Valve metal powder and solid electrolytic capacitor using same

Abstract

A valve metal powder with optimized particle size distribution, and a solid electrolytic capacitor which uses this is provided. A valve metal powder for a solid electrolytic capacitor is used which is an agglomerate powder to be used for manufacturing an anode with a structure in which valve metal powder is formed in a layer on a valve metal base material, and contains at least 90% of all the powder within a particle size range of 1 μm to 50 μm. It is desirable that at least 90% of all the powder is contained within a particle size range of 1 μm to 30 μm. Moreover, preferably the product of BET specific surface area and specific gravity (d 25 ) is greater than 17 m 2 /g.

1 . A valve metal powder for a solid electrolytic capacitor which is an agglomerate powder to be used for manufacturing an anode with a structure in which valve metal powder is formed in a layer on a valve metal base material, and contains at least 90% of all the powder within a particle size range of 1 μm to 50 μm.  
   
   
       2 . A valve metal powder for a solid electrolytic capacitor according to  claim 1 , wherein a product of BET specific surface area and specific gravity (d 25 ) is greater than 17 m 2 /g.  
   
   
       3 . A valve metal powder for a solid electrolytic capacitor according to  claim 1 , wherein said valve metal is tantalum, tantalum alloy, niobium, or niobium alloy.  
   
   
       4 . A valve metal powder for a solid electrolytic capacitor according to  claim 1 , wherein the powder is obtained by spraying and drying of a suspension of niobium pentoxide powder mixed and dispersed in pure water.  
   
   
       5 . A valve metal powder for a solid electrolytic capacitor according to  claim 1 , wherein the powder is obtained by sintering in a vacuum and crushing of reduced potassium tantalite fluoride.  
   
   
       6 . A solid electrolytic capacitor made using the valve metal powder for a solid electrolytic capacitor according to  claim 1.