Method for producing a multilayer element

Patent metadata

Field	Value
Publication number	US-9728706-B2
Application number	US-201113194830-A
Country	US
Kind code	B2
Filing date	Jul 29, 2011
Priority date	Feb 2, 2007
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A method for producing a ceramic multilayer element is disclosed. In an embodiment the method includes forming a plurality of multilayer segments in a green state, wherein each multilayer segment is formed by pressing together a plurality of ceramic layers in the green state and pressing together the multilayer segments in the green state to form a multilayer element that is in the green state. The method further includes sintering the multilayer element that is in the green state to form a ceramic multilayer element that includes the ceramic layers and electrode layers arranged one on top of another, wherein at least one or more of a temperature at which the multilayer segments are pressed together, a pressing force applied during the pressing of the multilayer segments, and/or a duration of the pressing of the multilayer segments are adjusted.

First claim

What is claimed is:

1. A method for producing a ceramic multilayer element, the method comprising:
forming a plurality of multilayer segments in a green state, wherein each multilayer segment has a plurality of ceramic layers in the green state and a plurality of electrode layers, wherein, while forming the plurality of multilayer segments, the multilayer segments are not located one on top of the other but are separate from each other, wherein each multilayer segment is formed separately by pressing together the plurality of ceramic layers and electrode layers at one pressing force;
stacking the plurality of multilayer segments in the green state one on top of the other after forming the plurality of multilayer segments;
pressing together the stacked multilayer segments in the green state thereby forming a multilayer element that is in the green state, wherein the one pressing force is greater than a pressing force applied during the pressing together of the stacked multilayer segments; and
sintering the multilayer element that is in the green state thereby forming the ceramic multilayer element, the ceramic multilayer element comprising the ceramic layers and electrode layers arranged one on top of another,
wherein at least one or more of a temperature at which the stacked multilayer segments are pressed together, the pressing force applied during the pressing together of the stacked multilayer segments, and a duration of the pressing together of the stacked multilayer segments, are adjusted such that the sintered ceramic multilayer element includes a boundary region between the stacked multilayer segments, the boundary region having a tensile strength that causes the boundary region to function as a predetermined breakage region,
wherein the tensile strength is determined by adjusting at least the pressing force applied during the pressing together of the stacked multilayer segments.

2. The method as claimed in claim 1 , wherein forming the multilayer segments comprises pressing together the plurality of ceramic layers into a film stack, each ceramic layer containing an organic binder.

3. The method as claimed in claim 2 , wherein pressing together the plurality of ceramic layers comprises pressing the ceramic layer together at a temperature that is lower than a temperature at which the multilayer segments are pressed together.

4. The method as claimed in claim 3 , wherein the temperature at which the ceramic layers 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.

5. The method as claimed in claim 2 , wherein a binding effect of the organic binder during the pressing together of the multilayer segments differs from a binding effect during the pressing of the ceramic layers.

6. The method as claimed in claim 2 , wherein forming the multilayer segments further comprises separating the multilayer segments from the film stack using a cutting tool.

7. The method as claimed in claim 6 , wherein the multilayer segments are separated from the film stack with a contour shape.

8. The method as claimed in claim 7 , wherein the multilayer segments have one of the following contour shapes: rounded, circular with flattened sides, circular, or oval.

9. The method as claimed in claim 6 , wherein the cutting tool transports the separated multilayer segments.

10. The method as claimed in claim 9 , wherein the cutting tool transports the separated multilayer segments into a cavity for pressing.

11. The method as claimed in claim 10 , wherein the cutting tool comprises a stamping tool and 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.

12. The method as claimed in claim 11 , wherein the multilayer segments are pressed together applying a press pin that presses on an undermost multilayer segment that is in the cavity, toward the stamping tool.

13. The method as claimed in claim 6 , wherein the cutting tool comprises a stamping tool.

14. The method as claimed in claim 2 , wherein the ceramic layers comprise ceramic layers with imprinted metallizations.

15. The method as claimed in claim 1 , wherein the ceramic multilayer element includes the boundary region between the stacked multilayer segments in an end multilayer element that provides the ceramic multilayer element with a function.

16. The method as claimed in claim 15 , further comprising separating the stacked multilayer segments from a film stack using a cutting tool.

17. The method as claimed in claim 16 , wherein the ceramic layers comprise ceramic layers with imprinted metallizations and wherein the multilayer element forms at least a part of a piezoelectric multilayer element.

18. The method as claimed in claim 1 , wherein the tensile strength being determined by adjusting the duration of the pressing together of the stacked multilayer segments.

19. The method as claimed in claim 1 , wherein the tensile strength is determined by adjusting the temperature at which the stacked multilayer segments are pressed together and adjusting the pressing force applied during the pressing together of the stacked multilayer segments.

20. The method as claimed in claim 18 , wherein the tensile strength is determined by adjusting the temperature at which the stacked multilayer segments are pressed together and adjusting the duration of the pressing together of the stacked multilayer segments.

21. The method as claimed in claim 1 , wherein the tensile strength is determined by adjusting the pressing force applied during the pressing together of the stacked multilayer segments and adjusting the duration of the pressing together of the stacked multilayer segments.

22. The method as claimed in claim 1 , wherein the tensile strength is determined by adjusting the temperature at which the stacked multilayer segments are pressed together, adjusting the pressing force applied during the pressing together of the stacked multilayer segments, and adjusting the duration of the pressing together of the stacked multilayer segments.

23. The method as claimed in claim 1 , wherein the stacked multilayer segments are pressed together with a height of 0.8 mm to 1.2 mm.

24. The method as claimed in claim 1 , wherein the stacked multilayer segments are pressed to produce the ceramic multilayer element with a height of 70 mm to 100 mm.

25. The method as claimed in claim 1 , wherein the stacked multilayer segments are pressed together with a cross-sectional area of less than 110 mm 2 .

26. The method as claimed in claim 1 , wherein the stacked multilayer element is debinded.

27. The method as claimed in claim 1 , wherein the stacked multilayer element forms at least a part of a piezoelectric multilayer element.

28. The method as claimed in claim 1 , wherein the predetermined breakage region runs parallel to the ceramic layers and has reduced tensile strength, the predetermined breakage region being localized between adjacent multilayer segments and in pails of the ceramic layers of the adjacent multilayer segments.

29. The method as claimed in claim 28 , wherein the predetermined breakage region is partially contained in an electrode layer that is arranged between adjacent ceramic layers.

Assignees

• Kuegerl Georg
• Bauer Wolfgang
• Reinisch Manfred
• Aldrian Franz
• Ottlinger Marion
• Epcos Ag

Inventors

• Kuegerl Georg
• Bauer Wolfgang
• Reinisch Manfred
• Aldrian Franz
• Ottlinger Marion

Classifications

• H10W99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• Y10T29/49126

  Assembling bases · CPC title

• C04B35/634

  Polymers (C04B35/636 takes precedence) · CPC title

• H01L41/083

  Electricity · mapped topic

• H01L2924/09701

  Electricity · mapped topic