[Linux-ham] threaded response :: solder choices

Steve Jackson sjackson at radarfind.com
Mon Feb 25 15:38:34 EST 2008

Far too thick for serious surface-mount work.  

>> Agreed, in principle.  However ...
>> In practice, all my "serious surface-mount work" is done 
>> with paste and in a reflow oven, not with wire solder, applied by hand.
>> I use 63/37 eutectic 0.010" for hand SMD work when appropriate 
>> (fine pitch QFP for example) and for stuff that wants to wick ...
>> but even with 0402 parts, in manual assembly, the 0.031" 63/36/2 is
>> quite pleasant to work with, especially considering the '245' type flux

And the silver in the alloy also makes for a higher temperature requirement 

>> This particular solder is not eutectic; however, 63/37 melts at 361 F 
>> and the silver-bearing style has a liquidus spec in a range of 354-372 F
>> In my tests, the 63/36/2 alloy wets at fully 5 degrees F COOLER 
>> than 63/37 eutectic, matching Kester documentation and recommendations

and a protective overspray to prevent oxidation over time

>> AgO is more conductive than the oxide of any other metal, and is 
>> not electro-migratory; no protective spray has ever been mentioned to me
>> Could you cite a source of such a recommendation?

>> We'll have to agree to disagree about this, I guess, and I'll stand 
>> by the manufacturer's specs unless someone can point me to something
>> more authoritative.

More information about the Linux-ham mailing list