Sn-b plating solution and plating method using it

Abstract

The object of the present invention is to prevent generation of whisker in a Pb-free plating layer. Provided is a Pb-free Sn—B plating solution containing tin sulfate, which is a source of Sn ions, and dimethyl amine borane or trimethyl amine borane, which is a source of B ions.

1 . A Pb-free Sn—B plating solution containing tin sulfate, which is a source of Sn ions, and dimethyl amine borane or trimethyl amine borane, which is a source of B ions. 
   
   
       2 . The Pb-free Sn—B plating solution of  claim 1 , wherein the amount of the source of Sn ions is 15 to 50 g/L. 
   
   
       3 . The Pb-free Sn—B plating solution of  claim 1  wherein the amount of B ions is 0.1 to 3.0 g/L. 
   
   
       4 . The Pb-free Sn—B plating solution of  claim 1 , further containing 30 to 70 mL of sulfuric acid. 
   
   
       5 . The Pb-free Sn—B plating solution of  claim 1 , further containing 10 to 40 g/L of cresolsulfonic acid or phenolsulfonic acid. 
   
   
       6 . The Pb-free Sn—B plating solution of  claim 1 , further containing 0.1 to 0.5 g/L of D-Naphtol. 
   
   
       7 . The Pb-free Sn—B plating solution of  claim 1 , further containing 0.1 to 3 g/L of gelatin. 
   
   
       8 . A plating method performed using a Pb-free Sn—B plating solution containing tin sulfate, which is a source of Sn ions, and dimethyl amine borane or trimethyl amine borane, which is a source of B ions. 
   
   
       9 . The plating method of  claim 8 , comprising plating the Pb-free Sn—B plating solution at a current density of 0.5 to 5 A/dm 2 . 
   
   
       10 . The plating method of  claim 8 , wherein the amount of the source of Sn ions is 15 to 50 g/L and the amount of B ions is 0.1 to 3.0 g/L, and the Sn—B plating solution further contains 30 to 70 ml/L of sulfuric acid, 10 to 40 g/L of cresolsulfonic acid or phenolsulfonic acid, 0.1 to 0.5 g/L of β-Naphtol, and 0.1 to 3 g/L of gelatin. 
   
   
       11 . The plating method of  claim 9 , wherein the amount of the source of Sn ions is 15 to 50 g/L and the amount of B ions is 0.1 to 3.0 g/L, and the Sn—B plating solution further contains 30 to 70 ml/L of sulfuric acid, 10 to 40 g/L of cresolsulfonic acid or phenolsulfonic acid, 0.1 to 0.5 g/L of β-Naphtol, and 0.1 to 3 g/L of gelatin.