It sounds as if you could all do with a couple of weeks in a pcb
manufacturing shop to understand how the boards you order  are made

Talk to your boss and suggest it, you may learn a lot

Paul Brown

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Stephen R. Gregory
Sent: 06 October 1999 20:57
To: [log in to unmask]
Subject: [TN] Two distinct layers of copper...

Hi ya'll!

Here's something weird I've never come across, but maybe some of you have.
We
built this Hi-Rel board here that the PCB drawing calls out for 2-ounce
copper.

The board has this leaded SMT multi-capacitor part (it's like 3 huge ceramic
capacitors stacked on top of each other) and has 8-leads. After assembly,
and
before we test then conformal coat it, we put the assembly on this vibration
table to go through some ESS.

There's been a few of these capacitor deals come loose because they're so
top
heavy, but that's a whole 'nuther issue...

What we've been seeing on some of these boards, is that either the pad
completely lets go from the laminate (it's a polyimide), or sometimes we'll
see the pad come up in what looks like a layer of copper, yet there's still
copper down on the PCB...as if the copper has split horizontally in two
distinct layers? Is this possible? Does 2-ounce copper clad laminate get the
copper plated an ounce at a time? Is this a defect? I've never seen
something
like this before, and I can take a picture and send it to ya' if you want me
to....

Thanks!

-Steve Gregory-

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################

##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe:   SUBSCRIBE TECHNET <your full name>
To unsubscribe:   SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################