Lead-free solder, solder joint product and electronic component

Abstract

This invention provides lead-free solders that have excellent oxidation resistance and can be plastically worked easily and well. The lead-free solders and molded products of the lead-free solders can provide solder joint products, particularly electronic components, which are highly reliable, for example, in mechanical strength and joint strength. The lead-free solders, solder joint product, and electronic component are as follows. A lead-free solder comprising a tin (Sn)-base alloy having a tantalum (Ta) content of not less than 0.005% by weight and not more than 2.0% by weight. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 10.0% by weight of zinc (Zn) with the balance consisting of tin (Sn) and unavoidable impurities. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 60.0% by weight of bismuth (Bi) with the balance consisting of tin (Sn) and unavoidable impurities. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 10.0% by weight of indium (In) with the balance consisting of tin (Sn) and unavoidable impurities. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.01% by weight and not more than 7.5% by weight of copper (Cu) with the balance consisting of tin (Sn) and unavoidable impurities. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.01% by weight and not more than 5.0% by weight of silver (Ag) with the balance consisting of tin (Sn) and unavoidable impurities. A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta), not less than 0.01% by weight and not more than 5.0% by weight of silver (Ag), and not less than 0.01% by weight and not more than 7.5% by weight of copper (Cu) with the balance consisting of tin (Sn) and unavoidable impurities. A solder joint product produced by jointing with the above lead-free solder. An electronic component produced by jointing with the above lead-free solder.

1 . A lead-free solder comprising a tin (Sn)-base alloy having a tantalum (Ta) content of not less than 0.005% by weight and not more than 2.0% by weight.  
   
   
       2 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 10.0% by weight of zinc (Zn) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       3 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 60.0% by weight of bismuth (Bi) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       4 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.1% by weight and not more than 10.0% by weight of indium (In) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       5 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.01% by weight and not more than 7.5% by weight of copper (Cu) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       6 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta) and not less than 0.01% by weight and not more than 5.0% by weight of silver (Ag) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       7 . A lead-free solder comprising a tin (Sn)-base alloy comprising not less than 0.005% by weight and not more than 2.0% by weight of tantalum (Ta), not less than 0.01% by weight and not more than 5.0% by weight of silver (Ag), and not less than 0.01% by weight and not more than 7.5% by weight of copper (Cu) with the balance consisting of tin (Sn) and unavoidable impurities.  
   
   
       8 . The lead-free solder according to  claim 1 , wherein said tin-base alloy further comprises at least one additive element (Y) selected from the group consisting of indium and bismuth.  
   
   
       9 . The lead-free solder according to  claim 8 , wherein, in said tin-base alloy, the content of the additive element (Y) selected from the group consisting of indium and bismuth is not more than 10% by weight for indium and not more than 60% by weight for bismuth.  
   
   
       10 . The lead-free solder according to  claim 1 , wherein said tin-base alloy further comprises at least one additive element (X) selected from the group consisting of cobalt (Co), titanium (Ti), nickel (Ni), palladium (Pd), antimony (Sb), and germanium (Ge).  
   
   
       11 . The lead-free solder according to  claim 10 , wherein, in said tin-base alloy, the content of the additive element (X) selected from the group consisting of cobalt, titanium, nickel, palladium, antimony, and germanium is such that, for each of the additive elements (X), the content is not more than 0.5% by weight and, when a plurality of the additive elements (X) are contained, the total content of the plurality of the additive elements (X) is not more than 1.0% by weight.  
   
   
       12 . The lead-free solder according to  claim 1 , which is in a cream, ribbon, filament or rod form.  
   
   
       13 . A solder joint product produced by jointing with a lead-free solder according to  claim 1 .  
   
   
       14 . An electronic component produced by jointing with a lead-free solder according to  claim 1.