Pcb Tracks-Paths What Sizes And Thicknesses ?

warpie said:

The specific design is all discrete and although I can make the traces thinner I believe that (since I have the room)
wider traces = less resistance (right?). Unless, there's something obvious I'm missing...

It's a line level signal circuit so no high impedances are involved.

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Less resistance, sure, but you're not doing anything with significant current in the traces so there is no worry about voltage drops across the traces or any of that.

-a

Somewhat large-ish traces and pads can be of benefit if you ever have to do re-work since they will have less of a tendency to delaminate/lift during the desoldering and resoldering process.

Bri

JohnRoberts said:

For one more irrelevant comment. I recall the owner of the compnay actively lobbying for filling all empty spaces on PCB so it would deplete the etchant slower. 

JR

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It is certainly a concern in Europe, where PCB manufacturers pay a tax on rejects.

warpie said:

Hi Andy,

The specific design is all discrete and although I can make the traces thinner I believe that (since I have the room)
wider traces = less resistance (right?). Unless, there's something obvious I'm missing...

It's a line level signal circuit so no high impedances are involved.

Thanks
Miek

Click to expand...

Larger traces mean higher capacitance; this may be a concern regarding x-talk. There is not one rule that works for all; you have to analyse the nature and topology of your circuit, and balance the result against manufacturability, mechanical reliability and serviceability.

a clever use of circuit board traces can be seen on the Langevin AM16 layout,

traces run over each other on the front and back to create 10 pf of balanced C across the I/O iron,

took me a while to figure this one out,

CJ said:

a clever use of circuit board traces can be seen on the Langevin AM16 layout,

traces run over each other on the front and back to create 10 pf of balanced C across the I/O iron,

took me a while to figure this one out,

Click to expand...

There are also layout tricks even used with single sided layouts with one conductor of a pair is bracketed or surrounded by the other conductor. This geometry causes a first order cancellation of magnetic fields generated by current flowing both ways in the conductors.

Capacitance is generally not something to increase, but I vaguely recall some old RA Pease articles about impact of stray PCB effects on sensitive circuitry. Trace capacitance can be a stability concern with high impedance NF networks.

JR