Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B18/00—Layered products essentially comprising ceramics, e.g. refractory products
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/09—Forming piezoelectric or electrostrictive materials
  • H10N30/093—Forming inorganic materials
  • H10N30/097—Forming inorganic materials by sintering
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/80—Constructional details
  • H10N30/88—Mounts; Supports; Enclosures; Casings
  • H10N30/883—Additional insulation means preventing electrical, physical or chemical damage, e.g. protective coatings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2315/00—Other materials containing non-metallic inorganic compounds not provided for in groups B32B2311/00 - B32B2313/04
  • B32B2315/02—Ceramics
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
  • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
  • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
  • C04B2237/30—Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
  • C04B2237/32—Ceramic
  • C04B2237/34—Oxidic
  • C04B2237/345—Refractory metal oxides
  • C04B2237/348—Zirconia, hafnia, zirconates or hafnates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
  • C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
  • C04B2237/62—Forming laminates or joined articles comprising holes, channels or other types of openings
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
  • C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
  • C04B2237/68—Forming laminates or joining articles wherein at least one substrate contains at least two different parts of macro-size, e.g. one ceramic substrate layer containing an embedded conductor or electrode
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
  • C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
  • C04B2237/70—Forming laminates or joined articles comprising layers of a specific, unusual thickness
  • C04B2237/704—Forming laminates or joined articles comprising layers of a specific, unusual thickness of one or more of the ceramic layers or articles
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/20—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators
  • H10N30/204—Piezoelectric or electrostrictive devices with electrical input and mechanical output, e.g. functioning as actuators or vibrators using bending displacement, e.g. unimorph, bimorph or multimorph cantilever or membrane benders
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/40—Piezoelectric or electrostrictive devices with electrical input and electrical output, e.g. functioning as transformers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
  • Y10T428/24926—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including ceramic, glass, porcelain or quartz layer

