Fine copper particles, method for producing fine copper particles and method for producing sintered body

Abstract

One object of the present invention is to provide fine copper particles which are less likely to be deteriorated by oxidation in the atmosphere without being coated with an antioxidant or the like and which can be sintered at a lower temperature. The present invention provides fine copper particles wherein an entire surface is covered with a coating film containing cuprous oxide and having an average film thickness of 1.5 nm or less.

1 . Fine copper particles wherein an entire surface is covered with a coating film containing cuprous oxide and having an average film thickness of 1.5 nm or less. 
     
     
         2 . The fine copper particles according to  claim 1 , wherein an average particle diameter is 500 nm or less. 
     
     
         3 . A method for producing fine copper particles in which fine copper particles having a coating film containing cuprous oxide on a surface are produced by heating copper or a copper compound in a reducing flame formed by a burner,
 wherein the fine copper particles are produced by adjusting a mixing ratio between a combustible gas and a combustion supporting gas which form the reducing flame such that a volume ratio of CO/CO 2  is in a range of 1.5 to 2.4.   
     
     
         4 . A method for producing a sintered body,
 wherein fine copper particles according to  claim 1  are used as a raw material and sintered them in a reducing atmosphere at 150° C. or lower.   
     
     
         5 . A method for producing a sintered body,
 wherein fine copper particles according to  claim 2  are used as a raw material and sintered them in a reducing atmosphere at 150° C. or lower.