On 03/31/2017 06:32 AM, David Griffith via cctalk wrote:
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
There USED to be outfits that recycled chips. They had some
system to clean and replate/reflow the leads and align
them. The good ones could counterfeit them for new, you
absolutely could NOT TELL they were not new from the
factory. I have no idea if any of these outfits still
exist. Probably they do, in China!
My P&P would have no problem, it uses mechanical alignment
jaws. But, modern P&P use vision to locate the solder area
of the leads and then position using those coordinates. So,
anything that changes the reflection of the leads or causes
slight misalignment would cause an alignment failure.
Jon
