrostrictive material defined in a stack by a plurality of internal electrodes which are perpendicular to an axis of said stack, first means for electrically connecting alternate ones of said internal electrodes together, and second means for electrically connecting others of said internal electrodes together, said stack having a peripheral surface which has a predetermined outline perpendicularly of said axis, the improvement wherein each internal electrode has a peripheral end of an internal electrode outline which is approximately congruent with said predetermined outline.
Claim 3
Dependent Claim
50 words
An electrostrictive element as claimed in Claim 1, said peripheral surface having said predetermined outline throughout said stack, wherein each internal electrode has an internal electrode area which is equal to a cross-sectional area of said stack, the peripheral ends of the respective internal electrodes being on said peripheral surface.
Claim 4
Dependent Claim
64 words
An electrostrictive element as claimed in Claim 2, wherein said first means comprises a first external electrode externally of said peripheral surface and in contact with the peripheral ends of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said peripheral surface and in contact with the peripheral ends of said others of the internal electrodes.
Claim 5
Dependent Claim
123 words
An electrostrictive element as claimed in Claim 2, wherein said first means comprises first insulating layer (Claim 4 continued) portions on a first area of said peripheral surface to cover the respective peripheral ends of said others of the internal electrodes leaving first area portions uncovered on said first area and a first conductive layer on said first insulating layer portions and on said first area portions, said second means comprising second insulating layer portions on a second area of said peripheral surface to cover the respective peripheral ends of said alternate ones of the internal electrodes leaving second area portions uncovered on said second area and a second conductive layer on said second insulating layer portions and on said second area portions.
Claim 6
Dependent Claim
124 words
An electrostrictive element as claimed in Claim 2, wherein said first means comprises first layer portions of a photosensitive resin on a first area of said peripheral surface to cover the respective peripheral ends of said others of the internal electrodes leaving first area portions uncovered on said first area and a first conductive layer on said first layer portions and on said first area portions; said second means comprising second layer portions of said photosensitive resin on a seccnd area of said peripheral surface to cover the respective peripheral ends of said alternate ones of the internal electrodes leaving second area portions uncovered on said second area and a second conductive layer on said second layer portions and on said second area portions.
Claim 7
Dependent Claim
126 words
An electrostrictive element as claimed in Claim 2, wherein said first means comprises first metal layer portions on a first area of said peripheral surface to cover the respective (Claim 6 continued) peripheral ends of said alternate ones of the internal electrodes and a first lead wire connecting said first metal layer portions together without brought into c-ontact with the peripheral ends of said others of the internal electrodes, said second means comprising second metal layer portions on a second area of said peripheral surface to cover the respective peripheral ends of said others of the internal electrodes and a second lead wire connecting said second metal layer portions together without brought into contact with the peripheral ends of said alternate ones of the internal electrodes.
Claim 8
Dependent Claim
44 words
An electrostrictive element as claimed in Claim l, said peripheral surface having said predetermined outline throughout said stack, wherein each internal electrode has an internal electrode area perpendicularly of said axis, said internal electrode area being narrower than a cross-sectional area of said stack,
Claim 9
Dependent Claim
144 words
An electrostrictive element as claimed in Claim 7, wherein the peripheral end of each internal electrode comprises a first and a second peripheral part, the internal electrode outlines of the respective internal electrodes being congruent with one another, the first peripheral parts of the respective internal electrodes being on said peripheral surface, the second peripheral parts of said alternate ones of the internal electrodes and of said others of the internal electrodes defining a first and a second area on said peripheral surface, respectively, said first means comprising a first external electrode externally of said second area and in contact with the first peripheral (Claim 8 continued) parts of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said first area and in contact with the first peripheral parts of said others of the internal electrodes.
Claim 10
Dependent Claim
32 words
An electrostrictive element as claimed in Claim 7, wherein the peripheral ends of the respective internal electrodes are substantially on said peripheral surface, each internal electrode having at least one hole therethrough.
Claim 11
Dependent Claim
73 words
An electrostrictive element as claimed in Claim 9, wherein each internal electrode is planar perpendicularly of said axis, said first means comprising a first external electrode externally of said peripheral surface and in contact with the peripheral ends of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said peripheral surface and in contact with the peripheral ends of said others of the internal electrodes.
