Geoff,

It's a common practice to have SS separators and CAC in the same press load.
As the heat increases the bond (glue) between the copper and aluminum breaks
(strain forces) allowing for a slip plane. The b-stage (between layers 1 & 2
and X & n) is still in melt mode and consequently any frictional force
created between the dissimilar metals is not transmitted to the core, no
distortion and (hopefully) good registration.

We have an issue with separators that need to be replaced and I'm trying to
avoid the capital spend at this time. CSC is way to expensive for us as the
market won't bear the price increase we'd have to charge for using this
material.

So...........just looking for anyone not using any separators (except those
against the caul) as a standard practice.

Regards,

John S. Grosso
Waytec Electronics Corporation
Vice President of Quality & Engineering
(434) 237-6391 x130
[log in to unmask]



-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Geoff Layhe
Sent: Tuesday, April 29, 2003 12:26 PM
To: [log in to unmask]
Subject: Re: [TN] USE OF CAC / SEPARATORS


John,
Are you using CAC AND stainless separators in the same press load? That must
set up a lot of stresses due to the different CTE of aluminium, copper,
steel, & laminate. I would use one or the other but not both.

Have you looked at copper steel copper (CSC)? This gives good results for
high layer counts.

Geoff Layhe

-----Original Message-----
From: John S. Grosso [mailto:[log in to unmask]]
Sent: Tuesday, April 29, 2003 2:53 PM
To: [log in to unmask]
Subject: [TN] USE OF CAC / SEPARATORS


Process statement:

In our lamination process we use CAC with a .020 aluminum core, no SS
separators for product 8 layers and less. For > 8 layers we use CAC but
with a SS .062 separator between each panel.

Question:

Is anyone having success running straight CAC on > 8 layers? What level of
image transfer are you seeing and on what copper weight? Any issues with
distortion due to dissimilar CTE's? Any issues with tight dielectric
thickness control? What type of press cycles are being run? What are your
temperature rise profiles? What type of thermal lagging is being used?

Regards,

John S. Grosso

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------


Private & Confidential:
This e-mail message is confidential and is intended solely for the person or
organisation to whom it is addressed.  If the message is received by anyone
other than the addressee please return the message to the sender by replying
to it and then delete the message from your computer.

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------

---
Incoming mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.462 / Virus Database: 261 - Release Date: 3/13/2003

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------