So far for prototyping SMT, I've used solder paste and TRIED to
dab a little on each pad, then drop the part into position.  I then hold
the part in position with the point of an Xacto knife and heat up one
pin.  Once that is secured, all the other pins can be heated with a fine
point iron.
        For production, I'm wondering about having our PC house (down the
street) silkscreen on solder paste.  I wonder how long we can store the
boards before the paste dries up.
        Years ago I saw a vapor-phase soldering system at a convention.
It was a Pyrex jar with condensor tubes around the top.  You heat fluid
in the bottom and run water through the condensor.  The fluid vaporizes
and stays below the condensor.  Loaded boards are lowered into the vapor
for a few seconds, soldering all connections.  I haven't seen the system
since then, but it looked pretty neat.
        I also wonder about using a low flow temperature controlled heat
gun for soldering.  High flow blows the parts off the board.
Nontemperature controlled melts parts.  Anyone have any experience with
this?
        Finally, how about a temperature controlled heat gun as a mini
environmental chamber?

Harold



Harold Hallikainen                               phone/fax/bbs +1 805 541
0201
Hallikainen & Friends, Inc.                web
http://slonet.org/~hhallika
PO Box 4737                                         email
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San Luis Obispo, CA 93403-4737     email hhallika@broadcast.net
USA                                                       email
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