Tin plating method

Abstract

Tin deposits having greatly reduced whisker formation are provided. Methods of depositing tin layers or films having a reduced tendency to form whiskers are also provided.

What is claimed is:  
     
         1 . A method of reducing tin whisker formation comprising electrodepositing a layer of tin or tin-alloy on a substrate, wherein the tin or tin-alloy layer is substantially free of crystal planes or equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof.  
     
     
         2 . The method of  claim 1 , wherein the intensity of each crystal plane and equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof is less than or equal to 10% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.  
     
     
         3 . The method of  claim 2 , wherein the intensity is less than or equal to 5% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.  
     
     
         4 . A tin or tin-alloy layer having reduced whisker formation, wherein the tin or tin-alloy layer is substantially free of crystal planes or equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof.  
     
     
         5 . The tin or tin-alloy layer according to  claim 4 , wherein the intensity of each crystal plane and equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof is less than or equal to 10% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.  
     
     
         6 . The tin or tin-alloy layer according to  claim 5 , wherein the intensity is less than or equal to 5% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.  
     
     
         7 . An electronic device comprising a tin or tin-alloy layer, wherein the tin or tin-alloy layer is substantially free of crystal planes or equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof.  
     
     
         8 . The electronic device of  claim 7 , wherein the intensity of each crystal plane and equivalent planes thereof forming an angle of 5° to 22° with an adjacent crystal plane or an equivalent plane thereof is less than or equal to 10% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.  
     
     
         9 . The electronic device of  claim 8 , wherein the intensity is less than or equal to 5% of the summarized peak intensities of all observed peaks in an X-ray diffraction spectrum.