[sdiy] I must be really strong, cuz I've lifted so many pads!

[James Patchell]

There can be several problems here...

1. Are the pads solder plated?  If not, (i.e. bare copper)...you probably 
need to clean them up shiny bright before soldering.

2. If they are solder plated, were they bright shiny solder plated, or dull 
oxidized...again, need to make them bright and shiny...

3. What type of flux are you using?  Don't know....for challenging solder 
jobs, I recommend Kester 44 resin core solder...it will solder just about 
anything.

4. Finally, lets get down to what causes the pads to lift in the first 
place...one of the primary causes, believe it or not, is water vapor.  If 
there is enough moisture trapped between the copper and the fiberglass, it 
will vaporize and when it does it will literally push the copper right 
off...when I used to work for NASA, PC boards had to go through a process 
they called thremal-vac, where the boards were heated and subjected to a 
vacuum.  The would pull the moister out of the board gradually so when the 
boards where soldered, pads would not lift...it was kind of a pain, but it 
seemed to work.  Now, one thing I have noticed about more modern PC board 
materials is that this no longer seems to be a problem.  In fact, I wash my 
boards in water now, and then solder on them some more without any apparent 
problems.

So, I guess to make any further suggestions on the matter I guess I would 
need to know where you got the PC boards from...i.e. did you make them 
yourself, these come with a kit, or from a PC board vender that you had 
make boards for yourself?

Then again...you could change your name to Bullwinkle...or at the very 
least, make sure Borris isn't trying to destroy you SDIY...

At 09:10 PM 9/6/2004 -0500, David Cornutt wrote:
>Title pretty much says it all... a board I'm trying to finish has
>gotten veeeeery touchy.  I can't apply enough heat to prevent
>a cold-solder joint without lifting the pad.  I'm up to about 20
>jumpers, and the PC board is reverting to the status of
>perfboard.  Any suggestions, or do I need to change my
>name to Bullwinkle?

         -Jim
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