Samuel
Firstly, you don't say what metal the leads are, nor the finish that has
oxidised. If they are an alloy containing nickel (e.g. Kovar), then you
could be in deep trouble, as you may need a halogenated chemical, going
up to hydrochloric acid. If the problem is lead or lead-tin, then you
may need fluoroboric acid or similar. Etc. Whatever, these are hazardous
chemicals requiring knowledge on HOW to use them safely and they will
produce hazardous wastes which will require correct disposal. As others
have pointed out, you will also require to remove the residues correctly
and measurably, to make the components safe. All this will probably cost
you more than the value of the components, unless they are very exotic
ones.
However, there is probably an easy and cheap solution to your problem:
use a good water-soluble soldering chemistry (flux and/or paste), being
careful that the products are activated with either an amine
hydrochloride or an amino acid hydrochloride. These are usually able to
"cut through" oxidation on any component lead type and they avoid a
separate operation. The down side is that you have to have a good and
reliable cleaning process after soldering/reflow. Compared with rosin or
"no-clean" chemistries, your retouch rate will drop dramatically, even
on non-oxidised component leads, and you will also enjoy a much wider
operating window on the soldering process.
Hope this helps.
Brian
"Samuel.Ares" wrote:
>
> Hello everyone...
>
> We are looking for a certain chemical substance that could help us remove
> oxidation compounds from leads on difficult to solder chips. Something that
> we could dip the leads in just before soldering and that would not be too
> complicated or dangerous to use and store.
>
> Any help would be greatly appreciated.
> SAMUEL ARES
> Process Engineering
> Leitch Technology Int.
> [log in to unmask] <mailto:[log in to unmask]>
> (416) 445-9640 x. 3395
>
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