Multilayer Element and a Method for Producing a Multilayer Element

Abstract

A ceramic multilayer element can be produced by pressing together a plurality of ceramic multilayer segments. Each multilayer segment includes a stack of a plurality of ceramic layers that are pressed together.

1 . A method for producing a ceramic multilayer element by pressing together a plurality of ceramic multilayer segments, each multilayer segment having a stack of a plurality of ceramic layers that are pressed together. 
   
   
       2 . The method as claimed in  claim 1 , further comprising producing the multilayer segment by pressing together a plurality of ceramic films into a film stack, each ceramic film containing an organic binder. 
   
   
       3 . The method as claimed in  claim 2 , wherein a temperature at which the ceramic films are pressed together is lower than a temperature at which the multilayer segments are pressed together. 
   
   
       4 . The method as claimed in  claim 2 , wherein a binding effect of the organic binder during the pressing of the multilayer segments differs from a binding effect during the pressing of the ceramic films. 
   
   
       5 . The method as claimed in  claim 1 , wherein during the pressing of the multilayer segments, the ceramic layers contained therein are in a green state. 
   
   
       6 . The method as claimed in  claim 3 , wherein the temperature at which the ceramic films are pressed together deviates by a maximum of 25% from room temperature, and the temperature at which the multilayer segments are pressed together is between 75° C. and 95° C. 
   
   
       7 . The method as claimed in  claim 1 , wherein the multilayer element includes a boundary region between the multilayer segments in an end multilayer element that provides the ceramic multilayer element with a function, the boundary region having a tensile strength such that causes the boundary region to function as a predetermined breakage region, the tensile strength being determined by adjusting the temperature at which the multilayer segments are pressed together. 
   
   
       8 . The method as claimed in  claim 1 , wherein the multilayer element includes a boundary region between the multilayer segments in an end multilayer element that provides the ceramic multilayer element with a function, the boundary region having a tensile strength that causes the boundary region to function as a predetermined breakage region, the tensile strength being determined by adjusting a pressing force applied during the pressing of the multilayer segments. 
   
   
       9 . The method as claimed in  claim 1 , wherein of the multilayer element includes a boundary region between the multilayer segments in an end multilayer element that provides the ceramic multilayer element with a function, the boundary region having a tensile strength that causes the boundary region to function as a predetermined breakage region, is the tensile strength being determined by adjusting a duration of the pressing of the multilayer segments. 
   
   
       10 . The method as claimed in  claim 2 , further comprising separating the multilayer segments from the film stack using a cutting tool. 
   
   
       11 . The method as claimed in  claim 10 , wherein the multilayer segments are separated from the film stack with a contour shape. 
   
   
       12 . The method as claimed in  claim 11 , wherein the multilayer segments have one of the following contour shapes: rounded, circular with flattened sides, circular, or oval. 
   
   
       13 . The method as claimed in  claim 10 , wherein the cutting tool transports the separated multilayer segments. 
   
   
       14 . The method as claimed in  claim 13 , wherein the cutting tool transports the separated multilayer segments into a cavity for pressing. 
   
   
       15 . The method as claimed in  claim 10 , wherein the cutting tool comprises a stamping tool. 
   
   
       16 . The method as claimed in  claim 15 , wherein the multilayer segments are pressed together by the stamping tool pressing on a face surface of the multilayer segment that was last inserted into the cavity. 
   
   
       17 . The method as claimed in  claim 16 , wherein the multilayer segments are pressed together with the additional use of a press pin that presses on an undermost multilayer segment that is in the cavity, toward the stamping tool. 
   
   
       18 . The method as claimed in  claim 1 , wherein the multilayer segments are pressed together with a height of 0.8 mm to 1.2 mm. 
   
   
       19 . The method as claimed in  claim 1 , wherein the multilayer segments are pressed to produce the ceramic multilayer element with a height of 70 mm to 100 mm. 
   
   
       20 . The method as claimed in  claim 1 , wherein the multilayer segments are pressed together with a cross-sectional area of less than 110 mm 2 . 
   
   
       21 . The method as claimed in  claim 1 , wherein the multilayer element is debinded. 
   
   
       22 . The method as claimed in  claim 1 , wherein the multilayer element is sintered. 
   
   
       23 . The method as claimed in  claim 2 , wherein the ceramic films comprise ceramic films with imprinted metallizations. 
   
   
       24 . The method as claimed in  claim 1 , wherein the multilayer element forms at least a part of a piezoelectric multilayer element. 
   
   
       25 . A multilayer element comprising:
 a stack of ceramic layers and electrode layers arranged one on top of another,   wherein a predetermined breakage region runs parallel to the ceramic layers and has reduced tensile strength, the breakage region being localized between adjacent ceramic layers and in parts of the ceramic layers.   
   
   
       26 . The multilayer element as claimed in  claim 25 , wherein an electrode layer is arranged between the adjacent ceramic layers, and wherein the predetermined breakage region is partially contained in the electrode layer. 
   
   
       27 . The multilayer element as claimed in  claim 25 , wherein the predetermined breakage region is one of a plurality of predetermined breakage regions that are distributed over a height of the multilayer element at regular distances, the distances each comprising a plurality of ceramic layers and electrode layers. 
   
   
       28 . The multilayer element as claimed in  claim 25 , wherein the multilayer element has a plurality of multilayer segments stacked one on top of another, each of the multilayer segments having a plurality of ceramic layers and electrode layers, wherein the predetermined breakage region runs between adjacent multilayer segments and is partially contained in them. 
   
   
       29 . The multilayer element as claimed in  claim 25 , wherein the predetermined breakage region has a porosity that is higher than an average porosity of the ceramic layers in the multilayer element.