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2011-04-06 by Andrew
I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well?
2011-04-07 by Terry
Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@...> wrote:
> > I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? >
2011-04-07 by Tom Biery
Yes I do the same see this youTube video http://youtu.be/7I41tVOruug groundplane on both sides if you like please subscribe ________________________________
From: Terry <twgray2007@...> To: Homebrew_PCBs@yahoogroups.com Sent: Wed, April 6, 2011 9:52:40 PM Subject: [Homebrew_PCBs] Re: ground planes - two sides, or just one? Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@...> wrote: > > I am closing in on designing a board that is a mix of SMD and through hole >parts. I am using a zone on the bottom side to provide a ground plane; I >wondered about adding a zone to the top as well. If I did a top zone, is there >any reason I can't make it a ground plane as well? > [Non-text portions of this message have been removed]
2011-04-07 by Adam Shea
Really depends on what you're doing. For my power converter stuff I do a power plane on one side and ground plane on the other as it acts as a nice capacitor to short out ~100MHz kind of stuff. --Adam. On 04/06/11 20:52, Terry wrote: > Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. > > --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@...> wrote: >> >> I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? >> > > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > [Non-text portions of this message have been removed]
2011-04-07 by William Laakkonen
Andrew, I highly recommend reading all the tips at the Hott Consultants web site. As you question is very general, it may help guide you a bit. I worked for a very high precision metrology equipment maker-- we separated analog and digital grounds (actually often compartmentalized them), connected with vias the grounds on upper, lower, and inner layers, guard rings, guard layers, etc-- we had a saying: "all roads lead to Mecca" and you could literally see this in the board layouts. Of course metrology are different than RF, so it depends on what you're building and the frequency domains involved. The best resource I have found: http://www.hottconsultants.com/techtips/split-gnd-plane.html Good luck with your design. Best regards, Bill Laakkonen On Wed, Apr 6, 2011 at 7:19 PM, Andrew <a_wake@...> wrote: > > > I am closing in on designing a board that is a mix of SMD and through hole > parts. I am using a zone on the bottom side to provide a ground plane; I > wondered about adding a zone to the top as well. If I did a top zone, is > there any reason I can't make it a ground plane as well? > > > [Non-text portions of this message have been removed]
2011-04-07 by Jeanette
I just made some low-impedance boards for power supply regulators. Using a star ground on the bottom of the board, at the nucleus I punched a 0.031" hole. On the top side I poured a copper layer attached to no net. When the boards were finished I just connect the star ground nucleus to the top side layer. Since the layer on the top isn't connected to a net, component ground connections are only made through the star system, ergo elimination of ground loop conductance. Probably not good practice for RF, but it really works for very low impedance power supply regulators. --- In Homebrew_PCBs@yahoogroups.com, "Terry" <twgray2007@...> wrote:
> > Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. > > --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@> wrote: > > > > I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? > > >
2011-04-07 by Andrew
Adam, This gets at an issue I was wondering about -- I was aware of designs that have a power plane on one side and ground plane on the other, and was not sure what the advantage would be, though I suspected it might involve some capacitance. I wondered whether that capacitance was always a positive phenomenon, or could ever be negative. But for this particular board, the issue is moot -- there are three different voltages on the board, and the layout would prevent any of them from filling much of a zone. Thus I was thinking about a ground plane on top ... but wondered if there were any possible negative effects of doing so. Thanks for the input -- it helps to relieve a little of my woeful ignorance! --- In Homebrew_PCBs@yahoogroups.com, Adam Shea <shea0097@...> wrote:
> > Really depends on what you're doing. For my power converter stuff I do > a power plane on one side and ground plane on the other as it acts as a > nice capacitor to short out ~100MHz kind of stuff. > > --Adam. > > On 04/06/11 20:52, Terry wrote: > > Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. > > > > --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@> wrote: > >> > >> I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? > >> > > > > > > > > > > ------------------------------------ > > > > Be sure to visit the group home and check for new Links, Files, and Photos: > > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > > > > > > > > > [Non-text portions of this message have been removed] >
2011-04-07 by Andrew
