Should i use a double sided board and mirrior the same circuit on both sides? Is this a bad idea? I know that it will lower resistance but will it have any negative effects to capacitance, inductance, or EMI and noise from the parallel lines. Is a single sided board better than a double sided with parallel circuits?
Banned
Joined 2002
Banned
Joined 2002
He is not going to place components on both sides.HBarske said:
Just doubles the copper-wires.
But I think it is better to have wider/thicker copper-rails
if you want lower resistance.
Sometimes 2 parallell rails on the board is to prefer instead of one wide.
There are PCBs with different thickness of copper.
Are you talking about putting one channel on one side of the board and the other channel on the other side? Or are you asking if you should just duplicate the layout and essentially connect the two sides in parallel?
If it is the first, I'd say it isn't a good idea. You can't very well mount through-hole components this way, and even if you use surface mount, you'll be capacitively coupling the two channels together at every node in the circuit.
If you're talking about the second configuration, I'd say it probably won't hurt, but you might be better off with a ground plane instead. One thing that is good about two layer boards is plated-through holes. They are much more reliable than non-plated-through holes, especially if you're going to end up swapping components on the board a bunch of times.
MR
If it is the first, I'd say it isn't a good idea. You can't very well mount through-hole components this way, and even if you use surface mount, you'll be capacitively coupling the two channels together at every node in the circuit.
If you're talking about the second configuration, I'd say it probably won't hurt, but you might be better off with a ground plane instead. One thing that is good about two layer boards is plated-through holes. They are much more reliable than non-plated-through holes, especially if you're going to end up swapping components on the board a bunch of times.
MR
Shaun Perez said:
... Or you could use PCB's with thicker copper laminate and save you the troubble. "Normal" PCB's are 1oz copper. You can get 2 and 3 oz copper as well, if you are worried about conductivity.
I have just made some boards for the Mini-A and they are doubble sided with groundplane on top. One advantage is that i get solder pads on both sides of the PCB, thus better mechanical stability for the components.
That is an interesting question. Seems like you are looking for a way to make use of the second side of a 2 sided PCB.
If you used plated through holes, there would not be any (in theory) capacitance issues. It would be like shorting the 2 leads of an axial cap and then using it as a conductor/wire.
I would make use of all that free copper, but I do not think I would double up on the traces.
The idea of the ground plane has merits.
I have heard from a respected audio engineer that the way to go is a true star ground. Each component lead that goes to ground does so via it's own trace, to a single point on the board.
The idea is that while they all go to ground, each component will have its own voltage level and it's own "phasing" (for lack of a better word). The stream of electrons from one lead will not interfere with the stream of another lead.
This would also allow you more room and freedom to do more elegant and direct paths with your signal traces on the non ground side.
I have no 1st hand knowledge, nor have I tested the theory. I am just passing on one respected engineer's idea. I do not feel comfortable divulging the engineer's name, but most people would know the name.
Aud_Mot
If you used plated through holes, there would not be any (in theory) capacitance issues. It would be like shorting the 2 leads of an axial cap and then using it as a conductor/wire.
I would make use of all that free copper, but I do not think I would double up on the traces.
The idea of the ground plane has merits.
I have heard from a respected audio engineer that the way to go is a true star ground. Each component lead that goes to ground does so via it's own trace, to a single point on the board.
The idea is that while they all go to ground, each component will have its own voltage level and it's own "phasing" (for lack of a better word). The stream of electrons from one lead will not interfere with the stream of another lead.
This would also allow you more room and freedom to do more elegant and direct paths with your signal traces on the non ground side.
I have no 1st hand knowledge, nor have I tested the theory. I am just passing on one respected engineer's idea. I do not feel comfortable divulging the engineer's name, but most people would know the name.
Aud_Mot
I don't think doubling the traces will get you anything but a more difficult layout. Your trace resistance should be pretty small, and by the time parasitic inductance and capacitance take effect, you're at a very high frequency already. Trace resistance will have minimal effect, and you'd only gain a 3dB reduction in trace resistance effects for all the paralleled traces. High current traces are another story, since the tiny trace resistance will have some effect, and in this case, it's all about cross-sectional area of the copper.
Ground planes are useful in digital circuits, where you have very high frequency components present, and you need to control things like EMI and transmission line (strip-line) impedances, etc. In an audio frequency circuit, my preference is for star-ground arrangements, as it reduces capacitance to ground and improves the dielectric properties (mostly air vs. mostly FR-4 material) of what stray capacitances are present. In a noisy environment, a ground plane may provide some measure of sheilding effect, but I think it's better to build a proper enclosure and separate "quiet" and "noisy" circuits into different sections of the case, or in different enclosures altogether.
Ground planes are useful in digital circuits, where you have very high frequency components present, and you need to control things like EMI and transmission line (strip-line) impedances, etc. In an audio frequency circuit, my preference is for star-ground arrangements, as it reduces capacitance to ground and improves the dielectric properties (mostly air vs. mostly FR-4 material) of what stray capacitances are present. In a noisy environment, a ground plane may provide some measure of sheilding effect, but I think it's better to build a proper enclosure and separate "quiet" and "noisy" circuits into different sections of the case, or in different enclosures altogether.
Shaun Perez said:
I tried this when laying out my Aleph-X board, but it seemed more difficult then it is worth. I think that I achieved decent symmetry by mainly using one side of the board, and then using the other side for a ground plane and a couple of traces that needed to be routed over the other traces.
Here is my try at a symmetrical Aleph-X layout:
http://brian.prohosting.com/ax/
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Brian
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