31 Mar
2017
31 Mar
'17
10:51 a.m.
On 03/31/2017 06:32 AM, David Griffith via cctalk wrote:
Is this something that an experienced hand can manually do?
Of all the CP/M platforms its one of the few I haven't done. But
it keeps popping after I've long figured its long gone.
I'm not afraid of SMT as I proto using 0603 and 0402 parts
at uhf/microwave freehand.
Baving delt with layouts for BGA and large pinout devices usually getting
fiducial marks on the board so it can locate and position without
optical works.
One time the board designer messed up and we had to use existing fixed
points
for that. PITA but it worked. After that I got into the board layout
bit and DFM.
Allison
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