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Greg Valdman

#12427

Shielding | 4 March, 1999

Our vendor proposed to supply us with shields made out of Cold Rolled Steel (CRS) electroplated with Sn (50 - 150 minches). Should I be concerned with solderability or are there a better alternatives to tin finish?

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Earl Moon

#12428

Re: Shielding | 4 March, 1999

| Our vendor proposed to supply us with shields made out of Cold Rolled Steel (CRS) electroplated with Sn (50 - 150 minches). Should I be concerned with solderability or are there a better alternatives to tin finish? | No matter the base metal, electroplated copper followed by electroplated tin lead followed by a reflow process is the best solderable surface finish to prevent excessive oxidation because it is now the most homogeneous surface available to ensure solderability. Tin, alone, often oxidizes beyond hope of achieving solderability when applied to applications as yours.

Also note how soldering iron tips, made of copper wire, are electroplated with about 3 mils of iron to ensure no oxide formation and no other contaminates are introduced to the solder joint or its formation. Now if you could effectively "tin" the shielding case/barrier you describe, wouldn't that be something? Of course, this was just described above. Damn good stuff, eh?

Earl Moon

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