Pb free solder alloy

Abstract

The present invention relates to a solder alloy used for mounting or plating electronic components on a printed circuit board (PCB) and the like, and, more particularly, to a Pb-free Sn—Ag based solder alloy which comprises 0.1˜3.0 wt % of Cu, 0.01˜0.5 wt % of Ni, 0.01˜5.0 wt % of Ag, and the balance of Sn. The Pb-free Sn—Ag based solder alloy of the invention has a lower melting point, and highly enhanced wettability and joining strength, compared with the conventional Pb-free solder alloy, thereby preventing generation of bridges.

1 . A Pb-free Sn—Ag based solder alloy, comprising: 0.1˜3.0 wt % of Cu; 0.01˜0.5 wt % of Ni; 0.01˜5.0 wt % of Ag; and the balance of Sn. 
   
   
       2 . The solder alloy according to  claim 1 , wherein the Pb-free Sn—Ag based solder alloy comprises 0.3˜0.8 wt % of Cu, 0.01˜0.1 wt % of Ni, 0.01˜0.5 wt % of Ag, and the balance of Sn. 
   
   
       3 . The solder alloy according to  claim 1 , wherein the Pb-free Sn—Ag based solder alloy comprises 0.3˜0.8 wt % of Cu, 0.01˜0.1 wt % of Ni, 2.0˜4.0 wt % of Ag, and the balance of Sn. 
   
   
       4 . The solder alloy according to  claim 1 , wherein the Pb-free Sn—Ag based solder alloy comprises 2.1˜2.5 wt % of Cu, 0.01˜0.1 wt % of Ni, 0.01˜0.5 wt % of Ag, and the balance of Sn. 
   
   
       5 . The solder alloy according to  claim 1 , wherein the Pb-free Sn—Ag based solder alloy comprises 2.1˜2.5 wt % of Cu, 0.01˜0.1 wt % of Ni, 2.8˜3.2 wt % of Ag, and the balance of Sn. 
   
   
       6 . The solder alloy according to any one of  claims 1  to  5 , further comprising: 0.003˜0.01 wt % of P.