RE: [SI-LIST] : Different oz copper for grounds

tomda (tom_dagostino@mentorg.com)
Fri, 24 Sep 1999 10:05:36 -0700

You may have an etching problem when trying to etch a board with different
weights of copper on either side. Check with your supplier.

Tom Dagostino

-----Original Message-----
From: MikonCons@aol.com [SMTP:MikonCons@aol.com]
Sent: Thursday, September 23, 1999 5:29 PM
To: si-list@silab.eng.sun.com
Subject: Re: [SI-LIST] : Different oz copper for grounds

Chris:

Benefits are all positive.
1. Better warpage control through equal copper balance in the stackup
2. Better thermal conductivity (minimizes temperature extremes and hot
spots, and lowers associated mechanical stresses...increases
life/reliability)
3. Stiffer (less flexing of PCB with vibration...avoids solder
crystallization and increases reliability)
4. Better shielding of internal signals (frequency for three skin depths
drops by a factor of four relative to 1-ounce copper)
5. Lowers net planar inductance for lower common-mode voltage generation;
hence, lowers radiated emissions
6. etc.

Mike Conn
Owner/Principal Consultant
Mikon Consulting

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