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From: /S=cc#c#Mail-Gateway/OU2=XSFCC/OU=ZWGBA/P=MOT/A=MOT/C=US/::(SCCCML) at ~FA
BRIK
Date: 1/24/96 9:54AM
To: Andrew P Magee at Rogers-MCD
Subject: Message Undeliverable to cc:Mail
-------------------------------------------------------------------------------
     IPC-MF-150, Metal Foil for Printed Wiring Applications, allows
     thickness tolerances for wrought foils of +/- 5% and deposited foils
     of +/- 10%.

     The maximum thickness has an additional tolerance allowed for the
     various foil profiles. Standard Profile has no maximum specified
     thickness. Low Profile allows an extra 0.40 mils, and Very Low Profile
     allows an additional 0.20 mils.

     These specifications don't directly apply to your case of plated up
     circuits, but they do describe the underlying foil tolerances. It may
     be a starting place for a reasonable standard.


     Andrew P. Magee - Applications Engineer
     Rogers Corp - Circuit Materials Unit
     Tel: (602) 917-5237
     Fax: (602) 917-5256
     E-Mail: [log in to unmask]


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Subject: Copper Thickness Designation
Author:  Richard E Ackerson::(ACKRRE) at ~FABRIK
Date:    1/24/96 6:20 AM


From: Richard E Ackerson
Date: Wed, Jan 24, 1996 6:20 AM
Subject: Copper Thickness Designation
To: TechNet
I am looking for information regarding the way various designers specify
copper thickness for boards, and how this information is translated by the
manufacturers. IPC-D-325A and IPC-D-275 are not clear on how this information
is to be stated or translated.

We have always indicated the copper weight as the starting weight, ie. 2oz,
1oz, 1/2oz, etc.. Some manufacturers translate this designation as finished
weight. They will start with a lighter copper and plate up to a finished
dimension, (start with 1oz, plate up to 2oz).

Tolerances are not stated in the IPC documents. IPC-RB-276 indicates that, in
the case of 2oz copper, the finished surface thickness should be .003".

What is the general direction of the industry? As indicated above, I have had
manufacturers indicate both ways.

Rich Ackerson
Sr. Industrial Engineer
Elsag Bailey Electronics
Voice 216-585-7646
Fax   216-585-8867
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