Multilayer capacitor having open mode electrode configuration and flexible terminations
A multilayer ceramic capacitor may include a monolithic body and interleaved first and second pluralities of electrodes extending from the first and second ends, respectively, of the monolithic body towards opposite ends of the monolithic body. A first margin distance and a second margin distance may be formed, respectively, between the electrodes and the opposite ends of the monolithic body. First and second external terminations may be respectively disposed along the first end and second end of the monolithic body and respectively connected with the first and second plurality of electrodes. A margin ratio between a length of the monolithic body and the first margin distance and/or second margin distance may be less than about 10. At least one of the first external termination or the second external termination may include a conductive polymeric composition.
1. A multilayer ceramic capacitor, the multilayer ceramic capacitor comprising:
a monolithic body comprising a plurality of dielectric layers stacked in a Z-direction that is perpendicular to a longitudinal direction, the monolithic body having a first end and a second end that is spaced apart from the first end in the longitudinal direction;
a first plurality of electrodes extending from the first end towards the second end of the monolithic body, the first plurality of electrodes being spaced apart from the second end of the monolithic body by a first margin distance;
a second plurality of electrodes extending from the second end towards the first end of the monolithic body, the second plurality of electrodes being spaced apart from the first end of the monolithic body by a second margin distance;
a first external termination disposed along the first end and connected with the first plurality of electrodes, the first external termination comprising a compliant layer including a conductive polymeric composition; and
a second external termination disposed along the second end and connected with the second plurality of electrodes;
wherein:
the monolithic body has a body length in the longitudinal direction between the first end and the second end and a margin ratio between the body length and at least one of the first margin distance or the second margin distance is less than about 10;
the compliant layer has a maximum thickness in the longitudinal direction and a ratio of the first margin distance to the maximum thickness of the compliant layer is greater than about 5; and
an average thickness of the compliant layer is greater than 10 μm.
2. The multilayer ceramic capacitor of claim 1 , wherein the conductive polymeric composition comprises an epoxy resin.
3. The multilayer ceramic capacitor of claim 1 , wherein the conductive polymeric composition comprises conductive particles.
4. The multilayer ceramic capacitor of claim 3 , wherein the conductive particles comprise silver.
5. The multilayer ceramic capacitor of claim 1 , wherein the conductive polymeric composition has a Young's modulus that is less than about 3 GPa as tested in accordance with ASTM D638-14 at about 23° C. and 20% relative humidity.
6. The multilayer ceramic capacitor of claim 1 , wherein the conductive polymeric composition exhibits a volume resistivity that is less than about 0.01 ohm-cm as tested in accordance with ASTM B193-16 at about 23° C. and 20% relative humidity.
7. The multilayer ceramic capacitor of claim 1 , wherein the first external termination further comprises a base layer formed over the first end of the monolithic body, the compliant layer formed over the base layer.
8. The multilayer ceramic capacitor of claim 7 , further comprising a plurality of anchor tabs disposed within the monolithic body and at the first end of the monolithic body, the plurality of anchor tabs connected with the base layer.
9. The multilayer ceramic capacitor of claim 7 , wherein the base layer comprises a conductive metal.
10. The multilayer ceramic capacitor of claim 1 , wherein the first external termination further comprises at least one plated layer formed over the compliant layer.
11. The multilayer ceramic capacitor of claim 10 , wherein the at least one plated layer comprises a first plated layer comprising a first conductive material and a second plated layer comprising a second conductive material, the second conductive material being different than the first conductive material.
12. The multilayer ceramic capacitor of claim 1 , further comprising a floating electrode that is free of electrical connections with each of the first external termination and second external termination.
13. The multilayer ceramic capacitor of claim 1 , wherein the capacitor is free of floating electrodes.
14. The multilayer ceramic capacitor of claim 1 , wherein the first external termination has a total average thickness in the longitudinal direction that ranges from about 25 μm to about 150 μm.
15. The multilayer ceramic capacitor of claim 1 , wherein the first plurality of electrodes are interleaved with the second plurality of electrodes.
16. The multilayer ceramic capacitor of claim 1 , wherein the margin ratio is within a range of 7 to 10.
17. The multilayer ceramic capacitor of claim 1 , wherein the monolithic body has a top surface and a bottom surface opposite the top surface along the Z-direction, wherein the first external termination extends along the top surface and the bottom surface of the monolithic body such that the first external termination along the top surface and the bottom surface of the monolithic body is spaced apart from the second plurality of electrodes in the longitudinal direction, and wherein the second external termination extends along the top surface and the bottom surface of the monolithic body such that the second external termination along the top surface and the bottom surface of the monolithic body is spaced apart from the first plurality of electrodes in the longitudinal direction.
