[TowerTalk] DIN Connectors You Can't Solder To

[Ian White GM3SEK]

Martin Ewing - AA6E wrote:
>"Reduction of Hazardous Substances" (RoHS) is a European initiative 
>which requires manufacturers to use non-lead-bearing solder for 
>commercial electronics devices, among other practices.  You have to 
>follow these rules if you want to sell in EU -- in practice, the world 
>electronics business is following suit.
>
>See
>http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directi
>ve
>
>The rules don't apply to hobbyists, but most of the stuff we will buy 
>will be RoHS compliant.  In practice, this means that soldering is 
>trickier because you have to use higher temperature solders.
>

Tin/lead solder will continue to be available. Assuming the US 
regulations follow those already existing in Europe, tin/lead solder 
will be legal to sell, legal to buy, and legal for us to use.

The European regulations only apply to items that are "put on the 
market", a closely-defined legal term that does not include home-built 
equipment. Products put on the market before the start date (in Europe, 
that was July 2006) are also exempt, of course.

The higher melting point of lead-free solders is not the only reason to 
continue using tin/lead solder whenever we can. Hand soldering involves 
a lot of variability, and lead-free solders are much less tolerant of 
process variations before the joints become unreliable. It is also very 
difficult to tell the quality of a lead-free joint from the look of it - 
to anyone raised on tin/lead, all lead-free joints look rough... and 
some of them probably are.

Tin/lead solder is compatible with the RoHS-compliant plating finishes 
that amateurs are likely to encounter on components and boards, the most 
common of which is pure tin. I don't believe the RoHS regulations should 
be blamed for this particular problem with the DIN connectors - along 
with the low-melting plastic, this is simple incompetence.

The one thing we cannot legally do is use tin/lead solder to repair a 
modern product that was 'born lead-free'. On the other hand, I feel sure 
there's a lot of that being done on the quiet, because SMD repairs are 
already tricky enough without the added difficulties of lead-free 
solder. And if a small quantity of tin/lead solder can make a good 
repair, and can save the equipment from being scrapped, then any 
environmentalist - and any bureaucrat - should agree that is the right 
thing to do.


-- 

73 from Ian GM3SEK         'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek