David, Can you use guard tracks? - tracks driven at the same voltage as the ones you're concerned with (e.g. from a buffer). Then place these guard tracks between the "tracks of concern". Since the adjacent track will be at the same voltage as the sensitive trace there will be no capacitive loading. All loading will be be between the 2 guard tracks which doesn't change the reading. RP On 20 March 2018 at 06:15, louijp@gmail.com wrote: > David,If you use layer 3 or 4, the values will be very close, so the > series kind of cancel itself. Better avoid parallel connections. Usage is > to use perpendicular flow of traces on nearby layers to minimize > interaction.Just another thought,Jean-Paul N1JPL > > Sent from Yahoo Mail on Android > > On Mon, Mar 19, 2018 at 12:51 PM, Van Horn, David backcountryaccess.com> wrote: > A fun thought: > > I have a PCB with six layers. I am looking for ways to minimize > capacitive coupling between tracks on the top and tracks on the bottom. > > If I think of the tracks as parallel plates, and the PCB as the > dielectric, then that gives me a certain C, a bit bigger than suggested b= y > the directly overlapping area. > > Now what happens if I put a small copper dot, floating, in layer 3 or 4? > It seems like this should create a series pair of capacitors of about twi= ce > the value, and no net change, but I keep thinking that the end result has > to be a little less C than the first case. > > Is there something freeware-ish that I can use to model a three (or more) > plate capacitor where the middle plates are floating? > > > -- > David VanHorn > Lead Hardware Engineer > > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > phone: 303-417-1345 x110 > email: david.vanhorn@backcountryaccess.com backcountryaccess.com> > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .