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Date:	Thu, 10 Sep 2015 18:07:16 -0400
Message-Id:	<201509102207.t8AM7GOh013740@envy.delorie.com>
From:	DJ Delorie <dj AT delorie DOT com>
To:	geda-user AT delorie DOT com
In-reply-to:
	<CAM2RGhSoJTOCovSOfARhH9rWzrPvj2_kP4GVaDG6Zr-910g8mQ AT mail DOT gmail DOT com>
	(geda-user AT delorie DOT com)
Subject:	Re: [geda-user] 5630 LED footprint
References:	<20150910201416 DOT GG16766 AT fi DOT muni DOT cz>
	<20150910234211 DOT e718beb2aa1655d22382c8a6 AT gmail DOT com> <CAM2RGhSoJTOCovSOfARhH9rWzrPvj2_kP4GVaDG6Zr-910g8mQ AT mail DOT gmail DOT com>
Reply-To:	geda-user AT delorie DOT com

> > Usually thermal relief is added to ease hand soldering but it will
> > also make it a very bad heat sink. I guess you have to chose
> > between either hand soldering or heat sink.
> 
> Nicklas : That would defeat the point of using holes (vias really) and
> pads to heat sink the LED.

I've done embedded pad soldering from the back with one large plated
hole.  It took care to get enough heat in without toasting the chip.
IIRC I filled the hole with first flux then solder paste, so it would
be done as soon as enough heat was present.

> What you want to do is have tons of vias and peel back the mask to
> expose more copper to remove the most heat possible.

It's debatable whether bare (shiny) copper or soldermask can dissipate
heat better.  I've heard both ways, although I'm partial to the
argument that a matte black mask would be the best emitter.

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