Hi Stephen:
I presume you are using no clean solde paste and you are reflowing the solder paste in
forced air convection reflow oven. If these two assumptions are correct, you should be
able to run your process at a peak temperature of 240-245°C. As far soak temperature
goes, you may like to take it upto 170-190°C and may be even as far as 200°C  instead
of 150°C. Make sure that your soak time is around 100-120 seconds (This is to prevent
undue oxidation of the board, component leads and burning up of solder paste flux
residues). Finally, you need to take the board above 225°C for at least 15 seconds at
the coldest part of the board (i.e at the leading edge, near a large component, one of
the edges of the board near the conveyoor rail). This is only to insure that you don't
end up with non-reflowed solder. If you have nitrogen in the oven and if your oxygen
level in the oven is less than 100 ppm, you will have a little more flexibility in the
process.  If you have any further questions, please contact solder paste manufacturer.
Hope this helps.

Kantesh

"Stephen R. Gregory" wrote:

> Hi ya'll!
>
> Most all my reflow profiling experience has been with the typical Sn63Pb37
> alloys. But we'll be getting some products in here later on that will require
> that we use a SN96AG04 alloy (they're boards that go into oil well drill head
> instumentation, hot stuff down there!) Liquidous will be up around 221-229º
> C.
>
> So should I follow the same rules of thumb when it comes creating a profile
> for this stuff...ya' know; don't ramp more than 2-4º C per second, pre-heat
> and soak above 150º C for around a minute and a half, then spike it until
> you're 20-30º above liquidous, and try to be less than a minute while you're
> above liquidous? Or is there some special stuff I should do differently with
> this higher melting point temperature alloy?
>
> 'preciate it!
>
> -Steve Gregory-
>
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