Definitions

• the invention relates to a ceramic body with at least one essentially homogeneous ceramic layer.
• a method for producing the ceramic body is also specified.
• a ceramic body of the type mentioned and a method for its production are known from US Pat. No. 6,260,248 B1.
• the ceramic body is a multi-layer piezo actuator.
• the piezo actuator consists of a large number of ceramic layers arranged one above the other with a ceramic material made of doped lead zirconate titanate Pb (Zr, Ti) 0 3 .
• the ceramic green foils consist of a green ceramic.
• the green ceramic is a not yet compacted ceramic and consists of powdered lead zirconate titanate and an organic binder.
• a layer thickness of the green sheet is, for example, 100 ⁇ m.
• the stack of printed green foils is consolidated.
• the stack is laminated and then subjected to a heat treatment.
• the heat treatment includes debinding of the ceramic green sheets and subsequent sintering.
• the piezo actuator results in a multilayer construction, the individual ceramic layers being essentially homogeneous.
• the entire piezo actuator is inhomogeneous.
• the internal electrodes made of the silver-palladium alloy are arranged in the volume of the piezo actuator.
• the individual phases each form a chemical and physical unit. Both phases are not homogeneously distributed over the entire piezo actuator.
• the object of the present invention is to show how an essentially homogeneous ceramic body can be provided.
• a ceramic body with at least one essentially homogeneous ceramic layer is specified.
• the ceramic body is characterized in that the ceramic layer has a multiplicity of homogeneous ceramic partial layers arranged one above the other.
• a method for producing the ceramic body is also specified to achieve the object.
• the process is characterized by the following process steps: a) Arranging the homogeneous ceramic partial layers one above the other a stack and b) solidifying the stack, the ceramic body being formed with the ceramic layer.
• the basic idea is to build up the ceramic body or a ceramic layer of the ceramic body from a multiplicity of homogeneous ceramic partial layers and thus to obtain a ceramic body with a homogeneous ceramic layer.
• the ceramic partial layers can have the same or different partial layer thicknesses.
• a homogeneous ceramic sublayer consists of a single phase.
• the phase is formed, for example, from a single ceramic material, the composition of which is independent of location. This means that there is no crack and also almost no gradient in the composition of the ceramic material in the ceramic partial layer. It is also conceivable that there are several phases.
• the ceramic layer consists of various ceramic materials. The ceramic materials are ' evenly distributed over the entire. There is no concentration of any of the ceramic materials. Ceramic and non-ceramic phases can also be present. This non-ceramic phase is, for example, an organic binder of a green ceramic.
• the homogeneous ceramic layer is characterized, for example, by a uniform structure. This leads to an improvement in certain properties of the ceramic body compared to a ceramic body with an inhomogeneous ceramic layer.
• the ceramic body is a piezoelectric transformer. A small number of pores, inclusions, foreign phases or other defects in the ceramic layer leads to a relatively high piezo activity in the piezoelectric transformer, for example.
• a homogeneous polarity state is realized, which leads to a uniform mechanical load during operation of the transformer. The result is a long service life and high reliability of the transformer.
• the ceramic sublayer has a ceramic material selected from the group of green ceramics and / or sintered ceramics.
• Sintered ceramic is an at least partially compacted ceramic.
• Green ceramic is a ceramic that has not yet been compacted.
• the ceramic body can be present as a sintered ceramic body or as a green part (non-sintered ceramic body).
• a sintered ceramic body is produced from the ceramic body in the form of a green part.
• ceramic green foils with a green ceramic are used as homogeneous ceramic part layers for producing the ceramic body in the form of a green part.
• These ceramic green films consist, for example, of powdered ceramic material and an organic binder.
• the green foils consist of homogeneously distributed ceramic and non-ceramic material. Standard processes such as slip casting or film casting are used to produce the ceramic green films.
• the powdered ceramic material consists, for example, of calcined ceramic.
• At least one of the ceramic partial layers has a partial layer thickness selected from the range from 5 ⁇ m up to and including 250 ⁇ m.
• the ceramic partial layers in the form of ceramic green foils have very fine powdered ceramic materials with the specified partial layer thicknesses. These very fine powdered ceramic materials lead to an improved chemical homogeneity of the green sheet, a higher sintering activity and thus to a compaction of the ceramic materials that takes place at lower temperatures.
• the sintering temperature is relatively low.
• a grain size distribution (microstructure) within a ceramic partial layer made of a ceramic green sheet is uniform.
• the ceramic layer consisting of the ceramic partial layers is also characterized by this uniform grain size distribution.
• the consolidation of the stack includes, in particular, a heat treatment of the stack.
• the heat treatment is, for example, a debinding of the green ceramic.
• the heat treatment includes sintering the stack.
• At least one electrode layer is arranged on at least one surface section of the ceramic layer. At least one further electrode layer is preferably arranged on at least one further surface section of the ceramic layer in such a way that the electrode layers lie opposite one another and the ceramic layer is arranged between the electrode layers.
