Copper powder

Abstract

A copper powder that is excellent in weatherability and adapted for use in conductive paste is provided that contains 10-20,000 ppm, preferably 100-2,000 ppm, of Sn. The copper powder is particularly preferably one having an average particle diameter DM of 0.1-2 μm and, further, one wherein the particle diameter of at least 80% of all particles is in the range of 0.5 D M -1.5 D M . This copper powder can be produced, for example, by precipitating Cu metal by reduction of Cu ions in the presence of Sn ions.

1 . A copper powder containing 10-20,000 ppm of Sn.  
     
     
         2 . A copper powder containing 100-2,000 ppm of Sn.  
     
     
         3 . A copper powder according to  claim 1 , whose average particle diameter DM is 0.1-2 μm.  
     
     
         4 . A copper powder according to  claim 1 , whose average particle diameter DM is 0.1-2 μm and wherein the particle diameter of at least 80% of all particles is in the range of 0.5 DM-1.5 DM.  
     
     
         5 . A copper powder according to  claim 1 , obtained by precipitating copper metal by reduction of Cu ions in the presence of Sn ions.  
     
     
         6 . A copper powder according to  claim 1 , obtained by precipitating copper metal by reduction of cuprous oxide containing 10-1,000 ppm of Sn.  
     
     
         7 . A copper powder suitable for use as filler in a conductive paste, containing 10-20,000 ppm of Sn, whose average particle diameter DM is 0.1-2 μm and the particle diameter of at least 80% of all particles is in the range of 0.5 DM-1.5 DM.  
     
     
         8 . A copper powder according to  claim 2 , whose average particle diameter DM is 0.1-2 μm.  
     
     
         9 . A copper powder according to  claim 2 , whose average particle diameter DM is 0.1-2 μm and wherein the particle diameter of at least 80% of all particles is in the range of 0.5 DM-1.5 DM.  
     
     
         10 . A copper powder according to  claim 3 , whose average particle diameter DM is 0.1-2 μm and wherein the particle diameter of at least 80% of all particles is in the range of 0.5 DM-1.5 DM.  
     
     
         11 . A copper powder according to  claim 2 , obtained by precipitating copper metal by reduction of Cu ions in the presence of Sn ions.  
     
     
         12 . A copper powder according to  claim 3 , obtained by precipitating copper metal by reduction of Cu ions in the presence of Sn ions.  
     
     
         13 . A copper powder according to  claim 4 , obtained by precipitating copper metal by reduction of Cu ions in the presence of Sn ions.  
     
     
         14 . A copper powder according to  claim 2 , obtained by precipitating copper metal by reduction of cuprous oxide containing 10-1,000 ppm of Sn.  
     
     
         15 . A copper powder according to  claim 3 , obtained by precipitating copper metal by reduction of cuprous oxide containing 10-1,000 ppm of Sn.  
     
     
         16 . A copper powder according to  claim 4 , obtained by precipitating copper metal by reduction of cuprous oxide containing 10-1,000 ppm of Sn.