Claim 12
Dependent Claim
162 words
An electrostrictive element.. as claimed in Claim 9, wherein each internal electrode has a smaller hole of a predetermined inside measure and a greater hole of a greater inside measure so that the smaller and the greater holes of said alternate ones of the internal electrodes are aligned in said stack with the greater and the smaller holes of said others of the internal electrodes, respectively, said first means comprising a first conductor rod filling the smaller holes of said alternate ones of the internal electrodes in contact with said alternate ones of the internal electrodes and passing through said electrostrictive sections and the greater holes of said others of the internal (Claim 11 continued) electrodes, said second means comprising a second conductor rod filling the smaller holes of said others of the internal electrodes in contact with said others of the internal electrodes and passing through said electrostrictive sections and the greater holes of said alternate ones of the internal electrodes.
Claim 13
Dependent Claim
118 words
An electrostrictive element as claimed in Claim 9, wherein each internal electrode comprises a plurality of internal electrode sections, each having a predetermined width and a section end, the internal electrode sections of each internal electrode being arranged parallel to said axis at a predetermined distance with the section ends disposed on said peripheral surface to define a plurality of holes in each internal electrode, said electrostrictive sections being continuous parallel to said axis through the holes in said internal electrodes, each internal electrode further comprising a conductor piece on said peripheral surface and in contact with the ends of the respective internal electrode sections of each internal electrode to serve as a portion of the peripheral end.
Claim 14
Dependent Claim
64 words
An electrostrictive element as claimed in Claim 12, wherein said first means comprises a first external electrode externally of said peripheral surface and in contact with the conductor pieces of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said peripheral surface and in contact with the conductor pieces of said others of the internal electrodes.
Claim 15
Dependent Claim
39 words
An electrostrictive element as claimed in Claim 12, wherein a specific electrode section of the internal electrode (Claim 12 continued) sections of each internal electrode is exposed on said peripheral surface to serve another portion of the peripheral end.
Claim 16
Dependent Claim
86 words
An electrostrictive element as claimed in Claim 14, wherein said first means comprises a first external electrode externally of said peripheral surface and in contact with a predetermined one of the conductor piece and the specific electrode section of each of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said peripheral surface and in contact with a preselected one of the conductor piece and the specific electrode section of each of said others of the internal electrodes.
Claim 17
Dependent Claim
150 words
An electrostrictive element as claimed in Claim 1, wherein said peripheral surface comprises a plurality of first peripheral parts which have said predetermined outline and are separated from one another by a plurality of second peripheral parts, each first peripheral part being defined by a bottom of an indent formed in said peripheral surface with the indents for the respective ones of said first peripheral parts formed in predetermined ones of said electrostrictivs sections, respectively, the peripheral ends of the respective internal electrodes being exposed at least partly on said second peripheral parts, said first means comprising a first external electrode externally of said second peripheral parts and in contact with the peripheral ends of said alternate ones of the internal electrodes, said second means comprising a second external electrode externally of said second peripheral parts and in contact with the peripheral ends of said others of the internal electrodes.
Claim 18
Dependent Claim
34 words
An electrostrictive element as claimed in Claim 1, wherein each internal electrode is made of an electroconductive material which consists essentially of a metal and up to 60% by weight of said electrostrictive material.
Claim 19
Dependent Claim
22 words
An electrostrictive element as claimed in Claim 17, wherein said electroconductive material includes 20 to 30°/o by weight of said electrostrictive material.
Claim 20
Dependent Claim
47 words
An electrostrictive element as claimed in Claim 1, wherein each internal electrode is made of an electroconductive material consisting essentially of a metal and an additional electrostrictive material of a sintering temperature which is lower than a temperature of sintering the electrostrictive material of said electrostrictive sections.
Claim 21
Dependent Claim
23 words
An electrostrictive element as claimed in Claim 19, wherein said electroconductive material includes up to 40% by weight of saia additional electrostrictive material.
Claim 22
Dependent Claim
32 words
An electrostrictive element as claimed in Claim 1, wherein each internal electrode is made of an electroconductive material which consists essentially of a metal and up to 10% by weight of glass.
Claim 23
Dependent Claim
20 words
An electrostrictive element as claimed in Claim 21, wherein said electroconductive material includes 2 to 8% by weight of glass.
References Cited (Backward Citations)
No citation records indexed.
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