Why not achieve copper balance by adding extra grounded areas on the surface; ie, copper fill pegged to the normal ground layer(s) at multiple points? Large areas can be gridded in some fashion; it doesn't have to be solid copper.
I'm one who does not like to see floating copper, of any size or shape, especially in high frequency areas of a board. Jack Cook Xerox Corp. -----Original Message----- From: Perry Qu [mailto:[email protected]] Sent: Thursday, January 18, 2001 1:19 PM To: Roman, Dan Cc: 'Stephen Phillips'; [email protected]; [email protected]; DORIN OPREA Subject: Re: Copper Thieving Hi! Dan: I understand that EMC guys don't want to see the floating coppers on the PCB because of ESD and/or emission problem. But on the manufacture side, they claim that if you don't do copper balance on the layer where you have large area without copper, you will sure have over-eching in that area, plus warpage of the board. The question is, where do we find a compromised solution that makes everyone happy ? Regards Perry "Roman, Dan" wrote: > Remember that you can also cause yourself all kinds of EMI headaches if you > have electrically floating copper areas or patterns on the board. It has > lead to many arguments with the CAD department over the years! > > -- Dan > > -----Original Message----- > From: Stephen Phillips [mailto:[email protected]] > Sent: Thursday, January 18, 2001 9:33 AM > To: [email protected]; [email protected] > Subject: Re: Copper Thieving > > Copper applied to the outer PCB layers, in a pattern, > to even out the copper placement so the board is less > likely to warp through soldering. Obviously, it would > be put where there is not etch, large open areas, to > somewhat offset where you might have planes of > copper elsewhere on the layer. > > Beware of Creepage and Clearance violations > (if applicable). Some PCB fab. houses have > carte-blanche to add this, we don't allow that - > and control it as part of our own PCB CAD > instead. > > Best regards, > Stephen > > At 09:15 AM 1/18/01 Thursday , [email protected] wrote: > > > >Please excuse my lack of knowledge..........................what is "copper > >thieving"? > > > > > >------------------------------------------- > >This message is from the IEEE EMC Society Product Safety > >Technical Committee emc-pstc discussion list. > > > >To cancel your subscription, send mail to: > > [email protected] > >with the single line: > > unsubscribe emc-pstc > > > >For help, send mail to the list administrators: > > Jim Bacher: [email protected] > > Michael Garretson: [email protected] > > > >For policy questions, send mail to: > > Richard Nute: [email protected] > > > > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
