Steve,
Haven't seen this exact socket before, but have worked on a few
projects that look similar. Certainly must defer to the "man on the scene",
but from this view point, seem like the more solder, the better. If
you can't easily add paste to the pads with a screen I'd load up
the pin tips with extra solder. If you need a screen to add paste I may have a
few to send out to ya.
Gooood Luck,
Jeff Ferry
CEO
Circuit Technology Center,
Inc.
www.circuittechctr.com
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Hi all!
Got a fresh new beast to deal with that I've never seen before...a
PGA-to-SMT socket. When you look at the board, it looks like a BGA would go
there, but actually
it's a PGA socket that is soldered to SMT pads...this is
a fairly dense socket, 50-mil spacing. The history is that the yeilds are
terrible, and 99.9% of the time when the assembly doesn't play, it's a solder
issue with the sockets.
I've looked closely at these sockets, and
they're not very precise. The pins are strange too. Each pin is about .145"
long, .038" diameter, and have a little .018" diameter, .005" long nub machined
into the end of each pin...this is what sits on the SMT pad and is soldered to.
All the pins are inserted into a 1-inch square, .062" thick FR4 substrate to
form the socket. Go to:
http://www.stevezeva.homestead.com
To
get a look at what I'm about to deal with...I've noticed some coplanarity issues
with the pins too. I've got some ideas to try and deal with that. But have any
of you ever dealt with these little "jewels"? Got any tips?
By the way,
these sockets MUST be used, no choice...
-Steve Gregory-