[sdiy] More SMT

[Scott Gravenhorst]

This is regarding a video which depicted using a Schmartboard to solder a 64 pin 0.5 mm
pitch TQFP package.  The video showed a fine point soldering tip being used and the
process was to use the point of the tip to push solder already on the traces leading to
the IC pins.

I do not have such a soldering tip, but I did have a good quality small chisel tip (I'm
guessing 3/16" wide).  

I first put paste flux on the Schmartboard with a toothpick.  Just a slime coating.  Then
I put the IC onto the board and after several attempts got it lined up.  It's tiny stuff
for me, so I had to use a magnifier (telescope eyepiece in my case) to make sure that the
IC leads lined up with the traces and that all were going to connect properly.  

I taped the board onto my desk with masking tape.  I then taped the IC to the board once
I had it registered correctly.

I then cleaned my iron well and applied a very small amount of solder to the iron and
dragged it while heating both the board traces and the IC pins.

Of course there was a small amount of "too much solder" which made bridges.

I wiped and cleaned the soldering iron as much as I could and re-dragged the same places
on the board.  This caused solder to come out from the bridges and go onto the PCB
traces.  I used the magnifier to look at the solder job and it looks clean.  I will "ring
it out" tomorrow to see if I need to use solder wick.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
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