Re: gEDA-user: OT: lead-free question

[Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx>]

Well I don't expect it to explode ;) And, I think we have already
established that all electronics related technical questions are
exceptable debate foder for this list. So drop the appology and tell us
afterwards what your experiences were.

The issue, I think, is can you solder the lead free device to a board
with a lead based solder and make a good conduct?

I suspect the answer is yes.  If it doesn't seem to work use some more
flux. Inspect the solder conection in the typical method looking for
cold solder joints.

Lead free seems to indicate that the device not only doesn't contain any
significant lead but that it also can withstand the higher temperatures
that lead free solders require. So if you can get a lead based solder to
adhear to the devices pins then the lower solder temperature shouldn't
be a problem to the device. If the device is in a solder ball based
package such as a BGA then you might have to cook the board with the
device at a higher temperature in order to get it connected. If this is
the case and you are including older devices on the same board then the
increased temperature might damage the older devices. In this case a
stratagy of cooking the board with just the non-lead parts first then
attaching and re-cooking the board with the lead based parts might be
the right idea.

This issue of visual inspection for cold solder joints is going to be
more complex with non-lead based solder. This is do to all solder joints
looking shiny (as i recall from the seminar I attended) even if they are
bad with the silver tn based solders.

As always I would look at what ipc has to say about the ROHS issues.
http://leadfree.ipc.org/RoHS_2-0.asp

Also, these thought are comming randomly, if you are working with a good
assembly shop talk to them.

Best Wishes,

Steve Meier




Dave McGuire wrote:
>
>   Hi folks.  I'm sorry for the off-topic post, but this is the best
> collection of relevant talent that I know of.
>
>   A surface-mount chip I've been using is now only available as a
> lead-free product.  I've done *nothing* with lead-free stuff...Can I
> safely solder it using my standard lead-bearing solder?
>
>             Thanks,
>             -Dave
>
> -- 
> Dave McGuire
> Cape Coral, FL
>
>