Solid electrolytic capacitor containing a vapor-deposited barrier film
A capacitor comprising a solid electrolytic capacitor element that contains a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric. The capacitor further contains a barrier film that is formed by vapor deposition and that is positioned between the dielectric and the solid electrolyte or overlies the dielectric.
1. A capacitor comprising a solid electrolytic capacitor element that contains a sintered porous anode body, a dielectric that overlies the anode body, and a solid electrolyte that overlies the dielectric, the solid electrolyte containing a plurality of conductive polymer particles containing a poly(3,4-ethylenedioxythiophene) or a derivative thereof and a polymeric counterion;
wherein the capacitor further contains a barrier film that is formed by vapor deposition, the barrier film being positioned between the dielectric and the solid electrolyte;
wherein the vapor-deposited barrier film is formed from a precursor compound including a polyarylene.
2. The capacitor of claim 1 , wherein the barrier film has a thickness of about 10 nanometers or more.
3. The capacitor of claim 1 , wherein the barrier film is formed by atomic layer deposition, molecular layer deposition, physical vapor deposition, plasma-enhanced physical vapor deposition, chemical vapor deposition, plasma-enhanced chemical vapor deposition, or a combination thereof.
4. The capacitor of claim 1 , wherein the polyarylene has the following general structure:
wherein, R1 is alkyl, alkenyl, halo, or haloalkyl; and R2, R3, R4, R5, and R6 are independently selected from hydrogen, alkyl, alkenyl, halo, or haloalkyl, wherein one or more of R1, R2, R3, R4, R5, or R6 are optionally bonded with a second polyarylene ring structure to form a dimer.
5. The capacitor of claim 1 , wherein the polyarylene is 1,4-dimethylbenzene, 1,3-dimethylbenzene, 1,2-dimethylbenzene, toluene, 4-methyl styrene, 3-methylstyrene, 2-methylstyrene, 1,4-divinylbenzene, 1,3-divinylbenzene, 1,2-divinylbenzene, chlorinated polyarylene, [2,2]paracylcophane paracyclophane, or a combination thereof.
6. The capacitor of claim 1 , wherein the barrier film is formed from the precursor compound and a co-reactant.
7. The capacitor of claim 6 , wherein the co-reactant includes a fluorohydrocarbon compound.
8. The capacitor of claim 1 , wherein the solid electrolyte contains a polypyrrole, polythiophene, polyaniline, or a combination thereof.
9. The capacitor of claim 1 , wherein the solid electrolyte contains a conductive polymer formed by in situ solution phase polymerization.
10. The capacitor of claim 1 , wherein the capacitor element further comprises a cathode coating that contains a metal particle layer that overlies the solid electrolyte, wherein the metal particle layer includes a plurality of conductive metal particles dispersed within a resinous polymer matrix.
11. The capacitor of claim 1 , wherein the anode body includes tantalum and the dielectric includes tantalum pentoxide.
12. The capacitor of claim 1 , further comprising an anode termination that is in electrical connection with the anode body, a cathode termination that is in electrical connection with the solid electrolyte, and a housing that encapsulates the capacitor element and leaves exposed a mounting surface of the anode termination and the cathode termination.