I agree with these guys suggesting that 600°F is a
high temperature for rework if we mean 600°F measured on the board in in the
molten solder. But I think we are talking set points of the hand tool. There are
a lot of variables in the equation; thermal offset between the point of
measurement and the actual tip, thermal mass of the tip relative to the work
piece, heat transfer area . . . and as stated earlier, flux
type.
All
things being equal 750°F as a set point may be high for some types of equipment;
Pace hand tools for example where the operator can set the tip
offset to compensate for known characteristics of the tips.
Hand soldering
and touch-up is as much skill as science. A skillful operator can achieve good
solder joint characteristics with the correct tip in a APE hand tool can
get good results from set points as low as 500°F.
But 750°F may also be perfectly acceptable; Older
Weller designs with magnetic switches for example. I have never even seen a
500°F tip for those Weller hand tools.
In a
former life, I went down the path the initial poster is taking. I found the 600°
setting on our hand tools caused a lot of trouble. We ultimately compromised at
700° as a maximum set point, and sometimes our operators complained and
used 750°F (which is what they had preferred until I butted
in).
Later,
we added a new brand of hand tool to our production line and 600°F was the best
general purpose temperature, and our operators rarely needed to use setpoints
greater than 650°F.
The
message here is Know Your Process, Know Your Equipment.
Golfers . . . How far does a three iron go? .
. . one with a hickory shaft?
Guy Ramsey
American Competitiveness
Institute
Senior Lab Technician / Instructor
610 362-1200 ext.
107