Hello, Technet!

	I'm looking for empirical advice on thermal relief sizing.  The
	IPC 275 answer is a maximum copper attach of .160 or .080 (1 or 2
	oz cu), fine for loads but not sufficient for the supply side.

	The application is a pressfit backplane with an intended (oof)
	fountain soldered power connector.  Problem with power connectors
	of late is that we're up to 10 amperes/pin, or to put it another
	way, ~twice the max recommended thermal connection.

	On these particular backplanes there are also reflowed discrete
	components.  None of the manufacturers we're working with are
	using intrusive reflow yet.  (hint, hint?)

	Is anyone having repeatable success using any other guideline?
	The IPC 275 answer does not mention specific soldering process
	but would presumably cover wave.  Will long-and-slow fountain 
	techniques suffice?  To make matters worse, not every pin on the
	connector has so much load (or copper).

	My guess is we're stuck with hand solder or at best messy touchup.

	Best Regards,

        Jeff Seeger                             Applied CAD Knowledge Inc
        Chief Technical Officer                      Tyngsboro, MA  01879
        [log in to unmask]                               508 649 9800

	Anybody remember when boards were flat, green, and nothing could
	touch?