摘要:
A capacitor comprising an aluminum anode and a dielectric layer comprising phosphate doped aluminum oxide and process for making the capacitor. The capacitor has a CV Product of at least 9 μF−V/cm2 at 250 volts. Furthermore, the capacitor is formed by the process of: forming an aluminum plate; 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.
摘要:
A capacitor comprising an aluminum anode and a dielectric layer comprising phosphate doped aluminum oxide and process for making the capacitor. The capacitor has a CV Product of at least 9 μF−V/cm2 at 250 volts. Furthermore, the capacitor is formed by the process of: forming an aluminum plate; 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.
摘要:
Disclosed is a process for the continuous anodizing of aluminum foil for use in aluminum electrolytic capacitors. Specifically, etched anode foil is anodized to relatively low voltage in a two-step reel-to-reel process. The process is particularly useful for anodizing highly-etched aluminum foil for use in surface mount aluminum capacitors containing conductive polymer cathode material. The process is economical and provides high foil quality. Specifically, the process for anodizing aluminum foil comprises anodizing the foil in a first electrolyte a solution, passing the foil through an oven, anodizing the foil in a second anodizing solution wherein the first electrolyte solution and second electrolyte solution each comprise about 5 wt % to about 50 wt % glycerine, about 0.01 wt % to about 0.2 wt % ammonium phosphate, and de-ionized water, and wherein the foil is anodized in the first electrolyte solution for at least 3.5 minutes
摘要:
Aluminum surface mount capacitors containing one or more anode foil coupons are initially anodized in an aqueous phosphate solution in order to produce an anodic oxide film having extreme resistance to hydration and attack by corrosive anions for the purpose of producing surface mount capacitors at high yield and of high stability.
摘要:
Edges of a slit and cut to length foil having a dielectric oxide film on at least one surface are edge formed by edge forming the foil in an aqueous citrate electrolyte, preferably an aqueous ammonium citrate electrolyte, depolarizing the foil, and then edge forming the foil in an aqueous phosphate electrolyte, preferably an ammonium dihydrogen phosphate electrolyte. Using this formation process, a foil with excellent hydration resistance and capacitance is produced.
摘要:
An electrochemical cell for etching a metal workpiece such as an aluminum foil, a method for etching the foil using the electrochemical cell, and foil thus produced is provided. The cell includes an etch tank having an etch electrolyte disposed therein and containing at least a first and a second compartment each containing (i)an etch electrolyte, (ii) a cathode plate, and (iii) an ion exchange membrane separator portion comprising an ion exchange polymeric material effective to substantially retard or prevent reduction of the oxidizing agent or agents present in the etch electrolyte, the first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other; and a metal workpiece such as an aluminum foil anode present in the etch tank and disposed between each said first and second compartments.
摘要:
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.
摘要:
A capacitor comprising an aluminum anode and a dielectric layer comprising phosphate doped aluminum oxide and process for making the capacitor. The capacitor has a CV Product of at least 9 μF-V/cm2 at 250 volts. Furthermore, the capacitor is formed by the process of: forming an aluminum plate; 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.
摘要:
Aluminum surface mount capacitors containing one or more anode foil coupons are initially anodized in an aqueous phosphate solution in order to produce an anodic oxide film having extreme resistance to hydration and attack by corrosive anions for the purpose of producing surface mount capacitors at high yield and of high stability.
摘要:
A method of protecting surface mount capacitors from moisture and oxygen corrosion by applying a thermally curable pre-coat resin to a portion of the terminals of a capacitor and encapsulating the element(s) with a protective resin. The pre-coat resin is substantially rigid at ambient temperatures and flexible at elevated temperatures and is preferably a lactone-containing epoxy resin. The pre-coat resin may be applied to a solder coating-free portion of the terminals by brush or wiper prior to encapsulating the capacitor element(s) with the protective resin.