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Subject: Re: [geda-user] handsolder QFN packages
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From: "John Griessen (john AT ecosensory DOT com) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
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Date: Wed, 22 Mar 2017 21:41:48 -0600
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On 03/22/2017 04:15 PM, Erich Heinzle (a1039181 AT gmail DOT com) [via geda-user AT delorie DOT com] wrote:
> The key features are a ~3mm thick plate to spread the heat, having the
> 800W hot plate starting at ambient remain on for 250 seconds, then
> turned off, then lifting off the board with the jig at about 280
> seconds, to get a really good fit to the recommended JEDEC heating
> curve.
>
> http://vk5hse.blogspot.com/2011/05/finishing-off-sdr-cube-transceiver.html
>
> being able to lift the board without jostling at 280 seconds avoids
> the problem of thermal inertia of the hot plate continuing to heat the
> board longer than necessary.


Thanks, I'm going to try this with my hotplates too.  Not sure which one will give the best thermal
rise-time, so I'll try both.  Do you know your hotplate wattage and mass?  One of mine is cast iron top,
one aluminum.