It is interesting to note that if you look at one of the winners (Robert
Lacoste) of the Circuit Cellar design contest (Steve Ciarcia's embedded
microcontroller design magazine) ... he addressed many of the issues that
you raised.
http://www.circuitcellar.com/library..._168/index.htm

In fact enough, with a $150 toaster oven and a low-cost controller, he
achieved reflows with good results. A few mfg. were very interested in his
design and approach (Robert has his own consulting company in France).

gb

"crzndog" wrote in message
...
OK, so this is basically emulating the reflow process. The only issue
with this is that there is no real temperature control and you can damage
both the board and the components if you are not careful (as is the case
with all soldering).

I would also like to point out something else about the technique given in
the link below. Bake out! One real issue in SMT soldering is that IC's
have to be baked out if they've been sitting in a normal environmnet
(humidity) since the epoxy absorbs water. The water then gets heated by
the IR reflow process/oven and can cause the IC to crack. The way around
this is to heat the IC/components gently to above 100 deg C (125 deg C is
OK). This bkes out the water. USually in an industrial process this is
done for about an hour or 2. The IC's are then sealed in a waffle tray
and bag with anhydrous silicone crystals to make sure no water gets
reabsorbed. You shoudl only be wary of this if your IC's have been lying
around in a damp warm atmosphere for a few days. For normal prototyping
this is not so much of a problem.

"w9gb" wrote in message
news:Q_vrd.178384$HA.36082@attbi_s01...
Have you seen my new soldering iron?
http://www.seattlerobotics.org/encod...6/oven_art.htm

w9gb


"Tim Wescott" wrote in message
...
Airy R. Bean wrote:
That certainly matches my experience, which I had
put down to being supplie dfrom a reject batch.

So, what can we do as Radio Hams to prevent such
a problem?

How hot does the whole board have to be raised before
applying a solfering iron? Would a hairdryer do?

"Terry Given" wrote in message
...

Larry Brasfield wrote:

Hand soldering can be very hard on SMD ceramic capacitors.
The high temperature gradiant created by applying heat suddenly

--snip--



Folks are starting to experiment with reflow soldering in toaster ovens.
I've read good reports on the web, but have absolutely no personal
experience nor have I even talked to someone who's done it, so I can't
vouch for it. One of these days I'll give it a try, in the meantime you
can search on toaster oven reflow and get a slew of pages.

There's at least one company (www.pcbexpress.com) who'll even make
prototype stencils for your solder paste, although for stuff that's not
too fine you can dispense paste from a syringe.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com