Wet tantalum capacitor usable without reformation and medical devices for use therewith

Abstract

A therapeutic medical device system comprising an electrolytic capacitor including an anode, cathode and an electrolyte. The anode is anodized in an electrolyte comprises an aqueous solution of alkanol amine, phosphoric acid and an organic solvent preferably defined by formula 1: CH 3 —(OCH 2 CH 2 ) m —OCH 3   Formula 1 wherein m is an integer from 3 to 10.

1 . A therapeutic system comprising a medical device comprising an electrolytic capacitor wherein said electrolytic capacitor comprises an anode and cathode wherein said anode comprises an oxide deposited by electrochemical deposition in an anodizing electrolyte comprising alkanolamine, phosphoric acid and organic solvent.  
     
     
         2 . A therapeutic system according to  claim 1  wherein said organic solvent is selected from the group consisting of monomeric glycols, glycerine, polyethylene glycols, polyethylene glycol monomethyl ethers, polyethylene glycol dimethyl ethers, 2-methyl-1,3-propanediol, diethylene glycol, N-alkyl-2-pyrrolidones and mixtures thereof.  
     
     
         3 . A therapeutic system according to  claim 2  wherein said organic solvent is a compound of Formula 1: 
       CH 3 —(OCH 2 CH 2 ) m —OCH 3   Formula 1 
       wherein m is an integer from 3 to 10.  
     
     
         4 . A therapeutic system according to  claim 3  wherein said m is an integer from 3 to 5.  
     
     
         5 . A therapeutic system device according to  claim 4  wherein said m is 4.  
     
     
         6 . A therapeutic system according to  claim 1  wherein said anodizing electrolyte comprising about 10 to about 70%, by weight, said organic solvent.  
     
     
         7 . A therapeutic system according to  claim 6  wherein said anodizing electrolyte comprising about 25 to about 50%, by weight, said organic solvent.  
     
     
         8 . A therapeutic system according to  claim 1  wherein said anode comprises a metal selected from a group consisting of titanium, nickel, molybdenum, cobalt, stainless steel, tungsten, platinum, palladium, gold, silver, copper, chromium, aluminium, zirconium, hafnium, zinc, iron, vanadium, niobium and tantalum.  
     
     
         9 . A therapeutic system according to  claim 8  wherein said anode comprises tantalum.  
     
     
         10 . A therapeutic system according to  claim 1  wherein said cathode is a conductive metal provided with a semiconductive or metal-like conductive coating.  
     
     
         11 . A therapeutic system according to  claim 10  wherein said cathode is at least one material chosen from a group consisting of carbon or an oxide, nitride, or carbide of a metal.  
     
     
         12 . A therapeutic system according to  claim 11  wherein said cathode comprises a metal selected from a group consisting of tantalum, titanium, nickel, iridium, platinum, palladium, gold, silver, cobalt, molybdenum, ruthenium, manganese, tungsten, zirconium, hafnium, rhodium, vanadium, osmium and niobium.  
     
     
         13 . A therapeutic system according to  claim 12  wherein said cathode comprises a porous ruthenium oxide film provided on a tantalum substrate.  
     
     
         14 . A therapeutic system comprising a medical device comprising an electrolytic capacitor wherein said electrolytic capacitor comprises: 
 an anode of a valve metal anodized by an aqueous anodizing solution comprising phosphoric acid, at least one organic solvent and at least one alkanolamine; and    a metal oxide cathode.    
     
     
         15 . A therapeutic system according to  claim 14  wherein said anodizing solution comprising about 10 to about 70%, by weight, said organic solvent.  
     
     
         16 . A therapeutic system according to  claim 15  wherein said anodizing solution comprising about 25 to about 50%, by weight, said organic solvent.  
     
     
         17 . A therapeutic system according to  claim 14  wherein said anode comprises a metal selected from a group consisting of titanium, tungsten, chromium, aluminium, zirconium, hafnium, zinc, iron, vanadium, niobium, bismuth, antimony and tantalum.  
     
     
         18 . A therapeutic system according to  claim 17  wherein said anode is tantalum.  
     
     
         19 . A therapeutic system according to  claim 14  wherein said cathode is a conductive metal provided with a semiconductive or metal-like conductive coating.  
     
     
         20 . A therapeutic system according to  claim 19  wherein said cathode is at least one material chosen from a group consisting of carbon or an oxide, nitride, or carbide of a metal.  
     
     
         21 . A therapeutic system according to  claim 20  wherein said cathode comprises a metal selected from a group consisting of tantalum, titanium, nickel, iridium, platinum, palladium, gold, silver, cobalt, molybdenum, ruthenium, manganese, tungsten, iron, zirconium, hafnium, rhodium, vanadium, osmium and niobium.  
     
     
         22 . A therapeutic system according to  claim 21  wherein said cathode comprises a porous ruthenium oxide film provided on a titanium substrate.  
     
     
         23 . A therapeutic system according to  claim 14  wherein said anodizing solution comprises about 0.1% to about 2.0%, by weight, phosphoric acid, about 1% to about 70%, by weight, of said organic solvent and about 0.1% to about 10%, by weight, of at least one alkanolamine.  
     
