31 Mar
2017
31 Mar
'17
11 a.m.
On Mar 31, 2017, at 1:51 PM, allison via cctech
<cctech at classiccmp.org> wrote:
On 03/31/2017 06:32 AM, David Griffith via cctalk wrote:
Is this something that an experienced hand can manually do?
Yes, definitely. 100 lead PQFP is perfectly doable if the lead pitch is not insanely
small. It takes a good fine tip soldering iron (mine is a Weller with a PTS tip), fine
solder (preferably real, i.e., 63/37 non-PC solder). Liquid flux is a big help, as is a
magnifier and bright light or modest magnification microscope.
If you have to do a couple of dozen boards this gets very tedious, but for 5-ish it
isn't a big deal.
paul
I'm down to the last few P112 boards for sale and am pondering
another run of them because demand is steady. One of the biggest
challenges for the last run was getting the QFP-packaged 100-pin
chips[1] in a state such that the pick-and-place robot wouldn't throw
a fit about slight differences in lead position. The stuffing house
insisted that I send them new chips. Pulls, though they looked
perfectly okay to me, were not acceptable. Does anyone here know
anything about pick-and-place robots using pulled 100-pin QFPs,
particularly a stuffing house that can work with such chips and not
screw up?
[1] The now-obsolete super-io chips