Thanks, Bill, I will check this out. --- In Homebrew_PCBs@yahoogroups.com, William Laakkonen <worldradiolabs@...> wrote:
> > Andrew, > > I highly recommend reading all the tips at the Hott Consultants web site. As > you question is very general, it may help guide you a bit. I worked for a > very high precision metrology equipment maker-- we separated analog and > digital grounds (actually often compartmentalized them), connected with vias > the grounds on upper, lower, and inner layers, guard rings, guard layers, > etc-- we had a saying: "all roads lead to Mecca" and you could literally see > this in the board layouts. Of course metrology are different than RF, so it > depends on what you're building and the frequency domains involved. > > The best resource I have found: > http://www.hottconsultants.com/techtips/split-gnd-plane.html > > Good luck with your design. > > Best regards, > > Bill Laakkonen > > On Wed, Apr 6, 2011 at 7:19 PM, Andrew <a_wake@...> wrote: > > > > > > > I am closing in on designing a board that is a mix of SMD and through hole > > parts. I am using a zone on the bottom side to provide a ground plane; I > > wondered about adding a zone to the top as well. If I did a top zone, is > > there any reason I can't make it a ground plane as well? > > > > > > > > > [Non-text portions of this message have been removed] >
2011-04-07 by Andrew
Tell me more about "ground loop conductance" -- this sounds like the kind of thing that I was concerned about, though without really knowing what or why. --- In Homebrew_PCBs@yahoogroups.com, "Jeanette" <jdwalton@...> wrote:
> > I just made some low-impedance boards for power supply regulators. Using a star ground on the bottom of the board, at the nucleus I punched a 0.031" hole. On the top side I poured a copper layer attached to no net. When the boards were finished I just connect the star ground nucleus to the top side layer. Since the layer on the top isn't connected to a net, component ground connections are only made through the star system, ergo elimination of ground loop conductance. Probably not good practice for RF, but it really works for very low impedance power supply regulators. > > --- In Homebrew_PCBs@yahoogroups.com, "Terry" <twgray2007@> wrote: > > > > Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. > > > > --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@> wrote: > > > > > > I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? > > > > > >
2011-04-07 by David C. Partridge
Henry Ott's book "Electromagnetic Compatability Engineering" is "the bible" in this arena. Dave
-----Original Message----- From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Andrew Sent: 07 April 2011 15:07 To: Homebrew_PCBs@yahoogroups.com Subject: [Homebrew_PCBs] Re: ground planes - two sides, or just one? Tell me more about "ground loop conductance" -- this sounds like the kind of thing that I was concerned about, though without really knowing what or why.
2011-04-07 by Adam Shea
There can be problems with having large planes near high frequency signals as you get more capacitive loading, but I usually work on power converter stuff where huge copper pours are about the only effective way to both get heat out and to absorb 100MHz range ringing from 40V/ns edges. --Adam. On 04/07/11 08:23, Andrew wrote: > Adam, > > This gets at an issue I was wondering about -- I was aware of designs that have a power plane on one side and ground plane on the other, and was not sure what the advantage would be, though I suspected it might involve some capacitance. I wondered whether that capacitance was always a positive phenomenon, or could ever be negative. > > But for this particular board, the issue is moot -- there are three different voltages on the board, and the layout would prevent any of them from filling much of a zone. Thus I was thinking about a ground plane on top ... but wondered if there were any possible negative effects of doing so. > > Thanks for the input -- it helps to relieve a little of my woeful ignorance! > > --- In Homebrew_PCBs@yahoogroups.com, Adam Shea <shea0097@...> wrote: >> >> Really depends on what you're doing. For my power converter stuff I do >> a power plane on one side and ground plane on the other as it acts as a >> nice capacitor to short out ~100MHz kind of stuff. >> >> --Adam. >> >> On 04/06/11 20:52, Terry wrote: >>> Generally speaking, the more ground plane -- top and bottom -- the better. The last step in most of my designs is to do a polygon fill tied to GND on both sides of the board. >>> >>> --- In Homebrew_PCBs@yahoogroups.com, "Andrew" <a_wake@> wrote: >>>> >>>> I am closing in on designing a board that is a mix of SMD and through hole parts. I am using a zone on the bottom side to provide a ground plane; I wondered about adding a zone to the top as well. If I did a top zone, is there any reason I can't make it a ground plane as well? >>>> >>> >>> >>> >>> >>> ------------------------------------ >>> >>> Be sure to visit the group home and check for new Links, Files, and Photos: >>> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links >>> >>> >>> >> >> >> >> >> [Non-text portions of this message have been removed] >> > > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > [Non-text portions of this message have been removed]