[sdiy] mis-soldered IC....

[Tony Clark]

> i am working on a paia 9700 kit and I soldered in an IC backwards. 
> Argh!..... is there anything i can do 
> to remove it, i havnt been able to heat up all the pins at once. is 
> there any chance of saving the chip?

   Hi Tom,

   There are a few of us on the list who have discovered a rather unorthodox 
approach to unsoldering thruhole components...
   First, have a surface that is relatively tough and you don't mind 
getting hot solder on.
   Second, hold the board in one hand and soldering iron in the other.
   Next, heat one lead up until the solder joint has some good thermal 
energy stored in it (no more than three seconds!)...
   Then quickly slam the board down against the corner of your work 
surface (solder side down).  If done right, the hot solder should be 
expelled from the thruhole connection.
   What you should have left is an open hole with the part lead bonded to 
one side by a very small amount of solder.  You can then use a pair of 
tweezers or pliers to separate the lead from the pad.  Once you have done 
this with each pin of the part in question, you should be able to remove 
it completely and in tact.
   The reason I like this method is that using a solder sucker or solder 
braid can lead to damaged pads(copper separation from the fiberglass 
laminate!).  Heat is the worst enemy of a circuit board, and 
unfortunately for those without _really good_ skill with an iron, solder 
suckers and braid are a quick way to ruin a board!  The less time your 
soldering iron is on the pad, the better!  And I can't think of a faster 
way to remove solder than by the above described method!

   Plus you have to love the looks people give you when you are violently 
thrashing a circuit board against a table!  ;)  And no, the mechanical 
shock won't really hurt anything.  Most parts have pretty good stress 
ratings, and I have yet to damage anything doing this.  Of course, I 
might be more careful doing it to a vintage piece as opposed to a modern 
assembly.

   Hope that helps!

   Tony

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