Rudy
I doubt whether hydrazine compounds would be permitted in Europe. As
soon as the HBr adjunct is driven off during the soldering process, you
would be left with the hydrazine. I believe that glutamic acid
hydrobromide is also used and performs quite well (plus some other amino
acid hydrobromides). I haven't heard of amine hydrobromides for HASL but
I think they have been used in some w/s soldering fluxes.
My personal reaction to your post is that, if I thought a commercial
flux contained hydrazine compounds today (yes, I know we had them as
rosin flux activators several decades ago), I would cry it out loud from
the rooftops to try and persuade users to abandon them illico
prestissimo, con veloce.
Brian
[log in to unmask] wrote:
>
> The principal, and I suspect the ONLY, reason for using Hydrobromic Acid
> (HBr) in a HASL is to solubilize Hydrazine.
>
> Hydrazine Hydrobromide is quite soluble, the Hydrochloride is not.
>
> Hydrazine is the best HASL activator known (at least to this vendor), and
> gives good fluxing, even on boards that have sat around too long.
>
> Further, the toxicity of Hydrazine Hydrobromide is "officially" unknown, so
> it does not have to be listed on the MSDS, or at least that is clearly the
> interpretation of many vendors. So, the only thing you need to put on the
> MSDS is the HBr,
>
> And, of course, the actual toxicity of Hydrazine Hydrobromide is formidable...
> A scarey thought. It is probably as carcinogenic as straight Hydrazine.
>
> Rudy Sedlak
> RD Chemical Company
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