18. The multilayer ceramic capacitor of claim 1 , wherein the second plurality of electrodes is interleaved with the first plurality of electrodes and stacked along the Z-direction.
19. The multilayer ceramic capacitor of claim 18 , wherein the first external termination and the second external termination are mounted to a mounting surface such that the first plurality of electrodes and the second plurality of electrodes extend parallel to the mounting surface.
20. A method for forming the multilayer ceramic capacitor of claim 1 , the method comprising: forming the first plurality of electrodes respectively on a first plurality of dielectric layers; forming the second plurality of electrodes on a second plurality of dielectric layers; stacking the first plurality of dielectric layers and second plurality of dielectric layers in the Z-direction that is perpendicular the longitudinal direction to form the monolithic body such that the first plurality of electrodes extend from the first end of the monolithic body and are spaced apart from the second end of the monolithic body in the longitudinal direction by the first margin distance and such that the second plurality of electrodes extend from the second end of the monolithic body and are spaced apart from the first end of the monolithic body in the longitudinal direction by the second margin distance; forming the first external termination along the first end of the monolithic body that is connected with the first plurality of electrodes; forming the second external termination along the second end of the monolithic body that is connected with the second plurality of electrodes; wherein: the monolithic body has the body length in the longitudinal distance between the first end and the second end, and wherein the margin ratio between the body length and at least one of the first margin distance or the second margin distance is less than about 10; and at least one of the first external termination or the second external termination comprises the conductive polymeric composition.
21. The method of claim 20 , wherein the conductive polymeric composition comprises an epoxy resin and conductive particles.
22. The method of claim 20 , wherein the conductive polymeric composition has a Young's modulus that is less than about 3 GPa as tested in accordance with ASTM D638-14 at about 23° C. and 20% relative humidity.
23. The method of claim 20 , wherein the conductive polymeric composition exhibits a volume resistivity that is less than about 0.01 ohm-cm as tested in accordance with ASTM B193-16 at about 23° C. and 20% relative humidity.
24. The method of claim 20 , wherein forming the first external termination comprises forming a base layer formed over the first end the monolithic body, forming a compliant layer that comprises the conductive polymeric composition over the base layer, and plating at least one plated layer over the compliant layer.
25. The method of claim 24 , further comprising forming a plurality of anchor tabs within the monolithic body and disposed at the first end of the monolithic body, the plurality of anchor tabs connected with the base layer.
26. The method of claim 24 , wherein plating the at least one plated layer comprises plating a first plated layer comprising a first conductive material and plating a second plated layer comprising a second conductive material, the second conductive material being different than the first conductive material.
27. The method of claim 20 , further comprising forming a floating electrode within the monolithic body, the floating electrode being free of electrical connections with each of the first external termination and second external termination.
28. The method of claim 20 , wherein the first external termination has a total average thickness in the longitudinal direction that ranges from about 25 μm to about 150 μm.
29. The method of claim 20 , wherein forming the first external termination comprises forming a compliant layer that comprises the conductive polymeric composition, the compliant layer having an average thickness that ranges from about 3 μm to about 125 μm.
30. A multilayer ceramic capacitor, the multilayer ceramic capacitor comprising:
a monolithic body comprising a plurality of dielectric layers stacked in a Z-direction that is perpendicular to a longitudinal direction, the monolithic body having a first end and a second end that is spaced apart from the first end in the longitudinal direction;
a first plurality of electrodes extending from the first end towards the second end of the monolithic body, the first plurality of electrodes being spaced apart from the second end of the monolithic body by a first margin distance;
a second plurality of electrodes extending from the second end towards the first end of the monolithic body, second plurality of electrodes being spaced apart from the first end of the monolithic body by a second margin distance;
a first external termination disposed along the first end and connected with the first plurality of electrodes, the first external termination comprising a first compliant layer including a conductive polymeric composition, the first compliant layer having a maximum thickness in the longitudinal direction; and
a second external termination disposed along the second end and connected with the second plurality of electrodes;
wherein a ratio of the first margin distance to the maximum thickness of the first compliant layer is greater than about 5; and
wherein an average thickness of the compliant layer is greater than 10 μm.