• a ceramic body is, for example, a capacitor.
• At least one of the electrode layers is arranged between the ceramic layer and at least one further ceramic layer.
• the ceramic layer is essentially covered by the further ceramic layer.
• the electrode layer is buried by the further ceramic layer.
• the further ceramic layer is designed, for example, in such a way that an electrical and / or mechanical property of the component is not influenced or is influenced only slightly. Performance data of the component are retained.
• the further ceramic layer is very thin, for example.
• the further ceramic layer can also act as a so-called buffer layer. This is advantageous, for example, when the ceramic body is used in an atmosphere that is reactive with the electrode material of the electrode layer. For example, the ceramic body is used in an environment with high humidity.
• the additional ceramic layer during sintering is inert to the ceramic material of the ceramic layer and partial ceramic layers and to a sintering environment.
• the electrode layers are guided to separate, lateral surface sections of the ceramic body.
• an outer metallization is applied to the surface sections.
• the outer metallizations are applied, for example, using thick-film technology or by sputtering.
• an electrical plated-through hole can be provided in the further ceramic layer covering the electrode layer for electrical contacting.
• the . Electrical through-contacting is a through hole (hole) filled with electrically conductive material in the further ceramic layer. It is also conceivable that the additional ceramic layer does not completely, but only partially cover the electrode layer underneath. This leaves a freely accessible contact area of the electrode layer.
• the ceramic material is, for example, a perovskite.
• the ceramic material is a piezoceramic.
• the piezoceramic is preferably a lead zirconate titanate.
• the invention is distinguished by the following particular advantages: by using thin ceramic green foils with the powdered ceramic material, the sintering temperature can be reduced below 1,300 ° C. This has the advantage that certain components of the lead zirconate titanate, such as lead oxide (PbO) or manganese oxide (MnO), which are volatile during the sintering, do not evaporate to the same extent as with comparable block sintering at higher sintering temperatures would occur.
• PbO lead oxide
• MnO manganese oxide
• a harmful reaction with a sintering aid occurs only to a small extent at lower sintering temperatures.
• a surface layer of the ceramic body or the ceramic layer that is in contact with the sintering agent during sintering remains largely homogeneous. The surface layer is not destroyed to a depth of 1 mm to 3 mm, as is customary in block sintering at elevated temperatures. After the ceramic body has been produced, the surface layer does not have to be removed by grinding, sawing or the like.
• Figure 1 shows a section of an embodiment of the ceramic body in the form of a transformer.
• Figure 2 shows a section of an embodiment of the ceramic body in the form of a bending transducer.
• Figures 3A to 3C show various electrical
• each of the partial ceramic layers 3 has a "partial layer thickness of 4 microns of about 20 microns. 20 such ceramic partial layers are arranged one above the other.
• the piezoelectric transformer 11 has a homogeneous ceramic layer 2 with a total layer thickness 5 of approximately 500 ⁇ m.
• the ceramic body 1 is a piezoelectric bending transducer 12 (FIG. 2).
• the homogeneous ceramic layer of the bending transducer consists of five homogeneous ceramic partial layers with partial layer thicknesses of approximately 20 ⁇ m.
• the electrode layers 8 and 10 are guided to an edge of the homogeneous ceramic layer 2 and thus to a lateral surface section 17 of the piezoceramic bending transducer 12.
• the electrode layers 8 and 10 are each covered over a large area by a further ceramic layer 13.
• the layer thickness of the further ceramic layers 13 is approximately 10 ⁇ m.
• the electrode layers 8 and 10 are buried under the further ceramic layers 13.
• the piezoelectric bending transducer 12 can also be used in a moist environment which is reactive towards the electrode material of the electrode layers 8 and 10 and has a high long-term stability.
• the electrode layers 8 and 10 corresponding to the electrode layers 8 and 10 of the transformer 11 of the first exemplary embodiment are not covered by further electrode layers and are freely accessible (cf. FIG. 1).
• the piezoelectric transformer or the piezoelectric bending transducer To manufacture the piezoelectric transformer or the piezoelectric bending transducer, homogeneous ceramic partial layers in the form of ceramic green foils with a green ceramic are used as the starting point.
• the ceramic green foils are arranged one above the other to form a stack (18, FIG. 4).
• a die is used to enable the ceramic green foils to be stacked exactly one on top of the other.
• the stack is subsequently solidified (19, FIG. 4). This is done by uniaxially pressing the stack (laminating). In an alternative embodiment, the solidification takes place by applying isostatic pressure.
• the stack After the lamination, the stack is subjected to a heat treatment.
• the heat treatment includes debinding and subsequent sintering.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Compositions Of Oxide Ceramics (AREA)

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• 2003
  • 2003-08-20 EP EP03750280A patent/EP1537611A1/de not_active Withdrawn
  • 2003-08-20 US US10/527,158 patent/US20050249928A1/en not_active Abandoned
  • 2003-08-20 JP JP2004536830A patent/JP2006512750A/ja not_active Withdrawn
  • 2003-08-20 WO PCT/DE2003/002776 patent/WO2004027888A1/de not_active Application Discontinuation

Non-Patent Citations (2)

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