Capacitor containing aluminum anode foil anodized in low water content glycerine-phosphate electrolyte
View Patent ↗A capacitor comprising an aluminum anode and a dielectric layer comprising phosphate doped aluminum oxide and process for making the capacitor. Furthermore, the capacitor is formed by the process of: forming an aluminum plate; pre-hydrating the aluminum; contacting the plate with an anodizing solution comprising glycerine, 0.1 to 1.0%, by weight, water and 0.01 to 0.5%, by weight, orthophosphate; applying a voltage to the aluminum plate and determining an initial current; maintaining the first voltage until a first measured current is no more than 50% of the initial current; increasing the voltage and redetermining the initial current; maintaining the increased voltage until a second measured current is no more than 50% of the redetermined initial current, and continuing the increasing of the voltage and maintaining the increased voltage until a final voltage is achieved.
1. A capacitor prepared by the process of
fabricating an aluminum plate;
pre-hydrating said aluminium plate;
contacting said plate with an anodizing solution comprising glycerine, about 0.1 to about 2.0%, by weight, water and about 0.01 to about 0.5%, by weight, orthophosphate;
applying a voltage to said aluminum plate of at least about 220 volts.
2. A device comprising a capacitor of claim 1 .
3. The device of claim 2 wherein said device is an implantable medical device.
4. A capacitor prepared by the process of
fabricating an aluminum plate;
pre-hydrating said aluminium plate;
contacting said plate with an anodizing solution comprising glycerine, about 0.1 to about 2.0%, by weight, water and about 0.01 to about 0.5%, by weight, orthophosphate;
applying a voltage to said aluminum plate and determining an initial current;
maintaining said first voltage until a first measured current is no more than 50% of said initial current;
increasing said voltage and redetermining said initial current;
maintaining said increased voltage until a second measured current is no more than about 50% of said redetermined initial current, and
continuing said increasing said voltage and said maintaining said increased voltage until a final voltage is achieved.
5. A device comprising a capacitor of claim 4 .
6. The device of claim 5 wherein said device is an implantable medical device.
7. A capacitor comprising:
an etched aluminum anode and a dielectric layer comprising phosphate doped aluminum oxide;
prepared by the process of:
forming an aluminum plate;
pre-hydrating said aluminium plate;
contacting said plate with an anodizing solution comprising glycerine, about 0.1 to about 2.0%, by weight, water and about 0.01 to about 0.5%, by weight, orthophosphate;
applying a voltage to said aluminum plate and determining an initial current;
maintaining said first voltage until a first measured current is no more than about 50% of said initial current;
increasing said voltage and redetermining said initial current;
maintaining said increased voltage until a second measured current is no more than 50% of said redetermined initial current, and
continuing said increasing said voltage and said maintaining said increased voltage until a final voltage is achieved.