     
         24 . A therapeutic system according to  claim 14  wherein said organic solvent is selected from the group consisting of monomeric glycols, glycerine, polyethylene glycols, polyethylene glycol monomethyl ethers, polyethylene glycol dimethyl ethers, 2-methyl-1,3-propanediol, diethylene glycol, N-alkyl-2-pyrrolidones and mixtures thereof.  
     
     
         25 . A therapeutic system according to  claim 24  wherein said organic solvent is a compound of Formula 1: 
       CH 3 —(OCH 2 CH 2 ) m —OCH 3   Formula 1 
       wherein m is an integer from 3 to 10.  
     
     
         26 . A therapeutic system according to  claim 25  wherein said m is an integer from 3 to 5.  
     
     
         27 . A therapeutic system device according to  claim 26  wherein said m is 4.  
     
     
         28 . A therapeutic system according to  claim 14  wherien said alkanolamine is selected from a group consisting of monoethanol amine, diethanol amine, triethanol amine, ethyl diethanolamine, diethyl ethanolamine, dimethyl ethanolamine and dimethyl amino ethoxy ethanol.  
     
     
         29 . A therapeutic system according to  claim 14  wherein said anodizing solution comprises about 0.1% to about 6%, by weight, of said alkanolamine.  
     
     
         30 . A therapeutic system according to  claim 15  wherein said anodizing solution comprises about 5% to about 35%, by weight, of said organic solvent.  
     
     
         31 . A therapeutic system according to  claim 14  wherein said anodizing solution has a pH of about 4 to about 9.  
     
     
         32 . A method for fabricating a medical device comprising: 
 forming a capacitor comprising the steps of:    preparing a metal anode from a valve metal powder comprising anodizing the metal anode with an aqueous anodizing electrolyte comprising phosphoric acid, at least one organic solvent and alkanolamine;    providing a cathode; 
 activating said anode and said cathode with a working electrolyte;  
   incorporating said capacitor into a circuit; and    incorporating said circuit.    
     
     
         33 . A method according to  claim 32  wherein said anode comprises a metal selected from a group consisting of titanium, tungsten, chromium, aluminium, zirconium, hafnium, zinc, vanadium, niobium, bismuth, antimony and tantalum.  
     
     
         34 . A method according to  claim 33  wherein said anode is tantalum.  
     
     
         35 . A method according to  claim 32  wherein said cathode is a conductive metal provided with a semiconductive or metal-like conductive coating.  
     
     
         36 . A method according to  claim 35  wherein said cathode is at least one material chosen from a group consisting of carbon or an oxide, nitride, or carbide of a metal.  
     
     
         37 . A method according to  claim 36  wherein said cathode comprises a metal selected from a group consisting of tantalum, titanium, nickel, iridium, platinum, palladium, gold, silver, cobalt, molybdenum, ruthenium, manganese, tungsten, iron, zirconium, hafnium, rhodium, vanadium, osmium and niobium.  
     
     
         38 . A method according to  claim 37  wherein said cathode comprises a porous ruthenium oxide film provided on a titanium substrate.  
     
     
         39 . A method according to  claim 32  wherein said anodizing electrolyte has a pH of about 4 to about 9.  
     
     
         40 . A method according to  claim 32  wherein said anodizing electrolyte comprises about 0.1% to about 2.0%, by weight, phosphoric acid, about 1% to about 70%, by weight, of at least one organic solvent and about 0.1% to about 10%, by weight, of at least one alkanolamine.  
     
     
         41 . A method according to  claim 32  wherein said organic solvent is selected from the group consisting of monomeric glycols, glycerine, polyethylene glycols, polyethylene glycol monomethyl ethers, polyethylene glycol dimethyl ethers, 2-methyl-1,3-propanediol, diethylene glycol, N-alkyl-2-pyrrolidones and mixtures thereof.  
     
     
         42 . A method according to  claim 41  wherein said organic solvent is a compound of Formula 1: 
       CH 3 —(OCH 2 CH 2 ) m —OCH 3   Formula 1 
       wherein m is an integer from 3 to 10.  
     
     
         43 . A method according to  claim 42  wherein said m is an integer from 3 to 5.  
     
     
         44 . A method according to  claim 43  wherein said m is 4.  
     
     
         45 . A method according to  claim 32  wherien said alkanolamine is selected from a group consisting of monoethanol amine, diethanol amine, triethanol amine, ethyl diethanolamine, diethyl ethanolamine, dimethyl ethanolamine and dimethyl amino ethoxy ethanol.  
     
     
         46 . A method according to  claim 40  wherein said anodizing solution comprises about 0.1% to about 6%, by weight, of said alkanolamine.  
     
     
         47 . A method according to  claim 40  wherein said anodizing solution comprises about 5% to about 35%, by weight of said organic solvent.  
     
     
         48 . A method according to  claim 40  wherein said anodizing solution comprises about 50% to about 70%, by weight of said organic solvent.  
     
     
         49 . A method according to  claim 32  comprising about 25 to about 50%, by weight, said organic solvent.  
     
     
         50 . A method according to  claim 32  wherein said anodizing solution has a pH of about 3 to about 9.