And why do you think hydrogen isn't a flux?
-Chuck Harris
On Fri, 18 Oct 2024 13:01:21 -0700 "Ed Marciniak" <edr10000@...>
wrote:
It *IS* possible to solder without flux, using hydrogen in a carrier
gas, but it requires a high enough temperature for the hydrogen to
reduce surface oxides, and a relatively clean (thin oxide) surface.
There is lower flammability limit to consider, as well as whether the
hydrogen might be a problem. I wouldn¡¯t choose to use forming gas to
seal a crystal can, for example.
One might use sputtered gold surfaces devoid of oxides, freshly
plasma cleaned, a gold tin solder preform and a GaAs laser diode chip
vapor phase cleaned, and want a reducing rather than inert carrier
gas, when cleaning flux residue becomes infeasible.
