Unleaded solder

Abstract

The invention concerns a lead-free solder comprising a bismuth-based alloy. The lead-free solder has a proportion of at least 80 percent by weight of bismuth and a solidus temperature of at least 260° C.

1 . Lead-free solder consisting of an alloy on the basis of bismuth with a proportion of at least 80 percent by weight of bismuth and with a solidus temperature of at least 260° C.  
     
     
         2 . Solder according to  claim 1 , characterised in that this contains silver as a further component.  
     
     
         3 . Solder according to  claim 2 , characterised in that this contains a proportion of 0.5 to 15 percent by weight of silver.  
     
     
         4 . Solder according to  claim 2  or  3 , characterised in that the proportion of silver amounts to at least 1.5 percent by weight.  
     
     
         5 . Solder according to one of  claims 1  to  4 , characterised in that this contains copper as a further component with a proportion of up to 5 percent by weight.  
     
     
         6 . Solder according to one of  claims 1  to  5 , characterised in that this contains antimony as a further component with a proportion of up to 3 percent by weight.  
     
     
         7 . Solder according to one of  claims 1  to  6 , characterised in that this contains zinc as a further component with a proportion of up to 3 percent by weight.  
     
     
         8 . Solder according to one of  claims 1  to  7 , characterised in that this contains indium as a further component with a proportion of up to 3 percent by weight.  
     
     
         9 . Solder according to one of  claims 1  to  8 , characterised in that this contains magnesium as a further component with a proportion of up to 3 percent by weight.  
     
     
         10 . Solder according to one of  claims 1  to  9 , characterised in that this contains arsenic as a further component with a proportion of up to 1 percent by weight.  
     
     
         11 . Solder according to one of  claims 1  to  10 , characterised in that this contains phosphorus as a further component with a proportion of up to 1 percent by weight.  
     
     
         12 . Solder according to one of  claims 1  to  11 , characterised in that this contains tin as a further component with a proportion of up to 3 percent by weight.  
     
     
         13 . Solder according to one of  claims 1  to  12 , characterised in that its liquidus temperature lies below 450° C.  
     
     
         14 . Use of the solder according to one of  claims 1  to  13  for the manufacture of semi-finished products, in particular wires, pastes and tapes.  
     
     
         15 . Use of the solder according to one of  claims 1  to  14  for the soldering of electronic components to a substrate ( 2 ).  
     
     
         16 . Use of the solder according to  claim 15 , characterised in that the electronic components are formed from integrated circuits and/or power semiconductors.  
     
     
         17 . Use of the solder according to one of claims  15  or  16 , characterised in that the substrate is coated with a layer ( 3 ) made of copper, nickel, silver or gold.