US 12,476,052 B2
Delamination-resistant solid electrolytic capacitor
Jiri Navratil, Veseli nad Moravous (CZ); Lotfi Dejbara, Paris (FR); Martin Biler, Lanskroun (CZ); and Jan Petrzilek, Usta nad Orlici (CZ)
Assigned to KYOCERA AVX Components Corporation, Fountain Inn, SC (US)
Filed by AVX Corporation, Fountain Inn, SC (US)
Filed on Jun. 19, 2019, as Appl. No. 16/445,282.
Claims priority of provisional application 62/687,965, filed on Jun. 21, 2018.
Prior Publication US 2019/0392995 A1, Dec. 26, 2019
Int. Cl. H01G 9/028 (2006.01); H01G 9/04 (2006.01); H01G 9/07 (2006.01); H01G 9/10 (2006.01); H01G 9/15 (2006.01)
CPC H01G 9/028 (2013.01) [H01G 9/04 (2013.01); H01G 9/07 (2013.01); H01G 9/10 (2013.01); H01G 9/15 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A solid electrolytic capacitor comprising:
a capacitor element that contains a sintered porous anode body that includes tantalum, a dielectric that overlies the anode body that includes tantalum pentoxide, a solid electrolyte that overlies the dielectric, an external polymer coating that overlies the solid electrolyte, and a cathode coating that overlies the solid electrolyte that contains a metal particle layer that includes a plurality of conductive metal particles and optionally a carbon layer positioned between the metal particle layer and the solid electrolyte, wherein the solid electrolyte contains an inner layer that includes an intrinsically conductive polymer having repeating units of the following formula:

OG Complex Work Unit Chemistry
wherein,
R is (CH2)a—O—(CH2)b-L, wherein L is a bond or HC([CH2]c(H);
a is an integer from 0 to 10;
b is an integer from 1 to 18;
c is an integer from 0 to 10;
Z is a sulfonate ion;
and X is a cation;
and an outer layer that contains pre-polymerized conductive polymer particles, wherein pre-polymerized conductive polymer particles of the outer layer contain a polymeric counterion, and further wherein the capacitor element defines an upper surface, lower surface, front surface, rear surface, first side surface, and second side surface;
an anode lead extending from the front surface of the capacitor element;
an anode termination that is in electrical connection with the anode lead and a cathode termination that is in electrical connection with the solid electrolyte;
an interfacial coating that comprises a hydrophobic resinous material comprising a fluoropolymer formed from fluoroalkyl (meth)acrylate;
a casing material that encapsulates the capacitor element, the anode lead, and the interfacial coating and is in contact with the interfacial coating, wherein the casing material comprises an inorganic oxide filler that includes silica and a resinous matrix that includes an epoxy resin;
wherein the solid electrolytic capacitor demonstrates an initial equivalent series resistance of about 200 mohms or less when measured at a frequency of 100 kHz and a temperature of about 23° C. and an initial capacitance of about 30 nanoFarads per square centimeter or more when measured at a frequency of 120 Hz and a temperature of about 23° C., further wherein the solid electrolytic capacitor has a ratio of an equivalent series resistance and a capacitance after being exposed to a temperature of about 125° C. for 240 hours to the initial ESR and the initial capacitance of about 2.0 or less.