PCB building: 2 sided - vias, through holes etc.

[burningman]

I have kept away from building with 2 sided boards for a while now simply because I don't know how to bridge the two layers when needed.
What methods have people used (vias, through holes etc) and how would I go about it. Thanks BM

[theehman]

Just use a component lead soldered on both sides.

[John Lyons]

Just print the second layer (top layer) reversed (horizontally) and do this.
Cut out your trace patterns with an inch all the way around.
Take the two printouts and line them up with a bright light behind to get
them aligned perfectly. Take a piece of tape and fold it over both layers
and on 3 sides making a pocket. Slip in your PCB and iron on both sides
of a double sided PCB. Tada!

Any layers you need to join can be done via a component lead or bare
wire soldered on both sides. Since home built PCBs do not have through
hole plating you will need to solder any pads on the top of the board that
connect to traces on the bottom.

john

[burningman]

Thanks guys. I should have thought of the component lead trick earlier - so simple.

One more question: do you reserve one side of the PCB for power buses/planes, and the other for signal traces?

[John Lyons]

For most of the pedals we do I don't think it matters.
Some digital circuits may be sensitive to it...

John

[burningman]

how would a pcb design for digital electronics differ?

[Taylor]

A lot of digital effects, like some Boss pedals, have separate digital and analog grounds. Keeping them separate and only connected them at a single point keeps digital noise out of the analog signal path.

[burningman]

Is difference in voltages that are the problem with mixing digital and analog grounds or something else?
For instance, would a DC/DC converter solve this by isolating the different voltage requirements of a circuit (ie. microcontroller from guitar signal/buffer)?
thanks, BM

[John Lyons]

The problem is keeping the ground pure. One analog and one digital.
The digital ground will have clock noise and or other noise that will
contaminate the analog ground, ticking and humming etc. By isolating the
ground and connecting them through a small resistance and or at only point
only as in star grounding you can have a quite circuit.

The voltages aren't the issue.

john

[burningman]

Thanks for the explanation, I think I understand the differences now.
I should really invest in RG's layout book.

[John Lyons]

His book does not cover these issues though.
It is mainly about making a compact layout
and working from a schematic.

John