Hi ya'll...

I guess I'm on a roll now...just want to vent about manufacturability issues
with SMT components. I've been exposed to issues at my present position with
certain devices that create nightmares when trying to build the assemblies.
This is aside from the issue that I have with the BGA device I've been
posting about, there's more...

There's an assembly that we build here that has two 352-pin ceramic 20-mil
pitch, gold plated leads, QFP's that only comes in a carrier that has to be
pre-tinned, cut and formed, prior to placement and reflow. We do the
pre-tinning and cut and form ourselves in-house with a Mannix press and
adjustable die. You can imagine what fun that is...

My question is (and I'm pretty sure I won't get a good answer) why in heaven
do the component vendors supply the parts only this way?

I've checked with them and the configuration that the components are
supplied, is the only way they come...they won't pre-tin and form them. I'll
just leave it up to your imagination who the supplier is....

WHY? OH WHY? Obvoiusly the parts are meant to be surface mounted, why not cut
and form them into a standard foot-print? The issues with gold embrittlement
are old as dirt, why do they still supply parts this way?

Further still, why do I have to do it? I wouldn't mind paying more for
pre-tinned and formed parts either! HONEST!!!

If any of you have had the pleasure of pre-tinning, and then cut and forming
20-mil pitch QFP's, you know my agony...

If there is anybody from the component vendor arena reading the list, I would
like to understand your views on the issues...

Sorry if I seem to be beating-up on the component vendors today...but I've
been having nightmares lately about this stuff...

-Steve Gregory-

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